Search

Background: It is unknown how different pitch count limits and rest day requirements affect cumulative pitch counts during a baseball season. Purpose: To determine (1) the variability of pitch count rules in high school baseball and (2) the theoretical effect of different pitch count limits and rest day combinations on game, weekly, and seasonal pitch totals in high school baseball pitchers. Study Design: Cross-sectional study. Methods: Pitch count rules for the 2019-2020 academic year for 48 sanctioned states were recorded from each state’s athletic association website. Maximum pitch count limits were recorded along with the number of pitches allowed before requiring 0 to 5 rest days before the next pitching outing. Rules were also analyzed for several distinctions, including the athlete’s level of competition, age, and grade. To determine the effect of pitch count rules and rest days, a theoretical 3-month season was calculated in the following scenarios: (1) variable maximum pitch count limits with a universal 3-day rest requirement, (2) universal 110 pitch count limit with variable rest day requirements (3, 4, or 5 days), and (3) actual pitch count limits and required rest days for every state assuming pitchers throw as many pitches as allowed. Analysis of variance and Student t tests were used to compare between-group and intragroup seasonal pitch totals based on variations in required rest days. Results: The most common maximum pitch count limit for a varsity high school athlete was 110 pitches (range, 100-125 pitches) with 4 rest days (range, 0-5 days). We found that 23 states (48%) did not make distinctions for pitch count rules based on the athlete’s level of competition, age, or grade. We noted a 25% increase in total seasonal pitch counts between the smallest and largest pitch count limit when assuming constant 3-day rest. We found a 53% difference in total seasonal pitch count when rest days varied between 3 and 5 days with a constant 110-pitch limit. Allowing 140 pitches in a 4-day span without a specific rest day requirement resulted in the highest seasonal pitch count (Nevada). There was a 49% difference in maximum seasonal pitch counts between the most and least restrictive states ( P < .001). Submaximum pitch limits resulted in higher seasonal pitch counts than maximum pitch limits in 56% of states. Conclusion: Pitch count rules vary widely by state. Required rest days influenced total seasonal pitch counts more than maximum or submaximum pitch count limits.

Background: Professional baseball pitchers sustain 75% of knee injuries while at the pitcher’s mound, yet no pitching motion has been associated directly with such injuries. Stride width is a potential, modifiable risk factor worth investigating. Hypothesis: Increased stride width in both the positive and negative directions (deviations from neutral stride width) would correlate with increased incidence of knee injury in pitchers. Study Design: Descriptive laboratory. Level of Evidence: Level 5. Methods: Professional pitchers (n = 199) were evaluated with motion capture (480 Hz) while pitching. Injury history over 10 years was recorded at face-to-face interviews with pitchers. Players were subsequently grouped into stride width tertiles, compared for previous injury incidence of the lower extremities. Regressions were performed to observe performance benefits of stride width with ball velocity, accuracy, or consistency in pitch location as secondary outcomes. Results: Of the 40 lower extremity injuries reported, meniscal injury (27.5%) was the most common, followed by foot stress fracture (20.0%). Significant differences in injury incidence were noted between the least and most positive stride width tertiles: lower extremity (10.4% vs 25.8%, respectively; P = 0.03), knee (3.0% vs 15.2%, respectively; P = 0.02), and meniscal (0.0% vs 12.1%; P = 0.00). Stride width of pitchers with meniscal injury in the lead (32.6 ± 7.1 cm, n = 5; P = 0.02) and stance leg (33.5 ± 10.6 cm, n = 5; P = 0.03) was significantly more positive than that of uninjured pitchers (21.1 ± 11.5 cm, n = 164). No significant relationships were established between stride width and ball velocity ( P = 0.54) or pitch location metrics ( P > 0.05). Conclusion: Pitchers with increased positive, stride width had significantly higher incidence of lower extremity injury (knee and meniscus). Wider, positive stride width may increase the degree of external rotation on the lead knee in a loaded state, which can place the medial side of the knee (and meniscus) at higher risk of injury. Clinical Relevance: Decreasing stride width may be beneficial for professional pitchers to reduce the rate of lower extremity injury, while also preserving performance metric outcomes.

