SLR - February 2020 - Michael Harrington
Reference: Choi SW, Lee GW, Lee KB. Arthroscopic Microfracture for Osteochondral Lesions of the Talus: Functional Outcomes at a Mean of 6.7 years in 165 Consecutive Ankles. American Journal of Sports Medicine. 2020 Jan; 48(1): 153-158.Scientific Literature Review
Reviewed By: Michael Harrington, DPM
Residency Program: Saint Francis Hospital & Medical Center – Hartford, CT
Podiatric Relevance: Arthroscopic microfracture treatment for osteochondral lesions of the talus has become the primary treatment option as the literature has shown good to excellent functional results in the short term follow up. The durability of the procedure, however, has been questioned due to recent studies that noted deteriorating functional results up to two years following the surgery. The goal of the present study was to evaluate the functional outcomes of arthroscopic microfracture for osteochondral lesions of the talus with a large sample size and an intermediate term follow up. It was hypothesized that arthroscopic microfracture could achieve good results and maintain satisfactory outcomes.
Methods: A case series of 165 ankles (156 patients) underwent standard arthroscopic microfracture repair for small to mid-sized osteochondral lesions of the talus. The mean size of the lesions was 73mm2. The mean follow up was 6.7 years with a range of 2-13.6 years. Several different functional outcome scores were used including the Foot & Ankle Outcome Score (FAOS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, Visual Analog Scale (VAS) as well as the 36-Item Short Form Health Survey (SF-36). The FAOS was used as the primary outcome measure while the AOFAS, VAS and SF-36 were used as secondary outcome measures. Pre-operative radiographs and MRIs were also evaluated and compared with the postoperative results at final follow up. The Berndt & Harty classification was used for radiograph assessment while the Anderson classification was used for MRI assessment. The functional scores and imaging were evaluated pre-operatively and compared to final follow up results by two orthopaedic surgeons who were not directly involved in the surgery
Results: The mean FAOS significantly improved including all of its subscores. The mean AOFAS ankle-hindfoot scale improved from 71.0 pre-operatively to 89.5 points at final follow up. The mean VAS score improved from 6.2 points pre-operatively to 1.7 points at final follow up. The mean SF-36 improved from 62.4 points pre-operatively to 76.2 points at final follow up. Of the 165 included ankles in the study, 13.3 percent underwent repeat arthroscopy due to recurrent symptoms. Factors including age, sex, BMI, lesion size and arthroscopic grade were not found to be related to the functional outcomes. Symptom duration, however, was found to negatively affect outcomes in the FAOS score.
Conclusions: This study revealed good functional outcomes and improvement in quality of life with an intermediate final follow up at a mean of 6.7 years postoperatively. These results support this technique for a reliable first line treatment for small osteochondral lesions of the talus. A limitation of the study is the minimum follow up of two years, which was not long enough to evaluate for late complications. Also, 82 percent of the patients had lesions smaller than 100mm2, which should be considered in the case of a larger osteochondral lesion. In conclusion, the present study demonstrates arthroscopic microfracture for small osteochondral lesions of the talus to be a reliable procedure to maintain satisfactory results over time.