Editorial Commentary: More Evidence That Some Sports Are Harder on Hips Than Others.

Femoroacetabular impingement (FAI) is generally agreed to be one of the main causes of hip osteoarthritis later in life. There is a strong association between certain sports and hip arthroscopy with labral repair and osteochondroplasty for FAI. Some sports, such as ice hockey, soccer, and basketball, place substantial mechanical demands on the hip, thus causing more hip injuries in athletes who participate in them. Sports medicine physicians caring for athletes playing "hip-intense" sports should have a low index of suspicion for FAI, even if the initial injury is described only as a groin strain. In addition, evidence is accumulating that sports-related pressure on the femoral physis during closure causes cam deformity and resultant FAI. Although this may be unpopular with coaches and parents, orthopaedists as a group should begin to research and advocate preventive measures including likely activity limitations for adolescent athletes playing these sports.

The demographic characteristics of high-level and recreational athletes undergoing hip arthroscopy for femoroacetabular impingement: a sports-specific analysis.

PURPOSE: The purpose of this study was to determine differences in age, gender, and the need for bilateral surgery between high-level athletes grouped by sports with similar mechanical demands on the hip and recreational athletes undergoing hip arthroscopy for femoroacetabular impingement (FAI). METHODS: By use of a hip-preservation center registry, a retrospective review of patients undergoing hip arthroscopy for FAI between March 2010 and April 2012 was performed. Athletes were categorized as high level (high school, collegiate, or professional) or recreational. We performed a subgroup analysis for high-level athletes, looking at differences among contact, cutting, impingement, overhead/asymmetric, endurance, and flexibility sports. RESULTS: The study included 288 high-level athletes and 334 recreational athletes. Being a high-level athlete was associated with a younger age (mean age, 20.2 years v 33.0 years; odds ratio, 0.69; P < .001) and male gender (61.5% v 53.6%; odds ratio, 1.75; P = .03). The percentage of high-level athletes undergoing bilateral surgery was higher than that of recreational athletes (28.4% v 15.9%); however, this association was found to be confounded by age on multivariate analysis. The most common sports for high-level athletes were soccer, hockey, and football. Athletes participating in cutting sports were significantly younger than athletes participating flexibility, contact, or impingement sports. CONCLUSIONS: When compared with recreational athletes undergoing arthroscopic treatment for FAI, high-level athletes are more likely to be younger, to be male, and to undergo bilateral surgery. When high-level athletes are grouped by the mechanical demands placed on the hip by their sport, athletes participating in cutting sports are more likely to be younger than those in the other groups. LEVEL OF EVIDENCE: Level IV, case series.

Pros and cons of surgical hip dislocation for the treatment of femoroacetabular impingement.

A more detailed understanding of the anatomy of the medial femoral circumflex artery enabled the development of the modern technique for surgical hip dislocation. Although the surgical hip dislocation is best known as an open method for treating femoroacetabular impingement, it allows the surgeon to address a variety of different hip pathologies, including femoral head and posterior wall acetabular fractures, chondral defects requiring cartilage restoration techniques, and excision of benign tumors. When the technique of an extended retinacular flap is added, surgeons are able to perform intra-articular osteotomies and open reduction of slipped capital femoral epiphysis while preserving the blood supply to the femoral head. The surgical hip dislocation allows direct observation of both intra-articular and extra-articular impingement and a means of correcting both during 1 procedure. The downsides of the surgical hip dislocation are largely related to the trochanteric flip osteotomy, with up to half of patients reporting mild residual lateral hip pain 1 year postoperatively. Trochanteric nonunion and residual abductor weakness are also potential complications of the surgical hip dislocation technique. Several studies have shown improved pain and functional outcomes in short-term and mid-term follow-up after treatment of femoroacetabular impingement. It has a low complication rate in the hands of experienced surgeons and is an important technique for addressing complex intra-articular hip pathology that would be technically challenging arthroscopically.

Risks and benefits of the modified Dunn approach for treatment of moderate or severe slipped capital femoral epiphysis.

