Protrusio acetabuli

Protrusio acetabuli describes a condition where the medial wall of the acetabulum, the socket of the hip joint, protrudes excessively into the pelvic cavity. This anatomical abnormality can lead to impingement, pain, and degenerative changes within the hip joint. It is often associated with restricted range of motion and can be a precursor to osteoarthritis.

This code is used when documentation clearly indicates an inward bulging or protrusion of the acetabulum. It is typically diagnosed radiographically, often identified on X-rays, CT scans, or MRI of the pelvis or hip. Use this code when the physician explicitly states "protrusio acetabuli" or describes the characteristic radiographic findings.

• Differentiate from coxa profunda, which is a deeper acetabular socket but without the medial wall protruding past the ilioischial line.
• Specify laterality (left, right, or bilateral) using the appropriate seventh character or associated laterality codes if available for the specific encounter.
• Look for associated conditions such as osteoarthritis of the hip, which may require additional coding.