Access to the hip joint by arthroscopic

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1 n Review Article Instructions 1. Review the stated learning objectives at the beginning of the CME article and determine if these objectives match your individual learning needs. 2. Read the article carefully. Do not neglect the tables and other illustrative materials, as they have been selected to enhance your knowledge and understanding. 3. The following quiz questions have been designed to provide a useful link between the CME article in the issue and your everyday practice. Read each question, choose the correct answer, and record your answer on the CME Registration Form at the end of the quiz. 4. Type or print your full name and address and your date of birth in the space provided on the CME Registration Form. 5. Indicate the total time spent on the activity (reading article and completing quiz). Forms and quizzes cannot be processed if this section is incomplete. All participants are required by the accreditation agency to attest to the time spent completing the activity. 6. Complete the Evaluation portion of the CME Regi stration Form. Forms and quizzes cannot be processed if the Evaluation portion is incomplete. The Evaluation portion of the CME Registration Form will be separated from the quiz upon receipt at Orthopedics. Your evaluation of this activity will in no way affect the scoring of your quiz. 7. Send the completed form, with your $15 payment (check or money order in US dollars drawn on a US bank, or credit card information) to: Orthopedics CME Quiz, PO Box 36, Thorofare, NJ 08086, OR take the quiz online. Visit www. Healio.com/EducationLab/Orthopedics for details. 8. Your answers will be graded, and you will be advised whether you have passed or failed. Unanswered questions will be considered incorrect. A score of at least 80% is required to pass. If a passing score is achieved, Vindico Medical Education will issue an AMA PRA Category 1 certificate within 4-6 weeks. 9. Be sure to mail the CME Registration Form on or before the deadline listed. After that date, the quiz will close. CME Registration Forms received after the date listed will not be processed. CME ACCREDITATION This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Vindico Medical Education and Orthopedics. Vindico Medical Education is accredited by the ACCME to provide continuing medical education for physicians. Vindico Medical Education designates this Journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit. Physicians should claim only the credit commensurate with the extent of their participation in the activity. This CME activity is primarily targeted to orthopedic surgeons, hand surgeons, head and neck surgeons, trauma surgeons, physical medicine specialists, and rheumatologists. There is no specific background requirement for participants taking this activity. FULL DISCLOSURE POLICY In accordance with the Accreditation Council for Continuing Medical Education s Standards for Commercial Support, all CME providers are required to disclose to the activity audience the relevant financial relationships of the planners, teachers, and authors involved in the development of CME content. An individual has a relevant financial relationship if he or she has a financial relationship in any amount occurring in the last 12 months with a commercial interest whose products or services are discussed in the CME activity content over which the individual has control. Drs Ward and Youm and Mr Rogers have no relevant financial relationships to disclose. Dr Aboulafia, CME Editor, has no relevant financial relationships to disclose. Dr D Ambrosia, Editor-in-Chief, has no relevant financial relationships to disclose. The staff of Orthopedics have no relevant financial relationships to disclose. UNLABELED AND INVESTIGATIONAL USAGE The audience is advised that this continuing medical education activity may contain references to unlabeled uses of FDA-approved products or to products not approved by the FDA for use in the United States. The faculty members have been made aware of their obligation to disclose such usage. Failed Hip Arthroscopy: Causes and Treatment Options James P. Ward, MD; Patrick Rogers, BS; Thomas Youm, MD educational objectives As a result of reading this article, physicians should be able to: 1. Identify the underlying factors and diagnoses associated with unsatisfactory postoperative outcomes after hip arthroscopy. 2. Outline the necessary steps for preoperative identification of developmental dysplasia of the hip and assess how it can affect the outcome of arthroscopy for labral pathology. 3. Identify the association of unrecognized femoroacetabular impingement lesions with suboptimal outcomes. 