Patent Publication Number: US-2022211519-A1

Title: Carpometacarpal (cmc) implants and methods

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     The present application is a continuation of the co-pending U.S. patent application Ser. No. 16/940,429, filed on Jul. 28, 2020, which is a divisional application of U.S. patent application Ser. No. 15/085,796, filed on Mar. 30, 2016, (now U.S. Pat. No. 10,758,374), which claims priority benefit of U.S. Provisional Application No. 62/141,186, filed on Mar. 31, 2015. 
    
    
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 C.F.R. § 1.57 for all purposes. 
     BACKGROUND 
     Field 
     This disclosure relates generally to implants, and, more specifically, to hydrogel joint implants and various tools, devices, systems, and methods related thereto. 
     Description of Related Art 
     Implants can be used to replace deteriorated or otherwise damaged cartilage within a joint. Such devices can be used to treat osteoarthritis, rheumatoid arthritis, other inflammatory diseases, generalized joint pain, joints damaged in an accident, joints damaged while participating in athletics, joints damaged due to repetitive use, and/or other joint diseases. 
     SUMMARY 
     In some embodiments, an implant comprises, or alternatively consists essentially of, a hydrogel body comprising an upper surface, a planar lower surface opposite the upper surface, and sidewalls extending between the upper surface and the lower surface. The upper surface comprises a saddle shape. The sadly shape includes a first peak, a second peak, a first trough, and a second trough. The first trough is laterally between the first peak and the second peak. The second trough is laterally between the first peak and the second peak. The first peak is laterally between the first trough and the second trough. The second peak is laterally between the first trough and the second trough. 
     The hydrogel may comprise polyvinyl alcohol (PVA). The hydrogel may comprise water. The hydrogel may comprise saline. The upper surface may be contoured to correspond to an outer surface of a trapezium. The body may have a diameter between 4 mm and 8 mm. The implant may be load bearing. The implant may be non-biodegradable. The implant may be configured to be placed in a carpometacarpal joint. The lower surface may be configured to be placed in a cavity in a first metacarpal bone. The upper surface may be configured to abut a trapezium. A distance between at least one of the first peak and the second peak and the planar lower surface may be between 10% and 20% greater than a distance between at least one of the first trough and the second trough and the planar lower surface. 
     In some embodiments, a placer comprises, or alternatively consists essentially of, a first end, a second end opposite the first end, and a body extending between the first end and the second end. The first end comprises a saddle shape. The saddle shape includes a first peak, a second peak, a first trough, and a second trough. The first trough is laterally between the first peak and the second peak. The second trough is laterally between the first peak and the second peak. The first peak is laterally between the first trough and the second trough. The second peak is laterally between the first trough and the second trough. 
     The placer may further comprise a lumen extending through the body from the first end to the second end. The lumen may be configured to facilitate placement of a guide pin. The placer may further comprise a measurement band proximate to the second end. The measurement band may comprise a plurality of measurement bands spaced by 1 mm. The first end may be contoured to correspond to an outer surface of a first metacarpal bone. 
     In some embodiments, a drill bit comprises, or alternatively consists essentially of, a distal end, a proximal end opposite the distal end, and a body extending between the distal end and the proximal end. The distal end comprises a flange and a plurality of cutters distal to the flange. The flange has a lateral dimension greater than a lateral dimension of the body. The proximal end is configured to be coupled to a drill. 
     The plurality of cutters may comprise three cutters. The plurality of cutters may be spaced 120° from each other. Each of the plurality of cutters may extend from a hub. The drill bit may further comprise a lumen extending through the body from the proximal end to the distal end. The lumen may be configured to be tracked over a guide pin. The proximal end may comprise a polygonal lateral cross-section. 
     In some embodiments, an introducer comprises, or alternatively consists essentially of, a distal end, a proximal end opposite the distal end, and a body extending between the distal end and the proximal end. The distal end comprises a neck portion. The body is coupled to the neck portion at a shoulder. The body comprises a lumen including a flared shape proximate to the proximal end. 
     The body may comprise alignment indicia. The body may be cylindrical. 
     In some embodiments, a plunger comprises, or alternatively consists essentially of, a distal end, a proximal end opposite the distal end, and a body extending between the distal end and the proximal end. The distal end comprises a saddle shape. The saddle shape includes a first peak, a second peak, a first trough, and a second trough. The first trough is laterally between the first peak and the second peak. The second trough is laterally between the first peak and the second peak. The first peak is laterally between the first trough and the second trough. The second peak is laterally between the first trough and the second trough. The proximal end comprises a head portion. 
     The distal end may be configured to abut an end surface of an implant contoured to abut a trapezium. The body may comprise alignment indicia. The head portion may comprise a T-shaped handle. The body may comprise alignment indicia. The body may be cylindrical. 
     In some embodiments, a deployment system comprises, or alternatively consists essentially of, the introducer and the plunger. 
     The body of the plunger may be configured to extend at least partially through the lumen of the introducer. The plunger may be configured distally advance an implant through the lumen of the introducer. The plunger may be radially inwardly compress an implant in the lumen of the introducer. The plunger may be configured deploy an implant out of the distal end of the introducer. 
     In some embodiments, a kit comprises, or alternatively consists essentially of, at least two of the placer, the drill bit, the introducer, the plunger, and a guide pin. 
     The kit may further comprise the implant. 
     In some embodiments, a method of positioning an implant in a carpometacarpal joint comprises, or alternatively consists essentially of, aligning an implant deployment system with a recess in a carpometacarpal bone. The carpometacarpal bone comprises the first metacarpal bone. The joint comprises a surface of a trapezium. The recess faces a carpometacarpal joint. The implant deployment system comprises an introducer comprising first alignment indicia and a plunger comprising second alignment indicia. The method further comprises deploying the implant out of the implant deployment system partially and partially into the recess. The implant comprises a contoured upper surface contoured to abut the surface of the trapezium. The contoured upper surface comprises a first peak, a second peak, a first trough laterally between the first peak and the second peak, and a second trough laterally between the first peak and the second peak. The first peak is laterally between the first trough and the second trough. The second peak is laterally between the first trough and the second trough. After deployment, the implant is 1 mm to 3 mm proud. 
     Aligning the implant deployment system may comprise aligning the first alignment indicia with a surface feature of the carpometacarpal bone. The method may further comprise loading the implant in the implant deployment system. Loading the implant may comprise aligning the contoured upper surface of the implant with at least one of the first alignment indicia and the second alignment indicia. The method may further comprise radially compressing the implant in the implant deployment system by distally urging the implant through a lumen of the introducer using the plunger. 
     In some embodiments, a method of positioning an implant in a carpometacarpal joint comprises, or alternatively consists essentially of, aligning an implant deployment system with a recess in a carpometacarpal bone and deploying the implant out of the implant deployment system partially and partially into the recess. The recess faces a carpometacarpal joint. The implant comprises a contoured upper surface. 
     The carpometacarpal bone may comprise the first metacarpal bone. The joint may comprise a surface of a trapezium. The upper surface of the implant may be contoured to abut the surface of the trapezium. An introducer of the implant deployment system may comprise alignment indicia. Aligning the implant deployment system may comprise aligning the alignment indicia with a surface feature of the carpometacarpal bone. Aligning the implant deployment system may comprise positioning neck portion of an introducer of the implant deployment system at least partially in the recess. Aligning the implant deployment system may comprise abutting a shoulder of an introducer of the implant deployment system against a surface of the carpometacarpal bone. The implant may comprise one of the implants described above. After deployment, the implant may be 1 mm to 3 mm proud. The deployment system may comprise one of the introducers described above. The deployment system may comprise one of the plungers described above. The deployment system may comprise one of the deployment systems described above. The method may further comprise loading the implant in the implant deployment system. Loading the implant may comprise aligning the implant in the implant deployment system. An introducer of the implant deployment system may comprise alignment indicia. A plunger of the implant deployment system may comprise alignment indicia. A plunger of the implant deployment system may comprise a contoured distal end. The method may further comprise radially compressing the implant in the implant deployment system. Radially compressing the implant in the implant deployment system may comprise distally urging the implant through a lumen of an introducer of the implant deployment system using a plunger of the implant deployment system. The lumen of the introducer of the implant deployment system may comprise a flared shape. Deploying the implant may comprise urging the implant through a lumen of an introducer of the implant deployment system using a plunger of the implant deployment system. Deploying the implant may be manual. Deploying the implant may comprise distally advancing a head portion of a plunger. Deploying the implant may be mechanically assisted. The method may further comprise forming an incision proximate to the carpometacarpal joint. The method may further comprise moving the carpometacarpal bone to expose the carpometacarpal joint. The method may further comprise tamping a guide pin in the carpometacarpal bone. Tamping the guide pin may comprise using a placer. The placer may comprise one of the placers described above. The method may further comprise, before deploying the implant, removing the guide pin. The method may further comprise forming the recess in the carpometacarpal bone. Forming the recess in the carpometacarpal bone may comprise using a drill bit. Using the drill bit may comprise tracking the drill bit over a guide pin. The drill bit may comprise one of drill bits described above. The drill bit may comprise a flange. Forming the recess in the carpometacarpal bone may comprise abutting a surface of in the carpometacarpal bone with the flange. The method may further comprise measuring a depth of the recess in the carpometacarpal bone. Measuring the recess may comprise using an end of a placer comprising measurement bands. Measuring the recess may comprise comparing a feature of a surface of the carpometacarpal bone to the measurement bands. The feature of the surface of the carpometacarpal bone may comprise a peak. The feature of the surface of the carpometacarpal bone may comprise a trough. Measuring the recess may comprise comparing a lateral dimension of the recess in the carpometacarpal bone to a lateral dimension of a placer. The placer may comprise one of placers described above. The method may further comprise, after measuring the recess, increasing at least one of a depth and a diameter of the recess. The method may further comprise, after deploying the implant, moving the carpometacarpal bone to close the carpometacarpal joint. 
