Insufficient pain relief after surgical neuroma treatment: Prognostic factors and central sensitisation

Multidisciplinary strategies to treat painful mononeuropathies in the upper extremity: from lab to bedside

Neuropathic pain in the upper extremity is a serious problem, commonly involving relatively young patients. The pain causes loss of function and productivity, changes a patient's lifestyle and can progress into a chronic pain syndrome with secondary psychosocial co-morbidities. Treating patients with a painful mononeuropathy remains challenging, with a monodisciplinary approach often having limited treatment efficacy. This narrative review discusses how to deal with this challenge in the treatment of patients with peripheral nerve injury pain, addressing the four important pillars: (1) diagnosing a painful mononeuropathy; (2) clinical pain phenotyping; (3) personalized pain treatment; and (4) using a multidisciplinary team approach.

Superficial branch of the radial nerve regularly contains fibers from the lateral antebrachial cutaneous nerve: A role in neuroma treatment

BACKGROUND

Many surgical strategies aim to treat the symptomatic neuroma of the superficial branch of the radial nerve (SBRN). It is still difficult to treat despite many attempts to reveal a reason for surgical treatment failure. The lateral antebrachial cutaneous nerve (LACN) is known to overlap and communicate with SBRN. Our study aims to determine the frequency of spreading of LACN fibers into SBRN branches through a microscopic dissection to predict where and how often LACN fibers may be involved in SBRN neuroma.

METHODS

Eighty-seven cadaveric forearms were thoroughly dissected. The path of LACN fibers through the SBRN branching was ascertained using microscopic dissection. Distances between the interstyloid line and entry of LACN fibers into the SBRN and emerging and bifurcation points of the SBRN were measured.

RESULTS

The LACN fibers joined the SBRN at a mean distance of 1.7 ± 2.5 cm proximal to the interstyloid line. The SBRN contained fibers from the LACN in 62% of cases. Most commonly, there were LACN fibers within the SBRN's third branch (59%), but they were also observed within the first branch, the second branch, and their common trunk (21%, 9.2%, and 22%, respectively). The lowest rate of the LACN fibers was found within the SBRN trunk (6.9%).

CONCLUSION

The SBRN contains LACN fibers in almost 2/3 of the cases, therefore, the denervation of both nerves might be required to treat the neuroma. However, the method must be considered based on the particular clinical situation.

Biology and pathophysiology of symptomatic neuromas

ABSTRACT

Neuromas are a substantial cause of morbidity and reduction in quality of life. This is not only caused by a disruption in motor and sensory function from the underlying nerve injury but also by the debilitating effects of neuropathic pain resulting from symptomatic neuromas. A wide range of surgical and therapeutic modalities have been introduced to mitigate this pain. Nevertheless, no single treatment option has been successful in completely resolving the associated constellation of symptoms. While certain novel surgical techniques have shown promising results in reducing neuroma-derived and phantom limb pain, their effectiveness and the exact mechanism behind their pain-relieving capacities have not yet been defined. Furthermore, surgery has inherent risks, may not be suitable for many patients, and may yet still fail to relieve pain. Therefore, there remains a great clinical need for additional therapeutic modalities to further improve treatment for patients with devastating injuries that lead to symptomatic neuromas. However, the molecular mechanisms and genetic contributions behind the regulatory programs that drive neuroma formation-as well as the resulting neuropathic pain-remain incompletely understood. Here, we review the histopathological features of symptomatic neuromas, our current understanding of the mechanisms that favor neuroma formation, and the putative contributory signals and regulatory programs that facilitate somatic pain, including neurotrophic factors, neuroinflammatory peptides, cytokines, along with transient receptor potential, and ionotropic channels that suggest possible approaches and innovations to identify novel clinical therapeutics.

Neuropathic pain of the superficial branch of the radial nerve - Factors influencing surgical outcome and patient satisfaction

BACKGROUND

Due to its partially superficial course, the superficial branch of the radial nerve is vulnerable to injury by trauma or surgery, potentially leading to painful neuroma. Surgical treatment is difficult. Among other factors, smoking and duration of pain before revision surgery have been suggested as risk factors for persistent pain after surgical revision, without concrete evidence. The aim of this study was therefore to identify factors influencing the outcome of revision surgery in SBRN neuropathic pain in our department.

METHODS

All 51 patients receiving revision surgery of the superficial branch of the radial nerve for neuropathic pain from 2010 to 2020 were contacted; 19 agreed to return for assessment. A medical chart review was performed to collect patient-, pain- and treatment-specific factors. Outcomes were recorded. In an outpatient consultation, clinical follow-up was performed and patients filled out the DASH, MHQ and painDETECT questionnaires.

RESULTS

After revision surgery, all patients experienced persistent pain. On multivariate logistic regression evaluating the risk of persistent pain, only smoking emerged as an independent risk factor. Age, gender, dominant side, location, time between trigger and surgery or diagnosis did not emerge as risk factors. No predictor for successful return to work could be identified.

