Evaluation and Management of Glenohumeral Instability in Adolescent Patients: An Expert Consensus Statement.

Background: Management of glenohumeral instability in the adolescent population can be both challenging and controversial. There are no current guidelines for optimal management of glenohumeral instability in this population (unidirectional or multidirectional), and the cutoff ages for transition to adult treatment are not known. Purpose: To develop consensus-based guidelines for the management of glenohumeral instability in adolescents. Study Design: Consensus statement. Methods: A 26-question, multiple-choice survey was developed after 2 rounds of iterations and was submitted to the orthopaedic surgeons of the Pediatric Research in Sports Medicine (PRiSM) Society. The survey comprised 3 sections-demographics, practice setting, and decision-making-and included cutoff ages and management in 5 specific case scenarios. Consensus-based guidelines were generated with 66% response agreement. An indication score was then applied to each response related to more aggressive management to determine if variables related to consensus (or lack thereof) could be identified. Results: A total of 54 responses were returned. Of the respondents, 59% were from academic practice, 84% were pediatric orthopaedic fellowship trained, and 46% performed >25 shoulder instability cases per year. In the setting of first-time anterior shoulder dislocation, nonoperative treatment was preferred for boys aged <14 years and girls aged <13 years. Besides age, proximal humerus physeal status, injury mechanism, sport, and presence of bony injury affected treatment selection. The presence of a Bankart lesion was an indication for stabilization in first-time dislocations for contact athletes with a closing or closed physis, but not in patients with an open physis or noncontact injury mechanisms. For recurrent anterior shoulder dislocation, stabilization was preferred irrespective of physis status. Initial nonoperative treatment was preferred for multidirectional instability. Conclusion: In the setting of first-time anterior shoulder dislocation in patients with open physes, nonoperative treatment was preferred for boys <14 years and girls <13 years. Future multicenter prospective studies focusing on outcomes would help to validate current practice patterns, especially in scenarios for which no consensus was reached.

Medial femoral condyle OCD (osteochondritis dissecans): correlation between imaging and arthroscopy.

Osteochondritis dissecans (OCD) describes a pathologic condition centered at the osteochondral junction that may result in an unstable subchondral fragment (progeny), disruption of the overlying cartilage, which may separate from the underlying parent bone. It is one of the causes of chronic knee pain in children and young adults. The current literature on OCD lesions focuses primarily on the medial femoral condyle (MFC), but inconsistent use of terminology, particularly in the distinction of OCD lesions between skeletally immature and mature patients has created uncertainty regarding imaging workup, treatment, and long-term prognosis. This article reviews the pathophysiology of MFC OCD lesions, highlighting the role of endochondral ossification at the secondary growth plate of the immature femoral condyles, the rationale behind the imaging work-up, and key imaging findings that can distinguish between stable lesions, unstable lesions, and physiologic variants. This overview also provides a case-based review to introduce imaging correlates with the ROCK (Research in Osteochondritis of the Knee) arthroscopic classification.

The Role of the Lead Hip in Collegiate Baseball Pitching: Implications for Ball Velocity and Upper-Extremity Joint Moments.

Hip flexibility is an important biomechanical factor for a baseball pitcher. However, there have been limited investigations into the association between upper-extremity joint stresses and ball velocity and hip flexibility, as assessed via motion patterns during the pitch. The purpose of this study was to provide a detailed kinematic description of the lead hip during the pitch and determine the association between lead hip motion and both ball velocity and the elbow varus moment. This study was a secondary analysis of the kinematic and kinetic data previously collected on 99 collegiate-level baseball pitchers using standard optoelectronic motion capture. Significant associations were noted between lead hip internal rotation and both peak ball velocity and the elbow varus moment. The data indicated that for every 10° increase in internal lead hip rotation, ball velocity increased by 0.6 m/s (P < .001, r2 = .26), and the elbow varus moment increased by 5 N·m (P < .001, r2 = .33). The results of this study suggested that internal hip rotation may be an important means of identifying pitchers that may be at risk for future injury.

MRI Features That Contribute to Decision-Making for Treatment of Capitellar OCD Lesions: An Expert Consensus Using the Delphi Method.

