Surgical Technique for Targeted Muscle Reinnervation in Knee Disarticulation Amputation for Nonambulatory Patients.

Chronic neuropathic pain following major limb amputation has historically been difficult to treat. In patients undergoing lower extremity amputation, "preemptive" targeted muscle reinnervation (TMR) nerve transfers may be performed concurrently with the amputation to help mitigate the risk of chronic neuropathic postoperative pain. Despite clinical studies demonstrating efficacy of TMR in lower extremity amputations, few procedural descriptions have been written, and none have been written regarding performing TMR at the knee disarticulation (KD) level of amputation. Although uncommonly utilized, the KD amputation has clear functional benefits over other levels of amputation for nonambulatory patients. As nonambulatory patients are also subject to the occurrence of chronic neuropathic postamputation pain, it stands to reason that the addition of TMR to KD surgery could be an improvement to standard techniques. In this report, we provide a technical description for concurrent TMR with KD and describe the rationale for its use.

Successful Use of Delayed Reverse Sural Artery Flap in Single Vessel Legs with Severe Atherosclerotic Disease and Venous Insufficiency.

Distal lower extremity wounds are a challenging problem for reconstructive surgeons and can lead to major lower extremity amputations in patients with comorbid conditions. The reverse sural artery flap (RSAF) is a local flap supplied by perforators of the peroneal artery that can cover defects of the distal lower extremity, ankle, and foot. There has been concern over performing the RSAF in patients with venous insufficiency, peripheral artery disease, and diabetes, and in older patients due to the increased risk of flap necrosis. In patients who are not microsurgical candidates, the RSAF may be the final option for reconstruction before undergoing major lower extremity amputation. We describe our experience with two patients with significant comorbidities and single vessel runoff from the peroneal artery due to atherosclerotic disease who successfully underwent RSAF reconstruction for distal lower extremity wounds.

Pronator Quadratus: A Preferable Recipient for Targeted Muscle Reinnervation of Neuromas in the Hand.

Targeted muscle reinnervation (TMR) has emerged as a useful solution to the problem of painful neuromas and is increasingly being applied in many clinical circumstances. Relatively little has been written about TMR for painful neuromas of the hand, and what has been written describes use of the intrinsic muscles as recipients for the nerve transfer. Except in cases of amputation, intrinsic muscle sacrifice carries morbidity. Furthermore, TMR to intrinsic muscles will place the nerve coaptation in areas subject to pressure with loading of the palm. For these reasons, the pronator quadratus may be a preferable target muscle when performing TMR for painful neuromas of the hand. In this report, we describe the rationale for its use and demonstrate the surgical technique and outcomes with case examples.

The SIEA SHRIMP Flap: An Ultrathin Axial Pattern Free Flap Useable in Obese Patients.

The reconstruction of distal extremity wounds poses a unique surgical challenge. In free tissue transfer, a thin, pliable skin flap is the ideal. Obese patients have a paucity of thin skin donor sites. Herein we report the discovery of a free SHRIMP flap (Superthin Harvest of a Reliable Islanded Medial Pannus flap) based on the SIEA vessels, harvested from a thick abdominal pannus at the time of cosmetic abdominoplasty. A 61-year-old woman with a chronic wound of the right Achilles tendon was evaluated for reconstruction after failing conservative measures. At the time of consultation, the patient expressed interest in abdominoplasty. Therefore, a skin flap from the abdomen or rectus abdominis muscle flap in the context of an abdominoplasty was offered. Despite obesity affecting the pannus, the superficial inferior epigastric vessels were found to course superficially beneath the dermis at time of abdominoplasty. This allowed straightforward harvest of a superthin flap of skin and minimal subcutaneous fat, which contoured to the ankle with an aesthetically pleasing outcome. The patient was satisfied with the results of her abdominoplasty and coverage of her chronic wound. The SHRIMP flap provides a straightforward, axial pattern, superthin free skin flap based on the superficial inferior epigastric vessels, and represents a useful option in obese patients. The flap can be combined with abdominoplasty for an aesthetic donor site.

Failed Targeted Muscle Reinnervation: Findings at Revision Surgery and Concepts for Success.

