When present, delaminated acetabular cartilage was débrided to a stable edge. Since this report represents the initial experience of the senior author, only two hips had surgical detachment of the labrum to remove a prominent acetabular rim and/or remove exposed subchondral bone secondary to a delaminated segment. In these two hips, the labrum was reattached with two or three suture anchors25.
Postoperatively, all patients used crutches for six weeks with partial weight-bearing, after which physical therapy was initiated and performed for a period of six to eight weeks. Physical therapy consisted of stretching and range-of-motion exercises as well as a muscle-strengthening program.
The difference between the preoperative and follow-up hip scores was analyzed with paired Student t tests. Significance was determined to be p < 0.05.
Of the thirty-seven hips that underwent surgery, two were categorized as type 3 according to the criteria described by Beck et al.11; twenty, as type 4; and six, as type 5 (Table I). The remaining nine hips had normal-appearing cartilage.
At a mean of 3.1 years (range, 2.1 to 5.0 years) postoperatively, none of the patients has undergone additional reconstructive hip surgery. Six patients (three women and three men) had an unsatisfactory outcome with no clinical improvement and/or worsening of the WOMAC score. The mean postoperative outcome scores in the whole group of patients significantly improved compared with the preoperative scores. The mean WOMAC score (and standard deviation) improved from 61.2 ± 20 to 81.4 ± 16 points (p < 0.001). The mean UCLA activity score improved from 4.8 ± 1.9 to 7.5 ± 2.4 points (p < 0.001) (Fig. 2). The mean SF-12 physical and mental component scores improved from 37.3 ± 10.4 to 45.6 ± 10.5 points (p < 0.001) and from 46.4 ± 11.4 to 51.2 ± 11.3 points (p = 0.031), respectively. Eleven of the thirty-four patients underwent surgical interventions on the contralateral hip.
One patient had failure of the trochanteric fixation at three weeks postoperatively; this required refixation, which was followed by uneventful healing. One patient had Brooker26 Grade-IV heterotopic ossification, which required excision at ten months postoperatively. At the time of the latest follow-up, twenty-six months postoperatively, he had returned to full participation in activities with no pain. In nine hips, painful internal fixation devices in the greater trochanter created persistent bursitis, which necessitated removal of the screws at a mean of eight months (range, six to fourteen months) postoperatively. All patients became asymptomatic and returned to full activities after the screws were removed.
This study demonstrated that femoral head-neck offset for the treatment of cam-type femoroacetabular impingement results in early improvement in both disease-specific and health-related outcomes and confirmed the previous findings of Beck et al.11 and Murphy et al.12. Notably, the majority of previous authors25,27-29 who evaluated nonarthritic hip pain and its treatment used outcome tools such as the Merle d'Aubigné30 or Harris hip score31, which were developed for the assessment of the results of total hip arthroplasty. Although these hip scores adequately describe a patient's physical ability after total hip arthroplasty, they do not necessarily provide a full assessment of the patient's quality of life as general health-related quality-of-life measures do32-34. To our knowledge, the only other study in which global and disease-specific health-related quality-of-life measures were used to evaluate patients with nonarthritic hip pain was that by van Bergayk and Garbuz35, who assessed patients with hip dysplasia. As was the case in our study, they noted that patients were substantially incapacitated with regard to their ability to perform activities of daily living despite having no signs of advanced hip arthritis. By using the UCLA activity scale, we also documented the active use of the hips by these patients36,37. This is especially relevant since the capacity of these younger patients to participate in sports activities improved significantly, with 56% having a UCLA activity score of ≥8 points.
Although labral tears per se were the initial focus of interest in the treatment of prearthritic hip pain38-40, there is a growing body of evidence that, in many patients, structural osseous abnormalities are the cause of the labral tears41,42 and that acetabular cartilage damage is also present6,8,11,38,43,44. McCarthy et al.43 noted damage to the acetabular cartilage adjacent to a labral tear in 62.8% (273) of 435 hips and described it as an erosion and/or a flap. In a more recent report on the treatment of femoroacetabular impingement, Beck et al.11 noted that eighteen of nineteen hips with pathological changes in the labrum had associated damage to the acetabular cartilage. In our study, damage to the acetabular cartilage was found in twenty-seven of thirty-seven hips, including six of the seven patients with an unsatisfactory outcome. Although damage to the acetabular cartilage represents an advanced disease state, it cannot fully account for the poor outcomes in our series, since nineteen patients (twenty hips) with a good outcome also had some degree of damage to the acetabular cartilage. Thus, other factors such as unrecognized acetabular retroversion may have played a role. Our current inability to properly assess the overall health of articular cartilage requires better imaging techniques such as magnetic resonance imaging with gadolinium arthrography45,46 or delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC)47 to detect cartilage lesions earlier in the disease process and enable physicians to provide more adequate counsel to patients with respect to the longevity of their hip joint.
Another unresolved issue in the management of femoroacetabular impingement is how to treat the associated delamination of the acetabular cartilage in the presence of pathological changes in the labrum. Currently, there are no specific guidelines in terms of how much of the acetabular floor can be left exposed once the delaminated segment has been removed or whether labral refixation after removal of exposed subchondral bone substantially improves the ultimate outcome. Recently, Espinosa et al.25 reported that the results of procedures in which as much of the intact labrum as possible had been preserved were superior to those of labral resection. In our series, none of the patients who had a poor outcome had had labral refixation. However, despite these limitations in our treatment, 82% (twenty-eight) of our thirty-four patients had improvement after osseous correction and partial labral débridement although there is a general consensus that preservation of a healthy labrum is beneficial to hip function25,43,48,49. Additional research is needed to better define the natural history of this osseous dysmorphism as well as to determine whether correction of this deformity alters the natural history of femoroacetabular impingement4,50.
Although our early clinical results are very encouraging, ten patients required a reoperation that was directly related to the surgical dislocation approach (e.g., screw removal or a reoperation because of failed trochanteric fixation). Consequently, we hope that in the future this condition can be treated with less-invasive techniques, such as hip arthroscopy51 or limited anterior hip arthrotomy52. Also, with improved imaging techniques to assess the health of articular cartilage, earlier diagnosis should allow more timely surgical intervention prior to the development of irreversible chondral degeneration. ▪
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