CONCLUSIONS

Treatment of painful neuroma of the superficial branch of the radial nerve is a challenge. Patients with neuropathic pain should be coached toward smoking cessation before neuroma surgery. Surgery can show benefit even after long symptom duration. No correlations between study clinical variables or test results and return to work could be identified, suggesting that other factors play a role in return to work.

Patient-reported outcomes after free muscle flap coverage for therapy-resistant neuropathic pain from the ulnar nerve

Extensive microsurgical neurolysis followed by free gracilis muscle flap coverage can be performed as a last resort for patients with persistent neuropathic pain of the ulnar nerve. All patients who had this surgery between 2015 and 2021 were identified. Data were collected from the medical records of 21 patients and patient-reported outcomes were collected from 18 patients, with a minimum follow-up of 12 months. The median visual analogue pain score decreased significantly 8 months postoperatively from 8.0 to 6.0 and stabilized to 5.4 at the 3-year follow-up. Health-related quality-of-life scores remained diminished compared to normative data. In the treatment of therapy-resistant neuropathic pain of the ulnar nerve, extensive neurolysis with a subsequent free gracilis muscle flap coverage shows a promising reduction of pain that persists at long-term follow-up.Level of evidence: IV.

Sexually Dimorphic Pattern of Pain Mitigation Following Prophylactic Regenerative Peripheral Nerve Interface (RPNI) in a Rat Neuroma Model

BACKGROUND

Treating neuroma pain is a clinical challenge. Identification of sex-specific nociceptive pathways allows a more individualized pain management. The Regenerative Peripheral Nerve Interface (RPNI) consists of a neurotized autologous free muscle using a severed peripheral nerve to provide physiological targets for the regenerating axons.

OBJECTIVE

To evaluate prophylactic RPNI to prevent neuroma pain in male and female rats.

METHODS

F344 rats of each sex were assigned to neuroma, prophylactic RPNI, or sham groups. Neuromas and RPNIs were created in both male and female rats. Weekly pain assessments including neuroma site pain and mechanical, cold, and thermal allodynia were performed for 8 weeks. Immunohistochemistry was used to evaluate macrophage infiltration and microglial expansion in the corresponding dorsal root ganglia and spinal cord segments.

RESULTS

Prophylactic RPNI prevented neuroma pain in both sexes; however, female rats displayed delayed pain attenuation when compared with males. Cold allodynia and thermal allodynia were attenuated exclusively in males. Macrophage infiltration was mitigated in males, whereas females showed a reduced number of spinal cord microglia.

CONCLUSION

Prophylactic RPNI can prevent neuroma site pain in both sexes. However, attenuation of both cold allodynia and thermal allodynia occurred in males exclusively, potentially because of their sexually dimorphic effect on pathological changes of the central nervous system.

Preventive Effect of Local Lidocaine Administration on the Formation of Traumatic Neuroma

BACKGROUND

Traumatic neuroma is a common sequela of peripheral nerve injury or amputation, which often leads to severe neuropathic pain. The present study investigated the effect of local lidocaine administration on preventing the formation of traumatic neuroma.

METHODS

Forty-eight male Sprague-Dawley rats were randomly assigned to two groups. The lidocaine group underwent sciatic nerve transection, followed by an injection of lidocaine (0.5%) around the proximal of a severed sciatic nerve under ultrasound-guidance 2-7 days after neurectomy. In the control group, rats received an injection of saline following neurectomy. The autotomy score, mechanical allodynia, thermal hyperalgesia, histological assessment, expression of neuroma, and pain-related markers were detected.

RESULTS

Lidocaine treatment reduced the autotomy score and attenuated mechanical allodynia and thermal hyperalgesia. The mRNA expression of α-SMA, NGF, TNF-α, and IL-1β all significantly decreased in the lidocaine group in comparison to those in the saline control group. The histological results showed nerve fibers, demyelination, and collagen hyperplasia in the proximal nerve stump in the saline control group, which were significantly inhibited in the lidocaine group.

CONCLUSIONS

The present study demonstrated that local lidocaine administration could inhibit the formation of painful neuroma due to traumatic nerve injury.

Hopeless Neuroma-The Neurotized Free Flap Tissue Augmentation as Salvage Therapy-A Concept and Clinical Demonstration

Therapy-resistant neuroma pain is a devastating condition for patients and surgeons. Although various methods are described to surgically deal with neuromas, some discontinuity and stump neuroma therapies have anatomical limitations. It is widely known that a neurotizable target for axon ingrowth is beneficial for dealing with neuromas. The nerve needs "something to do". Furthermore, sufficient soft tissue coverage plays a major role in sufficient neuroma therapy. We aimed, therefore, to demonstrate our approach for therapy of resistant neuromas with insufficient tissue coverage using free flaps, which are sensory neurotized via anatomical constant branches. The central idea is to provide a new target, a new "to do" for the painful mislead axons, as well as an augmentation of deficient soft tissues. As indication is key, we furthermore demonstrate clinical cases and common neurotizable workhorse flaps.

