Spinal implant system and method

A spinal implant is provided that comprises a first vertebral engaging surface and a second vertebral engaging surface. A wall extends between the surfaces. A lattice is disposed adjacent the wall and extending between the surfaces. Systems and methods of use are disclosed.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for the treatment of musculoskeletal disorders, and more particularly to a surgical system and method for treating a spine.

BACKGROUND

Spinal pathologies and disorders such as scoliosis and other curvature abnormalities, kyphosis, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these spinal disorders includes fusion, fixation, correction, discectomy, laminectomy and implantable prosthetics. As part of these surgical treatments, spinal constructs, such as, for example, bone fasteners, spinal rods and interbody devices can be used to provide stability to a treated region. For example, during surgical treatment, interbody implants can be delivered to a surgical site for fixation with bone to immobilize a joint. This disclosure describes an improvement over these prior art technologies.

SUMMARY

In one embodiment, a spinal implant is provided that comprises a first vertebral engaging surface and a second vertebral engaging surface. A wall extends between the surfaces. A lattice is disposed adjacent the wall and extending between the surfaces. In some embodiments, systems and methods are provided.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a surgical system including a spinal implant and a method for treating a spine. In one embodiment, the systems and methods of the present disclosure are employed with a spinal joint fusion, for example, with a cervical, thoracic, lumbar and/or sacral region of a spine. In one embodiment, the spinal implant includes an interbody device, a plate and/or bone fasteners.

In some embodiments, the present system comprises a spinal implant including a lattice and a frame porous titanium interbody implant with an optimized modulus. In some embodiments, the present system comprises a spinal implant including a titanium implant. In some embodiments, the present system comprises a spinal implant including a lattice and a frame titanium interbody device with an optimized modulus that may be more efficiently manufactured using additive manufacturing techniques.

In some embodiments, the spinal implant includes an interbody spacer having a modulus in a range of the modulus of bone to reduce a risk of stress shielding in the interbody spacer. In some embodiments, the spinal implant includes an interbody spacer that combines a low modulus with ossification-enabling characteristics and bony ingrowth features that mechanically lock the implant to bone. In some embodiments, the spinal implant combines a modulus similar to bone, bony ongrowth, bony ingrowth and mechanical robustness. In some embodiments, the spinal implant includes an interbody spacer having a porous lattice contained within a frame.

In some embodiments, the frame includes external features such as teeth and corners. In some embodiments, the frame includes continuous faces for marking. In some embodiments, the frame includes a shell for a lattice of a frame so that no thin projections from the lattice are exposed. In some embodiments, the lattice includes a reduced modulus. In some embodiments, the lattice provides for bony ingrowth. In some embodiments, the lattice provides predictable pore placement under teeth of the interbody implant to minimize the distance that bone can grow before it interlocks with the implant. In some embodiments, the lattice provides predictable structural support placement within the implant.

In some embodiments, the spinal implant includes a porous titanium interbody spacer with bony ingrowth features and a modulus approximating bone. In some embodiments, the spinal implant includes teeth having solid tips. In some embodiments, the spinal implant includes pores positioned below teeth tips. In some embodiments, the spinal implant includes at least one solid face for marking. In some embodiments, the spinal implant includes solid corners for robustness. In some embodiments, the spinal implant includes at least one sight window. In some embodiments, the spinal implant includes a framework having an outer frame and an internal lattice.

In some embodiments, the spinal implant includes an interbody spacer having a modulus of elasticity in a range of approximately 300 megapascal (MPa) to approximately 12000 MPa. In some embodiments, the spinal implant includes an interbody spacer having a modulus of elasticity in a range of approximately 2 gigapascal (GPa) to approximately 3 GPa. In some embodiments, the spinal implant includes an interbody spacer having a lattice with openings completely through its frame. In some embodiments, the spinal implant includes an interbody spacer having a lattice with openings, such as, for example, lattice holes having a 0.75 millimeter (mm) diameter.

The following discussion includes a description of a surgical system and related methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are also disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning toFIGS. 1 and 2, there are illustrated components of a surgical system, such as, for example, a spinal implant system10.

