Camp, Christopher L.

Objectives: There is a paucity of literature regarding outcomes of anterior shoulder instability (ASI) in throwers and overhead athletes (OHA). The purpose of this study was to report the pathology, treatment strategies, and outcomes of ASI in throwers and overhead athletes utilizing an established US geographic population-based cohort. Methods: An established geographic database of more than 500,000 patients was used to identify athletes <40 years of age with ASI between 1994 and 2016. Medical records were reviewed to obtain demographics, type of sport, surgical details, and clinical outcomes. Patients were contacted after final clinical follow-up for patient reported outcomes (PRO). The Western Ontario Shoulder Instability (WOSI) score, return to sport at previous level of performance (RPP), rate of return to play (RTP) and time to RTP were recorded. Statistical analysis was performed comparing throwers to non-throwers and OHA to non-overhead athletes (NOHA). Results: The study population consisted of 171 patients, 114 NOHA and 57 OHA. Of the OHA, 40 were throwers. The mean follow-up was 14.7 ± 5.6 years for PRO’s and 11.7 ± 7.3 years for last clinical evaluation. No difference in overall instability events was seen in either group. Throwers were more likely to present with subluxations while non-throwers were more likely to present with frank dislocations. NOHA and non-throwers were more likely than OHA and throwers to have a history of trauma related to ASI, respectively ( P = <.001, P = .002). Throwers were more likely to undergo an open surgical procedure (45%) than non-throwers (15%) ( P = .038). The rate of recurrent instability between groups was similar. Throwers returned to sport at a lower rate than non-throwers, however this did not reach significance (64% vs 83%, P = .100). Throwers and OHA reported similar WOSI scores, RPP and time to RTP grouped by surgical or conservative management compared to non-throwers and NOHA, respectively. Conclusions: In a US cohort of patients, throwers and OHA had a similar number of instability events compared to non-throwers and NOHA, respectively. Non-throwers and NOHA were more likely to present with frank dislocation which is supported by the significantly higher rates of trauma in both groups. Notably, the WOSI score, RPP, rate of RTP and time to RTP showed no difference between throwers and OHA when compared to their non-throwing and NOHA counterparts.

Background: Meniscal tears are common in active patients, but treatment trends and surgical outcomes in young patients with lateral meniscal tears are lacking. Purpose: To evaluate treatment trends, outcomes, and failure rates in young patients with lateral meniscal tears. Study Design: Cohort study; Level of evidence, 3. Methods: Patients aged ≤25 years treated surgically for isolated lateral meniscal tears from 2001 to 2017 were identified. Treatment trends were compared over time. International Knee Documentation Committee (IKDC) scores and failure rates were compared by treatment modality (meniscectomy vs meniscal repair). Failure was defined as reoperation, symptomatic osteoarthritis, or a severely abnormal IKDC score. Univariate regression analyses were performed to predict failure and IKDC scores based on treatment, type and location of tear, or extent of meniscectomy. Results: Included were 217 patients (226 knees) with a mean age of 17.4 years (range, 7-25 years); of these patients, 144 knees (64%) were treated with meniscectomy and 82 knees (36%) with meniscal repair. Treatment with repair increased over time compared with meniscectomy ( P < .001). At a minimum 2-year follow-up (mean, 6.1 ± 3.9 years), 107 patients (110 knees) had IKDC scores, and analysis indicated that although scores in both groups improved from pre- to postoperatively (repair: from 69.5 ± 13.3 to 97.4 ± 4.3; meniscectomy: from 75.7 ± 9.0 to 97.3 ± 3.9; P < .001 for both), improvement in IKDC score was greater after repair (27.9 ± 13.9) versus meniscectomy (21.6 ± 9.4) ( P = .005). Included in the failure analysis were 184 patients (192 knees) at a mean follow-up of 8.4 ± 4.4 years. The rates of reoperation, symptomatic osteoarthritis, and failure were not significantly different between the meniscectomy and repair groups. Conclusion: An increase was seen in the rate of isolated lateral meniscal tear repair in young patients. IKDC score improvement was greater after repair than meniscectomy, although postoperative IKDC scores were similar. Symptomatic arthritis, reoperation, and failure rates were similar between groups; however, there was a trend for increased arthritis symptoms in patients treated with meniscectomy, especially total meniscectomy. Treatment modality, type and location of tear, and amount of meniscus removed were not predictive of final IKDC scores or failure.