A cohort study on neuropathic pain of the saphenous nerve—factors influencing surgical outcome

Background

Due to its partially superficial course, the saphenous nerve is vulnerable to injury by trauma or surgery potentially leading to painful neuroma formation. Different surgical techniques to treat neuroma have been described, but so far, no one has proven to be superior to the others. The aim of this study was therefore to identify factors influencing the outcome of revision surgery in saphenous nerve neuropathic pain in our department.

Methods

From 2010 to 2020, a total of 29 consecutive patients with neuropathic pain and suspected neuroma of the saphenous nerve underwent revision surgery. A medical chart review was performed to collect patient-, pain-, and treatment-specific factors. Outcomes were registered.

Results

Post revision surgery in neuropathic pain of the saphenous nerve, 16 (55.2%) patients suffered from persisting pain. In multivariable logistic regression models evaluating the risk of persisting pain post saphenous nerve revision surgery, both smoking and preoperative opiate consumption represented independent predictors of higher risk for persisting pain.

Conclusions

Patients with injury to the saphenous nerve should be coached toward smoking cessation. Whenever possible, forgoing opiate treatment might be beneficial.

Level of evidence: Level IV, Risk/Prognostic.

Treatment of Refractory Radial Sensory Neuroma With Function-Sparing Targeted Muscle Reinnervation to the Extensor Carpi Radialis Brevis

The radial sensory nerve can be injured during many common procedures, including intravenous cannulation, first extensor compartment release, and radial-sided wrist surgery. Injury to the nerve may result in neuroma formation that can lead to chronic and debilitating pain. Nonsurgical treatments and surgical interventions, including excision of the neuroma and burying the nerve into local muscle, are frequently ineffective. Here, we present a technique for treating recalcitrant neuromas of the radial sensory nerve with targeted muscle reinnervation to a redundant motor nerve branch of the extensor carpi radialis brevis.

Long-Term Opioid Use Following Surgery for Symptomatic Neuroma

BACKGROUND

 Identifying patients at risk for prolonged opioid use following surgery for symptomatic neuroma would be beneficial for perioperative management. The aim of this study is to identify the factors associated with postoperative opioid use of >4 weeks in patients undergoing neuroma surgery.

METHODS

 After retrospective identification, 77 patients who underwent surgery for symptomatic neuroma of the upper or lower extremity were enrolled. Patients completed the Patient-Reported Outcomes Measurement Information System (PROMIS) depression, Numeric Rating Scale (NRS) pain score, and a custom medication questionnaire at a median of 9.7 years (range: 2.5-16.8 years) following surgery. Neuroma excision followed by nerve implantation (n = 39, 51%), nerve reconstruction/repair (n = 18, 23%), and excision alone (n = 16, 21%) were the most common surgical treatments.

RESULTS

 Overall, 27% (n = 21) of patients reported opioid use of more than 4 weeks postoperatively. Twenty-three patients (30%) reported preoperative opioid use of which 11 (48%) did not report opioid use for >4 weeks, postoperatively. In multivariable logistic regression, preoperative opioid use was independently associated with opioid use of >4 weeks, postoperatively (odds ratio [OR] = 4.4, 95% confidence interval [CI]: 1.36-14.3, p = 0.013).

CONCLUSION

 Neuroma surgery reduces opioid use in many patients but patients who are taking opioids preoperatively are at risk for longer opioid use. Almost one-third of patients reported opioid use longer than 4 weeks, postoperatively.

Beyond the Knife-Reviewing the Interplay of Psychosocial Factors and Peripheral Nerve Lesions

Peripheral nerve injuries are a common clinical problem. They not only affect the physical capabilities of the injured person due to loss of motor or sensory function but also have a significant impact on psychosocial aspects of life. The aim of this work is to review the interplay of psychosocial factors and peripheral nerve lesions. By reviewing the published literature, we identified several factors to be heavily influenced by peripheral nerve lesions. In addition to psychological factors like pain, depression, catastrophizing and stress, social factors like employment status and worker's compensation status could be identified to be influenced by peripheral nerve lesions as well as serving as predictors of functional outcome themselves, respectively. This work sheds a light not only on the impact of peripheral nerve lesions on psychosocial aspects of life, but also on the prognostic values of these factors of functional outcome. Interdisciplinary, individualized treatment of patients is required to identify patient at risk for adverse outcomes and provide them with emotional support when adapting to their new life situation.

Regenerative Peripheral Nerve Interfaces for the Treatment and Prevention of Neuromas and Neuroma Pain

A neuroma occurs when a regenerating transected peripheral nerve has no distal target to reinnervate. This situation can result in a hypersensitive free nerve ending that causes debilitating pain to affected patients. No techniques to treat symptomatic neuromas have shown consistent results. One novel physiologic solution is the regenerative peripheral nerve interface (RPNI). RPNI consists of a transected peripheral nerve that is implanted into an autologous free skeletal muscle graft. Early clinical studies have shown promising results in the use of RPNIs to treat and prevent symptomatic neuromas. This review article describes the rationale behind the success of RPNIs and its clinical applications.

