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JBJS Essential Surgical Techniques 2024A neuroma occurs when a regenerating transected peripheral nerve has no distal target to reinnervate. Symptomatic neuromas are a common cause of postamputation pain that...
BACKGROUND
A neuroma occurs when a regenerating transected peripheral nerve has no distal target to reinnervate. Symptomatic neuromas are a common cause of postamputation pain that can lead to substantial disability. Regenerative peripheral nerve interface (RPNI) surgery may benefit patients through the use of free nonvascularized muscle grafts as physiologic targets for peripheral nerve reinnervation for mitigation of neuroma and postamputation pain.
DESCRIPTION
An RPNI is constructed by implanting the distal end of a transected peripheral nerve into a free nonvascularized skeletal muscle graft. The neuroma or free end of the affected nerve is identified, transected, and skeletonized. A free muscle graft is then harvested from the donor thigh or from the existing amputation site, and the distal end of each transected nerve is implanted into the center of the free muscle graft with use of 6-0 nonabsorbable suture. This can be done acutely at the time of amputation or as an elective procedure at any time postoperatively.
ALTERNATIVES
Nonsurgical treatments of neuromas include desensitization, chemical or anesthetic injections, biofeedback, transcutaneous electrical nerve stimulation, topical lidocaine, and/or other medications (e.g., antidepressants, anticonvulsants, and opioids). Surgical treatment of neuromas includes neuroma excision, nerve capping, excision with transposition into bone or muscle, nerve grafting, and targeted muscle reinnervation.
RATIONALE
Creation of an RPNI is a simple and reproducible surgical option to prevent neuroma formation that leverages several biologic processes and addresses many limitations of existing neuroma-treatment strategies. Given the understanding that neuromas will form when regenerating axons are not presented with end organs for reinnervation, any strategy that reduces the number of aimless axons within a residual limb should serve to reduce symptomatic neuromas. The use of free muscle grafts offers a vast supply of denervated muscle targets for regenerating nerve axons and facilitates the reestablishment of neuromuscular junctions without sacrificing denervation of any residual muscles.
EXPECTED OUTCOMES
Articles describing RPNI surgery for postamputation pain have shown favorable outcomes, with significant reduction in neuroma pain and phantom pain scores at approximately 7 months postoperatively. Neuroma pain scores were reduced by 71% and phantom pain scores were reduced by 53%. Prophylactic RPNI surgery is also associated with substantially lower incidence of symptomatic neuromas (0% versus 13.3%) and a lower rate of phantom limb pain (51.1% versus 91.1%) compared with the rates in patients who did not undergo RPNI surgery.
IMPORTANT TIPS
Ask the patient preoperatively to point at the site of maximal tenderness, as this can serve as a guide for where the symptomatic neuroma may be located. The incision can be made either through the previous site of the amputation or directly over the site of maximal tenderness longitudinally. The pitfall of incising directly over the site is creating another incision with its attendant risk of wound infection.Excise the terminal neuroma with a knife until healthy-appearing axons are visualized.The free nonvascularized skeletal muscle graft can be obtained from local muscle (preferred) or from a separate donor site. A separate donor site can introduce donor-site morbidity and complications, including hematoma and pain.The harvested skeletal muscle graft should ideally be approximately 35 mm long, 20 mm wide, and 5 mm thick in order to ensure survivability and to prevent central necrosis. The harvesting can be performed with curved Mayo scissors.The peripheral nerve should be implanted parallel to the direction of the muscle fibers, and the epineurium should be secured to the free muscle graft at 1 or 2 places. One suture should be utilized to tack the distal end of the epineurium to the middle of the bed of the muscle graft. Another suture should be utilized to start the wrapping of the muscle graft around the nerve using a bite through the muscle, a bite through the epineurium of the proximal end of the nerve, and another bite through the other muscle edge in order to form a cylindrical wrap around the nerve.Wrap the entire muscle graft by taking only bites of muscle graft around the nerve to secure the muscle graft in a cylindrical structure using 2 to 4 more sutures.Avoid locating the RPNI near weight-bearing surfaces of the residual limb when closing. The RPNI should be in the muscular tissue, deep to the subcutaneous tissue and dermis.Do perform intraneural dissection for large-caliber nerves to create several (normally 2 to 4) distinct RPNIs, to avoid too many regenerating axons in a single free muscle graft.
