Rhee, Peter C

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.

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.

Background: Patients with upper limb dysfunction from a brain injury often have different goals of treatment and expectations following a fracture of the upper extremity. This study retrospectively reviewed outcomes of nonoperative management of acute humerus fractures in patients with severe ipsilateral hemiparesis or hemiplegia. Methods: Patients who had sustained an acute humerus fracture managed nonoperatively, greater than 1 year following an upper motor neuron (UMN) injury resulting in ipsilateral severe hemiparesis or hemiplegia at a single tertiary care center from 1988 to 2019, were reviewed. Fractures were classified using the AO-Müller/Orthopaedic Trauma Association and/or Neer classifications. Primary outcome measures included House classification level of function, pain, achievement of and time to radiographic union, and the need for subsequent surgical procedures. Results: Ten distinct nonoperatively managed humerus fractures—3 proximal (11A23), 5 mid-shaft (12A2b = 1, 12A2c = 2, 12A3a = 1, 12A2b = 1), and 2 distal (13A2 = 1, 13 C1 = 1)—were identified in 8 patients (6 women and 2 men) with ipsilateral hemiparesis or hemiplegia. The median radiographic follow-up was 20 months (range: 78 days to 12 years). The median clinical follow-up was 33.5 months (range: 100 days to 12 years). All patients presented with severe pain that was absent at final follow-up. Radiographic union was achieved in all patients with a mean time to union of 90.9 ± 39.3 days (range: 35-185 days). No patients required operative management. Conclusions: Nonoperative management of humerus fractures in patients with an ipsilateral UMN injury might result in reliable pain relief and union without the need for further surgical intervention. Management of humerus fractures in this patient population should be individualized toward their goals of care.

Background: The coronavirus disease 2019 (COVID-19) surge has enabled the widespread usage of telemedicine (TM) and presents a unique opportunity to determine the hand surgery patients’ perception of care using validated patient satisfaction scores. Methods: Electronic surveys were distributed to patients aged 18 years and older who underwent a video TM encounter with a single surgeon at an academic medical center during the initial COVID-19 surge (March 23 to October 22, 2020). The study-specific questions were derived from the Press Ganey (PG) Medical Practice TM Survey and compared with institutional PG Outpatient Medical Practice Survey data. Three cohorts were defined: pre-COVID face-to-face, post-COVID TM, and post-COVID face-to-face. Results: Thirty of 65 TM patients (46.2%) responded. No differences in sex, age, or visit type were identified between cohorts. The TM cohort was more likely to live greater than 300 miles from the institution. Median response for all cohorts for the PG care provider and overall experience responses were “very good,” and no differences were identified between cohorts. Patient satisfaction with their TM experience was high with median satisfaction scores for arranging and connecting to a TM visit, talking with the provider over a video connection, and having the provider understand the clinical problem were “very good.” Patients in the TM cohort reported no difference in preference for face-to-face or TM visits. Conclusions: Patients are satisfied with TM as a substitute for face-to-face visits suggesting that TM can possibly be used to deliver comparable patient experience for hand surgery encounters.

Background Little information exists to guide decision-making with regard to distal radius fractures in the setting of ipsilateral hemiparesis or hemiplegia. Methods Patients who sustained a distal radius fracture in the setting of ipsilateral hemiparesis or hemiplegia secondary to brain injury were evaluated. Investigated variables included perioperative pain, preinjury House functional classification score, length of immobilization, radiographic outcome measurements, and time to union. Results There were 15 patients with distal radius fractures with a mean age of 65.9 years. The mean clinical and radiographic follow-up was 2.8 and 2.9 years, respectively. Wrists were placed into the nonoperative group (NOG, n = 10) and operative group (OG, n = 5). Pain significantly decreased at final follow-up for both groups. Baseline House functional classification scores averaged 1.3 and 1.6 for the NOG and OG, respectively, and were maintained at final follow-up. Length of immobilization for the NOG was 46 days and OG was 37 days, P = .15. Radiographic outcomes at final follow-up in the NOG and OG, respectively, were a mean radial height of 9.3 versus. 11.6 mm, radial inclination of 18.3° versus 22.3°, 4.2° dorsal tilt versus 5.3° volar tilt, and tear drop angle of 45.6° versus 44.5°. There were no significant differences in these measurements. Time to radiographic union averaged 58 days for the NOG and 67 days for the OG, P = .42. There were no revision surgeries. Conclusions Based on this small case series, patients with distal radius fracture and ipsilateral hemiparesis or hemiplegia may have similar clinical, functional, and radiographic outcomes, regardless of nonoperative or operative treatment.