Background: Most healthcare providers utilize magnetic resonance imaging (MRI) to assist in diagnosing and treating osteochondritis dissecans (OCD) of the capitellum. However, consensus on imaging features that portend clinically relevant information in the care of these lesions has not been determined. Purpose: To conduct a survey on the MRI features of a capitellar OCD that are salient for clinical decision-making using a classic Delphi protocol. Study Design: A consensus statement. Methods: Invitations to participate were sent to 33 healthcare providers identified as capitellar OCD experts. A classic 3-round survey method was used to gather agreement and consensus on the level of importance for clinical decision-making on 33 MRI features. A concise list of features that guide decision-making on the stability of an OCD lesion and the ability of an OCD lesion to heal with nonoperative care was also identified. Agreement and consensus were determined a priori as ≥66%. Results: Of the 33 identified experts, 20 agreed to participate, and 17 (52%) completed all 3 rounds. Of the 33 MRI features evaluated, 17 reached agreement as important for clinical decision-making by the experts. Consensus was reached for a concise list of MRI features that were significant to decision-making (94%), suggestive of a stable lesion (100%), had the potential to heal with nonoperative treatment (94%), were suggestive of an unstable lesion (100%), and had low potential to heal with nonoperative treatment (88%). Conclusion: This 3-round Delphi process produced consensus on clinically relevant MRI features that contribute to clinical decision-making for capitellar OCD. The results of this study will be used as the basis for an interrater reliability assessment of the identified salient features, creating the foundation for developing a reliable MRI assessment tool rooted in clinical experiences. The development of a standardized assessment of capitellar OCD is intended to improve clinical practice and patient outcomes.

Preoperative Bladder Scanning Can Predict Postoperative Urinary Retention Following Total Joint Arthroplasty.

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.

Liposomal bupivacaine provides superior pain control compared to bupivacaine with adjuvants in interscalene block for total shoulder replacement: a prospective double-blinded, randomized controlled trial.

INTRODUCTION: Optimal pain control methods after total shoulder arthroplasty (TSA) achieve reduced opioid consumption, shortened hospital stay, and improved patient satisfaction in addition to adequate analgesia. Interscalene brachial plexus block is the gold standard for TSA, yet it typically does not provide pain relief lasting beyond 24 hours. Liposomal bupivacaine (LB) purportedly provides prolonged analgesia, yet it has been minimally explored for interscalene block, and it is significantly more expensive than standard bupivacaine. METHODS: This is a prospective, 2-arm, double-blinded randomized controlled trial. Subjects presenting for anatomic or reverse TSA were randomized in a 1:1 ratio to receive interscalene brachial plexus block with either LB plus bupivacaine (LBB group) or bupivacaine plus dexamethasone and epinephrine (BDE group). The primary outcome was 120-hour postoperative opioid consumption. Secondary outcomes were pain scores up to 96 hours postoperatively, pain control satisfaction, complications, level of distress from block numbness, and hospital stay. RESULTS: Ninety patients, 45 per group, were included in the intention-to-treat analysis and randomized. Because of withdrawal of consent and loss to follow-up, 40 in each group completed enrollment through postoperative day 60. Total 120-hour postoperative opioid consumption was similar between groups (P = .127), with no differences within 24- or 48-hour time intervals. Postoperative pain scores at 24-48 hours, 48-72 hours, 72-96 hours, and day 60 were significantly lower for the LBB group. DISCUSSION: LB interscalene brachial plexus block before total shoulder arthroplasty did not reduce 120-hour postoperative opioid consumption but significantly reduced postoperative pain between 24 and 96 hours and at postoperative day 60.

Transarticular Versus Retroarticular Drilling of Stable Osteochondritis Dissecans of the Knee: A Prospective Multicenter Randomized Controlled Trial by the ROCK Group.

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).

The influence of trunk mechanics on the assessment of elbow position in college aged pitchers.

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.

Reliability of Radiographic Imaging Characteristics for Osteochondritis Dissecans of the Capitellum.