PubMed: 38348364
DOI: 10.2106/JBJS.ST.23.00009 -
Foot & Ankle Specialist Feb 2024The incidence of phantom limb pain in patients with Charcot neuroarthropathy who undergo major amputation is not well described. The purpose of this study was to...
BACKGROUND
The incidence of phantom limb pain in patients with Charcot neuroarthropathy who undergo major amputation is not well described. The purpose of this study was to determine whether patients with Charcot neuroarthropathy and diabetes who underwent either a below-knee amputation (BKA) or above-knee amputation (AKA) had an increased rate of phantom limb pain compared with those with a diagnosis of diabetes alone.
METHODS
Using international classification of disease (ICD) and common procedural terminology (CPT) codes, the TriNetX research database identified 10 239 patients who underwent BKA and 6122 who underwent AKA between 2012 and 2022. Diabetic patients with and without Charcot neuroarthropathy were compared in terms of demographics and relative risk of developing phantom limb pain after AKA or BKA.
RESULTS
Age, sex, ethnicity, and race did not significantly differ between groups. Charcot neuroarthropathy was associated with significantly increased risk of phantom limb pain following both BKA (risk ratio [RR]: 1.2, 95% confidence interval [CI]: 1.1-1.3, P < .01) and AKA (RR: 1.6, 95% CI: 1.2-2.3, P < .0068).
CONCLUSION
Our results indicate that patients with a coexisting diagnosis of Charcot neuroarthropathy who require BKA or AKA may have an increased risk of developing phantom limb pain.
LEVELS OF EVIDENCE
Level III.
PubMed: 38344975
DOI: 10.1177/19386400241230597 -
BMC Neurology Feb 2024We previously performed a systematic review and meta-analysis which revealed a Phantom Limb Pain (PLP) prevalence estimate of 64% [95% CI: 60.01-68.1]. The prevalence... (Meta-Analysis)
Meta-Analysis
BACKGROUND
We previously performed a systematic review and meta-analysis which revealed a Phantom Limb Pain (PLP) prevalence estimate of 64% [95% CI: 60.01-68.1]. The prevalence estimates varied significantly between developed and developing countries. Remarkably, there is limited evidence on the prevalence of PLP and associated risk factors in African populations.
METHODS
Adults who had undergone limb amputations between January 2018 and October 2022 were recruited from healthcare facilities in the Western and Eastern Cape Provinces. We excluded individuals with auditory or speech impairments that hindered clear communication via telephone. Data on the prevalence and risk factors for PLP were collected telephonically from consenting and eligible participants. The prevalence of PLP was expressed as a percentage with a 95% confidence interval. The associations between PLP and risk factors for PLP were tested using univariate and multivariable logistic regression analyses. The strength of association was calculated using the Odds Ratio where association was confirmed.
RESULTS
The overall PLP prevalence was 71.73% [95% CI: 65.45-77.46]. Persistent pre-operative pain, residual limb pain, and non-painful phantom limb sensations were identified as risk factors for PLP.
CONCLUSION
This study revealed a high prevalence of PLP. The use of effective treatments targeting pre-amputation pain may yield more effective and targeted pre-amputation care, leading to improved quality of life after amputation.
Topics: Humans; Cross-Sectional Studies; Phantom Limb; Prevalence; Quality of Life; Risk Factors
PubMed: 38321380
DOI: 10.1186/s12883-024-03547-w -
Arquivos de Neuro-psiquiatria Jan 2024Phantom limb pain (PLP) occurs after amputations and can persist in a chronic and debilitating way. Repetitive transcranial magnetic stimulation (rTMS) is a...
BACKGROUND
Phantom limb pain (PLP) occurs after amputations and can persist in a chronic and debilitating way. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation method capable of influencing brain function and modulating cortical excitability. Its effectiveness in treating chronic pain is promising.
OBJECTIVE
To evaluate the evidence on the efficacy and safety of using rTMS in the treatment of PLP, observing the stimulation parameters used, side effects, and benefits of the therapy.
