Decoding the behaviour of extracapsular proximal femur fracture- dislocation - A systematic review of a rare fracture pattern

Abstract

Proximal femoral extracapsular fractures with associated ipsilateral hip dislocation is an extremely rare pattern of injury. These fractures may be associated with a spectrum of severity from isolated trochanteric fractures to comminuted intertrochanteric and subtrochanteric fractures with hip dislocation. To date, this pattern of injury is not described in any injury classification system and no clear cut guidelines for the same are available. The aim of this review is to provide an evidence based pooled analysis of the existing literature and develop guidelines that help surgeons tackle this rare injury pattern. Methods: A comprehensive review of the literature was undertaken using the PRISMA. Case reports and series of Extracapsular proximal femoral fracture dislocations published in PubMed, EMBASE, Springer, OvidSP, ScienceDirect, Web of Science and Google scholar between inception of journals to May 2020 were included in the review. A pooled analysis comparing the demography, pattern of the fracture, mode and mechanism of injury with the clinical and radiological outcome and complications was performed. Results: 52 cases from 46 case studies were included in the pooled analysis. There was a near significant association between avascular necrosis and mean time to reduction (p ¼ 0.0865). Individuals with compound injury had 10.12 times higher risk of avascular necrosis (p ¼ 0.009). No significant association between the pattern of proximal femur fracture and incidence of avascular necrosis (p ¼ 0.116, chisquare). There was no significant association between polytrauma and poor clinical outcomes. (p ¼ 0.231). Conclusions: Principles of damage control orthopaedics should be followed in unstable patients with this rare fracture dislocation. Percutaneous Schanz screw reduction manoeuvre can be attempted gently with a low threshold to perform an open reduction. Every attempt at salvaging the fractured hip must be performed in young individuals with an arthroplasty standby for comminuted and unreconstructable cases.