Cross-sectional areas of rotator cuff muscles in males without tears on shoulder MRI.

OBJECTIVE: To establish reference values of rotator cuff (RC) cross sectional area (CSA) in males. MATERIALS AND METHODS: We retrospectively analyzed shoulder MRIs from 500 patients aged 13-78 years, grouped as follows (N=100 in each): <20, 20-30, 30-40, 40-50, >50 years. All examinations were reviewed to exclude prior surgery, tears, or significant RC pathology. We segmented a standardized T1 sagittal MR image in each case to obtain CSA of supraspinatus (SUP), infraspinatus/teres minor (INF), and subscapularis (SUB) muscles. Across age groups, we recorded individual and total muscle CSA. We also performed ratios between individual muscle CSA and total CSA to examine total muscle mass contribution over age groups. We tested for differences between age groups controlled for BMI. RESULTS: CSAs for SUP, INF, SUB, and total RC CSA were lower in subjects >50 years compared to all other groups (P<0.003 for all comparisons), persisting after controlling for BMI (P<0.03). Relative contribution of SUP CSA to total RC CSA was stable across age groups (P>0.32). INF CSA relative to total RC CSA increased with age, whereas SUB decreased (P<0.005). Subjects >50 years showed lower SUP (-15%), INF (-6%), and SUB (-21%) CSA, when compared to mean CSAs of all subjects <50 years. Total RC CSA significantly correlated with age (r=-0.34, P<0.001), persisting after controlling for BMI (r=-0.42, P<0.001). CONCLUSION: RC muscles in male subjects with no tears on MRI show decreasing CSA with age, independent of BMI.

Distal Triceps Tendon Tears: Magnetic Resonance Imaging Patterns Using a Systematic Classification.

OBJECTIVE: This study aimed to evaluate distal triceps tendon tear patterns using a systematic classification based on the tendon's layered structure. METHODS: We retrospectively identified Magnetic resonance imaging (MRI) examinations with triceps tendon tears that underwent reconstructive surgery. Magnetic resonance images were reviewed independently by 2 musculoskeletal radiologists to determine tendon layer involvement and ancillary findings, including tear size, involvement of triceps lateral expansion, and presence of olecranon bursal fluid. Surgical reports were scrutinized for level of anatomic detail and correlation with imaging findings. RESULTS: We identified 69 triceps tendon tears in 68 subjects (61 men, 7 women; mean age, 45 ± 12 years) who underwent surgical reconstruction. On MRI, the superficial layer was always involved with either a partial or full-thickness tear. The most common tear pattern was a combination of superficial layer full-thickness tear with deep layer partial tear (25 of 69 [36%]). Mean tear length was 24 ± 12 mm. We found no cases of isolated deep layer tears. Involvement of triceps lateral expansion and presence of bursal fluid correlated positively with tear severity of superficial and deep layers (P < 0.001). Detailed surgical correlation was limited, with only 9 of 69 (13%) of surgical reports containing information specifically addressing individual tendon layers. CONCLUSIONS: Triceps tendon tears show tear patterns following its layered structure and can be assessed by MRI. Radiologists and surgeons are encouraged to describe tear patterns considering both superficial and deep tendon layers.

Biological augmentation of meniscal repair: a systematic review.

PURPOSE: Orthopedic literature remains divided on the utility of biologic augmentation to optimize outcomes after isolated meniscal repair. The aim of this systematic review is to analyze the clinical outcomes and re-operation rates of biologically augmented meniscal repairs. METHODS: PubMed, CINAHL, Cochrane, and EMBASE databases were queried in October 2020 for published literature on isolated meniscal repair with biological augmentation. Studies were assessed for quality and risk of bias by two appraisal tools. Patient demographics, meniscal tear characteristics, surgical procedure, augmentation type, post-operative rehabilitation, patient reported outcome measures, and length of follow-up were recorded, reviewed, and analyzed by two independent reviewers. RESULTS: Of 3794 articles, 18 met inclusion criteria and yielded 537 patients who underwent biologic augmentation of meniscal repair. The biologically augmented repair rates were 5.8-27.0% with PRP augmentation, 0.0-28.5% with fibrin clot augmentation, 0.0-12.9% with marrow stimulation, and 0.0% with stem cell augmentation. One of seven studies showed lower revision rates with augmented meniscal repair compared to standard repair techniques, whereas five of seven found no benefit. Three of ten studies found significant functional improvement of biologically augmented repair versus standard repair techniques and six of ten studies found no difference. There was significant heterogeneity in methods for biologic preparation, delivery, and post-operative rehabilitation protocols. CONCLUSION: Patients reported significant improvements in functional outcomes scores after repair with biological augmentation, though the benefit over standard repair controls is questionable. Revision rates after biologically augmented meniscal repair also appear similar to standard repair techniques. Clinicians should bear this in mind when considering biologic augmentation in the setting of meniscal repair. LEVEL OF EVIDENCE: IV.

