The purpose of this trial is to evaluate the safety and effectiveness of the Biphasic Cartilage Repair Implant (BiCRI) compared to marrow stimulation in the treatment of chondral and osteochondral lesions located on the medial femoral condyle, lateral femoral condyle, or trochlea of the knee. The hypothesis is that the BiCRI provides an improvement in pain and function as compared to baseline, that is no worse than marrow stimulation at 1 year.

Inclusion Criteria

1. Male or female presenting with a single, symptomatic chondral or osteochondral lesion of the medial or lateral femoral condyles or the trochlea requiring primary surgical intervention

2. Skeletally mature (epiphyses are confirmed to be closed on x-ray)

3. ICRS grade 3-4 lesion, Outerbridge grade 4, or OCD grades 3-4

4. Lesion size requires no more than 2 implants (assuming patient were to be randomized to the treatment group). Lesion size will be assessed at the time of the study procedure for all subjects. If the size of the lesion is appropriate for 1 or 2 implants the patient will be randomized. If the lesion is found to be too large the patient will not be included in the trial, but will be treated according to standard of care. Lesion sizes that are considered appropriate include the following:

   • Lesion is 3mm x 3mm or larger and can be completely covered by the small (12.5mm diameter) sizer (excluding small fissures). This lesion should be treated with 1 implant. or
   • Lesion is 3mm x 3mm or larger and cannot be covered by the small sizer, but can be completely covered by the large (oval shaped) sizer (excluding small fissures). This lesion should be treated with 2 implants.

5. Willing and able to refrain from taking pain medications (including: narcotic and non-steroidal anti-inflammatory drugs) for 7 days prior to the baseline preoperative visit and for 7 days prior to the 12-month postoperative visit (i.e., a "wash out" period)

6. Willing and able to return for follow-up over a one year post-operative period

7. Willing and able to comply with all postoperative guidelines

Exclusion Criteria

1. ≥ 55 years old

2. Lesions > grade II on the articular surface of the tibia or patella

3. Kissing lesions (defined as an opposing lesion > grade II on the surface of the tibia or patella). Lesion ≤ grade II on opposing surface would be acceptable.

4. Prior surgical treatment of the lesion

5. Lesion would require more than 2 implants (assuming patient were to be randomized to the treatment group). Lesion sizes that are not considered appropriate include the following:

   • Lesion is smaller than 3mm x 3mm
   • Lesion cannot be completely covered by the large sizer

6. Lesion will require bone grafting

7. Rheumatoid arthritis and other inflammatory arthritis

8. Concomitant comorbidities, such as:

   • ACL instability that will not be corrected before or during the study procedure ("ACL instability" defined as the presence of a positive "pivot shift" test)

   • Significant knee instability that will not be corrected before or during the study procedure

   • Significant malalignment (varus or valgus deformity, patellar malalignment) that will not be corrected before or during the study procedure. Significant malalignment defined as:

     • Any joint space narrowing as compared to the same compartment in the contralateral knee.
     • Mechanical axis alignment outside the tibial spines.
     • Patellofemoral subluxation on sunrise view.
     • History of patellar dislocation or subluxation.

   • Severe meniscal damage ("Severe meniscal damage" defined as > 50% of the meniscus missing or a radial tear extending to the meniscal-synovial junction)

   • Knee stiffness, defined as:

     • Flexion contracture >10°
     • Flexion degree < 115°

9. Body Mass Index (BMI) > 35.0

10. Local or systemic infection, not including asymptomatic urinary tract infection if treated with antibiotics preoperatively

11. Pregnancy or breast feeding

12. Prisoner

13. Patient is involved in a personal litigation (e.g. Worker's Compensation lawsuit) that relates to their knee surgery

14. Patient is actively participating in another medical device, drug, or biologic investigation (active defined as within the last 30 days)

15. Patient otherwise meets the study criteria but refuses to consent in writing to participate in the study