Shin, Alexander Y.

» Iatrogenic nerve injuries may occur after any intervention of the upper extremity. » Causes of iatrogenic nerve lesions include direct sharp or thermal injury, retraction, compression from implants or compartment syndrome, injection, patient positioning, radiation, and cast/splint application, among others. » Optimal treatment of iatrogenic peripheral nerve lesions relies on early and accurate diagnosis. » Advanced imaging modalities (e.g., ultrasound and magnetic resonance imaging) and electrodiagnostic studies aid and assist in preoperative planning. » Optimal treatment of iatrogenic injuries is situation-dependent and depends on the feasibility of direct repair, grafting, and functional transfers.

Abstract Background Concomitant severe radiocarpal (RC) arthritis with asymptomatic or minimally symptomatic distal radioulnar joint (DRUJ) arthritis can be debilitating for patients. Surgical management of these combined arthritides can pose a dilemma for surgeons and patients. The purpose of this study was to evaluate patients with concomitant RC and DRUJ arthritides who underwent only total wrist arthrodesis (TWA) to determine the need for subsequent surgical management of preoperative asymptomatic/minimally symptomatic DRUJ arthritis. Materials and Methods All patients who underwent TWA between 2008 and 2018 at a single institution were evaluated. Those patients who underwent TWA for degenerative, inflammatory, or posttraumatic arthritis with concomitant asymptomatic or minimally symptomatic DRUJ arthritis preoperatively were included. A retrospective review was performed for demographic variables, TWA indications, pre- versus post-TWA DRUJ symptoms, and severity of DRUJ arthritis on radiographs. Primary outcome measure was survivorship from subsequent DRUJ surgery for development of symptomatic arthritis after initial TWA. Results One hundred and eighty-three patients underwent TWA during the study period, of which 39 wrists met inclusion criteria. Indications for TWA included posttraumatic arthritis (n = 22), avascular necrosis of the lunate (n = 10), and inflammatory arthritis (n = 7). The mean clinical follow-up was 5.7 years (range: 1.5–12.7 years). Four patients (10%) who underwent TWA ultimately required a subsequent procedure to address DRUJ arthritis at a mean time of 20 months (range: 3–60 months) after initial TWA. The initial indication for TWA in these patients included symptomatic posttraumatic arthritis (n = 3) and lunate avascular necrosis (n = 1). Conclusion In patients with symptomatic RC and asymptomatic or minimally symptomatic DRUJ arthritides undergoing TWA alone, 10% in this series required subsequent surgical management for progressive DRUJ arthritis. Clinical Relevance Surgical management of concomitant symptomatic RC and asymptomatic/minimally symptomatic DRUJ arthritides with TWA alone is a reasonable initial approach. Patients should be counseled preoperatively that subsequent surgical management of progressive DRUJ arthritis may be necessary in ∼10% of patients.

Purpose of the Review: Traumatic brachial plexus injuries (BPI) are devastating life-altering events, with pervasive detrimental effects on a patient's physical, psychosocial, mental, and financial well-being. This review provides an understanding of the clinical evaluation, surgical indications, and available reconstructive options to allow for the best possible functional outcomes for patients with BPI. Recent Findings: The successful management of patients with BPI requires a multidisciplinary team approach including peripheral nerve surgeons, neurology, hand therapy, physical therapy, pain management, social work, and mental health. The initial diagnosis includes a detailed history, comprehensive physical examination, and critical review of imaging and electrodiagnostic studies. Surgical reconstruction depends on the timing of presentation and specific injury pattern. A full spectrum of techniques including neurolysis, nerve grafting, nerve transfers, free functional muscle transfers, tendon transfers, and joint arthrodesis are utilized. Summary: Despite the devastating nature of BPI injuries, comprehensive care within a multidisciplinary team, open and practical discussions with patients about realistic expectations, and thoughtful reconstructive planning can provide patients with meaningful recovery.

Background: A variety of approaches have been described to obtain rudimentary grasp after traumatic pan-brachial plexus injury in adults. The aim of this study is to evaluate hand prehension after a gracilis single-stage free functioning muscle transfer. Methods: Twenty-seven patients who underwent gracilis single-stage free functioning muscle transfer for elbow flexion and hand prehension after a pan-plexus injury were included. All patients presented with a minimum of 2 years of follow-up. Postoperative finger flexion, elbow flexion strength, preoperative and postoperative Disability of the Arm, Shoulder, and Hand questionnaire scores, secondary hand procedures, complications, and demographic characteristics were analyzed. Results: Twenty patients (74%) demonstrated active finger pull-through. Only six patients (25%) considered their hand function useful for daily activities. Disability of the Arm, Shoulder, and Hand score improved by 13.1 ± 13.7 (P < 0.005). All patients were expected to require one secondary procedure (wrist fusion, thumb carpometacarpal fusion, and/or thumb interphalangeal fusion) because no extensor reconstruction was performed. These were performed in 89%, 78%, and 74% of patients, respectively. Four postoperative complications (hematoma, seroma, wound dehiscence, and skin paddle loss) occurred. No flap loss occurred. Conclusions: In pan-plexus injuries, the use of a gracilis single-stage free functioning muscle transfer is an alternative to the double free functioning muscle transfer procedure and contralateral C7 transfer, especially for patients who are unable to undergo two to three important operations in a short period of time. Further research and studies are required to improve hand function in these patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Case: A patient with prior left-sided brachial plexus trauma and associated left phrenic nerve paralysis subsequently developed transient respiratory failure after a contralateral supraclavicular nerve block. Her known left phrenic nerve palsy secondary to her index brachial plexus injury was rediscovered during the workup of her acute respiratory distress, which resulted in an emergent intensive care unit admission. Conclusion: The paralysis of her right phrenic nerve at the time of left-sided regional anesthesia was identified as the etiology of near-complete bilateral diaphragmatic paralysis and respiratory failure.