Change in humeral anchor position significantly affects isometry in ulnar collateral ligament repair: a 3-dimensional computer modeling study.

BACKGROUND: Medial ulnar collateral ligament (UCL) repair utilization is increasing in recent years, bolstered by shorter rehabilitation and satisfactory clinical outcomes. Although previous literature has illustrated the importance of tunnel position on restoring graft isometry in reconstruction, there remains a paucity of literature guiding anchor placement in UCL repair. The purpose of this study is to design a 3-dimensional (3D) elbow model to understand the effect of anchor location on UCL repair isometry. METHODS: A 3D computer model of an elbow joint was created using computed tomographic and magnetic resonance imaging MRI scans from a single patient. The humeral and ulnar attachments of the UCL were plotted using 3 methodologies: (1) geometric cloud mapping and (2) quantitative measurements from the anatomic studies by Camp et al and (3) Frangiamore et al. A 3.5-mm-diameter clockface was placed on each attachment site, which allowed for simulation of 12 distinct 1.75-mm deviations in anchor position. The 3 models were ranged through 0°-120° at 10° increments, and the 3D distances were measured between the ligament centroids. The humeral and ulnar anchors were sequentially repositioned around the clockfaces, and construct lengths were again measured to evaluate changes in isometry. A paired Student t test was performed to determine if there was a significant difference in isometry between the humeral and ulnar anchor deviations. RESULTS: Using method 1, the UCL repair length at 90° of elbow flexion was 26.8 mm. This construct underwent 13.6 mm of total excursion for a 46.4% change in length throughout its arc of motion. Method 2 produced a 19.3-mm construct that underwent 0.8 mm of excursion for a 3.9% length change throughout the arc. Method 3 produced a 24.5-mm construct that underwent 2.3 mm of excursion for a 9.4% length change. Identifying ligament footprints using the quantitative anatomic measurements from Camp et al and Frangiamore et al improved construct isometry through 120° of flexion (length changes of 3.9% and 9.4%, respectively) when compared to using the geometric cloud technique alone (46.4% length change). Humeral anchor deviations produced a significant increase in repair construct excursion compared with ulnar anchor deviations (P < .001). CONCLUSION: When performing UCL repair, small deviations in humeral anchor position may significantly influence ligament repair isometry. Using quantitative anatomic data may help identify anchor positions with improved repair isometry. Particularly when addressing detachments of the humeral footprint, surgeons should be critical of the humeral anchor position in order to restore native anatomy and optimal biomechanics.

Deep learning method for segmentation of rotator cuff muscles on MR images.

OBJECTIVE: To develop and validate a deep convolutional neural network (CNN) method capable of (1) selecting a specific shoulder sagittal MR image (Y-view) and (2) automatically segmenting rotator cuff (RC) muscles on a Y-view. We hypothesized a CNN approach can accurately perform both tasks compared with manual reference standards. MATERIAL AND METHODS: We created 2 models: model A for Y-view selection and model B for muscle segmentation. For model A, we manually selected shoulder sagittal T1 Y-views from 258 cases as ground truth to train a classification CNN (Keras/Tensorflow, Inception v3, 16 batch, 100 epochs, dropout 0.2, learning rate 0.001, RMSprop). A top-3 success rate evaluated model A on 100 internal and 50 external test cases. For model B, we manually segmented subscapularis, supraspinatus, and infraspinatus/teres minor on 1048 sagittal T1 Y-views. After histogram equalization and data augmentation, the model was trained from scratch (U-Net, 8 batch, 50 epochs, dropout 0.25, learning rate 0.0001, softmax). Dice (F1) score determined segmentation accuracy on 105 internal and 50 external test images. RESULTS: Model A showed top-3 accuracy > 98% to select an appropriate Y-view. Model B produced accurate RC muscle segmentations with mean Dice scores > 0.93. Individual muscle Dice scores on internal/external datasets were as follows: subscapularis 0.96/0.93, supraspinatus 0.97/0.96, and infraspinatus/teres minor 0.97/0.95. CONCLUSIONS: Our results show overall accurate Y-view selection and automated RC muscle segmentation using a combination of deep CNN algorithms.

Rehabilitation variability after rotator cuff repair.

