ObjectivesCarpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Anatomic variations of the median nerve (MN) and carpal tunnel (CT) may predispose patients to CTS or increase procedural complexity and risk during carpal tunnel release (CTR). This study aimed to systematically evaluate the prevalence of 25 MN and CT anatomic variations and measurements using ultrasound (US) in patients referred for electrodiagnostic testing (EDX).MethodsIn this cross-sectional observational study, patients underwent diagnostic US exams of the MN (mid-brachium to distal CT), focused on variant anatomy that may predispose to CTS (bifid MN, Gantzer's muscle, lumbrical intrusion) or increase procedural complexity/risk (transligamentous thenar motor branches [TMBs], MN orientation ulnar to the palmaris longus [PL] tendon).ResultsTwo hundred and twenty patients (mean age: 45.3 +/- 13.0 years; 63.6% male; 294 UEs) were evaluated by US. Hundred and eight UEs met EDX criteria for CTS (EDX-CTS). The most common variations identified were lumbrical intrusion (81.3%), Gantzer's muscle (39.5%), and persistent median artery (22.8%), which were not associated with EDX-CTS. US revealed transligamentous (2.4%) and ulnar origin (4.5%) TMBs, which may increase injury risk during CTR. MN location was ulnar to the PL tendon in 70.4% of wrists, which can predispose to injury during landmark-guided CT injections.ConclusionsThis study demonstrated that US complements EDX and can systematically identify anatomic variations, including variants at risk during CTS interventions. No differences in the prevalence of variations were detected between patients with and without EDX-CTS. Diagnostic US can support procedural planning, improve safety, and lower injury risk.

Ultrasound imaging is vital for musculoskeletal assessment due to its real-time, high-resolution capabilities and safety. While protocols exist for rotator cuff evaluation, comprehensive guidelines for imaging the latissimus dorsi and teres major muscles are lacking. This article fills this gap by presenting a detailed ultrasound protocol for these muscles, essential for shoulder stability and movement in overhead athletes. We review their anatomy, propose a standardized examination approach, and discuss clinical indications, aiming to improve diagnostic accuracy and management of these injuries.

Osteoarthritis (OA) is a major global health problem with no disease-modifying therapies. Interleukin-1 (IL-1) is a critical cytokine associated with the pathophysiology of OA and can be inhibited by IL-1 receptor antagonist (IL-1Ra). Here, we tested the delivery of a gene therapeutic encoding the human IL-1Ra to the knee in a phase 1, open-label clinical trial that enrolled nine patients with radiographic knee OA. The IL-1Ra gene was delivered by a self-complementary (sc)–recombinant adeno-associated virus (rAAV) serotype 2.5 (sc-rAAV2.5IL-1Ra) by intra-articular injection into an index knee at one of three doses: low [1 × 10 11 viral genomes (vg)], mid (1 × 10 12 vg), or high (1 × 10 13 vg). The primary outcome was safety. There were no serious adverse events (AEs) related to sc-rAAV2.5IL-1Ra. Two AEs occurred that were possibly related to the vector. Both were effusions with increased pain and resolved with conservative treatment. sc-rAAV2.5IL-1Ra did not cause changes in vital signs, physical findings, or clinical laboratory measures. Less than 1% of the injected dose of sc-rAAV2.5IL-1Ra vg was detected in circulation after 1 day and was cleared within a week. Titers of neutralizing antibodies to AAV2.5 rose in serum and synovial fluid. In all cases, IL-1Ra concentration increased in the synovial fluid, and IL-1Ra concentrations remained elevated after 1 year. Baseline pain and function scores improved during the study. Therefore, we found that intra-articular gene therapy with sc-rAAV2.5IL-1Ra was safe. The sustained increase in local IL-1Ra in human knee joints supports the further clinical examination of this therapy to provide therapeutic benefit in OA.

Ultrasound imaging is vital for musculoskeletal assessment due to its real-time, high-resolution capabilities and safety. While protocols exist for rotator cuff evaluation, comprehensive guidelines for imaging the latissimus dorsi and teres major muscles are lacking. This article fills this gap by presenting a detailed ultrasound protocol for these muscles, essential for shoulder stability and movement in overhead athletes. We review their anatomy, propose a standardized examination approach, and discuss clinical indications, aiming to improve diagnostic accuracy and management of these injuries.

