Resection of neurogenic heterotopic ossification (NHO) of the hip, lessons learned after 377 procedures

Introduction/Background Neurogenic heterotopic ossification (NHO) of the hip is secondary to neurologic lesions such as cranial trauma, stroke, medullary injury or cerebral anoxia. Our practice of heterotopic ossification surgery has progressed during our experience, becoming better adapted to the pathology and to the patients, who are often fragile and show neurologic sequelae. We want to give a feedback of the lessons we learned in the Raymond-Poincare Hospital about NHO resection. Material and method In total, 377 first-line procedures were performed for heterotopic ossification of the hip between 1993 and November 2016. Surgery requires rigorous organization and planning, preferably in a rehabilitation department, by a multidisciplinary team experienced in this pathology. Preoperative work-up should include contrast-enhanced CT; scintigraphy is non-contributive. Indications for surgery are decided in a multidisciplinary team meeting, with a contract laying out expected functional gain. It is this contract that determines the extent of resection, without seeking complete resection, which would incur an increased risk of complications. Results The surgical approach and resection strategy depend on lesion location and any resulting neurovascular compression. In our own series, 3,5% of patients required revision for recurrence. The most common complications is infection: 10.3% in our experience, with wide variation according to location. No adjuvant treatments have demonstrated efficacy against recurrence. Conclusion Surgical treatment of heterotopic ossification of the hip is reliable when performed in an adapted center by an experienced multidisciplinary team. Clinical results are satisfactory. There remains, however, a risk of sepsis, especially with medullary injuries.