METHODS
This is a systematic review of scientific articles published in national and international literature using electronic platforms.
RESULTS
Two hundred and fifty two articles were identified. Two hundred and forty six publications were removed because they were duplicated or met the exclusion criteria. After selection, six studies were reviewed, those being two randomized clinical trials and four case reports. All evaluated studies indicated some degree of benefit of rTMS to relieve painful symptoms, even temporarily. Pain perception was lower at the end of treatment when compared to the period prior to the sessions and remained during patient follow-up. There was no standardization of the stimulation parameters used. There were no reports of serious adverse events. The effects of long-term therapy have not been evaluated.
CONCLUSION
There are some benefits, even if temporary, in the use of rTMS to relieve painful symptoms in PLP. High-frequency stimulation at M1 demonstrated a significant analgesic effect. Given the potential that has been demonstrated, but limited by the paucity of high-quality studies, further controlled studies are needed to establish and standardize the clinical use of the method.
Topics: Humans; Transcranial Magnetic Stimulation; Phantom Limb; Chronic Pain
PubMed: 38286434
DOI: 10.1055/s-0044-1779051 -
JBJS Essential Surgical Techniques 2023The agonist-antagonist myoneural interface (AMI) technique at the time of transtibial amputation involves the use of agonist-antagonist muscle pairs to restore natural...
BACKGROUND
The agonist-antagonist myoneural interface (AMI) technique at the time of transtibial amputation involves the use of agonist-antagonist muscle pairs to restore natural contraction-stretch relationships and to improve proprioceptive feedback when utilizing a prosthetic limb.
DESCRIPTION
Utilizing the standard incision for a long posterior myofasciocutaneous flap, the lateral and medial aspects of the limb are dissected, identifying and preserving the superficial peroneal and saphenous nerve, respectively. The tendons of the tibialis anterior and peroneus longus are transected distally to allow adequate length for the AMI constructs. After ligation of the anterior tibial vessels, the deep peroneal nerve is identified and tagged to create a regenerative peripheral nerve interface (RPNI). The tibia and fibula are cut approximately 15 cm from the medial joint line, facilitating dissection of the deep posterior compartment and ligation of the peroneal and posterior tibial vessels. The tendons of the lateral gastrocnemius and tibialis posterior are transected distally, and the amputation is completed. The extensor retinaculum is harvested from the residual limb along with multiple 2 × 3-cm free muscle grafts, which will be used for the RPNI constructs. The retinaculum is secured to the tibia with suture anchors, and AMI pairs of the lateral gastrocnemius and tibialis anterior as well as the tibialis posterior and peroneus longus are constructed. Separate RPNIs of the major lower-extremity nerves are performed, and the wound is closed in a standard layered fashion.
ALTERNATIVES
An isometric myodesis of the gastrocnemius without coaptation of agonist-antagonist muscle pairs can be performed at the time of transtibial amputation.
RATIONALE
The AMI technique restores natural agonist-antagonist relationships at the time of transtibial amputation to increase proprioceptive feedback and improve prosthetic control. These outcomes contrast with those of a traditional isometric myodesis, which prevents proprioceptive communication from the residual limb musculature to the central nervous system. Additionally, the AMI technique allows for concentric and eccentric muscular contractions, which may contribute to the maintenance of limb volume and aid with prosthetic fitting, as opposed to the typical limb atrophy observed following standard transtibial amputation. With the development and availability of more advanced prostheses, the AMI technique offers more precise control and increases the functionality of these innovative devices.
EXPECTED OUTCOMES
Early clinical outcomes of the AMI technique at the time of transtibial amputation have been promising. In a case series of the first 3 patients who underwent the procedure, complications were minor and consisted of 2 episodes of cellulitis and 1 case of delayed wound healing. Muscle activation measured through electromyography demonstrated an improved ability to limit unintended muscular co-contraction with attempted movement of the phantom limb, as compared with patients who underwent a standard transtibial amputation. Additionally, residual limb volume was maintained postoperatively without the need for substantial prosthetic modifications.
