Surgical management of elbow heterotopic ossification: postoperative outcomes with and without continuous passive motion rehabilitation

Background Continuous passive motion (CPM) has been an accepted method of orthopedic postoperative rehabilitation for decades. However, its efficacy remains disputed and there is a paucity of literature looking at the impact of CPM after operative management of elbow heterotopic ossification (HO). This retrospective study aims to compare long-term clinical outcomes after surgical excision of elbow HO between patients with and without postoperative CPM. Methods A retrospective case series was conducted on patients who underwent inpatient surgical excision of elbow HO at an academic level I trauma center between September 1999 and August 2022. Forty-eight patients (51 elbows) were identified, consisting of 16 cases that were rehabilitated with CPM and 35 cases that were not. Long-term follow-up examinations included measurement of elbow flexion–extension and pronosupination arcs, Mayo Elbow Performance Scores, and visual analog scale pain scores. Mann–Whitney U tests were used for statistical analysis. Results Patients had a minimum follow-up of 2 years with an average follow-up of 8 years (range 2-24 years). Utilizing CPM vs. no CPM postoperatively was associated with a significantly greater gain in preoperative to final follow-up flexion–extension arc (100° vs. 50°, P = .003) and a significantly smaller loss in intraoperative to final follow-up flexion–extension arc (0° vs. −15°, P = .018). However, it should be noted that there were no significant differences in the final range of motion based on CPM usage (110° vs. 110°, P = .228). Additionally, patients that utilized CPM reported a significantly greater Mayo Elbow Performance score at final follow-up ( P = .045). Conclusion A CPM rehabilitation regimen after surgical excision of elbow HO may result in improved long-term patient-reported functional outcomes, but further investigation with a prospective, randomized protocol should be pursued.