Background: Upper motor neuron (UMN) syndrome consists of muscle spasticity, weakness, and dyssynergy due to a brain or spinal cord injury. The purpose of this study is to describe the perioperative adverse events for adult patients undergoing single-event, multilevel upper extremity surgery (SEMLS) due to UMN syndrome. Methods: A retrospective case series was performed for 12 consecutive adult patients who underwent SEMLS to correct upper extremity dysfunction or deformity secondary to UMN syndrome. The evaluation consisted of primary outcome measures to identify readmission rates and classify adverse events that occurred within 30 days after surgery. Results: All 12 patients were functionally dependent with 50% (n = 6) men and 50% (n = 6) women at a mean age of 43.6 years (range: 21-73) with a mean of 5.92 (range: 0-16) comorbid diagnoses at the time of surgery. There were no intraoperative complications, hospital readmissions, or deaths among the 12 patients. Five patients experienced 5 minor postoperative complications that consisted of cast- or orthosis-related skin breakdown remote from the incision (n = 3), incidental surgical site hematoma that required no surveillance or intervention (n = 1), and contact dermatitis attributed to the surgical dressing that resolved with topical corticosteroids (n = 1). Conclusions: With an appropriate multidisciplinary approach, there is minimal risk for developing perioperative and 30-day postoperative adverse events for adults undergoing SEMLS to correct upper extremity deformities secondary to UMN syndrome. Level of Evidence: Level IV

Background: The scaphoid-trapezoid-trapezium (STT) articulation stabilizes the scaphoid and links the proximal and distal carpal rows. The purpose of the study was to determine whether trapezium excision in the treatment of trapeziometacarpal (TM) arthritis affects carpal stability. Methods: A retrospective chart and radiographic review was performed on all wrists that underwent trapeziectomy with suspensionplasty or ligament reconstruction, and tendon interposition for TM arthritis between 2004 and 2016. Radiographic outcome measures included the modified carpal height ratio (MCHR) and radioscaphoid (RS), radiolunate (RL), and scapholunate (SL) angles. Degenerative change at the TM and STT joints was classified according to the Eaton-Littler, and Knirk and Jupiter classification systems. Radiographic parameters were compared between preoperative and final follow-up time points. Results: A total of 122 wrists were included in the study with a mean follow-up of 3.5 years (range: 1.0-13.0 years). The mean RL (range: −2.2° ± 11.8° to −10.7° ± 16.5°) and RS angles (range: 52.6° ± 13.8° to 44.4° ± 17.8°) decreased significantly (<.001) without significant change in SL angle, indicating progressive lunate and scaphoid extension after trapeziectomy. The mean MCHR decreased significantly (range: 1.6 ± 0.1 to 1.5 ± 0.1) following trapeziectomy, indicating progressive carpal collapse. Progressive scaphoid-trapezoid arthrosis was observed following trapeziectomy. No other preoperative radiographic factors investigated were associated with significant differences in preoperative and postoperative values for radiographic outcome measures. Conclusions: Trapeziectomy can lead to loss of carpal height, coordinated extension of both the lunate and scaphoid, and progressive scaphotrapezoid arthrosis. As such, in wrists with dynamic or static carpal instability, trapeziectomy should be performed with caution due to the risk of carpal collapse with a nondissociative pattern of dorsal intercalated segment instability.

» Spasticity is the heightened motor tone that occurs as a result of damage to upper motor neurons in the central nervous system from brain or spinal cord injuries. » Nonoperative interventions for upper-extremity spasticity include chemodenervation or orthotic use, but their efficacy may be limited in correcting severe deformities. In such cases, surgical reconstruction may be necessary. » A single-event multilevel surgery (SEMLS) is a method of addressing deformities involving the entire extremity under 1 anesthetic episode. » It is the responsibility of the surgeon to assemble and communicate with the appropriate health-care team members during the patient’s hospitalization to prevent perioperative complications and to optimize outcomes after surgery. Team entities integral to successful SEMLS for patients with spasticity include respiratory therapy, nutrition, neuropalliative care, internal medicine, occupational therapy, and anesthesiology. » The goal of upper-extremity reconstruction in patients with spasticity is to improve the patient’s quality of life, reduce pain, improve hygiene, restore functionality, and correct disfiguring joint contractures.

» The surgical approach for the patient with a spastic upper limb must be individualized and goal-focused. » An injury to the central nervous system can lead to spinal reflex hyperexcitability with exaggerated muscle activation in response to quick stretch stimuli (i.e., spasticity). » Surgical treatment options are dependent on the potential for function in the spastic upper limb. » If volitional motor control is present, spastic motor units can be lengthened or released while preserving function. » In the absence of volitional motor control, spastic muscles can be divided, released, or denervated with selective neurectomies.