Comparison of elbow contracture release in elbows with and without heterotopic ossification restricting motion

We compared 16 patients with post-traumatic heterotopic ossification (HO) restricting elbow motion (but not complete bony ankylosis) after elbow trauma with 21 patients with capsular contracture alone to test the hypothesis that HO is associated with diminished motion after release. Patients with burns or head injury were excluded. The preoperative flexion arc averaged 59 degrees in the HO cohort and 52 degrees in the capsular contracture cohort. The mean flexion arc after the index surgery improved by 54 degrees to a mean arc of 113 degrees in the HO cohort and by 35 degrees to a mean of 87 degrees in the capsular contracture cohort (P = .02). After all subsequent procedures (including procedures to address residual stiffness in 1 patient in the HO cohort and 4 patients in the capsular contracture cohort), the flexion arc averaged 116 degrees in the HO cohort and 98 degrees in the capsular contracture cohort (P = .19). Open release of post-traumatic elbow stiffness is more effective when HO hindering motion is removed than when there is capsular contracture alone.