     The carpometacarpal bone may comprise the first metacarpal bone. The joint may comprises a surface of a trapezium. The upper surface of the implant may be contoured to abut the surface of the trapezium. An introducer of the implant deployment system may comprise alignment indicia. Aligning the implant deployment system may comprise aligning the alignment indicia with a surface feature of the carpometacarpal bone. The upper surface of the implant may comprise a first peak, a second peak, a first trough laterally between the first peak and the second peak, a second trough. The second trough may be laterally between the first peak and the second peak, the first peak may be laterally between the first trough and the second trough, and the second peak may be laterally between the first trough and the second trough. After deployment, the implant may be 1 mm to 3 mm proud. The implant deployment system may comprise an introducer comprising first alignment indicia and a plunger comprising second alignment indicia. Loading the implant may comprise aligning the contoured upper surface of the implant with at least one of the first alignment indicia and the second alignment indicia. The method may further comprise radially compressing the implant in the implant deployment system by distally urging the implant through a lumen of an introducer of the implant deployment system using a plunger of the implant deployment system. The method may further comprise tamping a guide pin in the carpometacarpal bone using a placer. The method may further comprise forming the recess in the carpometacarpal bone using a drill bit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain features, aspects, and advantages of the disclosure are described with reference to drawings, which are intended to illustrate, but not to limit, the various inventions disclosed herein. It is to be understood that the attached drawings are for the purpose of illustrating concepts and embodiments of the disclosure and may not be to scale. 
         FIG. 1A  is a bottom and side perspective view of an example carpometacarpal implant. 
         FIG. 1B  is a top and side perspective view of the implant of  FIG. 1A . 
         FIG. 1C  is a top plan view of the implant of  FIG. 1A . 
         FIG. 2A  is a side perspective view of an example placer. 
         FIG. 2B  is a first end and side perspective view of the placer of  FIG. 2A . 
         FIG. 2C  is a second end and side perspective view of the placer of  FIG. 2A . 
         FIG. 3A  is a side and bottom perspective view of an example drill bit. 
         FIG. 3B  is a side perspective view of the drill bit of  FIG. 3A . 
         FIG. 3C  is a bottom plan view of the drill bit of  FIG. 3A . 
         FIG. 3D  is a top and side perspective view of the drill bit of  FIG. 3A . 
         FIG. 4A  is a side and bottom perspective view of an example introducer. 
         FIG. 4B  is a side and top perspective view of the introducer of  FIG. 4A . 
         FIG. 5A  is a side and bottom perspective view of an example plunger. 
         FIG. 5B  is a side perspective view of the plunger of  FIG. 5A . 
         FIGS. 6A-6Z  schematically illustrate an example method of positioning an example carpometacarpal implant. 
     
    
    
     DETAILED DESCRIPTION 
     The discussion and the figures illustrated and referenced herein describe various embodiments of a cartilage implant, as well as various tools, systems, and methods related thereto. A number of these devices and associated treatment methods are particularly well suited to replace deteriorated or otherwise damaged cartilage within a joint. Such implants are configured to remain within the patient&#39;s joint on a long-term basis (e.g., for most or all of the life of the patient or subject), and, as such, are configured, in some embodiments, to replace native cartilage. In some embodiments, an implant is configured to be substantially non-biodegradable and/or non-erodable. In some embodiments, an implant is configured to remain within the patient&#39;s joint or other portion of the anatomy for a minimum of 10 years, up to 100 years (e.g., about 10 years, about 20 years, about 25 years, about 30 years, about 35 years, about 40 years, about 45 years, about 50 years, about 55 years, about 60 years, about 65 years, about 70 years, about 75 years, about 80 years, about 85 years, about 90 years, about 95 years, about 100 years, duration ranges between the foregoing values, etc.) without losing structural and/or physical properties and/or without losing ability to function as a cartilage replacement component or device. In some embodiments, an implant is configured to remain within the anatomy for greater than 100 years without losing structural and/or physical properties and/or without losing ability to function as a cartilage replacement component. Certain implants described herein can be used to treat osteoarthritis, rheumatoid arthritis, other inflammatory diseases, generalized joint pain, joints damaged in an accident, joints damaged while participating in athletics, joints damaged due to repetitive use, and/or other joint diseases. However, the various devices, systems, methods, and other features of the embodiments disclosed herein may be utilized or applied to other types of apparatuses, systems, procedures, and/or methods, including arrangements that have non-medical benefits or applications. 
     Certain embodiments described herein may be advantageous because they include one, several, or all of the following benefits: (i) improved treatment of the carpometacarpal joint; (ii) improved coupling of disparate implant materials; (iii) improved cavity wall apposition; (iv) improved implant site preparation tooling and/or systems; (v) improved implant site preparation methods; (vi) improved implant deployment tooling and/or systems; and/or (vii) improved implant deployment methods. 
     Thumb arthritis or basal joint arthritis can be caused by cartilage in the joint at the base of the thumb wearing out or being damaged. Thumb arthritis can cause debilitating hand pain, making simple tasks, such as turning door knobs, sink faucets, and other activities, difficult. Treatment has generally been limited to immobilization, pain relief medicaments, removal of the trapezium, and/or ligament reconstruction and tendon interposition (LRTI). While these treatments may reduce pain, they inhibit function of the thumb and the hand and may result in further or ongoing medicament use. Devices (e.g., implants), systems, kits, and methods described herein can provide a treatment for thumb arthritis that preserves the trapezium. 
       FIG. 1A  is a bottom and side perspective view of one embodiment of a carpometacarpal (CMC) implant  100 .  FIG. 1B  is a top and side perspective view of the implant  100  of  FIG. 1A .  FIG. 1C  is a top plan view of the implant  100  of  FIG. 1A . In some embodiments, the implant  100  comprises, or alternatively consists essentially of, a hydrogel, such as, for example, polyvinyl alcohol (PVA), other polymeric materials, and/or the like. In some embodiments, the PVA content of a hydrogel is about 40% by weight. The PVA content of hydrogel in an implant  100  can be less than or more than about 40% by weight (e.g., about 10%, about 15%, about 20%, about 25%, about 30%, about 32%, about 34%, about 36%, about 37%, about 38%, about 39%, about 41%, about 42%, about 43%, about 44%, about 46%, about 48%, about 50%, about 55%, about 60%, about 65%, about 70%, less than about 10%, more than about 70%, ranges between such values, etc.), as desired or required. 
     The hydrogel of the implant  100 , as well as other implants disclosed herein, can comprise water, saline, other liquids, combinations thereof, and/or the like. In some embodiments, saline may be used instead of water, because, under certain circumstances, saline can help maintain osmotic balance with surrounding anatomical tissues following implantation. The exact composition of hydrogel in an implant  100  (e.g., PVA or other hydrogel materials, water, saline or other liquids, other additives, etc.) can be selected so as to provide the implant  100  with the desired or required strength, load bearing capacity, compressibility, flexibility, longevity, durability, resilience, coefficient of friction, and/or other properties and characteristics. In some embodiments, any hydrogel portion of the implants disclosed herein consist essentially of saline and PVA. In some embodiments, such hydrogel portions of the implants do not comprise any additional additives (e.g., growth factors, surface or other coatings, etc.). In addition, according to some embodiments, the hydrogel portions of any of the implant configurations disclosed herein comprise a consistent concentration (e.g., no concentration gradients), density, and/or other chemical and/or physical properties throughout. 
     In some embodiments, the implant  100 , as well as other implants disclosed herein, is configured or adapted for drug delivery and/or is seeded with growth factors and/or cells. In some embodiments, the implant  100  comprises one or more of the following: chondrocytes, growth factors, bone morphogenetic proteins, collagen, hyaluronic acid, nucleic acids, and stem cells. Such factors and/or any other materials included in the implant  100  and selectively delivered to an implant site can help facilitate and/or promote the long-term fixation of the implant  100  at the joint or other target area of the anatomy. 
