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Background: Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease. Purpose: To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest. Results: As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases. Conclusion: The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms. [ABSTRACT FROM AUTHOR]

Background: As total joint arthroplasty (TJA) moves to the outpatient setting, it is becoming clear that postoperative urinary retention (POUR) is a potential impediment to same-day discharge. Although risk factors for POUR have been widely studied, the lack of their clinical utility warrants investigation of specific preoperative factors that can assist in surgical planning and patient optimization. The purpose of the current study was to determine whether preoperative symptom surveys and bladder scanning are useful tools in identifying POUR risk. Methods: We performed a prospective analysis of patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) at a high-volume orthopaedic hospital between December 1, 2020, and September 30, 2021. A total of 507 patients (324 female and 183 male) undergoing TJA completed the American Urological Association (AUA) symptom index preoperatively and then again at 14 and 64 days postoperatively. Post-void bladder scans were obtained in the immediate preoperative setting. POUR was defined as a bladder volume of >500 mL that required catheterization. Chi-square and quintile analysis were used to compare bladder scanning volumes, and Student t tests were used to compare AUA scores. Results: The rate of POUR was 37% (66 female and 34 male) and 23% (37 female and 19 male) in the TKA and THA groups, respectively. Increasing post-void residual volume (PVRV) measured on preoperative bladder scanning was found to be predictive of POUR. Among the TKA cohort, younger age and lower body mass index were also associated with increased catheterization, although age was not statistically significant. The AUA symptom survey was not found to correlate with POUR in either population. Conclusions: There was a predictable and exponential increase in the rate of catheterization as preoperative PVRV increased from 50 to 200 mL. The AUA symptom score showed no utility in predicting POUR in our study population. We propose that preoperative bladder ultrasonography become standard practice in TJA, especially among patients scheduled for same-day discharge. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: The incidence of shoulder and elbow injuries in adolescent baseball players is rapidly increasing. One leading theory about this increase is that breaking pitches (such as the curveball) place increased moments on the dominant arm and thereby increase the risk of injury. Hypothesis: There is no difference in the moments at the shoulder and elbow between fastball and curveball pitches in adolescent baseball pitchers. Study Design: Controlled laboratory study. Methods: Thirty-three adolescent baseball pitchers with a minimum of 2 years of pitching experience underwent 3-dimensional motion analysis using reflective markers aligned to bony landmarks. After a warm-up, pitchers threw either a fastball or curveball, randomly assigned, from a portable pitching mound until 3 appropriate trials were collected for each pitch technique. Kinematic and kinetic data for the upper extremities, lower extremities, thorax, and pelvis were collected and computed for both pitch types. Statistical analysis included both the paired sample t test and mixed model regression. Results: There were lower moments on the shoulder and elbow when throwing a curveball versus when throwing a fastball. As expected, speed for the 2 pitches differed: fastball, 65.8 ± 4.8 mph; and curveball, 57.7 ± 6.2 mph (P < .001). Maximal glenohumeral internal rotation moment for the fastball was significantly higher than for the curveball (59.8 ± 16.5 N·m vs 53.9 ± 15.5 N·m; P < .0001). Similarly, the maximum varus elbow moment for the fastball was significantly higher than for the curveball (59.6 ± 16.3 N·m vs 54.1 ± 16.1 N·m; P < .001). The wrist flexor moment was greater in the fastball, 8.3 ± 3.6 N·m, than in the curveball, 7.8 ± 3.6 N·m (P < .001), but the wrist ulnar moment was greater in the curveball, 4.9 ± 2.0 N·m, than in the fastball, 3.2 ± 1.5 N·m (P < .001). Relatively minor motion differences were noted at the shoulder and elbow throughout the pitching motion, while significant differences were seen in forearm and wrist motion. The forearm remained more supinated at each point in the pitching cycle for the curveball but had less overall range of motion (62° ± 20°) than with the fastball (69° ± 17°) (P < .001), and the difference in the forearm pronation and supination moment between the pitches was not significant (P = .104 for pronation and P = .447 for supination). The wrist remained in greater extension during the fastball from foot contact through ball release but did not have significantly different total sagittal range of motion (53° ± 11°) when compared with the curveball (54° ± 15°) (P = .91). Conclusion: In general, the moments on the shoulder and elbow were less when throwing a curveball than when throwing a fastball. In each comparison, the fastball demonstrated higher moments for each individual pitcher for both joints. Clinical Relevance: The findings based on the kinematic and kinetic data in this study suggest that the rising incidence of shoulder and elbow injuries in pitchers may not be caused by the curveball mechanics. Further evaluation of adolescent and adult baseball pitchers is warranted to help determine and subsequently reduce the risk of injury. [ABSTRACT FROM AUTHOR]

