Anterior-Posterior Laxity in Midflexion After Posterior-Stabilized TKA Is Sensitive to MCL Tension in Passive Flexion: An in Vitro Biomechanical Study.

BACKGROUND: Knee instability in midflexion may contribute to patient dissatisfaction following total knee arthroplasty (TKA). Midflexion instability involves abnormal motions and tissue loading in multiple planes. Therefore, we quantified and compared the tensions carried by the medial and lateral collateral ligaments (MCL and LCL) following posterior-stabilized (PS) TKA through knee flexion, and then compared these tensions with those carried by the native knee. Finally, we examined the relationships between collateral ligament tensions and anterior tibial translation (ATT). METHODS: Eight cadaveric knees (from 5 male and 3 female donors with a mean age of 62.6 years and standard deviation of 10.9 years) underwent PS TKA. Each specimen was mounted to a robotic manipulator and flexed to 90°. ATT was quantified by applying 30 N of anterior force to the tibia. Tensions carried by the collateral ligaments were determined via serial sectioning. Robotic testing was also conducted on a cohort of 15 healthy native cadaveric knees (from 9 male and 6 female donors with a mean age of 36 years and standard deviation of 11 years). Relationships between collateral ligament tensions during passive flexion and ATT were assessed via linear and nonlinear regressions. RESULTS: MCL tensions were greater following PS TKA than in the native knee at 15° and 30° of passive flexion, by a median of ≥27 N (p = 0.002), while the LCL tensions did not differ. Median tensions following PS TKA were greater in the MCL than in the LCL at 15°, 30°, and 90° of flexion, by ≥4 N (p ≤ 0.02). Median tensions in the MCL of the native knee were small (≤11 N) and did not exceed those in the LCL (p ≥ 0.25). A logarithmic relationship was identified between MCL tension and ATT following TKA. CONCLUSIONS: MCL tensions were greater following PS TKA with this typical nonconforming PS implant than in the native knee. Anterior laxity at 30° of flexion was highly sensitive to MCL tension during passive flexion following PS TKA but not in the native knee. CLINICAL RELEVANCE: Surgeons face competing objectives when performing PS TKA: they can either impart supraphysiological MCL tension to reduce anterior-posterior laxity or maintain native MCL tensions that lead to heightened anterior-posterior laxity, as shown in this study.

An Analysis of Intrapitch Variation in Joint and Segment Velocities With Throwing Arm Kinetics in High School and Professional Baseball Pitchers.

BACKGROUND: Improper sequencing order of maximal joint and segment velocities has been identified as an important predictor for both throwing arm kinetics and ball velocity. PURPOSE: To investigate the intrapitcher variation of maximal segment velocities and the relationship to throwing arm kinetics and ball velocity in high school (HS) and professional (PRO) pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: HS (n = 59) and PRO (n = 338) pitchers, instructed to throw 8 to 12 fastball pitches, were evaluated with 3-dimensional motion capture (480 Hz). Maximal joint and segment velocities were calculated for each pitch, and the standard deviation of the maxima was calculated per pitcher. These standard deviations were used to classify pitchers as "low variance" or "high variance" for each segmental velocity subgroup, "overall low variance" or "overall high variance" based on cumulative segment velocity variation, or "population," with any pitcher eligible to be included in multiple subcategories. Maximal velocities and throwing arm kinetics were compared among the various subgroups. RESULTS: The HS low-variance shoulder internal rotation velocity subgroup (4949 ± 642 deg/s) had significantly lower maximal shoulder internal rotation velocity compared with HS population (5774 ± 1057 deg/s) (P < .001); similar findings were observed for PROs (5269 ± 835 vs 5824 ± 1076 deg/s; P < .001), as well as lower shoulder superior force compared with the PRO population (14.8% ± 8.8% vs 17.8% ± 8.8% body weight; P = .001). The PRO low-variance lead knee extension velocity subgroup had significantly lower maximal lead knee extension velocity (216 ± 135 vs 258 ± 125 deg/s; P = .001) and shoulder distractive force (111.5% ± 14.4% vs 115.6% ± 15.9% body weight; P = .003) compared with the PRO population. The PRO overall low-variance subgroup had significantly lower shoulder distractive force (111.8% ± 14.1% vs 119.6% ± 15.5% body weight; P = .008) and elbow anterior force (40.6% ± 5.0% vs 43.6% ± 6.2% body weight; P = .008) compared with the PRO overall high-variance subgroup. CONCLUSION: HS and PRO pitchers with low variance for joint and segment velocities achieved significantly lower maximal velocities in the subgroup of interest, while preserving ball velocity. PRO pitchers with overall low variance among multiple maximal joint and segment velocities demonstrated decreased shoulder distractive and elbow anterior force. CLINICAL RELEVANCE: PRO pitchers with low intrapitch variation in maximal joint and segment velocities may be viewed as kinetically conservative throwers. These pitchers with similarly maintained mechanics between pitches may have an increasingly regimented form that preserves kinetic forces about the throwing arm. The opposite may be true for PRO pitchers with increased variability in segmental velocities during their pitching motion, as they showed increased throwing arm kinetics including shoulder distractive and elbow anterior force compared with the overall low-variance group, theoretically increasing their risk of injury.

