SLR - September 2018 - Ridhi Mehta

The Presence and Degree of Bone Marrow Edema Influence Midterm Clinical Outcomes After Microfracture for Osteochondral Lesions of the Talus

Reference: Shimozono Y, Hurley ET, Yasui Y, Deyer YW, Kennedy JG. The Presence and Degree of Bone Marrow Edema Influence Midterm Clinical Outcomes After Microfracture for Osteochondral Lesions of the Talus. The American Journal of Sports Medicine. 2018 Aug;46(10): 2503–2508.

Scientific Literature Review

Reviewed By: Ridhi Mehta, DPM
Residency Program: Mercy Hospital and Medical Center, Chicago, IL

Podiatric Relevance: Osteochondral lesions of the talus are a common condition seen and treated by foot and ankle surgeons. Treatment of osteochondral lesions of the talus has been a widely researched and debated topic in podiatric literature. Many treatment options exist and have been discussed in literature, including microfracture of the talus. However, limited research has been directed toward long-term outcomes of microfracture on osteochondral defects. This article follows 43 patients in an attempt to determine the correlation between the extent of bone marrow edema (BME) and clinical outcomes of patients after undergoing microfracture of the talus at short-term and midterm follow-up.

Methods: This article was a level III cohort study of patients who underwent microfracture between 2008 and 2013. Treatment for microfracture was determined by lesion size (<15 mm). Forty-three patients were included in the study after inclusion and exclusion criteria were met. BME was evaluated using magnetic resonance imaging. Clinical outcomes were measured using the Foot and Ankle Outcome Score (FAOS). Standard arthroscopic portals were used, after debridement and curettage, and microfracture was performed at a depth of 3 mm and holes spaced 3 to 4 mm apart. Patients were kept NWB for two weeks, and full WB was achieved at six weeks, upon which physical therapy was then initiated. Postoperative MRI was performed at two years and four years postoperatively. BME was assessed using a grading system from zero to three, zero being no BME, one being <25 percent of talar volume, two between 25 percent and 50 percent of talar volume and three being >50 percent talar volume.

Results: No statistically significant differences were found between clinical outcomes and BME grade at two-year follow-up. However, at four-year follow-up, there was a statistically significant difference between clinical outcomes and BME grade, with poorer outcomes being correlated with a higher BME grade. Seventy-four percent of patients still had BME at four-year follow-up.

Conclusions: There were no significant differences in clinical outcomes at short-term (two-year) follow-up between patients who had BME and who did not on MRI. In addition, there were no significant differences between clinical outcome and BME grade at short-term follow-up. At midterm (four-year) follow-up, the presence of BME had a correlation with poorer clinical outcomes. Thus, this study suggests that BME at midterm follow-up after microfracture for osteochondral defects may be pathological rather than postreactive as seen at short-term follow-up and is related to poorer clinical outcomes. 

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