BACKGROUND: A primary challenge in the treatment of capitellar osteochondritis dissecans (OCD) is accurate imaging assessment. Radiographic classification consensus is not available in the current literature, and correlation of radiographs with lesion stability and resultant best treatment is lacking. PURPOSE: To determine the inter- and intrarater reliability of the presence or absence and common radiographic characteristics of capitellar OCD lesions. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: Anteroposterior, lateral, and oblique radiographs for 29 cases were reviewed by 7 orthopaedic surgeons. Images were assessed for elbow anthropometry and morphology, OCD presence, lesion characteristics, the presence of progeny bone and progeny features, and radial head abnormalities. Intra- and interrater reliability was assessed using Fleiss and Cohen kappa for nominal variables and intraclass correlation coefficients (ICCs) for continuous variables. RESULTS: Surgeons demonstrated substantial to excellent inter- and intrarater reliability when assessing elbow characteristics: anthropometric (interrater ICC, 0.94-0.99; intrarater ICC, 0.82-0.96) and morphologic (Fleiss, 0.61-0.76; Cohen, 0.68). When the OCD lesion was assessed, fair to moderate interrater agreement was found for classifying the absence or presence of a lesion (Fleiss, 0.28-0.46) and the location of the OCD (Fleiss, 0.24-0.52), poor agreement for assessing the contour of the lesion (Fleiss, 0.00-0.09), and excellent agreement for measuring the size of the lesion (ICC, 0.82-0.94). Poor to fair interrater agreement was found for radial head abnormalities (Fleiss, 0.00-0.27). Progeny bone visualization and fragmentation demonstrated moderate interrater agreement (Fleiss, 0.43-0.47) where displacement of the bone demonstrated poor interrater agreement (Fleiss, 0.11-0.16). Intrarater agreement for OCD lesion characteristics, progeny bone visualization, and progeny bone features was moderate to excellent. CONCLUSION: Given only the fair to moderate agreement among raters for identifying OCD on radiographs, this imaging modality may not serve as a dependable screening tool in isolation. Additional imaging should be obtained if the clinical presentation suggests capitellar OCD and a definitive diagnosis is not possible with radiographs. However, clinicians can reliability measure the size of radiographically apparent OCD, suggesting that radiographs may serve as an appropriate imaging modality for follow-up care.

Lead knee flexion angle is associated with both ball velocity and upper extremity joint moments in collegiate baseball pitchers.

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.

Lead Foot Progression Angle in Baseball Pitchers: Implications to Ball Velocity and Upper-Extremity Joint Moments.

The instant of foot contact is an important transition point during the pitch cycle between the linear portion of the pitch, as a pitcher strides down the mound and the rotational portion of the pitch. Understanding the implications of lead foot angle at foot contact is an essential information needed to assist pitching coaches in their work with individual pitchers. Therefore, the purpose of this study was to determine the association between lead foot progression angle at foot contact and ball velocity, elbow varus moment, and pelvic rotation. Kinematic and kinetic data were collected from 99 collegiate pitchers and analyzed using a random intercept, mixed-effects regression model. Significant associations were found between lead foot progression angle at foot contact and elbow varus moment (P = .004), as well as pelvic rotation throughout the pitching motion (P < .001). The data indicate that increased lead foot internal rotation at foot contact is associated with increases in the elbow varus moment but is not associated with ball velocity. This study provides scientific evidence that the rotational positioning of the lead foot can affect both pelvic motion and upper-extremity joint moments.

Preoperative Factors to Assess Risk for Postoperative Urinary Retention in Total Joint Arthroplasty: A Retrospective Analysis.

BACKGROUND: Postoperative urinary retention (POUR) is a significant problem in total joint arthroplasty (TJA). Although risk factors for POUR have been well documented, they are ubiquitous in an aging total joint population, which makes risk stratification difficult. The purpose of this study was to determine if a high preoperative post-void bladder scan identifies patients at risk for POUR. METHODS: A retrospective analysis was conducted on all TJAs performed at a high-volume orthopedic center between December 2019 and February 2020. A total of 585 elective TJA patients received post-void bladder scans before surgery. Bladder scan volumes were correlated with catheterization via Chi-squared tests. RESULTS: A high post-void residual volume (PVRV > 50 ml) was associated with an increased risk of catheterization (23% vs 34%, chi-squared statistic = 6.2638, P value = .013), as was intravenous fluid volume (>1000 ml in knee, >2000 ml in hip). Catheterization rates were higher among total knee arthroplasty patients younger than 60 years (37% vs 24%, chi-squared statistic = 4.284, P value = .0385) and total hip arthroplasty (THA) patients older than 65 years (30% vs 18%, chi-squared statistic = 3.292, P value = .0695). Multiple risk factors were additive. CONCLUSIONS: Higher PVRV and intravenous fluids were independently associated with catheterization after TJA. Younger age was associated with greater risk in total knee arthroplasty, while older age increased risk in THA. We propose that a preoperative bladder scan to detect a high PVRV may provide clinical utility to identify patients likely to develop POUR.

Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort.

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.

Elbow flexion post ball release is associated with the elbow varus deceleration moments in baseball pitching.

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.

