Experience with ultrasound neurography for postoperative evaluation of targeted muscle reinnervation.

Targeted muscle reinnervation (TMR) was originally developed as a means for increasing intuitive prosthesis control, though later found to play a role in phantom limb pain and neuroma prevention. There is a paucity of literature describing the clinical course of patients with poor TMR surgical outcomes and the value of imaging in the postoperative recovery period. This report will illustrate the potential utility of ultrasound neurography to accurately differentiate TMR surgical outcomes in two patients that received upper extremity amputation and subsequent reconstruction with TMR. Ultrasound evaluation of TMR sites in patient 1 confirmed successful reinnervation, evident by nerve fascicle continuity and eventual integration of the transferred nerve into the target muscle. Conversely, the ultrasound of patient 2 showed discontinuity of the nerve fascicles, neuroma formation, and muscle atrophy in all three sites of nerve transfer, suggesting an unsuccessful procedure and poor functional recovery. Ultrasound neurography is uniquely able to capture the longitudinal trajectory of rerouted nerves to confirm continuity and eventual reinnervation into muscle. Therefore, the application of ultrasound in a postoperative setting can correctly identify instances of failed TMR before this information would become available through clinical evaluation. Early identification of poor TMR outcomes may benefit future patients by fostering the discovery of failure mechanisms and aiding in further surgical planning to improve functional outcomes.

The Current State of Targeted Muscle Reinnervation: A Systematic Review.

BACKGROUND: Targeted muscle reinnervation (TMR) is growing in popularity; however, literature evaluating patient characteristics and outcomes is limited. METHODS: The EMBASE database was queried with the search terms "targeted muscle reinnervation" OR "TMR" AND "outcomes" OR "patient outcomes." Clinical human studies in English were eligible for inclusion, yielding 89 articles. After rigorous exclusion criteria, a total of 13 articles were included in this review. Study data including geographic location, patient demographics, TMR indication, amputation level, number of nerve transfers performed, length of follow-up, and reported outcomes were extracted and analyzed. RESULTS: The included articles represent 338 patients (341 limbs). Average patient age was 47.4 years. Indication for amputation included trauma (n = 125), infection (n = 76) cancer/tumor resection (n = 71), ischemia (n = 18), failed Charcot reconstruction (n = 15), failed hardware (n = 9), burn (n = 4), and CRPS (n = 4). Five studies included upper extremity TMR only, two included lower extremity TMR only, and six included both upper and lower extremity TMR. TMR was performed in an immediate or delayed fashion, with an average of 2.2 nerve transfers performed per limb overall. Average length of follow-up was 22.3 months. In three studies, patients with phantom limb pain undergoing delayed TMR were found to have significant or trending toward significant reduction in pain after TMR using numeric rating scale and patient-reported outcomes measurement information system scales. One article reported 9/10 patients with improved or complete resolution of phantom limb pain after delayed TMR. Three studies found that patients undergoing immediate TMR had lower pain scores compared with non-TMR controls. CONCLUSION: While there is evidence that TMR reduces neuroma-related pain and improves the quality of life for amputees, further outcomes studies are needed to study the patient experience with TMR on a larger scale. Establishing standardized, validated patient-reported outcomes assessment tools is critical to future investigation in this field.

Complex regional pain syndrome patient treated with a below knee amputation, implanting nerves directly into muscle: A case report.

Persistent, disabling lower extremity pain, outside the distribution of a single nerve, is termed chronic regional pain syndrome (CRPS), but, in reality, this chronic pain is often due to multiple peripheral nerve injuries. It is the purpose of this report to describe the first application of the "traditional," nerve implantation into muscle, usually used in the treatment of a painful neuroma, as a pre-emptive surgical technique in doing a below knee amputation (BKA). In 2011, a 51-year-old woman developed severe, disabling CRPS, after a series of operations to treat an enchondroma of the left fifth metatarsal. When appropriate peripheral nerve surgeries failed to relieve distal pain, a BKA was elected. The approach to the BKA included implantation of each transected peripheral nerve directly into an adjacent muscle. At 5.0 years after the patient's BKA, the woman reported full use of this extremity, using the prosthesis, and was free of phantom limb and residual limb pain. This anecdotal experience gives insight that long-term relief of lower extremity CRPS can be achieved by a traditional BKA utilizing the approach of implanting each transected nerve into an adjacent muscle.

