Predictors of revision following internal fixation of intracapsular hip fractures

Introduction

Intracapsular hip fractures in young adults are treated with internal fixation, often as a surgical emergency to reduce the vascular insult to the femoral head. Avascular necrosis and non-union often require revision surgery.

Methods

A prospective trauma database was retrospectively searched from 1^st August 2008 to 31^st December 2010. Intracapsular hip fracture admissions to the Regional Trauma Centre, in adults under sixty-five years, were studied.

Ninety-eight intracapsular fractures internally fixed with sliding hip screw underwent radiographic review for quality of fixation, and evidence of complications at a mean of thirteen months. Co-morbid medical conditions and quality of fixation were assessed for association with revision rates.

Results

Avascular necrosis developed in eighteen fractures, and seven proceeded to non-union. Seventeen of ninety-eight fractures underwent revision to total hip arthroplasty. Three individuals were deceased at final review.

Six of thirty-four fractures (18%) fixed within twelve hours of injury required revision, compared with eleven of sixty-four (17%) fixed after twelve hours. None of the four fractures fixed within six hours required revision, although this was not statistically significant (p=0.32). Revision was required for three of six individuals with chronic respiratory disease (50%) excluding asthma, one of two with rheumatoid arthritis (50%), and three of six with varus reduction (50%), and each were significant on multiple regression. Residual translation and eccentric screw placement approached significance on chi-squared analysis. Only two of twenty (10%) fractures fixed using an additional anti-rotation screw required revision.

Conclusions

Internal fixation of intracapsular hip fractures within twelve hours in young adults did not statistically reduce revision rates. Accurate reduction and internal fixation is paramount, and anti-rotation screws may reduce complication rates. Certain co-morbid conditions predict revision, and should be taken into consideration when selecting the primary operative procedure.