Citations

Abstract Background Ultrasound (US)‐guided hydrodissection is a minimally invasive treatment for cubital tunnel syndrome (CuTS) with promising early results. However, data on patient‐perceived outcomes, durability of relief, and impact on surgical need remain limited. Objective To assess the effectiveness of US‐guided cubital tunnel hydrodissection in improving CuTS symptoms via patient‐centered outcomes. Design Retrospective chart review with cross‐sectional telephone follow‐up. Setting Quaternary medical center multidisciplinary outpatient hand clinic. Participants Seventeen patients (19 arms) with clinical CuTS who received US‐guided hydrodissection from one physician. Interventions Patients were contacted by telephone for cross‐sectional outcome assessment. Main Outcome Measures Patient‐reported improvements in weakness, paresthesias, and/or pain, percent pain relief, symptom improvement duration, adverse events, and Patient Global Impression of Change (PGIC) scores. Results At mean 7 ± 5 month follow‐up, improvement in weakness, paresthesia, and pain was reported in 12 (63%) extremities (95% confidence interval [CI] 41%–85%; p < .001) . Pain relief ≥50% occurred in 12 (63%) and ≥75% in 8 (42%) extremities, with mean duration 4 months. PGIC scores showed 14 (74%; 95% CI 54%–94%; p < .001) at least “minimally improved” and 8 (42%) (95% CI 20%–64%; p < .001) “much improved.” No adverse events occurred. Two patients without improvement underwent surgical decompression with anterior transposition at 1 and 3 months after hydrodissection, achieving 90%–100% pain relief and “much or very much improved” PGIC scores. Of 19 extremities, 7 (37%) were McGowan Grade I and 12 (63%) Grade II; none were Grade III. Grade II extremities showed significantly greater overall symptom relief ( p = .004) and pain relief ≥50% ( p = .004). PGIC scores did not differ significantly between grades (both p > .062). Conclusion US‐guided cubital tunnel hydrodissection was associated with meaningful symptom improvement and no adverse events. Limitations include small sample size, no control group, single operator, and potentially time‐limited relief. The procedure appears safe and a potential nonoperative treatment option.

ABSTRACT Introduction/Aims Patients with cervical spinal cord injury (SCI) prioritize recovery of upper extremity function. Upper extremity reconstruction can restore function in carefully selected individuals. Infralesional cord damage, observed below the neurological level of injury (NLI), may affect postoperative outcomes. We characterized the extent of infralesional lower motor neuron (LMN) injury in patients with traumatic cervical SCI. Methods Each patient underwent electromyography (EMG) of potential donor and recipient muscles based on preoperative clinical evaluation and specific candidacy for nerve and/or tendon transfers. The presence of infralesional pathologic insertional activity (IA), reduced motor unit potential (MUP) recruitment and/or neurogenic MUPs was assessed. The caudal‐most segment with infralesional LMN injury was determined. Inclusion criteria were patients with (1) traumatic cervical SCI; (2) injury ≥ 3 months duration; (3) preoperative planning EMG for nerve and/or tendon transfers. Results Forty‐eight upper extremity EMGs in 25 patients (68% male; mean age 39.5 years at injury) with traumatic cervical SCI were included. The NLI was at C7 or above in each patient, and 64% of SCIs were motor complete. Infralesional EMG abnormalities (median time from injury to EMG 466 days) were found a median of 3.0 (IQR 3.0–4.0) segments below the NLI. Three patients with an NLI as rostral as C1–C2 exhibited LMN injury seven segments below the NLI. Discussion In persons with traumatic cervical SCI, evidence of LMN injury may be observed several segments below the NLI. Defining the true extent of LMN involvement directly informs timing and selection of reconstructive procedures to maximize functional recovery.