BACKGROUND: There has been increasing recognition of the importance for standardized postoperative rehabilitation protocols. Despite published guidelines in 2016 by the American Society of Shoulder and Elbow Therapists (ASSET), optimal postoperative rehabilitation after rotator cuff repair (RCR) remains an area of active academic debate. The goals of this study were (1) to assess the variability of RCR rehabilitation protocols published online, (2) to study the congruence between online RCR rehabilitation protocols and the ASSET consensus statement, and (3) to identify differences in online RCR rehabilitation protocols from before and after 2016. METHODS: A web-based search was conducted for publicly available RCR rehabilitation protocols from websites of all Accreditation Council for Graduate Medical Education (ACGME) academic orthopedic institutions. A supplemental 10-page Google search was also performed with the search terms "rotator cuff repair rehabilitation protocol." Collected protocols were grouped by tear size (small/medium or large/massive) and examined for information relating to the following categories: protocol demographics, adjunctive therapy use, immobilization/range of motion, and strengthening. Findings were compared to the ASSET statement's recommendations. Protocols published before and after ASSET's 2016 publication were compared for differences. RESULTS: A total of 66 online RCR rehabilitation protocols were collected. Only 16 of 187 (8.5%) ACGME institutions provided online RCR rehabilitation protocols. The collected protocols recommend more aggressive rehabilitation in comparison to ASSET, specifically regarding immobilization time, passive range of motion initiation, active assisted range of motion initiation, and strengthening initiation (P < .001). Protocols published after 2016 trended toward more conservative recommendations in comparison to protocols published before 2016. Regardless of this trend, the majority of these recommendations were still largely more aggressive than ASSET's recommendations. CONCLUSION: Despite an attempt by ASSET to provide standardization, this study highlights the marked variations that still exist regarding RCR rehabilitation. Additionally, online RCR rehabilitation protocols tend to make more aggressive recommendations than the ASSET consensus statement. Further research is needed to address these variations and to either validate, alter, or reject the ASSET recommendations.

The Association of Baseball Pitch Delivery and Kinematic Sequence on Stresses at the Shoulder and Elbow Joints.

Although there is a commonly held belief within the baseball community that delivery from the stretch confers more stress at the elbow and shoulder joints than delivery from the windup, there remains little evidence in the literature investigating this hypothesis. This study aimed to help address this gap in the literature by studying both intra-pitcher kinematic sequence variability, and intra-pitcher joint torque variability when throwing from the windup vs. the stretch. We hypothesized that 1) each pitchers' kinematic sequence would remain similar whether throwing from the windup or stretch, and 2) Kinematic sequence would influence peak arm torque more than delivery method. This cross-sectional 3D biomechanical study included 88 pitches thrown by ten (6 collegiate, 4 high school) pitchers with a mean age of 17.60 ± 2.63 years. Pitch velocity, throwing shoulder/elbow torques and the kinematic sequence of each pitch utilizing segmental peak angular velocities were captured. No statistically significant differences in ball velocity (p = 0.17), peak shoulder external rotation torque (p = 0.80), shoulder extension torque (p = 0.97), or elbow valgus torque (p = 0.83) were found between delivery approaches. Three primary kinematic sequences were identified. Shoulder external rotation torque [F(53,2) = 10.992, ɳ2 = .293, p < 0.00], shoulder extension torque [F(53,2) = 15.517, ɳ2 = .369, p < 0.00] and elbow valgus torque [F(53,2) = 9.994, ɳ2 = .274, p < 0.00] did vary significantly across these three kinematic sequence patterns. Our data suggest that the kinematic sequence influences shoulder and elbow torque more than the delivery approach. Instructing ideal kinematic sequence may be more influential for injury avoidance than delivery method.

Interferon-gamma production in Lyme arthritis synovial tissue promotes differentiation of fibroblast-like synoviocytes into immune effector cells.

Lyme arthritis (LA), a late disease manifestation of Borrelia burgdorferi infection, usually resolves with antibiotic therapy. However, some patients develop proliferative synovitis lasting months to several years after spirochetal killing, called postinfectious LA. In this study, we phenotyped haematopoietic and stromal cell populations in the synovial lesion ex vivo and used these findings to generate an in vitro model of LA using patient-derived fibroblast-like synoviocytes (FLS). Ex vivo analysis of synovial tissue revealed high abundance of IFNγ-producing T cells and NK cells. Similar to marked IFNγ responses in tissue, postinfectious LA synovial fluid also had high levels of IFNγ. HLA-DR-positive FLS were present throughout the synovial lesion, particularly in areas of inflammation. FLS stimulated in vitro with B. burgdorferi, which were similar to conditions during infection, expressed 68 genes associated primarily with innate immune activation and neutrophil recruitment. In contrast, FLS stimulated with IFNγ, which were similar to conditions in the postinfectious phase, expressed >2,000 genes associated with pathogen sensing, inflammation, and MHC Class II antigen presentation, similar to the expression profile in postinfectious synovial tissue. Furthermore, costimulation of FLS with B. burgdorferi and IFNγ induced greater expression of IL-6 and other innate immune response proteins and genes than with IFNγ stimulation alone. These results suggest that B. burgdorferi infection, in combination with IFNγ, initiates the differentiation of FLS into a highly inflammatory phenotype. We hypothesise that overexpression of IFNγ by lymphocytes within synovia perpetuates these responses in the postinfectious period, causing proliferative synovitis and stalling appropriate repair of damaged tissue.

Injured vs. uninjured elbow opening on clinical stress radiographs and its relationship to ulnar collateral ligament injury severity in throwers.