Pitch-classifier model for professional pitchers utilizing 3D motion capture and machine learning algorithms.

Introduction: A pitcher's ability to achieve pitch location precision after a complex series of motions is of paramount importance. Kinematics have been used in analyzing performance benefits like ball velocity, as well as injury risk profile; however, prior utilization of such data for pitch location metrics is limited. Objective: To develop a pitch classifier model utilizing machine learning algorithms to explore the potential relationships between kinematic variables and a pitcher's ability to throw a strike or ball. Methods: This was a descriptive laboratory study involving professional baseball pitchers (n = 318) performing pitching tests under the setting of 3D motion-capture (480 Hz). Main outcome measures included accuracy, sensitivity, specificity, F1 score, positive predictive value (PPV), and negative predictive value (NPV) of the random forest model. Results: The optimized random forest model resulted in an accuracy of 70.0 %, sensitivity of 70.3 %, specificity of 48.5 %, F1 equal to 80.6 %, PPV of 94.3 %, and a NPV of 11.6 %. Classification accuracy for predicting strikes and balls achieved an area under the curve of 0.67. Kinematics that derived the highest % increase in mean square error included: trunk flexion excursion(4.06 %), pelvis obliquity at foot contact(4.03 %), and trunk rotation at hand separation(3.94 %). Pitchers who threw strikes had significantly less trunk rotation at hand separation(p = 0.004) and less trunk flexion at ball release(p = 0.003) compared to balls. The positive predictive value for determining a strike was within an acceptable range, while the negative predictive value suggests if a pitch was determined as a ball, the model was not adequate in its prediction. Conclusions: Kinematic measures of pelvis and trunk were crucial determinants for the pitch classifier sequence, suggesting pitcher kinematics at the proximal body segments may be useful in determining final pitch location.

Relationships between throwing mechanics and shoulder anterior force in high school and professional baseball pitchers.

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, ß = -0.23, p < 0.001), shoulder external rotation at ball release (BR)(X.IncMSE = 1.7, ß = -0.34, p < 0.001), and shoulder abduction at BR (X.IncMSE = 3.1, ß = 0.17, p < 0.001). In professional pitchers, shoulder horizontal adduction at foot contact (FC) was the highest predictor (X.IncMSE = 13.9, ß = 0.50, p < 0.001), followed by shoulder external rotation at FC (X.IncMSE = 3.6, ß = 0.26, p < 0.001), and maximum elbow extension velocity (X.IncMSE = 8.5, ß = 0.19, p < 0.001). 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.

Orthopedic surgeon-scientist representation is low among National Institutes of Health grants for rotator cuff research.

