Faculty Bibliography

PURPOSE: The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration. METHODS: Clinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces. RESULTS: In vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications. CONCLUSIONS: Present data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

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

Objectives: The purpose of the present study was to determine when patients recover the ability to safely operate the brakes of an automobile following a right knee anterior cruciate ligament reconstruction (ACLR). Methods: A prospective case series of 27 patients who underwent a right knee ACLR, nine with a bone patellar tendon-bone (BPTB) autograft, nine patients who had hamstring (HS) tendon autograft and nine patients who had tibialis anterior (TA) tendon allograft for their reconstructions were tested in a validated computerized driving simulator. At 7-10 days, three weeks, and six weeks post operatively, patients were evaluated with respect to their brake reaction time (BRT), brake travel time (BTT), and total braking time (TBT). Each cohort was then compared with thirty healthy volunteers with similar demographics to establish normative mean values. Results: At 7-10 days post-operatively, all patients had statistically significant differences compared to controls for BRT, BTT, and TBT, regardless of the graft used for the reconstruction. By three weeks postoperatively, those reconstructed with TA allografts demonstrated a return to normal braking parameters with no statistically significant differences compared to controls between BRT, BTT, and TBT, whereas those with BPTB and HS autografts continued to have significant delays in their BTT and TBT with BPTB (p = 0.007, p = 0.009) and HS (p = 0.016, p = 0.015), respectively. By six weeks post-operatively, braking parameters for patients receiving an ACL reconstruction with a hamstring autograft returned to normal values while those treated with a BPTB autograft continued to demonstrate impairment in brake travel time and total braking time compared to controls; however, their brake reaction time had recovered to normative values. Conclusion: Patients who underwent a right knee ACL reconstruction with a TA allograft regained normal braking times by three weeks post-operatively and continued to improve through the six week postoperative time point. In contrast, those treated with a BPTB or HS autograft demonstrated impaired ability to operate motor vehicle brakes three weeks following surgery. While at six weeks, the braking ability of patients treated with hamstring autografts normalized, those receiving a BPTB autograft continued to demonstrate limitations in their brake travel time and total braking time. Patients should be counseled appropriately when discussing reconstruction options and when it is safe to resume driving

Objectives: The purpose of the current study is to investigate the functional strength outcomes of late distal biceps reconstruction using allograft tissue. Methods: Patients who underwent distal biceps reconstruction with allograft tissue between May 2007 and May 2013 were identified. Charts were retrospectively reviewed for post-operative complications, gross flexion and supination strength, and range of motion (ROM). Isokinetic strength and endurance in elbow flexion and forearm supination were measured in both arms. Tests were conducted using a dynamometer at 60o per second for isokinetic strength and 240o per second for endurance. Isometric strength testing was also measured for elbow flexion and forearm supination. Paired t tests were used for statistical analysis. Results: Ten patients with a mean age of 48 years (range 42 - 61 years) were included in the study. Distal biceps reconstruction was performed using an Achilles tendon allograft in 9 patients and a combination of tibialis anterior allograft and gracilis allograft in 1 patient. Of the reconstructions, 50% involved the dominant arm. Full ROM was observed in all patients at the time of their final follow up assessment. The mean followup for dynamometer strength testing was 34 months (range 13-81 months). No statistical differences were noted between data obtained from operative and contralateral extremities. The average peak torque of the operative limb (38.5+/- 5.9 Nm) was 91.7% of that of the contralateral limb (41.8+/-4.9 Nm) in flexion and 93.4% (operative, 5.7+/-1.3 Nm; contralateral, 6.1+/- 1.0 Nm) in supination. No significant differences were found in fatigue index between operative or contralateral limbs for flexion (operative, 34.1+/-17.1%; contralateral, 30.8+/-17.1%; p = 0.29) or supination (operative, 38.2+/-16.5%; contralateral, 42.1+/-11.9%; p = 0.65). The only complication observed was a transient PIN palsy in one patient which resolved by 3 months post-operatively. All patients reported postoperative cosmetic deformity but found their gross appearance acceptable. Conclusion: Late reconstruction for chronic distal biceps rupture using allograft tissue is a safe and effective solution for symptomatic patients with functional demands in forearm supination and elbow flexion. Dynamometer testing shows near normal return of strength and endurance of both elbow flexion and supination following the procedure