OBJECTIVES:Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Anatomic variations of the median nerve (MN) and carpal tunnel (CT) may predispose patients to CTS or increase procedural complexity and risk during carpal tunnel release (CTR). This study aimed to systematically evaluate the prevalence of 25 MN and CT anatomic variations and measurements using ultrasound (US) in patients referred for electrodiagnostic testing (EDX). METHODS:In this cross-sectional observational study, patients underwent diagnostic US exams of the MN (mid-brachium to distal CT), focused on variant anatomy that may predispose to CTS (bifid MN, Gantzer's muscle, lumbrical intrusion) or increase procedural complexity/risk (transligamentous thenar motor branches [TMBs], MN orientation ulnar to the palmaris longus [PL] tendon). RESULTS:Two hundred and twenty patients (mean age: 45.3 ± 13.0 years; 63.6% male; 294 UEs) were evaluated by US. One hundred and eight UEs met EDX criteria for CTS (EDX-CTS). The most common variations identified were lumbrical intrusion (81.3%), Gantzer's muscle (39.5%), and persistent median artery (22.8%), which were not associated with EDX-CTS. US revealed transligamentous (2.4%) and ulnar origin (4.5%) TMBs, which may increase injury risk during CTR. MN location was ulnar to the PL tendon in 70.4% of wrists, which can predispose to injury during landmark-guided CT injections. CONCLUSIONS:This study demonstrated that US complements EDX and can systematically identify anatomic variations, including variants at risk during CTS interventions. No differences in the prevalence of variations were detected between patients with and without EDX-CTS. Diagnostic US can support procedural planning, improve safety, and lower injury risk.

Anomalous muscles of the forearm, including a reversed palmaris longus, may present as masses or median nerve compression syndromes, such as carpal tunnel syndrome. In both cases, ultrasound may be used as a first-line diagnostic test. This report presents a case of a reversed palmaris longus with sonographic findings and anatomic correlation. The diagnosis of these muscular anomalies, their relationship to compression syndromes, and implications for surgical planning are discussed.

BACKGROUND:The use of musculoskeletal ultrasound (US) among hand surgeons appears to be increasing. The purpose of this study was to determine the utilization patterns and attitudes regarding US among American Society for Surgery of the Hand (ASSH) members in 2020 as well as the changes in usage patterns since a previous survey in 2015. METHODS:In 2020, an updated and expanded 27-question survey was distributed to 4852 members of the ASSH. Questions assessed respondent demographics, training, and practice patterns, and access, utilization, training, and opinions pertaining to US. RESULTS:A total of 418 surveys (8.6%) were analyzed. Compared to 2015, there was an increase in the percentage of respondents using US for diagnostic purposes (51%-68%), as well as having personal access to US machines (43% to 58%). US use to assist in diagnosing carpal tunnel syndrome increased from 19% to 27%. The most common reason for using US was convenience and practice efficiency, while the most common reasons for not using US was no machine access. In 2020, 33% of respondents performed US-guided injections. CONCLUSIONS:Compared to 2015, the majority of responding upper extremity surgeons now have personal access to US machines. Utilization of diagnostic US appears to be increasing, and two-thirds of respondents believed that US use will continue to increase among upper extremity surgeons.

Background: Scapholunate interosseous ligament injuries are prevalent and often challenging to diagnose radiographically. Four-dimensional CT allows visualization of carpal bones during motion. We present a cadaveric model of sequential ligamentous sectionings ("injuries") to quantify their effects on interosseous proximities at the radioscaphoid joint and scapholunate interval. We hypothesized that injury, wrist position, and their interaction affect carpal arthrokinematics.Methods: Eight cadaveric wrists were moved through flexion-extension and radioulnar deviation after injuries. Dynamic CT images of each motion were acquired in each injury condition using a second-generation dualsource CT scanner. Carpal osteokinematics were used to calculate arthrokinematic interosseous proximity distributions during motion. Median interosseous proximities were normalized and categorized by wrist position. Linear mixed-effects models and marginal means tests were used to compare distributions of median interosseous proximities.Findings: The effect of wrist position was significant for both flexion-extension and radioulnar deviation at the radioscaphoid joint; the effect of injury was significant for flexion-extension at the scapholunate interval; and the effect of their interaction was significant for radioulnar deviation at the scapholunate interval. Across wrist positions, radioscaphoid median interosseous proximities were less able to distinguish injury conditions versus scapholunate proximities. Median interosseous proximities at the scapholunate interval are majoritively able to detect differences between less (Geissler I-III) versus more (Geissler IV) severe injuries when the wrist is flexed, extended, and ulnarly-deviated.