Case: A 34-year-old farmer and railroad worker injured his left wrist when working at a railroad. The resulting dorsal-ulnar wrist blow caused disabling pain. Splits and 2 subsequent surgeries failed, including an arthroscopic triangular fibrocartilage complex (TFCC) debridement and thermal ablation. Subsequently, magnetic resonance imaging documented a rare Palmer type 1C distal TFCC avulsion. Function was restored and return to farming permitted by reconstruction of the ulnotriquetral (UT) ligament using an extensor carpi ulnaris (ECU) slip. Conclusion: Chronic Palmer type 1C TFCC injuries can be successfully treated with ECU reconstruction of the UT ligament.

AbstractSegmental bone defects are often performed with cryopreserved allografts. They provide immediate stability, but risk nonunion, infection and late stress fracture. Improving the rate and extent of bone revitalization may improve results. Angiogenesis from surgically placed arteriovenous (AV) bundles improves bone blood flow and vitality in cryopreserved rat femora, augmented by vasculogenic growth factors. This study tests the same principal in Yucatan mini‐pigs with a tibial diaphyseal defect, combining surgical angiogenesis with angiogenic gene therapy within cryopreserved orthotopically‐placed allografts. Tibial diaphyseal defects were reconstructed with cryopreserved allografts and rigid internal fixation in 16 mini pigs. Half of the cranial tibial AV bundles placed within the allograft medullary canal were transfected with an adeno‐associated virus containing vascular endothelial growth factor (VEGF) and platelet‐derived growth factor (PDGF) genes (AAV9.VEGF.PDGF). Bone remodeling, angiogenesis, and allograft healing were assessed. During the postoperative survival period 5 of 8 transfected animals developed cutaneous benign vascular lesions at sites remote from the operated hindlimb, causing excessive bleeding. Within the allograft, both medullary (p = 0.013) and cortical (p = 0.009) vascular volumes were higher and vessels more mature than nontransfected allografts. Bone turnover (p = 0.013), bone mineralization (p = 0.018), bone healing (p = 0.008) and graft incorporation (p = 0.006) were all significantly higher in the gene therapy group. In a large animal tibial defect model, gene therapy of implanted AV bundles improved revascularization, remodeling and healing of cryopreserved allografts used for limb reconstruction. However, benign vascular lesions causing excessive bleeding developed in 5 out of 8 pigs transfected with AAV containing genes for VEGF and PDGF. This unforeseen complication makes vasculogenic gene therapy unacceptable for clinical use.

AbstractIntroductionCarpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Although prior studies have explored the anatomic changes of the median nerve and carpal arch with different wrist deviations and positionings, the change in safe zone distance between the median nerve and ulnar artery with ulnar or radial wrist deviations has not been adequately investigated.ObjectiveTo identify the optimal wrist positioning that increases the safe zone distance between the median nerve and ulnar artery using ultrasound in patients with CTS.DesignRetrospective cohort study.SettingQuaternary medical center multidisciplinary outpatient hand clinic.ParticipantsTwenty five patients (41 wrists) with clinical CTS who received an electrodiagnostic study (EDX) to evaluate CTS within 1 year prior to enrollment.InterventionsUltrasound‐identified safe zone distance measurements were obtained in each patient between the ulnar aspect of the median nerve and the radial aspect of the ulnar artery with the wrist in neutral radial‐ulnar deviation as well as in passive ulnar and radial deviation.Main Outcome MeasureThe ultrasound‐identified safe zone distance with the wrist in each of the three positions.ResultsThe interstructural safe zone distance was significantly greater when measured in the ulnarly deviated position (1.08 cm) compared with either the neutral (0.61cm, p < .001) or radially deviated positions (0.52 cm, p < .001). Interstructural safe zone distance did not differ between those with normal, mild, moderate, or severe classifications of pathology, or between dominant and nondominant limbs.ConclusionThis study demonstrates that the ultrasound‐measured interstructural safe zone distance was significantly greater in the ulnarly deviated position than in either the neutral position or radially deviated position. These findings may lead to improvement in the safety of ultrasound‐guided injections.

Abstract Introduction/Aims Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure‐palsies (HNPP) and Charcot–Marie‐Tooth type 1A (CMT1A) and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients. Methods Medical records were reviewed for patients with PMP22 mutations confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression. Results CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10‐HNPP and 5‐CMT1A patients, and CuTS decompression with/without transposition was performed in 5‐HNPP and 1‐CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at the carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity‐provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio = 117.0:95% confidence interval, 1.94 > 999.99, p = 0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened. Discussion CTS symptom improvement post‐surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity‐provoked symptoms in HNPP best informed benefits from CTS surgery.