Background: As the indications for and the volume of arthroscopic rotator cuff repair increase, it is important to optimize perioperative care to minimize postoperative complications and health care costs. Purpose: We sought to investigate if the anesthesia type used affects the rate of postoperative complications in patients undergoing arthroscopic rotator cuff repairs. Methods: We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program database to identify patients undergoing arthroscopic rotator cuff repair from 2014 to 2018. Patients were divided into 3 cohorts: general anesthesia, regional anesthesia, and combined general plus regional anesthesia. Bivariate and multivariate analyses with stepwise technique were performed on data related to patient demographics, smoking history, functional status, medical comorbidities (ie, bleeding disorders, chronic obstructive pulmonary disease, and dialysis), and postoperative outcomes within 30 days of discharge. To assess the independent risk factors for postoperative complications, demographics and medical comorbidities were included in the multivariate analyses for any variables that derived P values Results: Of 24,677 total patients undergoing arthroscopic rotator cuff repair, 15,661 (63.5%) had general anesthesia, 889 (3.6%) had regional anesthesia, and 8127 (32.9%) received combined general plus regional anesthesia. Patients who received general anesthesia rather than regional anesthesia were more frequently white (76.8% vs 74.8%, respectively) and had a medical history of hypertension (47.9% vs 41.8%, respectively), smoking (14.9% vs 12.4%, respectively), and chronic obstructive pulmonary disease (3.4% vs 1.6%, respectively). Compared with patients receiving general anesthesia, those receiving combined general plus regional were more likely to have higher American Society of Anesthesiologists class and a smoking history. Following adjustment, patients who underwent regional anesthesia had a decreased risk for postoperative admission compared with patients who had general anesthesia. Patients who underwent combined regional plus general anesthesia had decreased rates of wound complications and readmission compared with those who received general anesthesia. Conclusion: Among patients undergoing arthroscopic rotator cuff repair, this retrospective study found a significantly higher rate of respiratory and cardiac comorbidities with general anesthesia compared with regional anesthesia. When controlling for these confounders, the use of regional anesthesia was still associated with lower rates of postoperative readmission compared with the general and combined subgroups. Patients receiving combined general plus regional anesthesia had decreased rates of wound complications and readmittance compared with general anesthesia. These findings may influence anesthetic choice in minimizing postoperative complications for rotator cuff repairs.

Background: With the expanded indications for telemedicine, there is increased utility for screening methods to determine which patients are likely to progress to surgical intervention, requiring in-person visits. Patient-rated tools such as the Boston Carpal Tunnel Questionnaire (BCTQ) may be one such tool for screening patients with carpal tunnel syndrome (CTS). The aim of the study was to evaluate whether BCTQ scores were predictive of offering conservative treatment or surgical intervention for CTS. Methods: Patients diagnosed with CTS from January 2017 to February 2020 completed BCTQ questionnaires prior to in-person office visits. Demographics, comorbidities, and highest level of intervention recommended were recorded for each patient as conservative, injection, or surgery. Pearson χ2 and independent-samples t tests were conducted to determine whether BCTQ symptom severity and functional scores were associated with intervention type. Results: A total of 200 patients with CTS were included. Of these, 103 were recommended conservative or injection treatment and 97 were recommended surgery. There were no differences in comorbidities between groups, including other upper extremity pathology ( P = .57), previous upper extremity surgery ( P = .32), hypertension ( P = .17), hypothyroidism ( P = .15), rheumatoid arthritis ( P = .34), and diabetes ( P = .30). Between these groups, there were no differences in BCTQ symptom severity score (symptom severity scale [SSS]; P = .16) or BCTQ functional severity score (functional severity scale [FSS]; P = .96). Conclusions: There is no correlation between comorbidities and BCTQ SSS or FSS score, and offering surgery for CTS. In an era of minimizing non-essential health care visits, the BCTQ is insufficient in screening patients as potential surgical candidates.