A three-dimensional biomechanical analysis on baseball pitching technique among adolescent is presented. The purpose of the study was to understand the etiology of injuries common to adolescent baseball pitchers. Kinetic and kinematics data for the lower and upper extremities, thorax, and pelvis of 24 adolescent pitchers were collected and analyzed using three-dimensional computerized motion analysis. Result of the measurements of motion of forearm, wrist shoulders, thorax and pelvic are analyzed. It is concluded that the measured parameters and the difference between adolescent and adult pitchers can be used to determine causes of pitching injuries.

The incidence of elbow injury experienced by baseball pitchers is on the rise. Biomechanical investigations focusing on the acceleration phase of the pitch have yet to elucidate a singular cause for these injuries. Leading to the question is there an additional significant stress on the elbow during other phases of the pitch? This study sought to determine the magnitude of the elbow varus moment during the deceleration phase of the pitching cycle for the fastball, curveball, slider and change-up. Eighty-seven collegiate-level pitchers were evaluated using motion analysis techniques to determine the magnitude of the elbow varus moment occurring during the deceleration phase. The results indicated that the elbow varus moment during the deceleration phase of the pitch was typically between 40% and 50% of the peak acceleration phase moment and was greatest when throwing a slider. Results also indicated that more pitchers experienced deceleration phase moments in excess of 50% of the acceleration moment when throwing breaking pitches. These moments which are the result of the pitchers' need to rapidly decelerate their arm produce an additional significant elbow varus moment that results in additional stress to the elbow. [ABSTRACT FROM AUTHOR]

Researchers have postulated that the rise in the incidence of pitching injuries is partially due to poor pitching mechanics. A topic that is often debated revolves around the correct positioning of the elbow in relationship to the body. Therefore, this study attempts to understand the associations of vertical or horizontal elbow positon with upper extremity joint moments, and ball velocity, and how elbow position is influenced by trunk position. Motion analysis data from 99 collegiate pitchers were analysed for this study. A random intercept, mixed-effects regression model was used to determine if statistically significant associations existed between elbow position and upper extremity joint moments and ball velocity. Results indicated that visual impressions of the elbow position were highly correlated with trunk position, whereas kinematic definitions of elbow position were correlated to the glenohumeral angle. Visual vertical and horizontal elbow position was associated with increased elbow varus moments (p = 0.001) and ball velocity (p = 0.019), respectively. Whereas kinematic elbow position was not associated with either upper extremity joint moments or ball velocity. Therefore, what coaches visually interpret as an improperly positioned elbow may actually be a combination of lateral lean, anterior tilt, and over rotation of the trunk. [ABSTRACT FROM AUTHOR]

