Background
Although the direct lateral approach to the hip gives excellent exposure of the hip joint and a clear operating field, this approach creates a potential functional risk for the abductor musculature by damaging the superior gluteal nerve or inadequate reinsertion of the musculotendinous cuff into the greater trochanter. The present study investigates the incidence of clinical and electrophysiological evidence of damage to the superior gluteal nerve after this approach.
Objective
The aim of this study was to evaluate the role of needle EMG in the assessment of hip abductors function following lateral approach of the hip.
Patients and Methods
Sixty cases were subjected to Hardinge lateral approach in the department of orthopedic surgery and traumatology, Menoufia University Hospital from March 2014 to March 2016. Hemiarthroplasty, after a fracture of the neck of the femur, was performed in 30 patients and total hip replacement for advanced osteoarthritis of the hip joint in 30 patients. After operation all patients were assessed clinically and electrophysiologically.
Results
In base line EMG performed three weeks postoperatively to all patients, 18 patients (30%) showed EMG evidence of acute denervation of hip abductors while the remaining 42 patients (70%) showed normal EMG studies.
Conclusion
EMG detection of superior gluteal nerve injury was frequent in lateral approach to the hip. The injury recovered spontaneously within 3 months post-operatively. Good surgical technique and awareness of the anatomy of the nerve supply are the key factors in preserving good abductor strength.