4. Identify whether labral debridement or labral repair is associated with improved postoperative outcomes. Abstract Indications for arthroscopic surgery of the hip have increased over the past several years, along with the number of procedures performed annually. In addition, the number of unsuccessful procedures and subsequent revision surgeries have also increased. Recent literature has defined several common causes for failed hip arthroscopy. Severe osteoarthritis and osteonecrosis are associated with poor outcomes. Findings during revision hip arthroscopy consistently demonstrate untreated femoroacetabular impingement, chondral defects, labral tears, and postoperative adhesions. The treating surgeon must be diligent in his or her indications for surgery, as well as in addressing all pathology at the initial surgery. Drs Ward and Youm are from the Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, and Mr Rogers is from New York Institute of Technology, New York, New York. The material presented in any Vindico Medical Education continuing education activity does not necessarily reflect the views and opinions of Orthopedics or Vindico Medical Education. Neither Orthopedics nor Vindico Medical Education nor the authors endorse or recommend any techniques, commercial products, or manufacturers. The authors may discuss the use of materials and/or products that have not yet been approved by the US Food and Drug Administration. All readers and continuing education participants should verify all information before treating patients or using any product. Correspondence should be addressed to: James P. Ward, MD, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 E 17th St, Ste 1402, New York, NY (jamespward@gmail.com). doi: / ORTHOPEDICS Healio.com/Orthopedics

2 Failed Hip Arthroscopy Ward et al Access to the hip joint by arthroscopic means was once considered an impossible task due to the complexity of the joint and the inability to insert an instrument directly between the femoral head and acetabulum. 1 Since Burman s 1 initial report, advances in surgical techniques have not only proven arthroscopy to be a safe and effective tool in treating hip pathology, but have also allowed for the diagnosis of previously unrecognized, and thus untreated, hip conditions. 2 It is important to recognize that such strides have created new options for patients and surgeons and have provided a greater understanding of the nature of the intra-articular hip pathology. Indications for hip arthroscopy have expanded significantly and currently include symptomatic acetabular labral tears, hip capsule laxity and instability, chondral lesions, osteochondritis dissecans, ligamentum teres injuries, snapping hip syndrome, iliospsoas bursitis, loose bodies, and femoroacetabular impingement. Less commonly used indications include management of the early stages of osteonecrosis of the femoral head, synovial abnormalities, crystalline hip arthropathy, infection, and posttraumatic intra-articular debris. 3 Under judicial discretion of the treating surgeon, hip arthroscopy has been useful in treating symptoms and delaying the need for total hip arthroplasty (THA) in some cases of mild to moderate osteoarthritis. 4,5 This expanding list of indications and operative techniques has led to a subsequent increase in hip arthroscopy procedures performed annually. Consequently, this has also led to an increase in failed arthroscopy and revision procedures. Presence of Osteoarthritis Although hip arthroscopy has become a reliable option in treating many pathologic hip conditions, the treating physician must be diligent in assessing the overall condition of the joint, as well as in making an accurate preoperative diagnosis. Failed hip arthroscopy, defined as either persistent pain or eventual total hip replacement, has been attributed to incorrect preoperative diagnosis and poor patient selection. 4,6 In determining whether hip arthroscopy is an option for the treatment of a particular condition, the treating physician should pay considerable attention to the presence and the degree of degenerative change within the hip joint. Current evidence demonstrates limited success and suboptimal outcomes after arthroscopic intervention indicated for symptomatic relief of early stages of osteoarthritis. 4,5 Furthermore, the presence of arthritis in conjunction with any other indication for arthroscopic intervention has been shown to be an indicator of poor postoperative results. 7-9 Beck et al 9 evaluated the outcomes of arthroscopy in 19 patients with femoroacetabular impingement, noting that 5 patients underwent a THA at an average of 3.1 years postoperatively. Of these 5 patients, 2 had a preoperative diagnosis of grade II osteoarthritis (defined as thinned cartilage and possible full-thickness defects and fissuring to subchondral bone), 2 had severe acetabular cartilage damage in combination with a large defect in the femoral head, and 1 had an untreated ossified labrum. These findings were apparent preoperatively, and the authors concluded that these failures were due to poor patient selection. They cited the importance of preoperative diagnosis and scrutiny of the plain radiographs for signs of osteoarthritis. 