Patient-Reported and Clinical Outcomes After Tendon Autograft Reconstruction of the Thumb Ulnar Collateral Ligament.

PURPOSE: This study aimed to report clinical and patient-reported outcomes collected in a registry after thumb ulnar collateral ligament (UCL) reconstruction with a free tendon autograft. Furthermore, the patient-reported outcomes of patients with persistent instability after reconstruction and patients with concomitant metacarpophalangeal joint arthritis diagnosed during surgery were analyzed. METHODS: Patients undergoing reconstruction with a tendon autograft between December 2011 and February 2021 were included. Michigan Hand Outcomes Questionnaire (MHQ) scores at baseline were compared with those at 3 and 12 months after surgery. Stability was tested at 3 months after surgery. Tip and key pinch strength and metacarpophalangeal joint range of motion were measured at baseline and 12 months after surgery. RESULTS: We included 31 patients with thumb UCL insufficiency or failed UCL surgery who underwent reconstruction. The MHQ total score improved significantly from 62 at baseline to 75 at 3 months and continued to increase to 84 at 12 months after surgery. The MHQ function and pain scores improved significantly from intake to 3 and 12 months after surgery. Twenty-six of 31 patients (84%) regained postoperative metacarpophalangeal stability. Key pinch strength improved significantly 12 months after surgery from 5.2 kg at baseline to 6.4 kg at 12 months. The MHQ total, pain, and function scores of patients with persistent instability remained similar from baseline to 12 months after surgery. In four patients with metacarpophalangeal arthritis, the MHQ total and pain score improved significantly from baseline to 3 and 12 months after surgery. CONCLUSIONS: Patient-reported outcomes, including pain and function, improved after thumb UCL reconstruction with a tendon autograft. Although the sample size of patients with thumb metacarpophalangeal arthritis diagnosed during surgery was small, they reached adequate patient-reported outcomes at 12 months after surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Graft choice and techniques used in elbow ulnar collateral ligament reconstruction over the last 20 years: a systematic review and meta-analysis.

BACKGROUND: Elbow medial ulnar collateral ligament (mUCL) injuries have become increasingly common, leading to a higher number of mUCL reconstructions (UCLR). Various techniques and graft choices have been reported. The purpose of this study was to evaluate the prevalence of each available graft choice, the surgical techniques most utilized, and the reported complications associated with each surgical method. METHODS: A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysesguidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify all articles that included UCLR between January 2002 and October 2022. We included all studies that referenced UCLR graft choice, surgical technique, and/or ulnar nerve transposition. Studies were evaluated in a narrative fashion to assess demographics and report current trends in utilization and complications of UCLR as they pertain to graft choice and surgical techniques over the past 20 years. Where possible, we stratified based on graft and technique. RESULTS: Forty-seven articles were included, reporting on 6671 elbows. The cohort was 98% male, had a weighted mean age of 21 years and follow-up of 53 months. There were 6146 UCLRs (92%) performed with an autograft and 152 (2.3%) that utilized an allograft, while 373 (5.6%) were from mixed cohorts of autograft and allograft. Palmaris longus autograft was the most utilized mUCL graft choice (64%). The most utilized surgical configuration was the figure-of-8 (68%). Specifically, the most common techniques were the modified Jobe technique (37%), followed by American Sports Medicine Institute (ASMI) (22%), and the docking (22%) technique. A concomitant ulnar nerve transposition was performed in 44% of all patients, with 1.9% of these patients experiencing persistent ulnar nerve symptoms after ulnar nerve transposition. Of the total cohort, 14% experienced postoperative ulnar neuritis with no prior preoperative ulnar nerve symptoms. Further, meta-analysis revealed a significantly greater revision rate with the use of allografts compared to autograft and mixed cohorts (2.6% vs. 1.8% and 1.9%, P = .003). CONCLUSIONS: Most surgeons performed UCLR with palmaris autograft utilizing a figure-of-8 graft configuration, specifically with the modified Jobe technique. The overall rate of allograft use was 2.3%, much lower than expected. The revision rate for UCLR with allograft appears to be greater compared to UCLR with autograft, although this may be secondary to limited allograft literature.

