Impact of immobilization period and anterior capsular injury on flexion contracture in distal humerus coronal shear fractures.

Background: Simple elbow dislocations exhibit residual flexion contracture after long-term immobilization. However, the factors affecting flexion contracture after fixation of distal humerus coronal shear (DHCS) fracture remain unclear.

Methods: This study enrolled 21 elbows in DHCS fracture (group A) from 2007 to 2017 and 30 elbows in elbow dislocation (group B) in 2020, all of whom attended a single trauma center. Group A was divided by immobilization period into less than 3 weeks (A1) and more than 3 weeks (A2). Injury patterns of the anterior capsule were divided into proximal stripping, middle displaced, and distal avulsion on magnetic resonance imaging (MRI) scans. Range of motion and functional outcomes were compared between groups A1 and A2.

Results: All patients in group A exhibited proximal stripping of the anterior capsule, while group B showed middle displaced (37%) and distal avulsion (63%) injuries (P<0.001). The mean flexion contracture was 2° in A1 and 8° in A2 (P=0.139), demonstrating no significant difference by immobilization duration. Similarly, the groups had no significant differences in Mayo Elbow Performance Score (MEPS) or Disabilities of the Arm, Shoulder and Hand (DASH) scores.

Conclusions: Flexion contracture following elbow trauma appears to be more closely related to the pattern of anterior capsule injury than the duration of immobilization. Early identification of anterior capsule injury patterns via MRI could inform treatment decisions, particularly in cases where stable surgical fixation is challenging. Prolonged immobilization may be a viable adjuvant treatment option in such cases. Level of evidence: III.