Background: Chronic tendon retraction subsequent to distal biceps tendon rupture significantly increases repair difficulty and potential for tendon grafting. Biceps tendons that appear short or absent with magnetic resonance imaging (MRI) or that cannot be readily identified at surgery may erroneously be classified as irreparable. These apparent “absent” biceps tendons may actually be retracted and curled up inside the muscle, visually resembling the head-neck of a turtle retracted inside its shell (the “turtle neck sign”). When located, these tendons could be unfolded and repaired primarily. This type of tendon retraction seems to be associated with high-degree ruptures and larcertus fibrosus tears. Purpose: To test the hypothesis that tendon retractions with a turtle neck sign on MRI are more associated with high-degree ruptures and larcertus fibrosus tears versus tendon tears with simple linear retraction. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Retracted distal biceps tendon ruptures on sagittal MRI were categorized as linear retraction or curled-up (turtle neck) retraction. Retraction length, injury severity, and lacertus fibrosus tears were analyzed. Results: The authors retrospectively analyzed the patient records of 85 consecutive traumatic distal biceps tendon ruptures from 2003 to 2019; the final study cohort was 37 patients. Injury-to-surgery timing was as follows: <3 weeks, 43% (16 cases); 3 weeks to 3 months, 32% (12 cases); and >3 months, 24% (9 cases). Overall, 19 patients had linear retraction <7 cm (mean, 3.3 ± 1.9 cm) and 18 patients had a turtle neck retraction ≥7 cm (mean, 9.1 ± 1.6 cm). The injury-to-surgery time (median [± interquartile range]) was 27 days (±90 days) in the linear retraction group and 23 days (±65 days) in the turtle neck retraction group. The turtle neck retraction group had a significantly higher occurrence of abnormal hook test findings, complete distal biceps tendon rupture, and lacertus fibrosus tears compared with the linear retraction group (100% vs 58%, 100% vs 68%, and 100% vs 37%, respectively; P ≤ .02). However, significant repairability differences were not found. Conclusion: Highly retracted distal biceps turtle neck sign tendon ruptures occur frequently in association with high-degree ruptures and lacertus fibrosus tears. The presence of a turtle neck retraction did not affect reparability. Surgeons should be aware of this curled-up retraction to avoid mistaking it for an absent tendon or a muscle-tendon disruption.

A fiber optic surface plasmon resonance (SPR) biosensor for detection of Staphylococcal enterotoxin B (SEB) is reported. The sensor is based on spectral interrogation of surface plasmons in a miniature sensing element based on a side-polished single-mode optical fiber with a thin metal overlayer. For specific detection of SEB, the SPR sensor is functionalized with a covalently crosslinked double-layer of antibodies against SEB. The SPR biosensor is demonstrated to be able to detect ng/ml concentrations of SEB in less than 10 min.

BACKGROUND:The thumb annular pulley system is unique from the other digits and is integral to normal thumb function. Injuries to this pulley system can present a diagnostic challenge. No prior study has evaluated the ability of ultrasound (US) to evaluate all four thumb pulleys.OBJECTIVE:To validate the sonographic visualization of all four thumb pulleys.DESIGN:Prospective cadaveric laboratory investigation.SETTING:Academic center procedural skills laboratory.PARTICIPANTS:Twelve unembalmed cadaveric hands from seven adult male donors ages 78-89 years with body mass index 21.9-26.6 kg/m2 .INTERVENTIONS:Based on anatomic descriptions, a single examiner used a standardized protocol and high-frequency linear transducers to identify the A1, variable (Av), oblique (Ao), and A2 pulleys of the thumb in 10 cadaveric hands. As part of the validation process, the presumed Ao pulley was injected with diluted colored latex using US guidance. Two additional cadaveric specimens were dissected for detailed study of the thumb pulley system.MAIN OUTCOME MEASURES:Correlation between the four anatomic pulleys as revealed by dissection and the US findings, including identification of latex location with respect to the Ao pulley.RESULTS:US correctly identified all four thumb pulleys as distinct anatomic structures and the sonographic appearance of the pulleys correlated with the dissection in all 10 specimens. Latex was observed in the Ao pulley in 100% of the cadavers.CONCLUSIONS:Ultrasound can be used to accurately identify all four thumb pulleys, including distinct Ao and Av pulleys, and should be considered in the evaluation of thumb pulley injuries. This is the first study to validate the US visualization of the annular pulley system of the thumb.