BACKGROUND: Stress radiography measures medial joint space opening of the elbow, but its value in the management of throwing athletes is unclear. The purpose of this study was to analyze the relationship between medial joint opening (gapping and excess opening) and ulnar collateral ligament (UCL) injury severity on magnetic resonance imaging, as well as to explore factors related to the unexpected finding of a greater opening of the uninjured elbow compared with the injured elbow (negative excess opening) with valgus stress radiography. METHODS: Medial joint space measurements were independently performed by 2 raters in a clinical series of 74 patients evaluated with standardized valgus stress radiography as part of their clinical workup for throwing-related medial elbow pain. Demographic data were collected by chart review, and UCL injury severity was classified based on available imaging into intact UCLs, partial-thickness tears of the anterior bundle, or full-thickness tears of the anterior bundle. RESULTS: Joint gapping was related to UCL injury severity (P = .003), and group-level comparison showed a difference among tear severity groups (P = .050). Excess opening was not significantly related to UCL injury severity (P = .109). A negative excess opening was observed in 22% of patients, but no factors corroborating guarding or a mechanical explanation were significant for a decreased medial joint opening of the injured elbow compared with the uninjured elbow. CONCLUSIONS: Medial joint gapping was correlated to UCL injury severity in throwing athletes with medial elbow pain and a clinical suggestion of UCL injury, but no association between injury severity and excess opening was observed in this clinical series, which may limit the usefulness of stress radiography in the clinical workup of throwing athletes.

Paget-Schroetter syndrome in athletes: a comprehensive and systematic review.

BACKGROUND: Paget-Schroetter syndrome (PSS) is a rare condition of axillosubclavian vein thrombosis often seen in athletes with a history of repetitive external rotation and abduction of the shoulder. The purpose of this review was to analyze the literature and characterize PSS in the athletic population, including risk of PSS by sport. We also provide a comprehensive review of PSS to inform clinicians on the pathophysiology, detection, and management of the condition. METHODS: Four databases were reviewed to identify cases of PSS occurring in athletes. Data on patient demographics, reported sport, diagnosis, treatment, management, return to sport, and complications were extracted and analyzed by 2 independent reviewers. RESULTS: Of the 123 cases of PSS identified, baseball and weight lifting had the highest incidence (26.8% and 19%, respectively), followed by swimming, football, and basketball. The average return to sport was 4.7 months, and 26.7% of subjects reported complications, most commonly pulmonary embolism. CONCLUSION: In athletes presenting with upper extremity pain and swelling with a history of playing baseball or weight lifting, PSS should be higher on a clinicians differential diagnosis list. Swimmers, football, and basketball players are less likely to present with PSS but are still more likely than other types of athletes to develop the condition. Clinician awareness of PSS in athletes is critical to avoid delays in treatment and misdiagnosis, and to allow for a timely return to sport with minimal complications.

Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA). Objective: To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions. Design, Setting, and Participants: Randomized clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) was conducted in 48 healthy participants. The study was conducted between January and February 2019. Interventions: Participants were randomized to 1 of 4 sunscreen products, formulated as lotion (n = 12), aerosol spray (n = 12), nonaerosol spray (n = 12), and pump spray (n = 12). Sunscreen product was applied at 2 mg/cm2 to 75% of body surface area at 0 hours on day 1 and 4 times on day 2 through day 4 at 2-hour intervals, and 34 blood samples were collected over 21 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone over days 1 through 21. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, homosalate, octisalate, and octinoxate over days 1 through 21. Results: Among 48 randomized participants (mean [SD] age, 38.7 [13.2] years; 24 women [50%]; 23 white [48%], 23 African American [48%], 1 Asian [2%], and 1 of unknown race/ethnicity [2%]), 44 (92%) completed the trial. Geometric mean maximum plasma concentrations of all 6 active ingredients were greater than 0.5 ng/mL, and this threshold was surpassed on day 1 after a single application for all active ingredients. For avobenzone, the overall maximum plasma concentrations were 7.1 ng/mL (coefficient of variation [CV], 73.9%) for lotion, 3.5 ng/mL (CV, 70.9%) for aerosol spray, 3.5 ng/mL (CV, 73.0%) for nonaerosol spray, and 3.3 ng/mL (CV, 47.8%) for pump spray. For oxybenzone, the concentrations were 258.1 ng/mL (CV, 53.0%) for lotion and 180.1 ng/mL (CV, 57.3%) for aerosol spray. For octocrylene, the concentrations were 7.8 ng/mL (CV, 87.1%) for lotion, 6.6 ng/mL (CV, 78.1%) for aerosol spray, and 6.6 ng/mL (CV, 103.9%) for nonaerosol spray. For homosalate, concentrations were 23.1 ng/mL (CV, 68.0%) for aerosol spray, 17.9 ng/mL (CV, 61.7%) for nonaerosol spray, and 13.9 ng/mL (CV, 70.2%) for pump spray. For octisalate, concentrations were 5.1 ng/mL (CV, 81.6%) for aerosol spray, 5.8 ng/mL (CV, 77.4%) for nonaerosol spray, and 4.6 ng/mL (CV, 97.6%) for pump spray. For octinoxate, concentrations were 7.9 ng/mL (CV, 86.5%) for nonaerosol spray and 5.2 ng/mL (CV, 68.2%) for pump spray. The most common adverse event was rash, which developed in 14 participants. Conclusions and Relevance: In this study conducted in a clinical pharmacology unit and examining sunscreen application among healthy participants, all 6 of the tested active ingredients administered in 4 different sunscreen formulations were systemically absorbed and had plasma concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. These findings do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

What are the Implications of Excessive Internet Searches for Medical Information by Orthopaedic Patients?

