Mid-Term Outcomes of Bone Marrow Stimulation for Primary Osteochondral Lesions of the Talus: A Systematic Review

CATEGORY: Ankle, Arthroscopy, Sports INTRODUCTION/PURPOSE: Arthroscopic bone marrow stimulation (BMS) is the most common reparative surgical intervention in the treatment of small osteochondral lesions of the talus (OLT). BMS has shown favorable short term clinical outcomes but several recent studies have shown less satisfactory results in the mid- to long-term due to fibrocartilagenous repair tissue deterioration over time following BMS. However, conflicting results with good mid- to long-term outcomes following BMS have been reported. There is still a lack of evidence on the success rates of BMS at mid-term and longer-term follow-up. The purpose of this systematic review was to evaluate the clinical evidence of mid- to long-term outcomes following BMS for the treatment of OLT. METHODS: A systematic search of the MEDLINE, EMBASE and Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological quality of evidence was decifered using the Modified Coleman methodology score (MCMS). Studies reporting outcomes of BMS for primary ostechndral lesions at a minimum 4-year follow-up were included. Clinical outcomes, radiological outcomes, and reported data were evaluated. RESULTS: Fifteen studies containing 853 patients (858 ankles) were included at a weighted-mean follow-up time of 71.9 (48-141) months. The mean age was 35.3 (24.7-41.9) and the mean lesion size was 110.5mm2 (87-140). Nine studies (60%) used the AOFAS ankle hindfoot score with a weighted-mean postoperative score of 89.9 (78.4-91.8). Six studies showed both pre and post-operative AOFAS scores and showed a weighted-mean improvement of 24.5 (16-38.5). Four studies utilised the VAS score. The weighted-mean postoperative VAS scores were 2.4 (1.8-2.6). Three studies (20%) measured post-opeartive MRI at mid-term using the MOCART score and showed 48% complete filling, 74% complete integration, 76% surface damage, and 78% inhomogeneous repair tissue. Complication rate was 3.2% and reoperation rate was 6% following BMS at mid-term. CONCLUSION: This systematic review found good clinical outcomes following BMS for primary OLT at mid-term follow-up based on the AOFAS score. The complication rates were relatively low and the data showed a reoperation rate of 6% at mid-term. However, the radiological and MRI outcomes did not show similarly positive results, which may lead to recurrence and reoperation at long-term. Data were variable and numerous aspects largely under-reported in the literature relevant to the systematic review. Further high quality studies, a validated outcome scoring system and further MRI reports are required to accurately assess the success of BMS at mid-term.