Reconsidering uniform treatment: magnetic resonance imaging-based insights into the multiform pathophysiology of sprained ankles

Abstract

Ankle sprains are among the most common musculoskeletal injuries, yet their clinical complexity is often underestimated. The relationship between ankle sprains and bone bruises in both the ankle joint and midfoot remains underexplored. At our institution, patients with moderate to severe ankle sprains routinely undergo magnetic resonance imaging (MRI) and receive conservative treatment with a short leg posterior cast splint. This study specifically focused on bone involvement assessed by MRI, rather than soft tissue or functional parameters. We retrospectively reviewed MRI scans of 70 patients with acute moderate (Grade 2) to severe (Grade 3) ankle sprains who presented consecutively between November 2014 and December 2019. Patients with mild sprains (Grade 1) were excluded. Bone bruises were assessed, and all patients were treated with a short leg posterior cast splint extending from the lower leg to the forefoot. Crutches were prescribed when pain persisted during weight-bearing after splint application. Multivariable logistic regression analysis was performed to evaluate the associations between MRI-detected bone bruises and crutch use following fixation. The fixation period, available in 63 patients, ranged from 8 to 72 days (mean: 29.5 days). Walking pain requiring crutches, used as a proxy indicator of persistent weight-bearing pain rather than a validated clinical outcome, was observed in 32 /70 (45.7%) of patients. All patients experienced resolution of ankle joint pain following treatment. MRI revealed bone bruises in the ankle and midfoot in 57/70 (81.4%) of cases. Midfoot involvement, including the tarsal bones and Chopart joint, was present in 24/70 (34.3%) of cases. The talus was the most frequently affected bone 42/70 (60.0%), followed by the tibia 31/70 (44.3%), tarsal bones 18/70 (25.7%), and calcaneus 15/70 (21.4%). Bone bruises on the talocrural joint surface of the talus were significantly associated with crutch use after fixation (P = 0.041). Multivariable logistic regression analysis identified both younger age (odds ratio [OR] 0.957, 95% confidence Interval [CI] 0.930–0.985, P = 0.003) and bone bruises on the talocrural joint surface of the talus (OR 4.012, 95% CI 1.174–13.713, P = 0.027) as independent predictors of crutch use after fixation. All patients reported resolution of ankle joint pain by the final follow-up, with no persistent or recurrent symptoms documented during the observation period. Bone bruises in the ankle and midfoot are frequently associated with moderate to severe ankle sprains. MRI findings indicate a multifaceted pathophysiology, underscoring the importance of individualized treatment strategies. In cases where bone bruises are present on the talocrural joint surface, midfoot immobilization and a temporary period of non–weight-bearing may be appropriate considerations.