Long-Term Outcomes after Surgical Treatment of Radial Sensory Nerve Neuromas: Patient-Reported Outcomes and Rate of Secondary Surgery

BACKGROUND

This study aimed to (1) describe long-term patient-reported outcomes of surgically treated symptomatic radial sensory nerve neuromas on function, pain interference, pain intensity, and satisfaction; (2) assess which factors were associated with worse function, higher pain intensity, and more pain interference; and (3) describe the secondary surgery rate and factors associated with secondary surgery.

METHODS

The authors conducted a retrospective review of patients surgically treated for radial sensory nerve neuroma from 2002 to 2016 (n = 54). Twenty-five of these 54 patients completed a follow-up survey including the Patient-Reported Outcomes Measurement Information System (PROMIS) upper extremity, pain interference, and depression scales; numerical rating scale pain and satisfaction instruments; and the global rating scale of change, at a mean period of 10.7 ± 4.3 years after neuroma surgery.

RESULTS

The mean PROMIS scores were 45.0 ± 12.1 for upper extremity, 55.5 ± 10.3 for pain interference, and 49.9 ± 10.2 for depression, and were within 1 SD of the general population. Eight patients (32 percent) reported symptoms as unchanged or worse following neuroma surgery. The median numerical rating scale pain was 3 (interquartile range, 1 to 6) and the global rating scale of change satisfaction was 10 (interquartile range, 7 to 10). Older patients (p = 0.002) and patients with higher PROMIS pain interference (p < 0.001), higher numerical rating scale for pain (p = 0.012), and lower global rating scale of change scores (p = 0.01) had worse PROMIS upper extremity scores. The secondary surgery rate was 20 percent and was associated with the presence of multiple neuromas (p = 0.001).

CONCLUSIONS

Radial sensory nerve neuromas remain difficult to treat. They have a high secondary surgery rate (20 percent), with only 68 percent of patients reporting improvement after surgical intervention. Patient-reported outcomes after surgery are similar to conditions of the general population; however, the range of outcomes is wide.

Free muscle flap coverage as last resort for therapy-resistant neuropathic pain in the upper extremity: A long-term retrospective follow-up study

BACKGROUND

Persistent neuropathic pain severely impacts physical functioning and quality of life (QoL). However, optimal surgical management of persistent neuropathic pain remains unclear. Extensive neurolysis with subsequent free muscle flap coverage, a new surgical procedure for neuropathic pain in the upper extremity, can be performed as a final option to establish pain reduction.

METHODS

All consecutive patients who received extensive microsurgical neurolysis with subsequent free muscle flap for persistent neuropathic pain in the upper extremity between 2007 and 2014 were identified. Patient-reported upper extremity function and QoL were assessed using three questionnaires (36-item short-form health survey (SF-36), the disabilities of the arm, shoulder, and head questionnaire, and the Michigan hand outcomes questionnaire).

RESULTS

Fifteen patients were identified; 80% had neuropathic pain in the upper extremity due to nerve injury and a median of 3.0 previous surgeries (range 1-6). Sixty-seven percent developed some kind of complication, flap loss occurred in 22%, and all received a new free flap (one failed again). At last follow-up, pre- and postoperative visual analog scale (VAS) scores significantly differed (p = 0.002), and the median VAS at last follow-up was 1.5. Ten patients (67%) responded to the questionnaires after a median follow-up of 5.7 year (range 2.6-7.3 years). Patients on average reported poorer SF-36 "Physical Component Score" (PCS) and "Bodily Pain" compared to Dutch norms. Forty percent of patients reported still having always (very) severe pain. However, 64% had a postoperative decrease of at least 3.0 on VAS.

CONCLUSION

Extensive neurolysis with free muscle flap coverage for persistent neuropathic pain in the upper extremity showed a positive effect on pain reduction on short-term follow-up, and also at five-year follow-up. The impact of pain on functional outcomes remained. Nevertheless, 60% of the patients still experience sufficient pain reduction.

The Role of Fat Grafting in Alleviating Neuropathic Pain: A Critical Review of the Literature

Background

Neuropathic pain is one of the more severe types of chronic pain and presents a great challenge as response to medical therapy remains often unpredictable. With the opioid epidemic and the search for ways to avoid narcotics, physicians are seeking other modalities to treat neuropathic pain. In recent years, surgeons have explored various surgical avenues to improve outcomes. The aim of this review was to evaluate the current clinical evidence regarding the efficacy of fat grafting for the treatment of neuropathic pain.

Methods

A critical review was conducted to examine the current clinical evidence of fat grafting as a therapy for neuropathic pain caused by neuromas, peripheral neuralgia, migraine and headaches, neuropathic scar pain, and postmastectomy pain syndrome.

