This study shows that lateral meniscal root injury further destabilizes the ACL-deficient knee and thus advances the concept that the lateral meniscus is a secondary stabilizer of the knee under pivot-shift loading. In the absence of stronger evidence, the study data suggest a rationale for surgical repair of lateral meniscal root tears encountered in the setting of ACL tears.

Background: The benefits of platelet-rich plasma (PRP) are believed to be in part dependent on growth factor release after platelet activation. Platelet activation is complex and involves multiple mechanisms. One important mechanism is driven by cyclooxygenase 1 (COX-1)–mediated conversion of arachidonic acid (AA) to precursor prostaglandins that then mediate proinflammatory responses that trigger growth factor release. Acetylsalicylic acid (ASA; also known as aspirin) is known to irreversibly inhibit COX-1, thereby blocking AA-mediated signaling; however, it is unclear whether ASA use alters growth factor release from freshly isolated PRP. Purpose: To assess the effects of low-dose ASA use on activation of growth factor release from freshly isolated human PRP via AA and thrombin (TBN). Study Design: Controlled laboratory study. Methods: Twelve healthy men underwent blood collection and leukocyte-rich PRP (LR-PRP) preparation through a double-spin protocol to obtain baseline whole blood and PRP counts the same day. PRP was aliquoted into 3 groups: nonactivated, AA activated, and TBN activated. Immediately after activation, the concentrations of transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor AB (PDGF-AB) were measured using enzyme-linked immunosorbent assays (ELISAs). The same 12 participants were then placed on an 81-mg daily dose of oral ASA for 14 days. Repeat characterization of whole blood and PRP analyses was done on day 14, followed by repeat ELISAs of growth factors under the same nonactivated and activated settings as previously stated. Results: Fourteen days of daily ASA had no effect on the number of platelets and leukocytes measured in whole blood and LR-PRP. Compared with nonactivated LR-PRP, AA- and TBN-mediated activation led to significant release of VEGF and PDGF-AB. In contrast, release of TGF-β1 from LR-PRP was observed only with activation by AA, not with TBN. Consistent with its inhibitory role in AA signaling, ASA significantly inhibited AA-mediated release of all 3 growth factors measured in this study. Although ASA had no effect on TBN-mediated release of VEGF and TGF-β1 from LR-PRP, ASA did partially block TBN-mediated release of PDGF-AB, although the mechanism remains unclear. Conclusion: Daily use of low-dose ASA reduces VEGF, PDGF-AB, and TGF-β1 expression in freshly isolated human LR-PRP when activated with AA. Clinical Relevance: Reduction in growth factor release attributed to daily use of low-dose ASA or other COX inhibitors can be mitigated when PRP samples are activated with TBN. Clinical studies are needed to determine whether activation before PRP injection is needed in all applications where ASA is in use and to what extent ASA may inhibit growth factor release in vivo at the site of injury.

The menisci play an important biomechanical role in axial load distribution of the knees by means of hoop strength, which is contingent on intact circumferentially oriented collagen fibers and meniscal root attachments. Disruption of the meniscal root attachments leads to altered biomechanics, resulting in progressive cartilage loss, osteoarthritis, and subchondral edema, with the potential for development of a subchondral insufficiency fracture. Identification of meniscal root tears at magnetic resonance (MR) imaging is crucial because new arthroscopic surgical techniques (transtibial pullout repair) have been developed to repair meniscal root tears and preserve the tibiofemoral cartilage of the knee. An MR imaging classification of posterior medial meniscal root ligament lesions has been recently described that is dedicated to the posterior root of the medial meniscus. An arthroscopic classification of meniscal root tears has been described that can be applied to the anterior and posterior roots of both the medial meniscus and the lateral meniscus. This arthroscopic classification includes type 1, partial stable root tears; type 2, complete radial root tears; type 3, vertical longitudinal bucket-handle tears; type 4, complex oblique tears; and type 5, bone avulsion fractures of the root attachments. Knowledge of these classifications and the potential contraindications to meniscal root repair can aid the radiologist in the preoperative reporting of meniscal root tear types and the evaluation of the tibiofemoral cartilage. As more patients undergo arthroscopic repair of meniscal root tears, familiarity with the surgical technique and the postoperative radiographic and MR imaging appearance is important to adequately report the imaging findings. RSNA, 2016.

Background:Virtual reality arthroscopic simulators are an attractive option for resident training and are increasingly used across training programs. However, no study has analyzed the utility of simulators for trainees based on their level of training/postgraduate year (PGY).Purpose/Hypothesis:The primary aim of this study was to determine the utility of the ArthroS arthroscopic simulator for orthopaedic trainees based on their level of training. We hypothesized that residents at all levels would show similar improvements in performance after completion of the training modules.Study Design:Descriptive laboratory study.Methods:Eighteen orthopaedic surgery residents performed diagnostic knee and shoulder tasks on the ArthroS simulator. Participants completed a series of training modules and then repeated the diagnostic tasks. Correlation coefficients (r2) were calculated for improvements in the mean composite score (based on the Imperial Global Arthroscopy Rating Scale [IGARS]) as a function of PGY.Results:The mean improvement in the composite score for participants as a whole was 11.2 ± 10.0 points (P = .0003) for the knee simulator and 14.9 ± 10.9 points (P = .0352) for the shoulder simulator. When broken down by PGY, all groups showed improvement, with greater improvements seen for junior-level residents in the knee simulator and greater improvements seen for senior-level residents in the shoulder simulator. Analysis of variance for the score improvement variable among the different PGY groups yielded an f value of 1.640 (P = .2258) for the knee simulator data and an f value of 0.2292 (P = .917) for the shoulder simulator data. The correlation coefficient (r2) was –0.866 for the knee score improvement and 0.887 for the shoulder score improvement.Conclusion:Residents training on a virtual arthroscopic simulator made significant improvements in both knee and shoulder arthroscopic surgery skills.Clinical Relevance:The current study adds to mounting evidence supporting virtual arthroscopic simulator–based training for orthopaedic residents. Most significantly, this study also provides a baseline for evidence-based targeted use of arthroscopic simulators based on resident training level.

Purpose To quantify social media use of professional sports team physicians on popular platforms and analyze differences between users and nonusers. Methods Team physicians for professional sports teams in the National Football League, National Hockey League, Major League Baseball, and National Basketball Association were identified and characterized based on training background, practice setting, and geographic location. Rates of social media presence on Facebook, Twitter, LinkedIn, Instagram, and ResearchGate were determined. Differences between social media users and nonusers were analyzed. Results In total, 505 professional team physicians were identified across 4 major professional sports; 64.6% of physicians were orthopaedic surgeons. Of 505 physicians, 65.7% had a social media presence. More specifically, 21.8% had a professional Facebook page, 22.6% a professional Twitter page, 52.1% a LinkedIn profile, 21.4% a ResearchGate profile, and 9.1% an Instagram account. Fellowship-trained physicians ( P = .008) had greater odds of having a social media presence. Conclusions Nearly two-thirds of professional team physicians have a social media presence, most commonly LinkedIn. Fellowship training is a significant predictor of sports medicine physician social media presence. Sports league affiliation, training background, practice setting, and geographic location are unrelated to social media presence. Level of Evidence IV, cross-sectional study.