Pre-Draft Elbow Magnetic Resonance Imaging in Major League Baseball Pitchers.

BACKGROUND: Prior to the Major League Baseball (MLB) draft, some pitchers undergo pre-draft magnetic resonance imaging (MRI). This study aimed to evaluate pre-draft elbow MRI on baseball pitchers who were entering the MLB draft to determine the presence or absence of pathology, the associations between these pathologies and UCL tears, and inter-observer reliability regarding common MRI pathology. METHODS: Pre-draft elbow MRI performed on prospective MLB pitchers between 2011-2017 were de-identified and then reviewed by two separate authors. The authors graded the MRI on several factors including presence or absence of: UCL ossification, UCL appearance (heterogeneous or not), UCL thickening (and location), UCL tear (partial vs. full thickness and location), muscle strain, flexor tendon tear, posteromedial osteophyte, sublime tubercle enthesophyte, and osseous stress reactions. RESULTS: Overall, 245 pre-draft elbow MRI were reviewed. MRI abnormalities were found in 70% (171/245) of pitchers. UCL thickening was found in 20% (50/245) of pitchers. Regarding UCL tears, 3% had a full thickness tear and 24% had a partial thickness tear. Of full thickness tears, 86% were distal and one was midsubstance. Of partial thickness tears, 41% (24/58) were distal, 12% (7/58) were midsubstance, and 47% (27/58) were proximal. Periligamentous edema was present in 36% of pitchers while 14% had a flexor pronator muscle strain. CONCLUSION: The majority (70%) of pitchers entering the MLB draft had abnormal findings on their MRI, most commonly involving changes to the UCL. Inter-observer reliability was acceptable following the definition of pathology when reading pre-draft elbow MRI on MLB prospects.

Halide Superionic Conductors with Non-Close-Packed Anion Frameworks.

Halide superionic conductors (SICs) are drawing significant research attention for their potential applications in all-solid-state batteries. A key challenge in developing such SICs is to explore and design halide structural frameworks that enable rapid ion movement. In this work, we show that the close-packed anion frameworks shared by traditional halide ionic conductors face intrinsic limitations in fast ion conduction, regardless of structural regulation. Beyond the close-packed anion frameworks, we identify that the non-close-packed anion frameworks have great potential to achieve superionic conductivity. Notably, we unravel that the non-close-packed UCl3-type framework exhibit superionic conductivity for a diverse range of carrier ions, including Li+, Na+, K+, and Ag+, which are validated through both ab initio molecular dynamics simulations and experimental measurements. We elucidate that the remarkable ionic conductivity observed in the UCl3-type framework structure stems from its significantly more distorted site and larger diffusion channel than its close-packed counterparts. By employing the non-close-packed anion framework as the key feature for high-throughput computational screening, we also identify LiGaCl3 as a promising candidate for halide SICs. These discoveries provide crucial insights for the exploration and design of novel halide SICs.

A Comparative Study of Thumb Metacarpal Morphology and Shape Categorization.

PURPOSE: To describe the shape of a biplanar thumb metacarpal (MC) head and identify how it differs morphologically from previously described flat and round MC heads. METHODS: Lateral radiographs of the thumb were collected retrospectively from our patient database. Patients were included in the study if they had an appropriate lateral radiograph, met the age criteria (range; 18-75 years), and did not have severe metacarpophalangeal (MCP) joint arthritis. Metacarpal heads were categorized as flat or round by dividing the distance measured from the volar to the dorsal edge of the articular surface by the radius of curvature of the articular surface. A ratio of 1.7 or greater indicated a round MC head, whereas a ratio of less than 1.7 indicated a flat MC head. RESULTS: Among the 210 study participants, 110 were female and the average age was 47.3 years. During the measurement and classification process, it was determined by a board-certified hand surgeon that a subset of MCs did not meet the criteria for being categorized as either flat or round because of the inability to appropriately measure the radius of curvature of the MCP joint. Of the participants 113, 79, and 18, were classified as having either round, flat, or biplanar MC head shapes, respectively. CONCLUSIONS: We have identified a third, biplanar MC head shape. The biplanar head shape is more triangular and has two distinct planes on the articular surface that converge into an apex. CLINICAL RELEVANCE: The shape of the MC head has been shown to influence the range of motion of the MCP joint which may have an influence on the types of injuries that occur at the MCP joint. Further studies are required to understand how shape classification of MC heads may be useful and relevant to range of motion and risk of injury.