INTRODUCTION: Historically, venous thromboembolism (VTE) in the setting of elective knee arthroscopy has been considered rare. However, more recently, the rate of deep vein thrombosis (DVT) has been reported to be approxi - mately 10%. With increasing recognition of the potential for the development of thromboembolic events, several random - ized trials have evaluated the efficacy of chemoprophylaxis in reducing the risk of VTE following knee arthroscopy. However, all of these studies have evaluated the efficacy of low molecular weight heparins (LMWH), with reductions in the risk of DVT ranging from 65% to 93%, but with the potential side effect of bleeding. At the present time, there have been no randomized studies reported evaluating the utility of aspirin, an agent with a reportedly lower bleeding risk than LMWH, as pharmacologic prophylaxis against VTE after arthroscopic knee surgery. METHODS: In a single-center, randomized, single-blind prospective trial, the efficacy of aspirin as postopera - tive pharmacologic VTE prophylaxis was evaluated in a low risk population undergoing knee arthroscopy. One hundred seventy patients were randomized to a treatment group of 325 mg of aspirin daily for 14 days postoperatively (66 patients) or to the control group with no intervention (104 patients). Bilateral, whole leg, com - pression venous duplex ultrasonography was performed 10 to 14 days postoperatively to document the incidence of DVT. The primary endpoint of the current study was the development of DVT or pulmonary embolism (PE), and the secondary endpoint was the development of a postoperative complication. RESULTS: The study cohort was comprised of 104 males (61%) and 66 females (39%) with a mean age of 44.4 +/- 14.4 years (range: 18 to 75 years). Within both the aspirin treatment and control groups, the surgical procedures in - cluded meniscectomy, ACL reconstruction, chondroplasty, and meniscus repair. No cases of postoperative deep vein thrombosis (DVT) or pulmonary embolism (PE) were identi - fied in either arm of the study during the observation period. Twenty-three patients experienced a complication, including pain or swelling (9%), residual joint line tenderness (3%), arthrofibrosis (0.6%), and instability after a fall (0.6%). Three patients developed knee swelling, two of them in the aspirin group and one of whom required a knee aspiration. However, there was no difference in the development of complications between the two patient populations (p = 0.76, odds ratio [OR] 1.14, 95% confidence interval [CI] 0.5-2.56). CONCLUSIONS: With no cases of VTE identified in our pa - tient population, the use of aspirin in a low-risk population undergoing arthroscopic knee surgery is not warranted.

Preoperative planning is an essential prerequisite for the success of orthopaedic procedures. Traditionally, the exercise has involved the written down, step by step "blueprint" of the surgical procedure. Preoperative planning of the technical aspects of the orthopaedic procedure has been performed on hardcopy radiographs using various methods such as copying the radiographic image on tracing papers to practice the planned inter - ventions. This method has become less practical due to variability in radiographic magnification and increasing implementation of digital imaging systems. Advances in technology along with recognition of the importance of surgical safety protocols resulted in widespread changes in orthopaedic preoperative planning approaches. Nowa - days, perioperative "briefings" have gained particular importance and novel planning methods have started to integrate into orthopaedic practice. These methods include using software that enables surgeons to perform preoperative planning on digital radiographs and to construct 3D digital models or prototypes of various orthopaedic pathologies from a patient's CT scans to practice preoperatively. Evidence-to-date suggests that preoperative planning and briefings are effective means of favorably influencing the outcomes of orthopaedic procedures.

Ice hockey is a fast paced sport with unique injury potential. There are no studies in the literature that examine the shoulder strength and range of motion in this population. Players on a single professional ice hockey team underwent a comprehensive examination of shoulder motion and strength. Shoulder motion and strength between right and left extremities were compared within athletes. Comparisons were made between right and left handed players, players that shoot right versus left handed, and by position. Within individual athletes, there was no difference in motion or strength between right and left shoulders. There was no difference in motion or strength between the dominant and non-dominant shoulder and players that shoot right versus left handed. Defensemen had a statistically significant increase in external rotation with the arm at the side for the left shoulder (66 degrees versus 55 degrees , p = 0.02) and a trend towards increased external rotation with the arm at the side for the right shoulder (65 degrees versus 56 degrees , p = 0.07). In professional ice hockey players, there is no difference in shoulder motion and strength between the right and left upper extremity. Ice hockey defensemen may have more external rotation with the arm at the side than forward.

Achilles tendon pathology is common and affects athletes and nonathletes alike. The cause is multifactorial and controversial, involving biological, anatomical, and mechanical factors. A variety of conditions characterized by Achilles tendon inflammation and/or degeneration can be clinically and histologically differentiated. These include insertional Achilles tendinopathy, retrocalcaneal bursitis, Achilles paratenonitis, Achilles tendinosis, and Achilles paratenonitis with tendinosis. The mainstay of treatment for all of these diagnoses is nonoperative. There is a large body of evidence addressing treatment of acute and chronic Achilles tendon ruptures; however, controversy remains.