Higher preoperative range of motion is predictive of good mid-term results in the surgical management of osteochondral lesions of the talus: a prospective multicentric study.

Introduction: Osteochondral lesions of the talus (OLT) are a frequent cause of pain in young patients and a new CT arthrographic classification system of OLT was recently proposed to help guide the choices of and standardize the indications for surgical treatment. The primary hypothesis was that this algorithm would result in a postoperative AOFAS score of ≥ 80/100. The secondary hypothesis was to identify the preoperative factors of successful surgery.

Methods: This was a prospective observational multicenter study. Eighty-six patients who underwent surgery for OLT after at least 6 months of unsuccessful conservative management were included for a mean follow-up of 15 months (12-36). Forty-nine patients with stage 1 OLT underwent microperforation, 2 patients with stage 2 OLT underwent a lift, drill, fill, and fix graft procedure with screw fixation, and 35 patients with stage 3 OLT were treated with mosaicplasty.

Results: After a follow-up of at least 1 year, 56 patients (65%) had an AOFAS score > 80 and the mean AOFAS score was 82 (16-100). A lower BMI (p = 0.038), a higher preoperative range of motion in the ankle (p = 0.033), higher preoperative AOFAS and FAOS scores (p = 0.001 and p = 0.011), and the presence of a preoperative bone bruise on MRI (p = 0.020) were good prognostic factors on univariate analysis. The presence of grade 1 osteoarthritis on the Van Dijk classification was predictive of a poor prognosis (p = 0.044). Multivariate analysis showed that a good preoperative range of motion (OR = 1.080 [1.020-1.150] p = 0.01) was predictive of a positive outcome, while grade 1 osteoarthritis was predictive of a poor outcome (OR = 0.147 [0.036-0.603] p = 0.008). The postoperative AOFAS decreased in six patients and 17 patients had at least one complication: six dysthesias of the superficial fibular nerve, two of the sural nerve, and nine stage 1 complex regional pain syndromes.

Conclusion: The new algorithm for OLT resulted in a postoperative AOFAS score of ≥ 80/100 in 65% of cases. The positive predictive factors of a successful postoperative outcome were the presence of a good preoperative range of motion and the absence of preoperative osteoarthritis.

Level Of Evidence: Level II.