Background: The purpose of this study is to characterize National Institutes of Health (NIH) funding for rotator cuff research and evaluate the impact of orthopedic surgeons on this portfolio. Methods: The NIH's Research Portfolio Online Reporting Tools Expenditures and Results database was queried for "rotator cuff repair" or "rotator cuff tear" from the 2011 to 2021 fiscal years. Compound annual growth rates were calculated and grants were categorized by basic, clinical, or translational research. Funding totals were compared by Principal Investigator (PI) and grant characteristics. Results: A total of 52 grants were awarded to 38 PIs between 2011 and 2021, totaling $40,156,859. Annual NIH funding for rotator cuff tear and rotator cuff repair increased by a Compound annual growth rate of 11.0% from 2011 to 2021, compared to 3.4% for the total NIH budget. Orthopedic surgeon-scientists received $9,208,212 (22.9%), most commonly through R01 (80.5%) and K08 (7.1%) mechanisms. No significant difference in funding was found by PI sex (P = .332), degree (P = .460), academic rank (P = .118), or researcher type (P = .227). Professors had a higher h-index than associate and assistant professors (P = .001). Orthopedic surgeon-scientists had a higher h-index (mean 36.3 ± 9.4) compared to clinician-scientists (mean 8.0 ± 1.4) and research-scientists (35.5 ± 40.7) (P = .044). Clinical topics receiving the highest funding were rehabilitation (23.9%), diagnosis, (22.3%) and surgical technique (14.8%). Orthopedic surgeon-scientists acquired funding for diagnosis (57.1%), rehabilitation (17.0%), and surgical technique (14.5%). Discussion: While NIH funding for rotator cuff research is growing, orthopedic surgeon representation is low. Future studies should evaluate barriers to obtaining funding for orthopedic surgeon-scientists.

Long-Term Patient Outcomes for Treatment of Difficult Osteochondral Lesions of the Talus with Particulated Juvenile Allograft Cartilage Implantation ± Calcaneal Autograft: A Cohort Study.

BACKGROUND: Osteochondral lesions of the talus (OCLT) are common injuries that can be difficult to treat. To date, long-term patient reported outcome measures (PROMs) of patients with particulated juvenile allograft cartilage implantation with or without calcaneal autograft have not been compared. METHODS: Thirteen patients with difficult to treat OCLTs underwent arthroscopic-assisted implantation of particulated juvenile allograft cartilage (DeNovo NT®) with or without autogenous calcaneal bone grafting by a single surgeon. Calcaneal bone graft use was determined by lesion size > 150 mm2 and/or deeper than 5 mm. Patients were evaluated using physical examination, patient interviews, and PROMs. RESULTS: When comparing patients in regards to calcaneal bone graft implantation, no difference in age, BMI, pre-operative PROMs, or follow-up was noted, however, calcaneal bone graft patients did have a significantly larger lesion size (188.5 ± 50.9 vs. 118.7 ± 29.4 mm2 respectively; p value = 0.027). VAS and FAAM ADL scores during final follow-up improvement did not significantly differ between cohorts. The FAAM Sports score improved significantly more for the DeNovo alone group compared to the bone graft cohort (p value = 0.032). The AOFAS score improvement did not differ between cohorts (p value = 0.944), however, the SF-36 PCS improved significantly more for the DeNovo alone group compared to the bone graft cohort (p value = 0.038). No intraoperative/perioperative complications were observed with calcaneal bone grafting. CONCLUSION: While patients followed over the course of ~ 8 years after implantation of particulated juvenile allograft cartilage (DeNovo NT®) with/without autogenous calcaneal bone graft had positive post-operative PROMs, patients without calcaneal bone graft had significantly greater improvement in functional outcome scores. Whether these differences are due to graft incorporation or larger lesion size is unclear. LEVEL OF EVIDENCE: III, retrospective cohort study.

Kinematic Parameters Predictive of Pitch Velocity in Youth to Professional Baseball Pitchers: A Qualitative Systematic Review.

Background: Specific kinematic factors have been found to contribute to faster pitch speeds, with poor mechanics leading to injury. Purpose: To discuss the kinematic parameters that predict faster ball velocity among baseball pitchers. Study Design: Systematic review. Methods: Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors utilized the Cochrane Database of Systematic Reviews, PubMed (2008-2019), and OVID/MEDLINE (2008-2019) databases. Eligible articles included those that reported on kinematic factors predictive of ball velocity across youth, high school, collegiate, and professional levels of play. The quality of all included studies was evaluated by 2 reviewers using the Appraisal tool for Cross-Sectional Studies (AXIS). The lack of consistent study design or outcome variables precluded meta-analysis. Results: A total of 584 studies were identified from the initial search with 12 included in final analysis (930 pitchers in total; 429 [46.1%] youth, 164 [17.6%] high school, 153 [16.5%] collegiate and 184 [19.8%] professional) with mean ball velocity of 71.1 mph (114.4 km/h). The average AXIS score was 16 out of a possible 20. The shoulder played a significant role in the generation of velocity-induced torques. Hip and shoulder separation was associated with a 2.6 ± 0.5 mph (4.1 ± 0.8 km/h) increase in velocity, whereas increased shoulder movement of the nonthrowing arm was negatively correlated with initial ball velocity (r2 = 0.798). Furthermore, hip/shoulder separation, decreased movement of the nonthrowing shoulder, trunk power and timing of maximum trunk rotation, increased contralateral trunk tilt and increased sagittal-plane trunk tilt, and decreased knee flexion at ball release were all associated with higher fastball speeds. Conclusion: Multiple upper extremity and trunk kinematic parameters affect ball velocity, with significant contributions from the throwing shoulder and trunk, as well as nondominant arm. Understanding kinematic predictors of faster ball velocity can help guide training regimens.