Although it was initially described for improved myoelectric control, targeted muscle reinnervation (TMR) has quickly gained popularity as a technique for neuroma control. With this rapid increase in utilization has come broadening indications and variability in the described technique. As a result, it becomes difficult to interpret published outcomes. Furthermore, there is no literature discussing the management of failed cases which are undoubtedly occurring. Methods: This is a retrospective case series of two patients who underwent revision surgery for failed TMR. The authors also review the current literature on TMR and outline technical and conceptual pitfalls and pearls based on our local experience. Results: Excessive donor nerve redundancy, kinking, donor-recipient nerve size mismatch, superficial placement of the nerve coaptation, inappropriate target selection, and incomplete target muscle denervation were identified as technical pitfalls of TMR surgery. Techniques to avoid these pitfalls were described. Conclusions: Although TMR has been a major development in amputee care for both pain management and improved myoelectric control, it is important to acknowledge that it is not a foolproof surgery and does not provide a guaranteed result. Failed cases of TMR represent opportunities to learn about factors contributing to unfavorable outcomes and refine our techniques empirically.

Cross-Sectional Evaluation of the Economic Burden on Patients Seeking Surgical Treatment for Chronic Nerve Injuries.

INTRODUCTION: Little emphasis has been paid toward characterizing the socioeconomic burdens experienced by patients seeking treatment for chronic nerve injuries. The aim of this study was to characterize the direct and indirect costs faced by patients with chronic nerve injuries and their attendant health care utilization. MATERIALS AND METHODS: A cross-sectional survey was distributed to all patients (N = 767) from a single nerve surgeon's practice treated for chronic nerve injuries in the ambulatory setting between 2014 and 2020. Data collected included demographics, etiology, comorbidities, duration and severity of symptoms, history of prior medical and interventional treatments, work or school time lost due to injury or treatment, money spent on treatment, and health care utilization. RESULTS: Of the 767 patients, 209 (27.2%) completed the survey. Average age was 48.8 (SD = 19.1) years, 68.9% female and 31.1% male. Patients with chronic nerve injury reported significant direct costs, indirect costs, and health care utilization associated with their nerve injury symptoms. Direct costs consisted of out-of-pocket spending (68.4% had spent >$1000 per year), physician specialists visits (71.3% had seen at least 4 specialists), and prior interventional procedures intended to address symptoms. Indirect costs included lost time from work or school (24.6% had missed more than 12 months). Health care utilization, represented by annual emergency room visits and hospitalizations related to nerve symptoms, was increased relative to the general population. Detailed statistics are presented in the manuscript. CONCLUSIONS: Chronic nerve injuries may be associated with a notable socioeconomic burden to the patient, including missed work or school, frequent physician visits and procedures, hospital visits, and out-of-pocket costs. Interdisciplinary algorithms recognizing a role for surgical evaluation in patients with chronic neuropathic pain due to underlying nerve injuries would facilitate future research into whether timely surgical intervention may reduce this economic burden.

Impact of Nerve Surgery on Opioid and Medication Use in Patients with Chronic Nerve Injuries.

INTRODUCTION: Limited information is available regarding the ability of nerve surgery to affect medication use patterns in patients with chronic pain or neuropathy due to nerve injury. METHODS: A retrospective survey was distributed to all operative patients (N = 767) from a single nerve surgeon's practice between 2014 and 2020. Data collected included demographics, specifics of the injury and symptoms, medication and opioid use before surgery, and medication/opioid use following surgery. RESULTS: Out of the 767 patients, 209 (27.2%) completed the survey. Average age was 48.8 (SD = 19.1) years; 68.9% female and 31.1% male. More than 50% of the patients took at least three medications. More than 50% of the patients after surgery did not need medication or had significant reduction; 54.1% of the patients took opioid medication daily, and 97.3% of patients reported that narcotic medications did not resolve their problem. Patients rated the effectiveness (Likert scale 0-10) of opioid medications in general at an average 3.25 ± 2.03. Of patients who took opioids regularly, 61.6% reported a negative effect of these medications on daily or professional activities. After surgery, more than 50% of the patients did not need opioids or had a significant reduction in opioid usage. CONCLUSIONS: Untreated nerve injuries lead to ongoing chronic pain, explaining why medications are mostly ineffective in eliminating symptoms. In this study, nerve surgery targeting the anatomical source of symptoms effectively reduced both opioid and nonopioid medication use.

