Faculty Bibliography

OBJECTIVE. The purpose of this study was to define and correlate the appearance of the rotator cable on MRI with arthroscopy, band-saw cadaveric sections, and histology. MATERIALS AND METHODS. Two cadaveric shoulders underwent 3-T MRI, band-sawing, and histologic evaluation. Three readers evaluated the MRI for the presence of the cable, and the same readers and a pathologist reviewed the macroscopic and microscopic specimens for a structure that corresponded to the cable. Cadaver 1 underwent arthroscopic evaluation to evaluate for the presence of a cable. Seventy consecutive shoulders that underwent 1.5- or 3-T MRI were also reviewed for the presence of the cable and evaluation of its characteristics (location, thickness, and width). RESULTS. A linear band of hypointense signal intensity was found along the undersur-face of the supraspinatus and infraspinatus tendons on both cadaveric MR images, which correlated to a linear band of tissue in the same location on macroscopic and microscopic evaluation and linear thickening along the cuff articular surface on arthroscopy consistent with the cable. The cable was seen in 74.3% of the MRI studies in both sagittal and coronal planes with a mean (+/- SD) distance of the cable from the medial margin of the enthesis of 1.33 +/- 0.27 cm, a mean width of the cable of 1.24 +/- 0.31 cm, and a mean thickness of 0.19 +/- 0.05 cm. CONCLUSION. The rotator cable is a structure that can be consistently seen on gross anatomic and histologic analysis, arthroscopy, and MRI in the intact rotator cuff. Familiarity with the typical location and morphology of the cable may allow easier characterization of disease that can involve the cable, such as rotator cuff tears.

BACKGROUND: Injection to the acromioclavicular (AC) joint can be both diagnostic and therapeutic. PURPOSE: The purpose of this study was to evaluate the accuracy of in vivo AC joint injections. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty patients with pain localized to the AC joint were injected with 1 mL of 1% lidocaine and 0.5 mL of radiographic contrast material (Isovue). Radiographs of the AC joint were taken after the injection. Each radiograph was reviewed by a musculoskeletal radiologist and graded as intra-articular, extra-articular, or partially intra-articular. RESULTS: Of the 30 injections performed, 13 (43.3%) were intra-articular, 7 (23.3%) were partially articular, and 10 (33.3%) were extra-articular. When the intra-articular and the partially articular groups were combined, 20 patients (66.7%) had some contrast dye in the AC joint. CONCLUSION: This study demonstrates that despite the relatively superficial location of the AC joint, the clinical accuracy of AC joint injections remains relatively low.

Background: Allografts offer potential advantages over autografts in anterior cruciate ligament reconstruction (ACLR), including the absence of donor site morbidity, shorter operative times, improved cosmesis, and easier rehabilitation. There is limited and conflicting outcome data for ACLR with tibialis anterior allograft. The purpose of this study was to evaluate the functional outcomes of ACLR with tibialis anterior allograft. Methods:We retrospectively evaluated primary ACL reconstructions using tibialis anterior allograft between January 2004 and December 2006. Clinical outcomes were measured by KT-1000 arthrometry, and International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. Results: 19 patients were available for follow-up at a mean of 2.7 years (range: 2.0 to 3.2). One patient experienced a traumatic re-rupture that required revision and another patient was advised to undergo revision reconstruction for a failed graft. Based on IKDC and Lysholm scoring, 12 patients (63%) had good or excellent results, 4 (21%) patients had fair results, and 3 (16%) patients had poor results. The mean side-to-side difference was 2.7mm (0 to 8.2) and the mean decrease in Tegner activity level was 1.4 (0 to 6). Conclusion:An alarming number of patients demonstrated residual laxity after ACL reconstruction with tibialis anterior allograft. We recommend against using tibialis anterior allograft as a first choice graft for high demand patients.

BACKGROUND: Because current instrumentation makes it possible to perform an arthroscopic transosseous rotator cuff repair, we performed a biomechanical comparison of a double-row transosseous equivalent rotator cuff repair using suture anchors to an arthroscopic, transosseous rotator cuff repair to determine if they provided similar fixation stability. METHODS: Six pairs of shoulders were used. One of each pair had a standard double row, transosseous equivalent arthroscopic rotator cuff repair using a suture-bridge technique with suture anchors, and the other had an arthroscopic transosseous repair using an Xbox technique. The repairs were cycled at 150 N for 10,000 cycles with movement of the lateral cuff edge recorded and then tested to failure. RESULTS: The total cuff edge displacement at 10,000 cycles in the anchor group (transosseous equivalent repair) was 7.9 mm and 6.3 mm for the bone tunnel group (transosseous repair); these were not significantly different (p=0.19). The anchor group failed at an average of 309 N and the bone tunnel group at an average of 339 N (p=0.22). DISCUSSION: Biomechanical testing suggests that arthroscopic, transosseous rotator cuff repair using a Xbox suture configuration is similar in strength and stability to an arthroscopic transosseous equivalent suture-bridge repair. Both techniques demonstrated difficulty in maintaining the lateral position of the tendon.

