Faculty Bibliography

BACKGROUND: The purpose of this study was to see if 3-dimensional (3D) magnetic resonance imaging (MRI) could improve our understanding of rotator cuff tendon tear shapes. We believed that 3D MRI would be more accurate than two-dimensional (2D) MRI for classifying tear shapes. METHODS: We performed a retrospective review of MRI studies of patients with arthroscopically proven full-thickness rotator cuff tears. Two orthopedic surgeons reviewed the information for each case, including scope images, and characterized the shape of the cuff tear into crescent, longitudinal, U- or L-shaped longitudinal, and massive type. Two musculoskeletal radiologists reviewed the corresponding MRI studies independently and blind to the arthroscopic findings and characterized the shape on the basis of the tear's retraction and size using 2D MRI. The 3D reconstructions of each cuff tear were reviewed by each radiologist to characterize the shape. Statistical analysis included 95% confidence intervals and intraclass correlation coefficients. RESULTS: The study reviewed 34 patients. The accuracy for differentiating between crescent-shaped, longitudinal, and massive tears using measurements on 2D MRI was 70.6% for reader 1 and 67.6% for reader 2. The accuracy for tear shape characterization into crescent and longitudinal U- or L-shaped using 3D MRI was 97.1% for reader 1 and 82.4% for reader 2. When further characterizing the longitudinal tears as massive or not using 3D MRI, both readers had an accuracy of 76.9% (10 of 13). The overall accuracy of 3D MRI was 82.4% (56 of 68), significantly different (P = .021) from 2D MRI accuracy (64.7%). CONCLUSION: Our study has demonstrated that 3D MR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared with current 2D MRI-based techniques.

Purpose: iBalance high tibial osteotomy, (iHTO, Arthrex Inc, Naples, Florida), is a recently introduced surgical procedure for correction of knee varus malalignment. iHTO, utilizing a polyetheretherketone (PEEK) implant and osteoinductive compounds (OIC), presents challenging post operative radiographs which can easily be misinterpreted as infection. Our purpose is to report, based on review of 24 cases, the previously undescribed to the best of our knowledge, radiographic features of iHTO and its complications. Materials and Methods: Retrospective query of our digital database was performed to identify iHTO cases. The clinical and postsurgical images in all cases with > 1-month follow up imaging were reviewed with attention to 1. Correction of varus malalignment, 2. Healing at the osteotomy site, 3. Changes in the OIC, and 4. Complications. Results: There were 24 iHTOs in 23 patients (17 men, 6 women, ages 21-59, mean 44, median 46), imaged 1 to 29 months post-surgery, with angle of correction, when available, ranging from 5 to 14degree. Immediate post-surgical correction of varus malalignment was seen in 100 % of patients. 100 % depicted oval radiolucencies, at bone PEEK interface simulating erosions and infection. Four, often overlapping, signs of healing were noted: 1. Blurring of bony margins at the osteotomy site, noted within 2 weeks post surgery, 2. Blurring of sharp interface between OIC and host bone, 3. Anterior, posterior and less commonly medial bridging callus, 4. Resorption of OIC, noted as early as 4 months. Complications, seen in 7 cases (29 %), included genu varum recurrence (n = 2), painful exuberant bone formation, (n = 1), and propagation of the osteotomy through the lateral tibial cortex (n = 4). In patients with >6 months follow-up, nonunion and possible infection was seen in 1 patient. 2 patients required total knee arthroplasty due to iHTO failure. Conclusion: iBalance HTO typically depicts oval radiolucencies at the PEEK bone interface not to be mistaken for infection. Familiarity with this features, as well as with other signs of healing, should aid the radiologist in accurate interpretation of post operative films of iHTO patients

Osseous injuries affecting the posterosuperolateral aspect ofthe humeral head, also known as the Hill-Sachs lesion, arecommon and can pose a difficult problem for the operatingsurgeon. Hill-Sachs lesions can lead to recurrent shoulderinstability if not identified and addressed. This review willfocus on osseous defects of the humeral head and addressthe pathoanatomy, diagnosis, indications, and surgicaltechniques for the treatment of these lesions.