Chronic Nerve Injuries and Delays in Surgical Treatment Negatively Impact Patient-reported Quality of Life.

Little emphasis has been paid to characterize quality of life (QoL) burdens experienced by patients seeking surgical treatment for nerve injuries and neuropathic pain. METHODS: A cross-sectional survey was distributed to all patients (N = 767) from a single nerve surgeon's practice between 2014 and 2019. Data collected included demographics, specifics of the injury and symptoms, time to referral, and effects of the injury, surgery, and timing of surgery on QoL. RESULTS: Of the 767 patients, 209 (27.2%) completed the survey. Average age was 48.8 years; 68.9% of patients were women and 31.1% men. At presentation, 68% had experienced symptoms for more than 1 year; 86.1% reported severity as being profound; 97.6% reported QoL was at least moderately negatively impacted by nerve injury; 70% felt they should have been referred earlier for surgical evaluation; 51.2% were not told that nerve surgery was an option for their problem; 83.1% felt that earlier referral would have improved their QoL. After surgery, symptoms were significantly mitigated in 55.5% of the patients, moderately mitigated in 21.5%. Patients reported QoL was significantly (59.8%) or at least moderately (76.6%) improved by nerve surgery. CONCLUSIONS: The majority of patients reported that nerve injuries imparted a moderate to severe impact on QoL, and that surgical treatment improved QoL. Most patients felt that earlier referral for surgical intervention would have led to better outcome and positively impacted QoL. Interdisciplinary treatment algorithms, including a role for surgical intervention, may be helpful in facilitating timely diagnosis, referral, and thus improved outcomes.

High-Frequency Alternating Current Block Using Macro-Sieve Electrodes: A Pilot Study.

Background and objective High-frequency alternating current (HFAC) can yield a rapid-acting and reversible nerve conduction block. The present study aimed to demonstrate the successful implementation of HFAC block delivery via regenerative macro-sieve electrodes (MSEs). Methods Dual-electrode assemblies in two configurations [dual macro-sieve electrode-1 (DMSE-I), DMSE-II] were fabricated from pairs of MSEs and implanted in the transected and subsequently repaired sciatic nerves of two male Lewis rats. After four months of postoperative nerve regeneration through the MSEs' transit zones, the efficacy of acute HFAC block was tested for both configurations. Frequencies ranging from 10 kHz to 42 kHz, and stimulus amplitudes with peak-to-peak voltages ranging from 2 V to 20 V were tested. Evoked muscle force measurement was used to quantify the nerve conduction block. Results HFAC stimulation delivered via DMSE assemblies obtained a complete block at frequencies of 14 to 26 kHz and stimulus amplitudes of 12 to 20 V p-p. The threshold voltage for the complete block showed an approximately linear dependence on frequency. The threshold voltage for the partial conduction block was also approximately linear. For those frequencies that displayed both partial and complete block, the partial block thresholds were consistently lower. Conclusion This study provides a proof of concept that regenerative MSEs can achieve complete and reversible conduction block via HFAC stimulation of regenerated nerve tissue. A chronically interfaced DMSE assembly may thereby facilitate the inactivation of targeted nerves in cases wherein pathologic neuronal hyperactivity is involved.

Translating Technique into Outcomes in Amputation Surgeries.

The department of surgery at Washington University is putting increased emphasis on outcomes for amputees. This multidisciplinary effort begins with choosing the correct surgery and incorporating the latest technical advances in amputation surgery.

Reconstruction of Severe Palm Injury with Sensate Medial Plantar Artery Flap and Nerve Grafting.

A 28-year-old, healthy man presented with an abrasion injury of the left palm, including a full-thickness glabrous skin defect, an open injury of the carpal tunnel with 50% transection of the median nerve, and a multilevel traction/avulsion injury of the thenar motor branch. He underwent repair with a free medial plantar artery flap, nerve transfer of the palmar cutaneous nerve to the medial plantar cutaneous nerve, grafting of the median nerve, and direct neurotization of the thenar muscles via an end-to-side nerve graft from the median nerve. At 8 months postoperative, both donor and recipient areas had healed completely, and the patient had regained meaningful 2-point discrimination of the palm and fingers, achieved innervation of the thenar muscles, and returned to work as a cook.