9 Further studies affirmed the findings of Beck et al. 9 Murphy et al 10 reviewed 23 cases of arthroscopic debridement for femoroacetabular impingement and reported that 7 of these patients went on to undergo a THA. One patient had circumferential osteophyte formation causing extrusion of the femoral head, and 2 had residual untreated acetabular dysplasia. The remaining 4 patients underwent conversion to THA between 6.4 and 9.5 years postoperatively, enjoying improvement in symptomatology and function in the intervening time period. 10 Horisberger et al 8 determined that 10 of 20 patients undergoing arthroscopy for femoroacetabular impingement who presented with preoperative osteoarthritis in addition to chondral damage underwent a subsequent THA. Of these patients, 3 were diagnosed preoperatively with Tonnis grade 1 osteoarthritis, 2 with grade 2, and 5 with grade 3 (defined as debonding of cartilage from subchondral bone). In a retrospective review, Kim et al 11 also reported that arthroscopic intervention for early-stage osteoarthritis in the presence of femoroacetabular impingement is associated with poor clinical results because of a failure to alleviate symptoms associated with osteoarthritis. Philippon et al 7 evaluated the role of microfracture for the treatment of chondral lesions. They performed second-look arthroscopy on 9 patients and reported 95% to 100% fill of the lesions in 8 patients. The repair product appeared normal and was difficult to discern from the surrounding cartilage or demonstrated mild fibrillations and softening or discoloration. The sole failure was noted to be in a patient with diffuse osteoarthritis. The authors concluded that a microfracture technique may be applicable to chondral lesions of the hip, similar to the level of success that has been demonstrated in knee arthroscopy. 7 Presence of Osteonecrosis In addition to preoperative radiographs noting the presence of osteoarthritis, it is also important to diagnose osteonecrosis of the femoral head. 12 Patients with persistent pain and mechanical symptoms associated with end-stage osteonecrosis are not suitable candidates to undergo hip arthroscopy because outcomes studies demonstrate little success in alleviating symptoms and delaying the need for THA. 6,13 O Leary et al 6 retrospectively reviewed 86 arthroscopy procedures, of which 37 (43%) were indicated for osteonecrosis before or after JULY 2012 Volume 35 Number 7 613

3 n Review Article free vascularized fibular graft. Thirty-four of 37 patients were found preoperatively to have Ficat stage III or IV involvement of the hip and were indicated for debridement of the unstable cartilage lesions and associated mechanical symptoms. Overall results were poor, with only 35% reporting significant relief of symptoms postoperatively. Forty percent of patients underwent conversion to THA at an average of 8 months postarthroscopy. However, patients with mechanical symptoms seemed to fare better after arthroscopy that patients with pain alone. 6 Byrd and Jones 13 prospectively evaluated 52 hips with a 10-year follow-up and reported that 27% were converted to THA. Of the 14 patients with osteoarthritis, 11 were converted to THA, and 75% of patients diagnosed preoperatively with osteonecrosis underwent THA during the study period. The authors noted that the results of these patients were uniformly poor. 13 These findings highlight the importance of patient selection and preoperative diagnosis with regard to osteoarthritis and osteonecrosis in predicting success of arthroscopic treatment of hip discomfort and tempering patient expectations. Failed Hip Arthroscopy and Revision Findings Because hip arthroscopy is an emerging surgical technique, literature regarding failed hip arthroscopy and related causes is sparse. Several causes have been linked to unsuccessful hip arthroscopy and persistent impingement, which include unaddressed bony abnormalities and dysplasia, unaddressed or inadequately addressed femoroacetabular impingement, chondral defects, postsurgical adhesions, unaddressed instability, iatrogenic causes, and the decision between labral debridement vs labral repair. Bony Abnormalities and Hip Dysplasia Developmental dysplasia of the hip (DDH) is a condition associated with morphologic bony abnormalities that often results in intra-articular lesions and can be the source of significant mechanical hip pain. 14,15 Such abnormalities can be associated with hypertrophy of the labrum to increase the weight-bearing surface area in an attempt to compensate for a lack of joint stability and coverage of the femoral head. Such compensation exposes the labrum to abnormal mechanical forces and predisposes it to tearing. 