Purpose: To see if 3D imaging could improve our understanding of rotator cuff tendon tear shapes on MRI.
Method(s): We performed a retrospective review of 1.5T/3T MR examinations, conducted over an 18-month period, of patients with arthroscopically proven full- thickness rotator cuff tears. Two orthopaedic surgeons reviewed the operative reports/arthroscopic photos for each patient, and characterized, in consensus, the shape of the tear based on a comparison of the tear's width (size) and length (retraction), and involvement of the rotator interval without measurements into the following categories: crescent, longitudinal, U or L-shaped longitudinal, and massive- type. Two musculoskeletal radiologists reviewed the pre-operative MR examination for each patient independently/blind to the arthroscopic findings. Initially, the readers characterized the shape of the tendon tears by reviewing the standard 2DMR sequences and using the same criteria as the surgeons used during their review of the scope images. Next, the readers measured and documented the width and length of each tendon tear using the 2D images. The shape of the tear was then classified based on a previously published MR-based system as either crescent, longitudinal, U or L-shaped, or massive. Four weeks after the initial imaging evaluation, 3DMR reconstructions of each tear were reviewed and the shape documented by each radiologist independently/blind to the arthroscopic results using the same system used by our orthopaedic colleagues. These results were then compared to the 2D imaging evaluations and arthroscopic findings. Statistical analysis included 95% confidence intervals, McNemar test, and intra-class correlation coefficients.
Result(s): A total of 34 patients were included in the study; 21 had crescent shaped tears and 13 had longitudinal tears during arthroscopy. Of the 13 longitudinal tears, 8 were subtyped as U-shaped, while 5 were described as L-shaped. 6 of the 13 longitudinal tears were additionally classified as massive-type. There was no significant difference when comparing the accuracy of the tear shape characterizations made on 2DMR imaging without measurements (pre) and with measurements (post). The accuracy for differentiating between crescent shaped, longitudinal, and massive tears was the same for reader 1, 70.6% (24/34; p=1) and more accurate using the post 2D data for reader 2 (67.6%(post) vs. 61.8%(pre), p=0.5). The accuracy for tear shape characterization between crescent and longitudinal using the 3D reconstructions for reader #1 was 97.1%(33/34) and 88.2% (30/34) for reader #2. When this characterization included subclassifying the longitudinal tears into U or-L shaped, the accuracy for reader #1 was 97.1% and 82.4% for reader #2. When further characterizing the longitudinal tears as massive or not, both readers had an accuracy of 76.9% (10/13). The overall accuracy of the 3D reconstructions was 82.4% (56/68), significantly different (p=0.021) from the post 2D accuracy (64.7%) and pre 2D accuracy (60.3%, p=0.001). The intraclass correlation coefficient for the 2D measurements of width and length were 0.81, moderate agreement, for width and 0.95, strong agreement, for length.
Conclusion(s): Our study has demonstrated that 3DMR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared to the current 2DMR imaging based techniques

PURPOSE: The long head of the biceps can develop tendonitis and tendinosis, which can lead to pain in the bicipital groove. The use of bicortical button fixation allows for a smaller defect in the humerus compared with tenodesis screws, reducing the risk of fracture. Our objective is to evaluate the exit location of our bicortical button and its relation to relevant posterior nervous structures. METHODS: We performed anatomic dissection of 6 fresh-frozen cadaveric upper extremities. At the level of the inferior border of the pectoralis major tendon, the musculotendinous junction of the long head of the biceps was identified. At the base of the bicipital groove, a 3.2-mm guidewire was advanced perpendicularly through both the anterior and posterior cortex. Posteriorly, the radial and axillary nerves were carefully dissected. For each dissection, we recorded the closest distance from the posterior cortical hole created by our drill to both the axillary and radial nerves using digital calipers. RESULTS: The mean distance from the axillary nerve to the posterior drill hole was 25.1 mm (95% confidence interval, 21.6 to 28.6 mm). The mean distance from the radial nerve to the posterior drill hole was 30.3 mm (95% confidence interval, 27.2 to 33.4 mm). CONCLUSIONS: With placement of the tenodesis at the inferior aspect of the bicipital groove in conjunction with the musculotendinous junction, open subpectoral tenodesis of the long head of the biceps can be performed using bicortical button fixation without risk to the posterior nervous structures. CLINICAL RELEVANCE: This cadaveric study suggests that posterior proximal humerus nervous structures can be avoided with proper tenodesis placement.

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.

OBJECTIVE: To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. MATERIALS AND METHODS: Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. RESULTS: There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. CONCLUSIONS: 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss.