Male and Female Adolescent Athletes' Readiness to Return to Sport After Anterior Cruciate Ligament Injury and Reconstruction.

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.

Deceleration phase elbow varus moments: a potential injury mechanism for collegiate baseball pitchers.

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.

Osteochondritis Dissecans of the Knee: An Interrater Reliability Study of Magnetic Resonance Imaging Characteristics.

BACKGROUND: Imaging characteristics of osteochondritis dissecans (OCD) lesions quantified by magnetic resonance imaging (MRI) are often used to inform treatment and prognosis. However, the interrater reliability of clinician-driven MRI-based assessment of OCD lesions is not well documented. PURPOSE: To determine the interrater reliability of several historical and novel MRI-derived characteristics of OCD of the knee in children. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: A total of 42 OCD lesions were evaluated by 10 fellowship-trained orthopaedic surgeons using 31 different MRI characteristics, characterizing lesion size and location, condylar size, cartilage status, the interface between parent and progeny bone, and features of both the parent and the progeny bone. Interrater reliability was determined via intraclass correlation coefficients (ICCs) with 2-way random modeling, Fleiss kappa, or Krippendorff alpha as appropriate for each variable. RESULTS: Raters were reliable when the lesion was measured in the coronal plane (ICC, 0.77). Almost perfect agreement was achieved for condylar size (ICC, 0.93), substantial agreement for physeal patency (ICC, 0.79), and moderate agreement for joint effusion (ICC, 0.56) and cartilage status (ICC, 0.50). Overall, raters showed significant variability regarding interface characteristics (ICC, 0.25), progeny (ICC range, 0.03 to 0.62), and parent bone measurements and qualities (ICC range, -0.02 to 0.65), with reliability being moderate at best for these measurements. CONCLUSION: This multicenter study determined the interrater reliability of MRI characteristics of OCD lesions in children. Although several measurements provided acceptable reliability, many MRI features of OCD that inform treatment decisions were unreliable. Further work will be needed to refine the unreliable characteristics and to assess the ability of those reliable characteristics to predict clinical lesion instability and prognosis.

Predictive Role of Symptom Duration Before the Initial Clinical Presentation of Adolescents With Capitellar Osteochondritis Dissecans on Preoperative and Postoperative Measures: A Systematic Review.

BACKGROUND: Osteochondritis dissecans (OCD) of the capitellum is an increasingly recognized disease affecting young athletes. Because lesion progression is common, early identification is potentially beneficial for an athlete's treatment and recovery. However, there is currently no analysis available that evaluates the impact of symptom duration on preoperative and postoperative outcomes. PURPOSE/HYPOTHESIS: The purpose of this study was to perform a systematic review of surgically treated OCD lesions to examine the effect of symptom duration before the initial presentation on preoperative and postoperative outcomes. We hypothesized that a longer symptom duration would correlate with more severe preoperative signs and symptoms and poorer postoperative outcomes. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Ovid MEDLINE, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and the Database of Abstracts of Reviews of Effects were queried for studies evaluating symptom duration before the clinical presentation of capitellar OCD and surgical outcomes. A systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: A total of 23 studies reporting outcomes in 258 patients (mean patient age, 14.4 ± 1.5 years) were analyzed. Locking as a chief complaint predominated in a greater proportion of patients who presented with a longer history of OCD symptoms (P = .007). A longer symptom duration also correlated with a longer time to return to sport (P = .008) and older age (P < .001). Range of motion limitations as both a chief complaint and a physical examination finding correlated with a longer symptom duration (P = .014 and .001, respectively). Symptom duration did not show a relationship with most postoperative outcomes, including the return-to-sport rate (P = .172), which ranged from 70.7% to 91.1% depending on the surgical procedure performed. No significant difference was observed between symptom duration and the surgical procedure performed (P = .376). CONCLUSION: Advanced OCD lesions were observed in patients with a longer symptom duration. However, treatment specifics rather than symptom duration correlated best with return to sport for patients with advanced OCD lesions requiring surgery. The earlier detection of capitellar OCD may be valuable in reducing the severity of lesions, the time to return to sport, and potential need for surgery in young athletes.

Sagittal Plane Trunk Tilt Is Associated With Upper Extremity Joint Moments and Ball Velocity in Collegiate Baseball Pitchers.

