First-In-Human Demonstration of High Frequency Electrical Motor Nerve Block: Case Report.

ABSTRACT: This feasibility study tested the capability of high frequency stimulation (HFS) to block muscle contractions elicited by electrical stimulation of the same nerve proximally. During a tendon lengthening surgery in the forearm, the anterior interosseous nerve (AIN) was exposed. A specialized nerve cuff electrode was placed around the nerve, and a stimulating probe held on the nerve 1 cm proximal to the cuff electrode delivered pulses of current causing the pronator quadratus muscle to contract. Through the cuff electrode, 20 kHz HFS was delivered to the nerve for 10 seconds during proximal stimulation. HFS amplitudes between 5 and 10 mA peak-to-peak were tested to determine which produced complete and partial block of the electrically induced contractions. The minimum HFS amplitude that produced complete block was 8 mA, with lower amplitudes producing partial block. In all trials, muscle contractions resumed immediately after HFS was turned off. This demonstration of high frequency electrical nerve block is a milestone in the road to clinical implementation of HFS mediated motor block for spasticity.

Impact of Patient-Reported Allergies on Post-operative Complications and Healthcare Utilization Following Carpal Tunnel Release.

INTRODUCTION: Open carpal tunnel release (O-CTR) is associated with high patient satisfaction and low complication rates. Risk factors for complications are well-established. Recent studies have found that patient-reported allergies (PRAs) and psychiatric comorbidities may be associated with increased complication rates. The impact of these factors after elective hand surgery has not been evaluated. This study sought to identify whether PRAs and psychiatric comorbidities are associated with complications after O-CTR and to evaluate their association with prolonged follow-up and the need for post-operative occupational therapy (OT). METHODS: Patient demographics, PRAs, Patient Health Questionnaire-2 score, Charlson Comorbidity Index, Carpal Tunnel Symptoms-6 score, postoperative complications, OT utilization, and time to final follow-up were recorded for patients who underwent elective O-CTR between 2014 and 2022. Multivariable binomial logistic regression analysis was used to determine pre-operative variables associated with increased risk for complication. RESULTS: About 250 patients met the inclusion criteria. Fifty-one (20.4%) patients developed minor complications, including scar tenderness (N=34, 13.6%), superficial wound dehiscence (N=9, 3.6%), and superficial infection (N=8, 3.2%). There were no major complications. Independent risk factors for complications included PRAs (OR 1.80, p<0.01) and PHQ-2 score (OR 1.39, p=0.04). Five or more PRAs and PHQ-2 score ≥3 are significant independent risk factors for increased post-operative complications. Increased PRAs and PHQ-2 scores were associated with longer follow-up (p=0.01 and p<0.01, respectively) but not increased OT utilization. CONCLUSION: An increased number of PRAs and higher PHQ-2 scores are significant, independent risk factors for minor complications following O-CTR. Risk adjustment and peri-operative counseling should incorporate and account for these variables.

Clinical Outcomes of "Paralyzed" Nerve Transfer for Treating Spinal Cord Injury: A Proof of Concept in a Human Model.

Functional electrical stimulation (FES) is an option to restore function in individuals after high cervical spinal cord injury (SCI) who have limited available options for tendon or nerve transfer. To be considered for FES implantation, patients must possess upper motor neuron (UMN) type denervation in potential recipient muscles, which can be confirmed by response to surface electrical stimulation during clinical evaluation. Lower motor neuron (LMN) denervated muscles will not respond to electrical stimulation and, therefore, are unavailable for use in an FES system. Previous animal studies have demonstrated that a "paralyzed" nerve transfer of a UMN-denervated motor branch to an LMN-denervated motor branch can restore electrical excitability in the recipient. In this study, we report the indications, surgical technique, and successful outcome (restoration of M3 elbow flexion) after the first "paralyzed" nerve transfer in a human patient.

Use of Biodegradeable Temporizing Matrix Dermal Template for Reconstruction of Upper Extremity Soft Tissue Defects with Associated Tendon Injury.

In cases of complex upper extremity soft tissue defects with exposed bone or tendon, the surgeon needs to consider both restoration of stable soft tissue coverage and functional outcomes, which requires early motion and a wound bed suitable for tendon gliding. Often, local, regional, or free flaps are necessary; however, good outcomes have also been reported after staged reconstruction with a dermal template and split-thickness skin grafting. To our knowledge, staged reconstruction with a dermal template has not been described for soft tissue defects with an associated underlying tendon injury requiring tenorrhaphy. We have previously reported our experience with a synthetic dermal template [Novosorb BTM (Biodegradable Temporizing Matrix), Polynovo North America LLC. Carlsbad, Calif.] for the reconstruction of complex upper extremity defects with exposed tendon and showed that it consistently and reliably integrates even when these patients were treated with an early, active therapy protocol. As a result of these findings, we hypothesized that BTM could potentially be used over a tendon repair site without compromising functional outcomes. Here, we report on clinical outcomes for two patients with upper extremity injury where BTM was applied directly over a tendon repair or transfer site and resulted in stable soft tissue coverage with excellent tendon gliding. These early results show that this approach might be considered as an alternative to autologous tissue reconstruction in these patients and could reduce donor site morbidity associated with flap harvest.

