Risk factors associated with complications following total hip arthroplasty using the two-incision technique

Background: The frequency of the complications following total hip arthroplasty (THA) using the two-incision technique is well documented. However, few reports have analyzed the preoperative patient-related factors associated with the complications. The purpose of this study was to estimate the incidence of early complications following primary two-incision THA and to define the risk factors associated with perioperative complications. Materials and Methods: The subjects of this retrospective study were 1218 consecutive patients who underwent primary two-incision THA. The incidence of hip dislocation, stem subsidence, intraoperative femoral fracture, and nontraumatic postoperative femoral fracture was evaluated. The association between complications and preoperative patient-related factors, including gender, obesity, Crowe classification, age, body mass index (BMI), and morphological parameters of the proximal femoral medullary cavity, were investigated. Results: The incidences of complications were dislocation (1.1%), stem subsidence (0.9%), intraoperative femoral fracture (1.2%), and postoperative femoral fracture (0.7%). Obesity (BMI > 30) influenced the occurrences of stem subsidence and postoperative femoral fractures (p = 0.0001, p = 0.019). Crowe classification significantly correlated with intraoperative femoral fractures (Grade II: odds ratio (OR) 4.63, 95% confidence interval (CI), 1.32-15.6; Grade III and IV: OR 8.96, 95% CI, 2.2-34.94). Additionally, the outer diameter of the femur 10 cm below the lesser trochanter tended to be small in patients who developed a femoral fracture. Conclusions: The early complication rate was comparable to other methods used in uncemented THA. It is necessary for patients with risk factors revealed in this study to pay careful attention or consider other surgical approaches to avoid complications. Further studies considering femur morphology are required.