gms | German Medical Science

Objectives: Megaprosthetic limb salvage remains a complex procedure in a high-risk group with increasing potential for postoperative complications. Periprosthetic fractures after megaprosthetic reconstructions have been reported, but with limited literature on this topic. In this study we share our center's experience in the management of these fractures detailing epidemiology, treatment strategies and outcomes and hence to some degree addressing the existing knowledge gap on this Topic.

Methods: We reviewed our centre's limb salvage surgery database (1996-2013) and identified 31 patients with megaprosthetic reconstructions that were complicated by periprosthetic fractures. Data of interest such as patient demographics, fracture details, management strategies and outcomes was extracted from the database. Details specific to periprosthetic fracture management included time to fracture, type, site, mechanism, treatment strategy, intraoperative bone loss, joint loss, complications and bone healing status. Fracture severity was graded via Lewis and Rorabeck classification. For analysis, treatment strategies were distribution according to fracture grades to assess impact of fracture severity on management. Chi square and odd ratios was used to determine significant associations.

Results: Mean age of our cohort at the time of diagnosis was 38.5 years (10 to 82 years). Of the 31 cases, 27 (87%) cases were primary bone tumors while 4 cases were metastatic lesions. Following the initial limb salvage reconstruction most cases received some form of adjuvant therapy (27 (87%) CTX, 10 RTX). The femur was the most common fractured bone (17, 54.8%) followed by tibia (9, 29%) and humerus (5). Type III fracture was seen in 38.7%. Mean time to fracture was 34.5 months (range 9 months - 18 years). Barring four cases, all fractures were surgically managed. Amputation (2, 6.5%), ORIF (5, 16%), revision preserving the adjacent joint (15, 48.4%) and implant elongation replacing the adjacent joint (5, 16%) were performed. There was a clear trend towards revision and replacement in fractures that occurred after 2 years. All five replacement cases were in patients with a displaced fracture and prosthetic loosening. In univariate analysis this fracture profile was also a risk factor for higher intraop bone loss (OR 7.5, p=0.011). Seven (22.5%) patients suffered an adjacent joint loss during management of their fractures, with local tumor progression being a risk factor (OR 57.7, p =0.001). Patients FU was in average 44 months after fracture. Complications were noted in 11 (35%) cases, including recurrent fracture, infection and loosening.

Conclusion: Management of periprosthetic fractures following megaprosthetic reconstruction is demanding with a high risk for complications. Treatment strategy should take into consideration important predictors such as fracture profile, tumor progression, time to fracture and bone stock adequacy.