Patient-Reported Outcomes and Function After Surgical Repair of the Ulnar Collateral Ligament of the Thumb.

PURPOSE: The purpose of this study was to report prospectively collected patient-reported outcomes of patients who underwent open thumb ulnar collateral ligament (UCL) repair and to find risk factors associated with poor patient-reported outcomes. METHODS: Patients undergoing open surgical repair for a complete thumb UCL rupture were included between December 2011 and February 2021. Michigan Hand Outcomes Questionnaire (MHQ) total scores at baseline were compared to MHQ total scores at three and 12 months after surgery. Associations between the 12-month MHQ total score and several variables (i.e., sex, injury to surgery time, K-wire immobilization) were analyzed. RESULTS: Seventy-six patients were included. From baseline to three and 12 months after surgery, patients improved significantly with a mean MHQ total score of 65 (standard deviation [SD] 15) to 78 (SD 14) and 87 (SD 12), respectively. We did not find any differences in outcomes between patients who underwent surgery in the acute (<3 weeks) setting compared to a delayed setting (<6 months). CONCLUSIONS: We found that patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline. We did not find an association between injury to surgery time and lower MHQ total scores. This suggests that acute repair for full-thickness UCL tears might not always be necessary. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

What are the indications for medial ulnar collateral ligament surgery in baseball players? An MRI case-based study.

BACKGROUND: Ulnar collateral ligament (UCL) tears are common in baseball players. When nonoperative management fails; reconstruction or repair may be necessary to restore physical function. There is no clear consensus regarding the indications for surgery based on magnetic resonance imaging (MRI) tear characteristics or the indications for selecting repair over reconstruction. The purpose of this study was to define the indications for UCL surgery based on MRI and to elucidate indications for UCL repair vs. reconstruction. METHODS: Twenty-six orthopedic surgeons who treat baseball players were surveyed. Forty-five MRIs were reviewed: 15 without UCL tears, 15 with intraoperatively confirmed partial-thickness tears, and 15 with full-thickness tears. Factors investigated included ligament characteristics (periligamentous or osseous edema, ligament hypertrophy, calcification, partial or full-thickness tearing) and location (proximal, midsubstance, or distal). Surgeons were given a clinical scenario and asked whether 1) surgery was indicated and 2) whether repair or reconstruction was recommended. Odds ratios (OR) and 95% confidence intervals (95% CI) helped identify significant predictors for both queries. RESULTS: The odds of recommending surgical treatment compared to nonoperative treatment were 2.4× more likely for a proximal partial-thickness tear, 3.2× for distal partial-thickness tear, 5.1× for distal full-thickness tear, and 7.0× for proximal full-thickness tear (P < .001). Significant indications for repair included distal partial (OR = 1.6, 95% CI 1.0, 2.1, P < .001) and full-thickness tears (OR = 1.7, 95% CI 1.1, 2.3, P < .001). Repair was 3× less likely recommended for midsubstance full-thickness tears (OR = 3.0, 95% CI -5.0, -1.0, P = .004). Ultrasound stress testing was requested in 78% of partial tears. CONCLUSIONS: Among surgeons surveyed, the highest odds for recommending operative treatment were proximal full-thickness tears, then distal full-thickness, distal partial-thickness, and proximal partial-thickness tears. Repair was most appropriate for partial and full-thickness distal tears, but relatively contraindicated for complete midsubstance UCL tears. Ultrasound stress testing was frequently requested for partial tears. Given the lack of consensus among surgeons, future prospective registries are necessary to determine whether these factors associate with clinical outcomes.

