Abstract
Heterotopic ossification (HO) is characterized by the formation of pathological bone within the soft tissues. HO predominantly affects elbow joints and may be accompanied by tardy ulnar nerve palsy. This study aimed to explore the clinical and functional outcomes of patients with tardy ulnar nerve palsy caused by HO following surgical treatment, with a review of the relevant literature. A retrospective study was conducted on 4 patients with tardy ulnar nerve palsy caused by HO, who underwent anterior subcutaneous ulnar nerve transposition between 2015 and 2020. The patients were followed up for more than 1 year and the cause of HO was also identified. Clinical and functional outcomes were evaluating using the grip strength and pinch strength, visual analog scale (VAS) pain score and Quick disabilities of the arm, shoulder and hand (DASH) score. The causes of HO were repetitive micro-trauma in 1 case and excessive physical or rehabilitation therapy in 3 cases. The average follow-up period was 15.6 months (range; 12-21 months). The grip strength increased from an average of 14kg to 26.5kg. The pinch strength increased from an average of 1.5 kg to 3.63 kg. The Quick DASH score decreased from an average of 55.6 to 6.15. The VAS score for pain decreased from an average of 7 to 0.25. Rapid surgical treatment, including removal of the heterotopic bone and ulnar nerve anterior transposition, might improve outcomes in patients with tardy ulnar nerve palsy caused by HO.