Fixation of Trochanteric Fragments in Cementless Bipolar Hemiarthroplasty of Unstable Intertrochanteric Fracture: Cerclage Wiring

Abstract

Purpose: Bipolar hemiarthroplasty (HA) is an option for the treatment of unstable intertrochanteric fracture in elderly patients. There is a raising concern regarding cable-grip related complications for the fixation of trochanteric fragments. Therefore, the aim of this study was to evaluate outcome of cementless HA with fixation for the trochanteric fragments using monofilament wires in unstable intertrochanteric fracture.

Materials and methods: We reviewed 92 cementless bipolar HAs using a grit-blasted long stem design for unstable intertrochanteric fractures in 91 elderly patients with a mean age of 81.7 years. During the arthroplasty, trochanteric fracture fragments were fixed using 1 or 2 vertical wires and transverse wires. We evaluated the clinical outcomes such as abductor power, ambulatory ability and wire-related complications, and radiologic outcomes including the union of the trochanteric fragment and subsidence of stem.

Results: Sixty-two patients were followed for a minimum of 2 years (mean, 59 months) postoperatively. The mean abductor power and Koval category was 4.1 (range, 3 to 5) and 4.6 (range, 1 to 6). The wire was broken in 3 hips (4.8%) and the nonunion of the greater trochanter occurred in 1 hips (1.6%). Two stems subsided by 3 mm and 8 mm, respectively, during postoperative 6 weeks, after which the subsidence was not progressive.

Conclusion: Cerclage wiring of the trochanter using monofilament wire leads to acceptable outcome in cementless HA for senile patients with unstable intertrochanteric fracture. Cerclage wiring using a monofilament wire is recommended for the fixation of trochanteric fragments.

Keywords: Cementless stem; Hemiarthroplasty; Hip fracture; Wiring technique.

Fig. 1. The Benfix stem is a tapered, rectangular extensive grit-blasted titanium stem with a distal slot.

Fig. 2. Diagram of cerclage wiring technique. Vertical wires were inserted through a hole below adductor tubercle and then passed through abductor insertion portion anteriorly and posteriorly. For lesser trochanter fragments, transverse wires were passed at the level of lesser trochanter.

Fig. 3. (A) An 81-year old woman, who had undergone a hemiarthroplasty for unstable intertrochanteric fracture with Benfix stem and cerclage wires. (B and C) Femoral crack extension occurred intraoperatively, which were treated by cerclage wires. (D) She sustained a periprosthetic fracture at 3 months after a fall from height. (E) On radiograph obtained 3 months after plate fixation.

Fig. 4. (A) An 84-year old woman who had undergone a hemiarthroplasty for unstable intertrochanteric fracture with Benfix stem and cerclage wires. (B) On anteroposterior radiographs obtained 6 weeks postoperatively, the stem was subsided about 8 mm.

Fig. 5. (A) An 89-year old women who had undergone a hemiarthroplasty for unstable intertrochanteric fracture with Benfix stem and cerclage wires. (B) An anteroposterior radiograph obtained 6 years postoperatively shows cortical stress shielding around the stem. However, there is no loosening sign around the femoral stem.