Reliability of ulnar collateral ligament findings in magnetic resonance imaging.

BACKGROUND: Ulnar collateral ligament (UCL) tears are common in baseball players. Although magnetic resonance imaging (MRI) is the most used imaging modality for UCL injuries, the inter-rater reliability of MRI analyzing specific characteristics of UCL pathology has not been defined. The purpose of this study was to define the inter-rater reliability of MRI for evaluating UCL characteristics. METHODS: Three surgeons analyzed 45 noncontrast MRIs: 15 without UCL tears, 15 with intraoperatively confirmed partial-thickness tears, and 15 with intraoperatively confirmed full-thickness tears. Findings evaluated included ligament characteristics (periligamentous or osseous edema, ligament hypertrophy, calcifications, and partial- or full-thickness tearing) and location of the pathology (proximal, midsubstance, or distal). Fleiss' κ coefficients were used to assess interobserver reliability. RESULTS: There were high rates of agreement for midsubstance (κ: 0.50) and distal (κ: 0.69) ligament edema and proximal osseous edema (κ: 0.48). There were low rates of agreement for proximal ligament edema (κ: 0.08), ligament thickening (κ: -0.02 to 0.20), and proximal to midsubstance calcifications (κ: -0.04 to 0.10). Midsubstance (κ: 0.55) and distal full-thickness tears (κ: 0.63) demonstrated higher agreement than proximal (κ: 0.29). Proximal partial-thickness tears (κ: 0.45) had higher agreement than midsubstance (κ: -0.02) or distal (κ: -0.02). CONCLUSIONS: In our study, there was high inter-rater reliability regarding proximal osseous edema, midsubstance, and distal ligament edema and full-thickness tears. There was no agreement for midsubstance and distal partial-thickness UCL tears, but fair agreement for proximal tears. UCL tissue characteristics including ligament thickening and calcifications demonstrated low agreement. Challenges remain in effectively evaluating UCL tissue characteristics on noncontrast MRIs.

Accelerated rehabilitation following thumb ulnar collateral ligament repair with suture tape augmentation: A case series of professional basketball players.

STUDY DESIGN: Case series. INTRODUCTION: Rehabilitation protocols following thumb metacarpophalangeal (MCP) ulnar collateral ligament (UCL) repair typically do not allow for return to sport until 12 weeks post-surgery. The potential for accelerated rehabilitation following thumb MCP UCL repair with suture tape augmentation has yet to be explored. PURPOSE OF THE STUDY: To describe the accelerated rehabilitation following thumb MCP UCL repair with the suture tape augmentation in professional basketball players. METHODS: Three professional basketball players underwent thumb MCP UCL repair with suture tape augmentation. The athletes followed an accelerated rehabilitation program post-surgery that began with range-of-motion exercises at 2-3 days, proximal strengthening at 7-10 days, grip/pinch strengthening at 1-2 weeks, followed by progressive sport specific intervention with a custom orthosis. RESULTS: At 5-6 weeks post-surgery, active thumb MCP range of motion returned to 83%-100%, grip strength to 81%-100%, and tripod pinch strength to 73%-78% of the contralateral side. All athletes successfully returned to sport within 5-6 weeks post-surgery. DISCUSSION/CONCLUSION: This is the first clinical application of an accelerated rehabilitation protocol in athletes following thumb MCP UCL repair. In this series, professional basketball players were able to return to sport in half the routine recovery time. Further prospective studies re-thinking current rehabilitation protocols are warranted.

The Universal Super Cation-Conductivity in Multiple-cation Mixed Chloride Solid-State Electrolytes.

