A Study to Evaluate the Efficacy of BioCartilage® Micronized Cartilage Matrix in Microfracture Treatment of Osteochondral Defects

Inclusion Criteria:

1. The subject has signed the REB approved informed consent form (ICF) specific to thisstudy prior to enrollment.

2. The subject has an isolated OCD with minimum dimensions of 0.07 cm2 (0.3 cm indiameter) and maximum dimensions of 2.25 cm2 as confirmed by a pre-op MRI.

3. The subject is independent, ambulatory, and can comply with all post-operativeevaluations and visits.

4. The subject is at least nineteen (19) years of age and considered to be skeletallymature.

5. The subject has a combined bone and cartilage defect as determined by an MRI.

6. The patient has a stable ankle joint on history and has similar ligament stabilitywith the opposite ankle.

7. The subject has less than 15 degrees of hindfoot valgus and 5 degrees of hindfootvarus.

8. The subject has a chronic defect not secondary to acute trauma within the last 6months.

9. The patient (if having suffered a fracture) has no residual deformity of the tibia,fibula or syndesmosis.

10. The subject has a BMI of ≤ 40 kg/m².

11. The subject has exhausted non-operative treatment.

12. The subject has symptoms for less than a year.

13. Lesions on the subject must be contained.

Exclusion Criteria:

1. The subject has over 15 degrees of hindfoot valgus or 5 degrees of hindfoot varus.

2. The subject has an isolated OCD with dimensions greater than 2.0 cm2 on an MRIassessment.

3. The subject has an allergy to yeast-derived products.

4. The subject has implanted metallic devices (cardiac pacemakers, insulin pumps, andnerve stimulators), medically implanted clips, or other electronically, magneticallyor mechanically activated implants that would contraindicate an MRI scan of the foot.

5. The subject has claustrophobia that would inhibit their ability to undergo an MRI scanof the foot.

6. The subject has tested positive or has been treated for a malignancy in the past, issuspected of having a malignancy, or is currently undergoing radiation or chemotherapytreatment for a malignancy anywhere in the body, whether adjacent to or distant fromthe proposed BioCartilage® site.

7. The subject is physically or mentally compromised (e.g., currently being treated for apsychiatric disorder, senile dementia, Alzheimer's disease, etc.), to the extent thatthe investigator judges the subject to be unable or unlikely to remain compliant tofollow-up.

8. The subject is a prisoner, or is known or suspected to be transient.

9. The subject has documented evidence of a history (e.g. liver testing) of drug/alcoholabuse within the 12 months prior to screening for study entry.

10. The subject is pregnant or able to become pregnant but not practicing amedically-accepted form of birth control, and/or intending to become pregnant duringthis study period.

11. The subject currently has an acute infection in the area surrounding the surgicalsite.

12. The subject has a history of anaphylaxis or of multiple non-environmental allergiesthat may precipitate an anaphylactic reaction.

13. The subject's condition is bilateral and surgery is scheduled or to be scheduled overthe course of this trial for both feet.

14. The subject requires a concomitant osteotomy of the tibia, fibula, or calcaneus forhindfoot deformity.

15. The subject requires a concomitant hindfoot fusion or has had a hindfoot fusion forhindfoot arthritis or deformity.

16. The subject is undergoing any concomitant surgery that may invalidate the outcomescores such as forefoot surgery or fusions, tendon transfers or ligamentreconstructions. Heel cord lengthening is permitted.

17. The subject has an OCD of the tibia in isolation or in combination with the talarlesion

18. The subject is addicted to nicotine and on nicotine containing medication such as gumor a patch; or using nicotine containing substances such as cigarettes, cigars, pipesmoking or chewing tobacco.

19. The subject abuses cocaine or cocaine derivative drugs.

20. The subject has a known hypersensitivity to aprotinin.

21. The subject has diabetes with an HBA1c> 7.5.

22. The subject is unable to give informed consent.

23. The subject is unable to comply with follow-up.

24. The subject is unable to communicate with the research team.