Background: Traumatic hip dislocation results from the dissipation
of a large amount of energy about the hip joint. Clinically, these forces
often are first transmitted through the knee en route to the hip. It is
therefore logical to look for coexistent ipsilateral knee injury in patients
with a traumatic hip dislocation.
Methods: Over a one-year period, we prospectively evaluated the
ipsilateral knee of all patients who had a traumatic hip dislocation on the
basis of a standardized history, physical examination, and magnetic resonance
imaging.
Results: Twenty-one (75%) of the twenty-eight knees were painful.
Twenty-five (89%) of the twenty-eight knees had visible evidence of
soft-tissue injury on inspection. Magnetic resonance imaging revealed evidence
of some abnormality in twenty-five (93%) of twenty-seven knees, with effusion
(37%), bone bruise (33%), and meniscal tear (30%) being the most common
findings.
Conclusions: The present study provides evidence of a high rate of
associated ipsilateral knee injuries in patients with a traumatic hip
dislocation. Bone bruises may provide a plausible explanation for persistent
knee pain following a traumatic hip dislocation. The liberal use of magnetic
resonance imaging is recommended for the evaluation of these patients in order
to detect injuries that may not be discoverable on the basis of a history and
physical examination alone.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.