Upper Extremity Wounds Treated with Biodegradable Temporizing Matrix versus Collagen-Chondroitin Silicone Bilayer.

Objective This study aims to compare outcomes between Novosorb Biodegradable Temporizing Matrix (BTM) and Integra collagen-chondroitin silicone for upper-extremity wound reconstruction. Methods This retrospective study analyzed adult patients who underwent wound reconstruction with either BTM or Integra at our institution between 2015 and 2020. Results Forty-eight patients were included: 31 (64.6%) BTM and 17 (35.4%) Integra. Mean age was 44.0 (range: 18-68) years. Age, race, sex, smoking, comorbidities, and defect size were similar between groups. Wound etiologies included 12 (25.0%) burn, 22 (45.8%) trauma, and others. Median template size was 133 cm 2 for BTM and 104 cm 2 for Integra ( p = 0.526). Skin grafting was performed after 14 (45.2%) and 14 (82.4%) wounds treated with BTM and Integra, respectively ( p = 0.028). Template complications of infection and dehiscence were comparable. Skin-graft complications occurred in five (35.7%) and three (21.4%) wounds in BTM and Integra, respectively ( p = 0.031). Skin-graft failure rates were comparable ( p = 0.121). Mean number of secondary procedures required after template placement was higher in the Integra group (BTM, 1.0; Integra, 1.9; p = 0.090). Final healing was achieved in 17 (54.8%) BTM and 11 (64.7%) Integra wounds ( p = 0.694). Median time to healing was 4.1 months after BTM and 2.6 months after Integra placement ( p = 0.014). Conclusion Compared with Integra, BTM achieved comparable wound healing and complication rates. Fewer secondary procedures and skin grafts were observed in BTM wounds, likely as a result of the coronavirus disease 2019 pandemic. At our institution, 100 cm 2 of product costs $850 for BTM and $3,150 for Integra, suggesting BTM as an economical alternative to fulfill the high functional and aesthetic requirements of upper-extremity wounds.

Preoperative evaluation of nerve transfer recipients after spinal cord injury using stimulated manual muscle testing.

Nerve transfer after spinal cord injury has become increasingly popular. Accurate preoperative identification of lower motor neuron involvement in potential recipient nerves is critical. Electrodiagnostic testing has been shown to correlate with intraoperative findings; however, it is time-consuming, costly and may not be readily available. Stimulated manual muscle testing is an alternative diagnostic approach. It is inexpensive and easily done by the surgeon or therapist in the office; however, correlation with intraoperative stimulation has not been reported. A retrospective review was conducted for patients who underwent nerve transfer for tetraplegia with recorded preoperative stimulated manual muscle testing and intraoperative stimulation results. Nine patients including 37 nerve transfers were included. Of the 37 nerve transfers, 36 were accurately graded preoperatively by stimulated manual muscle testing. Stimulated manual muscle testing had a sensitivity of 89%, specificity of 100%, positive predictive value of 100% and a negative predictive value of 97%. This study supports stimulated manual muscle testing for preoperative distinction between upper versus lower motor neuron injuries.Level of evidence: IV.

Tendon Transfers: Techniques to Minimize Complications.

Outcomes after tendon transfer to restore upper extremity function can be optimized using a standardized, multidisciplinary approach to the patient preoperatively, augmented intraoperative decision-making, and an early postoperative mobilization therapy protocol.

Mass-like calcific peri-arthritis in the wrist: a rare case presenting as acute carpal tunnel syndrome and requiring surgical intervention.

Hydroxyapatite deposition disease (HADD) is a common localized disorder characterized by deposition of hydroxyapatite in soft tissues. These hydroxyapatite deposits can be found in the periarticular soft tissues such as bursae, joint capsules, tendon sheaths, and ligaments as well as within the tendons themselves, and intra-articular involvement has also been described [1,2]. We present a case of a 50-year-old female with acute symptoms of carpal tunnel syndrome secondary to partially liquified, mass-like, inflammatory calcific peri-arthritis. The case is supplemented with the use of multimodality imaging, a surgical perspective, and histopathologic correlation.

An Alternative Dermal Template for Reconstruction of Complex Upper Extremity Wounds.