BACKGROUND: Cyberchondria may be defined as heightened distress evoked through excessive searches of the internet for medical information. In healthy people, cyberchondria is associated with a greater intolerance of uncertainty and greater health anxiety. These relationships are likely bidirectional. People who have a greater intolerance of uncertainty may be more likely to search the internet for medical information and have greater health anxiety. This greater health anxiety may lead to an increased likelihood of engaging in further internet searches and greater intolerance of uncertainty. These three constructs are important for patients because they impact patient function and health care costs. We were specifically interested in understanding the role of cyberchondria in the association between intolerance of uncertainty and health anxiety among orthopaedic patients because it has not been explored before and because knowledge about these interactions could inform treatment recommendations. QUESTIONS/PURPOSES: Does cyberchondria mediate (that is, explain) the association between intolerance of uncertainty and health anxiety in orthopaedic patients searching for medical information on the internet, after controlling for potentially confounding variables? METHODS: This was a cross-sectional study of 104 patients who had searched the internet for any medical information about their current condition. A research assistant approached 155 patients attending two orthopaedic outpatient clinics, one hand and upper extremity service and one sports medicine clinic, during a 3-month period. Ten patients declined to participate and 41 patients were excluded, predominantly because they had never searched for medical information online. The patients completed the Cyberchondria Severity Scale, Intolerance of Uncertainty Scale-short version, Short Health Anxiety Inventory, and a numerical rating scale for pain intensity at baseline, as well as demographic and clinical questionnaires. We performed a series of linear regression analyses to determine whether a greater intolerance of uncertainty predicts greater cyberchondria (mediator) and whether cyberchondria predicts greater health anxiety. Although it is more appropriate to use the language of association (such as "whether cyberchondria is associated with health anxiety") in many observational studies, here, we opted to use the language of causation because this is the conventional language for studies testing statistical mediation. RESULTS: After controlling for potentially confounding variables including pain intensity, multiple pain conditions, and education, cyberchondria explained 33% of the variance of the effect of intolerance of uncertainty on health anxiety (95% CI, 6.98 to 114.72%; p < 0.001). CONCLUSIONS: Among orthopaedic patients who search the internet for medical information, a greater intolerance of uncertainty is associated with greater cyberchondria, which is associated with greater anxiety about health. Identifying patients with an intolerance of uncertainty and educating them about the negative role of compulsive searches for medical information may improve the success of orthopaedic treatment. Orthopaedic surgeons should also consider making referrals for cognitive behavioral therapy in these instances to increase the patient's tolerance of uncertainty, decrease internet searching habits, and reduce anxiety about health. LEVEL OF EVIDENCE: Level III, prognostic study.

Locating the ulnar nerve during elbow arthroscopy using palpation is only accurate proximal to the medial epicondyle.

PURPOSE: Knowledge of ulnar nerve position is of utmost importance to avoid iatrogenic injury in elbow arthroscopy. The aim of this study was to determine how accurate surgeons are in locating the ulnar nerve after fluid extravasation has already occurred, and basing their localization solely on palpation of anatomical landmarks. METHODS: Seven cadaveric elbows were used and seven experienced surgeons in elbow arthroscopy participated. An arthroscopic setting was simulated and fluids were pumped into the joint from the posterior compartment for 15 min. For each cadaveric elbow, one surgeon was asked to locate the ulnar nerve solely by palpation of the anatomical landmarks, and subsequently pin the ulnar nerve at two positions: within 5 cm proximal and another within 5 cm distal of a line connecting the medial epicondyle and the tip of the olecranon. Subsequently, the elbows were dissected using a standard medial elbow approach and the distances between the pins and ulnar nerve were measured. RESULTS: The median distance between the ulnar nerve and the proximal pins was 0 mm (range 0-0 mm), and between the ulnar nerve and the distal pins was 2 mm (range 0-10 mm), showing a statistically significant difference (p = 0.009). All seven proximally placed pins (100%) transfixed the ulnar nerve versus two out of seven distally placed pins (29%) (p = 0.021). CONCLUSIONS: In a setting simulating an already initiated arthroscopic procedure, the sole palpation of the anatomical landmarks allows experienced elbow surgeons to accurately locate the ulnar nerve only in its course proximal to the medial epicondyle (7/7, 100%), whereas a significantly reduced accuracy is documented when the same surgeons attempt to locate the nerve distal to the medial epicondyle (2/7, 29%; p = 0.021). Current findings support the establishment of a proximal anteromedial portal over a distal anteromedial portal to access the anterior compartment after tissue extravasation has occurred with regard to ulnar nerve safety.