Background: Osteochondritis dissecans (OCD) of the capitellum is common in throwing athletes and is believed to result from repetitive overloading on the radiocapitellar (RC) joint, although the cause and mechanism remain unclear. The torsional forces (moments) generated by the triceps during elbow extension pull only on the ulna; therefore, the radial head moves passively across the capitellum and is effectively “dragged along” by the ulna. Any laxity in the proximal radioulnar joint could lead to asynchronous motion between the radius and ulna, resulting in the radial head lagging behind the coronoid and possibly malarticulating with the capitellum during such motion. Hypothesis: Radial head motion on the capitellum lags behind ulnohumeral joint motion during simulated throwing. Study Design: Controlled laboratory study. Methods: A total of 8 cadaveric elbows were tested under simulated throwing, including active extension of the elbow generated by pulling of the triceps under valgus stress, as well as during passive extension under valgus stress to serve as a reference. Ulnohumeral motion was tracked using a video camera. Radial head motion was tracked using an intra-articular, thin-film pressure sensor mounted on the capitellum, and the longitudinal movement of the center of force (COF) of the radial head was measured. Radial head motion was compared between passive and active motion for each 10° of elbow extension from 90° to 20°. Results: Elbow motion during simulated active extension reached an angular velocity of 366 deg/s. Radial head motion during simulated active extension significantly lagged compared with its motion during passive extension at every elbow extension angle examined between 70° and 20° ( P < .001). The maximal lag reached a mean of 4 mm (range, 2-7 mm). In other words, RC and ulnohumeral motion were asynchronous during simulated throwing. Conclusion: This study describes a novel phenomenon: motion of the radial head across the capitellum during rapid extension, such as in baseball pitching, lags behind that seen during passive elbow motion. According to a new proposed theory of OCD lesion development, this lag should result in RC incongruency and elevated shear forces on the capitellum due to edge loading. Clinical Relevance: We propose a new biomechanical explanation for OCD of the capitellum in baseball pitchers: radial head lag. Understanding this process is the first step in efforts to prevent this common injury.

Background: In recent years, the prevalence of medial ulnar collateral ligament injuries has increased in throwers of all ages and skill levels. The motusBASEBALL sensor possesses an inertial measurement unit (IMU) that has been developed and applied to the throwing arm to allow for measurements of several objective parameters, which may prove beneficial for monitoring, rehabilitation, and injury prevention in the throwing athlete. However, the reliability, consistency, and validity of the IMU have not been independently assessed. Purpose: To evaluate the reliability, consistency, and validity of the motusBASEBALL sensor compared with the historic gold standard of marker-based motion capture. Study Design: Controlled laboratory study. Methods: A total of 10 healthy male baseball athletes with varsity-level high school experience volunteered to participate in this study. Participants were fitted with 37 retroreflective markers for motion capture and the motusBASEBALL IMU sensor. Participants threw 5 fastballs at maximum effort, with measurements recorded simultaneously by motion capture and the IMU. Arm slot, arm speed, arm stress, and shoulder rotation were measured and compared. Results: Of the 4 metrics generated by the IMU, significant differences were found for 3 of the throwing metrics compared with motion capture including arm slot (5.0°± 6.1°; P = .037), elbow varus torque (9.4 ± 12.0 N·m; P = .037), and shoulder rotation (6.3°± 6.1°; P = .014). Arm speed did not demonstrate a statistically significant difference (29.2 ± 96.8 rpm; P = .375). The IMU consistently underreported pitching performance values. Shoulder rotation exhibited excellent reliability with <5° of error, and arm slot demonstrated good reliability with <10° of error. Arm stress and arm speed were less reliable. Conclusion: The IMU was not accurate or valid for arm slot, arm stress, and shoulder rotation compared with marker-based motion capture. It was relatively accurate for arm speed. Despite its lack of validity, it was consistent and reliable for arm speed and shoulder rotation and relatively reliable for arm slot and arm stress. Caution should be used when comparing values provided by this IMU to the gold standard of marker-based motion capture. Clinical Relevance: IMU technology has potential to be used in monitoring, rehabilitation, and injury prevention in throwing athletes if valid. This study demonstrates that the values provided by the IMU should not be considered equivalent to those generated by the gold standard of marker-based motion capture; however, there may still be a role for this technology when relying on its internal consistency for intrathrower comparisons and tracking.