     In some embodiments, the hydrogel comprises PVA and/or any other polymeric material. In some embodiments, the content of PVA in the hydrogel is between about 35% and about 45% by weight (e.g., about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, ranges between such values, etc.). In some embodiments, the content of PVA in the hydrogel is greater than about 45% by weight (e.g., about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, greater than about 70%, ranges between such values, etc.) or less than about 35% by weight (e.g., about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, ranges between such values, less than about 5%, etc.). In some embodiments, the content of PVA or other component in the hydrogel is about 40% by weight. 
     In some embodiments, the implant  100  is load bearing and generally non-biodegradable (e.g., non-bioerodable). In some embodiments, the implant  100  is configured or adapted for placement in at least one of a toe, finger, ankle, knee, shoulder, hip, or any other joint, preferably a carpometacarpal joint and more preferably between a first metacarpal bone and a trapezium. In some embodiments, a transition between the upper surface  102  and the sidewalls  106  is generally arcuate, curved, or otherwise smooth, for example compared to including an angle or corner. In some embodiments, such a transition can be non-curved or non-smooth, as desired or required. 
     In some embodiments, the implants disclosed herein are configured for anchoring during implantation. The implant can comprise one or more anchor sites (e.g., comprising non-hydrogel portions or tabs) to facilitate anchoring (e.g., suturing, stapling, etc.). In some embodiments, the implant is pre-coupled to one or more anchors. Such anchors can comprise removable and/or permanent fixtures. In some embodiments, the anchors are resorbable or otherwise dissolvable after implantation (e.g., following a particular time period, such as, for instance, 1-30 days, 2-30 weeks, 6-12 months, 1-5 years, greater than 5 years, less than 1 day, etc.). In some embodiments, the implant comprises at least one abrasive surface. In some embodiments, the implant comprises one or more adhesive components. In some embodiments, one or more implant surfaces can be configured to promote bone adhesion by one or more coatings, substances, and/or the like and/or by using an appropriate surface texture along the surface(s). For example, the implant surface can be roughened, can include pores (e.g., superficial pores), and/or can include any other feature, as desired or required. 
     In some embodiments, the implants disclosed herein are supported or reinforced by a rigid support frame, such as a ceramic, metallic, or other type (e.g., plastic, composite, etc.) of frame. In some embodiments, the implants disclosed herein are supported or reinforced by a flexible or rigid mesh structure. In some embodiments, the implants do not contain or are substantially free or free of any support or reinforcement structure. 
     Any of the implant embodiments disclosed herein, or equivalents thereof, can be manufactured using freeze/thaw cycling and/or any other production method. For example, a hydrogel formulation comprising water, saline, PVA (and/or other hydrogel materials), other polymeric materials, other additives, and/or the like can be heated and/or otherwise treated as part of a freeze/thaw manufacturing process. 
     In some embodiments, a hydrogel solution comprising saline and about 40% PVA by weight is heated to about 121° C. under elevated pressure conditions (e.g., to effect dissolution of the polymer). For example, such a solution can be autoclaved to facilitate complete or substantially complete dissolution of the PVA in the saline, water, and/or other liquid. Next, the temperature and/or pressure of the solution can be lowered to permit entrapped air and/or other gases to escape. In some embodiments, after the autoclaving or similar step, the solution is generally maintained at a temperature of approximately 95° C. and atmospheric pressure for a predetermined time period. 
     The solution can then be transferred (e.g., pumped, poured, etc.) into an open mold where, once set, the solution forms the desired shape of the implant. The mold can include a plurality of individual mold cavities, each of which is configured to receive a hydrogel solution to form an implant. The hydrogel solution may be configured to fill only a lower portion of a cavity of a mold, or the cavity can be filled with the hydrogel solution to a level above the lower portion of the cavity including an upper portion of the cavity. The cavity of the mold can be shaped, sized, and/or otherwise configured so that the implant formed therein comprises a desired configuration. Once the implant has been molded, the implant can be removed from the mold. The implant can be removed either after initial formation or after undergoing additional treatment (e.g., freeze/thaw cycling, other heat and/or pressure treatment, etc.). The implant may be cut, altered, or otherwise processed. For example, a portion of the implant formed in an upper portion of the cavity may be excised and discarded as part of a subsequent reshaping step. 
     Due in part to the remaining production steps, accommodation of any changes in size (e.g., expansion, contraction, etc.) that may occur or are likely to occur to the implants can be considered during manufacturing by properly sizing and otherwise designing the mold. The amount of contraction or expansion of the implant can be based on one or more factors or conditions, such as, for example, the number of freeze/thaw cycles to which the implant is subjected, the temperature and/or pressure ranges associated with the remaining steps, and/or the like. 
     In some embodiments, the implant can be formed, at least in part, using an injection molding process and/or any other molding or casting procedure. In such injection or transfer molding techniques, once the hydrogel or other implant solution has been prepared, the solution can be loaded into an injection cylinder or other container of a molding press. The solution can then be forcibly transferred into a closed mold assembly using a pneumatic or hydraulic ram or any other electromechanical device, system, and/or method. In some embodiments, the hydrogel and/or other solution or implant component is injected into a corresponding closed mold assembly through a standard runner and gate system. Injection molding of implants can provide one or more benefits relative to open mold assemblies. For example, an implant formed using an injection molding technique may be substantially free of or free of additional cutting, reshaping, resizing, and/or processing, due to being in essentially a final shape after completion of injection molding. 
     Regardless of how the implant is molded or otherwise shaped or manufactured, the implant can be subsequently subjected to one or more freeze/thaw cycles, as desired or required. In some embodiments, an implant in a mold cavity is cooled using a total of four freeze/thaw cycles in which the temperature is sequentially varied between about −20° C. and about 20° C. In some embodiments, the number of freeze/thaw cycles, the temperature fluctuation, and/or other details can be different than disclosed herein, in accordance with a specific production protocol and/or implant design. 
     Following freeze/thaw cycling, the implant can be at least partially removed (e.g., including fully removed) from the mold and placed in one or more saline and/or other fluid (e.g., other liquid) baths where the implant can be subjected to additional cooling and/or other treatment procedures (e.g., to further stabilize the physical properties of the implant). In some embodiments, the implant undergoes an additional eight freeze/thaw cycles while in saline. In some embodiments, such follow-up cooling procedures can be either different (e.g., more or fewer freeze/thaw cycles, different type of bath, etc.) or altogether eliminated from the production process, as desired or required. 
     When the cooling (e.g., freeze/thaw cycling) and/or other manufacturing processes have been completed, the implants can be inspected for any manufacturing flaws or other defects. At least some of the implants can be subjected to selective testing for physical and other characteristics, in accordance with the original design goals and/or target parameters. The implant may be cut or otherwise processed to remove any excess portions (e.g., flash). In some embodiments, one or more completed implant(s) is packaged in hermetically sealed plastic trays or other containers comprising foil or other types of lids or covering members. A volume of saline and/or other liquid can be included within such trays or other containers to provide hydration of the implant(s) during storage and/or any other steps preceding use. In some embodiments, the implant tray or other container is terminally sterilized using e-beam exposure between about 25 kilogray (kGy) and about 40 kGy. 
     Additional details related to implants comprising hydrogels, including methods of manufacturing and use, can be found in U.S. Pat. Nos. 5,981,826, 6,231,605, and PCT Patent Application Publication No. WO 2012/162552, each of which is hereby incorporated by reference in its entirety for all purposes. 
     In some embodiments, the implant  100  has a lateral dimension (e.g., diameter) between about 4 mm and about 8 mm (e.g., about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, ranges between such values, etc.), as measured in an uncompressed state. Lateral dimensions smaller than about 4 mm (e.g., between about 2 mm and about 4 mm) and larger than about 8 mm (e.g., between about 8 mm and about 10 mm) are also possible for use in subjects with small or large bones, respectively. 
     In some embodiments, the implant  100  comprises, or alternatively consists essentially of, or alternatively consists of, a top or upper surface  102 , a bottom or lower surface  104  generally opposite the upper surface  102 , and a hydrogel body between the upper surface  102  and the lower surface  104 . In some embodiments, the implant  100  comprises a hydrogel (e.g., PVA) implant  100  or any other type of substrate-based implant  100 . In some embodiments, the implant  100  is capable of being used and/or is configured to be used in a joint treatment method as disclosed herein, modifications thereof, and/or other methods. In some embodiments, sidewalls  106  generally extend between the upper surface  102  and the lower surface  104 . In some embodiments, the implant  100  is configured for placement in an implant site having a corresponding recess. 