Background: Graft failure after osteochondral allograft transplantation (OCA) of the knee is a devastating outcome, often necessitating subsequent interventions. A comprehensive understanding of the risk factors for failure after OCA of the knee may provide enhanced prognostic data for the knee surgeon and facilitate more informed shared decision-making discussions before surgery. Purpose: To perform a systematic review and meta-analysis of risk factors associated with graft failure after OCA of the knee. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: The PubMed, Ovid/MEDLINE, and Cochrane databases were queried in April 2021. Data pertaining to study characteristics and risk factors associated with failure after OCA were recorded. DerSimonian-Laird binary random-effects models were constructed to quantitatively evaluate the association between risk factors and graft failure by generating effect estimates in the form of odds ratios (ORs) with 95% CIs, while mean differences (MDs) were calculated for continuous data. Qualitative analysis was performed to describe risk factors that were variably reported. Results: A total of 16 studies consisting of 1401 patients were included. The overall pooled prevalence of failure was 18.9% (range, 10%-46%). There were 44 risk factors identified, of which 9 were explored quantitatively. There was strong evidence to support that the presence of bipolar chondral defects (OR, 4.20 [95% CI, 1.17-15.08]; P = .028) and male sex (OR, 2.04 [95% CI, 1.17-3.55]; P = .012) were significant risk factors for failure after OCA. Older age (MD, 5.06 years [95% CI, 1.44-8.70]; P = .006) and greater body mass index (MD, 1.75 kg/m2 [95% CI, 0.48-3.03]; P = .007) at the time of surgery were also significant risk factors for failure after OCA. There was no statistically significant evidence to incontrovertibly support that concomitant procedures, chondral defect size, and defect location were associated with an increased risk of failure after OCA. Conclusion: Bipolar chondral defects, male sex, older age, and greater body mass index were significantly associated with an increased failure rate after OCA of the knee. No statistically significant evidence presently exists to support that chondral defect size and location or concomitant procedures are associated with an increased graft failure rate after OCA of the knee. Additional studies are needed to evaluate these associations.

Category: Ankle; Other Introduction/Purpose: Open reduction and internal fixation (ORIF) of the ankle is a common procedure performed to correct ankle fractures in many different patient populations. Diabetes, peripheral vascular disease, and osteoporosis have been identified as risk factors for postoperative complications following surgery for ankle fractures. To date, there have not been any studies evaluating postoperative outcomes in patients with bleeding disorders undergoing operative treatment for ankle fractures. The aim of this study was to determine the postoperative complication rate following ORIF of the ankle in patients with a bleeding disorder versus those without a bleeding disorder. Methods: From 2006 to 2018, patients undergoing operative treatment for ankle fracture were identified in the National Surgical Quality Improvement Program database. Two patient cohorts were defined: patients with a bleeding disorder and patients without a bleeding disorder. Patients who underwent either inpatient or outpatient ORIF of the ankle were included in this study. In this analysis, demographics, medical comorbidities, and postoperative complications variables were assessed between the two cohorts. Bivariate and multivariate analyses were performed. Results: Of 10,306 patients undergoing operative treatment for ankle fracture, 9,909 patients (96.1%) had no bleeding disorder whereas 397 patients (3.9%) had a bleeding disorder. Following adjustment on multivariate analysis, compared to patients who did not have a bleeding disorder, those with a bleeding disorder had an increased risk of any postoperative complications (OR 1.479; p=0.024), requirement for postoperative blood transfusion (OR 2.863; p=0.001), and extended length of hospital stay greater than 5 days (OR 1.455; p=0.010) (Table 1). Conclusion: Patients with bleeding disorders are at an increased risk of postoperative complications following ORIF for ankle fractures. Our study found that patients with bleeding disorders had greater odds of postoperative complications following ORIF of the ankle. Determining patient risk factors and creating optimal preoperative and perioperative management plans in patients with bleeding disorders undergoing ORIF can be beneficial in reducing postoperative complications, improving patient outcomes, and reducing overall cost.

