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What fooled us in the knee may trip us up in the hip: lessons from arthroscopy
  1. Joanne L Kemp1,
  2. Kay M Crossley2,
  3. Ewa M Roos3,
  4. Charles Ratzlaff4
  1. 1Australian Centre for Research into Injury in Sport and its Prevention (ACRISP), Federation University Australia, Ballarat, Victoria, Australia
  2. 2School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Queensland, Australia
  3. 3Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
  4. 4Department of Bone Radiology and Rheumatology, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, USA
  1. Correspondence to Joanne L Kemp, Australian Centre for Research into Injury in Sport and its Prevention (ACRISP), Federation University Australia, P.O. Box 663, Ballarat, VIC 3350, Australia; jkemp{at}

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“The only good thing about repeating your mistakes is you know when to cringe.” Aleksandr Solzhenitsyn

Those old enough to remember when knee arthroscopy revolutionised treatment of the injured meniscus several decades back might be forgiven if a sense of déjà vu is emerging from the hip. Hip labral tears are increasingly seen on imaging and at hip arthroscopy in people with hip and groin pain, which coincides with improved diagnostic techniques and the rapid growth of arthroscopic surgery.1 The number of hip arthroscopies have increased 1800% in the USA over the past 5–10 years,2 with dramatic increases also reported in the UK, Australia and elsewhere worldwide.

The similarities between the meniscus and labrum are striking on several fronts. The knee meniscus and acetabular labrum are comprised of fibrocartilage that has a partially innervated peripheral vascular red zone.3 They are critical to maintain optimal joint force distribution and attenuation and to ensure lubrication and nutrition of articular cartilage via synovial fluid pressure, hence they maintain healthy chondral surfaces.4 ,5 Not surprisingly, their disruption appears to be a potent risk factor for, or an early sign of, osteoarthritis (OA).6 Considering the similarities in structure and function, perhaps similar treatment strategies of both structures should prevail.

There is no randomised controlled trial evidence supporting arthroscopic meniscectomy

Thirty years ago knee arthroscopy revolutionised the surgical approach to the knee and meniscectomy became the treatment of choice for meniscal tears. However, long-term follow-up studies showed poor patient-reported pain and functional outcomes and a 14-fold increase in OA at 20 years compared with controls.7 Even more compelling, five high-quality randomised control trials recently reported that the pain relief and functional improvements observed with arthroscopic meniscectomy, in knees with or without concomitant OA, were no greater than from placebo surgery or non-surgical treatments8 ( As a result, arthroscopic meniscal debridement and meniscectomy for degenerative tears and OA is no longer generally recommended6 (

Will randomised controlled trial evidence for hip arthroscopy be similar to knee meniscectomy?

Current practice for acetabular labral tears is arthroscopic labral resection, debridement or repair. This practice is supported by a growing body of level IV evidence, as highlighted in our recent systematic review.1 Early surgical outcomes in the hip appear to mirror what we know about the knee: repair and preservation is better than debridement, which is better than resection. While these case series report improvements in pain and function for up to 10 years postoperatively the long-term effect of labral repair are unknown. Critically, the lack of randomised controlled trials limits confidence in these results.1

Can we learn from the meniscus? Improvements seen in patient-reported outcomes in uncontrolled trials of labral surgery reflect those observed in meniscal surgery, which were later refuted by high-quality randomised controlled trials8 ( Furthermore, there are rich epidemiological data describing OA development following arthroscopic meniscal surgery at the knee.6 Is it possible that arthroscopic labral surgery does not result in superior outcomes compared with non-surgical interventions or reduce the risk of hip OA?

Importantly, and similar to the arthroscopic meniscal procedure, patients with labral pathology and coexisting chondral lesions report poor patient-reported outcomes1 ,9 in line with those reported in advanced OA. Moreover, similar to the knee, concomitant labral and chondral pathology may result in end-stage hip OA and subsequent total hip arthroplasty.9

Studies into non-surgical management of labral tears are rare.1 There are no randomised controlled trials comparing surgical and non-surgical management of labral tears.1 Similar to the knee, non-surgical treatment strategies for labral tears may restore optimal joint mechanics and reduce load on the damaged labrum. These may include hip muscle strengthening, manual therapy techniques to improve joint range of motion and reduce impingement, movement retraining, neuromuscular programmes that improve gait biomechanics, and weight control. Such strategies may have similar or better effects on patient-reported outcomes and progression to hip OA than surgical strategies.

Randomised controlled trials investigating surgical and non-surgical treatments are urgently needed if the failures of the management of meniscal injuries are to be avoided in patients with acetabular labral pathology, and an epidemic of postsurgical hip OA is to be avoided.


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  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.