     In some embodiments, the overall height (e.g., between the top surface  102  and the bottom surface  104 ) of the implant  100  is between about 4 mm and about 8 mm (e.g., about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, ranges between such values, etc.), as measured in an uncompressed state. Heights smaller than about 4 mm (e.g., between about 2 mm and about 4 mm) and larger than about 8 mm (e.g., between about 8 mm and about 10 mm) are also possible for use in subjects with small or large bones, respectively. 
     The upper surface  102  may be configured to form an articulation surface when the implant  100  is implanted in a joint. As shown, the upper surface  102  can comprise a contour configured to correspond to contours of a lower surface of a first metacarpal bone (facing the trapezium) and/or an upper surface of a trapezium (facing the first metacarpal bone). In some embodiments, the upper surface  102  has a saddle shape comprising peaks  118   a ,  118   b  and troughs  120   a ,  120   b . The contours of the upper surface  102  are illustrated by line contours in  FIG. 1C . The contours of the upper surface  102  of the implant  100  may be modified to match a specific anatomy (e.g., a surface (e.g., inferior surface) of a trapezium). In some embodiments, a surface of a bone (e.g., first metacarpal bone) and/or an opposing bone (e.g., trapezium) may be scanned (e.g., via computerized tomography (CT), computerized axial tomography (CAT), positron emission tomography (PET), magnetic resonance imaging (MRI), combinations thereof, etc.), which can be used to make a mold (e.g., via 3D printing, CAD-CAM milling, etc.) to match specific anatomical features of a specific patient or subject, which can be advantageous, for example, when the anatomy has been damaged or otherwise includes unique characteristics. 
     The upper surface  102  comprises, or alternatively consists essentially of, or alternatively consists of, a saddle shape including a first peak  118   a , a second peak  118   b , a first trough  120   a  laterally between the first peak  118   a  and the second peak  118   b , and a second trough  120   b  laterally between the first peak  118   a  and the second peak  118   b . The first peak  118   a  is laterally between the first trough  120   a  and the second trough  120   b . The second peak  118   b  is laterally between the first trough  120   a  and the second trough  120   b . In some embodiments, a distance between the first peak  118   a  and/or the second peak  118   b  and the lower surface  104  is between about 10% and about 20% greater than a distance between at least one of the first trough  120   a  and the second trough  120   b  and the lower surface  104 . One or both of the peaks  118   a ,  118   b  may be between about 1 mm and about 1.5 mm (e.g., about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, ranges between such values, etc.) higher than one or both of the troughs  120   a ,  120   b.    
     Although the implant  100  is illustrated as a substantially cylindrical plug or shape, other shapes of the implant  100  are also possible. For example, an upper surface  102  and/or the lower surface  104  may be contoured to abut particular anatomy (e.g., planar (e.g., flat), non-planar (e.g., curved, concave, convex, undulating, fluted)) and/or modified anatomy (e.g., a recess formed in a bone). The implant  100  can include a generally circular or oval cross-sectional shape. In some embodiments, the implant  100  is generally shaped like a cylinder. The overall shape of any of the implants disclosed herein can vary depending on the specific application or use. For example, the shape of at least part of the implant  100  can be generally polygonal (e.g., rectangular, round, hexagonal), irregular, and/or the like. 
     In some embodiments, the implant  100  lacks, is devoid of, is substantially free of, etc. attachment tabs or other features configured to fix the implant  100  in place. For example, the implant  100  may maintain position by being slightly oversized with respect to a cavity in which a portion of the implant  100  is positioned. 
     In some embodiments, the implant  100  lacks, is devoid of, is substantially free of, etc. surface contours on the bottom surface  104 . For example, the implant  100  may lack configuration to be placed between a first metacarpal bone and a trapezium without forming a cavity in the first metacarpal bone. 
     In some embodiments, the implant  100  lacks, is devoid of, is substantially free of, etc. an upper surface  102  configured to replace a bone or an end of a bone. For example, the implant  100  may be configured to replace part of an end surface of a bone (e.g., a central portion, a bearing surface, etc.), but not to replace the entire bone and/or the end surface. 
       FIGS. 2A-5B  illustrate example tooling or systems that may be used to deploy the implant  100  in a carpometacarpal joint such as between the first metacarpal bone and the trapezium. The implant  100  or variations thereof may also be used at other joints. In some embodiments, a plurality of implants (e.g., the implant  100 ) may be used in a carpometacarpal joint or other joints. In certain instances, reference is made to  FIGS. 6A-6Z  to illustrate or explain an aspect, potential advantage, etc. of a tool or system. One or more of the tools can be used in combination with a substantially cylindrical, elongate guide pin having a sharpened end (or another guiding device), which can aid in alignment of the tools throughout a treatment method. In some embodiments in which an implant comprises a bone anchor, the bone anchor may fit in a hole created by the guide pin. Absence of a guide pin or other guiding device is also possible. 
       FIGS. 2A-3D  illustrate example components of a system, for example, usable to create a cavity into which the implant  100  may be inserted. The introducer placer  200  of FIGS.  2 A- 2 C may be used in combination with a drill bit or other system different than the drill bit  300  of  FIGS. 3A-3D . The drill bit  300  of  FIGS. 3A-3D  may be used in combination with a placer or other system different than the placer  200  of  FIGS. 2A-2C . Other systems and methods for creating a cavity are also possible, including modifications to the placer  200  and/or the drill bit  300 . The spacer  200  and/or drill bit  300  may be used in combination with the introducer  400  of  FIGS. 4A and 4B , other introducers, the plunger  500  of  FIGS. 5A and 5B , other plungers, or other systems. 
       FIG. 2A  is a side perspective view of an example placer  200 . The placer  200  comprises a first end  202 , a second end  204  generally opposite the first end  202 , and a body  206  extending between the first end  202  and the second end  204 . The body  206  is generally cylindrical, although other shapes are also possible (e.g., having an elliptical cross-section, having a polygonal cross-section, etc.). The placer  200  can comprise stainless steel (e.g., surgical grade stainless steel), plastic, combinations thereof, and/or the like. 
       FIG. 2B  is a first end  202  and side perspective view of the placer  200  of  FIG. 2A . In some embodiments, the first end  202  has a saddle shape comprising peaks  218   a ,  218   b  and troughs  220   a ,  220   b . The contours of the first end  202  are illustrated by line contours in  FIG. 2B . The contours of the first end  202  may be modified to match a specific anatomy (e.g., a surface (e.g., inferior surface) of a trapezium) and/or anatomy of a specific patient or subject (e.g., using scanning and manufacturing process as described herein). In certain such embodiments, the first end  202  of the placer  200  may be exchangeable (e.g., using a first end  202  configured to engage a standard body  206  using threads or other attachment mechanism). In some embodiments, the first end  202  is substantially flat or planar. 
       FIG. 2C  is a second end  204  and side perspective view of the placer  200  of  FIG. 2A . In some embodiments, the second end  204  is substantially flat or planar. In some embodiments, the second end  204  has a shape configured to correspond to a shape created by a certain drill bit. In certain such embodiments, the second end  204  of the placer  200  may be exchangeable (e.g., using a second end  204  configured to engage a standard body  206  using threads or other attachment mechanism). The body  206  may comprise a substantially cylindrical body having threads or other coupling mechanisms at one or both ends for coupling to a modular first end  202  (e.g., for different anatomies) and/or a modular second end  204  (e.g., for different drill bits). The threads or other coupling mechanisms at one or both ends may be the same (e.g., to allow either side of the body  206  to be used for the first end  202  or the second end  204 ) or different (e.g., to inhibit or prevent use of different sides of the body  206  for the same ends  202 ,  204 ). 
     In some embodiments, the placer  200  includes a lumen  208  in the body  206  between the first end  202  and the second end  204 . The lumen  208  is configured to accept a guide pin therethrough, for example as described with respect to  FIG. 6E . The lumen  208  may be centered in the body  206  or may be radially offset. In some embodiments, the body  206  comprises a plurality of lumens (e.g., allowing a user to select a lumen based on the interaction of the first end  202  of the spacer  200  with the anatomy). In some embodiments, the drill bit  300  can be advanced to the targeted drill site of the patient bone or other anatomical location with the assistance of a guide pin or other guiding device or member. A cannulated drill bit  300 , as discussed herein, can be passed over the guide pin to ensure that the distal, working end  302  of the drill bit  300  is properly positioned relative to the treatment site (e.g., bone, joint). 