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Osteoarthritis (OA) is a leading cause of disability with no cure and only supportive therapy. Adeno-associated virus (AAV) serotype 2.5 is being used in a Phase I clinical trial to deliver the interleukin-1 receptor antagonist into knee joints with OA. Neutralizing antibodies (Nab) directed against AAV2.5, if present, could inhibit gene transfer. Here, we report the prevalence of AAV2.5 Nab in the sera and synovial fluids of patients with OA. Nab titers were measured by their ability to inhibit in vitro transduction by AAV2.5 encoding GFP. Of 44 synovial fluids from patients with mid-stage and advanced OA, 43% had undetectable Nab; 25% had low titers (<1:100), 16% had medium titers (1:100–1:1000) and 16% had high titers (>1:1000) of Nab. Titers of AAV2.5 Nabs correlated with those of AAV2, but not with those of AAV5. Serum titers of AAV2.5 Nab correlated positively with titers in synovial fluid, and were never less than the matched synovial fluid titers. These findings suggest that high titers of Nab against AAV2.5 are uncommon in the synovial fluids of patients with OA, and individuals with high synovial fluid Nab titers can be identified by measuring titers in the serum.

Sports ultrasound is commonly used by sports medicine physicians to enhance diagnostic and procedural accuracy. This expert consensus statement serves as an update to the 2015 American Medical Society for Sports Medicine recommended sports ultrasound curriculum for sports medicine fellowships. Although written in the context of the American sports medicine fellowship training model, we present a stepwise progression in both diagnostic and interventional sports ultrasound that may be applicable to the broader sports medicine community. The curriculum is divided into 12 units with each unit including didactic instructional sessions, practical hands-on instruction, independent scanning practice sessions and mentored clinical experience. To assist with prioritisation of learning, we have organised relevant pathology and procedures as essential, desirable and optional. The expanded content can serve as an outline for continuing education postfellowship or for any physician to further advance their sports ultrasound knowledge and skill. We also provide updated scanning protocols, sample milestones and a sample objective structured clinical examination to aid fellowships with implementation of the curriculum and ongoing assessment of fellow progress.

This prospective case series compared the accuracy of ultrasound (US) to magnetic resonance imaging (MRI) in differentiating complete displaced (CD) thumb ulnar collateral ligament (UCL) tears from nondisplaced injuries in 10 patients with suspected traumatic thumb UCL injuries. Ultrasound identified 100% (2 of 2) of MRI‐documented CD tears, both of which were further confirmed during surgical repair. Ultrasound identified the absence of CD tears in the remaining 8 patients. Although MRI is the reference standard imaging modality for characterizing thumb UCL injuries, ultrasound should be considered an accurate, cost‐effective, and alternative imaging modality to differentiate surgical versus nonsurgical thumb UCL injuries.

Injury to the A2 pulley is caused by high eccentric forces on the flexor-tendon-pulley system. Accurate diagnosis is necessary to identify the most appropriate treatment options. This review summarizes the literature with respect to using ultrasound (US) to diagnose A2 pulley injuries, compares ultrasound to magnetic resonance imaging and computed tomography, and identifies current knowledge gaps. The results suggest that US should be used as the primary imaging modality given high accuracy, relatively low cost, ease of access, and dynamic imaging capabilities. Manual resistance is beneficial to accentuate bowstringing, but further research is needed to determine best positioning for evaluation.