Objectives: Meniscus root tears are increasingly being recognized. Meniscus extrusion has previously been associated with medial root tears; however, the relationship between secondary meniscus restraints, such as the meniscotibial (MT) ligament, extrusion, and root tears has yet to be formally evaluated. The purpose of this study was to better understand the association between MT ligament competence, medial meniscus extrusion, and medial meniscus posterior root tears (MMPRT), as well as to determine the progression of meniscus extrusion over time. Methods: Serial MRI’s from our institution were reviewed for patients who showed evidence of medial meniscus extrusion and MMPRT on at least one of 2+ available MRI’s. All patients were symptomatic at the time of diagnosis. All MRI’s were analyzed independently by two board-certified musculoskeletal radiologists. MT ligament disruption, medial meniscus extrusion, and MMPRT presence was recorded for each MRI. The time between MRI’s, presence of insufficiency fractures, and Outerbridge classification for the medial femur and tibia were also evaluated. Results: 27 knees in 26 patients were included in this study, with a total of 63 MRI’s analyzed (21 knees with 2 MRI’s, 3 with 3 MRI’s, and 3 with 4 MRI’s). All patients demonstrated clear medial meniscus extrusion and meniscotibial ligament disruption prior to the subsequent development of MMPRTs (p < 0.001). Mean extrusion at the time of initial MRI was 3.3 ± 1.1 mm, and increased significantly to 5.5 ± 1.8 mm at the time of first imaging with an identified MMPRT (p < 0.001). The average time between initial MRI and the first identification of MMPRT on a later MRI was 1.7 ± 1.6 years. Conclusions: In a sample of 27 symptomatic knees with serial MRI’s both before and after MMPRT diagnosis, all patients demonstrated MT ligament disruption and associated meniscus extrusion prior to the development of subsequent medial meniscus root tears. These findings suggest that MT ligament disruption and medial meniscus extrusion represent early and predisposing events contributing to MMPRT. Therefore, this provides a possible explanation of why meniscus extrusion is not corrected with medial meniscus root repair.

Professionalism is a core competency of gross anatomy and general medical school curricula requiring students to develop the skills of giving and receiving peer feedback. Our study evaluated the effectiveness of delivering feedback in a group setting compared to delivering it individually. The first year class of Mayo medical students (n=50) enrolled in gross anatomy (in dissection teams of 3 or 4) completed weekly anonymous peer‐evaluations of their team regarding multiple aspects of professionalism (integrity, responsibility, compassion, and peer respect). Professionalism scores were calculated using the quantitative values from these surveys. Students were also asked to comment on strengths and areas for improvement for each student. At the mid‐point of the course, peer comments and professionalism scores were shared with students in debriefing sessions, either individually or as a team. Preliminary analysis of pre‐ and post‐intervention professionalism scores indicates that students receiving feedback in a group setting are more likely to demonstrate higher scores on subsequent evaluations. Our findings suggest that providing feedback to first‐year medical students in a group setting is more beneficial for group dynamics and may improve professional attitudes and behaviors. This work was supported by the Mayo Clinic Department of Anatomy. Grant Funding Source None

Gross anatomy courses often utilize teaching assistants (TAs) to serve a multifaceted purpose. Qualitative analysis of interviews with gross anatomy TAs reveals seven distinct roles: formal teaching during course lectures, informal teaching during dissection, prosecting a demonstration cadaver, orchestrating regular review sessions, coordinating formative feedback about academic progress and professionalism, tutoring struggling students outside of class time, and supporting students in crisis should the need arise. Analysis also finds that TAs did not anticipate the full scope of their duties prior to undertaking them, and felt particularly unprepared to address issues of student mental health. We report our findings and propose a model for proactively training TAs for their inherently complex role. This work was supported by the Mayo Clinic Department of Anatomy. Grant Funding Source Student/Postdoctoral Travel Award Student Award