Background: Inefficient energy transfer from the pelvis and trunk has been shown to increase compensation at the level of the shoulder. Kinetic chain sequencing of the core segments is underexamined in professional baseball pitchers, especially as it relates to changes in upper extremity kinetics. Purpose: To evaluate elbow and shoulder kinetics in a cohort of professional pitchers differentiated by instances of discordant pelvic to upper torso sequencing during the pitch. Study Design: Descriptive laboratory study. Methods: 285 professional baseball pitchers were evaluated using 3D motion capture (480 Hz). Pitchers were divided into “chronological” and “discordant” groups based on whether maximum pelvic rotation velocity occurred before (chronological) or after (discordant) maximum upper torso rotation velocity during the pitch motion. Pelvic, upper torso, and shoulder kinematic parameters, shoulder distraction force, shoulder internal rotation torque, and pitch efficiency (PE) were compared between groups. Results: Pitchers with discordant torso sequencing (n = 30; 110 pitches) had greater shoulder horizontal adduction at maximum external rotation (mean difference, 3.6°; 95% CI, −5.2° to −2.0°; t = −4.5; P < .001) and greater maximum shoulder external rotation (mean difference, 3.7°; 95% CI, 5.7° to 1.5°; t = −3.5; P < .001) than chronological pitchers (n = 255; 2974 pitches). PE did not differ between groups ( P = .856), whereas ball velocity was significantly faster in the discordant group (mean difference, 0.6 m/s; 95% CI, −1.1 to −0.3 m/s; t = −3.3; P = .0012). Chronological pitchers had significantly reduced shoulder distraction force (mean difference, −4.7% body weight (BW); 95% CI, −7.9% to −1.5% BW; t = −2.9; P = .004) with no difference in shoulder internal rotation torque ( P = .160). These kinematic and kinetic differences were not observed when accounting for interpitcher variability. Conclusion: Between pitchers, those who had a discordant pelvic to upper torso sequence experienced significantly greater shoulder distraction forces, potentially compensating by increasing maximum shoulder external rotation and horizontal abduction. Achieving maximal pelvic rotation velocity before maximal rotation velocity may be advantageous in preventing compensation at the upper extremity and excessive throwing arm loading. Clinical Relevance: Identifying risk factors for increased upper extremity forces has potential implications in injury prevention. Specifically, mitigating shoulder distraction forces may be beneficial in reducing risk of injury.

Context: Transmission of communicable diseases observed in sporting organizations is often preventable. Early detection, isolation, and treatment can significantly diminish time lost. Until recently, there has been a paucity of standardized guidelines outlining feasible, preventable measures to protect both athletes and staff from contagious illnesses. Therefore, the purpose of this narrative was to highlight optimal prevention practices for transmission mitigation, with a particular focus on hygiene activity and travel considerations in professional sporting organizations. Evidence Acquisition: Current recommendations from the Centers for Disease Control and Prevention and peer-reviewed journals. Study Design: Clinical review. Level of Evidence: Level 5. Results: Communicable illness prevention strategies begin at the level of sufficient personal hygiene practices. Common area surface cleaning recommendations, including shared equipment sanitization between usage as well as designated equipment use to specific athletes, should be considered to minimize cross-contamination, in particular, for liked-position players. Intelligent design for shared areas can include redistributing the layout of communal spaces, most feasibly, spreading locker designation a minimum distance of 6 ft from one another. Travel considerations can include placing most susceptible passengers closest to window seating, boarding last and exiting first. Team physicians should have knowledge of essential personnel medical histories in an effort to risk stratify staff members and players in the setting of communicable disease. Conclusion: Providing a framework for illness management and prevention is important when considering the effects on player health, missed time, performance, and overall cost. Containment of commonly observed communicable illnesses can be optimized with sufficient personal hygiene practices, common area surface cleaning recommendations, intelligent design for shared areas, travel and hotel considerations, as well as appropriate screening tools and isolation techniques. Strength of Recommendation Taxonomy (SORT): B.

Background The relationships between shoulder abduction and external rotation with peak kinetic values at the shoulder and elbow in professional baseball pitchers are not well established. Methods Professional pitchers ( n = 322) threw 8–12 fastballs under 3D motion analysis (480 Hz). Pitchers were stratified into quartiles by shoulder abduction and external rotation at distinct timepoints. Regression analyses were performed to quantify associations between shoulder position and kinetics. Results Shoulder abduction remained relatively consistent throughout the pitch (foot contact–ball release: 85.5 ± 11.1–90.7 ± 8.4°); shoulder external rotation increased dramatically (foot contact–ball release: 30.8 ± 24.6–165.2 ± 9.7°). For every 10° increase in maximum shoulder rotation, shoulder superior force increased by 2.3% body weight ( p 0.05). For every 10° increase in shoulder abduction at ball release, shoulder superior force increased by 3.7% body weight ( p Conclusion Increased shoulder abduction at ball release and increased maximum shoulder external rotation were associated with greater superior and distraction forces in the shoulder. Pitchers can consider decreasing shoulder abduction at later stages of the pitch to around 80° in order to minimize shoulder superior force, with no impact on ball velocity.