     The placer  200  may comprise, for example proximate to the second end  204 , a plurality of arcuate bands  210   a ,  210   b ,  210   c ,  210   d ,  210   e  that can be used to measure depth of a cavity, for example a cavity resulting from drilling into bone. In some embodiments, the band  210   a  may correspond to a depth from the second end  204  of about 6 mm, the band  210   a  may correspond to a depth from the second end  204  of about 6 mm, the band  210   b  may correspond to a depth from the second end  204  of about 7 mm, the band  210   c  may correspond to a depth from the second end  204  of about 8 mm, the band  210   d  may correspond to a depth from the second end  204  of about 9 mm, and the band  210   e  may correspond to a depth from the second end  204  of about 10 mm, the bands  210   a ,  210   b ,  210   c ,  210   d ,  210   e  being spaced by about 1 mm. The bands  210   a ,  210   b ,  210   c ,  210   d ,  210   e  may be spaced by about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, about 1 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, about 2 mm, greater than about 2 mm, combinations thereof, and the like. The plurality of bands may comprise between four bands and six bands (e.g., four, five, six, ranges between such values, etc.). More bands (e.g., between six bands and ten bands) or fewer bands (e.g., between one band and four bands) are also possible. For example, the bands may start closer to the second end  204  (e.g., about 0.1 mm, about 0.5 mm, about 1 mm, etc. from the second end  204 ). The bands may be fully arcuate (e.g., extending around part of the circumference of the body  206 ) and/or partially arcuate (e.g., extending around part of the circumference of the body  206 ). The bands may each be the same or may be different from each other. The bands may be used to measure a depth of a drilled hole in a bone, for example as described in further detail with respect to  FIG. 6K . In some embodiments, the bands may comprise distinguishing indicia. For example, the bands may comprise different dash patterns (e.g., a dotted band  210   a , a solid band  210   b , a dashed band  210   c , a solid band  210   d , and a dotted band  210   e ), different colors (e.g., different colors in the color palette, different shades, etc.), numbers (e.g., indicative of depth, band number, etc.), combinations thereof, and the like. 
     The placer  200  may comprise the features described herein with respect to one or both of the first end  202  (e.g., a saddle shape) and the second end  204  (e.g., measurement bands). In some embodiments, a first tool can include the features of the first end  202  and a second, separate, tool can include the features of the second end  204 . 
       FIG. 3A  is a side and bottom perspective view of an example drill bit  300 .  FIG. 3B  is a side perspective view of the drill bit  300  of  FIG. 3A .  FIG. 3C  is a bottom plan view of the drill bit  300  of  FIG. 3A .  FIG. 3D  is a top and side perspective view of the drill bit  300  of  FIG. 3A . The drill bit  300  can be used to create a recess or hole or cavity or aperture or crater or pit or pocket in a bone, for example in which an implant  100  can be placed. The drill bit  300  comprises, or alternatively consists essentially of, a distal end  302 , a proximal end  304  generally opposite the distal end  302 , and a body  306  extending between the distal end  302  and the proximal end  304 . The drill bit  300  may comprise, for example, stainless steel. 
     In some embodiments, the body  306  of the drill bit  300  includes a generally cylindrical distal section  306   a  and a polygonal proximal section  306   b . The cylindrical distal section  306   a  may provide strength to the drill bit  300  and/or reduce eccentricity during drill rotation. The polygonal proximal section  306   b  is sized, shaped, and otherwise configured to selectively mate with a corresponding portion of a bone drill (not shown). In some arrangements, the proximal section  306   b  comprises a generally triangular cross-sectional area, but other shapes, sizes, and/or other details of the proximal section  306   b  can vary. Other shapes of the body  306 , including the distal section  306   a  and/or the proximal section  306   b , are also possible. Bone drills with which the drill bit  300  or variations thereof can be coupled may be manually operated and/or power driven (e.g., mechanically, pneumatically, hydraulically, etc.). 
     The distal end  302  of the drill bit  300  can include a flange  312  and one or more abrading members or blades or cutters  310   a ,  310   b ,  310   c  extending distally from the flange  312 . As best illustrated in  FIG. 3C , the drill bit  300  can comprise a total of three cutters  310   a ,  310   b ,  310   c  that are generally equally spaced apart (e.g., at angles of approximately 120° relative to each other). The quantity, size, shape, position, orientation, spacing, and/or other characteristics or properties of the cutters  310  can vary. For example, a drill bit can include more than three cutters or fewer than three cutters (e.g., 1, 2, 4, 5, more than 5, etc.), as desired or required. For another example, a drill bit can include cutters that are larger and/or smaller, that extend along different portions of the distal end of the drill bit, combinations thereof, and the like. The flange  312  can provide a non-cutting “stop” surface that can inhibit the drill bit  300  from cutting below a certain depth, even if further rotation and pressure are applied. The flange  312  can aid in removal of cut material, for example inhibiting or preventing cut material from spraying past the flange unabated. 
     In some embodiments, the drill bit  300  comprises a lumen  308  extending (e.g., longitudinally) through the drill bit  300 . For example, as illustrated in  FIGS. 3A and 3D , the lumen  308  can generally extend from the distal end  302  to the proximal end  304 . As described herein, a lumen  308  can help ensure that the drill bit  300  is accurately positioned relative to a joint, bone, and/or other portion of anatomy of a subject (e.g., over a guide pin) before commencing and/or during a drilling procedure. 
     As the drill bit  300  is rotated (e.g., either manually or using one or more external driving sources, etc.), sharp edges formed along the distal and/or peripheral portions of the cutters  310   a ,  310   b ,  310   c  can abrade and remove cartilage, bone, and/or other tissue. In some embodiments, the longitudinal distance between the distal face of the flange  312  and the distal ends of the cutters  310   a ,  310   b ,  310   c  can limit the depth of the recess or opening that is created by the drill bit  300 . Peripheral surfaces of the cutters  310   a ,  310   b ,  310   c  can define a diameter φ c  ( FIG. 3C ) or other cross-sectional dimension that can limit the diameter of the resulting recess or other openings that is created by the drill bit  300 . Peripheral surfaces of the flange  312  can define a diameter φ f  ( FIG. 3C ) greater than φ c  or other cross-sectional dimension that can limit the depth of the resulting recess or other openings that is created by the drill bit  300 . The drill bit  300  can thereby be configured to create an implant site having specific dimensions (e.g., depth, diameter, etc.). In some embodiments, drill bits of varying size and shape are available to the surgeon or other clinician in order to accurately create a specific desired implant site. For any of the embodiments disclosed herein, the distal edges and/or other surfaces of the cutting blades or cutters can be generally flat and/or otherwise contoured (e.g., to generally match and/or receive the base of the implant). 
     As the drill bit  300  is rotated and advanced into a targeted region of the patient&#39;s anatomy, abraded bone, cartilage and/or other tissue, and/or other debris is created at or near the distal end  302 . To permit such debris to be removed from the treatment site, the flange  312  can include one or more openings, for example in the form of through holes, channels, edge features, etc. Abraded materials can stay clear of and not interfere with the working end of the drill bit  300 , allowing the cutters  310   a ,  310   b ,  310   c  to continue to function normally. Once the distal face of the flange  312  abuts the top surface of the bone being drilled, further advancement of the drill bit  300  can be inhibited or prevented. Resistance to further advancement can alert the clinician that an implant site having the desired depth and diameter has been properly created. 
     The cutters  310   a ,  310   b ,  310   c  can be joined along a hub  314  along or near the center of the distal face of the flange  312 . As shown, the cutters  310   a ,  310   b ,  310   c  can extend at least radially outwardly from the hub  314 , toward the outer periphery of the flange  312 . The radial length of the cutters  310   a ,  310   b ,  310   c  can help determine a diameter of a recess or opening created by the drill bit  300 . In embodiments in which peripheral edges of the cutters  310   a ,  310   b ,  310   c  are generally vertically oriented (e.g., as illustrated in  FIG. 3B ), the corresponding opening created by the drill bit  300  is generally cylindrical. In some embodiments, the cutters can extend distally from a distal-facing surface, such as the distal-facing surface of the flange  312 , without a hub  314 . 
       FIGS. 4A-5B  illustrate example components of a deployment system or delivery device, for example usable to deploy the implant  100 . The introducer  400  of  FIGS. 4A and 4B  may be used in combination with a plunger or other system different than the plunger  500  of  FIGS. 5A and 5B . The plunger  500  of  FIGS. 5A and 5B  may be used in combination with an introducer or other system different than the introducer  400  of  FIGS. 4A and 4B . Other systems and methods for deploying or delivering an implant are also possible, including modifications to the introducer  400  and/or the plunger  500 . The introducer  400  and/or plunger  500  may be used in combination with the placer  200  of  FIGS. 2A-2C , other placers, the drill bit  300  of  FIGS. 3A-3D , other placers, or other systems. 