As exciting candidates for next-generation energy storage, all-solid-state lithium batteries (ASSLBs) are highly dependent on advanced solid-state electrolytes (SSEs). Here, using cost-effective LaCl3 and CeCl3 lattice (UCl3 -type structure) as the host and further combined with a multiple-cation mixed strategy, we report a series of UCl3 -type SSEs with high room-temperature ionic conductivities over 10-3  S cm-1 and good compatibility with high-voltage oxide cathodes. The intrinsic large-size hexagonal one-dimensional channels and highly disordered amorphous phase induced by multi-metal cation species are believed to trigger fast multiple ionic conductions of Li+ , Na+ , K+ , Cu+ , and Ag+ . The UCl3 -type SSEs enable a stable prototype ASSLB capable of over 3000 cycles and high reversibility at -30 °C. Further exploration of the brand-new multiple-cation mixed chlorides is likely to lead to the development of advanced halide SSEs suitable for ASSLBs with high energy density.

Coping strategies and quality of life in patients with chronic symptoms visiting a Lyme Center in a Dutch teaching hospital.

INTRODUCTION: Little is known on coping strategies in patients with chronic symptoms suspected of Lyme borreliosis (LB). Different coping strategies might influence quality of life (QoL). We assessed coping strategies and QoL in patients with chronic symptoms suspected of LB. METHODS: Adult patients referred to the Lyme Center Apeldoorn were included (November 2019-April 2021). Participants completed the RAND-36 to assess QoL and the Utrecht Coping List to assess coping strategies. Patient data were extracted from medical records. Patients were categorized based on clinical LB and serology. Linear regression analyses were conducted to examine an association between coping strategies and QoL subscales. RESULTS: Included were 201 patients. Patients suspected of LB had a different coping profile and lower QoL compared to the reference population. Patients with negative serology and no clinical LB scored lowest on all QoL subscales. In multivariate analyses, correcting for age, gender, comorbidity, and patient category, a negative association was found between passive coping and the QoL subscales physical functioning (ß(SE) = - 1.1(0.5)), social functioning (ß(SE) = - 3.3(0.5)), role limitations (emotional) (ß(SE) = - 5.5(0.8)), mental health (ß(SE) = - 3.7(0.3)), vitality (ß(SE) = - 2.3(0.3)), pain (ß(SE) = - 2.3(0.5)), and general health (ß(SE) = - 2.7(0.3)). A negative association was also found between palliative coping and the QoL subscale role limitations (physical) (ß(SE) = - 1.8(0.6)) and between expressing emotions and mental health (ß(SE) = - 1.3(0.6)). A positive association was found between active coping and the QoL subscales mental health (ß(SE) = 1.0(0.3)) and role limitations (emotional) (ß(SE) = 1.9(0.8)). CONCLUSION: In patients suspected of LB, dysfunctional coping strategies were associated with worse quality of life. There is a need for interventions that can guide patients with chronic symptoms suspected of LB towards more active coping and increase QoL.

Elbow Ulnar Collateral Ligament Injuries in Throwing Athletes: Diagnosis and Management.

Ulnar collateral ligament (UCL) injuries of the elbow are common in overhead throwing athletes. With throwing, the elbow experiences substantial valgus stress and repetitive microtrauma can lead to injury. Increasing rates of injury among both youth and professional throwers has resulted in a "UCL epidemic." Ulnar collateral ligament reconstruction ("Tommy John Surgery") became a part of the public consciousness after Tommy John returned to professional baseball after a UCL reconstruction with Dr Frank Jobe for what was once considered a career-ending injury. Partial tears and some athletes with complete UCL injuries can be managed without surgery. Since the introduction of UCL reconstruction, technical modifications have aimed to decrease complications and increase return-to-play rates. Ulnar collateral ligament repair has reemerged as a potential surgical option for some throwers. Future prospective and comparative studies are necessary to better define the optimal operative treatment for these injuries.

Ulnar collateral ligament reconstruction in javelin throwers: an analysis of return to play rates and patient outcomes.