14 Symptomatic labral tears associated with pathologies such as femoroacetabular impingement are a usual indication for arthroscopic treatment; however, addressing similar pathology associated with DDH with arthroscopic debridement or repair proves to be a more complex matter. 16 Patients with labral tears due to underlying DDH may expect to have little to no symptomatic benefit from the procedure. 14,17-19 Acetabular labral tears treated symptomatically without recognizing or addressing the underlying etiology of DDH is a likely cause of failure of arthroscopic means. 18 Failure rates may also be attributed not only to the fact that DDH is the fundamental cause of symptomatic tears, but also to the complexity of intra-articular pathology caused by the presence of radiographic evidence of dysplasia. Byrd and Jones 14 retrospectively reviewed 48 patients with dysplasia who underwent hip arthroscopy for various indications. Dysplasia was defined as a center-edge angle less than 25º. All patients were noted to significantly improve with regard to pre- and postoperative modified Harris Hip Scores, with 79% experiencing an improvement greater than 10 points. The authors proposed that DDH is not an absolute contraindication to hip arthroscopy. 14 Conversely, Parvizi et al 18 proposed that arthroscopic labral excision alone in these cases is not only indicative of poor clinical results, but it may also cause more harm to the patient. It has been hypothesized that excision alone in the presence of DDH may further compromise the biomechanics of the hip and increase stress on the lateral region of the acetabulum. In addition, patients with DDH are also likely to have chondral lesions that are contributing to their symptoms. Arthroscopic debridement of these lesions without addressing the morphological condition that led to such symptoms is likely to compromise and exacerbate deterioration of the remaining labrum and articular cartilage, accelerating the onset of osteoarthritis in some cases. 18 In patients presenting with hip pain due to symptomatic dysplasia, it is imperative to identify this pathology from radiographs and a thorough history and physical examination due to the aforementioned shortcomings in only treating the resulting labral tears. For individuals with DDH, the underlying pathology should be addressed and is done so through procedures such as a Ganz periacetabluar osteotomy. 20 Femoroacetabular Impingement Femoroacetabular impingement is the result of abnormal contact between the head of the femur and the acetabulum leading to hip pain, chondral pathology, and eventual osteoarthritis. Femoroacetabular impingement has 2 distinct mechanisms: cam and pincer impingement. Cam impingement results from an abnormal femoral head neck junction contact with the acetabulum. Such impingement leads to shearing stress on the acetabulum resulting in acetabular chondral delamination and labral detachment and degeneration. Pincer impingement is the result of a deep acetabulum and local anterior or posterior overcoverage, leading to crushing of the labrum between the abnormal acetabulum and femoral neck. 9,21 In general, arthroscopic treatment of femoroacetabular impingement has been successful, but in the published research regarding revision hip arthroscopy, the leading indication is persistent symptomatic impingement. 19 Although femoroacetabular impingement has 2 distinct mechanisms, it is not uncommon for an individual to have pain resulting from a 614 ORTHOPEDICS Healio.com/Orthopedics

4 Failed Hip Arthroscopy Ward et al combined cam pincer lesion. 22 A failure to recognize or inadequately address such combined lesions may result in persistent pain and a subsequent revision procedure. Heyworth et al 17 retrospectively reviewed 24 cases of revision hip arthroscopy and reported that 54% of cases had no improvement after the index procedure. The most common reason for revision arthroscopy was unaddressed or untreated bony impingement lesions, which were found in 79% of cases. Furthermore, 25% of the patients underwent treatment of either a cam or pincer lesion at the time of index surgery, only to have the corresponding lesion treated at the revision surgery. 17 Philippon et al 19 reviewed 37 procedures and reported that 95% of revision cases were performed for unaddressed femoroacetabular impingement. Untreated labral lesions and chondral pathology were also common in conjunction with the femoroacetabular impingement. All but 1 case had prerevision radiographic findings indicative of femoroacetabular impingement. 