Background: When stable osteochondritis dissecans (OCD) lesions of the femoral condyle in a skeletally immature patient fail to heal with nonoperative methods, the standard of care treatment is condylar OCD drilling. Two primary OCD drilling techniques have been described, but no prospective studies have compared their relative effectiveness. Purpose/Hypothesis: The purpose of this study was to compare the healing and function after transarticular drilling (TAD) with that after retroarticular drilling (RAD). It was hypothesized that there would be no difference in rate or time to healing, rate or time to return to sports, patient-reported outcomes (PROs), or secondary OCD-related surgery. Study Design: Randomized controlled clinical trial; Level of evidence, 1. Methods: Skeletally immature patients with magnetic resonance imaging–confirmed stable OCD lesions of the medial femoral condyle who did not demonstrate substantial healing after a minimum of 3 months of nonoperative treatment were prospectively enrolled by 1 of 17 surgeon-investigators at 1 of 14 centers. Patients were randomized to the TAD or RAD group. Tourniquet time, fluoroscopy time, and complications were compared between the treatment groups. Postoperatively, serial radiographs were obtained every 6 weeks to assess healing, and PROs were obtained at 6 months, 12 months, and 24 months. Results: A total of 91 patients were included, consisting of 51 patients in the TAD and 40 patients in the RAD group, who were similar in age, sex distribution, and 2-year PRO response rate. Tourniquet time and fluoroscopy time were significantly shorter with TAD (mean, 38.1 minutes and 0.85 minutes, respectively) than RAD (mean, 48.2 minutes and 1.34 minutes respectively) (P =.02; P =.004). In the RAD group, chondral injury from K-wire passage into the intra-articular space was reported in 9 of 40 (22%) patients, but no associated postoperative clinical sequelae were identified in these patients. No significant differences between groups were detected in follow-up Pediatric–International Knee Documentation Committee, Lysholm, Marx Activity Scale, or Knee injury and Osteoarthritis Outcome Score Quality of Life scores. Healing parameters were superior at 6 months and 12 months in the TAD group, compared with the RAD group, and secondary OCD surgery occurred in 4% of patients who underwent TAD and 10% of patients who underwent RAD (P =.40). Patients in the TAD group returned to sports earlier than those in the RAD group (P =.049). Conclusion: TAD showed shorter operative time and fluoroscopy time and superior healing parameters at 6 and 12 months, but no differences were seen in 24-month healing parameters or PROs at all follow-up time points, when compared with RAD. Registration: NCT01754298 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Background: The incidence of upper extremity injury in baseball pitchers has increased over the past decade. This has resulted in a large body of research mainly focused on the kinematic and kinetic patterns of the elbow and shoulder to elucidate the cause of these injuries, with little attention on studying the associations of forearm rotation and upper arm joint moments. Hypothesis: There will be significant differences in forearm kinematics and kinetics when comparing the fastball pitch with the curveball pitch. There will be a positive association between forearm kinetics, specifically supination and pronation moments, and the elbow varus moment. Study Design: Descriptive laboratory study. Methods: A total of 78 pitchers were recruited for this study, and they underwent a pitching analysis using motion analysis techniques. A random-intercept, mixed-effects regression model was used to determine differences in forearm kinematics and kinetics when pitching a fastball compared with a curveball, as well as to determine if associations existed between forearm supination and pronation moments and the elbow varus moment. Results: There were a number of significant differences in forearm position when pitching a fastball compared with a curveball, with the curveball producing a more supinated forearm position. Significant associations were found between increasing forearm supination moments and an increase in elbow varus moment for both the fastball and the curveball (P = .002 and P < .001, respectively). For every 1-N·m increase in the supination moment, there was a 1-N·m and 1.1-N·m increase in the elbow varus moment for the fastball and curveball, respectively. Conclusion: The results demonstrated that the forearm position was not associated with the elbow varus moment. However, the supination moment was associated with the elbow varus moment. Clinical Relevance: On the basis of these findings, pitching coaches and trainers can understand the implications of proper lower arm pitching mechanics in the later portion of the pitch cycle as a potential risk of injury and, therefore, can develop coaching strategies to reduce incorrect positioning, especially when players are pitching the curveball. [ABSTRACT FROM AUTHOR]

