Subchondroplasty® Knee RCT

Inclusion Criteria:

   - Candidates must meet ALL of the following:

      1. Voluntary signature of the Institutional Review Board/Research Ethics Board
      approved Informed Consent,

      2. Male or female subjects between the ages of 30 to 75 years,

      3. Body Mass Index ≤ 40 (BMI=kg/m2),

      4. Has experienced pain in study knee for at least 3 months,

      5. Kellgren-Lawrence grade 1-3 Osteoarthritis, as reviewed on preoperative XR
      imaging, in the study knee,

      6. BML is confirmed on T2 weighted or Proton Density MR Imaging by presence of white
      signal,

      7. Single BML of tibia, single BML of femur, or adjoining BML's of tibia & femur, in
      the same compartment, extending to the articular surface of the joint,

      8. Surgical candidate for knee arthroscopy due to mechanical symptoms, meniscus
      tear, loose body and/or synovitis,

      9. Must record a response, at the preoperative study visit, of moderate to extreme
      pain for any one of the KOOS Pain Scale questions, P2 through P9,

   10. Index knee alignment is defined radiographically as one of the following:
      Neutral, ≤ 6° mechanical varus, or ≤ 6° mechanical valgus,

   11. Ligaments in the study knee are stable,

   12. The contralateral (non-study) knee is stable and functional,

   13. Is refractory to conservative non-surgical management

         1. having failed 2 or more of the following: hyaluronic acid injection,
         corticosteroid injection, NSAIDs, physical therapy, bracing, activity
         modification, or minimal surgical intervention (e.g., arthroscopy,
         debridement/chondroplasty, and/or loose body removal)

         2. and is ≥ 3 months from the start of treatment,

   14. Must be physically and mentally willing and able, in the Investigator's opinion
      at the time of enrollment, to be compliant with the protocol - including all
      follow-up visits, survey completion, weight-bearing restrictions, and
      post-operative rehabilitation.

Exclusion Criteria:

   - Candidates will be excluded if they meet ANY of the following:

      1. BML caused by acute trauma less than 3 months prior to enrollment,

      2. Clinical and/or radiographic disease diagnosis of the index knee that includes
      any of the following:

         1. Kellgren-Lawrence Grade 4 Osteoarthritis with complete loss of joint space
         (bone-on-bone) or subchondral bone collapse,

         2. Rheumatoid arthritis, or history of septic or reactive arthritis,

         3. Gout or a history of gout or pseudogout in the affected knee,

         4. Has more than two clinically relevant BMLs in the index knee,

         5. Osteochondritis dissecans of the knee with significant bone loss,

         6. Collapse of subchondral bone,

         7. Clinically relevant BML located at ACL/PCL insertion,

         8. MRI evidence of frank ligament instability,

      3. Passive knee flexion < 110° or flexion contracture >30°,

      4. History of systemic diseases which could contribute to secondary arthropathies
      (e.g., sickle cell disease, hemochromatosis, or autoimmune disease),

      5. Has a neuromuscular, neurosensory, or musculoskeletal deficiency that limits the
      ability to perform objective functional assessment of either knee,

      6. If diabetic, blood glucose over 200 mg/dL at time of enrollment,

      7. Current daily tobacco or high nicotine product user or < 3 months from nicotine
      cessation,

      8. Presents a high surgical risk due to unstable cardiac and/or pulmonary disease,

      9. Has HIV or other immunodeficient state including subjects on immunosuppressant
      therapies, or has significant illness (metastasis of any type) that decreases the
      probability of survival to the 2 year endpoint,

   10. Is at substantial risk for the need of organ transplantation, such as renal
      insufficiency,

   11. Is pregnant or breast-feeding at the time of surgery,

   12. Has a history of any invasive malignancy (except non-melanoma skin cancer),
      unless treated with curative intent and with no clinical signs or symptoms of the
      malignancy for 5 years,

   13. Has primary bone tumor in the knee area,

   14. Anticipates having a lower extremity surgery other than the investigational
      surgery during the course of the study,

   15. Is participating concurrently in another clinical trial, or has participated in a
      clinical trial within 30 days of surgery,

   16. Is receiving prescription pain medication other than NSAIDs or acetaminophen for
      conditions unrelated to the index knee condition, chronic use of anticoagulants,
      or taking corticosteroids,

   17. Active joint infection or history of chronic joint infection at the surgical
      site,

   18. Prior total meniscectomy of index knee,

   19. Has primarily patellofemoral symptoms,

   20. Is indicated for concomitant procedures (i.e., microfracture, subchondral
      drilling, cartilage allograft, ligament or tendon repair, distal
      realignment/osteotomy, root repair) in the index knee, with the exception of
      incidental loose body removal, debridement, synovectomy, osteophyte removal in
      locations other than adjacent to BMLs, and/or partial meniscectomy,

   21. Has contraindications for Magnetic Resonance Imaging (MRI),

   22. Is receiving worker's compensation or is currently involved in litigation
      relating to the index knee,

   23. Has a history of substance abuse.