19 Chondral Defects Perhaps one of the most predictive preoperative prognostic factors in the success of hip arthroscopy is the degree of chondral damage within the hip joint prior to the procedure. In patients seeking revision hip arthroscopy for unresolved impingement, these symptoms were due to persistent cartilage damage in 70% of cases. 19 The degree of chondral damage has been determined to be an independent predictor of arthroscopic failure, even when considering hip arthroscopy for current indications, such as femoroacetabular impingement. 4,23,24 Specifically, a preoperative diagnosis of Outerbridge grade 2 or higher cartilage lesions will significantly reduce the effectiveness of arthroscopic treatment Failure to recognize advanced cartilage damage within the acetabulum is an independent negative prognostic factor for successful hip arthroscopy. Londers and Van Melkebeek 26 evaluated the success of hip arthroscopy with long-term follow-up in patients with no preoperative radiographic evidence of osteoarthritis or bony abnormalities. Of the 56 cases studied, 33 patients presented with Outerbridge grade 1 or 2 cartilage lesions in addition to pathology such as labral tears, loose bodies, or synovial hypertrophy. All 33 patients reported positive results at short-term follow-up, and 30 continued to report alleviation of symptoms at 5- to 10- year follow-up. However, 10 patients initially presented with Outerbridge grade 3 or 4 cartilage lesions in addition to labral tears or loose bodies. At 3-month followup, all 10 patients reported no change or worsening of their symptoms. At the final evaluation between 5 and 10 years postoperatively, 7 of these patients underwent conversion to THA. The role of cartilage lesions in femoroacetabular impingement treatment and outcomes has been demonstrated to have limiting effects. Javed and O Donnell 23 evaluated 40 patients older than 60 years undergoing arthroscopic intervention for femoroacetabular impingement. Seven of these patients presented with Outerbridge grade 3 cartilage lesions, and all 7 patients had a THA within an average of 12 months postarthroscopy. The role of articular cartilage lesions in debridement of labral lesions, as well as the significance in the difference in Outerbridge grading, was demonstrated by Streich et al. 25 They reviewed 50 cases indicated for hip arthroscopy for the treatment of labral tears without evidence of femoroacetabular impingement or dysplasia. Thirty of the patients presented with lesions less than Outerbridge grade 2, whereas 20 presented with lesions greater than or equal to grade 2. Postoperatively, the group with lesions less than grade 2 showed no degenerative alterations and showed clinical improvement, whereas all 20 patients with lesions greater than or equal to grade 2 remained at the same level of clinical symptomology or worsened. Such findings yielded a conclusion that cartilage lesions are a limiting factor in outcomes of hip arthroscopy when present. 25 McCarthy et al 24 reported that highgrade acetabular or femoral chondral lesions were associated with 22% and 12% 10-year hip arthroscopy survivorship, respectively. Furthermore, they determined that the presence of Outerbridge grade 3 or 4 cartilage lesions correlates with a 20- to 58-times increase in the likelihood of failed arthroscopy and the need for conversion to THA. 24 With such statistics, it is imperative to note the importance of patient selection and diligence in preoperative diagnosis. Radiographs and magnetic resonance imaging tend to underestimate the degree of chondral lesions and osteoarthritis. 8 Magnetic resonance arthrography may provide better visualization of chondral defects than plain magnetic resonance imaging, although this modality is still somewhat limited. Further improvements in magnetic resonance resolution and imaging are necessary for better visualization of such defects to help identify patients who will benefit from arthroscopic procedures. 4 Labral Debridement Vs Repair The intrinsic nature of the acetabular labrum is to function in shock absorption, joint lubrication, and pressure distribution. 27,28 This is especially significant in a major load-bearing joint such as the hip. Therefore, it is generally assumed that preservation and repair to keep the labrum intact is preferred to labral debridement or excision Espinosa et al 29 retrospectively reviewed 60 cases of arthroscopy for femoroacetabular impingement. The patients were divided consecutively into 2 groups, with the first 25 patients undergoing labral debridement and the next 35 undergoing refixation. The groups were evaluated with Tonnis arthrosis scores and Merle d Aubigne scores. At 2-year follow-up, JULY 2012 Volume 35 Number 7 615

