Total hip arthroplasty in patients with fibrous dysplasia: a modern update.

Background:Fibrous dysplasia (FD) results from an abnormality in lamellar bone formation and most frequently involves the proximal femur. This can lead to the development of osteoarthritis requiring total hip arthroplasty (THA). Such cases are challenging, and there is a lack of information guiding best management. As such, we devised a study assessing the outcomes and complications in patients with FD undergoing THA with modern implant technology, and we outlined our preferred surgical technique. Methods:A search of our institutional arthroplasty database was performed to identify patients who underwent THA for FD between January 2001 and July 2018 at Mount Sinai Hospital in Toronto, Canada. Data regarding implants used and the use of allograft material or metal augments or both were obtained. Complications and revision requirements were noted. Radiographic and clinical leg length discrepancies were assessed. Results:A total of 10 hips in 9 patients who underwent THA for FD were identified. Mean follow-up time was 6.0 years (range 0.5 to 10.3 yr). The majority of patients underwent THA using uncemented femoral and acetabular components with large femoral heads on highly cross-linked polyethylene liners. Most cases (80% of hips) required allograft to the proximal femur. A single complication requiring revision was noted. In 90% of hip surgeries, the patient required transfusion of packed red blood cells. Mean radiographic and clinical leg length discrepancies were 0.9 cm (range -2.4 to 2.4 cm) and 0.9 cm (range -4 to 0 cm), respectively. Conclusion:Contrary to previous reports, low complication and revision rates were observed with cementless components and routine use of allograft material. The challenging nature of such cases warrants use of an experienced arthroplasty treatment team.