Objectives: The objective was to report the ability of a magnetic resonance image to document the integrity of the obturator externus tendon after posterior hip dislocation as a potential predictor for preserved femoral head vascularity.
Design: Retrospective radiographic and clinical pilot study.
Setting: Level I trauma center.
Patients/Participants: Nineteen consecutive patients with traumatic posterior hip dislocation.
Outcome Evaluation: Intraoperative correlation of soft tissue damage and radiographic assessment of avascular necrosis of the femoral head 3 years postinjury.
Methods: Magnetic resonance imaging performed in the acute phase of posterior hip dislocation. Correlation with intraoperative findings during surgical hip dislocation and with avascular necrosis 3 years postinjury.
Results: The obturator externus tendon was intact in all cases with preserved femoral head vascularity. After a 3-year follow up, there were no cases of avascular necrosis.
Conclusion: In this small series of patients, posterior hip dislocation did not imply a tear of the obturator externus muscle. An intact obturator externus tendon suggests preservation of the deep branch of the medial femoral circumflex artery to the femoral head.
From the Departments of *Orthopedic Surgery; †Diagnostic Radiology, Inselspital, University of Bern, Bern, Switzerland; ‡Department of Radiology, Qatar Orthopedic and Sports Medicine Hospital, Qatar; and §Department of Radiology, University of Notre Dame, Sydney, Australia.
Accepted for publication February 3, 2010.
The authors report no financial disclosures.
Reprints: Moritz Tannast, MD, Department of Orthopaedic Surgery, Inselspital, University of Bern, Switzerland (e-mail: firstname.lastname@example.org).