Faculty Bibliography

Bone marrow edema of the knee occurs secondary to a myriad of causes. The hallmark of a bone marrow lesion (BML) is an area of decreased signal intensity on T1 weighted MRI with a corresponding area of increased signal intensity on a T2 weighted MRI. Recently, chronic bone marrow lesions have been correlated with knee pain and progression of osteoarthritis. These lesions have also been associated with other degenerative conditions such as meniscal tears, cartilage deterioration, subchondral cyst formation, mechanical malalignment, and ultimately progression to arthroplasty. Medical treatments, such as prostacyclin and bisphosphonate therapy, have shown promise. Alignment procedures, as well as core decompression and subchondroplasty, have been used as surgical treatments for chronic BMLs.

Greater trochanteric pain syndrome (GTPS) is a term used to describe disorders of the peritrochanteric region. This constellation of conditions includes greater trochanteric bursitis, gluteus medius (GM) tears, and external coxa saltans or snapping hip syndrome. Tears of the abductor mechanism, more specifically gluteus medius tears, have recently gained a considerable amount of interest in the orthopaedic literature. Abductor tears were first described by Bunker and Kagan in the late 1990s. They used the rotator cuff as an analogous structure to describe the pathological process associated with gluteus medius tears. Tears of the gluteus medius tendon can often be difficult to recognize. The clinical presentation is often attributed to trochanteric bursal inflammation, without any further workup. Provocative hip physical examination findings are an important key to proper diagnosis of abductor injuries. Depending on the size of the tear, patients with abductor tendon pathology may present with a Trendelenburg gait and reduced resisted abduction strength accompanied by pain. Initial noninvasive management of greater trochanteric pain syndrome includes oral or topical anti-inflammatory medication and activity modification. Physical therapy or other treatment modalities can be considered, with a focus on core strengthening, truncal alignment, and iliotibial band stretching. Gluteus medius tears have historically been repaired in an open fashion; however, the advent of new endoscopic surgery techniques has allowed for a less invasive approach. Access to the peritrochanteric space affords the surgeon with access to pathology associated with the greater trochanter, iliotibial band, trochanteric bursa, sciatic nerve, short external-rota tors, iliopsoas tendon, and the gluteus medius and minimus tendon attachments. Over the last decade, we have seen rapid technological advances in hip arthroscopy, improved diagnostic imaging and interpretation, and an improved understanding of intra-articular and peritrochanteric hip pathology. As the emphasis on hip arthroscopy in residency and fellowship training programs continues to increase, the learning curve for endoscopic management of peritrochanteric disorders will continue to improve.

