Hip Labral Tears

Hip labral tears predominantly occur in the anterosuperior location (85%) and are most commonly associated with femoroacetabular impingement (FAI)—cam morphology causes outside-in delamination at the labral-chondral junction. The acetabular labrum serves critical functions: it increases acetabular depth by 22% and surface area by 28%, creates a suction seal to contain joint fluid, and provides proprioceptive feedback through free nerve endings. Clinical diagnosis relies on the FADIR test (flexion, adduction, internal rotation reproducing anterior impingement pain), with MR arthrography serving as the gold standard imaging modality. Surgical management favors labral repair over debridement, as multiple studies demonstrate superior functional outcomes when the labrum is preserved. Critically, underlying morphologic abnormalities (FAI, dysplasia) must be addressed concurrently—treating the labral tear in isolation without correcting the bony pathology leads to predictable failure.

The acetabular labrum is a fibrocartilaginous structure attached to the rim of the acetabulum. It extends the coverage of the femoral head, increases joint stability, and contributes to the sealing function of the hip joint.

Anatomy

The labrum is triangular in cross-section, attached to the acetabular rim. It is continuous with the transverse acetabular ligament inferiorly. Blood supply is from the capsular side (peripheral third), leaving the inner free margin relatively avascular — a key reason peripheral detachments repair more reliably than intrasubstance degeneration. The labrum contains free nerve endings and contributes to proprioception and nociception.

Function

The labrum creates a suction seal maintaining negative intra-articular pressure. It increases acetabular depth and surface area, contributing to load distribution and joint lubrication. Labral damage compromises this seal and alters joint mechanics.

Pathophysiology

Most labral tears are secondary, driven by underlying bony morphology:

• Cam FAI: an aspherical femoral head-neck junction (raised alpha angle) is forced into the acetabulum in flexion/internal rotation, shearing the labral-chondral junction from "outside-in" — producing the characteristic anterosuperior chondral delamination and labral detachment.
• Pincer FAI: focal or global acetabular over-coverage (e.g. retroversion, coxa profunda) causes the femoral neck to abut the rim, crushing the labrum and producing intrasubstance degeneration and rim ossification; a contre-coup posteroinferior chondral lesion may develop.
• Dysplasia/instability: acetabular under-coverage transfers load and shear onto the labrum, causing hypertrophy then tearing — a fundamentally different (instability) mechanism from impingement.
• Trauma/degeneration: dislocation, axial loading or twisting injuries, and age-related degeneration account for the remainder.

Once torn, loss of the suction seal increases cartilage consolidation and contact stress, establishing a degenerative cascade toward osteoarthritis.

History

Patients present with groin pain (most common), though may also describe anterior thigh, buttock, or lateral hip pain. Pain is typically activity-related and may be accompanied by mechanical symptoms (clicking, catching, locking). Prolonged sitting may aggravate symptoms. Athletes often report difficulty with sport-specific activities.

Examination

FADIR Test (Anterior Impingement Test): Flexion, Adduction, Internal Rotation reproduces groin pain. Most sensitive clinical test.

FABER Test: Flexion, Abduction, External Rotation may reproduce pain or indicate SI pathology.

Range of Motion: May be reduced, particularly internal rotation in flexion if FAI is present.

Gait: Usually normal unless significant pain or associated pathology.

Log Roll: May reproduce pain with minimal stress on the hip.

Complications of the Untreated Tear

• Progressive chondral damage and osteoarthritis — loss of the suction seal raises contact stress; persistent FAI drives the degenerative cascade.
• Chronic mechanical symptoms — catching, locking and instability limiting activity and sport.

Complications of Hip Arthroscopy

Groin and lateral hip pain in the young adult is a crowded field. The labral tear is frequently the visible lesion on imaging, but it is rarely the whole story — distinguishing the true pain generator (and the driving morphology) is the core clinical skill.

Global Epidemiology

• Labral tears are highly prevalent: cadaveric and asymptomatic-volunteer studies show labral abnormalities in the majority of older adult hips and in a large proportion of asymptomatic young athletes, so prevalence figures depend heavily on whether the population is symptomatic.
• The anterosuperior quadrant accounts for the substantial majority of tears across populations; posterior tears are uncommon and should prompt a search for dysplasia or prior trauma/dislocation.
• FAI-related labral pathology presents predominantly in active adults in the second-to-fourth decades; dysplasia-related pathology skews female and younger.

Side-by-Side Guideline / Consensus Positions

Registry & High-Volume Cohort Signals

• National and institutional hip-arthroscopy registries (e.g. UK Non-Arthroplasty Hip Registry and large North American databases) consistently report labral repair/preservation overtaking debridement as the dominant technique over the last decade, mirroring the comparative evidence.
• Predictors of conversion to total hip arthroplasty across registries are consistent: older age, pre-existing osteoarthritis/joint space narrowing, and advanced chondral damage — reinforcing careful patient selection.

High- vs Limited-Resource Practice Variation

• Well-resourced settings: MR arthrography and dedicated hip arthroscopy expertise are available; labral repair, capsular closure, and concurrent osteochondroplasty are standard, with PAO offered for dysplasia at specialist centres.
• Limited-resource settings: MR arthrography and arthroscopy may be scarce; diagnosis leans on plain radiographs, clinical tests and diagnostic injection, and management is often weighted toward optimised conservative care, with surgery reserved for, and referred to, specialist hip-preservation units.