Effectiveness of shape memory alloy embracing device in treatment of Vancouver B2 periprosthetic femoral fracture

Abstract

To analyze the effectiveness of shape memory alloy embracing device in the treatment of Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty. The clinical data of 30 patients (30 hips) with Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty between January 2019 and January 2021 were analyzed retrospectively. Among them, 15 cases were treated with shape memory alloy embracing device for fracture fixation (group A) and 15 cases with titanium cable cerclage (group B). There was no significant difference in general data such as gender, age, body mass index, the cause of primary arthroplasty and surgical method, prosthesis type, the cause and side of femoral fracture, the time from injury to operation, and comorbidities between the two groups ( P>0.05). The operation time, intraoperative blood loss, and hospital stay of the two groups were recorded. The fracture healing was examined by X-ray film, and the hip joint function was evaluated by Harris score. The operations in both groups were completed successfully, and the incisions healed by first intention after operation with no vascular or nerve injury. The operation time and hospital stay in group A were significantly shorter than those in group B ( P<0.05), but there was no significant difference in intraoperative blood loss between group A and group B ( t=-0.518， P=0.609). Patients were followed up 12-20 months (mean, 16.3 months) in group A and 12-22 months (mean, 16.7 months) in group B. X-ray film showed that all fractures healed, the healing time was (14.73±2.05) weeks in group A and (17.27±2.60) weeks in group B, and there was a significant difference between the two groups ( t=-2.960， P=0.006). During follow-up, there was no complication such as prosthesis loosening, periprosthetic infection, joint stiffness, or internal fixator loosening. The Harris score of group A was significantly better than that of group B at 3, 6, and 12 months after operation ( P<0.05). Compared with titanium cable cerclage, using shape memory alloy embracing device to fix Vancouver B2 periprosthetic femoral fracture can accelerate fracture healing, shorten operation time, and reduce intraoperative blood loss. Patients can perform functional exercise earlier and restore joint function better.