Kinematic and Kinetic Comparisons of Arm Slot Position Between High School and Professional Pitchers.

Background: Throwing arm kinetics differ in pitchers at varying arm slot (AS) positions (frontal-plane arm position at ball release relative to the vertical axis). Purpose: To determine how kinematic and kinetic values differ between professional and high school pitchers with varying AS positions, and whether these differences are similarly observed in both populations. Methods: High school (n = 130) and professional (n = 288) pitchers threw 8 to 12 fastballs under 3-dimensional motion capture technology. Pitchers in each cohort were subdivided based on mean AS position at ball release: AS1 (least degree of AS: most overhand throwing styles), AS2 (intermediate degree of AS: three-quarter throwing styles), or AS3 (greatest degree of AS: most sidearm throwing styles). Kinetic and kinematic parameters were compared between groups. Study Design: Controlled laboratory study. Results: High school pitchers had a more overhand AS at ball release (50° ± 11°) compared with professional pitchers (58° ± 14°) (P < .001). In both cohorts, AS1 pitchers had significantly greater shoulder abduction (high school, P <0.001; professional, P <0.0001) and lateral trunk flexion (high school, P < 0.001; professional, P <0.0001) at ball release compared with AS3 pitchers. Professional pitchers with an AS3 position had significantly delayed timing of maximum upper trunk angular velocity compared with AS1 pitchers (64% ± 7% vs 57% ± 7% of pitch time, respectively; P < .0001). A significant positive correlation between AS and elbow flexion torque was found in high school pitchers (P = .002; ß = 0.28), and a significant negative correlation between AS and elbow varus torque (P < .001; ß = -0.22) and shoulder internal rotation torque (P < .001; ß = -0.20) was noted in professional pitchers. Conclusion: AS position was related to shoulder abduction and trunk lateral tilt. Professional and high school pitchers with varying AS positions did not experience similar changes in throwing arm kinetics. Clinical Relevance: In professional pitchers, the earlier onset of maximum upper trunk angular velocity with overhand throwing style may reflect inappropriate pelvis-trunk timing separation, a parameter implicated in upper extremity injury, and the negative correlation between AS and elbow varus and shoulder internal rotation torque suggests that both excessive and minimal AS positions have negative implications.

The learning curve for anatomic and reverse total shoulder arthroplasty: a systematic review.

Background: Despite the rising incidence of anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA) among surgeons, little is known about the learning curve associated with these procedures. The purpose of this systematic review was to (1) identify the learning curves associated with ATSA and RTSA, (2) evaluate the effect of the learning curves on clinical outcomes, and (3) determine the number of cases needed to achieve proficiency. Methods: Four online databases [PubMed (NLM), MEDLINE (OVID), Cochrane Library (Wiley), and Scopus (Elsevier)] were systematically searched and screened according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The search included results from the inception of each database to May 18, 2022. Data regarding study characteristics, patient demographics, learning curve analyses, patient reported outcome measures, range of motion, complication rates, and reoperation rates were collected. A quality assessment for each article was performed according to the Methodological Index for Nonrandomized Studies criteria. Results: A total of 13 studies of fair to good quality were included for analysis (one of level II evidence, five of level III, and seven of level IV) with the majority originating from the United States [n = 8, 61.5%]. Overall, there were a total of 3381 cases (1861 RTSA and 1520 ATSA), with a mean patient age of 72.6 years [range: 45-92 years]. From the studies analyzed in this systematic review, for RTSA, the approximate average number of cases surgeons need to perform to move to an acceptable position on the RTSA learning curve is 25 cases. For ATSA, a wider range of 16-86 cases was derived as only two studies reported on ATSA. Conclusion: Progression along the learning curve for RTSA and ATSA results in decreased operative times, improved patient-reported outcomes, and fewer complications. However, a true learning curve is difficult to quantify given the heterogeneity of reported outcome measures, individual surgeon experience at the time of data collection, and statistical analyses used across studies.

