Comparison of High-tensile Suture and 16-gauge Wire for Prophylactic Fixation in Total Hip Arthroplasty: A Biomechanical Study.

BACKGROUND

Prophylactic cerclage fixation may reduce fracture risk after total hip arthroplasty. Traditionally performed with wire or cables, high-tensile suture is a novel alternative not previously evaluated. This study compared peak torque to failure of cemented and cementless femoral stems using either 16-gauge wire or high-tensile suture in a synthetic femur model.

METHODS

Sixteen collarless triple-taper (TT) stems (8 calcar wire, 8 calcar suture) and 27 taper-slip (TS) stems were tested: 7 each with calcar suture, diaphyseal wire, and diaphyseal suture, and 6 with calcar wire (one excluded). Stems were press-fit or cemented into composite femora. Fixation was applied above the lesser trochanter (calcar) or 2 cm below (diaphyseal). Sutures were tensioned to 80 N. A servohydraulic system applied a 2000 N load with 1°/s internal rotation until failure. Power analysis supported 7 specimens per group to detect a 30 Nm difference. Two-sample and noninferiority t-tests were performed.

RESULTS

For TT stems, peak torque was 92.7 ± 11.4 Nm with calcar wire and 102.6 ± 41.4 Nm with calcar suture; suture was noninferior (P = .038). For TS stems, torque was 148.2 ± 38.6 Nm (calcar wire), 118.3 ± 30.2 Nm (calcar suture), 164.9 ± 21.5 Nm (diaphyseal wire), and 159.4 ± 30.0 Nm (diaphyseal suture). Noninferiority in TS stems was not established. Diaphyseal suture exceeded calcar suture (P = .038).

CONCLUSIONS

High-tensile suture was comparable to wire for calcar fixation in collarless TT stems. In TS stems, noninferiority was not demonstrated. Suture constructs may offer practical advantages and warrant further study.