PURPOSE: The purpose of this study was to determine the incidence of venous thromboembolism (VTE) after hip arthroscopy. METHODS: Over the course of 13 months, four surgeons that routinely perform hip arthroscopy participated in a protocol to screen all patients postoperatively for deep venous thrombosis (DVT) using bilateral venous duplex ultrasound at or about the 2 week postoperative time point. All patients were assessed and stratified for VTE risk prior to surgery. Mechanical intraoperative and postoperative chemoprophylaxis were not administered. Perioperative factors, such as weightbearing status after surgery, traction time, and anesthesia type, were recorded. RESULTS: We identified 139 eligible patients (average age 37.7, SD = 12.0) that underwent hip arthroscopy. The incidence of symptomatic VTE was 1.4 percent (2/139). Of the entire patient pool, 81 obtained a follow-up ultrasound. There were no cases of asymptomatic deep vein thrombosis (DVT). There were two symptomatic venous thromboembolic events noted; one DVT and one pulmonary embolus. One patient had no risk factors; the other was overweight and routinely took oral contraceptives. Amongst the patient co- hort, the mean BMI was 25.9 (SD = 4.8). The mean traction time was 58.9 minutes (SD = 23.1). Most patients (71%) were partial weightbearing after the procedure. CONCLUSION AND CLINICAL RELEVANCE: In patients under- going hip arthroscopy, the rate of postoperative VTE was low, despite the use of prolonged axial traction and surgi- cal proximity to the pelvic veins. Although patients should be counseled preoperatively regarding the risk of VTE, we believe that routine use of pharmacologic prophylaxis is not indicated following hip arthroscopy if patients are properly risk stratified prior to surgery and found to be at low risk for VTE.

Bone and tissue adhesives are common and beneficial supplements to standard methods of musculoskeletal tissue suture repair. Knowledge and development of biologically derived or inspired adhesives useful in orthopedic surgery are rapidly advancing. Recent literature demonstrates the increased adjunct or primary use of biological adhesives in the repair of musculoskeletal soft tissues, chondral fractures, and osteochondral fractures. Adhesives offer more benefits and enhancements to tissue healing than current fixation methods afford, including improved biocompatibility, resorbability, and nonimmunogenicity. Further investigation is required to determine the extent of the role that these bioadhesives can play in orthopedic surgery. The largest group of biologically derived adhesives and sealants is fibrin sealants, which include first- and second-generation commercially available fibrin sealants, autologous fibrin sealants, and variants. Other groups include gelatin-resorcin aldehydes, protein-aldehyde systems, collagen-based adhesives, polysaccharide-based adhesives, mussel adhesive proteins, and various biologically inspired or biomimetic glues. Potential uses include applications in orthopedic-related blood conservation, arthroplasty, articular cartilage disorders, sports medicine, spine surgery, trauma, and tumors. The development of an adhesive with universal application is likely unfeasible, given the unique characteristics of various musculoskeletal tissues. However, the literature demonstrates the overall underuse of adhesives and indicates the rising probability of the development of a successful variety of bioadhesives for use in orthopedic surgery. C1 [Shah, Neil V.; Meislin, Robert] NYU, Hosp Joint Dis, Dept Orthopaed Surg, New York, NY 10016 USA

Bone and tissue adhesives are common and beneficial supplements to standard methods of musculoskeletal tissue suture repair. Knowledge and development of biologically derived or inspired adhesives useful in orthopedic surgery are rapidly advancing. Recent literature demonstrates the increased adjunct or primary use of biological adhesives in the repair of musculoskeletal soft tissues, chondral fractures, and osteochondral fractures. Adhesives offer more benefits and enhancements to tissue healing than current fixation methods afford, including improved biocompatibility, resorbability, and non-immunogenicity. Further investigation is required to determine the extent of the role that these bioadhesives can play in orthopedic surgery. The largest group of biologically derived adhesives and sealants is fibrin sealants, which include first- and second-generation commercially available fibrin sealants, autologous fibrin sealants, and variants. Other groups include gelatin-resorcin aldehydes, protein-aldehyde systems, collagen-based adhesives, polysaccharide- based adhesives, mussel adhesive proteins, and various biologically inspired or biomimetic glues. Potential uses include applications in orthopedic-related blood conservation, arthroplasty, articular cartilage disorders, sports medicine, spine surgery, trauma, and tumors. The development of an adhesive with universal application is likely unfeasible, given the unique characteristics of various musculoskeletal tissues. However, the literature demonstrates the overall underuse of adhesives and indicates the rising probability of the development of a successful variety of bioadhesives for use in orthopedic surgery. As a result of reading this article, physicians should be able to: 1. Describe the difference between adhesives and sealants. 2. Recognize fibrin adhesives commonly used in practice today and identify other biological adhesives with rising potential. 3. Analyze how fibrin sealants work relative to fibrin and fibrinogen. 4. Identify anatomical areas and techniques in which fibrin sealants are used.