The pathoanatomy of the anterior bundle of the medial ulnar collateral ligament.

BACKGROUND: The purpose of this study was to increase our understanding of the pathoanatomy of the ulnar collateral ligament (UCL) by performing a descriptive analysis of the surgical inspection of the anterior bundle in patients undergoing reconstruction. METHODS: A single-surgeon series of 163 patients who underwent UCL reconstruction between 2009 and 2017 was retrospectively analyzed. Descriptions of the pathoanatomy of injury were obtained from the operative reports. Magnetic resonance imaging data were reviewed to assess whether the presence and location of tissue disruptions were accurately recognized. Demographic and clinical characteristics were obtained from medical records and correlated to observed pathoanatomy. RESULTS: Injuries to the anterior bundle were characterized by a single tissue disruption (65%), tissue disruptions at more than 1 location (23%), or injuries without distinct fiber tissue disruptions (12%). The presence and location of tissue disruptions matched magnetic resonance imaging findings in 124 of 153 patients (81%). Partial tears more frequently affected the anterior band of the anterior bundle distally as opposed to the posterior band of the anterior bundle proximally (P = .012). Patients with single tissue disruptions more frequently reported a popping sensation than patients with non-tear insufficiency (P = .030). CONCLUSIONS: This study shows the heterogeneity of anterior bundle injuries in patients undergoing UCL reconstruction. A variety of injury configurations and chronic attritional damage to the anterior bundle were observed, as well as distinct tear patterns at the distal and proximal attachment sites. Future research may elucidate the diagnostic value of a pop sign for UCL injury.

The relationship of elbow alignment and kinematics on shoulder torque during the softball pitch: a biomechanical analysis of female softball pitchers.

BACKGROUND: Female softball pitchers commonly throw more pitches per game and season than their baseball counterparts. The greatest stress to the shoulder during a softball windmill pitch is at ball release (BR). This study investigated shoulder torques at BR among female softball pitchers and identified relationships to the kinematics of the elbow and forearm and alignment of the elbow (carrying angle and elbow extension). METHODS: High-speed 3-dimensional biomechanical analyses were performed in 33 pitchers (25 high school, 8 collegiate). Elbow and shoulder biomechanics at BR during fastball pitches and goniometric measures of carrying angle and elbow extension were collected and analyzed. RESULTS: Carrying angle correlated positively with shoulder extension torque at BR (rs = 0.371, P = .048) and forearm pronation at BR (rs = 0.370, P = .048). During the windmill pitch, the greater the elbow flexion, the greater shoulder adduction torque at BR (rs = -0.522, P = .007). Multiple regression analysis revealed that the carrying angle, passive elbow extension, and elbow flexion/extension angle at BR predicted shoulder flexion/extension torque at BR (F3,24 = 3.463, R2 = .302, P = .032.) CONCLUSIONS: Our findings demonstrate that shoulder torques during the softball fastpitch are influenced by the carrying angle and the kinematic elbow flexion angle at BR. Sports medicine clinicians and coaches should consider the role that the elbow carrying angle plays in creating shoulder stress when treating and training fastpitch softball players.

Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies. Objective: To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation. Design, Setting, and Participants: Randomized clinical trial conducted at a phase 1 clinical pharmacology unit in the United States and enrolling 24 healthy volunteers. Enrollment started in July 2018 and ended in August 2018. Interventions: Participants were randomized to 1 of 4 sunscreens: spray 1 (n = 6 participants), spray 2 (n = 6), a lotion (n = 6), and a cream (n = 6). Two milligrams of sunscreen per 1 cm2 was applied to 75% of body surface area 4 times per day for 4 days, and 30 blood samples were collected over 7 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, and ecamsule. Results: Among 24 participants randomized (mean age, 35.5 [SD, 1.5] years; 12 (50%] women; 14 [58%] black or African American; 14 [58%]), 23 (96%) completed the trial. For avobenzone, geometric mean maximum plasma concentrations were 4.0 ng/mL (coefficient of variation, 6.9%) for spray 1; 3.4 ng/mL (coefficient of variation, 77.3%) for spray 2; 4.3 ng/mL (coefficient of variation, 46.1%) for lotion; and 1.8 ng/mL (coefficient of variation, 32.1%). For oxybenzone, the corresponding values were 209.6 ng/mL (66.8%) for spray 1, 194.9 ng/mL (52.4%) for spray 2, and 169.3 ng/mL (44.5%) for lotion; for octocrylene, 2.9 ng/mL (102%) for spray 1, 7.8 ng/mL (113.3%) for spray 2, 5.7 ng/mL (66.3%) for lotion, and 5.7 ng/mL (47.1%) for cream; and for ecamsule, 1.5 ng/mL (166.1%) for cream. Systemic concentrations greater than 0.5 ng/mL were reached for all 4 products after 4 applications on day 1. The most common adverse event was rash, which developed in 1 participant with each sunscreen. Conclusions and Relevance: In this preliminary study involving healthy volunteers, application of 4 commercially available sunscreens under maximal use conditions resulted in plasma concentrations that exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens. The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings. These results do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

Do Injured Adolescent Athletes and Their Parents Agree on the Athletes' Level of Psychologic and Physical Functioning?

