Systematic Review and Meta-Analysis of Avascular Necrosis and Posttraumatic Arthritis After Traumatic Hip Dislocation

Objectives:To determine the incidence rate and associative factors for the development of avascular necrosis (AVN) and posttraumatic arthritis (PTA) after traumatic hip dislocation and time to reduction.Data Sources:A comprehensive search of databases including PubMed, Cochrane Database, and Embase through April 2014 for English articles reporting complications of AVN and PTA after hip dislocation was performed.Study Selection:Inclusion criteria were English-only studies, a patient population of adults, study outcomes of AVN and/or PTA reported, and articles reported at least type I dislocations.Data Extraction:Two authors independently extracted data from the selected studies and the data collected were compared to verify agreement.Data Synthesis:Random-effects models were used for meta-analysis. The overall event rate of AVN and PTA was calculated and stratified based on Thompson-Epstein of the hip dislocation. Odds ratios were calculated for those articles that reported rates of AVN based on time to reduction.Conclusions:For anterior dislocations, the event rate for AVN ranged from 0.087 to 0.333, whereas the event rate for PTA ranged from 0.125 to 0.700. Analysis of posterior dislocations revealed that the event rate for AVN ranged from 0.106 to 0.430; additionally, the event rate for PTA ranged from 0.194 to 0.586. For posterior hip dislocations and type I and II anterior dislocations, the severity of the injury correlates with an increase in the development of AVN and PTA. The odds ratio of AVN for those hip dislocations reduced after 12 hours versus those reduced before 12 hours was 5.627.Level of Evidence:Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.