[Targeted muscle reinnervation and targeted sensory reinnervation : Role of complex neurotization after amputation]. / "Targeted muscle reinnervation" und "targeted sensory reinnervation" : Rolle komplexer Neurotisationen nach Amputation.

In association with major amputations of the upper and lower extremities, surgical procedures with nerve transfer are increasingly being introduced. In order to examine the value of these procedures the currently available data were analyzed and related to the corresponding insights from conventional amputation surgery as well as confirmed aspects of microsurgery of peripheral nerves. Mainly retrospective observations of low case numbers and sometimes individually different surgical approaches can be found. Risk analysis and sufficient long-term follow-up periods are lacking as well as comparisons with appropriate control groups. The published results on operative procedures with selected nerve transfers after or during amputation do not currently allow any conclusions about the advantages. Systematic influences in the assessment of the results are probable. Implementation of these treatment options outside controlled clinical trials cannot be recommended.

Targeted Muscle Reinnervation Improves Residual Limb Pain, Phantom Limb Pain, and Limb Function: A Prospective Study of 33 Major Limb Amputees.

BACKGROUND: Targeted muscle reinnervation is an emerging surgical technique to treat neuroma pain whereby sensory and mixed motor nerves are transferred to nearby redundant motor nerve branches. In a recent randomized controlled trial, targeted muscle reinnervation was recently shown to reduce postamputation pain relative to conventional neuroma excision and muscle burying. QUESTIONS/PURPOSES: (1) Does targeted muscle reinnervation improve residual limb pain and phantom limb pain in the period before surgery to 1 year after surgery? (2) Does targeted muscle reinnervation improve Patient-reported Outcome Measurement System (PROMIS) pain intensity and pain interference scores at 1 year after surgery? (3) After 1 year, does targeted muscle reinnervation improve functional outcome scores (Orthotics Prosthetics User Survey [OPUS] with Rasch conversion and Neuro-Quality of Life [Neuro-QOL])? METHODS: Data on patients who were ineligible for randomization or declined to be randomized and underwent targeted muscle reinnervation for pain were gathered for the present analysis. Data were collected prospectively from 2013 to 2017. Forty-three patients were enrolled in the study, 10 of whom lacked 1-year follow-up, leaving 33 patients for analysis. The primary outcomes measured were the difference in residual limb and phantom limb pain before and 1 year after surgery, assessed by an 11-point numerical rating scale (NRS). Secondary outcomes were change in PROMIS pain measures and change in limb function, assessed by the OPUS Rasch for upper limbs and Neuro-QOL for lower limbs before and 1 year after surgery. RESULTS: By 1 year after targeted muscle reinnervation, NRS scores for residual limb pain from 6.4 ± 2.6 to 3.6 ± 2.2 (mean difference -2.7 [95% CI -4.2 to -1.3]; p < 0.001) and phantom limb pain decreased from 6.0 ± 3.1 to 3.6 ± 2.9 (mean difference -2.4 [95% CI -3.8 to -0.9]; p < 0.001). PROMIS pain intensity and pain interference scores improved with respect to residual limb and phantom limb pain (residual limb pain intensity: 53.4 ± 9.7 to 44.4 ± 7.9, mean difference -9.0 [95% CI -14.0 to -4.0]; residual limb pain interference: 60.4 ± 9.3 to 51.7 ± 8.2, mean difference -8.7 [95% CI -13.1 to -4.4]; phantom limb pain intensity: 49.3 ± 10.4 to 43.2 ± 9.3, mean difference -6.1 [95% CI -11.3 to -0.9]; phantom limb pain interference: 57.7 ± 10.4 to 50.8 ± 9.8, mean difference -6.9 [95% CI -12.1 to -1.7]; p ≤ 0.012 for all comparisons). On functional assessment, OPUS Rasch scores improved from 53.7 ± 3.4 to 56.4 ± 3.7 (mean difference +2.7 [95% CI 2.3 to 3.2]; p < 0.001) and Neuro-QOL scores improved from 32.9 ± 1.5 to 35.2 ± 1.6 (mean difference +2.3 [95% CI 1.8 to 2.9]; p < 0.001). CONCLUSIONS: Targeted muscle reinnervation demonstrates improvement in residual limb and phantom limb pain parameters in major limb amputees. It should be considered as a first-line surgical treatment option for chronic amputation-related pain in patients with major limb amputations. Additional investigation into the effect on function and quality of life should be performed. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Targeted Muscle Reinnervation in the Hand: Treatment and Prevention of Pain After Ray Amputation.