Results

The precise mechanism role of fat grafting in modulating neuropathic pain remains unclear, but it appears to reduce pain levels through the anti-inflammatory effects of adipose-derived stem cells and mechanical cushioning by fat.

Conclusions

Fat grafting is an emerging therapy for chronic neuropathic pain of various etiologies. Although promising results have been reported, sample size and level of evidence of current studies are low. The encouraging results, however, are worthy of further clinical and scientific study. The minimally invasive nature of fat grafting and favorable risk profile make this an attractive therapy for neuropathic pain.

Etiology and Treatment Outcomes for Sural Neuroma

BACKGROUND

Neuroma results from disorganized regeneration following nerve injury and may be symptomatic. The aim of this study was to investigate the causes, treatment, and outcomes of operatively treated sural neuromas, and to describe the factors associated with persistent or unchanged postoperative pain symptoms.

METHODS

Consecutive patients with surgically treated sural neuromas in a 14-year period were identified using Current Procedural Terminology (CPT) codes ( n = 49), followed by a chart review to collect patient and treatment characteristics. Postoperative pain symptoms were categorized as complete resolution of pain, improvement of pain, no change in pain, or worse pain. The median patient age was 46.5 years (interquartile range [IQR], 39.1-51.3), and median follow-up was 4.0 years (IQR, 1.9-9.2).

RESULTS

Ninety percent of symptomatic sural neuromas developed as a result of previous lower extremity surgery. Initial surgery of sural neuroma led to improvement in pain in 63% of patients, and an additional 8.2% of the patients had improvement after secondary neuroma surgery. Pain relief after diagnostic injection showed a trend toward an association with postoperative pain improvement. Neuroma excision and implantation in muscle was the most common surgical technique used (67%). Four of the 7 patients that underwent a second neuroma operation reported symptom improvement.

CONCLUSION

Sural neuromas may arise from prior surgery or trauma to the lower extremity. Surgical intervention resulted in either improvement or complete resolution of pain symptoms in 71% of patients, although occasionally more than one procedure was required to obtain symptomatic relief. Preoperative anesthetic injection may help identify patients that benefit from neuroma surgery. Level of Evidence: Level IV, retrospective case series.

Management of the sciatic nerve during transfemoral amputation: a survey of Dutch surgeons

BACKGROUND

Neuropathic pain often occurs after leg amputation. It is unclear why some patients suffer from pain and others do not. Intraoperative nerve handling might correlate with these pain syndromes. It is unknown which nerve handling techniques are currently used among surgeons and whether a specific technique is related to eliciting these pain syndromes. The aim of this study was to investigate the current surgical sciatic nerve management used among surgeons in the Netherlands.

METHODS

A survey was carried out among Dutch surgeons. Additionally, surgical sciatic nerve management data were obtained from the surgical reports of transfemoral amputations that were performed in our hospital.

RESULTS

Seventy-eight of the 102 online surveys were returned. Sharp transection without ligation was used most often (41.0%), followed by sharp transection after ligation (30.8%). There were 38 transfemoral amputations performed in our hospital. Sharp transection after ligation was most often used (55.3%), followed by transection with electrocautery (13.2%).

CONCLUSIONS

All techniques of transecting the sciatic nerve are currently performed by Dutch surgeons. These results provide a solid basis to perform future studies to investigate whether a specific surgical technique is related to postamputation pain syndromes.

The Possible Preventive Role of Pregabalin in Postmastectomy Pain Syndrome: A Double-Blinded Randomized Controlled Trial

CONTEXT

Chronic postmastectomy pain syndrome (PMPS) has a considerable negative impact on the quality of life of breast cancer patients.

OBJECTIVE

The objective of this study was to assess the possible preventive role of perioperative pregabalin in PMPS.

METHODS

This randomized controlled study included 200 patients with breast cancer scheduled for elective breast cancer surgery. They were randomly assigned to one of two treatment groups. The pregabalin group received 75 mg of pregabalin twice daily for seven days and the control group received oral equivalent placebo capsules. The primary outcome was development of neuropathic PMPS. Neuropathic pain was assessed using the Grading System for Neuropathic Pain. Secondary outcome measures were safety and Visual Analogue Scale scores.

RESULTS

Neuropathic pain was significantly less frequent in the pregabalin group compared to the control group at four weeks (P = 0.005), 12 weeks (P = 0.002), and 24 weeks (P < 0.001) postoperatively. PMPS was diagnosed in 11 patients (11%) of the pregabalin group and 29 patients (29%) of the control group (P < 0.001, relative risk: 0.26, 95% CI: 0.12-0.56). At the three follow-up time points, Visual Analogue Scale scores during the first three postoperative weeks were comparable in both groups while they were significantly lower in the pregabalin group at 4, 12, and 24 weeks. These two groups were comparable in the frequency of adverse events (P = 0.552).