Objectives: Tenodesis of the long head of the biceps is one of many options to reduce pain caused by proximal long head insertional tendinopathy, tendon instability, or part of a superior labrum anterior-posterior lesion. This technique can be performed either as an open or arthroscopic procedure. The purpose of this study is to compare the relative incidence and demographics of patients who underwent either an arthroscopy or open biceps tenodesis procedure in New York State from 2002-2010. Methods: Retrospective review of patients who underwent open or arthroscopic biceps tenodesis surgery were identified from the New York State Statewide Planning and Research Commission (SPARCS) ambulatory surgery database, which includes all outpatient surgeries performed at hospitals, outpatient surgical centers, and rural clinics in New York State. Cases of open and arthroscopic biceps tenodesis were identified by unique Current Procedural Terminology codes (23430, 29828). Data from 2002 to 2010 were available for open procedures and from 2008 to 2010 for arthroscopic procedures. Chi-square test and student's t-test were used to analyze the data. Variables measured included incidence, age, gender, race, ethnicity, type of operating facility, and primary payor. Results: From 2002 to 2010 the incidence of biceps tenodesis rose over 600%. From 2008 to 2010 there were 2672 open biceps tenodesis procedures and 3289 arthroscopic biceps tenodesis procedures performed in New York State. The arthroscopic group contained significantly more women (33%) than the open group (25%, P<.0001). The average age arthroscopic patients was slightly higher (55.33 years) than that of open patients (54.45 years, P<.01). There was a significantly greater proportion of African- American patients in the arthroscopic group. Patients undergoing arthroscopic surgery were more likely to be treated at a hospital as opposed to a free standing clinic. The most common primary payor for open cases was worker's compensation at 22% of all cases. Of arthroscopic patients, 18% listed worker's compensation as the primary payor. Medicare patients accounted for 16% of open cases and 19% of arthroscopic patients (P<.001). Conclusion: Incidence of biceps tenodesis surgery has increased steadily from 2002 to 2010. There were 23% more arthroscopic procedures performed in 2010 than there were in 2008. Arthroscopic patients are more likely to be older, female, and African American. Arthroscopic biceps tenodeis, which require additional skill and training, were more likely to be performed in a hospital setting

BACKGROUND: Intra-articular glenohumeral (GH) injections are important for diagnostic and therapeutic purposes. It has been suggested that ultrasound guided injections are more accurate than blind or freehand injections. This study assessed the accuracy of ultrasound-guided GH injections compared with freehand injections in fresh cadavers. METHODS: The study used 80 shoulder specimens from fresh cadavers. Ultrasound guidance was used to inject radiopaque contrast in 40 shoulders, and freehand technique was used in the remaining 40. All injections were performed by 2 surgeons (A and B) through a posterior approach. After the injections, radiographs were obtained of the specimens to assess the accuracy of the injections. RESULTS: Sixty-six of 80 (82.5%) injections were accurately administered into the GH joint. Ultrasound-guided injections were accurate in 37 of 40 specimens (92.5%) compared with freehand injections, which were accurate in only 29 of 40 specimens (72.5%; P = .02). Both surgeons independently had higher accuracy using ultrasound-guidance compared with the freehand technique (surgeon A: 90% vs 65%, P = 0.058; surgeon B: 95% vs 80%, P = 0.15). The average time for injections was 52 seconds by the freehand technique and 166 seconds using ultrasound guidance (P < 0.001). CONCLUSIONS: The data from this cadaveric study suggest that ultrasound-guided injections are more accurate at reaching the GH joint than freehand injections. The ultrasound-guided injections took substantially longer to administer. Once familiar with the technique, surgeons can expect improved accuracy and efficacy of GH joint injections using ultrasound guidance in the clinical setting.

OBJECTIVE: The purpose of this study is to assess the accuracy of MRI quantification of glenoid bone loss and to compare the diagnostic accuracy of MRI to CT in the measurement of glenoid bone loss. MATERIALS AND METHODS: MRI, CT, and 3D CT examinations of 18 cadaveric glenoids were obtained after the creation of defects along the anterior and anteroinferior glenoid. The defects were measured by three readers separately and blindly using the circle method. These measurements were compared with measurements made on digital photographic images of the cadaveric glenoids. Paired sample Student t tests were used to compare the imaging modalities. Concordance correlation coefficients were also calculated to measure interobserver agreement. RESULTS: Our data show that MRI could be used to accurately measure glenoid bone loss with a small margin of error (mean, 3.44%; range, 2.06-5.94%) in estimated percentage loss. MRI accuracy was similar to that of both CT and 3D CT for glenoid loss measurements in our study for the readers familiar with the circle method, with 1.3% as the maximum expected difference in accuracy of the percentage bone loss between the different modalities (95% confidence). CONCLUSION: Glenoid bone loss can be accurately measured on MRI using the circle method. The MRI quantification of glenoid bone loss compares favorably to measurements obtained using 3D CT and CT. The accuracy of the measurements correlates with the level of training, and a learning curve is expected before mastering this technique.

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.

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