The management of upper extremity soft-tissue defects with full-thickness skin loss and denuded tendon and/or bone traditionally requires vascularized tissue reconstruction. Herein, we present patient outcomes utilizing Novosorb Bio-degradable Temporizing Matrix (PolyNovo, Wilmington, Del.), a novel bilaminar dermal regenerative template, followed by skin grafting, for reconstruction of complex upper extremity injuries with exposed tendon and/or bone. We retrospectively reviewed all patients treated at our Level I trauma center with upper extremity trauma and exposed tendon and/or bone who had application of Novosorb Bio-degradable Temporizing Matrix over a 1-year period. At the time of surgery, all nonviable tissue was debrided, and the product was applied according to the manufacturer's instructions. If required, split thickness skin grafting was performed once neodermis appeared perfused, or after the sealing layer delaminated spontaneously. Six patients (four men, two women) with an average age of 49.8 (35-60) years were included in the study. Average defect size measured 97 cm2 (10-440). Average time to complete healing was 45 days (27-57). Three patients reepithelialized spontaneously and did not require grafting; average defect size in these patients was 26 cm2 (10-42). There were no infections and no loss of the dermal matrix or skin graft, when performed. All patients healed without complication after grafting and did not require further surgical treatment. Therefore, we contend that Novosorb BTM is a dermal regenerative template that shows potential as an alternative option to flap reconstruction in select patients after upper extremity trauma and soft-tissue defects with exposed tendon and/or bone. Further studies will be required to refine indications and evaluate outcomes.

Reconstruction of Chronic Wounds Secondary to Injectable Drug Use with a Biodegradable Temporizing Matrix.

Injectable drug use in the upper extremity often leads to chronic wounds complicated by osteomyelitis. Conventional reconstructive options are often not feasible and/or are contraindicated in this patient population. We have started using a synthetic, biodegradable temporizing matrix (BTM) for the treatment of these patients. We hypothesize that BTM is a safe, low-risk, and low-morbidity alternative reconstructive option. We report outcomes after staged debridement and BTM application followed by split-thickness skin grafting for two patients with large, chronic bilateral forearm wounds with concomitant osteomyelitis confirmed by MRI and biopsy. No acute surgical complications were encountered and at a mean follow-up of 13 months, both patients had maintained stable soft-tissue coverage. Reconstruction using BTM is a novel treatment option that can simplify the reconstruction, reduce donor-site morbidity, and optimize success for patients with chronic wounds resulting from injectable drug use. Initial outcomes are promising; however, further comparative studies are needed to better evaluate long-term outcomes of this technique.

Psychiatric Disease after Isolated Traumatic Upper Extremity Amputation.

Introduction Psychiatric disease after traumatic limb loss impacts rehabilitation, prosthesis use, and quality of life. The purpose of this study was to evaluate the prevalence of psychiatric disease in civilians after isolated, traumatic upper extremity amputation and determine if any risk factors are associated with developing psychiatric disease. Materials and Methods Demographics, time since injury, mechanism of injury, amputation level, hand affected (dominant vs. nondominant), Bureau of Workers' Compensation (BWC) status, and prosthesis use were retrospectively reviewed for all patients treated from 2012 to 2017. For patients with an International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) diagnosed psychiatric disease, the diagnosis and length of treatment were recorded. Patients were grouped by presence or absence of psychiatric diagnosis and data analysis was performed using descriptive statistics, Fisher's exact test, and relative risk. Results Forty-six patients met the inclusion criteria. Thirty-one patients (67.4%) had at least one diagnosed psychiatric condition. Major depressive disorder was the most common ( n = 14), followed by posttraumatic stress disorder ( n = 11), adjustment disorder ( n = 11), anxiety ( n = 6), and panic disorder ( n = 2). No statistically significant correlation was seen between psychiatric illness and gender, age at the time of injury, time since injury, current employment status, BWC status, hand injured (dominant vs. nondominant), prosthetic use, or level of amputation. Conclusion The rates of depression and anxiety after traumatic upper limb loss in the civilian population are similar to reported rates after combat injury. While we were unable to identify a statistically significant association with any of the studied variables, upper extremity surgeons should be aware of the high prevalence of psychiatric disease after traumatic upper extremity amputation.

Acute compartment syndrome of the deltoid: a case report and systematic review of the literature.

