Functional and radiological outcomes of a minimally invasive surgical approach to monostotic fibrous dysplasia

Background: Reports showing high recurrence rates for intralesional curettage and bone grafting have made the current treatment principle for fibrous dysplasia controversial. This study aimed to report the postoperative clinical outcomes from three minimally invasive surgical strategies we use for monostotic fibrous dysplasia (MFD). Patients and methods: Twelve patients with MFD presenting with no pathologic fracture or deformity and treated with one of three surgical strategies-plain open biopsy, plain alpha-tricalcium phosphate (ATP) reconstruction, and prophylactic bridge plating-were included. There were nine men and three women, with median age of 38 years. Mean follow-up was 88 weeks. Five cases involved the proximal femur, two each involved the femoral and tibial diaphyses, and one each involved the distal humerus, radial diaphysis, and proximal tibia. All cases were reviewed for functional and radiological outcomes. Results: Median time to full activity was 1 day (range 1 to 3) for the plain open biopsy group, while the prophylactic bridge-plating and plain ATP reconstruction groups had longer median recovery times (59 days, range 3 to 143, and 52 days, range 11 to 192, respectively). Musculoskeletal Tumor Society scores at last follow-up were excellent for all the cases (mean 29.6, range 25 to 30). Radiological analysis using Gaski et al.' s criteria showed plain open biopsy resulted in partial resolution of proximal femoral lesions, while ATP reconstruction and prophylactic plating resulted in no change and progression in this lesion site, respectively. For femoral diaphyseal lesions, prophylactic plating resulted in partial resolution, while ATP reconstruction resulted in no change. In the tibial diaphysis, prophylactic plating resulted in partial resolution, while plain open biopsy resulted in no change. For the lesions involving the distal humerus and the proximal tibia, plain open biopsy resulted in partial resolution, while for the radial diaphyseal lesion, ATP reconstruction resulted in no change. Radiological progression was limited in 11 (92%) cases, and none had postoperative complications. Conclusion: Plain open biopsies for asymptomatic lesions; prophylactic bridge plating for symptomatic, large diaphyseal lytic lesions; and plain ATP reconstructions for both small and large nondiaphyseal symptomatic lytic lesions may be acceptable alternatives to curettage-incorporating procedures for MFD.