IMPORTANT TIPS
The tendons of the tibialis anterior, peroneus longus, tibialis posterior, and lateral gastrocnemius should be transected as distal as possible to allow adequate length for creation of the AMI constructs.Approximately 2 × 3-cm free muscle grafts are harvested from the amputated extremity for RPNI.Smooth tendon-gliding through the synovial tunnels should be confirmed before closure. If necessary, muscle debulking can improve gliding and decrease the size of the residual limb.Harvesting the extensor retinaculum for synovial tunnels has been our preferred method, although we acknowledge that other grafts options such as the tarsal tunnel are available.
ACRONYMS & ABBREVIATIONS
RPNI = regenerative peripheral nerve interfaceAMI = agonist-antagonist myoneural interfaceEMG = electromyographic.
PubMed: 38282725
DOI: 10.2106/JBJS.ST.22.00038 -
Wounds : a Compendium of Clinical... Dec 2023Each year, 27.5% of the 150 000 people in the United States who require lower extremity amputation experience significant postoperative complications, including pain,... (Review)
Review
Each year, 27.5% of the 150 000 people in the United States who require lower extremity amputation experience significant postoperative complications, including pain, infection, and need for reoperation. Postamputation pain, including RLP and PLP, is debilitating. While the causes of such pain remain unknown, neuroma formation following sensory nerve transection is believed to be a major contributor. Various techniques exist for management of a symptomatic neuroma, but few data exist on which technique is superior. Furthermore, there are few data on primary prevention of neuroma formation following injury or intentional transection. The TMR technique shows promise for both management of PLP and RLP and prevention of neuroma formation. Following amputation, transected sensory nerves are coapted to nearby motor nerve supplying remaining extremity musculature. Not only does this procedure generate increased myoelectric signals for improved prosthesis control, TMR appears to neurophysiologically alter sensory nerves, preventing formation of painful sensory neuromas. The sole RCT to date evaluating the efficacy of TMR showed statistically significant reduction in PLP. TMR is not limited to use in the setting of major limb amputation. It has also been used in the setting of post-mastectomy pain, abdominal wall neuromas, digital amputations, and headache surgeries. This article reviews the origin of TMR and provides a brief description of histologic changes following the procedure, as well as current data regarding the efficacy of TMR with regard to postoperative pain relief. It also seeks to provide a concise, comprehensive resource for providers to facilitate better discussions with patients about treatment options.
Topics: Humans; Female; Phantom Limb; Breast Neoplasms; Nerve Transfer; Muscle, Skeletal; Mastectomy; Amputation, Surgical; Neuroma
PubMed: 38277632
DOI: 10.25270/wnds/23079 -
Neurologia Medico-chirurgica Mar 2024Phantom limb pain is attributed to abnormal sensorimotor cortical representations. Various feedback treatments have been applied to induce the reorganization of the... (Review)
Review
Phantom limb pain is attributed to abnormal sensorimotor cortical representations. Various feedback treatments have been applied to induce the reorganization of the sensorimotor cortical representations to reduce pain. We developed a training protocol using a brain-computer interface (BCI) to induce plastic changes in the sensorimotor cortical representation of phantom hand movements and demonstrated that BCI training effectively reduces phantom limb pain. By comparing the induced cortical representation and pain, the mechanisms worsening the pain have been attributed to the residual phantom hand representation. Based on our data obtained using neurofeedback training without explicit phantom hand movements and hand-like visual feedback, we suggest a direct relationship between cortical representation and pain. In this review, we summarize the results of our BCI training protocol and discuss the relationship between cortical representation and phantom limb pain. We propose a treatment for phantom limb pain based on real-time neuroimaging to induce appropriate cortical reorganization by monitoring cortical activities.
Topics: Humans; Phantom Limb; Motor Cortex; Sensorimotor Cortex; Hand; Neuroimaging
PubMed: 38267056
DOI: 10.2176/jns-nmc.2023-0206 -
Medicina (Kaunas, Lithuania) Dec 2023Phantom limb pain (PLP) is a challenging condition affecting a significant proportion of amputees. In this article, we describe the case of a 54-year-old Paralympic...