BACKGROUND: Although results after ulnar collateral ligament reconstruction (UCLR) in baseball players have been well documented, the literature is replete regarding the outcomes after UCLR in javelin throwers. PURPOSE: To report outcomes after UCLR in javelin throwers. HYPOTHESIS: UCLR in javelin throwers will result in a high rate of return to play similar to that of previously published studies from athletes of other sports. METHODS: All patients who were identified preoperatively as javelin throwers and underwent UCLR between 2011 and 2017 with a minimum 2-year follow-up were eligible for inclusion. Patients were assessed with the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow score, Timmerman-Andrews Elbow score, Conway-Jobe score, patient satisfaction, return to sport rate questionnaire, and the occurrence of any postoperative complications. RESULTS: Eighteen patients met the inclusion criteria. Complete follow-up was available in 16 (88.9%) patients. The average age at surgery was 21.2 ± 2.0 (range, 18.6-24.9) years. At the final follow-up, the average Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow score and Timmerman-Andrews Elbow score were 77.3 (range, 18.7-98.4) and 91.8 (range, 70.0-100.0), respectively. Outcomes on the Conway-Jobe scale were as follows: excellent (n = 6; 37.5%), good (n = 4; 25%), fair (n = 6; 37.5%). Ten (62.5%) patients returned to play at an average of 12.2 ± 3.6 (range, 6.0-18.0) months after surgery. Two (12.5%) patients sustained a shoulder injury postoperatively; however, neither required surgery. CONCLUSION: UCLR in javelin throwers results in good outcomes with a low rate of reinjury/reoperation. However, the return to play rate (62.5%) and good/excellent outcomes per the Conway-Jobe scale (68.8%) are lower than what has been previously reported in baseball players and javelin throwers. Further investigation regarding outcomes in javelin throwers after UCLR is warranted.

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.

Sites of flexor-pronator muscle injury and relationship between ulnar collateral ligament injury and flexor-pronator muscle injury in baseball players: a retrospective cohort study.

BACKGROUND: Ulnar collateral ligament (UCL) and flexor-pronator muscle (FPM) injuries are common in baseball players. However, the sites of FPM injuries and the relationship between UCL and FPM injuries in baseball players have not been fully clarified. The purpose of this study was to identify the sites of FPM injuries and to determine the relationships of location and severity of UCL injury with the presence of FPM injuries in baseball players. METHODS: UCL and FPM injuries were diagnosed using magnetic resonance imaging in 99 baseball players. The sites of FPM injuries were identified on coronal, sagittal, and axial images. UCL injury severity was classified into four grades: chronic changes, low-grade partial tear, high-grade partial tear, and complete tear. UCL injury location was classified as proximal UCL tear or distal UCL tear. All images were assessed by a musculoskeletal radiologist and an orthopedic surgeon. RESULTS: Combined UCL and FPM injuries were observed in 45 of 99 players, of which 40 of 45 (89%) involved injury of the flexor digitorum superficialis (FDS). All FDS injuries were in the deep layer of the muscle belly. There was no significant difference between the severity of UCL injury and presence of FPM injuries (P = .352). There was a significant association of distal UCL tears with FPM injuries (P < .001). CONCLUSION: FDS injury occurs most commonly in the muscle belly of the second and fifth digits. There may be no relationship between the severity of UCL injury and presence of FPM injury in baseball players. FPM injuries may be a contributing factor in the failure of nonoperative management of distal UCL tears in baseball players.

The relationship between shoulder range of motion and elbow stress in college pitchers.

