Objective: To evaluate risk factors for femoral fracture after porous-coated cementless total hip arthroplasty (THA).
Study design: Case series.
Animals: Dogs (n=74) that had cementless THA (n=84).
Methods: Medical records of dogs from 2 referral hospitals were reviewed for occurrence of postoperative femoral fracture. Patient and operative (age, breed, sex, weight, and canal flare index [CFI], indication for arthroplasty, intraoperative fissure, cerclage usage, and implant sizes) factors were analyzed. Assessment of implant positioning and canal fill was performed on immediate postoperative radiographs. Femoral fractures (n=11) were evaluated and compared with 73 cases without fracture that met the inclusion criteria.
Results: Mean (+/-SEM) age was 7.30+/-0.69 years for dogs with, and 4.77+/-0.37 years for dogs without femoral fracture. Age was positively associated with fracture (P=.022). Mean (+/-SEM) CFI was 1.80+/-0.09 for dogs with, and 1.98+/-0.04 for dogs without fracture. CFI was negatively associated with fracture (P=.045). Body weight, intraoperative fissure, cerclage use, implant size, position, and canal fill did not influence the occurrence of femoral fracture.
Conclusions: Older dogs and dogs with lower CFI may be at increased risk for femoral fracture after porous-coated cementless THA.
Clinical relevance: Risk factors exist for femoral fracture after cementless THA using porous-coated implants, and should be critically evaluated during the patient selection. These risks should be weighed against the benefits of the system, and measures to minimize femoral fracture in at-risk patients studied.