Subacromial balloon spacers for the treatment of irreparable rotator cuff tears: a review.

Massive irreparable rotator cuff tears (RCTs) are a commonly encountered orthopedic condition that can be difficult to treat. Several techniques have been described to manage these tears, with the implantable subacromial balloon spacer being one of the most recent. The device, which has only been approved for clinical use in the United States since 2021, functions by resisting the superior humeral head migration seen in the setting of massive RCTs and restoring normal shoulder biomechanics, as corroborated by cadaveric studies. However, results regarding clinical outcomes have been mixed to date, and further high-quality studies are needed to define the optimal use of the subacromial balloon spacer in the treatment of massive irreparable RCTs.

Posterior-stabilized versus mid-level constraint polyethylene components in total knee arthroplasty.

Aims: Mid-level constraint designs for total knee arthroplasty (TKA) are intended to reduce coronal plane laxity. Our aims were to compare kinematics and ligament forces of the Zimmer Biomet Persona posterior-stabilized (PS) and mid-level designs in the coronal, sagittal, and axial planes under loads simulating clinical exams of the knee in a cadaver model. Methods: We performed TKA on eight cadaveric knees and loaded them using a robotic manipulator. We tested both PS and mid-level designs under loads simulating clinical exams via applied varus and valgus moments, internal-external (IE) rotation moments, and anteroposterior forces at 0°, 30°, and 90° of flexion. We measured the resulting tibiofemoral angulations and translations. We also quantified the forces carried by the medial and lateral collateral ligaments (MCL/LCL) via serial sectioning of these structures and use of the principle of superposition. Results: Mid-level inserts reduced varus angulations compared to PS inserts by a median of 0.4°, 0.9°, and 1.5° at 0°, 30°, and 90° of flexion, respectively, and reduced valgus angulations by a median of 0.3°, 1.0°, and 1.2° (p ≤ 0.027 for all comparisons). Mid-level inserts reduced net IE rotations by a median of 5.6°, 14.7°, and 17.5° at 0°, 30°, and 90°, respectively (p = 0.012). Mid-level inserts reduced anterior tibial translation only at 90° of flexion by a median of 3.0 millimetres (p = 0.036). With an applied varus moment, the mid-level insert decreased LCL force compared to the PS insert at all three flexion angles that were tested (p ≤ 0.036). In contrast, with a valgus moment the mid-level insert did not reduce MCL force. With an applied internal rotation moment, the mid-level insert decreased LCL force at 30° and 90° by a median of 25.7 N and 31.7 N, respectively (p = 0.017 and p = 0.012). With an external rotation moment, the mid-level insert decreased MCL force at 30° and 90° by a median of 45.7 N and 20.0 N, respectively (p ≤ 0.017 for all comparisons). With an applied anterior load, MCL and LCL forces showed no differences between the two inserts at 30° and 90° of flexion. Conclusion: The mid-level insert used in this study decreased coronal and axial plane laxities compared to the PS insert, but its stabilizing benefit in the sagittal plane was limited. Both mid-level and PS inserts depended on the MCL to resist anterior loads during a simulated clinical exam of anterior laxity.

Forearm Pronation at Foot Contact: A Biomechanical Motion-Capture Analysis in High School and Professional Pitchers.

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.

Poor evidence is used to support commercial payers' coverage policies for shoulder arthroplasty.

BACKGROUND: The incidence of shoulder arthroplasty has continued to increase over the past decade. In response, commercial payers have implemented strategies to control the medical requirement of these surgeries in attempt to contain the growing costs. For example, most payers require a prolonged trial of conservative management prior to shoulder arthroplasty for patients who may otherwise be surgical candidates. However, little is known regarding the evidence used to support these indications. The purpose of this study was to analyze the references used by commercial payers to substantiate their coverage policies for shoulder arthroplasty. METHODS: Ten of the leading commercial payers for total shoulder arthroplasty were identified. Publicly available coverage policies were searched on the internet or requested directly from the payer via email or telephone. Cited references were reviewed independently by two authors for type of document, level of evidence, and mention of the efficacy of conservative management. RESULTS: A total of 5 coverage policies were obtained with 118 references. The most common reference type was primary journal article (n = 70; 59.3%) followed by review or expert opinion articles (n = 35; 29.7%). Most references were of level IV evidence (n = 60; 52.2%), with only 6 (5.2%) of level I or II evidence. Only 4 (3.5%) references mentioned the efficacy of conservative management in patients who may be candidates for shoulder arthroplasty. CONCLUSION: The majority of references used to substantiate the coverage policies for shoulder arthroplasty among major commercial payers within the United States are of low scientific evidence and fail to demonstrate the success of required nonoperative intervention strategies. Our study underscores the need for high-quality, comparative trials that evaluate the outcomes of conservative management vs. shoulder arthroplasty in end-stage glenohumeral osteoarthritis patients in order to determine the most cost-effective treatment algorithm.