Background: It has previously been speculated that baseball pitchers who display excessive forearm pronation at foot contact (FC) have a higher propensity toward ulnar collateral ligament injury and subsequent surgery. Purpose: To evaluate the association between degree of forearm pronation/supination at FC and throwing arm kinetics in high school and professional pitchers, at both the individual (intrapitcher) and the group (interpitcher) level. Study Design: Descriptive laboratory study. Methods: High school (n = 41) and professional (n = 196) pitchers threw 8 to 12 fastballs while being assessed with a 3-dimensional motion-capture system (480 Hz). Pitchers at each playing level were divided into a supination or pronation subgroup depending on degree of forearm pronation at FC. Regression models were built to observe the relationship between forearm pronation at FC and kinetic and kinematic parameters of interest. Results: At both the individual and the group level of high school and professional pitchers, there was no significant correlation between forearm pronation at FC and elbow varus torque ( P min = .21). For every 10° increase in forearm pronation at FC in the individual high school pitcher, elbow flexion at FC decreased by 5°, whereas maximum elbow extension velocity was achieved 0.6% later in the pitch. In addition, elbow medial force increased by 4.1 N and elbow varus torque increased by 0.8 N·m for every 10° increase in forearm supination at FC. For every 10° increase in forearm supination in the individual professional pitcher, ball velocity increased by 0.5 m/s, shoulder external rotation at FC decreased by 11°, and elbow medial force decreased by 5.5 N. Conclusion: Supination- or pronation-predominant forearm motion during the pitch did not significantly differ between playing levels. Excessive forearm pronation at FC was not a significant risk factor for increased throwing arm kinetics for high school or professional pitchers. There was a weak positive association between forearm supination at FC and elbow varus torque in the individual high school pitcher. Ultimately, coaches and pitchers may be better served by redirecting their focus to other mechanical aspects of the pitch that may have stronger associations with injury risk implications as well as performance.

Objectives: Completion of an interval throwing program (ITP) is a common benchmark for return to full competition following an injury to the dominant extremity of an overhead throwing athlete. While workload management for overhead athletes has evolved, the general structure of the ITP remains relatively unexamined. Furthermore, the daily and cumulative workload of ITPs is generally unknown. An ideal ITP would allow for a gradual increase in workload that eventually approximates, but does not exceed, workload measurements attained during competition. It is currently unknown if ITPs achieve this critically important objective. Therefore, the current study sought to 1) determine the daily and cumulative workload for common ITPs using elbow varus torque (EVT), and 2) compare EVT experienced during completion of ITPs to game pitching EVT values. Methods: A retrospective review identified high school pitchers with at least 50 throws at distances of 90, 120, 150, and 180 feet plus game pitches while wearing a MotusBASEBALL sensor. Averages for EVT per throw and torque per minute were calculated at each distance. Three throwing programs were created using a template of one phase at each distance with two steps per phase (Table 1). Programs varied only by number of throws per set (20, 25, and 30 throws for Programs A, B, and C, respectively). Total EVT for each step, phase, and program were calculated using average EVT values for each distance. Total torque for each step and program was converted to an average inning pitched equivalent (IPE) and maximum pitch count equivalent (MPE), respectively, using pitching EVT values and expected average pitch counts (16 pitches/inning and maximum 105 pitches/game). Results: 3,447 throws were analyzed from 7 pitchers with an average age of 16.7 yrs (0.8 yrs SD). EVT progressively increased with distance (range 36.9-45.5 N·m), comparable to game pitching (45.7 N·m). Average torque per minute was highest for 90 ft throws (193.4 N·m/min) and lowest for game pitches (125.0 N·m/min). Program A demonstrated the lowest range of IPE per step (2.0-3.7), and Program C had the highest range (3.0-5.6) (Figure 1). The phases of Program A never exceeded 1MPE. Program B exceeded this threshold after phase 1, and Program C exceeded 1MPE at every phase (Figure 2). Total program MPE ranged from 3.5 (Program A) to 5.2 (Program C). Conclusions: Performing long-toss throwing led to greater torque per minute compared to gameday pitching. Additionally, ITPs requiring 25 or more throws per set led to increased cumulative EVT, especially at distances greater than 150 ft, which can exceed typical values from gameday pitching. ITPs should be adjusted accordingly to encourage a slower pace of long-toss throws and less than 25 throws per set, especially at distances greater than 120 ft. Most ITPs currently recommend one rest day between steps. However, cumulative EVT at longer distances can exceed 5 IPE. Most pitch count rules require more than one rest day after a pitching outing that exceeds multiple innings pitched. Therefore, days off between steps and phases of an ITP should reflect these demands. We advocate for multiple days off between steps that require more than 3 IPE. Table 2 presents a novel ITP based on the findings of the current study.