HYPOTHESIS: College pitchers with increased external rotation gain (ERG) produce increased medial elbow torque (elbow stress) whereas those with reduced total rotational range of motion (ROM) have reduced medial elbow torque during pitching. METHODS: Pitchers were recruited from 3 college baseball teams. Players with prior injury or on pitching restrictions because of pain were excluded. Players were evaluated within 2 weeks before their first game of the season. Pitchers completed an intake survey, and shoulder and arm measurements were taken. Pitchers were fitted with a baseball sleeve that included a sensor at the medial elbow. The sensor calculated elbow torque, arm speed, arm slot, and shoulder rotation for each pitch, while a radar gun measured peak ball velocity. After adequate warm-up, pitchers threw 5 fastballs in a standardized manner off the mound at game-speed effort. The primary outcome evaluated the relationship between shoulder ROM and medial elbow torque. Additional outcomes evaluated pitcher characteristics and demographic characteristics in the context of shoulder ROM. RESULTS: Twenty-eight pitchers were included in the preseason analysis. The average age and playing experience were 20.1 years (standard deviation [SD], 1.3 years) and 15.3 years (SD, 1.8 years), respectively, with 2.5 years (SD, 1.2 years) playing at collegiate level. The dominant shoulder showed decreased internal rotation and increased external rotation (ER) relative to the nondominant side (P < .001). The average glenohumeral internal rotation deficit and ERG were 11.3° (SD, 9.87°) and 5.71° (SD, 8.8°), respectively. ERG ≥ 5° was a significant predictor of elbow stress during pitching (47.4 Nm [SD, 0.7 Nm] vs. 45.1 Nm [SD, 0.6 Nm], P = .014). Univariate associations showed that each additional degree of ER resulted in increased elbow torque (ß estimate, 0.35 ± 0.06 Nm; P = .003). Conversely, decreased medial elbow torque was found in pitchers with reduced shoulder ROM (glenohumeral internal rotation deficit ≥ 20°: 43.5 Nm [SD, 1.1 Nm] vs. 46.6 Nm [SD, 0.5 Nm], P = .011; loss of total rotational ROM ≥ 5°: 43.6 Nm [SD, 1.1 Nm] vs. 46.6 Nm [SD, 0.5 Nm], P = .013) and in those with greater arm length (P < .05). CONCLUSIONS: College pitchers with increased ER produce greater medial elbow torque during the pitching movement. Each degree of increased ER was found to correlate with increased elbow torque and ball velocity. On the contrary, arm length and reduced shoulder ROM were associated with reduced medial elbow torque. This study suggests that increased ER in pitchers is associated with greater elbow stress during pitching.

Material Properties of the Medial Elbow During Passive Valgus and Self-Initiated Varus Torques.

Shear wave elastography imaging of the ulnar collateral ligament (UCL) is used to help understand changes in material properties of the ligament. Ensuring that the wrist flexors are relaxed is essential as muscle contractions can alter the alignment of the medial elbow. The purpose of this study was to determine how the structural and material properties of the medial elbow respond to various elbow torques. The medial elbows of 20 healthy adults, free from upper extremity disorders, were imaged in 3 of the following torque conditions: (1) neutral relaxed, (2) passive valgus, and (3) active varus. Structural properties (ulnohumeral gap and UCL length) using B-mode and material properties (UCL and flexor muscle stiffness) using shear wave were measured. Passive valgus torque opened the ulnohumeral gap (P < .001), and increased UCL (P < .001) and wrist flexor stiffness (P = .001), compared with the neutral condition. Under an active varus contraction, the gap returned back to the neutral position, but UCL (P < .008) and wrist flexor stiffness (P < .004) remained elevated compared with neutral, meaning low-intensity torques can influence structural and material properties of the medial elbow. Therefore, effort should be taken to minimize muscle activation during imaging in order to accurately measure medial elbow properties.

Spermatogonial kinetics in humans.