Surgical Technique for Below-knee Amputation with Concurrent Targeted Muscle Reinnervation.

Targeted muscle reinnervation (TMR) is beneficial for decreasing pain following below-knee amputation (BKA). While most current literature describes the principles behind primary TMR, they provide few principles key to the amputation, as the BKA is usually performed by another surgeon. When the BKA and TMR are performed by the same surgeon, it can be performed through the same surgical access as needed for both procedures. The purpose of this article is to describe our anatomically based BKA technique in the setting of planned primary TMR as performed by 3, single, peripheral nerve plastic surgeons at 2 institutions. Advantages of the single-surgeon technique include efficiency in dissection, preservation of donor nerve length, limited proximal dissection, early identification of recipient motor nerves for coaptation, ability to stimulate these while still under tourniquet, and decreased tourniquet and operative time. This technique is quick, reliable, and reproducible to help promote widespread adoption of TMR at the time of BKA.

Foot Salvage with Selective Arterialization of Pedal Venosomes.

BACKGROUND: Lower extremity salvage using microvascular flaps can be considered in high-functioning patients, but indications for salvage are often restricted by distal microvascular disease that may threaten the foot as a whole. Selective arterialization of specific pedal venosomes is a novel potential solution to this problem. METHODS: A 48-year-old man with a chronic left plantar forefoot wound, osteomyelitis of the second and third metatarsal heads, and critical limb ischemia was evaluated for foot salvage. Despite a patent popliteal to posterior tibial bypass graft, residual ischemia was present in the first and second toes due to severe microvascular disease. This wound was reconstructed with a free partial medial rectus abdominis flow-through flap based on the medial branch of the deep inferior epigastric artery. The lateral branch was used as a flow-through vessel to arterialize the dorsal veins of the first webspace. RESULTS: Arterialization of the first webspace veins resulted in an immediate intraoperative improvement of the color of the first and second toes, along with creation of an arterial Doppler signal. The flap effectively covered the wound. The patient went on to heal completely and return to unrestricted ambulation. Transcutaneous oxygen measurement values of the dorsal foot improved from 35.8 mm Hg preoperatively to 48.3 mm Hg postoperatively. CONCLUSIONS: In patients with focal areas of critical ischemia, selective arterialization of the venous system may be an effective method of preventing tissue loss and improving wound healing. A flow-through flap can be used to accomplish this in tandem with wound reconstruction.

Cross-Palm Nerve Grafts to Enhance Sensory Recovery in Severe Ulnar Neuropathy.

Background: Intrinsic atrophy and debilitating sensory loss are prominent features of severe ulnar neuropathy with limited surgical options to reliably improve recovery. Restoration of sensation is important to provide protection for the vulnerable ulnar border of the hand. Here, we report our experience with side-to-side sensory nerve grafting from the median to ulnar nerve in the palm to enhance ulnar sensory recovery. Methods: A retrospective chart review identified patients with severe ulnar neuropathy who underwent cross-palm nerve grafting. Included patients had objective loss of protective sensation in the ulnar distribution with 2-point discrimination >8 mm, Semmes-Weinstein monofilament testing (SWMT) >4.56, or no sensory response on nerve conduction testing. Cross-palm side-to-side tension-free grafting from median to ulnar sensory components was performed using short-segment allograft or autografts. Analysis included patient etiology, procedures, nerve conduction studies, objective sensory testing, and Disabilities of the Arm, Shoulder, and Hand Disability score. Results: Forty-eight patients with severe ulnar neuropathy underwent cross-palm nerve grafting between 2014 and 2017. Twenty-four patients had adequate follow-up for inclusion. Of the 24 patients, 21 (87%) had return of protective sensation, 16 (66.7%) had return of diminished light touch sensation, and 6 (25%) had return to normal range sensation within 1 year as assessed by SWMT and/or 2-point discrimination. Patients treated with autograft demonstrated referred sensation to the median nerve distribution. Conclusions: Cross-palm nerve grafting may be a useful adjunct to enhance sensory recovery in severe ulnar neuropathy. Further study to quantify differences in sensory recovery between traditional operative techniques and cross-palm nerve grafting is required.

Median Neuropathy After Blood Draw Mimics Painful Clenched Fist Syndrome in a Child.

