What is calcification of the hip labrum?

Calcification of the Hip Labrum: Diagnosis and Management

Calcification of the hip labrum is a condition characterized by calcium deposits within the fibrocartilaginous acetabular labrum, which can cause hip pain, limited range of motion, and contribute to hip joint degeneration.

Definition and Prevalence

• Labral calcification is the deposition of calcium crystals (typically calcium pyrophosphate dihydrate) within the fibrocartilaginous acetabular labrum of the hip 1
• The prevalence of calcification in the acetabular labrum is remarkably high, with studies showing 100% prevalence in specimens from patients with end-stage osteoarthritis 1, 2
• The amount of calcification in the acetabular labrum is typically higher than that found in the articular cartilage of the hip (approximately 3 times greater) 1

Clinical Presentation

• Patients with symptomatic labral calcification typically present with anterior groin pain 3
• Limited range of motion and positive impingement signs are common clinical findings 4, 3
• Symptoms may persist for months before diagnosis, with an average duration of 7.5 months in one study 4
• Hip pain severity correlates with the degree of labral calcification, independent of age and histological degeneration 2

Diagnostic Imaging

• Radiography should be the initial imaging method for evaluating hip pain and can detect calcifications in the area of the acetabular roof 5, 6
• MR arthrography is considered the gold standard for confirming and characterizing labral tears and associated calcifications, with a rating of 9/9 (usually appropriate) according to ACR Appropriateness Criteria 5, 7
• CT arthrography is an alternative with a rating of 7/9 (usually appropriate) if MR arthrography is contraindicated 7
• On radiographs, labral calcifications typically appear as increased opacity compared to neighboring trabecular bone, often with clear separation from the acetabular rim 3

Pathophysiology and Association with Hip Pathology

• Labral calcification strongly correlates with histological degeneration of both the labrum (Krenn score) and the articular cartilage (OARSI score), independent of age 1
• Most patients with symptomatic labral calcification also have femoroacetabular impingement (FAI) 3
• Calcification is most commonly found in the anterosuperior labrum, accessible from the capsule-labral recess 3
• The condition has been described as "calcifying labrumitis" when calcification is accompanied by surrounding inflammation 4

Treatment Options

Conservative Management

• Diagnostic intra-articular anesthetic and corticosteroid injections can serve both diagnostic and therapeutic purposes 5, 8
• Non-steroidal anti-inflammatory medications can be used to manage pain and inflammation 8

Surgical Management

• Arthroscopic removal of calcific deposits is the recommended treatment for symptomatic labral calcification that fails conservative management, as it is minimally invasive and effective 6, 4
• After removal of calcification, the labrum can be either repaired with suture anchors or partially resected, depending on the extent of damage 4
• For associated small delaminated cartilage lesions (<3 cm²), debridement followed by microfracture may be indicated 5, 8
• Larger associated cartilage lesions (>3 cm²) require more complex management approaches 5

Outcomes

• Studies report significant improvement in pain and function following arthroscopic treatment of labral calcification 6, 4
• In one study, all patients were symptom-free with painless full range of motion at 4-month follow-up after arthroscopic removal of calcific deposits 6
• Another study reported 100% satisfaction rate with significant improvements in Visual Analogue Scale (VAS), modified Harris Hip Score (mHHS), and Nonarthritic Hip Score (NAHS) 4

Clinical Considerations and Pitfalls

• Labral calcification should be distinguished from os acetabuli, which has different clinical implications 3
• The presence of labral calcification should raise suspicion for femoroacetabular impingement, which often coexists 3
• Untreated labral calcification may lead to persistent pain, progressive cartilage damage, and potential development of osteoarthritis 8, 1
• Arthroscopic treatment is particularly recommended for young, active patients without signs of hip osteoarthritis 6

Monitoring and Follow-up

• Regular monitoring for symptom recurrence or progression is advised, as chondromalacia may progress to osteoarthritis if not properly managed 8
• A structured rehabilitation protocol is essential following either conservative or surgical intervention 8