Abstract
Keywords
All that is human must retrograde if it does not advance.
Many years ago, I asked the late Howard Sweeny to see one of our Chicago varsity athletes who seemed to have an intra-articular hip problem. Together, the player and I made the pilgrimage from Chicago to Evanston where Dr. Sweeny, a pioneer of arthroscopic surgical techniques and education, positioned the patient on a conventional hip fracture table and conducted his masterful arthroscopic examination of the hip. At the time, indications for hip arthroscopy seemed few and far between. Dr. Sweeny was one of a handful of surgeons in the United States who were known for their expertise in the technique.
That was before Reinhold Ganz and his Bernese colleagues described femoroacetabular impingement (FAI) as a cause of what had hitherto been deemed idiopathic osteoarthritis of the hip. 7 The rest, as the saying goes, is history. Although Dr. Ganz treated the condition via open surgical dislocation of the hip, arthroscopic surgeons worldwide quickly recognized FAI as a prime candidate for arthroscopic treatment. Since then, the number of practitioners skilled in hip arthroscopy has grown rapidly, while the complexity and sophistication of the hip procedures that can be accomplished arthroscopically has evolved at a similar frenetic pace.
As an editor, I was quickly presented with a dilemma. Eager to be the first to publish their experience with a new technique, hip arthroscopists were submitting clinical studies with only 6 months of follow-up. I knew that these early series were likely to become landmark publications, but I also felt strongly that 6 months was much too short a time to appreciate the outcome of a novel surgical intervention. In fact, while 2 years is usually considered adequate to demonstrate the initial efficacy of a procedure, much longer follow-up is needed to assess the ultimate outcome, especially in the case of an intervention designed to delay or prevent the onset of osteoarthritis in a young patient. Two decades after Dr. Ganz's publication, hip arthroscopy studies with 10 or more years of follow-up are appearing with increasing frequency.2,3,5,9,15,16
In this month's
In a prior report on many of the same patients after 5 years of follow-up, 10 the authors classified 45% as having failed results: 20% who had further surgery on their operative hip, of whom 12% were total hip arthroplasties (THAs), and 25% who reported abnormal or severely abnormal function. In the current study, the authors were able to evaluate the status of 48 hips in 47 patients a mean of 17 years after surgery. At that point, 19 (40%) of the hips had received additional surgery, of which 16 (33%) were THAs, and an additional 5 (10%) were rated abnormal or severely abnormal for a total failure rate of 50%. Although the cohorts in the 2 studies may not have been identical, a comparison of the results suggests that most of the ultimate failures were evident at the 5-year mark, with the overall failure rate only demonstrating a modest 5% increase from 45% at 5 years to 50% at 17 years. The percentage with abnormal or severely abnormal function decreased from 25% to 10% during this interval, while the percentage receiving THAs increased from 12% to 33%, implying that many of the patients enduring abnormal function in the early postoperative years elected to seek improvement via a THA. Notably, the 50% of patients in the cases not deemed failures were not doing too badly: Their functional ratings on the modified Harris Hip Score (mHHS), Hip Outcome Score–Activities of Daily Living (HOS-ADL), and Hip Outcome Score–Sports Subscale (HOS-SS) were 82.2, 81.9, and 79.9, respectively. These scores were not significantly different from their 5-year ratings, suggesting that the outcomes in this lucky subset were fairly durable.
Differences between the patient selection guidelines and surgical protocols used in this study and current standards are evident. The authors included patients with radiographic Tönnis grade 2 arthritis in their cohort, while contemporary practice would usually consider this degree of degeneration to be a contraindication to arthroscopic treatment.
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Indeed, although they could not show that the Tönnis grade 2 patients did worse as a group, their univariate failure analysis demonstrated that patients who went on to have subsequent surgery had higher mean acetabular International Cartilage Regeneration & Joint Preservation Society chondral and acetabular labrum articular disruption grades at the time of surgery compared with patients who did not have subsequent surgery. They had not considered performing femoral or acetabular osteoplasty in any of their patients, pointing out that the landmark paper of Ganz and colleagues
7
describing FAI was not published until 2003, halfway through their collection period. Retrospective analysis, however, showed that 43% of the cohort had cam morphology, 8% had pincer morphology, and 38% had mixed cam and pincer morphology, suggesting that many of their patients would be candidates for osteoplasty if operated on today. Indeed, a 15-year follow-up study published last year in
In contrast with this study, another paper in this month's
Tönnis grade 1 radiographic changes are not generally considered an absolute contraindication to arthroscopic treatment of FAIS or labral tears, but are they associated with a worse ultimate prognosis? Another long-term study in this month's
At the 10-year follow-up, there were no significant differences between the Tönnis groups on any of the outcome measures. Although the differences were not statistically significant, the Tönnis grade 0 group did score consistently better on all measures; some of these differences were arguably clinically important in magnitude and may have proven statistically significant in a larger cohort. The rates of achieving MCID and PASS exhibited a similar pattern: no significant differences were identified, but the Tönnis grade 0 group consistently achieved these milestones at a higher rate, with some of the differences potentially clinically important. In the most extreme example, the mean iHOT-12 PASS rate was 71.2% for the Tönnis grade 0 group and 44.4% for the Tönnis grade 1 group. Additionally, although overall rates of secondary surgery were not significantly different, the rate of reoperation for the Tönnis grade 1 group was twice that of the Tönnis grade 0 group (29% vs 14.5%). Most of the reoperations in the Tönnis grade 1 group were conversions to THA, and the difference in THA conversion between the groups was both statistically and clinically significant, 25.8% compared with 4.8%.
Given these findings, it is not surprising that the authors state anecdotally that they have decreased their overall rate of primary hip arthroscopy on patients with Tönnis grade 1 osteoarthritis. As they note, the Tönnis classification is a radiographic one that can miss variations in articular degeneration that are readily visible during arthroscopy. Indeed, the Tönnis grade 1 patients had significantly worse femoral head and acetabular cartilage damage than the Tönnis grade 0 patients. Furthermore, within the Tönnis grade 1 group, the patients who went on to THA conversion had significantly worse femoral head damage than those who did not, even given the small numbers available for this subgroup analysis.
In view of the burgeoning importance of the treatment of hip disorders in orthopaedic sports medicine, Andrea Spiker joins the