5 n Review Article 76% of patients in the resection group and 94% in the refixation group reported good or excellent results. Clinical scores were significantly better in the refixation group at both 1- and 2-year follow-up. 29 Larson and Giveans 31 reviewed 2 groups undergoing arthroscopy for pincer or combined pincer cam lesions. One group was treated with labral debridement and the other with labral refixation with 1-year follow-up using the modified Harris Hip Score as a primary outcome measure. The postoperative modified Harris Hip Score for the group undergoing labral refixation was an average of 5 points greater than that of the group undergoing labral debridement. It was also noted that patients who underwent labral refixation subjectively reported good or excellent outcomes in 90% of cases, compared with 67% of labral debridment cases. With respect to the incidence of unsuccessful arthroscopic procedures, this number was also found to be greater in the debridement group. 31 Postoperative Adhesions Recent literature has identified other possible mechanisms of failure on evaluation of revision procedures. 17,19 In addition to aforementioned causes of failure, Philippon et al 19 identified postsurgical adhesions as a common cause for revision hip arthroscopy. In a review of 37 cases, they reported that adhesions were the primary cause of failure in 22 (59%) cases. Such adhesions were typically found at the site of previous labral repair and the capsule, in the area of greatest labral vascularity. It has been suggested that increased emphasis on early postoperative ROM may decrease to incidence of adhesions. A secondary cause of failure in this cohort was unaddressed instability, which was noted in 13% of the original arthroscopic procedures. 19 Intraoperative Complications The overall intraoperative complication rate associated with hip arthroscopy has been reported to be between 0.5% and 6.4% The majority of these cases are due to transient neuropraxia of the pudendal, sciatic, or peroneal nerves as a result of excessive distraction of the joint and prolonged traction during surgery. 32,34,35 Such neuropraxias may be preventable with implementation of a distraction force of less than 50 pounds for less than 2 hours, with a perineal post 7 to 9 cm in diameter. 34 The majority of these neurological complications refrain from being long-term factors contributing to failure of the arthroscopic procedure. However, rarely have major complications been reported with an incidence rate under 1% to contribute to an unsuccessful surgery. 34 Major complications included septic arthritis, osteonecrosis of the femoral head due to prolonged traction, and iatrogenic chondral scuffing. 34,37 It has been postulated that iatrogenic chondral scuffing and intraoperative trauma from instrumentation are the most common sources of significant complication associated with hip arthroscopy, yet they are underreported. 38 This makes it difficult to assess their role in failed hip arthroscopy and their contribution to the need for revision surgery. A serious concern that may lead to an unanticipated abrupt end to the procedure and potentially devastating sequelae is the threat of fluid extravasation leading to abdominal compartment syndrome. This is of greatest concern with longer operative times and extra-articular procedures, such as iliopsoas tendon release. 34,39,40 These circumstances may permit irrigation fluid to leak into the extra-articular tissue, travel along the iliopsoas tendon and muscle, and collect in retroperitoneal and intraperitoneal cavities of the abdomen. 39 Although rare, the operating surgeon must be aware of this potentially life-threatening complication. Conclusion The ability to perform arthroscopic hip surgery has provided orthopedic surgeons with a new tool to diagnose and treat a wide variety of pathologic conditions of the hip. As the number of procedures performed increases annually, so does the number of failed procedures. The ability to accurately diagnose the reasons for failure and treat them must increase as well. Operating surgeons must be diligent in their diagnosis and indications to achieve optimal results with this procedure. Future studies will help determine new avenues of treatment. References 1. Burman M. Arthroscopy or the direct visualization of joints: an experimental cadaver study. J Bone Joint Surg. 1931; 29: McCarthy JC, Lee JA. The role of hip arthroscopy: useful adjunct or devil s tool? Orthopedics. 2002; 25(9): Kelly BT, Williams RJ III, Philippon MJ. Hip arthroscopy: current indications, treatment options, and management issues. Am J Sports Med. 2003; 31(6): McCarthy JC, Lee JA. Arthroscopic intervention in early hip disease. Clin Orthop Relat Res. 2004; (429): Jerosch, J, Schunck J, Khoja A. Arthroscopic treatment of the hip in early and midstage degenerative joint disease. Knee Surg Sports Traumatol Arthrosc. 