Background: Clenched fist syndrome is a rare disorder, often attributed to a conversion disorder without anatomic basis. Here, we review the literature surrounding clenched fist syndrome and challenge the assumption it is always psychiatric in origin, via description of a case of clenched fist syndrome responsive to surgical nerve decompression. Methods: An unusual case of clenched fist syndrome is reviewed and discussed. Results: A child presenting with clenched fist syndrome failed conservative measures consisting of formal hand therapy, multidisciplinary pain management, and psychiatric treatment. On clinical examination, she had findings consistent with median nerve entrapment. After undergoing surgical decompression of the median nerve in the forearm and carpal tunnel, the clenched fist resolved immediately. Conclusions: Nerve compression may be an unrecognized factor underlying some cases of clenched fist syndrome. Evaluation by a hand surgeon or a hand therapist skilled in the detection of peripheral nerve entrapment or injury should be considered as part of the workup for this rare disorder.

The 7 Structures Distal to the Elbow That Are Critical to Successful Anterior Transposition of the Ulnar Nerve.

Background: Ulnar nerve transposition (UNT) surgery is performed for the treatment of cubital tunnel syndrome. Improperly performed UNT can create iatrogenic pain and neuropathy. The aim of this study is to identify anatomical structures distal to the medial epicondyle that should be recognized by all surgeons performing UNT to prevent postoperative neuropathy. Methods: Ten cadaveric specimens were dissected with attention to the ulnar nerve. Intramuscular UNT surgery was simulated in each. Distal to the medial epicondyle, any anatomical structure prohibiting transposition of the ulnar nerve to a straight-line course across the flexor-pronator mass was noted and its distance from the medial epicondyle was measured. Results: Seven structures were found distal to the medial epicondyle whose recognition is critical to ensuring a successful anterior transposition of the ulnar nerve: (1) Branches of the medial antebrachial cutaneous (MABC) nerve; (2) Osborne's fascia; (3) branches from the ulnar nerve to the flexor carpi ulnaris (FCU); (4) crossing vascular branches from the ulnar artery to the FCU; (5) the distal medial intermuscular septum between the FCU and flexor digitorum superficialis (FDS); (6) the combined muscular origins of the flexor-pronator muscles; and (7) the investing fascia of the FDS. Measurements are given for each structure. Conclusions: Poor outcomes and unnecessary revision surgeries for cubital tunnel syndrome can be avoided with intraoperative attention to 7 structures distal to the medial epicondyle. Surgeons should expect to dissect up to 12 cm distal to the medial epicondyle to adequately address these and prevent kinking of the nerve in transposition.

Surgical and Clinical Decision Making in Isolated Long Thoracic Nerve Palsy.

BACKGROUND: Isolated long thoracic nerve palsy results in scapular winging and destabilization. In this study, we review the surgical management of isolated long thoracic nerve palsy and suggest a surgical technique and treatment algorithm to simplify management. METHODS: In total, 19 patients who required surgery for an isolated long thoracic nerve palsy were reviewed retrospectively. Preoperative demographics, electromyography (EMG), and physical examinations were reviewed. Intraoperative nerve stimulation, surgical decision making, and postoperative outcomes were reviewed. RESULTS: In total, 19 patients with an average age of 32 were included in the study. All patients had an isolated long thoracic nerve palsy caused by either an injury (58%), Parsonage-Turner syndrome (32%), or shoulder surgery (10%); 18 patients (95%) underwent preoperative EMG; 10 with evidence of denervation (56%); and 13 patients had motor unit potentials in the serratus anterior (72%). The preoperative EMG did not correlate with intraoperative nerve stimulation in 13 patients (72%) and did correlate in 5 patients (28%); 3 patients had a nerve transfer (3 thoracodorsal to long thoracic at lateral chest, 1 pec to long thoracic at supraclavicular incision). In the 3 patients who had a nerve transfer, there was return of full forward flexion of the shoulder at an average of 2.5 months. CONCLUSIONS: A treatment algorithm based on intraoperative nerve stimulation will help guide surgeons in their clinical decision making in patients with isolated long thoracic nerve palsy. Intraoperative nerve stimulation is the gold standard in the management of isolated long thoracic nerve palsy.