Various components of spinal implant system10may have material composites, including the above materials, to achieve various desired characteristics such as strength, rigidity, elasticity, compliance, biomechanical performance, durability and radiolucency or imaging preference. The components of spinal implant system10, individually or collectively, may also be fabricated from a heterogeneous material such as a combination of two or more of the above-described materials. The components of spinal implant system10may be monolithically formed, integrally connected or include fastening elements and/or instruments, as described herein. In one embodiment, a spinal implant, as described herein, may be formed substantially of a biocompatible metal, such as titanium and selectively coated with a bone-growth promoting material, such as HA. In one embodiment, a spinal implant, as described herein, may be formed substantially of a biocompatible polymer, such as PEEK, and selectively coated with a biocompatible metal, such as titanium, or a bone-growth promoting material, such as HA. In some embodiments, titanium may be plasma sprayed onto surfaces of the spinal implant to modify a radiographic signature of the spinal implant and/or improve bony ongrowth to the spinal implant by application of a porous or semi-porous coating of titanium.

Spinal implant system10may be employed, for example, with minimally invasive procedures, including percutaneous techniques and/or mini-open surgical techniques to deliver and introduce instrumentation and/or implants, such as, for example, an interbody implant, at a surgical site within a subject body of a patient, which includes, for example, a spine. In some embodiments, the implant can include spinal constructs including one or more bone fasteners, spinal rods, connectors and/or plates. In some embodiments, various components of spinal implant system10may be utilized in open or traditional spinal surgical techniques.

Frame14includes an inner wall22that extends between surfaces18,20. Frame14includes an outer wall24that extends between surfaces18,20. Walls22,24are spaced apart between surfaces18,20and define one or more cavities26disposed between walls22,24. In some embodiments, wall22includes a portion22aand wall24includes a portion24a, which comprise a side frame14aof frame14. Portions22a,24aare spaced apart to define a portion of cavity26and connect end portions of frame14via side frame or bridge14a. In some embodiments, wall22includes a portion22band wall24includes a portion24b, which comprise a side frame14bof frame14. Portions22b,24bare spaced apart to define a portion of cavity26and connect end portions of frame14via side frame or bridge14b.

Cavity26includes an end portion26aand an end portion26b, as shown inFIG. 2, configured for disposal of one or more portions of lattice28. In some embodiments, lattice28may include one or more portions, layers and/or substrates. In some embodiments, one or more portions, layers and/or substrates of lattice28may be disposed side by side, offset, staggered, stepped, tapered, end to end, spaced apart, in series and/or in parallel. In some embodiments, lattice28defines a thickness, which may be uniform, undulating, tapered, increasing, decreasing, variable, offset, stepped, arcuate, angled and/or staggered.

In some embodiments, one or more layers of lattice28are disposed in a side by side, parallel orientation within cavities26a,26band extend between surfaces18,20. Lattice28includes one or more layers of a matrix of material, such as, for example, a latticework80. Latticework80includes a plurality of nodes82and openings84disposed in rows and columns and/or in series and parallel. Latticework80is disposed between walls22,24and surfaces18,20to reduce density of the implant body of interbody implant12. This configuration provides a low modulus of elasticity to the implant body of interbody implant12and increases flexibility.

In some embodiments, lattice28provides a low modulus of elasticity to the implant body of interbody implant12in a range of the modulus of bone. In some embodiments, frame14has a modulus of elasticity in a range of approximately 300 MPa to approximately 12000 MPa. In some embodiments, frame14has a modulus of elasticity in a range of approximately 2 GPa to approximately 3 GPa. In some embodiments, nodes82and openings84may be disposed in a diagonal orientation. In some embodiments, openings84extend completely through frame14. In some embodiments, openings84have a 0.75 mm diameter.

Wall24includes continuous and uninterrupted faces, such as, for example, solid corners72a,72b,72c,72d. The configuration of corners72a,72b,72c,72dwith wall24provides strength and robustness to the implant body of interbody implant12.

The implant body of interbody implant12includes a tissue penetrating member, such as, for example, a tooth30disposed transversely along surface18and/or surface20, as shown inFIG. 1. In one embodiment, implant12includes a plurality of teeth30. In one embodiment, teeth30may have various configurations, for example, parallel, converging, diverging, irregular, tapered, offset, staggered, uniform and non-uniform.

Each tooth30includes a portion32and a portion34that connect to form a cutting surface36. Surface36is configured to engage endplate tissue, such as, for example, soft tissues, bone and/or fluids to cut, shave, shear, incise and/or remove such tissue. Surface36includes a cutting tip, such as, for example, a solid cutting tip38. Each tooth30includes a surface42that defines at least one opening44. In some embodiments, one or more openings44are configured to form a porous tooth surface adjacent tip38. In some embodiments, at least one opening44guides, drives and/or directs the tissue cut by surface36, and/or other tissue and bone growth promoting material adjacent the surfaces of the implant body of interbody implant12.

