The authors analyze thirty-five patients following arthroscopic and limited open femoral osteoplasty for symptomatic cam femoroacetabular impingement. Although the follow-up was short (less than three years), all patients were followed for at least two years after surgery. The fact that five additional patients were lost to follow-up prior to two years demonstrates the difficulty in locating young, mobile patients following nonprosthetic procedures. Given the importance of a complete data set, this study illustrates the potential benefits of a national registry that makes use of a unique HIPAA-protected patient identifier.
The authors enumerated their clinical and radiographic inclusion criteria. However, the clinical signs that they used, including restricted internal rotation, are not specific and are also not diagnostic of one particular pathologic condition. An "impingement sign" can also occur with iliopsoas bursitis, a tight or contracted anterior capsule, or a displaced labral tear, among other conditions. In addition, a morphologically abnormal femoral head is not by itself indicative of a pathologic condition. As the authors correctly point out, in the majority of patients the asymptomatic contralateral hip is similarly aspherical. Thus, it is imperative for the clinician to assimilate all of the clinical and radiographic imaging information before making a presumptive diagnosis of impingement. The final determinant, at times, needs to be made in the operating room, where direct arthroscopic visualization can occur during dynamic hip motion.
It is essential to arthroscopically assess and treat central compartment lesions prior to performing peripheral osteochondroplasty. In my personal experience, I have found that the treatment of anteromedial labral tears without the use of femoral osteoplasty can be associated with excellent clinical outcomes more than ten years after surgery. Conversely, anterolateral lesions of the labrum and/or acetabular cartilage usually require osseous resection to reduce the impingement.
The authors’ criteria for the treatment of femoral cam impingement are somewhat confusing. They express the importance of accurately assessing the extent and depth of chondral damage to the acetabulum and femoral head, which, if extensive, may preclude osteochondroplasty. And yet, in their cohort, more than 50% of the patients had Outerbridge Grade-IV full-thickness acetabular lesions and all of these patients underwent osteochondroplasty. This dichotomy points out the critical need for further improvements in imaging, not only of the labrum but also of the acetabulum and femoral head. Techniques such as delayed gadolinium-enhanced magnetic resonance imaging1 and possibly dynamic imaging would greatly assist clinicians to diagnose and treat patients at much earlier stages of disease. Our personal unpublished data clearly indicate improved outcomes more than ten years after surgery when chondral lesions are treated without accompanying chondral damage.