In North America, in situ pinning is the most common treatment for a stable slipped capital femoral epiphysis (SCFE), with generally good results and relatively low risk of avascular necrosis. Since the recognition that even a mild SCFE can cause femoroacetabular impingement, there has been a reconsideration of the goals of treatment, particularly for moderate, severe, or unstable slips. The modified Dunn approach for moderate or severe SCFE involves a surgical hip dislocation, creation of a retinacular flap, controlled open reduction of the epiphysis, and internal fixation of the slip. It has the advantage of correcting the pathoanatomy at the site of the deformity and at the time of diagnosis, minimizing secondary chondrolabral damage. The short-term results are generally good to excellent with few complications. The modified Dunn technique is, however, technically complex and more invasive than in situ pinning, with some inherent risk of avascular necrosis because of the proximity to the lateral retinacular vessels. When performed by experienced surgeons, the modified Dunn technique is an ideal technique for the treatment of moderate to severe SCFE. Because of the technically challenging nature of the procedure, it is recommended that it be performed in tertiary care centers by surgeons with experience in this technique.

Anteroinferior acetabular rim damage due to femoroacetabular impingement.

BACKGROUND: The most common location of labral tears and chondral damage in the hip is the anterosuperior region of the acetabulum, which is associated with pain in flexion and rotation. We describe a case series of patients with labral tears, ganglion formation, and chondromalacia isolated to the anteroinferior acetabulum. Clinically, patients had pain in extension and internal rotation. CASE DESCRIPTIONS: Isolated anteroinferior labral hypertrophy and ganglion were first observed in a patient with coxa valga. We retrospectively reviewed clinical and radiographic records and identified nine hips in seven patients with isolated anteroinferior damage. One patient with bilateral valgus femoral head tilt after slipped capital femoral epiphysis (SCFE) had impingement of the anteromedial metaphysis on the acetabulum from 3 to 6 o'clock. Five of seven had valgus neck-shaft angles and all had acetabular anteversion with damage isolated to the anteroinferior acetabular rim. LITERATURE REVIEW: Series on the diagnostic efficacy of MR arthrogram have noted anteroinferior damage adjacent to superior acetabular rim lesions. However, these do not describe isolated anteroinferior rim damage. In addition, available case series of patients with valgus SCFE do not describe a location of impingement or intraarticular damage. PURPOSES AND CLINICAL RELEVANCE: In this small case series of patients with isolated anteroinferior chondrolabral damage, there are two potential causative mechanisms: (1) primary anteroinferior impingement with femoral extension and internal rotation and (2) posterior extraarticular ischiotrochanteric impingement causing secondary anterior instability of the femur. The pathoanatomy appears to be multifactorial, necessitating an individualized treatment approach.

Two or more impingement and/or instability deformities are often present in patients with hip pain.

BACKGROUND: Damage to the hip can occur due to impingement or instability caused by anatomic factors such as femoral and acetabular version, neck-shaft angle, alpha angle, and lateral center-edge angle (CEA). The associations between these anatomic factors and how often they occur in a painful hip are unclear but if unaddressed might explain failed hip preservation surgery. QUESTIONS/PURPOSES: We determined (1) the influence of sex on the expression of impingement-related or instability-related factors, (2) the associations among these factors, and (3) how often both impingement and/or instability factors occur in the same hip. METHODS: We retrospectively reviewed a cohort of 170 hips (145 patients) undergoing MR arthrography of the hip for any reason. We excluded 58 hips with high-grade dysplasia, Perthes' sequelae, previous surgery, or incomplete radiographic information, leaving 112 hips (96 patients). We measured femoral version and alpha angles on MR arthrograms. Acetabular anteversion, lateral CEA, and neck-shaft angle were measured on pelvic radiographs. RESULTS: We observed a correlation between sex and alpha angle. Weak or no correlations were observed between the other five parameters. In 66% of hips, two or more (of five) impingement parameters, and in 51% of hips, two or more (of five) instability parameters were found. CONCLUSIONS: Patients with hip pain frequently have several anatomic factors potentially contributing to chondrolabral damage. To address pathologic hip loading due to impingement and/or instability, all of the anatomic influences should be known. As we found no associations between anatomic factors, we recommend an individualized assessment of each painful hip.

