|Classification and external resources|
Right sided Protrusio acetabuli
Protrusio acetabuli is an uncommon defect of the acetabulum. The acetabulum is the socket that receives the femoral head to make the hip joint. The hip bone of the pelvic bone/girdle is composed of three bones, the ilium, the ischium and the pubis. In protrusio deformity, there is medial displacement of the femoral head in that the medial aspect of the femoral cortex is medial to the ilioischial line. The socket is too deep and may protrude into the pelvis. 
Protrusio acetabuli is divided into two types, primary and secondary.
Primary protrusio acetabuli
- Characterized by progressive protrusio in middle aged women
- May be associated with OA
- May be familial
Secondary protrusio acetabuli
- Femoral head prosthesis
- Cup arthroplasty
- Septic arthritis
- Central fracture dislocation
- Total hip replacement surgery
Protrusio acetabuli may also be thought of as unilateral or bilateral.
Unilateraly protrusio acetabuli
- Tuberculous arthritis
- Fibrous dysplasia
Bilateral protrusio acetabuli
- Rheumatoid arthritis
- Paget disease
(Source Dahnert's Radiology)
Signs and Symptoms
- May be asymptomatic
- Limitation of joint range of movement is the earliest sign
The protrusio may progress until the femoral neck impinges against the pelvis.
Arthroscopic surgery (or open joint surgery) is an effective treatment. Joint replacement surgery may be necessary in the case of severe pain or substantial joint restriction. Prominent trabeculae. * Normal sacro-iliac joints and symphysis pubis.
- Van De Velde S, Fillman R, Yandow S (2006). "The aetiology of protrusio acetabuli. Literature review from 1824 to 2006". Acta Orthop Belg 72 (5): 524–9. PMID 17152413.
- Van de Velde S, Fillman R, Yandow S (2006). "Protrusio acetabuli in Marfan syndrome. History, diagnosis, and treatment". J Bone Joint Surg Am 88 (3): 639–46. doi:10.2106/JBJS.E.00567. PMID 16510833.
- McBride MT, Muldoon MP, Santore RF, Trousdale RT, Wenger DR (2001). "Protrusio acetabuli: diagnosis and treatment". J Am Acad Orthop Surg 9 (2): 79–88. PMID 11281632.