Faculty Bibliography

MRI has been shown to be both sensitive and specific in the diagnosis of partial thickness and full-thickness tears of the rotator cuff. Recognizing the pattern of a rotator cuff tear before surgery also provides useful information to the referring clinician as it can help in the selection of the type of surgery and lead to a better anatomic and biomechanical restoration of the cuff tendons. There is relative paucity of published reports exploring the performance of MRI in the recognition and classification of rotator cuff tears based on their morphological pattern. The purpose of this exhibit is: 1) to describe the geometric patterns of rotator cuff tears, 2) to illustrate the MR imaging appearance of the different patterns of rotator cuff tearing, 3) to describe the clinical significance of the different patterns in terms of treatment selection and outcome prediction. Characterization of the most common rotator cuff tear patterns will be presented including: crescent-shaped, U-shaped, L-shaped, and massive cuff tears. This will be followed by a guide that can be used to recognize these patterns on MRI utilizing the location as well as the size of the transverse and longitudinal components of the tear on surgically proven cases. Finally, a review of the different types of repairs currently available for each tear pattern will be presented including end-to-bone repair and margin convergence techniques as well as the expected postsurgical outcomes

The rotator cable, an extension of the coracohumeral ligament, is a fibrous band-like structure that courses along the undersurface of the supraspinatus and infraspinatus tendons perpendicular to their tendon fibers. Originally described in the orthopaedic literature, the rotator cable likely plays an important role in the biomechanics of the intact and torn rotator cuff. Published data addressing the performance of MR imaging in the evaluation of the rotator cable is rather limited. The purpose of this exhibit is threefold: 1) to describe the normal gross anatomy, histology, as well as the MR imaging anatomy of the rotator cable, 2) to describe the role of imaging as it pertains to the cable's function in the biomechanics of the intact and torn rotator cuff, 3) to underscore the clinical significance of the cable in terms of classification and treatment of rotator cuff tears. Introduction to the most current knowledge on the origin, distribution, and insertions of the rotator cable using gross anatomy, histology, and MR imaging correlation will be presented. Emphasis will be placed on the MR appearance of the rotator cable in orthogonal imaging planes in both intact and torn rotator cuffs. The role of the rotator cable in the setting of rotator cuff pathology will be underscored using MRI, including its potential contributions to the geometric configuration of cuff tears, altered glenohumeral biomechanics, and fatty degeneration of the rotator cuff musculature. Lastly, a review of the clinical importance of the rotator cable will be provided focused on the effect of the cable's integrity in the management of rotator cuff tears

Mastering rapidly evolving orthopaedic surgical techniques requires a lengthy period of training. Current work-hour restrictions and cost pressures force trainees to face the challenge of acquiring more complex surgical skills in a shorter amount of time. As a result, alternative methods to improve the surgical skills of orthopaedic trainees outside the operating room have been developed. These methods include hands-on training in a laboratory setting using synthetic bones or cadaver models as well as software tools and computerized simulators that enable trainees to plan and simulate orthopaedic operations in a three-dimensional virtual environment. Laboratory-based training offers potential benefits in the development of basic surgical skills, such as using surgical tools and implants appropriately, achieving competency in procedures that have a steep learning curve, and assessing already acquired skills while minimizing concerns for patient safety, operating room time, and financial constraints. Current evidence supporting the educational advantages of surgical simulation in orthopaedic skills training is limited. Despite this, positive effects on the overall education of orthopaedic residents, and on maintaining the proficiency of practicing orthopaedic surgeons, are anticipated.

The extreme range of motion at the shoulder, high velocities and stresses, and repetitive nature of the throwing motion place the throwing athlete at risk for a wide range of pathologic entities. The treating orthopedist must fully understand the biomechanics of the throwing cycle and how it contributes to the potential injuries in the throwing shoulder during each phase of the throwing motion. The goal of orthopedic care and rehabilitation is to allow the throwing athlete to return symptom free to the preinjury level of competition.

The use of bioabsorbable cross-pin transcondylar fixation has remained a viable option for femoral fixation in anterior cruciate ligament reconstruction. Although numerous biomechanical studies have demonstrated high fixation strength and minimal slippage with use of this method of fixation, there have been increasing reports of a variety of clinical complications associated with these implants. We reviewed the literature for all complications associated with the Bio-TransFix implant and present a case report of a patient status after ACL reconstruction using Bio-TransFix cross-pin femoral fixation with iliotibial band friction syndrome from a broken cross-pin four month post-operatively.