Prospective registration of randomized clinical trials for total shoulder arthroplasty is low: a systematic review.

BACKGROUND: Prospective trial registration has become an important means of improving the transparency and reproducibility of randomized controlled trials (RCTs) and is recommended by the Journal of Shoulder and Elbow Surgery (JSES) per the Consolidated Standards of Reporting Trials (CONSORT) guidelines. Herein, we performed a cross-sectional evaluation of RCTs published in JSES from 2010 to present to determine the prevalence of trial registration and consistency of outcome reporting. METHODS: The electronic database PubMed was searched to identify all RCTs on total shoulder arthroplasty (TSA) published in JSES from 2010 to 2022 using the search terms "randomized controlled trial" AND "shoulder" AND "arthroplasty OR replacement." RCTs were considered to be registered if they provided a registration number. For articles that were registered, authors also extracted the registry name, registration date, date of first enrollment, date of last enrollment, and if the primary outcomes reported in the registry were either (1) omitted, (2) newly introduced in the publication, (3) reported as a secondary outcome or vice versa, or (4) varied in timing of assessment compared to the publication. "Early" RCTs were considered those published from 2010 to 2016, whereas "later" RCTs were from 2017 to 2022. RESULTS: Fifty-eight RCTs met inclusion criteria. There were 16 early RCTs and 42 later RCTs. Twenty-three of the 58 (39.7%) studies were registered, with 9 of 22 with an available registry (40.9%) of those being enrolled prior to patient enrollment. Nineteen of the registered studies (82.6%) provided the name of the registry and a registration number. The proportion of later RCTs that were registered was not significantly different from the early RCTs (45.2% vs. 25.0%, P = .232). Seven RCTs (31.8%) had at least 1 inconsistency compared with the registry. The most common discrepancy was the timing of the assessment (ie, follow-up period) reported in the publication vs. the registry. DISCUSSION: Although JSES recommends prospective trial registration, less than half of shoulder arthroplasty RCTs are registered and more than 30% registered trials have at least 1 inconsistency with their registry record. More rigorous review of trial registration and accuracy is necessary to limit bias in published shoulder arthroplasty RCTs.

Pediatric Shoulder Arthroscopy Case Volume Is Uniformly Low for Graduating Orthopaedic Residents.

Purpose: To evaluate shoulder arthroscopy case volume for graduating United States orthopaedic surgery residents. Methods: We used the Accreditation Council for Graduate Medical Education case log records to evaluate reports from academic years 2016 to 2020. Logs were queried for pediatric, adult, and total (pediatric and adult) cases. The 10th, 30th, 50th, and 90th percentiles of case volumes from 2016 to 2020 were presented to demonstrate case volume variability. Results: There was a significant increase in the average number of total (70.7 ± 35 vs 81.8 ± 45; P < .001), adult (69 ± 34 vs 79.7 ± 44; P < .001), and pediatric (1.8 ± 2 vs 2.2 ± 3; P = .003) shoulder arthroscopy cases performed by orthopaedic surgery residents between the academic year 2016 and 2020. Residents were involved in more than 36 times the number of adult cases compared with pediatric cases in 2020 (79.7 ± 44 vs 2.2 ± 3; P < .001). The 90th percentile of residents performed 6 pediatric cases in 2020, compared with zero cases in the 30th percentile and lower. Conclusions: Approximately one-third of orthopedic surgery residents graduate without having performed a pediatric shoulder arthroscopy. Clinical Relevance: The findings from this study could help guide the revision of current Accreditation Council for Graduate Medical Education guidelines for orthopaedic surgery residents.

Risks of Immunosuppressive Therapy in Patients Undergoing Open Reduction Internal Fixation for Ankle Fractures.

