MAKO-Uni-Knee Arthroplasty Clinical Outcomes and Function
Condition: Clinical Outcomes
Study type: Interventional

Summary: 
      This study represents a single-surgeon/institution, non-randomized, consecutive series,
      prospective and comparative cohort design. The Principal Investigator is anticipating 100
      study patients in the INTACT group and 35 patients in the Anterior Cruciate
      Ligament-Deficient group.The schedule of events lists the imaging procedures and
      questionnaires to be completed at each visit.

      Subjects will be consented and enrolled within 28 days prior to surgery and participate in
      follow-up visits for two years following their Unicompartmental Knee Arthroplasty. A 3-year
      enrollment duration is anticipated to enroll a minimum and consecutive series of 25 patients
      in the experimental Anterior Cruciate Ligament-deficient group. Over the same enrollment
      duration, 100+ patients with intact Anterior Cruciate Ligaments are expected to be in the
      control group and undergo Unicompartmental Knee Arthroplasty. The enrollment duration (3
      years) and total study duration (5 years) are based on patient volume estimates provided by
      the Principal Investigator.
    

Detailed description: 
      To compare functional and clinical outcomes in patients with and without intact Anterior
      Cruciate Ligament undergoing uni-compartmental knee arthroplasty with MAKOplasty Robotic-Arm
      Assisted Surgery. The primary outcome measurement tools utilized will be the Knee Society
      Score (KSS) and Knee Injury and Osteoarthritis Outcomes Score (KOOS,JR). Both the Knee
      Society Score and Knee Injury and Osteoarthritis Outcomes Score (KOOS,JR) are validated
      scoring systems. Patient-reported outcome data will be collected at the following study time
      points:

        -  Preoperatively - Knee Society Score: Pre-Op, Knee Injury and Osteoarthritis Outcomes
           Score

        -  3 weeks (±1 week) - Knee Society Score: Post-Operative, Knee Injury and Osteoarthritis
           Outcomes Score , Subject Global Satisfaction Survey

        -  6 weeks (± 1 week) - Knee Society Score: Post-Operative, Knee Injury and Osteoarthritis
           Outcomes Score, Subject Global Satisfaction Survey

        -  3 months (± 2 weeks) - Knee Society Score: Post-Operative, Knee Injury and
           Osteoarthritis Outcomes Score, Subject Global Satisfaction Survey

        -  1 year (± 1 month) - Knee Society Score: Post-Operative, Knee Injury and Osteoarthritis
           Outcomes Score, Subject Global Satisfaction Survey

        -  2 years (± 2 months) - Knee Society Score: Post-Operative, Knee Injury and
           Osteoarthritis Outcomes Score, Subject Global Satisfaction Survey

      Subject Identification

      Each subject will be assigned a unique subject number. Subject numbers will not be
      re-assigned or re-used for any reason. Only assigned subject numbers and associated subject
      age, Anterior Cruciate Ligament integrity classification, pre/intra-operative imagery
      information, and temporal outcome data will be shared with Sponsor. Only subjects who meet
      the inclusion/exclusion criteria and sign the Inform Consent Form will be assigned a unique
      study identification number.

      Pre-Operative Anterior Cruciate Ligament Integrity

      The structural integrity of the Anterior Cruciate Ligament will be determined clinically and
      pre-operatively with the following:

        1. Lachman's anterior drawer test: Performed while the patient is in the supine position
           with the knee in 20° of flexion. The distal femur is fixed with one hand, while the
           other hand holds the proximal tibia with the thumb on the anteromedial joint line. The
           tibia is pulled ventrally, and the examiner estimates the ventral displacement of the
           tibia with respect to the femur. There are three possible outcomes: graded as 1+ (0-5 mm
           of displacement), 2+ (6-10 mm of displacement) or 3+ (greater than 10 mm of
           displacement) A 2+ or 3+ Lachman's test grade will be indicative of ACL instability.

        2. Anterior drawer test: Performed with the patient in the supine position with the hips
           flexed to 45°, the knees flexed to 90° and the feet flat on the table. The thumbs are
           placed along the joint line on either side of the patellar tendon and the tibia is drawn
           forward anteriorly. An increased amount of anterior tibial translation compared with the
           opposite limb or lack of a firm end point may be indicative of either a sprain of the
           anteromedial bundle or complete tear of the Anterior Cruciate Ligament. If the tibia
           pulls forward or backward more than normal, the test is considered positive.

        3. Pivot-Shift Test: Test is performed with the patient lying in supine position with the
           hip passively flexed to 30°.The examiner stands lateral to the patient on the side of
           the knee that is being examined. The lower leg and ankle is grasped maintaining 20
           degrees of internal tibial rotation. The knee is allowed to sag into complete extension.
           The opposite hand grasps the lateral portion of the leg at the level of the superior
           tibiofibular joint, increasing the force of internal rotation. While maintaining
           internal rotation, a valgus force is applied to the knee while it is slowly flexed. If
           the tibia's position on the femur reduces as the knee is flexed in the range of 30 to 40
           degrees or if there is an anterior subluxation felt during extension the test is
           positive for instability.

        4. Biodex knee laxity test: This quantitative evaluation of knee laxity will be performed
           in accordance with the standardized procedures utilized by the Department of Physical
           Therapy at Florida Orthopaedic Institute.

      Plain X-Ray

      Knee osteoarthritis will be diagnosed and subjectively graded by taking plain radiographs in
      accordance with the Principal Investigator's Standard of Care, which include a (1)
      weight-bearing (WB) postero-anterior (PA) view, (2) sunrise view, and (3) lateral view.
      Degenerative disease of the knees will be graded per the Ahlback - Grades 1-5, increasing in
      severity or Kellgren and Lawrence Grade 0-4, increasing in severity classification systems.
      The Principal Investigator also uses a subjective classification system of mild, moderate, or
      severe osteoarthritis, which is captured in the clinic note.

