Clinical outcomes and return to sports following medial malleolar stress fractures in adolescent athletes.

Abstract

Medial malleolar stress fractures (MMSF) are relatively rare and classified as a high-risk fracture progressing to a complete fracture. The purpose of this study was to describe the clinical outcome of conservative and surgical treatments for MMSF in adolescent athletes. Twenty MMSF in 19 athletes (mean age 15.6 ± 2.0 years) were analyzed retrospectively. MMSF were categorized into four stages (I) no visible fracture lines based on radiograph and only confirmed high signal intensity on MRI (II) incomplete fracture on radiograph (III) complete and non-displacement fracture on radiograph, and (IV) displaced fracture on radiograph. The time required for radiographic bone union and return to sports (RTS) was evaluated. Seven fractures were categorized as stage I, 5 were stage II, 2 were stage III, and 6 were stage IV. Radiographic union (Stage II-IV) did not differ among stages (p = 0.696). RTS differed significantly according to stage (p < 0.010), with Stage I achieving earlier RTS than Stage II (p = 0.018). Stage I lesions were successfully treated conservatively, whereas 76.9% of Stage II or higher lesions ultimately required surgical fixation. In adolescent athletes with MMSF, clinical outcomes were strongly associated with fracture stage. Stage I responded well to conservative treatment and achieved early RTS, whereas Stage II or higher frequently required surgical treatment. Early MRI evaluation may facilitate timely diagnosis and help guide stage-based treatment decisions in this population.