Hip Labral Tears — Classification, Diagnosis & Arthroscopic Management

The acetabular labrum is a fibrocartilaginous rim attached to the bony margin of the acetabulum that deepens the hip socket, contributes to femoral head containment, and provides a fluid seal that maintains joint lubrication and intra-articular pressure. Labral tears are a significant source of hip pain in active adults and are strongly associated with femoroacetabular impingement (FAI) — the anterosuperior labrum is the most commonly torn segment, reflecting the anterosuperior location of cam impingement contact. Isolated labral tears without structural FAI are less common and may indicate hip dysplasia, trauma, or capsular laxity. With the advent of hip arthroscopy, labral tears are now routinely treated with repair rather than debridement, with markedly improved outcomes.

• Labral anatomy: the labrum is a triangular fibrocartilaginous structure encircling the acetabular rim continuously except at the inferior notch where the transverse acetabular ligament bridges the gap; it is attached to the bony acetabulum at its base (osseous attachment) and to the articular cartilage at the transition zone (the chondrolabral junction — the zone most vulnerable to tearing in FAI); the labrum deepens the acetabular socket from approximately 5 mm to 9 mm; the zone of chondrolabral junction is supplied by vascularity from the periacetabular vessels — the outer third of the labrum is vascular (capable of healing), while the inner two thirds are relatively avascular
• Function: (1) load distribution — distributes load across the acetabular cartilage, reducing peak contact stress; (2) fluid seal (suction seal) — the labrum creates a fluid film between the femoral head and the acetabular cartilage, maintaining intra-articular pressure that is essential for joint lubrication and femoral head containment; disruption of the seal dramatically increases contact stress and accelerates cartilage wear; (3) hip stability — provides approximately 22% of resistance to femoral head distraction forces

• Symptoms: anterior groin pain (C-sign); activity-related; sharp pain with sudden twisting or pivoting; a `clicking` or `catching` sensation within the hip (highly specific for labral tear); painful arc during hip flexion; pain with prolonged sitting; symptoms frequently overlap with FAI; isolated labral tears without FAI are less common and should prompt assessment for hip dysplasia (LCEA <20°) or hip instability (capsular laxity, EDS)
• FADIR test: as described in the FAI article — reproduces anterior groin pain; sensitivity ~88% for intra-articular pathology including labral tears; positive FADIR in the context of MRI-confirmed labral tear = high probability of symptomatic labral tear
• Scour test: the hip is flexed, adducted, and an axial compression force applied while rotating the hip through its arc; a positive test (reproduction of pain or clicking) suggests labral or chondral pathology; less specific than FADIR
• MR arthrography: the gold standard investigation for labral tears; intra-articular gadolinium distends the joint and enters the tear, making it visible on T1 fat-saturated sequences as a bright signal extending into the labrum; sensitivity ~90%, specificity ~91% for labral tears; superior to standard MRI (sensitivity ~65%); the anterosuperior labrum is best assessed on the coronal oblique sequence; radial sequences through the femoral head-neck junction simultaneously assess the cam deformity (alpha angle) and labral integrity; the preferred investigation before hip arthroscopy

• Labral repair (preferred over debridement): the torn labrum is reattached to the acetabular rim using suture anchors placed through arthroscopic portals (standard portals: anterolateral AL, mid-anterior MA, and proximal mid-anterior PMA — placed under fluoroscopic guidance); the labral base is prepared with a burr to create a bleeding bony bed; anchors are placed at the rim and sutures passed through the labral tissue to re-fix the detached labrum; typically 2–4 anchors per labral tear segment; the re-attached labrum must be watertight to restore the fluid seal; multiple studies (Larson, Philippon, Domb) demonstrate superior outcomes with labral repair vs debridement — labral debridement alone has worse pain scores, lower return-to-sport rates, and higher rates of conversion to THA at 5 years
• Labral debridement: reserved for labrums that are truly irreparable (frayed, macerated, degenerative tissue that cannot be sutured); debridement alone removes the painful torn tissue but does NOT restore the suction seal; associated with inferior outcomes compared to repair; avoid if any repairable tissue is present
• Labral reconstruction: for irreparable labral tears (previously debrided, severely degenerated, or insufficient tissue for repair); a graft is used to reconstruct the labrum; graft options: iliotibial band (most common), ligamentum teres, gracilis tendon, capsular tissue; the graft is secured at the acetabular rim using suture anchors in the same fashion as repair; restores the suction seal and containment function; indicated for revision hip arthroscopy after failed prior labral debridement
• Concurrent cam resection: labral repair without addressing the underlying cam deformity has a high failure rate; the cam lesion will continue to impinge against the repaired labrum and re-tear it; therefore labral repair must ALWAYS be combined with correction of the underlying structural cause (cam resection for cam FAI; rim trimming for focal pincer; PAO for hip dysplasia); failure to address the cause = predictable failure of the labral repair
• Post-operative rehabilitation: immediate partial weight-bearing with crutches for 2–4 weeks (to protect the suture anchors and allow labral healing); passive range of motion exercises from day 1 (hip pump exercises); no active hip flexion against resistance for 4–6 weeks (to protect the labral repair from the pull of the iliopsoas); progressive strengthening at 6–8 weeks; return to running at 3–4 months; return to sport at 4–6 months

• Outcomes of hip arthroscopy for labral tears associated with FAI: overall good/excellent outcomes in ~85% at 2 years; patient satisfaction ~80–90%; significant improvement in mHHS (modified Harris Hip Score), iHOT (International Hip Outcome Tool), and HOS (Hip Outcome Score); return-to-sport rates ~70–85% in athletes; outcomes are strongly correlated with the degree of pre-operative cartilage damage (Outerbridge grade and Tönnis grading); best outcomes in Tönnis 0–1 with minimal cartilage damage
• Labral repair vs debridement outcomes: in a landmark study by Larson et al. (2011), patients who underwent labral repair had significantly better 2-year outcomes than those who underwent debridement (mHHS 94 vs 88; return to sport 93% vs 77%); systematic reviews confirm this superiority; in revision hip arthroscopy for failed labral debridement, conversion to labral repair or reconstruction salvages approximately 70% of cases; the evidence overwhelmingly supports repair over debridement whenever tissue quality permits

• Labral anatomy: fibrocartilaginous rim deepening the acetabulum from 5 mm to 9 mm; continuous except at the inferior notch (transverse acetabular ligament bridges here); chondrolabral junction = most vulnerable zone in FAI; outer third vascular (can heal); inner two thirds avascular
• Seldes classification: Type 1 (detachment at chondrolabral junction — most common, amenable to repair); Type 2 (intralabral cleavage — may need debridement or reconstruction)
• MR arthrography: gold standard for labral tears; sensitivity ~90%; gadolinium enters the tear = bright signal on T1 fat-sat; standard MRI sensitivity only ~65%; always request MRA for suspected labral tear before arthroscopy planning
• Anterosuperior labrum = most common tear location (12-3 o`clock); associated with cam FAI; anterior labrum tears associated with hip dysplasia; always address the structural cause (cam resection) at the time of labral repair — failure to do so = predictable failure of repair
• Repair > debridement: labral repair restores the suction seal and provides significantly better long-term outcomes; debridement alone — pain relief initially but poor long-term (loss of suction seal accelerates cartilage wear); labral reconstruction for irreparable tears (ITB graft most common)
• Post-op protocol: crutches 2–4 weeks; no active hip flexion resistance 4–6 weeks; return to sport 4–6 months; return to high-level sport dependent on chondral status