Background: Spasticity after upper motor neuron injury (stroke, spinal cord injury, etc.) alters muscle activity and induces long-term structural remodeling of skeletal muscle [1]. Elbow flexors, including the biceps brachii, are frequently affected, leading to abnormal tone, involuntary co-contraction, and impaired elbow function. Hyper-selective neurectomy (HSN) is a well-established surgical technique that has gained renewed clinical adoption with advances in anatomic understanding and intraoperative nerve mapping [2], yet its effects on muscle properties are poorly defined. Objective: The purpose of this study was to define pre- vs. post-HSN differences in muscle gene expression, sarcomere length, and clinical outcomes of the spastic human biceps. Methods: Individuals with elbow flexor spasticity undergoing a planned two-stage HSN were prospectively enrolled (n=10). Stage 1 released the elbow flexors and provided a pre-biopsy; Stage 2, performed ~3 months later to treat the forearm flexors, provided a second exposure to the biceps and a second biopsy. In both stages, biceps biopsies were obtained with customized clamps [3] at predefined elbow angles (50°, 90°, 135°), fixed, and analyzed for sarcomere length [4]. Total RNA was extracted from pre- and post-HSN biceps samples to characterize transcriptional changes. Clinical spasticity was assessed before Stage 1 and again before Stage 2 using the Modified Ashworth Scale (MAS). Data were compared using repeated-measures models, and single-cell transcriptional changes were analyzed using established analytical pipelines. Results: Sarcomere length (SL) increased significantly after HSN at all joint angles. At 50°, SL increased from 2.45 ± 0.18 µm pre-HSN to 3.05 ± 0.28 µm post-HSN; at 90°, from 2.70 ± 0.29 µm to 2.91 ± 0.16 µm; and at 135°, from 2.72 ± 0.36 µm to 3.24 ± 0.32 µm (all p < 0.05). Clinical spasticity assessment improved significantly as well (p < 0.05), with MAS scores decreasing from 1.89± 0.93 to 0.35 ± 0.53. RNA sequencing revealed changes in key pathways and overall gene expression patterns such as enhanced inflammatory response through increased cytokine production and fibroblast proliferation, leading to elevated collagen synthesis and subsequent fibrosis. We also observed upregulated immune modulation and chemotaxis, while pathways involved in mitochondrial respiration, muscle development, and cellular homeostasis were downregulated. At the transcript level, HSN led to decreased inflammation and adipogenesis, while promoting increased extracellular matrix assembly, and vascular formation. Conclusion: HSN produced coordinated improvements across structural, clinical, and transcriptional levels in the spastic human biceps muscle. Sarcomere lengths increased toward longer resting lengths at all joint angles, clinical spasticity decreased significantly, and RNA sequencing revealed distinct post-operative transcriptional remodeling. The longer sarcomere length and decreased spasticity should contribute to improved patient function after HSN. References: 1. Lieber RL et al. Muscle Nerve. 2002;26:98–105. 2. Leclercq C et al. Hand Clin. 2018;34:537–545. 3. Lieber RL et al. J Neurophysiol. 1994;71:874–881. 4. Ward SR et al. J Biomech. 2009;42:193–196. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Introduction: Upper limb spasticity can result from a variety of insults to the central nervous system. Disruption of the closely regulated spinal reflex arc, owing to loss of brain inhibition, results in an imbalance between antagonist and agonist muscle groups, leading to a loss of fluid coordination of motion across joints. Management strategies: A detailed, individualized assessment of each patient is mandatory in a multidisciplinary setting. Although there are objective parameters which guide treatment, variation and customization of strategies are needed for each patient, including defining a functional vs. a non-functional hand, and whether mobility or stability is the primary goal for surgery. Challenging areas in spasticity management: Surgical options include bony, tendon and nerve procedures. These aim to reduce tone, release contractures or reanimate paralysed muscles. This article examines four challenging areas in decision making for choosing these options: lengthening vs. hyperselective neurectomy for tone management, stability vs. mobility in wrist spasticity, grasp and release recovery through finger flexion and extension, and dystonia. Evidence-based treatments are discussed where available, along with key unresolved issues and future research directions. Conclusion: Restoring balance in the spastic upper limb, especially when voluntary control is lost, remains one of the most complex challenges in hand surgery. A thorough understanding of biomechanical principles and neurological pathways is necessary for the hand surgeon. Furthermore, working within a multidisciplinary team is essential to utilize a comprehensive array of assessment tools, ensuring accurate diagnosis and individualized patient care.

Background: Successful applications of artificial intelligence (AI) in healthcare have increased interest in how it could be integrated into orthopaedic surgery. However, orthopaedics surgeons’ current use of AI and attitudes toward its incorporation remain largely unexplored. The 2025 American British Canadian Travelling Fellowship Survey on AI in Orthopaedic Surgery aimed to assess AI use, knowledge, training, and attitudes among orthopaedic surgeons. Methods: The survey was administered from May 7 to September 4, 2025 to orthopaedic surgeons across Australia, New Zealand, the United Kingdom, and North America. Questions addressed demographics, AI training and use, and attitudes toward AI. Descriptive statistics summarized responses, chi-square tests compared AI use by geography and attitudes by career stage, and linear regression explored associations between demographics, AI behaviors, and outlook on AI. Results: Among 350 participants, most were trainees (45.1%) and from North America (42.9%). AI use exceeded training, and 79.9% rated their AI knowledge as average or poor. Trainees reported significantly more favorable attitudes toward AI than late-career respondents. Higher self-rated AI knowledge and AI use in clinical and research settings were associated with a more positive outlook on the future of AI in orthopaedics. Conclusions: These findings highlight the need for formal AI education, as use is widespread despite limited training, particularly among later-career surgeons. Future studies should reduce self-selection and career-stage imbalance and include additional demographic variables to improve generalizability. Level of Evidence: III . See Instructions for Authors for a complete description of levels of evidence.

