Atraumatic Anterior Dislocation of the Hip Joint

Area of Science:

• Orthopedics
• Radiology

Background:

• Hip dislocation typically results from high-energy trauma.
• Posterior dislocations are more common than anterior ones.
• Atraumatic anterior hip dislocation is exceptionally rare.

Purpose of the Study:

• To present a rare case of atraumatic anterior hip dislocation.
• To explore potential contributing factors in a daily living activity-induced dislocation.
• To evaluate the utility of tomosynthesis in elucidating the dislocation mechanism.

Main Methods:

• Case report of atraumatic anterior hip dislocation.
• Analysis of contributing factors including developmental dysplasia of the hip and postural changes.
• Measurement of acetabular anterior coverage in the sagittal plane using a tomosynthesis imaging system.

Main Results:

• An atraumatic anterior hip dislocation occurred during a daily activity.
• Contributing factors identified: anterior capsule insufficiency (developmental dysplasia), posterior pelvic tilt (vertebral fracture-induced kyphosis), and postural acetabular coverage changes.
• Tomosynthesis imaging system effectively demonstrated acetabular anterior coverage changes.

Conclusions:

• Atraumatic anterior hip dislocation can be precipitated by daily activities in predisposed individuals.
• A combination of anatomical and postural factors can lead to hip instability.
• Tomosynthesis is a valuable tool for assessing acetabular morphology and understanding dislocation mechanisms.