CONCLUSION

Perioperative oral pregabalin 75 mg twice daily, starting at the morning of surgery and continued for one week, could reduce the frequency of postmastectomy pain syndrome.

Surgical Algorithm for Neuroma Management: A Changing Treatment Paradigm

Successful treatment of the painful neuroma is a particular challenge to the nerve surgeon. Historically, symptomatic neuromas have primarily been treated with excision and implantation techniques, which are inherently passive and do not address the terminal end of the nerve. Over the past decade, the surgical management of neuromas has undergone a paradigm shift synchronous with the development of contemporary techniques aiming to satisfy the nerve end. In this article, we describe the important features of surgical treatment, including the approach to diagnosis with consideration of neuroma type and the decision of partial versus complete neuroma excision. A comprehensive list of the available surgical techniques for management following neuroma excision is presented, the choice of which is often predicated upon the availability of the terminal nerve end for reconstruction. Techniques for neuroma reconstruction in the presence of an intact terminal nerve end include hollow tube reconstruction and auto- or allograft nerve reconstruction. Techniques for neuroma management in the absence of an intact or identifiable terminal nerve end include submuscular or interosseous implantation, centro-central neurorrhaphy, relocation nerve grafting, nerve cap placement, use of regenerative peripheral nerve interface, "end-to-side" neurorrhaphy, and targeted muscle reinnervation. These techniques can be further categorized into passive/ablative and active/reconstructive modalities. The nerve surgeon must be aware of available treatment options and should carefully choose the most appropriate intervention for each patient. Comparative studies are lacking and will be necessary in the future to determine the relative effectiveness of each technique.

Surgical Algorithm for Neuroma Management: A Changing Treatment Paradigm

Successful treatment of the painful neuroma is a particular challenge to the nerve surgeon. Historically, symptomatic neuromas have primarily been treated with excision and implantation techniques, which are inherently passive and do not address the terminal end of the nerve. Over the past decade, the surgical management of neuromas has undergone a paradigm shift synchronous with the development of contemporary techniques aiming to satisfy the nerve end. In this article, we describe the important features of surgical treatment, including the approach to diagnosis with consideration of neuroma type and the decision of partial versus complete neuroma excision. A comprehensive list of the available surgical techniques for management following neuroma excision is presented, the choice of which is often predicated upon the availability of the terminal nerve end for reconstruction. Techniques for neuroma reconstruction in the presence of an intact terminal nerve end include hollow tube reconstruction and auto- or allograft nerve reconstruction. Techniques for neuroma management in the absence of an intact or identifiable terminal nerve end include submuscular or interosseous implantation, centro-central neurorrhaphy, relocation nerve grafting, nerve cap placement, use of regenerative peripheral nerve interface, “end-to-side” neurorrhaphy, and targeted muscle reinnervation. These techniques can be further categorized into passive/ablative and active/reconstructive modalities. The nerve surgeon must be aware of available treatment options and should carefully choose the most appropriate intervention for each patient. Comparative studies are lacking and will be necessary in the future to determine the relative effectiveness of each technique.

Time course of traumatic neuroma development

This study was designed to characterize morphologic stages during neuroma development post amputation with an eye toward developing better treatment strategies that intervene before neuromas are fully formed. Right forelimbs of 30 Sprague Dawley rats were amputated and limb stumps were collected at 3, 7, 28, 60 and 90 Days Post Amputation (DPA). Morphology of newly formed nerves and neuromas were assessed via general histology and neurofilament protein antibody staining. Analysis revealed six morphological characteristics during nerve and neuroma development; 1) normal nerve, 2) degenerating axons, 3) axonal sprouts, 4) unorganized bundles of axons, 5) unorganized axon growth into muscles, and 6) unorganized axon growth into fibrotic tissue (neuroma). At early stages (3 & 7 DPA) after amputation, normal nerves could be identified throughout the limb stump and small areas of axonal sprouts were present near the site of injury. Signs of degenerating axons were evident from 7 to 90 DPA. From day 28 on, variability of nerve characteristics with signs of unorganized axon growth into muscle and fibrotic tissue and neuroma formation became visible in multiple areas of stump tissue. These pathological features became more evident on days 60 and 90. At 90 DPA frank neuroma formation was present in all stump tissue. By following nerve regrowth and neuroma formation after amputation we were able to identify 6 separate histological stages of nerve regrowth and neuroma development. Axonal regrowth was observed as early as 3 DPA and signs of unorganized axonal growth and neuroma formation were evident by 28 DPA. Based on these observations we speculate that neuroma treatment and or prevention strategies might be more successful if targeted at the initial stages of development and not after 28 DPA.

