Hip Instability following DHS Fixation Surgery for Unstable Four Part Per-Trochanteric Fracture Femur

Abstract

Background: In an ageing population, with resultant osteoporosis hip fractures are common indication for per-trochanteric fracture hip repairs. Various modalities of surgical treatment basically emphasis fracture reduction, fracture immobilization, and rehabilitation as a guide to treatment. Subluxation or dislocation following operative treatment of four part unstable per-trochanteric fracture with Sliding Hip Screw is rare and occasional cases have been reported. Material and Methods: An observational prospective study carried out at tertiary care hospital from Jan 1997 – Dec 2014. Our operative experience of total 510 patients of which 480 underwent DHS fixation surgery for unstable four part per-trochanteric fracture showed 6 cases of instability as subluxation and dislocation. Results: We report 6 cases out of 480 DHS fixation showing instability in 3 cases and subluxation and dislocation in 3 cases after 6 weeks of follow-up. These patients were offered arthroplasty and the follow-up results were evaluated after 8 months. Among 6 cases, four had instability after six weeks and remaining two developed dislocation after eight months which were associated with infection. 1 patient refused further investigations & treatment, 3 other died with due course of time, 1 lost to follow -up and One patient with infection underwent excision arthroplasty. Conclusion: Hip instability following DHS fixation surgery for four part Per-trochanteric fracture femur is a rare complication. Cause of this complication could be mechanical factors (excessive collapse, rotational torque) and infection (superficial or deep) may serve as a contributing factor. Diagnosis was done mainly on the basis of clinical examination and investigations such as X-rays, USG and blood tests. Treatment for such complications consists of Hip arthroplasty. These complications can be prevented with the use of TFN or cemented bipolar prosthesis primarily for treating these type of fractures. Keywords: Intertrochanteric fracture, hip instability, surgical fixation