Left-handed baseball pitchers are thought to have a number of theoretical advantages compared to right-handed pitchers; however, there is limited scientific research detailing differences in the pitching mechanics of right- and left-handed pitchers. Therefore, this study sought to understand whether any kinematic and kinetic differences existed between right- and left-handed baseball pitchers. A total of 52 collegiate pitchers were included in this study; 26 left-handed pitchers were compared to 26 age-, height-, weight- and ball velocity-matched right-handed pitchers. Demographic information, passive shoulder range of motion and kinematic and kinetic data were obtained for each pitcher participating in the study. Results indicated that left-handed pitchers did not have a glenohumeral internal rotation deficit as compared to right-handed pitchers. Kinematic analysis indicated that elbow flexion, horizontal glenohumeral abduction and wrist coronal plane motion were significantly different between the two study cohorts. It was also noted that left-handed pitchers had increased elbow varus moments. The findings of this study suggest that pitching coaches should be aware that there are biomechanical differences between left- and right-handed pitchers. [ABSTRACT FROM AUTHOR]

An important aspect of the pitching motion is the lead leg knee angle, from initial lead foot contact to ball release, which can influence pitching performance and injury potential. Understanding the implication of this angle is essential to appropriately coach baseball pitchers. Therefore, the purpose of this study was to determine the lead leg knee flexion influence on both ball velocity and the elbow varus moment. Kinematic and kinetic data were collected using standard optoelectronic motion capture methods from 121 collegiate pitchers and analysed using a random intercept, mixed effects regression model to evaluate the association between the knee angle on peak ball velocity and peak elbow varus moment, independently. Statistically significant associations between the knee flexion angle and ball velocity as well as with the elbow varus moment were noted. The data indicated that a 10° increase in knee flexion at ball was associated with a 2.1 Nm reduction in the peak elbow varus moment (p = 0.021, r2 = 0.12) and a 0.2 m/s reduction in peak ball velocity (p = 0.010, r2 = 0.11). This study provides scientific evidence that the lead knee flexion angle influences both upper extremity stresses and ball velocity. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to examine whether readiness to return to sport (RTS) differed between adolescent male and female athletes after anterior cruciate ligament reconstruction (ACLR). Design: Longitudinal, prospective cohort. Setting: Outpatient office associated with tertiary-care hospital. Patients: A total of 93 adolescent athletes, 17 years of age and younger, who underwent ACLR surgery with a hamstring autograft were included. Independent Variables: Male and female athletes. Main Outcome Measures: Anterior cruciate ligament--return to sport after injury (ACL-RSI) completed at 3 time points: (1) preoperatively (Pre-op), (2) approximately 3 months into rehabilitation (Post-op 1), and (3) during RTS phases of recovery (Post-op 2). Results: There was a significant main effect for both sex (P < 0.010) and time (P < 0.0001) with male athletes having higher ACL-RSI scores than female athletes at all 3 time points; however, there was no significant time by sex interaction. All ACL-RSI scores increased significantly across time, regardless of sex. There were no statistically significant differences between ACL-RSI scores at all 3 time points between individuals who did and did not receive physician clearance. Conclusions: This study provides a longitudinal depiction of adolescent athletes' readiness to RTS after ACL injury throughout recovery. Both male and female athletes demonstrated diminished ACL-RSI scores before undergoing surgery, with increasing scores at both postoperative time points for both sexes. Overall, female athletes reported lower readiness to RTS at all 3 time points compared with male athletes. [ABSTRACT FROM AUTHOR]

The association between breaking pitches and elbow injury remains nebulous. Biomechanical studies have shown that throwing a fastball rather than a curveball results in greater elbow moments, despite some epidemiological studies and pitcher self-report indicating the opposite. This leads to the following question: Are biomechanical studies missing something that could explain this discrepancy? This study evaluated the association between elbow kinematics of baseball pitchers during the deceleration phase of the pitch and the elbow varus moment. Eighty-seven uninjured collegiate pitchers were analysed using 3-dimensional motion capture techniques. Results indicated that pitchers who remained in greater elbow flexion had greater post ball release elbow varus moments (EVMPBR) (p = 0.001). Regression analysis indicated that for every 10° of increased elbow flexion during follow-through the EVMPBR increased by 5.4 Nm for the fastball and 8.2 Nm for the curveball (p < 0.001). This suggests a concerning second stress on the elbow joint occurring during the deceleration phase of the pitch. The results showed that maintaining greater elbow flexion during the deceleration phase of the pitch can substantially increase the elbow varus moment after ball release (BR), especially when pitching the curveball. The results reinforce the need to emphasise appropriate pitching mechanics. [ABSTRACT FROM AUTHOR]