Painful Terminal Neuroma Prevention by Capping PRGD/PDLLA Conduit in Rat Sciatic Nerves

Neuroma formation after amputation as a long-term deficiency leads to spontaneous neuropathic pain that reduces quality of life of patients. To prevent neuroma formation, capping techniques are implemented as effective treatments. However, an ideal, biocompatible material covering the nerves is an unmet clinical need. In this study, biocompatible characteristics presented by the poly(D,L-lactic acid)/arginylglycylaspartic acid (RGD peptide) modification of poly{(lactic acid)-co- [(glycolic acid)-alt-(L-lysine)]} (PRGD/PDLLA) are evaluated as a nerve conduit. After being capped on the rat sciatic nerve stump in vivo, rodent behaviors and tissue structures are compared via autotomy scoring and histological analyses. The PRGD/PDLLA capped group gains lower autotomy score and improves the recovery, where inflammatory infiltrations and excessive collagen deposition are defeated. Transmission electron microscopy images of the regeneration of myelin sheath in both groups show that abnormal myelination is only present in the uncapped rats. Changes in related genes (MPZ, MBP, MAG, and Krox20) are monitored quantitative real-time polymerase chain reaction (qRT-PCR) for mechanism investigation. The PRGD/PDLLA capping conduits not only act as physical barriers to inhibit the invasion of inflammatory infiltration in the scar tissue but also provide a suitable microenvironment for promoting nerve repairing and avoiding neuroma formation during nerve recovery.

Pro and anti-inflammatory cytokine levels (TNF-α, IL-1β, IL-6 and IL-10) in rat model of neuroma

Traumatic neuroma is neuronal tissue proliferation developed in a nerve injury site, often associated with increased sensitivity and spontaneous or evoked neuropathic pain. The mechanisms leading to the disorganized nerve proliferation are not completely understood, though inflammation in the injured nerve vicinity most likely has a role in the process. Inflammatory cytokines are also known to be involved in the maintenance and development of post-traumatic and neuropathic pain. The goal of this study was to quantify and compare pro and anti-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-10) levels in nerves that formed neuromas and nerves that did not, following sciatic nerve transection. A total of 30 rats were used in this study. Twenty rats underwent sciatic nerve transection and 10 underwent sham surgery. Six weeks post-surgery nerve sections were collected and histologically evaluated for neuroma formation. The samples were then classified as neuroma, non-neuroma and sham groups. TNF-α, IL-1β, IL-6 and IL-10 levels were measured in the nerves employing ELISA. TNF-α levels were significantly higher in both neuroma and non-neuroma-forming injured nerves compared to the sham group. IL-1β and IL-6 levels were significantly higher in the neuroma-forming nerves compared to the sham group. IL-10 levels were significantly higher in the non-neuroma group compared to the sham group. In conclusion IL-6, and IL-1 β may have a role in the formation of traumatic neuroma while IL-10 may inhibit neuroma formation.

Traumatic neuroma of the superficial peroneal nerve in a patient: a case report and review of the literature

BACKGROUND

Traumatic neuromas are rare benign tumors, which are common in trauma or post-operation and accompanied with obvious symptoms of pain. This study will show the superficial peroneal nerve neuroma occurring after resection of hemangioma.

CASE PRESENTATION

A 44-year-old male had an operation of the right leg cavernous hemangioma resection in 1995. Half a year after the operation, pain around the wound appeared and gradually aggravated. The patient had the lesion exploration resection in 2013, and the pathological result showed traumatic neuroma. Within half a year of the second operation, severe pain showed up again, so neuroma resection proceeded in May 2015. The postoperative pathological and immunohistochemical results showed traumatic neuroma. According to the postoperative follow-up, there were no symptoms of pain appearing again.

LITERATURE REVIEW

The pain is obvious, and B ultrasonography is the most efficient way to find neuromas. Both conservative and operative therapy have their advantages and disadvantages.

CONCLUSIONS

There remain many unanswered questions in relation to the treatment of traumatic neuromas, and further research is required, although we have already had adequate understanding of traumatic neuromas.

Traction Neurectomy for Treatment of Painful Residual Limb Neuroma in Lower Extremity Amputees

OBJECTIVES

To describe the outcomes of traction neurectomy as a surgical treatment for symptomatic neuroma of the residual lower extremity and to identify clinical and/or demographic factors associated with an increased likelihood of persistent or recurrent pain after surgery.

DESIGN

Retrospective Cohort Study.

SETTING

Amputee clinic at a Level I Trauma Center.

PATIENTS

Inclusion required a history of transfemoral or transtibial amputation and a history of symptomatic neuroma(s) at the residual limb treated with traction neurectomy. Twelve months of clinical follow-up or the recurrence of neuroma-type pains was required for inclusion. Thirty-eight patients (63 nerves) comprised the study group.

INTERVENTION

Traction neurectomy for treatment of symptomatic neuroma.

MAIN OUTCOME MEASURES

The primary outcome was the presence or absence of persistent or recurrent neuroma-type pain at last follow-up. The secondary outcome was reoperation for persistent or recurrent symptomatic neuroma.

RESULTS

Sixteen of 38 patients (42%) had recurrent or persistent neuroma-type pain at a mean follow-up of 37 months (range, 11-91 months), and 8/38 (21%) have undergone subsequent surgical treatment. Among the demographic and clinical features examined, only male gender was found to be a statistically significant predictor of persistent or recurrent neuroma-type pain.

