Alexander E. Weber

An Algorithmic Approach to the Management of Recurrent Lateral Patellar Dislocation

High-level evidence supports nonoperative treatment for first-time lateral acute patellar dislocations. Surgical intervention is often indicated for recurrent dislocations. Recurrent instability is often multifactorial and can be the result of a combination of coronal limb malalignment, patella alta, malrotation secondary to internal femoral or external tibial torsion, a dysplastic trochlea, or disrupted and weakened medial soft tissue, including the medial patellofemoral ligament (MPFL) and the vastus medialis obliquus. MPFL reconstruction requires precise graft placement for restoration of anatomy and minimal graft tension. MPFL reconstruction is safe to perform in skeletally immature patients and in revision surgical settings. Distal realignment procedures should be implemented in recurrent instability associated with patella alta, increased tibial tubercle-trochlear groove distances, and lateral and distal patellar chondrosis. Groove-deepening trochleoplasty for Dejour type-B and type-D dysplasia or a lateral elevation or proximal recession trochleoplasty for Dejour type-C dysplasia may be a component of the treatment algorithm; however, clinical outcome data are lacking. In addition, trochleoplasty is technically challenging and has a risk of substantial complications.

Tibial and Femoral Tunnel Changes After ACL Reconstruction A Prospective 2-Year Longitudinal MRI Study

Background: Tunnel widening after anterior cruciate ligament reconstruction (ACL-R) is a well-accepted and frequent phenomenon, yet little is known regarding its origin or natural history. Purpose: To prospectively evaluate the cross-sectional area (CSA) changes in tibial and femoral bone tunnels after ACL-R with serial MRI. Study Design: Case series; Level of evidence, 4. Methods: Patients underwent arthroscopic ACL-R with the same surgeon, surgical technique, and rehabilitation protocol. Each patient underwent preoperative dual-energy x-ray absorptiometry and clinical evaluation, as well as postoperative time zero MRI followed by subsequent MRI and clinical examination, including functional and subjective outcome tests, at 6, 12, 24, 52, and 104 weeks. Tibial and femoral tunnel CSA was measured on each MRI at tunnel aperture (ttA and ftA), midsection (ttM and ftM), and exit (ttE and ftE). Logistic regression modeling was used to examine the predictive value of demographic data and preoperative bone quality (as measured by dual-energy x-ray absorptiometry) on functional outcome scores, manual and instrumented laxity measurements, and changes in tunnel area over time. Results: Eighteen patients (including 12 men), mean age 35.5 ± 8.7 years, underwent ACL-R. There was significant tunnel expansion at ttA and ftA sites 6 weeks postoperatively (P = .024 and .0045, respectively). Expansion continued for 24 weeks, with progressive tunnel narrowing thereafter. Average ttA CSA was significantly larger than ftA CSA at all times. The ttM significantly expanded after 6 weeks (P = .06); continued expansion to week 12 was followed by 21 months of reduction in tunnel diameter. The ftM and both ttE and ftE sites decreased in CSA over the 2 years. Median Lysholm and International Knee Documentation Committee scores significantly improved at final follow-up (P = .0083 and <.0001, respectively), and patients returned to preoperative activity levels. Pivot shift significantly decreased (P < .0001). Younger age (<30 years), male sex, and delayed ACL-R (>1 year from time of injury) predicted increased tunnel widening and accelerated expansion in CSA (P < .005). Conclusion: Tunnel expansion after ACL-R occurs early and primarily at the tunnel apertures. Expansion may not affect clinical outcome. Younger age, male sex, and delay from injury to ACL-R may be potential risks for enlargement.

Complications in Hip Arthroscopy: A Systematic Review and Strategies for Prevention.

The primary objective of this study was to determine the minor and major complication rate of hip arthroscopy. The secondary objective was to provide strategies for avoiding complications. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Therapeutic hip arthroscopy investigations that reported on adverse events or complications were included. Narrative and other systematic reviews, meta-analyses, conference abstracts or proceedings, and level V evidence studies were excluded. No follow-up minimum was imposed. The results yielded 53 studies (8189 hip arthroscopies in 8071 subjects). Most studies were level IV evidence (74%) with a mean of 2.2±2.1 years follow-up. Femoroacetabular impingement (FAI) and labral pathology were the 2 most common indications for surgery, and osteochondroplasty for FAI and labral treatment were the 2 most common procedures performed. The minor and major complication rates were 7.9% and 0.45%, respectively. Iatrogenic chondrolabral damage and temporary nerve injury were the 2 most common minor complications. Extra-articular fluid extravasation was the most common major complication encountered. Minor complications associated with hip arthroscopy are generally technical in nature and may be related to the learning curve associated with hip arthroscopy. As surgeon experience increases and patient selection improves, a corresponding decline should be observed in minor complications. Strategies to prevent complications include careful preoperative planning, appropriate surgical indications, attention to detail in the operating room, and proper postoperative rehabilitation.

