The concept of femoro-acetabular impingement is here to stay. There is already widespread recognition that dynamic "conflict" between the acetabular rim and the femoral head-neck area is a major cause of progressive arthrosis1.
Ganz and his colleagues have energized and revolutionized hip joint-preserving surgery by not only identifying the so-called cam and pincer subtypes of impingement as etiologic agents for arthrosis but also by developing the innovative and dramatic, yet safe, surgical dislocation approach to correct the impingement2.
The present study represents an important second generation of work from the Berne group in an attempt to improve their results in treating the pincer lesions. Although the association of certain proximal femoral deformities with cam impingement received most of the initial attention, recent studies3 suggest that relative rim overcoverage is a major pathogenetic factor in the majority of impinging hips.
It is not yet clear that preserving the acetabular labrum in the hip is as important as preserving the meniscus in the knee. The labrum, however, has several potential functions in the hip4,5, and Espinosa et al. have shown us that the labrum can be preserved by refixation even if an osteochondroplasty of the rim is carried out. After rim-trimming surgery, the labral refixation group recovered more quickly and had better pain relief than the labral resection group did.
The authors clearly state that their two treatment groups, although demographically similar, were sequential and not randomized, with the labral resection group preceding the labral refixation group. They concede that their increased surgical experience in group 2, the labral refixation group, could have positively influenced the results. In addition, some subtle selection bias could have occurred with time, through unnoted rejection of certain unfavorable patients for surgery as more experience was gained. Given these caveats, labral preservation seems desirable when possible.
An important factor that determines outcome in joint-preserving surgery is the amount of articular cartilage damage that has already occurred prior to the surgical intervention6,7. The average patient age in each of the treatment groups was thirty years. Most patients had been symptomatic for several years, and some degree of articular damage was present in each treated hip. Labral preservation and refixation seems to be a step forward in the treatment of pincer impingement. Even further incremental improvement can be anticipated with earlier diagnosis. The ideal treatment age for patients with femoro-acetabular impingement would seem to be soon after skeletal maturity, before articular damage has occurred.
While this preliminary study of the effect of labral refixation on the treatment of pincer impingement is interesting in itself, the greater significance of this work may be in the documentation of the continually improving results in treating femoro-acetabular impingement, from the group with the world's largest experience. Femoro-acetabular impingement is common, yet it still commonly remains undiagnosed. Even when femoro-acetabular impingement is diagnosed, many orthopaedists remain reluctant to undertake the surgical measures necessary to completely relieve the impingement.
Arthroscopic approaches are being used to relieve osseous impingement at both the femoral head-neck junction and at the acetabular rim, but reports with reasonable follow-up are not in print at this time. The gold standard for surgical relief of cam and pincer impingement remains the open approach originally described by Ganz et al. in 20012. In the last few years, a growing number of articles, including this report by Espinosa et al., have represented the evolution of increasingly effective diagnostic and therapeutic techniques. These techniques should be used in a timely fashion, and with regularity, to deal with this very treatable cause of osteoarthrosis of the hip.
*The author did not receive grants or outside funding in support of the research for or preparation of this manuscript. He did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author is affiliated or associated.
1. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res. 2003;417:112-20.
2. Ganz R, Gill TJ, Gautier E, Ganz K, Krugel N, Berlemann U. Surgical dislocation of the adult hip. A technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br. 2001;83:1119-24.
3. Beck M, Kalhor M, Leunig M, Ganz R. Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip. J Bone Joint Surg Br. 2005;87:1012-8.
4. Ferguson SJ, Bryant JT, Ganz R, Ito K. An in vitro investigation of the acetabular labral seal in joint mechanics. J Biomech. 2003;36:171-8.
5. Ferguson SJ, Bryant JT, Ganz R, Ito K. The influence of the acetabular labrum on hip joint cartilage consolidation: a poroelastic finite element model. J Biomech. 2000;33:953-60.
6. Beck M, Leunig M, Parvizi J, Boutier V, Wyss D, Ganz R. Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment. Clin Orthop Relat Res. 2004;418:67-73.
7. Murphy S, Tannast M, Kim YJ, Buly R, Millis MB. Debridement of the adult hip for femoroacetabular impingement: indications and preliminary clinical results. Clin Orthop Relat Res. 2004;429:178-81.