Comparison of post-operative muscular strength between gamma nailing and hemiarthroplasty system in femoral intertrochanteric fractures

Abstract The current study focuses on the comparison of postoperative muscular strength around the hip joint of patients with femoral intertrochanteric fractures treated either by cephalo-medullary (CM) nailing or a new bipolar hip prosthesis (BHP), an especially attached device to secure displaced greater trochanteric fragment. Twenty patients treated with CM nailing were age- and sex- matched with a control group of 20 patients treated with BHP. Maximum isometric forces at the bilateral hip joint were measured during the follow up period. Means of 3 measurements were represented. The mean and standard deviation values (kg) of muscle strength at the non-operative/ operative side in the CM nailing group were as follows: flexion strength 9.5±4.7/8.5±4.9 (P=0.06), extension strength 6.2±3.5/5.5±3.7 (P=0.08), abduction strength at 0 degrees 7.7±3.5/6.2±2.8 (p=0.002), abduction strength at 10 degrees 5.5±2.0/4.2±2.0 (p=0.001). In the BHP group, mean and standard deviation values of muscle strength at the non-operative/ operative side were as follows: flexion strength 6.5±2.8/6.0±3.4 (P=0.08), extension strength 4.4±0.9/4.4±0.6 (P=0.83), abduction strength at 0 degrees 5.1±1.9/5.0±1.6 (p=0.12), and that at 10 degrees 4.7±1.4/4.6±1.3 (p=0.10). Our results demonstrate that CM nailing may cause a 25-30% decrease in postoperative muscle strength around the hip joint, particularly during hip abduction. With the new BHP, greater trochanter reduction is achieved allowing early weight bearing and maintaining strength in abduction. Surgeons should consider postoperative muscular strength as one of the necessary factors for selection of the appropriate surgical procedure. Therapeutic Level III.