The biomechanics of throwing: simplified and cogent.

The majority of shoulder injuries occur due to repetitive overhead movements, with baseball pitching being the most common mechanism for overuse injury. Before studying the treatment of these shoulder injuries, it is paramount that the health professional have an understanding of the etiology of and the underlying mechanisms for shoulder pathology. The act of overhead throwing is an eloquent full-body motion that requires tremendous coordination from the time of force generation to follow-through. The shoulder complex is a crucial component of the upper body kinetic chain as it transmits force created in the lower body to the arm and hand to produce velocity and accuracy with ball release. The focus of this article is on the biomechanics of the throwing motion, with emphasis on the kinematics of the shoulder. The established phases of the throwing motion will be reviewed in a stepwise manner and the contributions of osseous and soft-tissue structures to the successful completion of each phase will be discussed.

The approach to the evaluation and surgical treatment of mechanical hip pain in the young patient: AAOS exhibit selection.

The mechanical causes of hip pain in a young athlete often reflect a complex combination of static and dynamic factors. A comprehensive diagnostic approach is paramount to the development of a rational treatment strategy that will address all underlying pathologic factors. The goals of this paper are to highlight the pertinent biomechanical factors of the hip joint in femoroacetabular impingement and to discuss the clinical history, physical examination, and radiographic findings that are essential to formulating a proper diagnosis and an effective treatment plan. In addition, the current literature and reported outcomes of femoroacetabular impingement surgery in athletic patients are reviewed.

Relevance of Bone Anomalies in Patients with Thoracic Outlet Syndrome

BACKGROUND Skeletal anomalies are recognized as potential causes of thoracic outlet syndrome (TOS); however, there is a paucity of information regarding the specific bone anomalies associated with TOS and their relative incidence among the different clinical types of TOS. This study describes the prevalence of bone anomalies in a population with TOS. METHODS A retrospective chart review of the clinical records and imaging studies of all patients who were surgically treated at our institution for TOS between 1991-2011 was conducted. A descriptive analysis of the cohort of patients with associated bone anomalies was performed and compared with the cohort of patients without bone anomalies. RESULTS During the study period, 400 patients underwent operative procedures for TOS. Of these, 115 (29%) harbored a bone anomaly and the remaining 285 did not. The bone anomalies included 80 (69%) cervical ribs, 25 (22%) clavicular anomalies, and 10 (9%) isolated first rib aberrations. Ninety (78%) of the bone anomalies were congenital, while 25 (22%) were posttraumatic. The bone anomaly cohort was predominantly female (76%), with an average age of 36 years. The distribution of neurogenic, arterial, and venous types of TOS in the cohort with bone anomalies was 63%, 33%, and 4%, respectively, while it was 51% neurogenic, 11% arterial, and 38% venous in the cohort without bone anomalies. These distributions were significantly different (chi-squared: 56.75; P < 0.0001). The likelihood of neurogenic compression was roughly equivalent between the 2 cohorts (odds ratio [OR]: 1.6; P = 0.03), while the likelihood of arterial compression was much higher in the presence of a bone anomaly (OR: 4.0; P < 0.001) and the likelihood of venous compression was much lower in the presence of bone anomaly (OR: 0.07; P < 0.001). Conversely, 33% of all neurogenic TOS cases, 54% of all arterial TOS cases, and 4% of all venous TOS cases were associated with a bone anomaly. CONCLUSIONS In our experience, the incidence of bone anomalies among patients treated for TOS was 29%, which is higher than previously reported. Cervical ribs were present in 20% of our patients with TOS, an estimated 40 times higher prevalence than that in the general population. However, acquired clavicular deformities and isolated abnormal first ribs were found in 9% of our patients, accounting for almost one-third of all bone anomalies present in this TOS population. The incidence of bone anomalies is rather different among the subtypes of TOS. The strongest association with the presence of a bone anomaly occurs in patients with arterial TOS, although 46% of all our arterial TOS cases did not have a bone anomaly. The presence of bone anomalies does not seem to influence the occurrence of neurogenic TOS, while venous TOS likely has no association with congenital bone anomalies, but occasionally mid and medial clavicular fracture calluses may cause venous TOS.