       FIG. 4A  is a side and bottom perspective view of one embodiment of an introducer  400 . The introducer  400  can comprise, or alternatively consist essentially of, a distal end  402 , a proximal end  404  generally opposite the distal end  402 , and a generally cylindrical tube  406  having an opening or lumen  408  through which an implant (e.g., the implant  100 ) may be passed. In some embodiments, the distal end  402  of the introducer  400  comprises a neck portion or other narrowed portion  410 . The neck portion  410  is configured to be positioned at least partially in a recess created by a drill bit and in which an implant will be at least partially secured. In some embodiments, the introducer  400  is sized, shaped, and otherwise configured to that the neck portion  410  fits generally snugly within the implant site. The shoulder  412  or other feature where the introducer  400  returns to the normal or nominal or larger diameter can act as a depth stop, which can ensure that the implant is positioned in the recess. In some embodiments, the shoulder  412  can help protect the structural integrity of the implant as the implant is being deployed. In some embodiments, the shoulder  412  comprises a distally-facing surface that is substantially flat or planar (e.g., as illustrated in  FIG. 4A ). In some embodiments, the shoulder  412  comprises a distally-facing surface that is contoured (e.g., to correspond to an undrilled surface of a first metacarpal bone). The body  406  may comprise a substantially cylindrical body having threads or other coupling mechanisms for coupling to a modular distal end  402  (e.g., for different anatomies). 
       FIG. 4B  is a side and top perspective view of the introducer  400  of  FIG. 4A . The internal diameter of the introducer  400  can vary along its longitudinal length. For example, as shown in  FIG. 4B , the proximal end  404  of the introducer  400  comprises, at least partially, a flared shape  414  in which at least a portion of the inside diameter of the lumen  408  is progressively reduced in the proximal to distal direction. The lumen  408  can maintain a generally constant inner diameter distal to the flared shape  414  forming a generally cylindrical interior portion. The lumen  408  can have a diameter that his smaller than a diameter of an uncompressed implant such that the implant is radially inwardly compressed as the implant is distally advanced through the flared shape  414 . In some embodiments, compression of the implant may aid in deployment of the implant by allowing the compressed implant to be positioned in a recess in bone having a smaller diameter than a diameter of the uncompressed implant, which can allow the implant to radially outwardly expand to provide apposition against sidewalls of the recess. In some embodiments, compression of the implant may inhibit the implant from falling out of the introducer  400  during deployment (e.g., due to apposition of the implant against sidewalls of the lumen  408 ). 
     In some embodiments, the introducer  400  comprises alignment indicia  416  configured to align an implant having a contoured surface (e.g., a contoured upper surface) before and/or during deployment. As described with respect to  FIGS. 60-6T , the trough  120   a  or  120   b  of an implant  100  having a saddle shape may be aligned with the indicia  416  at the proximal end  404  of the introducer  400 . The indicia  416  may include pictures or other terms indicative of what should be aligned (e.g., a trough shape as shown in  FIG. 4A , the term “trough,” combinations thereof, and the like). As described with respect to  FIGS. 6U-6X , the trough  20   a  or  20   b  of a bone surface having a saddle shape may be aligned with the indicia  416  at the distal end  402  of the introducer  400 . In some embodiments, compression of the implant can inhibit or prevent rotation of the implant in the introducer  400  such that alignment at the proximal end  404  can provide alignment at the distal end  402 . In some embodiments, the peak  118   a  or  118   b  of an implant  100  having a saddle shape may be aligned with the indicia  416 . In some embodiments in which the implant has a non-circular lateral cross-section (e.g., elliptical, polygonal, etc.), the lumen  408  may have a corresponding lateral cross-section, which can inhibit or prevent rotation of the implant in the introducer  400  such that alignment at the proximal end  404  can provide alignment at the distal end  402 . 
     In some embodiments, the introducer  400  comprises a viewing window that permits an implant to be viewed as it is advanced through the introducer  400 , for example prior to and/or during deployment. The viewing window can be separate or integrated as part of the alignment indicia  416 . For example, the alignment indicia  416  may comprise ink, etching, and/or windows (e.g., comprising unfilled slits and/or a biologically compatible non-opaque or at least partially optically transparent material). 
     In some embodiments, the inner diameter, length, other dimension, and/or other details or properties of the introducer  400 , including a flared shape  414 , a generally cylindrical interior portion, a neck portion  410 , and/or the like can be different than shown and described herein. For example, the flared shape  414  can extend along more, or even all or substantially all, of the length of the lumen  408 . For another example, the interior surface of the body  406  may be at least partially non-linear (e.g., curved, rounded, irregular, etc.), in addition to or in lieu of any generally linear and/or constant portions, as desired or required. 
     In some embodiments, the longitudinal axis of the introducer  400  (and the longitudinal axis along which the implant is advanced through the introducer  400 ) is substantially perpendicular or perpendicular with or at another desired angle to the surface of the bone or other anatomical site (e.g., bottom of the recess) into which the implant will be delivered and/or the distal end  402  or a portion thereof is substantially parallel or parallel to a longitudinal axis of the bone or other anatomical structure (e.g., longitudinal axis of the recess). 
     In some embodiments, at least a portion of the interior of the introducer  400  comprises and/or is coated or lined with one or more absorbable or lubricious layers, materials, and/or other substances. Such materials can help preserve a moisture level of the implant during deployment. The interior surface of the introducer  400  can comprise a low coefficient of friction to facilitate the delivery of an implant through the lumen  408 . In some embodiments, reducing an effective coefficient of friction along the interior of the introducer  400  can comprise polishing the interior surfaces of the introducer  400 . The introducer  400 , including interior surfaces, can comprise stainless steel (e.g., surgical grade stainless steel), titanium, other metals and/or alloys, plastic, combinations thereof, and/or the like. 
       FIG. 5A  is a side and bottom perspective view of an example plunger  500 .  FIG. 5B  is a side perspective view of the plunger  500  of  FIG. 5A . The plunger  500  may be used in combination with the introducer  400  to form a deployment system. The plunger  500  comprises, or alternatively consists essentially of, a distal end  502 , a proximal end  504  generally opposite the distal end  502 , and a body  506  between the distal end  502  and the proximal end  504 . 
     The distal end  502  has a saddle shape comprising peaks  518   a ,  518   b  and troughs  520   a ,  520   b . The contours of the distal end  502  are of the plunger  500  may be modified to match a specific anatomy (e.g., a surface (e.g., inferior surface) of a trapezium). The body  506  may comprise a substantially cylindrical body having threads or other coupling mechanisms for coupling to a modular distal end  502  (e.g., for different anatomies). In some embodiments, a modular distal end can be used as the distal end  202  of the spacer  200  and the distal end  502  of the plunger  500 . As described with respect to  FIGS. 6Q-6T , the peaks  118   a ,  118   b  and troughs  120   a ,  120   b  of an implant  100  having a saddle shape may be aligned with the peaks  518   a ,  518   b  and troughs  520   a ,  520   b  of the distal end  502  of the plunger  500 . Although the fit of the implant in the introducer  400  may inhibit or prevent rotation, a properly seated plunger  500  (e.g., with the contours of the distal end  502  aligned with the contours of an implant) can be used to check for rotation. For example, as described with respect to  FIG. 6V , the plunger proximal end  504  of the plunger may comprise indicia  516 . The indicia  516  may include pictures or other terms indicative of what should be aligned (e.g., a trough shape as shown in  FIGS. 5A and 5B , the term “trough,” combinations thereof, and the like). In some embodiments, if the indicia  516  are aligned with the indicia  416  at the proximal end  404  of the introducer  400  (e.g., as shown in  FIG. 6T ) and the plunger  500  is properly seated, then the implant can be expected to be aligned with the indicia  416  of the introducer  400 . If the introducer  400  is properly seated (e.g., with the indicia  416  aligned with the peaks and/or troughs of a bone), then the implant should be properly aligned upon deployment. In some embodiments, the proximal end  504  (e.g., the radially outward extending arms of a T-shape) may be used as indicia  516 . 
     The proximal end  504  of the plunger  500  may comprise an enlarged head portion  512 . In some embodiments, the head portion  512  is in a T-shape (e.g., as illustrated in  FIGS. 5A and 5B ). In some embodiments, the head portion  512  comprises a ball, a flat surface, a handle, a grasping portion configured to be selectively gripped and manipulated, or any other surface suitable for engagement by a hand. In some embodiments, the head portion  512  is configured to engage an external power-assist device (e.g., mechanically, pneumatically, hydraulically, etc.), as desired or required. The body  506  may comprise a substantially cylindrical body having threads or other coupling mechanisms for coupling to a modular proximal end  504  (e.g., for user preference of a manual handle, for optional connection to a power-assist device). 