Background: Access to health care services is a critical component of health care reform and may differ among patients with different types of insurance. Hypothesis/Purpose: The purpose was to compare adolescents with private and public insurance undergoing surgery for anterior cruciate ligament (ACL) and/or meniscal tears. We hypothesized that patients with public insurance would have a delayed presentation from the time of injury and therefore would have a higher incidence of chondral injuries and irreparable meniscal tears and lower preoperative International Knee Documentation Committee (IKDC) scores than patients with private insurance. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This was a retrospective study of patients under 21 years of age undergoing ACL reconstruction and/or meniscal repair or debridement from January 2013 to March 2016 at a single pediatric sports medicine center. Patients were identified by a search of Current Procedural Terminology (CPT) codes. A chart review was performed for insurance type; preoperative diagnosis; date of injury, initial office visit, and surgery; preoperative IKDC score; intraoperative findings; and procedures. Results: The study group consisted of 119 patients (mean age, 15.0 ± 1.7 years). Forty-one percent of patients had private insurance, while 59% had public insurance. There were 27 patients with isolated meniscal tears, 59 with combined meniscal and ACL tears, and 33 with isolated ACL tears. The mean time from injury to presentation was 56 days (range, 0-457 days) in patients with private insurance and 136 days (range, 0-1120 days) in patients with public insurance (P = .02). Surgery occurred, on average, 35 days after the initial office visit in both groups. The mean preoperative IKDC score was 53 in both groups. Patients with meniscal tears with public insurance were more likely to require meniscal debridement than patients with private insurance (risk ratio [RR], 2.3; 95% CI, 1.7-3.1; P = .02). Patients with public insurance were more likely to have chondral injuries of grade 2 or higher (RR, 4.4; 95% CI, 3.9-5.0; P = .02). Conclusion: In adolescent patients with ACL or meniscal tears, patients with public insurance had a more delayed presentation than those with private insurance. They also tended to have more moderate-to-severe chondral injuries and meniscal tears, if present, that required debridement rather than repair. More rapid access to care might improve the prognosis of young patients with ACL and meniscal injuries with public insurance. [ABSTRACT FROM AUTHOR]

Background: The reliability of assessing healing on plain radiographs has not been well-established for knee osteochondritis dissecans (OCD). Purpose: To determine the inter- and intrarater reliability of specific radiographic criteria in judging healing of femoral condyle OCD. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Ten orthopedic sports surgeons rated the radiographic healing of 30 knee OCD lesions at 2 time points, a minimum of 1 month apart. First, raters compared pretreatment and 2-year follow-up radiographs on “overall healing” and on 5 subfeatures of healing, including OCD boundary, sclerosis, size, shape, and ossification using a continuous slider scale. “Overall healing” was also rated using a 7-tier ordinal scale. Raters then compared the same 30 pretreatment knee radiographs in a stepwise progression to the 2-, 4-, 7-, 12-, and 24-month follow-up radiographs on “overall healing” using a continuous slider scale. Interrater and intrarater reliability were assessed using intraclass correlations (ICC) derived from a 2-way mixed effects analysis of variance for absolute agreement. Results: Overall healing of the OCD lesions from pretreatment to 2-year follow-up radiographs was rated with excellent interrater reliability (ICC = 0.94) and intrarater reliability (ICC = 0.84) when using a continuous scale. The reliability of the 5 subfeatures of healing was also excellent (interrater ICCs of 0.87-0.89; intrarater ICCs of 0.74-0.84). The 7-tier ordinal scale rating of overall healing had lower interrater (ICC = 0.61) and intrarater (ICC = 0.68) reliability. The overall healing of OCD lesions at the 5 time points up to 24 months had interrater ICCs of 0.81-0.88 and intrarater ICCs of 0.65-0.70. Conclusion: Interrater reliability was excellent when judging the overall healing of OCD femoral condyle lesions on radiographs as well as on 5 specific features of healing on 2-year follow-up radiographs. Continuous scale rating of OCD radiographic healing yielded higher reliability than the ordinal scale rating. Raters showed substantial to excellent agreement of OCD overall radiographic healing measured on a continuous scale at 2, 4, 7, 12, and 24 months after starting treatment. [ABSTRACT FROM AUTHOR]

