Surgical resection outcomes of post-traumatic elbow heterotopic ossification: multicenter case series at a minimum 5-year follow-up

Background: Heterotopic ossification (HO), a common complication after elbow trauma, causes severe limb disability. Resection is usually performed for posttraumatic elbow HO (PTEHO) to regain mobility, and although heavily reported, there has been no long-term (minimum, 5-year) follow-up. Methods: A total of 173 patients who underwent PTEHO resection were followed up for a minimum of 5 years in 4 hospitals between January of 2015 and August of 2016. Demographics, disease characteristics, and preoperative and minimum 5-year assessments were collected. After controlling for potential variables when dividing long-term range of motion (ROM) into less than 120 degrees and greater than or equal to 120 degrees, risk factors for ROM recovery to modern functional arc were identified through multivariable regression analysis. Results: Clinically important improvements in ROM from 39 degrees to 124 degrees were obtained at final follow-up, and 74.6% achieved modern functional arc (≥120 degrees). Mayo Elbow Performance Index had clinically important increases from 69 to 93 points at final follow-up, and 96.5% reported excellent to good. Pain (numeric rating scale, from 1.9 to 0.6 points) and ulnar nerve symptoms were improved. The total complication rate was 15.6%, including new-onset ulnar nerve symptoms (5.8%), HO recurrence with clinical symptoms (6.9%), elbow instability (1.7%), and joint infection (1.2%). Previously reported high body mass index ( P = 0.002) and long disease duration ( P = 0.033) were equally identified as risk factors for not achieving modern functional arc; meanwhile, tobacco use ( P = 0.024) and ankylosed HO ( P < 0.001) were found to be new risk factors. Conclusions: Resection yields satisfactory outcomes for PTEHO at long-term follow-up of a minimum of 5 years. High body mass index, tobacco use, long disease duration, and ankylosed HO would negatively affect ROM recovery to a modern functional arc (≥120 degrees). CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.