Modular Fluted Tapered Stems for Periprosthetic Femoral Fractures: Excellent Results in 171 Cases.

ABSTRACT

BACKGROUND: Modular fluted tapered (MFT) stems have advanced treatment of Vancouver B2 and B3 periprosthetic femoral fractures, but series to date have been limited with respect to cohort size and follow-up duration. The purpose of this study was to determine implant survivorship, radiographic results, complications, and clinical outcomes of Vancouver B2 and B3 periprosthetic femoral fractures treated with MFT stems in a large series of patients. METHODS: We identified 171 Vancouver B2 (109) and B3 (62) periprosthetic femoral fractures treated with an MFT stem between 2000 and 2018 using our institutional total joint registry. The mean age was 75 years, 50% were female, and the mean body mass index was 29 kg/m2. The median stem diameter was 18 mm and median stem length was 210 mm. The cumulative incidences of revision and reoperation with death as the competing risk were calculated, radiographs were reviewed, and clinical outcomes were evaluated using the Harris hip score (HHS). The mean follow-up was 5 years. RESULTS: The 10-year cumulative incidence of any revision was 10%. There were 17 revisions, of which only 3 were for the distal fluted portion of the MFT stem. Revision indications included periprosthetic joint infection (PJI) (n = 6) and dislocation (n = 11). The 10-year cumulative incidence of any reoperation was 15%. In addition to the above 17 revisions, there were 7 reoperations for superficial wound complications (n = 4), Vancouver B1 periprosthetic femoral fracture (n = 1), vascular occlusion (n = 1), and acetabular cartilage degeneration requiring an acetabular component (n = 1). Radiographically, there was 1 fracture nonunion. All unrevised MFT stems were radiographically well fixed. Subsidence of ≥5 mm occurred in 11%, but all implants were stable at the most recent follow-up. The mean HHS was 75 at 2 years (n = 71). CONCLUSIONS: In this large series of 171 Vancouver B2 and B3 periprosthetic femoral fractures treated with MFT stems, we found that such constructs were associated with a high rate of fracture healing and provided extremely reliable and durable implant fixation, with no revisions for aseptic loosening. Dislocation and PJI were the most common complications. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.