     In some embodiments, the body  506  may be the same as the body  206 , and modular first or distal ends  202 ,  502  and/or second or proximal ends  204 ,  504  may be coupled for use as a spacer or a head portion. For example, a body can be coupled to a modular distal end and first modular proximal end for use as a spacer, after which the first modular proximal end can be exchanged with a second modular proximal end for use as a plunger. The bands for a spacer and the indicia for a plunger may be integrated with each other on the body, the bands may be part of a modular proximal end, and/or the indicia may be part of a modular distal end. Such embodiments can reduce costs (e.g., because the same body is used for the spacer and the plunger and/or provide better alignment (e.g., because the same modular distal end is used to guide the drill bit and to deploy the implant). If the modular distal end of the plunger does not correspond to the proximal end of the implant, that could indicate a problem with the modular distal end and/or the implant, which could inhibit or prevent placement of improper implants that may be difficult to remove once deployed. 
     In some embodiments, the plunger  500  includes a motion limiter or depth stop. The motion limiter can comprise one or more knobs, protrusion members, and/or other features that generally extend outwardly from the body  506  and/or the head portion  512 . In some embodiments, a motion limiter is configured to slide in a portion of the lumen  408  of the introducer  400  (e.g., in the flared shape  414  but not distal thereto). A motion limiter can help inhibit or prevent distal movement of the plunger  500  relative to the introducer  400  (e.g., when the motion limiter contacts or abuts a surface of the introducer  400 ). A motion limited can help inhibit or prevent rotation of the plunger  500  relative to the introducer  400  during use, which can aid in proper alignment and positioning of the implant during deployment. 
     The body  506  of the plunger  500  can comprise a generally cylindrical shape configured to fit through the lumen  408  of the introducer  400  (e.g., including distal to the flared shape  414 ). The body  506  can have a lateral dimension (e.g., diameter) that is slightly smaller than a smallest lateral dimension (e.g., diameter) of the lumen  408  of the introducer  400 . As discussed in greater detail herein, by actuating the deployment device, a clinician, surgeon, or other user can selectively move the plunger  500  within an interior portion of the introducer  400  in order to urge an implant (e.g., the implant  100 ) through the distal end  402  of the introducer  400  and in a targeted implant site. Other shapes of the body  506  are also possible (e.g., having an elliptical cross-section, having a polygonal cross-section, etc.). The body  506  may be hollow (e.g., to reduce weight or material used, if the same as the body  206 ), solid (e.g., to increase strength or rigidity), and the like. 
     In some embodiments, the deployment system or delivery device comprises and/or is operatively coupled to one or more pressure gauges or other pressure or force measuring devices, members, and/or features. Such gauges or other measurement devices can help ensure that a certain (e.g., maximum or threshold) backpressure or force is not exceeded when operating the device, which can help protect the integrity of an implant being deployed (e.g., to maintain the structural integrity, water composition, and/or other properties of the implant), protect the delivery device, protect the user and/or the subject, and/or provide one or more other advantages or benefits. 
     The components of the delivery device can comprise one or more rigid and/or semi-rigid materials configured to withstand the forces, moments, chemicals, and/or other substances, temperature fluctuations, and/or other elements to which they may be exposed. For example, the components of the implant delivery device can comprise one or more metals (e.g., stainless steel, surgical stainless steel, other types of steel, etc.), alloys, plastics, combinations thereof, and/or the like. Such materials can permit the device to be autoclaved, sterilized, or otherwise cleaned during a specific disinfection protocol. The structural and other physical characteristics of the device can permit the user to exert appropriate forces to deliver implants of various sizes, shapes, and/or configurations through the introducer and in a target implant site of a subject. 
     In some embodiments, a kit comprises at least two of the placer, drill bit, introducer, plunger, and guide pin. For example, the kit may comprise the placer and drill bit; the placer and introducer; the placer and plunger; the placer and guide pin; the placer, drill bit, and introducer; the placer, drill bit, and plunger; the placer, drill bit, and guide pin; the placer, drill bit, introducer, and plunger; the placer, drill bit, introducer, and guide pin; the placer, drill bit, plunger, and guide pin; the drill bit and introducer; the drill bit and plunger; the drill bit and guide pin; the drill bit, introducer, and plunger; the drill bit, introducer, and guide pin; the drill bit, plunger, and guide pin; the drill bit, introducer, plunger, and guide pin; the introducer and plunger; the introducer and guide pin; the introducer, plunger, and guide pin; the plunger and guide pin; the placer, drill bit, introducer, plunger, and guide pin; and any other permutations of tools described herein, modifications thereof, and the like. In certain such embodiments, the kit may comprise the implant or a plurality of implants (e.g., having different dimensions). The kit may comprise a packaging in which the components are sterilized. 
     In some embodiments, the kit comprises at least two of means for placing an implant (e.g., the placer), means for forming a cavity (e.g., the drill bit), and means for deploying an implant (e.g., comprising the introducer and/or the plunger). In some embodiments, the kit further comprises means for treating a joint (e.g., the implant). 
     In some embodiments, the kit comprises a body having a proximal end and a distal end. The distal end of the body comprises a coupling feature (e.g., threads). The kit further comprises at least one modular distal end comprising a coupling feature (e.g., threads) complementary to the coupling feature of the distal end of the body. In some embodiments, a distal surface of the modular distal end comprises a saddle shape configured to correspond to a surface of an implant. The proximal end of the body comprises a coupling feature (e.g., threads). The kit further comprises at least one modular proximal end comprising a coupling feature (e.g., threads) complementary to the coupling feature of the proximal end of the body. In some embodiments, the kit comprises a plurality of modular proximal ends. For example, a first modular proximal end may comprise a substantially flat surface and depth bands and a second modular proximal end may comprise a T-shaped handle and implant alignment indicia. 
       FIGS. 6A-6Z  schematically illustrate an example method of positioning an example carpometacarpal implant  100 . Although illustrated with reference to the implant  100 , the placer  200 , the drill bit  300 , the introducer  400 , and the plunger  500 , as described above in detail, other implants, tools, systems, and methods are possible. Although illustrated as positioning the implant  100  in a right hand, positioning in the left hand is also possible. 
     In  FIG. 6A , an incision  14  is made proximate to (e.g., close enough to sufficiently access) the joint between the trapezium  10  and the first metacarpal bone  12 . The cartilage between the trapezium  10  and the first metacarpal bone  12  has been worn out or damaged. Additional steps and/or other actions associated with a procedure, such, as, for example, sterilization, anesthesia, site preparation, and the like, may be used; however, details have been omitted from the description of the procedure herein for brevity. 
     As shown in  FIG. 6B , the thumb including the first metacarpal bone  12  can be bent (e.g., downwardly) to expose the joint between the trapezium  10  and the first metacarpal bone  12 , including an end surface  16  of the first metacarpal bone  12 . Skin, muscle, ligaments, etc. are omitted from  FIGS. 6B-6M and 6U-6Z  for clarity. The end surface  16  has a generally concave saddle shape including peaks  18   a ,  18   b  and troughs  20   a ,  20   b . Surfaces of the implant  100 , the placer  200 , the introducer  400 , and/or the plunger  500  may be contoured to correspond to a surface of one or more others of the implant  100 , the placer  200 , the introducer  400 , and/or the plunger  500 , a surface of a metacarpal bone, and/or a surface of a trapezium. 
     In  FIGS. 6C and 6D , a placer  200  is advanced toward the end surface  16  through the incision  14  ( FIG. 6A ). The placer  200  may be generally longitudinally aligned with the first metacarpal bone  12 . In  FIG. 6D , the first end  202  of the placer  200  abuts the end surface  16 . 
     In some embodiments, a guide pin  22  is advanced through the lumen  208  of the placer  200  and positioned in or “tamped” at least partially in the first metacarpal bone  16 .  FIG. 6E  shows the guide pin  22  placed using the placer  200 . Placement of the guide pin  22  without a placer is also possible. The guide pin  22  may be substantially parallel or parallel with a longitudinal axis of the first metacarpal bone  16 , at an angle (e.g., about 90°, less than about 90°, greater than about 90°) to the end surface  16  or a portion (e.g., a certain contour) thereof. The guide pin  22  may be advanced through the anatomy using a trocar or similar device. 
       FIGS. 6F-6I  illustrate the drill bit  300  forming a cavity or recess or hole or aperture or crater or pit or pocket  24  in the first metacarpal bone  12 .  FIG. 6F  shows the drill bit  300  being tracked over the guide pin  22  towards the end surface  16  of the first metacarpal bone  12 . The guide pin  22  can help ensure that the drill bit  300  is properly positioned relative to the treatment site (e.g., joint). Forming the cavity  24  without a guide pin  22  is also possible.  FIG. 6G  shows the inception of formation of the cavity  24  due to rotation about the longitudinal axis of the drill bit  300  and distal longitudinal advancement towards the end surface  16 . In the embodiment of  FIG. 6H , the flange  312  abuts the end surface  16 , which inhibits or prevents further drilling by the drill bit  300 .  FIG. 61  shows the drill bit  300  being proximally retracted over the guide pin  22  after forming the cavity  24 . The cavity  24  has a diameter and depth based on the configuration of the drill bit  300  (e.g., dimensions of the cutters  310   a ,  310   b ,  310   c , the flange  312 , etc.). 