The pathology, assessment, and management of articular cartilage lesions of the hip and knee have been the subject of considerable attention in the recent orthopaedic literature. MRI has long been an important tool in the diagnosis and management of articular cartilage pathology, but detecting and interpreting early cartilaginous degeneration with this technology has been difficult. Biochemical-based MRI has been advocated to detect early cartilaginous degenerative changes and assess cartilage repair. Techniques such as T2 mapping, T1rho (ie, T1 in the rotating frame), sodium MRI, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) take advantage of changes in the complex biochemical composition of articular cartilage and may help detect morphologic cartilaginous changes earlier than does conventional MRI. Although the newer modalities have been used primarily in the research setting, their ability to assess the microstructure of articular cartilage may eventually enhance the diagnosis and management of osteoarthritis

Anterior cruciate ligament (ACL) and meniscal injuries are common in both athletes and the general population. Such injuries may lead to early-onset post-traumatic osteoarthritis (OA) in 50% to 60% of patients, regardless of whether patients had reconstruction performed. In younger patients, intra-articular (IA) injection of hyaluronic acid (HA) may be useful for improving short-term outcomes and possibly slowing or arresting the progression of OA. Hyaluronic acid has anti-inflammatory, anabolic, and chondroprotective effects, which have been demonstrated in in vitro and animal models of meniscal and ACL injury. Results from several clinical trials and patient series have demonstrated the benefit of IA HA injection in younger patients with acute knee damage, including symptomatic meniscal tears and isolated ACL injury with chondral injury, although evidence for this is less extensive than the large database supporting the use of IA HA injection in older patients with knee OA. Administration of HA has been shown to improve outcomes in patients undergoing knee arthroscopy, and IA HA also has direct antinociceptive effects that may contribute to its benefit in patients with patellofemoral pain. However, the use of IA HA in patients with ACL injury or early OA has been evaluated in only a few studies. Thus, there is a need for larger-scale randomized controlled trials with longer durations of follow-up to provide more definitive evaluation of the efficacy and safety of IA HA in these patients. Such studies provide an opportunity to further elucidate the benefits of IA HA in younger patients with knee damage and may result in appropriate expansion of use in this large population, which has a substantial need for new treatment alternatives

PURPOSE: We have occasionally observed suture loosening in initial suture legs after final fixation of adjacent suture legs in the lateral row of rotator cuff repairs during arthroscopic rotator cuff repair with transosseous-equivalent suture-bridge constructs. We sought to determine how this occurred and what effects it had on tendon fixation stability. METHODS: Six pairs of fresh-frozen human shoulders were prepared with a simulated cuff defect. A suture-bridge repair was performed in each specimen with one of each pair randomized to one type of 'knotless' lateral-row screw-in anchor and the other of the pair to a knotless push-in type. The repairs were cyclically loaded with 100 N for 1,000 cycles. Suture leg tensions were measured during the repair and after cycling. Lateral tendon laxity was measured before and after cycling. A pilot study on the effect of suture tension on the tendon contact footprint was also performed. RESULTS: The initial suture legs did not show a decrease in tension after the second lateral-row anchor was secured. Tension of the suture legs after cycling showed that no one leg loosened more than another; however, they all loosened when compared with total suture tensions before cycling (0.1 to 1.0 mm, P = .008). There was no significant difference between suture tension changes for the 2 anchor types after cycling (P = .140). Although the lateral tendon laxity increased slightly (0.04 mm) after cycling, this was not significant (P = .245), nor was there a difference between anchor types. CONCLUSIONS: Suture loosening occurred after cycling these rotator cuff repairs, but this did not appear to affect lateral tendon laxity for the 2 lateral anchor types studied, although medial tendon movement was observed. CLINICAL RELEVANCE: Suture loosening after cycling the 2 transosseous-equivalent suture-bridge repairs studied could affect the area and pressure of tendon-bone contact

Anterior glenohumeral instability complicated by bone loss is a challenging problem and, when severe, may require surgical treatment with bone grafting. We review our institution's experience with humeral head and glenoid bone grafting for large Hill-Sachs lesions and glenoid defects. MATERIALS AND METHODS: Patients who underwent intra-articular bone reconstruction for Hill-Sachs and large glenoid defects for anterior instability at our institution during 2002-2008 were retrospectively reviewed. Those who had undergone concomitant humeral head replacement were excluded. Six patients were identified as having undergone allograft or autograft iliac crest bone graft reconstruction of the glenoid, with four available for full follow-up (average 39 months; range, 7 to 63). Five patients were identified as having undergone humeral head allograft reconstruction and four were available for full follow-up (average 28 months; range, 11 to 40). The remaining three patients were available for telephone follow-up. American Shoulder and Elbow Society (ASES) and University of California, Los Angles (UCLA) scores were recorded and radiographs obtained. RESULTS: Average postoperative ASES and UCLA scores for glenoid bone graft patients were 91 and 33, respectively. Average postoperative ASES and UCLA scores for humeral bone graft patients were 85.3 and 28.4, respectively. Glenoid bone graft shoulders, when compared to the opposite normal side, lost an average of 3 degrees of forward flexion, 10 degrees of external rotation, and two levels of internal rotation. Humeral head bone-grafted shoulders, lost an average of 23 degrees of forward flexion, 8 degrees of external rotation, and two levels of internal rotation. No episodes of recurrent subluxation or dislocations were reported. Radiographs showed no evidence of graft resorption or hardware prominence. CONCLUSIONS: Bone grafting procedures around the shoulder for the treatment of instability provided relief from recurrent instability and good functional results