Phantom limb pain (PLP) is a challenging condition affecting a significant proportion of amputees. In this article, we describe the case of a 54-year-old Paralympic athlete with phantom limb syndrome following right leg amputation and widespread sports-related enthesitic pain who underwent a whole-body cryostimulation (WBC) cycle, an emerging treatment known for its rapid pain-relieving and anti-inflammatory effects. Assessments were conducted before and after a 10-session WBC cycle, including pain and quality of life assessment and use of medications. A substantial reduction in enthesitic pain, PLP intensity, paresthesia, and tingling related to atmospheric events and improved function and quality of life were reported after the WBC cycle and lasted for two weeks. One month after WBC, the enthesitic pain following sports activity and PLP gradually returned, but with lesser intensity. Similarly, the stump's sensitivity to atmospheric changes returned, but with lower frequency. Pain at night remained lower than before WBC, with significantly improved quality of sleep. This case study suggests that WBC could be a valuable adjuvant treatment for alleviating PLP. Controlled studies are warranted to validate the findings of this case report and elucidate the mechanisms underlying the positive effects of WBC in this condition.
Topics: Humans; Middle Aged; Phantom Limb; Quality of Life; Amputation, Surgical; Adjuvants, Immunologic; Leg
PubMed: 38256283
DOI: 10.3390/medicina60010022 -
Journal of Neuroengineering and... Jan 2024Tremors are involuntary rhythmic movements commonly present in neurological diseases such as Parkinson's disease, essential tremor, and multiple sclerosis. Intention... (Review)
Review
BACKGROUND
Tremors are involuntary rhythmic movements commonly present in neurological diseases such as Parkinson's disease, essential tremor, and multiple sclerosis. Intention tremor is a subtype associated with lesions in the cerebellum and its connected pathways, and it is a common symptom in diseases associated with cerebellar pathology. While clinicians traditionally use tests to identify tremor type and severity, recent advancements in wearable technology have provided quantifiable ways to measure movement and tremor using motion capture systems, app-based tasks and tools, and physiology-based measurements. However, quantifying intention tremor remains challenging due to its changing nature.
METHODOLOGY & RESULTS
This review examines the current state of upper limb tremor assessment technology and discusses potential directions to further develop new and existing algorithms and sensors to better quantify tremor, specifically intention tremor. A comprehensive search using PubMed and Scopus was performed using keywords related to technologies for tremor assessment. Afterward, screened results were filtered for relevance and eligibility and further classified into technology type. A total of 243 publications were selected for this review and classified according to their type: body function level: movement-based, activity level: task and tool-based, and physiology-based. Furthermore, each publication's methods, purpose, and technology are summarized in the appendix table.
CONCLUSIONS
Our survey suggests a need for more targeted tasks to evaluate intention tremors, including digitized tasks related to intentional movements, neurological and physiological measurements targeting the cerebellum and its pathways, and signal processing techniques that differentiate voluntary from involuntary movement in motion capture systems.
Topics: Humans; Essential Tremor; Movement; Parkinson Disease; Tremor; Upper Extremity; Wearable Electronic Devices
PubMed: 38218890
DOI: 10.1186/s12984-023-01302-9 -
BioRxiv : the Preprint Server For... Dec 2023Neuroscientists have long debated the adult brain's capacity to reorganize itself in response to injury. A driving model for studying plasticity has been limb...
Neuroscientists have long debated the adult brain's capacity to reorganize itself in response to injury. A driving model for studying plasticity has been limb amputation. For decades, it was believed that amputation triggers large-scale reorganization of cortical body resources. However, these studies have relied on cross-sectional observations post-amputation, without directly tracking neural changes. Here, we longitudinally followed adult patients with planned arm amputations and measured hand and face representations, before and after amputation. By interrogating the representational structure elicited from movements of the hand (pre-amputation) and phantom hand (post-amputation), we demonstrate that hand representation is unaltered. Further, we observed no evidence for lower face (lip) reorganization into the deprived hand region. Collectively, our findings provide direct and decisive evidence that amputation does not trigger large-scale cortical reorganization.
PubMed: 38168448
DOI: 10.1101/2023.12.13.571314