Traumatic Obturator Hip Dislocation: Injury Characteristics and Clinical Outcomes

TL;DR

This study examines rare obturator hip dislocations, finding they often result from high-energy trauma and are linked to knee and femoral head injuries, but have generally good long-term outcomes.

Contribution

The study provides detailed clinical insights and long-term outcomes for the rare obturator hip dislocation injury.

Findings

Obturator hip dislocations are often associated with knee injuries and femoral head fractures.

Long-term outcomes show minimal limitations and low risk of complications like avascular necrosis or osteoarthritis.

Patient-reported outcome measures indicate good hip function and activity levels post-injury.

Abstract

Purpose

Traumatic hip dislocation into the obturator foramen is poorly understood due to the rarity of the injury. The purpose of this study was to analyze the mechanism of trauma, associated injuries, treatment, and complications in patients who sustained obturator hip dislocation and to evaluate long-term outcomes, including patient-reported outcome measures (PROMs).

Methods

Patient demographics, trauma mechanisms, concomitant injuries, and the treatment of all consecutive patients who sustained an obturator hip dislocation at three level-one trauma centers from 2009 to 2024 were analyzed. At follow-up, the incidence of avascular necrosis (AVN), post-traumatic osteoarthritis (PTOA), further complications, return to work and sports, and PROMs, including Tegner Activity Scale (TAS) and modified Harris Hip Score (mHHS), were recorded.

Results

A total of eight obturator hip dislocations were identified out of 201 traumatic hip dislocations. Associated knee injuries, particularly involving the posterior cruciate ligament (PCL), were observed in five of eight patients (62.5%). Computed tomography (CT) analysis revealed concomitant fractures of the femoral head (Pipkin Types I-IV) or acetabulum in six of eight cases (75%), with the femoral head involved in 50% of all cases. Five patients were followed up (mean 9.17 ± 4.79 years). All patients demonstrated a good or excellent mHHS (mean 85.44 ± 7.36), and the TAS slightly decreased compared to their pre-injury level (5.5 to 4.5). None of the patients had been diagnosed with PTOA or AVN or undergone total hip arthroplasty (THA).

Conclusion

Obturator hip dislocations most commonly result from a high-energy "dashboard injury" and are mainly associated with concomitant femoral head or anterior acetabular wall fractures. Long-term follow-up has shown only minor limitations in activities of daily living, sports, and return to work, with a low risk of femoral head AVN or PTOA.

Figures