A Consecutive Series of Vancouver B2 Periprosthetic Femur Fractures Treated With Contemporary Monoblock Versus Modular Revision Stems: Clinical and Radiographic Outcomes.

INTRODUCTION: Tapered fluted titanium (TFT) stems are the implant design of choice for managing Vancouver B2 periprosthetic femur fractures (PFFs), producing reliable results over the past few decades. The aim of this study was to compare the radiographic and clinical outcomes of Vancouver B2 PFFs treated with contemporary monoblock versus modular TFTs.

METHODS: A consecutive series of 113 patients (72 women, 64%, mean age 70 years (range, 26 to 96)) who had a B2 PFF were treated with either a monoblock (n = 42) or modular (n = 71) TFT stem between 2008 and 2021. The mean body mass index was 30 ± 7. The mean follow-up was 2.9 years. A radiographic review was performed to assess leg length and offset restoration, endosteal cortical contact length, and stem subsidence. Kaplan-Meier analyses were used to determine survivorship without revision, reoperation, or dislocation.

RESULTS: There was no difference in the restoration of leg length (0.3 ± 8.0 mm) or offset (2.8 ± 8.2 mm) between the monoblock and modular cohorts (P > 0.05). Mean endosteal cortical contact length (47.2 ± 26.6 versus 46.7 ±2 6.4 mm, P = 0.89) and stem subsidence (2.7 ± 3.5 versus 2.4 ± 3.2 mm, P = 0.66) did not differ. No difference in PROMs (Hip Disability and Osteoarthritis Outcome Score-Joint Replacement (HOOS, JR); Veterans RAND 12 Item Health Survey (VR12) Physical and Mental; Visual Analog Score (VAS) and Lower Extremity Activity Scale (LEAS)) between the groups was observed. Survivorship at 2 years free from reoperation, revision, and dislocation was 90.4, 90.3, and 97.6%, respectively, for the monoblock cohort; and 84.0, 86.9, and 90.0%, respectively, for the modular cohort.

CONCLUSION: No significant differences in radiographic or clinical outcomes were observed between patients treated with monoblock or modular TFTs in this large series of B2 PFFs.