Early medical education courses provide opportunities for promoting leadership in future physicians. Our research sought to integrate explicit activities of teamwork and leadership into the first‐year gross anatomy course and assess student leaders through self reflection and team evaluation. Fifty first‐year medical students were assigned to three‐ or four‐member dissection teams with group leaders designated on a rotating basis. Teamwork was emphasized through daily group quizzes, oral patient presentations relating clinical diagnoses to anatomy, and extensive embryology presentations. Group leaders were responsible for leading the dissections after attending daily orientation sessions on the teaching cadaver. Team and self evaluations of group leaders were gathered with weekly electronic surveys. Preliminary results suggest that team leaders rate themselves lower than their teammates do with respect to altruism, accountability and responsibility. One explanation for this discrepancy is decreased self‐awareness of student leaders regarding their own performance. Further research may demonstrate whether increased communication between leaders and team members can improve leaders' awareness of their capabilities. Research support came from the Mayo Clinic Department of Anatomy. Grant Funding Source N/A

Recent curricular redesign at Mayo Medical School integrated radiology into first‐year gross and developmental anatomy. The resulting six‐week (120 contact hours) Human Structure block teaches gross anatomy through dissection, radiologic imaging, and correlation with embryology. To further promote holistic physician‐development, refinement of the Human Structure course has been driven by the six core competencies of the Accreditation Council for Graduate Medical Education (ACGME): patient care, medical knowledge, practice‐based learning, interpersonal skills, professionalism, and systems‐based practice. We report here more than 20 educational interventions built into the Human Structure block that may serve as a model for incorporating the ACGME core competencies into early medical education. The block emphasizes clinically oriented anatomy, invites self‐ and peer‐evaluation, provides daily formative feedback through an audience response system, and employs team‐based learning. The course curriculum includes didactic briefing sessions and roles for students as teachers, leaders, and collaborators. Third‐year medical students serve as teaching assistants, enhancing their own knowledge of anatomy, bettering their skills as medical educators, and facilitating group communication and critiques. This work was supported by the Mayo Clinic Department of Anatomy. Grant Funding Source None

Background: With the expanding use of reverse shoulder arthroplasty (RSA) to treat various shoulder conditions, there has been a rise in the number of RSAs performed, especially in physically active patients. Limited information regarding sports after RSA is available to properly counsel patients on postoperative expectations. Purpose: To assess the rate of return to sports as well as the ability to return to the same level of preoperative intensity, frequency, and duration of sport after primary RSA. Study Design: Case series; Level of evidence, 4. Methods: This was a retrospective review of patients who underwent primary RSA at our institution between 2014 and 2016. Shoulder motion, Subjective Shoulder Value score, American Shoulder and Elbow Surgeons score, pre- and postoperative sports activities, and barriers to return to sport were assessed in 109 patients after RSA (93 patients with unilateral RSA and 16 patients with bilateral RSA). The mean age at the time of surgery was 70 years (range, 34-86 years), with a mean follow-up of 3.9 years (range, 2-12 years). Results: The mean rate of return to sports was 70.1% (range, 0%-100%). There was no difference in return to sports between those with uni- and bilateral RSA ( P = .64). Fishing, swimming, elliptical/treadmill, and hunting were the most common sports after RSA with return rates of 91%, 73%, 86%, and 82% respectively. A majority of patients returned to the same level of preoperative intensity, frequency, and duration for all sports except for climbing and swimming. There was a lower mean rate of return for high-demand sports (62.9%) compared with low- and medium-demand sports (76.7%) ( P = .005). The most common reasons for inability to return to sports included limited motion, fear of injury, and weakness. Conclusion: Patients who had undergone primary uni- or bilateral RSA reported a 70.1% rate of return to sports with maintenance of the same level of intensity, duration, and frequency of preoperative sport participation. Rates of return to high-demand sports were lower than low- and medium-demand sports. Patients also had difficulty returning to overhead sports.