Targeted muscle reinnervation (TMR), originally developed as an experimental technique for prosthetic control, has been shown to be safe and effective for the treatment and prevention of postamputation pain. Targeted muscle reinnervation involves coaptation of residual nerve ends to nearby motor nerve branches of healthy but expendable muscles proximal to an amputation. It has been shown to prevent and reduce residual limb pain and phantom limb pain after major upper and lower extremity amputation. However, the use of this technique has not been described distal to the forearm because bioprosthetic use is not a consideration at that level. The aim of this article was to (1) present 2 cases of TMR performed in the setting of ray amputation, and (2) provide technical strategies for maximizing success and efficiency.

Targeted Muscle Reinnervation: Outcomes in Treating Chronic Pain Secondary to Extremity Amputation and Phantom Limb Syndrome.

BACKGROUND: Secondary to vascular disease, oncological resection, or devastating trauma, lower extremity amputations are performed globally at a yearly rate exceeding 1 million patients. Three-quarters of these patients will develop chronic pain or phantom pain, which presents a functional limitation for prosthetic use and contributes to deconditioning and increased mortality. Targeted muscle reinnervation (TMR) presents a surgical solution to this problem as either a primary or secondary intervention. METHODS: A review of the existing literature was conducted using a combination of the terms "phantom pain" "chronic pain," "neuroma," and "targeted muscle reinnervation" in Medline and PubMed. RESULTS: Five articles were found which addressed TMR for pain syndromes, four of which involved lower extremity amputation. Four of the articles were retrospective reviews, and one was a randomized control trial. A total of 149 patients were included, of which 82 underwent lower extremity amputation. Ninety-two of the patients underwent prophylactic TMR, of which 57 were secondary procedures.In patients who underwent TMR at the time of amputation, all studies reported a minimal development of symptomatic neuromas (27%). For secondary TMR, near-complete resolution of previous pain was found (90%). Phantom pain was noted to be similar to other studies in the literature but noted to improve over time with both primary (average drop of 3.5 out of 10 points on the numerical rating scale) and secondary (diminishing from 72% of patients to 13% over 6 months) operations. CONCLUSION: Although much of the current literature is limited to retrospective studies with few patients, these data point toward near-complete resolution of neuroma pain after treatment as well as complete prevention of chronic pain if TMR is used as a prophylactic measure during the index amputation. THIS STUDY WAS A LEVEL OF EVIDENCE IV: .

Targeted Muscle Reinnervation Treats Neuroma and Phantom Pain in Major Limb Amputees: A Randomized Clinical Trial.