BACKGROUND: The trunk is a major contributor to the kinetic chain during baseball pitching by helping to transfer energy from the lower limbs to produce the desired ball speed. However, most of the research detailing the trunk's contribution to the pitch is focused on rotational timing and coronal plane lean, with little attention focused on sagittal plane positioning of the trunk. PURPOSE: To determine the association between sagittal plane trunk motion and elbow varus moment and ball velocity in collegiate baseball pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 99 collegiate pitchers were recruited for this study and underwent a comprehensive biomechanical assessment of their pitching motion using 3-dimensional motion techniques. A random-intercepts, mixed-effects regression model was used to determine whether statistically significant associations were noted between sagittal plane trunk motion and the ball velocity and elbow varus moment. RESULTS: There were a number of significant associations between sagittal plane trunk tilt and the elbow varus moment and ball velocity. Increased forward trunk tilt at the time of ball release was associated with an increase in elbow varus moment and a small increase in ball velocity; for every 10° of increased forward trunk tilt greater than 28° at ball release, the elbow varus moment increased by 2.9 N·m (P = .007), and the ball velocity increased by 0.7 m/s (P = .002). CONCLUSION: Sagittal plane positioning of the trunk plays a role in pitching mechanics, as it can affect both pitching performance and elbow moments. The results also indicated that there is a potential optimal trunk position and range of motion during the acceleration of the pitch that could limit the stress placed on the elbow joint. Implementing proper trunk mechanics from an early age could lead to a reduction in joint moments. CLINICAL RELEVANCE: The results provide evidence for coaches and trainers to emphasize the importance of proper trunk positioning through the inclusion of core strengthening and motor control in their practice and coaching sessions in an effort to reduce the moments placed on the elbow during the pitch.

Biomechanical Comparison of Epiphyseal Anterior Cruciate Ligament Fixation Using a Cortical Button Construct Versus an Interference Screw and Sheath Construct in Skeletally Immature Cadaveric Specimens.

BACKGROUND: Anterior cruciate ligament (ACL) ruptures have become increasingly common in pediatric and adolescent athletes. While multiple methods exist, all-epiphyseal ACL reconstruction is a popular technique in the skeletally immature patient. Given the high rate of reruptures in this population and the increasing number of commercially available fixation devices, biomechanical testing is crucial to understand the performance of these devices in pediatric epiphyseal bone. To our knowledge, there has not been a biomechanical analysis of ACL fixation devices in skeletally immature bone. PURPOSE: To compare cortically based button fixation with interference screw and sheath fixation in skeletally immature femoral epiphyseal cadaveric bone. Our hypothesis was that there would be no difference in peak load to failure, stiffness, or cyclic displacement between these 2 fixation constructs. STUDY DESIGN: Controlled laboratory study. METHODS: Fresh-frozen matched-pair knees from 3 pediatric cadaveric specimens were obtained. A synthetic graft was fixed in an all-epiphyseal femoral tunnel. Both the lateral and medial condyles were utilized to increase the sample size. Specimens were randomized and assigned to receive either an interference screw and sheath construct designed for pediatric patients or an adjustable loop cortical button. Biomechanical testing was performed to obtain ultimate load to failure, stiffness, total displacement after 500 cycles, and the failure mode for each condyle. RESULTS: Each medial and lateral condyle in 3 pairs of skeletally immature cadaveric knees (ages 7, 9, and 11 years) was utilized for testing. One specimen was excluded after it failed by having a transphyseal fracture. The median peak load to failure was 769.80 N (interquartile range [IQR], 628.50-930.41 N) for the screw and sheath group and 862.80 N (IQR, 692.34-872.65 N) for the button group (P = .893). The median displacement after 500 cycles for the screw and sheath group was 0.65 mm (IQR, 0.47-1.03 mm) and 1.13 mm (IQR, 0.96-1.25 mm) for the button group (P = .08). The median stiffness of the screw and sheath group was significantly higher than that of the button group (31.47 N/mm [IQR, 26.40-43.00 N/mm] vs 25.22 N/mm [IQR, 21.18-27.07 N/mm], respectively) (P = .043). CONCLUSION: When comparing femoral fixation with a screw and sheath construct developed for pediatric patients to an adjustable loop cortical button in skeletally immature bone, our results showed that fixation did not significantly differ with respect to cyclic displacement or peak load to failure. While the screw and sheath construct was significantly stiffer, its effect on clinical outcomes is not yet known. CLINICAL RELEVANCE: With regard to femoral fixation, there is no significant biomechanical difference between the use of cortically based button fixation or interference screw and sheath fixation in pediatric epiphyseal cadaveric bone.