Periacetabular osteotomy for hip preservation.

The Bernese PAO has now been performed for nearly 30 years. In that time, it has proved itself a technically complex procedure with the potential to considerably improve the natural history of the dysplastic hip. Significant refinements in the surgical technique combined with the recognition of FAI, improvements in the understanding of hip biomechanics and acetabular orientation, and more discerning patient selection have improved the outcomes related to this procedure. Although the recovery can be demanding and the potential for complications exists, the results are reproducible and the technique has become the gold standard for acetabular reorientation.

Surgical technique: Second-generation bone marrow stimulation via surgical dislocation to treat hip cartilage lesions.

BACKGROUND: Compared to knees, hips have more bony constraint and soft tissue coverage. Thus, repair of focal cartilage defects in hips requires more invasive and technically complex surgeries than simple arthroscopy or arthrotomy. Autologous matrix-induced chondrogenesis (AMIC) is a second-generation bone marrow stimulation technique. Improvement in Tegner, Lysholm, International Cartilage Repair Society (ICRS), and Cincinnati scores has been reported at 1 and 2 years after AMIC in knees. AMIC is potentially useful to repair defects in hips, but it is unknown whether it relieves symptoms or results in a durable construct. DESCRIPTION OF TECHNIQUE: A surgical hip dislocation is used to access the defect. This is débrided to stable cartilage shoulders, necrotic bone is removed, and the lesion base is drilled. Autogenous bone graft is used for lesions with bony defects to create a level surface. Fibrin gel and a collagen membrane are placed to stabilize the superclot for fibrocartilage formation. METHODS: We treated six patients with AMIC in the hip between 2009 and 2010. We obtained Oxford Hip and UCLA Activity Scores. Repair quality was assessed on 6-month postoperative MRI using the modified magnetic resonance observation of cartilage repair tissue (MOCART) system. Minimum 1-year followup data were available for four patients (range, 1-2.5 years). RESULTS: Postoperative Oxford Hip Scores ranged from 13 to 17, UCLA Activity Scores ranged from 5 to 10, and MOCART scores ranged from 55 to 75. No complications occurred. CONCLUSIONS: We describe AMIC in the hip. Although these patients had pain relief and improved function, long-term followup is necessary to assess the duration of improvement, durability of repair, and potential for arthrosis. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Glenoid morphology rather than version predicts humeral subluxation: a different perspective on the glenoid in total shoulder arthroplasty.

BACKGROUND: Glenoid retroversion is thought be important in shoulder stability before and after shoulder arthroplasty; thus, many authors recommend glenoid reaming to correct retroversion and improve stability. Genetic analysis has revealed that glenoid vault and scapular development are controlled by different genes and environmental factors, resulting in diverse glenoid morphologies. We therefore analyzed the relative contribution of glenoid morphology and version to humeral head position. MATERIALS AND METHODS: We obtained 121 shoulder computed tomography scans preoperatively for shoulder arthroplasty. Humeral subluxation and glenoid version were measured on the axial image at the middle of each glenoid. Glenoid morphology was characterized as biconcave, worn, displaced, dysplastic, angled, or neutral. The strength of the correlation between humeral subluxation, glenoid version, and glenoid morphology was analyzed. RESULTS: Glenoid version did not correlate with humeral subluxation. The highest frequency of posterior subluxation was noted in biconcave glenoids. Shoulders with other glenoid morphologies were more likely to have anterior or central positioning of the humerus. The mean subluxation ratio for biconcave glenoids was 0.56 and was significantly different from all other morphologies (P < .02). DISCUSSION/CONCLUSION: Even in the arthritic shoulder, glenoid orientation does not appear to explain the complex biomechanics of shoulder stability. The causes of humeral head subluxation before and after total shoulder arthroplasty are likely multifactorial and may include static and dynamic soft-tissue forces. The biconcave glenoid deserves more attention at surgery because of the high association with posterior subluxation.