Chronic steroid and immunosuppressant use have been shown to increase the risk for postoperative complications in orthopedic surgery. Further understanding of the risks of immunosuppression is necessary to aid in risk stratification and patient counseling. However, these risks have not yet been explored in ankle fracture patients. Thus, the purpose of this study is to determine whether patients taking immunosuppressives are at an increased risk for morbidity and mortality following open reduction and internal fixation (ORIF) of ankle fractures. Patients undergoing operative treatment for ankle fractures from 2006 to 2018 were identified in the National Surgical Quality Improvement Program database. Patients were categorized based on their use of immunosuppressive medications. Postoperative outcomes assessed included superficial surgical site infections, deep surgical site infections, organ space infections, wound dehiscence, pneumonia, unplanned intubation, pulmonary embolism, urinary tract infection, renal failure, blood transfusion requirement, deep vein thrombosis, sepsis, cardiac arrest, extended length of hospital stay, readmission, reoperation, and mortality. Univariate and multivariate analyses were performed. In total, 10,331 patients underwent operative treatment for ankle fracture. Total 10,153 patients (98.3%) were not taking immunosuppressants and 178 (1.7%) were taking these medications. In multivariate analysis, patients taking immunosuppressants were at increased risk of pulmonary embolism (odds ratio [OR] 4.382; p = .041) and hospital readmission (OR 2.131; p = .021). Use of immunosuppressive medications is an independent risk factor for pulmonary embolism and readmission following ORIF for ankle fractures. Notably, no association with wound complications, infections, or sepsis was identified.

Pediatric Shoulder Arthroscopy is Effective and Most Commonly Indicated for Instability, Obstetric Brachial Plexus Palsy, and Partial Rotator Cuff Tears.

Purpose: The purpose of this review was to systematically evaluate the literature on pediatric shoulder arthroscopy and outline its indications, outcomes, and complications. Methods: This systematic review was carried out in accordance with PRISMA guidelines. PubMed, Cochrane Library, ScienceDirect, and OVID Medline were searched for studies reporting the indications, outcomes, or complications in patients undergoing shoulder arthroscopy under the age of 18 years. Reviews, case reports, and letters to the editor were excluded. Data extracted included surgical techniques, indications, preoperative and postoperative functional and radiographic outcomes, and complications. The methodological quality of included studies was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) tool. Results: Eighteen studies, with a mean MINORS score of 11.4/16, were identified, including a total of 761 shoulders (754 patients). Weighted average age was 13.6 years (range, 0.83-18.8 years) with a mean follow-up time of 34.6 months (range, 6-115). As part of their inclusion criteria, 6 studies (230 patients) recruited patients with anterior shoulder instability and 3 studies recruited patients with posterior shoulder instability (80 patients). Other indications for shoulder arthroscopy included obstetric brachial plexus palsy (157 patients) and rotator cuff tears (30 patients). Studies reported a significant improvement in functional outcomes for arthroscopy indicated for shoulder instability and obstetric brachial plexus palsy. A significant improvement was also noted in radiographic outcomes and range of motion for obstetric brachial plexus palsy patients. The overall rate of complication ranged from 0% to 25%, with 2 studies reporting no complications. The most common complication was recurrent instability (38 patients of 228 [16.7%]). Fourteen of the 38 patients (36.8%) underwent reoperation. Conclusion: Among pediatric patients, shoulder arthroscopy was indicated most commonly for instability, followed by brachial plexus birth palsy, and partial rotator cuff tears. Its use resulted in good clinical and radiographic outcomes with limited complications. Level of Evidence: Systematic review of Level II to IV studies.

The Relative Citation Ratio: Evaluating a New Measure of Scientific Influence Among Academic Sports Medicine Surgeons.