2006; 14(7): O Leary J, Berend AK, Vail TP. The relationship between diagnosis and outcome in arthroscopy of the hip. Arthroscopy. 2001; 17(2): Philippon MJ, Schenker ML, Briggs KK, Maxwell RB. Can microfracture produce repair tissue in acetabular chondral defects [published online ahead of print November 5, 2007]? Arthroscopy. 2008; 24(1): Horisberger M, Brunner A, Herzog RF. Arthroscopic treatment of femoral acetabular impingement in patients with preoperative generalized degenerative changes [published online ahead of print February 11, 2010]. Arthroscopy. 2010; 26(5): 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): 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: Kim KC, Hwang DS, Lee CH, Kwon ST. Influence of femoroacetabular impingement on results of hip arthroscopy in patients with 616 ORTHOPEDICS Healio.com/Orthopedics

6 Failed Hip Arthroscopy Ward et al early osteoarthritis. Clin Orthop Relat Res. 2007; 456: Ruhmann O. Arthroscopy of the hip joint: indication, technique, results. Dtsch Arztebl Int. 2008; 105(33): Byrd JW, Jones KS. Prospective analysis of hip arthroscopy with 10-year followup. Clin Orthop Relat Res. 2010; 468(3): Byrd JW, Jones KS. Hip arthroscopy in the presence of dysplasia. Arthroscopy. 2003; 19(10): Wenger DE, Kendell KR, Miner MR, Trousdale RT. Acetabular labral tears rarely occur in the absence of bony abnormalities. Clin Orthop Relat Res. 2004; 426: Farjo LA, Glick JM, Sampson TG. Hip arthroscopy for acetabular labral tears. Arthroscopy. 1999; 15(2): Heyworth BE, Shindle MK, Voos JE, Rudzki JR, Kelly BT. Radiologic and intraoperative findings in revision hip arthroscopy. Arthroscopy. 2007; 23(12): Parvizi J, Bican O, Bender B, et al. Arthroscopy for labral tears in patients with developmental dysplasia of the hip: a cautionary note. J Arthroplasty. 2009; 24(6 suppl): Philippon MJ, Schenker ML, Briggs KK, Kuppersmith DA, Maxwell RB, Stubbs AJ. Revision hip arthroscopy [published online ahead of print August 16, 2007]. Am J Sports Med. 2007; 35(11): Ganz R, Klaue K, Vinh TS, Mast JW. A new periacetabular osteotomy for the treatment of hip dysplasias. Technique and preliminary results. Clin Orthop Relat Res. 1988; 232: Ganz, R, Parvizi J, Beck M, Leunig M, Nötzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res. 2003; 417: Larson CM, Giveans MR. Arthroscopic management of femoroacetabular impingement: early outcomes measures. Arthroscopy. 2008; 24(5): Javed A, O Donnell JM. Arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement in patients over 60 years of age. J Bone Joint Surg Br. 2011; 93(3): McCarthy JC, Jarrett BT, Ojeifo O, Lee JA, Bragdon CR. What factors influence longterm survivorship after hip arthroscopy? Clin Orthop Relat Res. 2011; 469(2): Streich NA, Gotterbarm T, Barié A, Schmitt H. Prognostic value of chondral defects on the outcome after arthroscopic treatment of acetabular labral tears [published online ahead of print June 30, 2009]. Knee Surg Sports Traumatol Arthrosc. 2009; 17(10): Londers J, Van Melkebeek J. Hip arthroscopy: outcome and patient satisfaction after 5 to 10 years. Acta Orthop Belg. 2007; 73(4): Ferguson SJ, Bryant JT, Ganz R, Ito K. The acetabular labrum seal: a poroelastic finite element model. Clin Biomech (Bristol, Avon). 2000; 15(6): Ferguson SJ, Bryant JT, Ganz R, Ito K. An in vitro investigation of the acetabular labral seal in hip joint mechanics. J Biomech. 2003; 36(2): Espinosa N, Rothenfluh DA, Beck M, Ganz R, Leunig M. Treatment of femoro-acetabular impingement: preliminary results of labral refixation. J Bone Joint Surg Am. 2006; 88(5): Philippon MJ. New frontiers in hip arthroscopy: the role of arthroscopic hip labral repair and capsulorrhaphy in the treatment of hip disorders. Instr Course Lect. 2006; 55: Larson CM, Giveans MR. Arthroscopic debridement versus refixation of the acetabular labrum associated with femoroacetabular impingement. Arthroscopy. 2009; 25(4): McCarthy JC, Lee JA. Hip arthroscopy: indications, outcomes, and complications. Instr Course Lect. 2006; 55: Byrd JW. Hip arthroscopy. J Am Acad Orthop Surg. 2006; 14(7): Sampson TG. Complications of hip arthroscopy. Clin Sports Med. 2001; 20(4): Clarke MT, Arora A, Villar RN. Hip arthroscopy: complications in 1054 cases. Clin Orthop Relat Res. 2003; 406: Griffin DR, Villar RN. Complications of arthroscopy of the hip. J Bone Joint Surg Br. 1999; 81(4): Scher DL, Belmont PJ Jr, Owens BD. Case report: osteonecrosis of the femoral head after hip arthroscopy. Clin Orthop Relat Res. 2010; 468(11): Simpson J, Sadri H, Villar R. Hip arthroscopy technique and complications. Orthop Traumatol Surg Res. 2010; 96(8 suppl):s68-s Sharma A, Sachdev H, Gomillion M. Abdominal compartment syndrome during hip arthroscopy. Anaesthesia. 2009; 64(5): Fowler J, Owens BD. Abdominal compartment syndrome after hip arthroscopy. Arthroscopy. 2010; 26(1): JULY 2012 Volume 35 Number 7 617