» Thorough patient presurgical counseling should emphasize individual patient goals, which may include improving ambulation, reducing reliance on orthoses, alleviating pain, or facilitating caregiver support. » Careful physical examination is essential to differentiate whether the primary cause of dysfunction is weakness, spasticity, or both. » Diagnostic adjuncts including botulinum toxin, short-acting blocks, instrumented gait analysis, and dynamic electromyography provide valuable insight and guide operative decisions. » Surgical treatment must be individualized, with nerve-based procedures indicated for pure spasticity and tendon lengthening, tenotomy, or joint procedures being required to treat soft tissue and joint contractures.

Purpose Lower extremity spasticity can cause pain and limit function. This study examined the safety and efficacy of hyperselective neurectomy (HSN) of the gastrocnemius-soleus complex (GSC) in addressing spastic equinus deformities in pediatric patients. Methods Pediatric patients that underwent HSN of the GSC by a single surgeon were retrospectively reviewed. Preoperative and postoperative Modified Ashworth Score and passive ankle dorsiflexion (°) were compared using Wilcoxon signed-rank test and Student's paired two-tailed t-test, respectively. Results Ten lower extremities in seven patients with a mean age of 10 years were reviewed. Mean follow-up was 15 months. All extremities demonstrated improvement in spasticity. All exhibited improved passive ankle dorsiflexion range of motion with the knee in extension (mean change +17°, SD = 8°, p = 0.000). Five patients demonstrated improved passive dorsiflexion with the knee in flexion while two remained unchanged from preoperative assessment (mean change +13°, SD = 9°, p = 0.002). One complication, wound dehiscence, was noted and managed conservatively. No patients reported loss of strength or sensation. Four patients underwent subsequent staged surgery on the ipsilateral extremity for concomitant contractures. Conclusion HSN of the GSC is safe in pediatric patients and effectively reduces spastic equinus deformity and improves ankle passive dorsiflexion in short-term follow-up.

This study presents the first in vivo intraoperative measurement of the kinetic properties of spastic human muscle. Despite slower relaxation in spastic biceps, the force-frequency relationship was similar to that of the healthy gracilis muscle. This suggests that spasticity does not substantially alter frequency-dependent force summation, possibly due to similar fiber-type compositions and limited changes in calcium handling or myosin isoforms in human spastic muscle.

The clenched fist deformity (CFD) in adult patients with upper motor neuron syndrome (UMNS), typically due to a brain or spinal cord injury, can develop from an imbalance of the extrinsic finger flexors relative to the extensors. This brings the fingers into a flexed posture across the metacarpophalangeal (MCP) and interphalangeal (IP) joints and places the fingertips close to or in contact with the palm. The intrinsic musculature of the hand also plays a contributing role to the flexion deformity across the MCP joints whose contribution to the deformity can be masked by the extrinsic flexors. Severity of the CFD is patient specific and ranges over a spectrum dependent upon the involved muscle groups and underlying spasticity, myostatic contracture and/or joint contractures. In addition to markedly decreasing function, patients and caretakers may struggle with hygiene in the hand and even develop wounds within the palm. Surgical correction of the CFD can be classified as procedures implemented for muscles with (functional) or without (non-functional) volitional motor control. Techniques encompass muscle-tendon lengthening, tenotomies, tendon transfers, muscle origin release (slides), joint capsule and/or ligament releases. A comprehensive review of the surgical approach to correcting the CFD for the hand with and without volitional motor control in the fingers will be presented. Level of Evidence: Level V (Therapeutic)

Six patients treated by hyperselective neurectomy were assessed using preoperative dynamic electromyography and intraoperative force measurements. Patients with lower preoperative biceps dynamic electromyography activation had significantly reduced force production at operation, suggesting that these findings could guide and improve procedure selection. Level of evidence: IV