Background: Open debridement (OD) of the extensor carpi radialis brevis tendon, both with and without repair to the lateral epicondyle, are effective treatments for recalcitrant lateral epicondylitis. However, few comparative studies exist within the literature. Purpose: To (1) compare the 5-year reoperation rates of patients who underwent OD alone versus OD with tendon repair (ODR) and (2) identify the 90-day adverse event rates, total same-day reimbursement amounts, and national usage trends for these 2 procedures from 2010 to 2019. Study Design: Cohort study; Level of evidence, 3. Methods: The PearlDiver MUExtr database was reviewed for patients diagnosed with lateral epicondylitis who underwent OD alone and ODR or reattachment between January 2010 and December 2019. These patients were stratified into 2 cohorts: the OD cohort and ODR cohort. The 5-year reoperation rates were assessed and compared, and the incidence of 90-day postoperative complications and risk factors were identified. The number of ODs and ODRs performed each year and the mean same-day reimbursement amounts (in US$) for both procedures were assessed. Results: Overall, 41,932 lateral epicondylitis patients who underwent debridement were identified, with 17,139 OD patients and 24,793 ODR patients. There were no significant changes in the proportion of OD versus ODR procedures performed during the study period ( P = .18). A significantly higher incidence of hematoma was seen after OD compared with ODR (0.19% vs 0.12%; P = .04), but ODR had a significantly lower 5-year reoperation rate than OD (2.8% vs 3.9%; P = .006), with an absolute risk reduction of 1.1% and a number needed to treat of 91. Finally, ODR ($1683.17 ± $12.15) had a higher mean same-day reimbursement than OD ($1479.05 ± $15.78) ( P = .001). Conclusion: Both OD and ODR had low complication rates. The 5-year reoperation rates were low for both procedures, but they were significantly higher for OD. Over the 10-year study period, there were no significant changes in the relative percentages of OD versus ODR performed. ODR had a significantly higher mean same-day reimbursement.

Background: Repetitive horizontal shoulder abduction during pitching can cause increased contact between the posterosuperior aspect of the glenoid and the greater tuberosity of the humeral head, theoretically putting baseball pitchers at increased risk of shoulder internal impingement and other shoulder pathologies. Hypothesis: Increased shoulder horizontal abduction is associated with increased shoulder anterior force, while increased horizontal adduction is associated with increased shoulder distraction force. Study Design: Descriptive laboratory study. Level of Evidence: Level 4. Methods: A total of 339 professional baseball pitchers threw 8 to 10 fastball pitches using 3D motion capture (480 Hz). Pitchers were divided into 2 sets of quartiles based on maximum shoulder horizontal abduction and adduction. Elbow flexion, shoulder external rotation, and peak shoulder kinetics were compared between quartiles with post hoc linear regressions conducted for the entire cohort. Results: At maximum shoulder horizontal abduction, there was no difference in ball velocity between quartiles ( P = 0.76). For every 10º increase in maximum shoulder horizontal abduction, shoulder anterior force decreased by 2.2% body weight (BW) ( P < 0.01, B = −0.22, β = −0.38), shoulder adduction torque decreased by 0.5%BW × body height (BH) ( P < 0.01, B = −0.05, β = −0.19), and shoulder horizontal adduction torque decreased by 0.4%BW × BH ( P < 0.01, B = −0.04, β = −0.48). For every 10º increase in maximum shoulder horizontal adduction, shoulder anterior force increased by 2%BW and ball velocity decreased by 1.2 m/s (2.7 MPH). Conclusion: Professional pitchers with the least amount of maximum horizontal adduction had faster ball velocity and decreased shoulder anterior force. Pitchers with greater maximum shoulder horizontal abduction had decreased shoulder anterior force, shoulder adduction torque, and shoulder horizontal adduction torque. To maximize ball velocity as a performance metric while minimizing shoulder anterior force, pitchers can consider decreasing maximum shoulder adduction angles at later stages of the pitch. Clinical Relevance: Identifying risk factors for increased throwing shoulder kinetics (ie, shoulder anterior force, shoulder adduction torque) has potential implications in injury prevention. Specifically, mitigating shoulder anterior forces may be beneficial in reducing risk of injury.