BACKGROUND: Although a parent's perception of his or her child's physical and emotional functioning may influence the course of the child's medical care, including access to care and decisions regarding treatment options, no studies have investigated whether the perceptions of a parent are concordant with that of an adolescent diagnosed with a sports-related orthopaedic injury. Identifying and understanding the potential discordance in coping and emotional distress within the athlete adolescent-parent dyads are important, because this discordance may have negative effects on adolescents' well-being. QUESTIONS/PURPOSES: The purposes of this study were (1) to compare adolescent and parent proxy ratings of psychologic symptoms (depression and anxiety), coping skills (catastrophic thinking about pain and pain self-efficacy), and upper extremity physical function and mobility in a population of adolescent-parent dyads in which the adolescent had a sport-related injury; and (2) to compare scores of adolescents and parent proxies with normative scores when such are available. METHODS: We enrolled 54 dyads (eg, pairs) of adolescent patients (mean age 16 years; SD = 1.6) presenting to a sports medicine practice with sports-related injuries as well as their accompanying parent(s). We used Patient-reported Outcomes Measurement Information System questionnaires to measure adolescents' depression, anxiety, upper extremity physical function, and mobility. We used the Pain Catastrophizing Scale short form to assess adolescents' catastrophic thinking about pain and the Pain Self-efficacy Scale short form to measure adolescents' pain self-efficacy. The accompanying parent, 69% mothers (37 of 54) and 31% fathers (17 of 54), completed parent proxy versions of each questionnaire. RESULTS: Parents reported that their children had worse scores (47 ± 9) on depression than what the children themselves reported (43 ± 9; mean difference 4.0; 95% confidence interval [CI], -7.0 to 0.91; p = 0.011; medium effect size -0.47). Also, parents reported that their children engaged in catastrophic thinking about pain to a lesser degree (8 ± 5) than what the children themselves reported (13 ± 4; mean difference 4.5; 95% CI, 2.7-6.4; p < 0.001; large effect size 1.2). Because scores on depression and catastrophic thinking were comparable to the general population, and minimal clinically important difference scores are not available for these measures, it is unclear whether the relatively small observed differences between parents' and adolescents' ratings are clinically meaningful. Parents and children were concordant on their reports of the child's upper extremity physical function (patient perception 47 ± 10, parent proxy 47 ± 8, mean difference -0.43, p = 0.70), mobility (patient perception 43 ± 9, parent proxy 44 ± 9, mean difference -0.59, p = 0.64), anxiety (patient perception 43 ± 10, parent proxy 46 ± 8, mean difference -2.1, p = 0.21), and pain self-efficacy (patient perception 16 ± 5, parent proxy 15 ± 5, mean difference 0.70, p = 0.35). CONCLUSIONS: Parents rated their children as more depressed and engaging in less catastrophic thinking about pain than the adolescents rated themselves. Although these differences are statistically significant, they are of a small magnitude making it unclear as to how clinically important they are in practice. We recommend that providers keep in mind that parents may overestimate depressive symptoms and underestimate the catastrophic thinking about pain in their children, probe for these potential differences, and consider how they might impact medical care. LEVEL OF EVIDENCE: Level I, prognostic study.

What Is the Relationship of Fear Avoidance to Physical Function and Pain Intensity in Injured Athletes?

BACKGROUND: Fear avoidance can play a prominent role in maladaptive responses to an injury. In injured athletes, such pain-related fear or fear avoidance behavior may have a substantial influence on the recovery process. Specifically, it may explain why some are able to reach their preinjury abilities, whereas others are unable to return to sport. QUESTIONS/PURPOSES: (1) Is fear avoidance in athletes associated with decreased physical function after injury? (2) To what degree is fear avoidance associated with athletes' pain intensity? METHODS: In a cross-sectional study, we recruited injured athletes-defined as patients with sports-related injury, weekly engagement in sport activities, participation in competitive events as part of a team or club, self-identification as an athlete, and a desire to return to sport after recovery-from an orthopaedic sports medicine center at a major urban university hospital. Of 130 approached patients, 102 (84% men; mean ± SD age 25 ± 8.5 years) met the inclusion criteria. Participants completed a demographic questionnaire, the Athlete Fear Avoidance Questionnaire, which assesses injury-related fear and avoidance behavior specifically in an athletic population, the Pain Catastrophizing Scale, the Hospital Anxiety and Depression Scale, and two Patient-Reported Outcomes Measurement Information System measures: Physical Function Computerized Adaptive Testing (CAT) and Pain Intensity CAT. RESULTS: After controlling for age, injury region (upper versus lower extremity), catastrophic thinking, and emotional distress, we found that an increase in athletes' fear avoidance was associated with a decrease in physical function (b = -0.32; p = 0.002). The model explained 30% of the variation in physical function with 7.3% explained uniquely by fear avoidance. After controlling for initial appointment/followup, surgery for the current condition, multiple pain conditions, history of prior sport-related injury/surgery, pain medication prescription, catastrophic thinking, and emotional distress, athletes' fear avoidance was not associated with pain (b = -0.14; p = 0.249). The model explained 40% of the variation in pain intensity and pain catastrophizing (b = 0.30; p = 0.001) uniquely explained 7.1% of this variation. CONCLUSIONS: In injured athletes, fear avoidance is independently associated with decreased physical function, whereas pain catastrophizing is associated with high pain intensity. Both level of an athlete's fear avoidance and catastrophic thinking about pain should be accounted for in clinical interventions aimed at helping athletes improve recovery and return to sport. LEVEL OF EVIDENCE: Level II, prognostic study.