BACKGROUND: Injury to subchondral bone is associated with knee pain and osteoarthritis (OA). A percutaneous calcium phosphate injection is a novel approach in which subchondral bone marrow edema lesions are percutaneously injected with calcium phosphate. In theory, calcium phosphate provides structural support while it is gradually replaced by bone. However, little clinical evidence supports the efficacy of percutaneous calcium phosphate injections. QUESTIONS/PURPOSES: We asked: (1) Does percutaneous calcium phosphate injection improve validated patient-reported outcome measures? (2) What proportion of patients experience failure of treatment (defined as a low score on the Tegner Lysholm Knee Scoring Scale)? (3) Is there a relationship between outcome and age, sex, BMI, and preoperative grade of OA? METHODS: Between September 2012 and January 2014, we treated 33 patients with percutaneous calcium phosphate injections. Twenty-five satisfied our study inclusion criteria; of those, three patients were lost to followup and 22 (88%; 13 men, nine women) with a median age of 53.5 years (range, 38-70 years) were available for retrospective chart review and telephone evaluation at a minimum of 6 months (median, 12 months; range, 6-24 months). Our general indications for this procedure were the presence of subchondral bone marrow edema lesions observed on MR images involving weightbearing regions of the knee associated with localized pain on weightbearing and palpation and failure to respond to conservative therapy (> 3 months). Patients with pain secondary to extensive nondegenerative meniscal tears with a flipped displaced component at the level of bone marrow edema lesions, or with mechanical axis deviation greater than 8 degrees were excluded. All patients had Grades III or IV chondral lesions (modified Outerbridge grading system for chondromalacia) overlying MRI-identified subchondral bone marrow edema lesions. Percutaneous calcium phosphate injection was performed on the medial tibial condyle (15 patients), the medial femoral condyle (five patients), and the lateral femoral condyle (two patients). Concomitant partial meniscectomy was performed in 18 patients. Preoperative and postoperative scores from the Knee Injury and Arthritis Outcome Score (KOOS) and the Tegner Lysholm Knee Scoring Scale were analyzed. RESULTS: For patients available for followup, the outcome scores improved after treatment. The KOOS improved from a mean of 39.5 +/- 21.8 to 71.3 +/- 23 (95% CI, 18.6-45.2; p < 0.001) and the Tegner and Lysholm score from 48 +/- 15.1 to 77.5 +/- 20.6 (95% CI, 18.8-40.2; p < 0.001). However, seven of the 22 patients had poor clinical outcomes as assessed by the Tegner Lysholm Knee Scoring Scale, whereas three had fair results, five had good results, and seven had excellent results. The postoperative Tegner Lysholm score was inversely related to the preoperative Kellgren-Lawrence OA grade (R2 = 0.292; F (1.20) = 9.645; p = 0.006). We found no relationship between outcome scores and age, sex, or BMI. CONCLUSIONS: In a study that would have been expected to present a best-case analysis (short-term followup, loss to followup of patients with potentially unsatisfactory results, and use of invasive cotreatments including arthroscopic debridements), we found that percutaneous calcium phosphate injection in patients with symptomatic bone marrow edema lesions of the knee and advanced OA yielded poor results in a concerning proportion of our patients. Based on these results, we advise against the use of percutaneous calcium phosphate injections for patients with advanced osteoarthritic changes. LEVEL OF EVIDENCE: Level IV, therapeutic study.

PURPOSE: Given the potential for injury due to joint-distraction techniques during hip arthroscopy, this study investigated the outcomes and safety of traction during hip arthroscopy in a series of patients with a prior lower-extremity arthroplasty. METHODS: Nine patients with a prior hip or knee arthroplasty (Group 1) and a matched cohort of nine additional patients with no prior hip surgery (Group 2) who underwent hip arthroscopy with traction between 2011 and 2013 were evaluated. Collected data included traction and operative times, Modified Harris Hip Scores (MHHS), Non-Arthritic Hip Scores (NAHS), and postoperative complications. RESULTS: Both operative (p = 1) and traction (p = 0.11) times were similar in each group. Each group had a significant improvement in MHHS from baseline to final follow-up: from 39 to 73 (p < 0.001) in Group 1 and from 49 to 75 (p = 0.03) in Group 2. Similarly, the NAHS showed significant improvement in each group from baseline to final follow-up: from 41 to 71 (p < 0.001) in Group 1 and from 48 to 74 (p = 0.02) in Group 2. There was no difference between groups in MHHS or NAHS. There was one postoperative complication in Group 1 (a recurrent labral tear) and no complications from an existing arthroplasty or in Group 2. CONCLUSIONS: Hip arthroscopy in patients with a lower-extremity arthroplasty yields improved short-term clinical outcomes without increased complications. The use of traction during hip arthroscopy is safe in this population.

PURPOSE: This study aimed to evaluate patient-reported outcomes and complications after hip arthroscopy in an obese population compared with a matched nonobese control group with a minimum 2-year follow-up, using the Modified Harris Hip Score (MHHS) and Nonarthritic Hip Score (NAHS). METHODS: Data were analyzed from 21 consecutive obese patients (body mass index [BMI] >/= 30) and 18 nonobese patients (BMI < 25) who underwent hip arthroscopy between 2009 and 2012 with a minimum follow-up of 2 years. Data collected included MHHS, NAHS, traction and intraoperative times, and postoperative complications. RESULTS: Traction times were similar between obese and nonobese patients at 48 and 45 minutes (P = .51), respectively. Operative times were also similar at 54 and 51 minutes (P = .79), respectively. Each group had a statistically significant improvement in MHHS from baseline to final follow-up: 45 to 79 (P < .001) in the obese group and 49 to 81 (P < .001) in the nonobese cohort. Similarly, the NAHS showed significant improvement in each group from baseline to final follow-up: 43 to 75 (P < .001) in the obese cohort and 45 to 83 (P < .001) in the nonobese group. There was no difference between groups in MHHS or NAHS data. There were 8 complications in the obese group, most commonly deep vein thrombosis (DVT) and worsened pain, whereas the nonobese cohort had one complication (an instance of heterotopic ossification [HO]). Overall, obese patients had 11.1 times the risk of a complication developing than did nonobese patients (95% confidence interval, 1.2 to 99.7). CONCLUSIONS: Hip arthroscopy in the obese patient population leads to improved short- to mid-term patient-reported outcomes similar to those seen in nonobese patients. Obese patients, however, are at a significantly increased risk of postoperative complications such as DVTs and worsened hip pain. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