Background: Several systems have been proposed for classifying osteochondritis dissecans (OCD) of the knee during surgical evaluation. No single classification includes mutually exclusive categories that capture all of the salient features of stability, chondral fissuring, and fragment detachment. Furthermore, no study has assessed the reliability of these classification systems. Purpose: To determine the intra- and interobserver reliability of a novel, comprehensive arthroscopic classification system with mutually exclusive OCD lesion types. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The Research in OsteoChondritis of the Knee (ROCK) study group developed a classification system for arthroscopic evaluation of OCD of the knee that includes 6 arthroscopic categories—3 immobile types and 3 mobile types. To optimize comprehensibility and applicability, each was developed with a memorable name, a brief description, a line diagram corresponding to the archetypal arthroscopic appearance, and an arthroscopic photograph depicting this archetype. Thirty representative arthroscopic videos were evaluated by 10 orthopaedic surgeon raters, who classified each lesion. After 4 weeks, the raters again classified the OCD lesions depicted in the 30 videos in a new, randomly selected order. Reliability was assessed via the intraclass correlation coefficient (ICC). Results: The interobserver reliability of this novel arthroscopy classification was estimated by an ICC of 0.94 (95% CI, 0.91-0.97) for the first round and 0.95 (95% CI, 0.93-0.98) for the second round. According to the standards for the magnitude of the reliability coefficient of Altman, these ICCs indicate that interobserver reliability was very good. The intraobserver reliability was estimated by an ICC of 0.96 (95% CI, 0.95-0.97), which indicates that the intraobserver reliability was similarly very good. Conclusion: The ROCK OCD knee arthroscopy classification system demonstrated excellent intra- and interobserver reliability. In light of this reliability, this classification system may be used clinically and to facilitate future research, including multicenter studies for OCD. [ABSTRACT FROM AUTHOR]