In some embodiments, teeth30may be disposed in a serial and/or overlapping configuration to provide a matrix of teeth30. In some embodiments, teeth30are disposed along surface18and/or surface20such that cut osteogenic tissue and/or other bone growth promoting material create a mechanical interlock of the implant body of interbody implant12with a vertebral endplate and/or form a scaffold for bone growth.

Wall22includes a surface50that defines an opening, such as, for example, an axial opening52configured to receive an agent, which may include bone graft (not shown) and/or other materials, as described herein, for employment in a fixation or fusion treatment.

Wall24includes openings66disposed in columns and rows thereabout. Openings66are configured for disposal of tissue and/or other bone growth promoting material, which may include cut osteogenic tissue, to create a mechanical interlock of the implant body of interbody implant12with a vertebral endplate and/or form a scaffold for bone growth to facilitate fixation and fusion. Walls22,24define openings, such as, for example, windows70configured to facilitate positioning and disposal of an agent, which may include bone graft and/or other materials, as described herein. Walls22,24define an opening74configured to facilitate engagement with a surgical tool or instrument for positioning and alignment of the implant body of interbody implant12with tissue, as described herein.

Wall24includes a continuous and uninterrupted face, such as, for example, a solid face64. In some embodiments, face64is configured for disposal of visual indicia. In one embodiment, the visual indicia is configured to provide configuration and/or a dimension of interbody implant12. In some embodiments, system10may comprise a kit including a plurality of implants with visual indicia indicative of their respective configuration and dimension. In some embodiments, the visual indicia may include color coding to provide configuration and/or a dimension of interbody implant12.

In assembly, operation and use, as shown inFIG. 3, spinal implant system10, similar to the systems and methods described herein, is disposed with tissue, such as, for example, vertebrae V for treatment of a spinal disorder, such as those described herein, affecting a section of a spine of a patient. Spinal implant system10may also be employed with other surgical procedures.

To treat the affected section of vertebrae V, an incision is made with a surgical instrument, such as, for example, a scalpel. In some embodiments, a discectomy is performed adjacent the intervertebral space. In some embodiments, sequential trial implants are delivered and used to distract the intervertebral space and apply appropriate tension in the intervertebral space allowing for indirect decompression. In some embodiments, the size of interbody implant12is selected after trialing. In some embodiments, interbody implant12is visualized by fluoroscopy and oriented before malleting into the intervertebral space.

An inserter (not shown) is connected with interbody implant12via opening74to direct interbody implant12between vertebrae V1, V2such that surface18is disposed in a cephalad orientation of the body and surface20is disposed in a caudal orientation of the body. The inserter delivers interbody implant12through the incision to a surgical site for implantation into the intervertebral space S between vertebrae V1, V2.

As interbody implant12is inserted into space S, teeth30translate along the surface of endplate E1and/or endplate E2. Translation of teeth30along the surfaces of endplate E1and/or endplate E2cause teeth30and/or surfaces18,20to engage the soft tissues, bone and/or fluids of endplate E1and/or endplate E2for forming a mechanical lock of interbody implant12with vertebrae V1, V2. In an implanted position, as shown inFIG. 3, surface18engages endplate tissue of endplate E1and surface20engages endplate tissue E2.

Upon completion of a procedure, as described herein, the surgical instruments, assemblies and non-implanted components of spinal implant system10are removed and the incision(s) are closed. One or more of the components of spinal implant system10can be made of radiolucent materials such as polymers. Radiopaque markers may be included for identification under x-ray, fluoroscopy, CT or other imaging techniques. In some embodiments, the use of surgical navigation, microsurgical and image guided technologies may be employed to access, view and repair spinal deterioration or damage, with the aid of spinal implant system10. In some embodiments, spinal implant system10may include one or a plurality of plates, connectors and/or bone fasteners for use with a single vertebral level or a plurality of vertebral levels.

In one embodiment, spinal implant system10includes an agent, which may be disposed, packed, coated or layered within, on or about the components and/or surfaces of spinal implant system10. In some embodiments, the agent may include bone growth promoting material, such as, for example, bone graft to enhance fixation of the components and/or surfaces of spinal implant system10with vertebrae. In some embodiments, the agent may include one or a plurality of therapeutic agents and/or pharmacological agents for release, including sustained release, to treat, for example, pain, inflammation and degeneration.