Clinically Meaningful Improvements After Hip Arthroscopy for Femoroacetabular Impingement in Adolescent and Young Adult Patients Regardless of Gender

Background: The objective of this study was to determine if adolescent and young adult patients undergoing hip arthroscopy for symptomatic femoroacetabular impingement (FAI) experience clinically meaningful improvements in functional outcome scores. Methods: A consecutive series of patients under age 18 who underwent primary hip arthroscopy for symptomatic FAI was identified using our institution’s hip registry. Demographics, preoperative radiographic measurements, and preoperative and postoperative patient-reported outcome scores [Hip Outcome Score (HOS), Activity of Daily Living (ADL), and Sports-Specific Subscale (SS), and modified Harris Hip Score (MHHS)] were collected. Percentage of patients achieving minimum clinically important difference (MCID) and patient acceptable symptom state (PASS) were determined using published cutoffs for HOS and MHHS in FAI patients. Results: Forty-three patients met study inclusion criteria, and 37 patients (86%) were available at a minimum follow-up of 2 years. Mean age was 17.0±1.4 years, 70% were female, and 8.1% had an open proximal femoral physis. All competitive high school and college athletes were able to return to sport. Patients experienced significant improvements following hip arthroscopy in HOS-ADL, HOS-SS, and MHHS scores (all P<0.0001). MCID was achieved in 81% of patients (27/34) for HOS-ADL, 97% (33/34) for HOS-SS, and 84% (27/32) for MHHS. PASS was achieved for 76% of patients (26/34) for HOS-ADL, 79% (27/34) for HOS-SS, and 81% (26/32) for MHHS. Lower body mass index but not age or sex was correlated with a greater improvement in MHHS scores (r=0.39; P=0.03). There were 2 minor complications and no revision surgery. Conclusions: Adolescent and young adult patients experienced statistically significant improved functional outcomes 2 years after hip arthroscopy for FAI. In addition, these outcomes can be achieved with a low complication rate and a high return to preoperative activity. Approximately 80% of patients achieved clinically significant outcomes based on MCID and PASS criteria. Patient improvements in MHHS were equal regardless of age or sex; however, lower preoperative body mass index led to greater postoperative MHHS improvements. Level of Evidence: Level IV—therapeutic case series.

The Natural History of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis (OA); however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to OA. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing OA and the need for future arthroplasty.

A review of imaging modalities for the hip

Hip arthroscopy is one of the fastest growing surgical procedures performed by orthopaedic surgeons, with the number of hip arthroscopies expected to double in 2013. The increase in surgical prevalence is at least in part due to an increased awareness of prearthritic hip pathology. The diagnoses of prearthritic hip conditions are made through a comprehensive history, physical examination, and selection of appropriate diagnostic imaging modalities. The purpose of this review article is to provide the practicing orthopaedic surgeon with an overview of the imaging modalities available for the diagnosis of prearthritic hip pathology, with a focus on literature supporting advancements in imaging techniques and new applications of existing modalities.

The Hyperflexible Hip Managing Hip Pain in the Dancer and Gymnast

Context: Dance, gymnastics, figure skating, and competitive cheerleading require a high degree of hip range of motion. Athletes who participate in these sports use their hips in a mechanically complex manner. Evidence Acquisition: A search of the entire PubMed database (through December 2013) and additional searches of the reference lists of pertinent articles. Study Design: Systematic review. Level of Evidence: Level 3. Results: Whether innate or acquired, dancers and gymnasts have some hypermobility that allows their hips to be placed in potentially impinging or unstable positions required for their given activity. Such extremes of motion can result in both intra-articular and extra-articular impingement as well as compensatory osseous and muscular pathology. In addition, dancers and gymnasts are susceptible to impingement-induced instability. Dancers with innate generalized hyperlaxity are at increased risk of injury because of their activities and may require longer recovery times to return to play. Both nonoperative and operative treatments (arthroscopic and open) have an important role in returning flexibility athletes to their preoperative levels of sport and dance. Conclusion: Because of the extreme hip motion required and the compensatory soft tissue laxity in dancers and gymnasts, these athletes may develop instability, impingement, or combinations of both. This frequently occurs in the setting of subtle pathoanatomy or in patients with normal bony anatomy. With appropriate surgical indications and the correct operative technique, the treating surgeon can anticipate high levels of return to play for the gymnast and dancer with hip pain.