Background: The incidence of upper extremity injuries in baseball pitchers is increasing. Over the past decade there has been a great deal of research attempting to elucidate the cause of these injuries, focusing mainly on the mechanics of the pitching arm with no examination of other key segments, such as the trunk. This is surprising, as coaches will often comment on trunk position in an effort to improve pitching outcomes. Purpose: To determine the association between contralateral trunk lean and ball velocity and the moments about the elbow and glenohumeral joint. Study Design: Descriptive laboratory study. Methods: A total of 99 pitchers were recruited for this study and underwent a pitching analysis using 3-dimensional motion analysis techniques. A random intercept mixed-effects regression model was used to determine if statistically significant associations existed between contralateral trunk lean (away from the pitching arm side) and ball velocity, as well as the elbow varus moment and glenohumeral internal rotation moment. Results: The results demonstrated that the greatest contralateral trunk lean occurs around the time of the peak elbow varus moment. Statistically significant associations were found between contralateral trunk lean and increased ball velocity (P = .003) indicating that for every 10 increase in contralateral lean, ball velocity increased 0.5 m/s. Results also indicated that for every 10 increase in contralateral lean, elbow varus moments increased by 3.7 Nm and glenohumeral internal rotation moments increased by 2.5 Nm (P \ .001 for both). Conclusion: Study findings indicate that the positioning of the trunk plays a substantial role in pitching performance and pitcher injury potential. This work helps to demonstrate the importance of proper trunk mechanics in pitching and highlights the need for future research to understand the contribution of the trunk to pitching mechanics. Clinical Relevance: Pitching coaches and trainers can use the results of this study to stress the importance of proper trunk mechanics in pitching. Specifically, improving core strength and trunk control in an effort to maintain a more upright posture through the pitching cycle can reduce upper extremity joint stresses. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reconstruction failure occurs in up to 10% of cases. Technical errors are considered the most common cause of graft failure despite the absence of validated studies. Limited data are available regarding the agreement among orthopaedic surgeons regarding the causes of primary ACL reconstruction failure and accuracy of graft tunnel Placement.Hypothesis: Experienced knee surgeons have a high level of interobserver reliability in the agreement about the causes of primary ACL reconstruction failure, anatomic graft characteristics, and tunnel placement.Study Design: Cohort study (diagnosis); Level of evidence, 3.Methods: Twenty cases of revision ACL reconstruction were randomly selected from the Multicenter ACL Revision Study (MARS)database. Each case included the patient's history, standardized radiographs, and a concise 30-second arthroscopic video taken at the time of revision demonstrating the graft remnant and location of the tunnel apertures. All 20 cases were reviewed by 10 MARS surgeons not involved with the primary surgery. Each surgeon completed a 2-part questionnaire dealing with each surgeon's training and practice, as well as the placement of the femoral and tibial tunnels, condition of the primary graft, and the surgeon's opinion as to the causes of graft failure. Interrater agreement was determined for each question with the kappa coefficient and the prevalence-adjusted, bias-adjusted kappa (PABAK).Results: The 10 reviewers have been in practice an average of 14 years and have performed at least 25 ACL reconstructions per year, and 9 were fellowship trained in sports medicine. There was wide variability in agreement among knee experts as to the specific causes of ACL graft failure. When participants were specifically asked about technical error as the cause for failure, inter-observer agreement was only slight (PABAK = 0.26). There was fair overall agreement on ideal femoral tunnel placement (PABAK= 0.55) but only slight agreement on whether a femoral tunnel was too anterior (PABAK = 0.24) and fair agreement on whether it was too vertical (PABAK = 0.46). There was poor overall agreement for ideal tibial tunnel placement (PABAK = 0.17).Conclusion: This study suggests that more objective criteria are needed to accurately determine the causes of primary ACL graft failure as well as the ideal femoral and tibial tunnel placement in patients undergoing revision ACL reconstruction. [ABSTRACT FROM AUTHOR]

Current pitching literature focuses primarily on the elbow and glenohumeral joints. This has led to a paucity of information regarding the forearm and wrist, and the limited data available are inconsistent. Therefore, this article seeks to provide a comprehensive description of the kinematics and kinetics of the wrist and forearm for the fastball, curveball, slider/cutter, and change-up for college-level baseball pitchers. Thirty-six collegiate pitchers were evaluated using motion analysis techniques. Results indicated that pitching the curveball generated the greatest forearm supination (16 ± 13°) compared with the other three pitch types (p < 0.05). The curveball and slider/cutter were pitched with less wrist extension and greater ulnar deviation compared with the fastball and change-up. The curveball was found to produce the greatest ulnar moment (7.3 ± 2.2 Nm) and was significantly different from the moments noted when pitching the fastball and change-up (5.1 ± 1.9 and 4.9 ± 1.9 Nm, respectively;p < 0.05). These results indicate that it may be possible to objectively determine pitch type from kinematic data of the wrist and forearm. It may also be possible that coaches may be able to identify abnormal pitching mechanics from more proximal segments by understanding the motion of the wrist. [ABSTRACT FROM PUBLISHER]

The article presents a study which examines the responsiveness of the International Knee Documentation Committee Subjective Knee Form (IKDC SKF) which is a patient-reported knee-specific outcome measure for patients with knee conditions. It notes that reliability was assessed by administering 17 individuals who had undergone articular cartilage surgery 5 years. Moreover, IKDC SKF is a reliable alternative as a knee-specific instruments for patients undergoing articular cartilage surgery.

Presents information on a study which evaluated the mechanical integrity of different patellar tendon repair techniques under cyclic loading. Materials and methodology of the study; Results of the study; Conclusions.