Background: Objective measures of research influence are being increasingly utilized to evaluate and compare academic faculty. However, traditional bibliometrics, such as the Hirsch index and article citation count, are biased by time-dependent factors and are limited by a lack of field normalization. The relative citation ratio (RCR) is a new field- and time-normalized article-level metric developed by the National Institutes of Health (NIH). Purpose/Hypothesis: The purpose of this study was to evaluate the RCR among fellowship-trained academic sports medicine surgeons and to analyze physician factors associated with RCR values. We hypothesized that the mean RCR score for fellowship-trained academic sports medicine surgery faculty will fall above the NIH standard. Study Design: Cross-sectional study. Methods: A retrospective data analysis was performed using the iCite database for all fellowship-trained sports medicine surgery faculty associated with Accreditation Council for Graduate Medical Education-accredited orthopaedic surgery residency programs in December 2021. In eligible faculty, the mean RCR, weighted RCR, and total publication count were compared by sex, career duration, academic rank, and presence of additional degrees. A mean RCR value of 1.0 is the NIH-funded field-normalized standard. The data herein are presented as the median and interquartile range, in addition to the mean and standard deviation, to account for outliers of the mean and weighted RCR scores. Results: A total of 624 fellowship-trained sports medicine surgery faculty members from 160 orthopaedic surgery residency programs were included in the analysis. Overall, faculty produced impactful research, with a median RCR of 1.6 (interquartile range, 1.0-2.2) and a median weighted RCR of 19.3 (interquartile range, 5.1-69.3). Advanced academic rank and career longevity were associated with increased weighted RCR and total publication count. All subgroups analyzed had an RCR value >1.0. Conclusion: Study findings indicate that fellowship-trained academic sports medicine surgery faculty are highly productive and produce impactful research, as evidenced by the high median RCR value relative to the benchmark NIH RCR value of 1.0.

Bayesian Calibration of Computational Knee Models to Estimate Subject-Specific Ligament Properties, Tibiofemoral Kinematics, and Anterior Cruciate Ligament Force With Uncertainty Quantification.

High-grade knee laxity is associated with early anterior cruciate ligament (ACL) graft failure, poor function, and compromised clinical outcome. Yet, the specific ligaments and ligament properties driving knee laxity remain poorly understood. We described a Bayesian calibration methodology for predicting unknown ligament properties in a computational knee model. Then, we applied the method to estimate unknown ligament properties with uncertainty bounds using tibiofemoral kinematics and ACL force measurements from two cadaver knees that spanned a range of laxities; these knees were tested using a robotic manipulator. The unknown ligament properties were from the Bayesian set of plausible ligament properties, as specified by their posterior distribution. Finally, we developed a calibrated predictor of tibiofemoral kinematics and ACL force with their own uncertainty bounds. The calibrated predictor was developed by first collecting the posterior draws of the kinematics and ACL force that are induced by the posterior draws of the ligament properties and model parameters. Bayesian calibration identified unique ligament slack lengths for the two knee models and produced ACL force and kinematic predictions that were closer to the corresponding in vitro measurement than those from a standard optimization technique. This Bayesian framework quantifies uncertainty in both ligament properties and model outputs; an important step towards developing subject-specific computational models to improve treatment for ACL injury.

A Systematic Review of Lower-Body Kinematic and Strength Factors Associated With Pitch Velocity in Adult Baseball Pitchers.

CONTEXT: Ball velocity for baseball pitchers is influenced by a multitude of factors along the kinetic chain. While a vast amount of data currently exist exploring lower-extremity kinematic and strength factors in baseball pitchers, no previous study has systematically reviewed the available literature. OBJECTIVE: The aim of this systematic review was to perform a comprehensive assessment of the available literature investigating the association between lower-extremity kinematic and strength parameters and pitch velocity in adult pitchers. EVIDENCE ACQUISITION: Cross-sectional studies that investigated the association between lower-body kinematic and strength factors and ball velocity in adult pitchers were selected. A methodological index for nonrandomized studies checklist was used to evaluate the quality of all included studies. EVIDENCE SYNTHESIS: Seventeen studies met the inclusion criteria comprising a total of 909 pitchers (65%, professional, 33% college, and 3% recreational). The most studied elements were hip strength and stride length. The mean methodological index for nonrandomized studies score was 11.75 of 16 (range = 10-14). Pitch velocity was found to be influenced by several lower-body kinematic and strength factors including the following: (1) hip range of motion and strength of muscles around the hip and pelvis, (2) alterations in stride length, (3) alterations in lead knee flexion/extension, and (4) several pelvic and trunk spatial relationships throughout the throwing phase. CONCLUSIONS: Based on this review, we conclude that hip strength is a well-established predictor of increased pitch velocity in adult pitchers. Further studies in adult pitchers are needed to elucidate the effect of stride length on pitch velocity given mixed results across multiple studies. This study can provide a basis for trainers and coaches to consider the importance of lower-extremity muscle strengthening as a means by which adult pitchers can improve pitching performance.