Purpose We evaluated biological effects of distinct local anesthetics on human adipose-derived mesenchymal stem cells when applied to reduce periprocedural pain during mesenchymal stem cell injections. Methods and Materials Metabolic activity (MTS assay), viability (Live/Dead stain), and gene expression (quantitative real-time reverse-transcriptase polymerase chain reaction) were measured in mesenchymal stem cells incubated with various concentrations of lidocaine, ropivacaine, or bupivacaine during a 12-hr time course. Results Cell viability and metabolic activity decreased in a dose, time, and substance-specific manner after exposure to lidocaine, ropivacaine, and bupivacaine, with ropivacaine being the least cytotoxic. Cell viability decreases after brief exposure (<1.5 hrs) at clinically relevant concentrations (eg, 8 mg/ml of lidocaine, 2.5 mg/ml of ropivacaine or bupivacaine). Mesenchymal stem cells exposed to local anesthetics change their expression of mRNA biomarkers for stress response (EGR1, EGR2), proliferation (MKI67, HIST2H4A), ECM (COL1A1, COL3A1), and cell surface marker (CD105). Conclusions Local anesthetics are cytotoxic to clinical-grade human mesenchymal stem cells in a dose-, time-, and agent-dependent manner and change expression of ECM, proliferation, and cell surface markers. Lidocaine and bupivacaine are more cytotoxic than ropivacaine. Single-dose injections of local anesthetics may affect the biological properties of mesenchymal stem cells in vitro but may not affect the effective dose of MSCs in a clinical setting.

This paper aims to review the currently available ultrasound imaging technologies in musculoskeletal studies by showcasing recent representative works in the field. Brief comments on the technical characteristics and potential advancement of these technologies are provided. Other than the conventional brightness-mode (B-mode) ultrasound, recent ultrasound imaging technologies used for investigating musculoskeletal systems mainly include ultrasound elastography (UE), photoacoustic imaging (PAI), contrast agent-enhanced ultrasound (CEUS) imaging, and three-dimensional (3D) ultrasound imaging. Current ultrasound imaging technologies provided a variety of noninvasive tools for studying specific problems in musculoskeletal systems. 3D volumetric imaging capability and incorporating the recent developments of artificial intelligence (AI) will potentially advance the current technologies more comprehensive and robust.

HISTORY: A 44 year-old female runner presented with four weeks of migrating left anteromedial and posterolateral hip pain. Pain was gradual in onset but worsened after a 20 mile run three weeks prior. Pain was worse with running and weight-bearing activities. She tried a run the day prior to her visit but stopped at five miles due to pain. Ibuprofen improved her symptoms. She denied weakness, paresthesias, night pain, pain with lying on her left side, or mechanical symptoms. She hoped to run in the Boston Marathon, which was 13 days after her initial visit. PHYSICAL EXAMINATION: Patient was tender to palpation over the gluteal musculature and greater trochanteric region however this was not her typical pain. Hip range of motion and strength were full. Resisted hip abduction was painful. Stinchfield reproduced posterior buttock pain. Log roll, labral scour, FABER, FADIR, and ischiofemoral impingement maneuvers were negative. Reflexes and sensation were intact. DIFFERENTIAL DIAGNOSIS 1. Greater trochanteric pain syndrome 2. Femoral acetabular impingement 3. Myofascial pain 4. Piriformis syndrome 5. Stress fracture TESTS AND RESULTS Hip X-ray: Mild degenerative change of bilateral hips. No fracture. Hip MRI: Evidence of left gluteal tendinopathy and associated greater trochanteric bursitis. Increased T2 signal along the proximal femoral diaphysis. No femoral neck stress fracture. Femur MRI: Periosteal edema along the medial proximal femoral shaft with periosteal thickening and trace underlying bone marrow edema.FINAL WORKING DIAGNOSIS Adductor insertion avulsion syndrome (thigh splints) TREATMENT AND OUTCOMES 1. Partial weight-bearing with crutches with progression to full weight-bearing over two weeks as pain with walking improved. 2. Physical therapy with a return to running program and running analysis. 3. Discussed the risks of stress fracture or complete fracture if continued to run. 4. Patient ran in the Boston Marathon and finished in just over four hours.