OBJECTIVE: To compare targeted muscle reinnervation (TMR) to "standard treatment" of neuroma excision and burying into muscle for postamputation pain. SUMMARY BACKGROUND DATA: To date, no intervention is consistently effective for neuroma-related residual limb or phantom limb pain (PLP). TMR is a nerve transfer procedure developed for prosthesis control, incidentally found to improve postamputation pain. METHODS: A prospective, randomized clinical trial was conducted. 28 amputees with chronic pain were assigned to standard treatment or TMR. Primary outcome was change between pre- and postoperative numerical rating scale (NRS, 0-10) pain scores for residual limb pain and PLP at 1 year. Secondary outcomes included NRS for all patients at final follow-up, PROMIS pain scales, neuroma size, and patient function. RESULTS: In intention-to-treat analysis, changes in PLP scores at 1 year were 3.2 versus -0.2 (difference 3.4, adjusted confidence interval (aCI) -0.1 to 6.9, adjusted P = 0.06) for TMR and standard treatment, respectively. Changes in residual limb pain scores were 2.9 versus 0.9 (difference 1.9, aCI -0.5 to 4.4, P = 0.15). In longitudinal mixed model analysis, difference in change scores for PLP was significantly greater in the TMR group compared with standard treatment [mean (aCI) = 3.5 (0.6, 6.3), P = 0.03]. Reduction in residual limb pain was favorable for TMR (P = 0.10). At longest follow-up, including 3 crossover patients, results favored TMR over standard treatment. CONCLUSIONS: In this first surgical RCT for the treatment of postamputation pain in major limb amputees, TMR improved PLP and trended toward improved residual limb pain compared with conventional neurectomy. TRIAL REGISTRATION: NCT02205385 at ClinicalTrials.gov.

Targeted muscle reinnervation and prosthetic rehabilitation after limb loss.

Over one million amputations occur annually world-wide. Often, amputation of the neoplastic limb is regarded as a surgical failure and the end of surgical care for the patient. Here, we highlight the advancements in extremity prostheses and surgical techniques that should change that mindset. Myoelectric prostheses, osseointegration, and targeted muscle reinnervation allow for more intuitive and easy to use devices, reduced pain, and greater quality of life for amputees.

Spinal Cord Stimulation Combined with Anterior Cingulotomy to Manage Refractory Phantom Limb Pain.

BACKGROUND: Phantom limb pain (PLP) is an intractable and debilitating disease without satisfactory treatment options presently available. Central reorganization, peripheral changes, and psychiatric factors contribute to its development; thus, a neuropsychiatry-orientated combined therapy could be promising. OBJECTIVES: We used a combined strategy with the aims of demonstrating its therapeutic outcomes on PLP. METHODS: The patient initially received spinal cord stimulation (SCS) implantation and then anterior cingulotomy (ACING) 2 years later. We administered the Hamilton Depression Scale-24, Hamilton Anxiety Scale, Pain Rating Index, Numerical Pain Rating Scale, and the Short Form (36) Health Survey to assess its outcomes at 5 time points, namely the time before performing SCS implantation, 1 year and 2 years after SCS implantation, and 1 year and 2 years after SCS combined with ACING. RESULTS: Excellent pain relief and significant improvement in depression symptoms were observed in this patient with PLP who underwent SCS combined with ACING. CONCLUSIONS: This report suggests that SCS combined with ACING is efficacious for PLP. However, further studies are warranted.

Percutaneous Image-Guided Cryoablation for the Treatment of Phantom Limb Pain in Amputees: A Pilot Study.

PURPOSE: To prospectively evaluate percutaneous image-guided nerve cryoablation for treatment of refractory phantom limb pain (PLP) in a pilot cohort for purposes of deriving parameters to design a larger, randomized, parallel-armed, controlled trial. MATERIALS AND METHODS: From January 2015 to January 2016, 21 patients with refractory PLP underwent image-guided percutaneous cryoneurolysis procedures. Visual analog scale scores were documented at baseline and 7, 45, and 180 days after the procedure. Responses to a modified Roland Morris Disability Questionnaire were documented at baseline and 7 and 45 days after the procedure. RESULTS: Technical success rate of the procedures was 100%. There were 6 (29%) minor procedure-related complications. Disability scores decreased from a baseline mean of 11.3 to 3.3 at 45-day follow-up (95% confidence interval 5.8, 10.3; P < .0001). Pain intensity scores decreased from a baseline mean of 6.2 to 2.0 at long-term follow-up (95% confidence interval 2.8, 5.6; P < .0001). CONCLUSIONS: Image-guided percutaneous nerve cryoablation is feasible and safe and may represent a new efficacious therapeutic option for patients with phantom pains related to limb loss.