Background Excessive shoulder anterior force has been implicated in pathology of the rotator cuff in little league and professional baseball pitchers; in particular, anterior laxity, posterior stiffness, and glenohumeral joint impingement. Distinctly characterized motions associated with excessive shoulder anterior force remain poorly understood. Methods High school and professional pitchers were instructed to throw fastballs while being evaluated with 3D motion capture (480 Hz). A supplementary random forest model was designed and implemented to identify the most important features for regressing to shoulder anterior force, with subsequent standardized regression coefficients to quantify directionality. Results 130 high school pitchers (16.3 ± 1.2 yrs; 179.9 ± 7.7 cm; 74.5 ± 12.0 kg) and 322 professionals (21.9 ± 2.1 yrs; 189.7 ± 5.7 cm; 94.8 ± 9.5 kg) were included. Random forest models determined nearly all the variance for professional pitchers (R2 = 0.96), and less than half for high school pitchers (R2 = 0.41). Important predictors of shoulder anterior force in high school pitchers included: trunk flexion at maximum shoulder external rotation (MER) (X.IncMSE = 2.4, β = −0.23, p Conclusion A random forest model successfully selected a subset of features that accounted for the majority of variance in shoulder anterior force for professional pitchers; however, less than half of the variance was accounted for in high school pitchers. Temporal and kinematic movements at the shoulder were prominent predictors of shoulder anterior force for both groups. Clinical relevance : Our statistical model successfully identified a combination of features with the ability to adequately explain the majority of variance in anterior shoulder force among high school and professional pitchers. To minimize shoulder anterior force, high school pitchers should emphasize decreased shoulder abduction at BR, while professionals can decrease shoulder horizontal adduction at FC.

Category: Ankle; Arthroscopy; Basic Sciences/Biologics; Sports; Trauma Introduction/Purpose: Osteochondral lesions of the talus (OCLT) are common traumatic injuries and can be difficult to treat. Conventional methods consist of arthroscopic debridement and bone marrow stimulation techniques including microfracture, curettage, abrasion chondroplasty and antegrade/retrograde drilling predominantly leading to fibrocartilage formation. These methods have proved effective for small lesions; however, larger lesions with accompanying subchondral bone cysts require more invasive treatment with osteochondral allografts or autologous chondrocyte implantation. These procedures can require harvesting of osteochondral grafts from the knee or malleolar osteotomies, which have associated donor site morbidities and complications of osteotomy healing. We describe an alternative method, an all-arthroscopic technique to treat these large cystic OCLTs, and sought to determine long-term quality of life metrics for a cohort of patients. Methods: From 2010-2012, six patients with difficult to treat OCLTs underwent arthroscopic-assisted implantation of particulated juvenile allograft cartilage with viable chondrocytes (DeNovo NT) along with autogenous bone grafting from the calcaneus by a single surgeon. These lesions all had associated cystic changes requiring bone graft to fill the defect. Other inclusion criteria included at least two of the following: 1) shoulder lesions, 2) lesion size > 200 mm2, 3) failed previous microfracture treatment, or 4) age > 40 with a Body Mass Index (BMI) > 25 kg/m2. These six patients were fully evaluated using physical examination, patient interviews, and outcome score measures. Follow-up was completed at 2 years, 4 years, and between 6-9 years at their most recent visit. Pre-operative and post-operative functional outcome scores were compared with Wilcoxon Signed Ranked Test. Results: Six patients (age: 43.8 + 14.0 years, BMI: 28.4 + 6.7 kg/m2) had average lesion sizes of 188.5 + 50.9 mm2 (range: 125-260 mm2) and most recent follow-up of 8.4 + 1.2 years (range: 6.0-9.3 years). Post-operatively, average VAS pain scores decreased by 4.2 points, 95% CI [1.6-6.8]. FAAM ADL scores improved from 41.8 to 72.5, 95% CI [11.3-50.1]. SF-36 Physical Component Scores also showed significant improvement by 37.8 points, 95% CI [20.8-54.8]. FAAM Sports (p = 0.055) and AOFAS (p = 0.066) scores clinically improved from 13.3 to 39.2 and 57.7 to 86.3, respectively, and approached statistical significance. There were no intraoperative or perioperative complications with calcaneal bone grafting. Conclusion: A small cohort of patients followed over the course of ~8 years after implantation of particulated juvenile allograft cartilage (DeNovo NT) and autogenous calcaneal bone graft for cystic OCLTs had positive post-operative, self-reported functional outcomes. Patients significantly improved compared to pre-operative measures, with no complications observed. This may be an effective long-term treatment for patients with difficult to treat OCLTs.