     In some embodiments, the lateral dimension (e.g., diameter) of the cavity  24  is smaller than the lateral dimension (e.g., diameter) of the implant  100 , which may flex radially inwardly. Although illustrated as a cylindrical hole  24 , other shapes are also possible (e.g., trapezoidal tapering inwards towards the upper surface). In some embodiments, a lateral dimension and/or cross-sectional area of the cavity  24  is about 5% to about 15% (e.g., about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, ranges between such values, etc.) narrower or otherwise smaller than the lateral dimension and/or cross-sectional area of the implant  100 . The cavity  24  may be coated or otherwise treated prior to positioning of the implant  100 . 
       FIGS. 6F-6I  illustrate the placer  200  being used to measure and/or check depth of the cavity  24 . In  FIG. 6J , the placer  200  has been flipped so the second end  204  faces the cavity  24 . In some embodiments, a separate tool is used. The placer  200  is tracked over the guide pin  22  towards and, as shown in  FIG. 6K , partially into the cavity  24 . Measurement of the cavity  24  without a guide pin  22  is also possible. The bands  210   a ,  210   b ,  210   c ,  210   d ,  210   e  are used to measure the depth of the cavity  24 . In some embodiments, the depth is measured at the peak  18   a . Like using a ruler, a user can visualize the last band that is visible over the peak  18   a  (e.g., the band  210   c  in  FIG. 6K , corresponding to a depth of about 8 mm). In some embodiments, the depth is measured at the peak  18   b , trough  20   a , trough  20   b , or some other portion of the end surface  16 . If the cavity  24  has an incorrect depth, if the second end  204  is not able to fit in the cavity  24 , or the second end  204  evidences other issues, the drill bit  300  or another drill bit can be used to correct the defect in the cavity  24 .  FIG. 6L  shows the placer  200  being proximally retracted over the guide pin  22  after measuring the cavity  24 . 
       FIG. 6M  shows the guide pin  22  being removed from the first metacarpal bone  12 . A sharp distal end of the guide pin  22 , which can pierce the bone during tamping and/or help to wedge the guide pin  22  through the bone, is visible. In some embodiments in which an implant comprises a bone anchor, the bone anchor may fit in a hole created by the guide pin. 
       FIGS. 6N-6T  show preparation of the implant  100  for deployment using a deployment system comprising the introducer  400  and the plunger  500 . The deployment preparation can be before, during, or after other steps of the procedure. For example, a first user can prepare the implant  100  for deployment while a second user forms the cavity  24 , which can reduce overall operation time. In some embodiments, the implant  100  is soaked in saline, water, or another fluid or otherwise treated prior to implantation. In  FIG. 60 , the bottom surface  104  of the implant  100  is aligned for placement in the proximal end  404  of the introducer  400 . The implant  100  is oriented so that the trough  120   a  (alternatively, the trough  120   b ) is rotationally aligned with the indicia  416 , as shown by the dashed line  25 , which shifts account for the introducer thickness in the perspective view. In the orientation of  FIG. 60 , the peaks  118   a ,  118   b  should face the top and bottom and the troughs  120   a ,  120   b  should face the sides. In  FIG. 6P , the implant is positioned partially in the introducer  400 . Further advancement into the introducer  400  may be limited by the flared shape  414 . 
       FIG. 6Q  shows the use of the distal end  502  of the plunger  500  approaching the upper surface  102  of the implant  100 . The topography or contours of the distal end  502  of the plunger  500  may correspond to the topography or contours of the end surface  102  of the implant.  FIG. 6R  shows engagement of the plunger  500  with the implant  100 . The indicia  416  of the introducer  400  show that the implant  100  is still properly aligned in the introducer  400 . In  FIG. 6S , the plunger  500  is advanced in the direction shown by the arrow  26  to advance the implant  100  into the introducer  400 . In some embodiments, the plunger  500  is held stationary and the introducer  400  is advanced in the direction opposite the arrow  26 . In some embodiments, the plunger  500  is advanced in the direction  26  and the introducer  400  is advanced in the direction opposite the arrow  26 . The plunger  500  can help advance the implant  100  past the flared shape  414 , radially inwardly compressing the implant  100 . In some embodiments, the implant  100  is compressed by between about 5% and about 50% (e.g., about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, ranges between these values, etc.) by the flared shape  414  of the introducer  400 . In  FIG. 6T , the plunger  500  is advanced to a deployment position. The indicia  516  and the indicia  416  can be used to verify that the implant  100 , now proximate to the distal end  402  of the introducer  400 , is still aligned, as shown by the dashed line  27 , which shifts account for the introducer thickness in the perspective view. If the implant  100  is not aligned, the implant  100  may be deployed from the distal end  402  of the introducer by further advancing the plunger  500 , and the loading process may be started over at  FIG. 6N  using the same implant  100  or a different implant. In some embodiments in which a same implant  100  is used, the implant may be treated prior to reloading (e.g., soaked for a period of time prior to reloading). 
       FIGS. 6U-6X  show deployment of the implant  100  in the cavity  24  in the first metacarpal bone  12 . In  FIG. 6U , the introducer  400  is advanced towards the cavity  24 . During the advancement, the indicia  416  are aligned with contours of the end surface  16 , as shown by the dashed line  29 , which shifts account for the introducer thickness in the perspective view. In some embodiments, the line of the indicia  416  is aligned to a trough  20   b  of the end surface  16 . Various alignment processes described herein may be described as concave-to-convex. 
     In  FIG. 6V , the neck portion  410  of the introducer  400  is positioned at least partially within the cavity  24  in which the implant  100  will be positioned. The shoulder  412  acts as a depth stop.  FIG. 6V  also shows the alignment of the indicia  416  with the trough  20   b  and the indicia  516 , as shown by the dashed line  31 , which shifts account for the introducer thickness in the perspective view. In some embodiments, the introducer  400  is sized, shaped, and otherwise configured to that the neck portion  410  fits generally snugly in the cavity  24 . The plunger  500  is illustrated with the head portion  512  in a first position. 
     In  FIG. 6W , the head portion  512  is distally advanced in the direction of the arrow  28  to urge the implant  100  out of the distal end  402  of the introducer  400  and in the cavity  24 . The plunger  500  can be operated manually and/or with the assistance of an external power-assist device (e.g., mechanically, pneumatically, hydraulically, etc.), as desired or required. The lower surface  104  of the implant  100  is located at or proximate to the bottom or floor of the cavity  24 . 
       FIG. 6X  shows the implant  100  after being deployed in the anatomical position and the deployment device being proximally retracted. The peak  118   a  of the implant  100  is aligned with the peak  18   a  of the end surface  16 , the peak  118   b  of the implant  100  is aligned with the trough  18   b  of the end surface  16 , the trough  120   a  of the implant  100  is aligned with the trough  20   a  of the end surface  16 , and the trough  120   b  of the implant  100  is aligned with the trough  20   b  of the end surface  16 . If the alignment is incorrect, the guide pin  22 , for example, can be used to urge the implant  100  out of the cavity  24 . The implant is between about 1 mm and about 3 mm proud above the end surface  16 , for example measured peak-to-peak (e.g.,  18   a  to  118   a  or  18   b  to  118   b ) or trough-to-trough (e.g.,  20   a  to  120   a  or  20   b  to  120   b ). 
     In  FIGS. 6Y and 6Z , the thumb is bent so that the first metacarpal bone  12  is in a normal anatomical position with respect to the trapezium  10 . The incision  14  may then be stitched or otherwise closed. 
     Although several embodiments and examples are disclosed herein, the present application extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the various inventions and modifications, and/or equivalents thereof. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. Accordingly, various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, the scope of the various inventions disclosed herein should not be limited by any particular embodiments described above. While the embodiments disclosed herein are susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are described in detail herein. However, the inventions of the present application are not limited to the particular forms or methods disclosed, but, to the contrary, cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element and/or the like in connection with an implementation or embodiment can be used in all other implementations or embodiments set forth herein. 
     In any methods disclosed herein, the acts or operations can be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence and not be performed in the order recited. Various operations can be described as multiple discrete operations in turn, in a manner that can be helpful in understanding certain embodiments; however, the order of description should not be construed to imply that these operations are order dependent. Additionally, any structures described herein can be embodied as integrated components or as separate components. For purposes of comparing various embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, embodiments can be carried out in a manner that achieves or optimizes one advantage or group of advantages without necessarily achieving other advantages or groups of advantages. 
     The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “deploying an implant” include “instructing deployment of an implant.” The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example ±5%, ±10%, ±15%, etc.). For example, “about 1 mm” includes “1 mm.” Phrases preceded by a term such as “substantially” include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example, “substantially rigid” includes “rigid,” and “substantially parallel” includes “parallel.”