The human spermatogonial compartment is essential for daily production of millions of sperm. Despite this crucial role, the molecular signature, kinetic behavior and regulation of human spermatogonia are poorly understood. Using human testis biopsies with normal spermatogenesis and by studying marker protein expression, we have identified for the first time different subpopulations of spermatogonia. MAGE-A4 marks all spermatogonia, KIT marks all B spermatogonia and UCLH1 all Apale-dark (Ap-d) spermatogonia. We suggest that at the start of the spermatogenic lineage there are Ap-d spermatogonia that are GFRA1High, likely including the spermatogonial stem cells. Next, UTF1 becomes expressed, cells become quiescent and GFRA1 expression decreases. Finally, GFRA1 expression is lost and subsequently cells differentiate into B spermatogonia, losing UTF1 and acquiring KIT expression. Strikingly, most human Ap-d spermatogonia are out of the cell cycle and even differentiating type B spermatogonial proliferation is restricted. A novel scheme for human spermatogonial development is proposed that will facilitate further research in this field, the understanding of cases of infertility and the development of methods to increase sperm output.

Importance of radar gun inclusion during return-to-throwing rehabilitation following ulnar collateral ligament reconstruction in baseball pitchers: a simulation study.

BACKGROUND: Rehabilitation following elbow ulnar collateral ligament reconstruction in baseball pitchers relies on a progression of pitching activities to ensure protection and gradual strengthening of the reconstructed ligament. The purpose of this study was to determine the medial elbow torque associated with pitches at various effort levels and determine whether radar gun assistance improves players' abilities to accurately match partial-effort pitches with true references based on maximum pitch velocity. METHODS: Thirty-seven healthy high school and collegiate baseball pitchers were included in this study. Participants were excluded if they were injured, recovering from injury, or otherwise not currently pitching at full effort. Pitch parameters were collected using a validated wearable sensor. Participants threw 5 pitches at 50%, 75%, and 100% subjective effort. Pitchers then threw 5 pitches at 50% maximum velocity and 75% maximum velocity, as measured by a radar gun. RESULTS: Thirty-seven pitchers completed this study. Pitches thrown at 50% and 75% partial effort were significantly faster and generated higher elbow torque than did pitches thrown at 50% and 75% velocity, respectively (P < .001). A 10% decrease in percentage of maximum velocity was associated with a 13% decrease in percentage of maximum elbow torque (ß coefficient = 1.3, R2 = 0.81, P < .001). CONCLUSION: Pitchers generate higher-than-intended forces when throwing at 50% and 75% effort during a subjective partial-effort throwing protocol. Use of a radar gun to guide partial-effort throwing during throwing rehabilitation programs may protect the reconstructed elbow from excess medial torque.

Valgus stress ultrasound for medial ulnar collateral ligament injuries in athletes: is ultrasound alone enough for diagnosis?

BACKGROUND: We hypothesized that valgus stress ultrasound would be useful for both identifying medial ulnar collateral ligament (MUCL) tears and assessing the severity of the tears. Hence, we performed valgus stress ultrasound of the elbow in athletes with MUCL injuries, confirmed by magnetic resonance imaging (MRI), to determine whether ultrasound can be used as a diagnostic tool. METHODS: Stress ultrasound and MRI data from 146 athletes with medial elbow pain were compared prospectively. MRI findings for MUCL injuries were classified into 3 levels as follows: low-grade partial tear (≤50%), high-grade partial tear (>50%), and complete tear. The degree of joint laxity on stress ultrasound was evaluated by measuring joint gapping after applying a 2.5-kg load to the wrist. Joint gapping was measured at 30° and 90° of elbow flexion for the dominant arm and nondominant arm, and the differences between the dominant and nondominant arms were determined. RESULTS: A higher degree of MUCL injury on MRI was associated with greater joint gapping in the medial elbow on stress ultrasound. At 30° of elbow flexion, the cutoff value for complete MUCL rupture was 0.5 mm (P < .001), with a sensitivity and specificity of 88.1% and 61.5%, respectively. At 90° of elbow flexion, the cutoff value for complete MUCL rupture was 1.0 mm (P < .001), with a sensitivity and specificity of 81.0% and 66.4%, respectively. CONCLUSION: Stress ultrasound can be used to diagnose complete MUCL tears in athletes when joint gapping is greater than 0.5 mm at 30° of elbow flexion and greater than 1 mm at 90° of elbow flexion.