      Magnetic Resonance Imaging

      A standardized imaging protocol will be utilized for all Magnetic Resonance Imaging images.
      Specifically, a 3D-proton density non-fat suppressed fast spin echo sequence shall be used.
      Magnetic Resonance Imaging of the knee will be obtained prior to surgery using the parameters
      as requested by the Sponsor using Florida Orthopaedic Institute Siemens Aera 1.5T Magnetic
      Resonance Imaging scanner: TR/TE=1000/46, Flip angle=120°, repetition time=1000msec, echo
      time=46msec, bandwidth=97.3 Hz/pixel, matrix size= 320x300 pixels. The Sponsor has requested
      the use of a 3T magnet, but Florida Orthopaedic Institute currently has 1.5T magnets in their
      Magnetic Resonance Imaging scanners, so this request cannot be accommodated. We will perform
      a scan with the 1.5T magnet and share with Sponsor to confirm that the available imagery
      information is acceptable for their purposes.

      Computed Tomography (CT) Scans

      A Computed Tomography scan of the knee will be obtained prior to surgery using the
      standardized partial knee arthroplasty Computed Tomography scanning protocol with bone
      mineral density (BMD) phantom protocol as provided by the Sponsor. Sponsor will provide the
      phantom for use during scanning. A pre-operative Computed Tomography scan is required as the
      Standard of Care for robotic-arm assisted knee procedures. Each patient's Computed Tomography
      scan is used to create a 3D model of the patient's anatomy for accurate implant planning,
      bone resection and implant placement.

      KOOS-JR

      The abbreviated version of the Knee Injury and Osteoarthritis Outcome Score (KOOS) survey is
      a validated and self-reported questionnaire (7 questions) designed to measure "knee health"
      as it reflects aspects of pain, symptom severity, and activities of daily living (ADL)
      including movement or activities that are directly relevant and difficult for patients with
      knee Osteoarthritis.The Knee Injury- Osteoarthritis Outcomes Score-JR knee survey consists of
      7 questions pertaining to knee stiffness, knee pain, and physical function. The survey will
      be administered to all patients at baseline, 3 weeks, 6 weeks, 3 months, 1 year and 2 years.

      KSS

      The knee society score has been in use for over 20 years and is a simple, objective means to
      measure a patient's functional ability before and after surgery (11-13). It includes ROM
      assessment. The Principal Investigator will utilize the updated Knee Society Score (2011),
      which has been modified to include both an objective physician-derived component with a
      subjective patient-derived component that evaluates pain relief, functional abilities,
      satisfaction, and fulfillment of expectations. This updated scoring system prioritizes the
      patient perspective, to better track patient expectations, satisfaction, and activity levels
      than was possible with its predecessor. Patients will complete this survey with the Principal
      Investigator at all study time points.

      Global Satisfaction Survey

      This custom, 2-page survey has been designed by the study team to track patient satisfaction
      after their Unicompartmental Knee Arthroplasty over time. It's a simple, seven-item survey
      that also includes a Visual Analogue Scale for knee pain. The survey will be administered to
      all patients at all post-operative visits.

      Intra-Operative Anterior Cruciate Ligament Integrity

      During surgery, the Anterior Cruciate Ligament will be inspected, manually stressed and
      probed following standard techniques to assess its structure and function.The state of the
      Anterior Cruciate Ligament will be recorded and classified into one of four categories per
      these intra-operative examinations and available pre-operative Magnetic Resonance Imaging
      data:

      Group 1 - intact Anterior Cruciate Ligament Group 2 - intact but fibrillated (frayed)
      ligament) Group 3 - nearly completely torn ligament (>50% and disrupted)

      Assessment will be performed by the Principal Investigator. Knees with Anterior Cruciate
      Ligaments classified as Group 1 and Group 2 will be accepted as functionally intact. Those
      classified as Group 3 will be deemed as having functionally absent Anterior Cruciate
      Ligaments.
    

Intervention name(s): Unicompartmental knee arthroplasty with the Mako Robotic Arm-assisted system.
Intervention type(s): Procedure
Intervention description(s): All patients will receive the RESTORIS MCK (Multicompartmental Knee) Implant System, which is approved for use in unicompartmental knee arthroplasty with the Mako Robotic Arm-assisted system. The femoral component is constructed from cobalt chrome (CoCr) and the tibial component is constructed from an ultra-high molecular weight polyethylene (UHMWPE) insert and titanium (Ti) baseplate. UKA will be facilitated with MAKO Robotic-Arm Assisted Surgery, which has been shown in prior studies to lower pain and result in more accurate implant placement than manual UKA in a randomized controlled trial.(15)
Other intervention name(s): UKA with Mako Robotic Arm-assisted system
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: During surgery, the ACL will be inspected, manually stressed and probed following standard techniques to assess its structure and function.(20, 21) The state of the ACL will be recorded and classified into one of four categories per these intra-operative examinations (22) and available pre-operative MRI data:
Group 1 - intact ACL ligament
Group 2 - intact but fibrillated (frayed) ligament)
Group 3 - nearly completely torn ligament (>50% and disrupted)
Assessment will be performed by the PI. Knees with ACLs classified as Group 1 and Group 2 will be accepted as functionally intact. Those classified as Group 3 will be deemed as having functionally absent ACLs
Masking: None (Open Label)
Primary purpose: Treatment