BACKGROUND: Deltoid compartment syndrome is a rare entity. The purpose of this study was to report a recent case and perform a systematic literature review. METHODS: Patient data were gathered from chart review and clinical encounters. For the review, the MEDLINE, Embase, and Ovid databases were queried for deltoid compartment syndrome cases. Seventeen articles reporting on 18 patients with deltoid compartment syndrome were included. RESULTS: Including our patient, 9 of 19 patients (47.4%) presented with compartment syndrome limited to the deltoid. Most patients presented with additional affected compartments, most commonly in the ipsilateral arm (7 of 19, 37%). Isolated deltoid involvement often resulted from iatrogenic injury; of 10 iatrogenic reports, 8 involved only the deltoid. Of 19 cases, 5 (26%) occurred in powerlifters, climbers, or anabolic steroid or testosterone injectors. In 13 of 19 cases (68%), the patients were men aged 18-36 years, and only 1 female case (5%) was reported. Prolonged recumbence owing to substance abuse was documented in 6 of 19 cases (32%). CONCLUSION: Deltoid compartment syndrome is rare, with only 19 reported cases, including our patient. Men are more commonly affected, and isolated deltoid compartment syndrome occurs in about 50% of reported cases. More than half of cases are iatrogenic, secondary to prolonged lateral decubitus positioning, injections, and surgical interventions about the shoulder. Prolonged recumbence from intoxication is also a common etiology. Providers should be aware of and recognize deltoid compartment syndrome to facilitate urgent surgical management.

TMRpni: Combining Two Peripheral Nerve Management Techniques.

Amputee patients suffer high rates of chronic neuropathic pain, residual limb dysfunction, and disability. Recently, targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are 2 techniques that have been advocated for such patients, given their ability to maximize intuitive prosthetic function while also minimizing neuropathic pain, such as residual and phantom limb pain. However, there remains room to further improve outcomes for our residual limb patients and patients suffering from symptomatic end neuromas. "TMRpni" is a nerve management technique that leverages beneficial elements described for both TMR and RPNI. TMRpni involves coaptation of a sensory or mixed sensory/motor nerve to a nearby motor nerve branch (ie, a nerve transfer), as performed in traditional TMR surgeries. Additionally, the typically mismatched nerve coaptation is wrapped with an autologous free muscle graft that is akin to an RPNI. The authors herein describe the "TMRpni" technique and illustrate a case where this technique was employed.

Targeted Muscle Reinnervation for Partial Hand Amputation.

BACKGROUND: Targeted muscle reinnervation for the treatment of symptomatic neuromas after upper limb amputation has been described for shoulder disarticulation and for transhumeral and transradial amputations. Early clinical outcomes are promising and demonstrate a statistically significant reduction in phantom limb pain and a decrease in residual limb pain. METHODS: We performed a cadaver dissection of the motor branches arising from the median and ulnar nerves to assess whether this technique could be applied to symptomatic neuromas after partial hand and finger amputations. RESULTS: After identification of all branches under 4.5x loupe magnification, we performed simulated transfers of digital nerves to lumbrical motor branches, common digital nerves to lumbrical motor branches or the recurrent motor branch, and the common sensory portion of the ulnar nerve to a hypothenar motor branch. CONCLUSIONS: The proximity of all sensory nerves to motor branches and the numerous redundant motor nerve targets available support our hypothesis that targeted muscle reinnervation is possible after partial hand or finger amputation. Further studies will be required to refine clinical indications and evaluate outcomes.

Report of a Transligamentous Ulnar Nerve Sensory Branch.

Background: Several anatomical variations of the median nerve recurrent motor branch have been described. No previous reports have described the anatomical variation of the ulnar nerve with respect to transverse carpal ligament. In this article, we present a patient with symptomatic compression of the ulnar nerve found to occur outside the Guyon canal due to a transligamentous course through the distal transverse carpal ligament. Methods: A 59-year-old, right-hand-dominant male patient presented with right hand pain, subjective weakness, and numbness in both the ulnar and the median nerve distributions. Electromyography revealed moderate demyelinating sensorimotor median neuropathy at the wrist and distal ulnar sensory neuropathy. At the time of planned carpal tunnel and Guyon canal release, a transligamentous ulnar nerve sensory common branch to the fourth webspace was encountered and safely released. Results: There were no surgical complications. The patient's symptoms of numbness in the median and ulnar nerve distribution clinically improved at his first postoperative visit. Conclusions: We have identified a case of transligamentous ulnar nerve sensory branch encountered during carpal tunnel release. To our knowledge, this has not been previously reported. While the incidence of this variant is unknown, hand surgeons should be aware of this anatomical variant as its location puts it at risk of iatrogenic injury during open and endoscopic carpal tunnel release.

Fixation of a Type 3 Flexor Digitorum Avulsion Injury.

This article describes a novel technique for flexor digitorum profundus (FDP) avulsion injuries, useful for Leddy Packer type 3, 4, and 5 injuries. Multidirectional stability is achieved with combination pull-out suture, which neutralizes the deforming force of FDP, and cerclage wire, which holds the bone fragment in an anatomic position and provides interfragmentary compression. Traditional techniques such as interosseous wires, Kirschner wires, or plating risk fragment comminution and loss of reduction due to proximal pull of FDP as demonstrated in this case report of failed Kirschner-wire fixation. The technique presented here eliminates the risk of avulsion fragment comminution and provides stable fixation that allows for early mobilization.