Coblation of Femoral and Sciatic Nerve for Stump Pain and Phantom Limb Pain: A Case Report.

BACKGROUND: There is currently no reliable treatment for stump pain and phantom limb pain. Peripheral factors play a significant role in the pathophysiology of stump pain and phantom limb pain. Coblation technology is a relatively new technology that has shown promise in treating neuropathic pain. CASE REPORT: This report describes the use of coblation technology on femoral and sciatic nerve for stump pain and phantom limb pain. An ultrasound-guided perineural infiltration anesthesia surrounding the neuroma was first performed and achieved approximately 60% stump pain relief that lasted for 2 hours, but no relief of the phantom limb pain. An ultrasound-guided femoral and sciatic nerve block was performed to obtain longer pain relief. The patient reported approximately 80% pain relief in both stump pain and phantom limb pain that lasted for 40 hours. This finding suggested other factors in addition to the ultrasound-detected neuroma in the residual limb generating pain for this patient. Coblation of femoral and sciatic nerves was performed. The stump pain was completely relieved immediately after operation. At 1, 3, and 6 months postoperative review, 80% relief of both stump and phantom limb pain was achieved. Overall activity was improved and there was no need for pain medications. The analgesic effect was stable during the 6-month follow-up period. CONCLUSION: Our report suggests that coblation technology may be useful treatment for stump pain and phantom limb pain. Treatments focusing on peripheral nerves may be more effective than those focusing on the neuroma. This finding needs additional study for confirmation.

[Lumbar sympathectomy literature review over the past 15 years]. / Lumbálna sympatektómia prehlad svetovej literatúry za posledných 15 rokov.

INTRODUCTION: Lumbar sympathectomy (LS) irreversibly damages a part of the sympathetic trunk and adjacent ganglia between L1 and L5, typically between L2 and L4. The first LS was performed in 1923. Initially, it used to be performed very often; however, with the progress of vascular and endovascular surgery its importance gradually continues to decline. The aim of the paper is to present literature review focusing on LS over the past 15 years. METHOD: Literature review of 113 academic articles found in academic journal databases. PATHOPHYSIOLOGY: Irreversible interruption of the efferent innervation leads to relative vasodilation of small vessels in lower extremities (α1-receptors blockade), and it reduces the volume of sweat due to inactivation of eccrine glands and nociception from lower limbs. INDICATION: Raynaud´s phenomenon, thromboangitis obliterans, non-revascularizable peripheral arterial disease (PAD) (Fontain grade III-IV), hyperhidrosis, persistent pain in lower extremities, chronic pain of amputation stump, frostbites, chilblains.Effect: The three largest studies showed a positive effect in 63.6-93.4% cases of PAD and in 97%100% cases of hyperhidrosis. The positive effect was defined as warmer lower extremities, increased blood flow, acceleration of chronic defects healing, sweating disappearance and pain reduction. CONCLUSION: Lumbar sympathectomy still remains a useful method in the treatment of above mentioned diseases if properly indicated. KEY WORDS: lumbar sympathectomy - Raynaud´s phenomenon - thromboangitis obliterans -peripheral arterial disease - hyperhidrosis.

Phantom Remodeling Effect of Dorsal Root Entry Zone Lesioning in Phantom Limb Pain Caused by Brachial Plexus Avulsion.

BACKGROUND: Dorsal root entry zone (DREZ) lesioning has been reported to be effective for phantom limb pain caused by brachial plexus avulsion pain. Most reports on DREZ lesioning for brachial plexus avulsion pain have focused on the results of pain relief without a detailed description of phantom sensations following DREZ lesioning. MATERIALS AND METHODS: Two patients (1 with amputation and the other nonamputated) with chronic intractable phantom limb pain caused by brachial plexus avulsion underwent DREZ lesioning on the avulsed segments of the cervical spinal cords. Changes of the phantom limb were observed. RESULTS: Immediately following DREZ lesioning, the phantom limb pain disappeared in the amputee, the phantom arm was shortened and the phantom hand disappeared. The other patient with the nonamputated arm reported an immediate 50% reduction in the size of the phantom hand, and pain relief was up to 70% of the preoperative phantom limb pain. There was no further change in the phantom arm and hand during the follow-up of 1.5-2 years. CONCLUSIONS: The phantom arms and hands showed a prompt shortening and reduction in size, rather than a disappearance, following successful DREZ lesioning in patients with chronic phantom limb pain caused by brachial plexus avulsion.