BACKGROUND:This is a systematic review to determine if prophylactic surgical intervention for asymptomatic patients with radiographic evidence of femoroacetabular impingement (FAI) is warranted to prevent early degenerative joint disease of the hip. METHODS:A systematic search was performed from 1965 to 2013 in PubMed and EMBASE. Inclusion criteria were prospective or retrospective studies comparing skeletally mature asymptomatic patients with radiographic evidence of FAI treated with prophylactic hip arthroscopic surgery versus nonoperative management. A total of 840 references were identified from the searches. After detailed eligibility screening, none of the references met the eligibility criteria. RESULTS:No trials were identified that met the criteria for inclusion in the review. CONCLUSION:There is a lack of available evidence to support surgical intervention for the treatment of FAI in asymptomatic patients. This article attempts to address this dilemma by reviewing the available literature to answer several questions that would indirectly address the topic. First, what is the prevalence of FAI in the asymptomatic population? Second, what is the natural history of FAI if left untreated? Upon reviewing these issues, the authors' conclusion parallels that of the systematic review: Current evidence does not support prophylactic surgery for asymptomatic FAI in the vast majority of cases. However, limited evidence suggests that asymptomatic patients who have previously undergone total hip arthroplasty for FAI-induced osteoarthritis of the contralateral hip are at a significantly increased risk for early degenerative joint disease. Further research is needed to better clarify surgical indications.

The shoulder joint has the greatest range of motion of any joint in the body. However, it relies on soft-tissue restraints, including the capsule, ligaments, and musculature, for stability. Therefore, this joint is at the highest risk for dislocation. Thorough knowledge of the shoulder's anatomy as well as classification of dislocations, anesthetic techniques, and reduction maneuvers is crucial for early management of acute shoulder dislocation. Given the lack of comparative studies on various reduction techniques, the choice of technique is based on physician preference. The orthopaedic surgeon must be well versed in several reduction methods and ascertain the best technique for each patient.

OBJECTIVE: This study aimed at identifying the optimal threshold value to detect cartilage lesions with Standardized dGEMRIC at 3T and evaluate intra- and inter-observer repeatability. DESIGN: We retrospectively reviewed 20 hips in 20 patients. dGEMRIC maps were acquired at 3T along radial imaging planes of the hip and standardized to remove the effects of patient's age, sex and diffusion of gadolinium contrast. Two observers separately evaluated 84 Standardized dGEMRIC maps, both by visual inspection and using an average index for a region of interest in the acetabular cartilage. A radiologist evaluated the acetabular cartilage on morphologic MR images at exactly the same locations. Using intra-operative findings as reference, the optimal threshold to detect cartilage lesions with Standardized dGEMRIC was assessed and results were compared with the diagnostic performance of morphologic MRI. RESULTS: Using z < -2 as threshold and visual inspection of the color-adjusted maps, sensitivity, specificity and accuracy for Observer 1 and Observer 2, were 83%, 60% and 75%, and 69%, 70% and 69%, respectively. Overall performance was 52%, 67% and 58%, when using an average z for the acetabular cartilage, compared to 37%, 90% and 56% for morphologic assessment. The kappa coefficient was 0.76 and 0.68 for intra- and inter-observer repeatability, respectively, indicating substantial agreement. CONCLUSIONS: Standardized dGEMRIC at 3T is accurate in detecting cartilage damage and could improve preoperative assessment in FAI. As cartilage lesions in FAI are localized, visual inspection of the Standardized dGEMRIC maps is more accurate than an average z for the acetabular cartilage.