Allograft Versus Autograft Osteochondral Transplant for Chondral Defects of the Talus: Systematic Review and Meta-analysis

SLR - July 2022 - Jake Semon, DPM

Reference: Migliorini F, Maffulli N, Baroncini A, Eschweiler J, Knobe M, Tingart M, Schenker H. Allograft Versus Autograft Osteochondral Transplant for Chondral Defects of the Talus: Systematic Review and Meta-analysis. Am J Sports Med. 2021 Sep 23:3635465211037349. doi: 10.1177/03635465211037349. Epub ahead of print. PMID: 34554880.

Level of Evidence: 4

Review By: Jake Semon, DPM
Residency Program: Metrowest Medical Center, Framingham, Massachusetts

Podiatric Relevance:
OCDs of the talus are common, and treatment of injuries to articular cartilage are challenging. Effectiveness of microfracture is limited to smaller lesions, and osteochondral transplant is indicated in larger effects ranging from 1-4 cm2. This study aims to evaluate the difference in outcomes between allografts vs autografts by measuring patient satisfaction, MRI findings, and complication rates.

Methods: 
  • Meta analysis which included 40 studies, totaling 1174 procedures
  • Mean follow up of 46.5 +/- 25 months in the pooled studies
  • Outcomes were measured using the Visual Analog Scale, the AOFAS score, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score, as well as comparing rates of failure and revisional surgeries. 
  • Any studies examining end stage ankle arthritis were excluded.
Results:
  • The literature search yielded 35 retrospective and 4 prospective studies, along with one randomized controlled clinical trial.
  • The autograft group had higher MOCART scores (mean difference 10.5, P = 0.04) and higher AOFAS scores (mean difference 4.8, P = 0.04) relative to the allograft group, while both treatment groups had similar VAS scores (mean difference 0.2, P = 0.4)
  • In looking at the two comparative studies within the meta-analysis, there were significantly lower rates of revisions and failure for the autograft group (Odds ratio 12.0, P = .02; odds ratio 13.8, P = .004 for revision and failure rates respectively.
  • While patient satisfaction scores are similar at midterm follow up, the revision and failure rates (14.7 percent allograft group) suggest that autograft should be the preferred option.

Conclusion:
The authors of this study conclude that their study was suggestive of higher rates of failure and revision rates when using allografts in the treatment of osteochondral defects of the talus vs autografts. Allografts are associated with higher costs limited availability, and greater risk of disease transmission, while autografts contend with the potential for donor site morbidity. The authors reference the anterosuperior condyle region, and the lateral aspect of the intercondylar notch as safe sites to harvest autologous chondral plugs. Past literature suggests that increased immune response may play a role in increased complication rates when using allograft. Overall, there is a need for higher quality comparative studies in order to draw stronger conclusions.