Pain Management in Four-Limb Amputation: A Case Report.

Acute pain following amputation can be challenging to treat due to multiple underlying mechanisms and variable clinical responses to treatment. Furthermore, poorly controlled preoperative pain is a risk factor for developing chronic pain. Evidence suggests that epidural analgesia and peripheral nerve blockade may decrease the severity of residual limb pain and the prevalence of phantom pain after lower extremity amputation. We present the perioperative analgesic management of a patient with gangrene of the bilateral upper and lower extremities as a result of septic shock and prolonged vasopressor administration who underwent four-limb amputation in a single procedure. A multimodal analgesic regimen was utilized, including titration of preoperative opioid and neuropathic pain agents, perioperative intravenous, epidural and peripheral nerve catheter infusions, and postoperative oral medication titration. More than 8 months postoperatively, the patient has satisfactory pain control with no evidence for phantom limb pain. To our knowledge, there have been no publications to date concerning analgesic regimens in four-limb amputation.

Treatment of phantom limb pain by cryoneurolysis of the amputated nerve.

The pathophysiology of phantom limb pain (PLP) is multifactorial. It probably starts in the periphery and is amplified and modified in the central nervous system. A small group of patients with PLP were questioned as to the portion of the phantom limb affected by pain (e.g., "great toe," "thumb"). In the stump, the corresponding amputated nerve was located with a nerve stimulator. With correct placement and stimulation, the PLP could then be reproduced or exacerbated. A small dose of local anesthesia was then injected, resulting in the disappearance of the PLP. If a peripheral nerve injection gave temporary relief, our final treatment was cryoanalgesia at this location. Evaluation of 5 patients, followed for at least 2.5 years, yielded the following results: 3 patients had excellent results (100%, 95%, and 90% decrease in complaints, respectively), 1 patient had an acceptable result (40% decrease), and 1 patient had only a 20% decrease in pain. Although both central and peripheral components are likely involved in PLP, treatment of a peripheral pain locus with cryoanalgesia should be considered. We propose the identification of a peripheral etiology may help match patients to an appropriate therapy, and cryoanalgesia may result in long-term relief of PLP.

Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to "target" motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR's effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.

[Bionic Surgery Meets Bionic Reconstruction - First In-human use of Robotic Microsurgery in Targeted Muscle Reinnervation]. / Bionische Chirurgie trifft Bionische Rekonstruktion ­ erstes in-human Projekt von robotischer Mikrochirurgie zur Targeted Muscle Reinnervation.

Robotic microsurgery is an emerging field in reconstructive surgery, which provides benefits such as improved precision, optimal ergonomics, and reduced tremors. However, only a few robotic platforms are available for performing microsurgical procedures, and successful nerve coaptation is still a challenge. Targeted muscle reinnervation (TMR) is an innovative reconstructive procedure that rewires multiple nerves to remnant stump muscles, thereby reducing neuroma and phantom limb pain and improving the control of bionic prostheses. The precision of surgical techniques is critical in reducing axonal sprouting around the coaptation site to minimise the potential for neuroma formation. This study reports the first use of a microsurgical robotic platform for multiple nerve transfers in a patient undergoing TMR for bionic extremity reconstruction. The Symani robotic platform, combined with external microscope magnification, was successfully used, and precise handling of nerve tissue and coaptation was easily feasible even in anatomically challenging environments. While the precision and stability offered by robotic assistance may be especially useful for nerve surgery, the high economic costs of robotic microsurgery remain a major challenge for current healthcare systems. In conclusion, this study demonstrated the feasibility of using a robotic microsurgical platform for nerve surgery and transfers, where precise handling of tissue is crucial and limited space is available. Future studies will explore the full potential of robotic microsurgery in the future.