Topographic Analysis of 2 Alternative Donor Sites of the Ipsilateral Elbow in the Treatment of Capitellar Osteochondritis Dissecans.

PURPOSE: To find the best topographic subchondral bone match between the capitellum and 2 proposed alternative donor sites of the ipsilateral elbow for capitellar osteochondral autologous transplantation: the non-articulating part of the radial head and the lateral olecranon tip. METHODS: In our retrospective database, 20 patients with an unremarkable computed tomography scan of the elbow despite clinical suspicion were identified for analysis. Included were patients aged 11 to 20 years with intact osseous structures and a computed tomography slice thickness of 1.25 mm or less. Three-dimensional polygon models were created using a standard predefined threshold, after which 4 articular surface lesions on the capitellum were created: central 40°, central 60°, lateral 40°, and lateral 60°. In addition, 3 donor locations on the non-articulating part of the radial head (diameter, 5 mm) and the lateral olecranon tip (diameter, 3.5 mm) were created. For each of 24 donor-recipient combinations, the donor graft surface was virtually placed on the recipient surface to quantify the mean distance between surfaces. RESULTS: The group of 20 patients consisted of 16 male and 4 female patients with a mean age of 15.9 years (range, 12-18 years). For a central 40° lesion, the mean distance across all 6 donor-recipient combinations ranged from 0.085 ± 0.023 to 0.118 ± 0.036 mm; for a central 60° lesion, the mean distance ranged from 0.075 ± 0.018 to 0.117 ± 0.062 mm; for a lateral 40° lesion, the mean distance ranged from 0.087 ± 0.030 to 0.182 ± 0.226 mm; and for a lateral 60° lesion, the mean distance ranged from 0.084 ± 0.048 to 0.115 ± 0.045 mm. There were no differences in topographic matching between donor-recipient combinations. CONCLUSIONS: The findings of this study show a less than 0.2-mm difference in the topographic subchondral bone match between 4 common lesion locations on the capitellum and 2 alternative donor sites of the ipsilateral elbow for capitellar osteochondral autologous transplantation: the non-articulating part of the radial head and the lateral olecranon tip. CLINICAL RELEVANCE: These findings suggest that the non-articulating part of the radial head and the lateral olecranon tip may potentially be used as a donor source when treating capitellar osteochondritis dissecans.

Effectiveness of reduction maneuvers in the treatment of nursemaid's elbow: A systematic review and meta-analysis.

BACKGROUND/AIM: Nursemaid's elbow usually occurs in young children when longitudinal traction is placed on the arm. Several manipulative maneuvers have been described, although, the most effective treatment technique is yet unclear. The aim of this systematic review and meta-analysis was to compare the two most commonly performed maneuvers (supination-flexion and hyperpronation) in the treatment of nursemaid's elbow. METHODS: A literature search was performed in PubMed, Embase, and Cochrane databases to identify randomized controlled trials comparing supination-flexion and hyperpronation. Data were extracted and pooled independently by two authors. Methodological quality assessment of included studies was performed. Meta-analysis was performed using a fixed-effect model in case of homogeneity across studies, and using a random-effect model in case of heterogeneity. Heterogeneity was calculated with the χ2 test and inconsistency in study effects across trials was quantified by I2 values. RESULTS: Seven randomized trials, including 701 patients (62% female), were included. A total of 350 patients were treated with the hyperpronation maneuver versus 351 patients who underwent the supination-flexion maneuver. Meta-analysis showed that hyperpronation was more effective than supination-flexion (risk ratio, 0.34; 95% confidence interval, 0.23 to 0.49; I2, 35%). The absolute risk difference between maneuvers was 26% in favor of hyperpronation, resulting in a number needed to treat of 4 patients. Trials lacked blinding of assessors and universal pain measures. CONCLUSIONS: Hyperpronation was more effective in terms of success rate and seems to be less painful compared to the supination-flexion maneuver in children with nursemaid's elbow.