Treatment of periprosthetic femoral fractures with modular stems

Purpose The purpose of this study was to analyse the efficacy of modular femoral stems for the treatment of certain post-operative periprosthetic fractures in patients with hip arthroplasty. Methods Of a total series of 61 modular revision stems, 17 were used to address periprosthetic femoral fractures and 12 of these are the object of this study. The average follow-up was 3.7 years (range 1-14 years). The evaluations were performed at three and six months, and then annually using the HHS score and radiographic studies for the assessment of loosening, subsidence and bone integration of the stem. Results Seven cases had type B2 fractures and five type B3 ones. All patients walked freely, eight of them using canes. HHS improved to a post-operative mean of 78 (range 72-83). Radiographically, fracture healing was observed at three months in nine cases. In six cases stem subsidence of a mean of 3.9 mm (range 2-12 mm) was observed, which stabilized a year following implantation and did not need revision surgery. In two cases a subsequent dislocation (at three and seven months after surgery) occurred, which were treated with constrained acetabular systems. In nine cases hypotrophy of the cortex in the diaphyseal area was noted, which did not alter the patients' clinical course. Conclusion Modular femoral stems are an acceptable treatment in type B2 and B3 periprosthetic fractures.