Targeted Muscle Reinnervation at the Time of Amputation Decreases Recurrent Symptomatic Neuroma Formation.

BACKGROUND: Targeted muscle reinnervation (TMR) is an effective technique for the prevention and management of phantom limb pain (PLP) and residual limb pain (RLP) among amputees. The purpose of this study was to evaluate symptomatic neuroma recurrence and neuropathic pain outcomes between cohorts undergoing TMR at the time of amputation (ie, acute) versus TMR following symptomatic neuroma formation (ie, delayed). METHODS: A cross-sectional, retrospective chart review was conducted using patients undergoing TMR between 2015 and 2020. Symptomatic neuroma recurrence and surgical complications were collected. A subanalysis was conducted for patients who completed Patient-Reported Outcome Measurement Information System (PROMIS) pain intensity, interference, and behavior scales and an 11-point numeric rating scale (NRS) form. RESULTS: A total of 105 limbs from 103 patients were identified, with 73 acute TMR limbs and 32 delayed TMR limbs. Nineteen percent of the delayed TMR group had symptomatic neuromas recur in the distribution of original TMR compared with 1% of the acute TMR group ( P < 0.05). Pain surveys were completed at final follow-up by 85% of patients in the acute TMR group and 69% of patients in the delayed TMR group. Of this subanalysis, acute TMR patients reported significantly lower PLP PROMIS pain interference ( P < 0.05), RLP PROMIS pain intensity ( P < 0.05), and RLP PROMIS pain interference ( P < 0.05) scores in comparison to the delayed group. CONCLUSIONS: Patients who underwent acute TMR reported improved pain scores and a decreased rate of neuroma formation compared with TMR performed in a delayed fashion. These results highlight the promising role of TMR in the prevention of neuropathic pain and neuroma formation at the time of amputation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Surgical treatments for postamputation pain: study protocol for an international, double-blind, randomised controlled trial.

BACKGROUND: Painful conditions such as residual limb pain (RLP) and phantom limb pain (PLP) can manifest after amputation. The mechanisms underlying such postamputation pains are diverse and should be addressed accordingly. Different surgical treatment methods have shown potential for alleviating RLP due to neuroma formation - commonly known as neuroma pain - and to a lesser degree PLP. Two reconstructive surgical interventions, namely targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI), are gaining popularity in postamputation pain treatment with promising results. However, these two methods have not been directly compared in a randomised controlled trial (RCT). Here, we present a study protocol for an international, double-blind, RCT to assess the effectiveness of TMR, RPNI, and a non-reconstructive procedure called neuroma transposition (active control) in alleviating RLP, neuroma pain, and PLP. METHODS: One hundred ten upper and lower limb amputees suffering from RLP will be recruited and assigned randomly to one of the surgical interventions (TMR, RPNI, or neuroma transposition) in an equal allocation ratio. Complete evaluations will be performed during a baseline period prior to the surgical intervention, and follow-ups will be conducted in short term (1, 3, 6, and 12 months post-surgery) and in long term (2 and 4 years post-surgery). After the 12-month follow-up, the study will be unblinded for the evaluator and the participants. If the participant is unsatisfied with the outcome of the treatment at that time, further treatment including one of the other procedures will be discussed in consultation with the clinical investigator at that site. DISCUSSION: A double-blind RCT is necessary for the establishment of evidence-based procedures, hence the motivation for this work. In addition, studies on pain are challenging due to the subjectivity of the experience and the lack of objective evaluation methods. Here, we mitigate this problem by including different pain evaluation methods known to have clinical relevance. We plan to analyse the primary variable, mean change in NRS (0-10) between baseline and the 12-month follow-up, using the intention-to-treat (ITT) approach to minimise bias and keep the advantage of randomisation. The secondary outcomes will be analysed on both ITT and per-protocol (PP). An adherence protocol (PP population) analysis will be used for estimating a more realistic effect of treatment. TRIAL REGISTRATION: ClincialTrials.gov NCT05009394.