Labral Resection or Preservation During FAI Treatment? A Systematic Review.

BACKGROUND: Open and arthroscopic treatment of femoroacetabular impingement and resultant labral pathology has increased significantly over the past decade. Although the functional importance of the labrum and the labral seal has been established in biomechanical studies, good clinical results have been reported for both labral debridement and labral refixation. QUESTIONS/PURPOSES: The purpose of this paper is to summarize existing literature on the surgical treatment of labral pathology to provide treatment recommendations and direct future research. A systematic review was performed with the following research question in mind: Does preservation of the hip labrum improve outcomes as compared to labral debridement for the treatment of labral pathology? METHODS: The MEDLINE database was searched for level I, II, or III articles in English or German comparing labral debridement to labral refixation. Five studies were included in the analysis. RESULTS: Good short-term results were reported for both groups. Three out of five papers report improved outcomes after labral refixation as compared to labral debridement. CONCLUSIONS: In short-term follow-up, labral refixation appears to have slightly better outcomes than labral debridement. Studies with prospectively defined cohorts and longer follow-up are, however, necessary to provide definitive recommendations for labral treatment.

A quantitative three-dimensional templating method for shoulder arthroplasty: biomechanical validation in cadavers.

BACKGROUND: Press-fit humeral components for total shoulder arthroplasty have notable potential complications that may be minimized by preoperative templating and improvements in stem design. The purpose of this study was to develop a 3-dimensional templating technique for the humeral stem and to validate this templating in cadaveric specimens. MATERIALS AND METHODS: A cylindrical stem and a stem with a rectangular cross-section were selected for templating and force measurements. Templating was carried out for 15 clinical patients and 16 cadaveric shoulders, including calculation of the cortical-implant volume ratio (CIVR). Insertion forces for stem broaching and impaction were measured for 15 patients and 8 paired cadaveric shoulders. Hoop strain and periprosthetic fractures were monitored in cadaveric shoulders with strain gauges. RESULTS: A significant difference in the CIVR was noted between rectangular and cylindrical stems. No difference was observed in impact forces for ideally sized rectangular or cylindrical stems. A difference in insertion forces was found between oversized cylindrical and oversized rectangular implant stems and also between ideal and oversized cylindrical implant stems. The difference in maximal hoop strain between ideally sized rectangular and cylindrical stems was also statistically significant. CONCLUSIONS: CIVR is useful to predict an ideal humeral stem size. Cylindrical stems have a different design rationale for fixation than rectangular stems. Surgeon awareness of the fixation rationale for a particular stem design is important because different stem types have different effects on the insertion force. More anatomic humeral stem designs may help to minimize the risk of complications and optimize stem fixation.

Differential diagnosis of pain around the hip joint.

The differential diagnosis of hip pain is broad and includes intra-articular pathology, extra-articular pathology, and mimickers, including the joints of the pelvic ring. With the current advancements in hip arthroscopy, more patients are being evaluated for hip pain. In recent years, our understanding of the functional anatomy around the hip has improved. In addition, because of advancements in magnetic resonance imaging, the diagnosis of soft tissue causes of hip pain has improved. All of these advances have broadened the differential diagnosis of pain around the hip joint and improved the treatment of these problems. In this review, we discuss the causes of intra-articular hip pain that can be addressed arthroscopically: labral tears, loose bodies, femoroacetabular impingement, capsular laxity, tears of the ligamentum teres, and chondral damage. Extra-articular diagnoses that can be managed arthroscopically are also discussed, including: iliopsoas tendonitis, "internal" snapping hip, "external" snapping hip, iliotibial band and greater trochanteric bursitis, and gluteal tendon injury. Finally, we discuss extra-articular causes of hip pain that are often managed nonoperatively or in an open fashion: femoral neck stress fracture, adductor strain, piriformis syndrome, sacroiliac joint pain, athletic pubalgia, "sports hernia," "Gilmore's groin," and osteitis pubis.