Immediate Postoperative Weightbearing Following Arthroscopic Bone Marrow Stimulation for Talar Osteochondral Lesions: A Matched Cohort Study.

Abstract

Background: Bone marrow stimulation (BMS) is the most frequently performed surgical procedure for osteochondral lesions of the talus (OLTs). After the surgical intervention, one of the first goals of rehabilitation is to resume weightbearing. This study aims to compare clinical and radiologic outcomes between immediate weightbearing and delayed weightbearing, which represent unrestricted weightbearing and weightbearing starting at 6 weeks postoperatively.

Methods: All patients who underwent BMS for their OLT between July 2019 and September 2022 in our clinic were screened for eligibility. Patients were retrospectively included with prospective collected data and were matched into 2 groups, the immediate weightbearing group or the delayed weightbearing group. The following variables were used for matching: age, gender, side, lesion size (volume and surface measured on CT scans), primary or nonprimary lesion, body mass index (BMI) and the numeric rating scale (NRS) of pain during walking. The primary outcome of this study is the comparison of the change in NRS of pain during walking between baseline and 12 months postoperatively, between both groups. Secondary outcomes consist of change in the NRS of pain during running, NRS pain during stairclimbing, NRS pain during rest, 36-Item Short Form Health Survey, Foot and Ankle Outcome Score, return to work, return to sport, and radiologic outcomes between both groups at 12 months.

Results: After matching, 13 patients per group were included. Both groups showed improvement in NRS pain during walking from baseline to 12 months postoperatively. The difference in change scores between immediate and delayed weightbearing was not statistically significant (P = .57, 95% CI -3.25 to 1.86). A higher proportion of patients in the immediate weightbearing group exceeded the minimal clinically important difference threshold of 2 points compared with the delayed group (OR = 1.9, 95% CI 0.30-11.7), although this was not statistically significant. No significant between-group differences were observed in secondary clinical or radiologic outcomes, nor in return-to-work or return-to-sport rates.

Conclusion: This matched cohort study found no statistically significant difference in clinical or radiologic outcomes at 12 months between immediate and delayed weightbearing following arthroscopic BMS for talar osteochondral lesions. Although early weightbearing may be feasible and well tolerated, the small sample size and wide CIs limit the strength of conclusions. These findings should be considered hypothesis-generating and underscore the need for larger, prospective trials.