AANA Lab Course 908-Foot and Ankle Arthroscopy (APEx)-Autologous and Allograft Osteochondral Transfer_ When Microfracture Isn't Enough-John Kennedy, M.D.

Autologous and Allograft Osteochondral Transfer_ When Microfracture Isn't Enough-John Kennedy, M.D.

Pdf Summary

This presentation by Dr. John G. Kennedy from NYU Langone Health focuses on autologous and allograft osteochondral transfer (AOT) for osteochondral lesions (OCL) of the ankle, especially when microfracture is insufficient. 

Key points include:

1. <strong>Autologous Osteochondral Transplant (AOT):</strong>  
- Recommended for lesions larger than 10 mm or 100 mm², as microfracture has high failure rates with lesions >15 mm or >150 mm².  
- Clinical outcomes in athletes are generally excellent, with studies showing ~75-90% satisfaction and return to sport within 6 months.  
- Predictors such as BMI, lesion location, number of grafts, or previous microfracture do not reliably influence outcomes.  
- Donor site morbidity from the knee is low (~5%) and decreases over time despite some reports of knee pain.  
- Postoperative cyst formation is common (~65%) but typically asymptomatic and may resolve by 1-2 years. Use of concentrated bone marrow aspirate (CBMA) reduces cyst incidence.  
- Mechanical considerations emphasize precise graft placement (flush within ~1 mm) to avoid elevated contact pressure and graft malunion risks, though good functional outcomes are reported.  
- MRI T2 mapping shows good cartilage restoration at mid-term follow-up.

2. <strong>Osteochondral Allograft:</strong>  
- Fresh allografts from donors aged 16-40 implanted within 10-28 days have more variable outcomes.  
- Comparative studies show autografts generally outperform allografts in functional scores (FAOS, SF-12), with lower cyst and failure rates.  
- Allografts have higher failure rates (~18.8%) and more cyst formation within the graft than autografts.

3. <strong>Summary:</strong>  
- Autologous AOT is preferred for larger lesions in athletes and general populations due to better outcomes and lower complications.  
- Allograft use is associated with poorer outcomes and higher failure.  
- CBMA adjunct improves radiological and clinical outcomes after AOT.  
- Knee donor site morbidity is minimal and acceptable.

Overall, AOT offers a reliable surgical solution for osteochondral lesions when microfracture fails, with autografts favored over allografts for better durability and function.

Keywords

Autologous Osteochondral Transfer

Allograft Osteochondral Transfer

Osteochondral Lesions

Ankle Surgery

Microfracture Failure

Athlete Outcomes

Donor Site Morbidity

Bone Marrow Aspirate Concentrate

Graft Placement Precision

MRI T2 Mapping