CONCLUSIONS

Traction neurectomy results in a high rate of persistent or recurrent neuroma-type and that surgeons should be cautious when considering it for the treatment of symptomatic neuroma of the residual lower extremity. Furthermore, efforts to identify better surgical and nonsurgical treatments for this problem are justified.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Interdigital direct neurorrhaphy for treatment of painful neuroma due to finger amputation

BACKGROUND

Painful neuroma following amputation is a disabling condition for which treatments are not usually satisfactory. The aim of this study is to retrospectively evaluate the results of interdigital neurorrhaphy after neuroma resection as an option for the surgical treatment of painful digital neuroma.

METHOD

We retrospectively analyzed data from seven patients submitted to interdigital neurorrhaphy for treatment of digital neuroma. For evaluation of the results, the visual analog scale (VAS) for pain assessment, measurements with Simmens-Weinstein filaments and a handgrip dynamometer, and quantification of the Disabilities of the Arm, Shoulder and Hand (DASH) score were all performed. The mean improvements on the VAS and DASH scores were calculated.

RESULTS

The mean follow-up was 28.3 months. All patients presented some degree of improvement in upper limb functionality and pain, and handling the affected finger was possible in all cases. The mean improvement on the VAS and DASH scores was 29.8 and 55.5 %, respectively. No patients presented long-term complications.

CONCLUSION

Although this study was based on a small number of patients, it indicates that interdigital neurorrhaphy seems to be a feasible surgical treatment for painful digital neuroma.

Joint denervation and neuroma surgery as joint-preserving therapy for ankle pain

Partial joint denervation or surgical neuroma therapy are alternative concepts to treat pain around the ankle joint that preserve joint function and relieve pain by interrupting neural pathways that transmit pain impulses from the joint to the brain. This review article summarizes the indication, anatomic background, operative techniques, and clinical results of joint denervation or neuroma surgery, which, although rarely reported and used, may provide a valuable alternative treatment in selected patients with neurogenous problems around the ankle.

Perioperative interventions to reduce chronic postsurgical pain

Approximately 10% of patients following a variety of surgeries develop chronic postsurgical pain. Reducing chronic postoperative pain is especially important to reconstructive surgeons because common operations such as breast and limb reconstruction have even higher risk for developing chronic postsurgical pain. Animal studies of posttraumatic nerve injury pain demonstrate that there is a critical time frame before and immediately after nerve injury in which specific interventions can reduce the incidence and intensity of chronic neuropathic pain behaviors-so called "preventative analgesia." In animal models, perineural local anesthetic, systemic intravenous local anesthetic, perineural clonidine, systemic gabapentin, systemic tricyclic antidepressants, and minocycline have each been shown to reduce pain behaviors days to weeks after treatment. The translation of this work to humans also suggests that brief perioperative interventions may protect patients from developing new chronic postsurgical pain. Recent clinical trial data show that there is an opportunity during the perioperative period to dramatically reduce the incidence and severity of chronic postsurgical pain. The surgeon, working with the anesthesiologist, has the ability to modify both early and chronic postoperative pain by implementing an evidence-based preventative analgesia plan.

Painful neuromas

OBJECTIVES

To perform a topical review of the published literature on painful neuromas.

METHODS

A MEDLINE search was performed using the MESH terms "neuroma", "pain", "diagnosis", and "treatment" for all dates.

RESULTS

Acoustic neuromas and intraabdominal neuromas were excluded from a total of 7616 articles. The reference lists from these articles were further reviewed to obtain other relevant articles.

DISCUSSION

Neuromas develop as part of a normal reparative process following peripheral nerve injury. Painful neuromas can induce intense pain resulting in immense suffering and disability. MRI aids the diagnosis, but, ultrasound imaging allows cost effective accurate diagnosis and localization of neuromas by demonstrating their direct contiguity with the nerve of origin. Management options for painful neuromas include pharmacotherapy, prosthetic adjustments, steroid injection, chemical neurolysis, cryoablation, and radiofrequency ablation. Ultrasound imaging guidance has improved the success in localizing and targeting the neuromas. This review discusses the patho-physiology and accumulated evidence for various therapies and the current percutaneous interventional management options for painful neuromas.

Surgical management of neuroma pain: a prospective follow-up study

Painful neuromas can cause severe loss of function and have great impact on the daily life of patients. Surgical management remains challenging; despite improving techniques, success rates are low. To accurately study the success of surgical neuroma treatment and factors predictive of outcome, a prospective follow-up study was performed. Between 2006 and 2009, pre- and post-operative questionnaires regarding pain (VAS, McGill), function (DASH), quality of life (SF-36), symptoms of psychopathology (SCL-90), epidemiologic determinants and other outcome factors were sent to patients surgically treated for upper extremity neuroma pain. Pain scores after diagnostic nerve blocks were documented at the outpatient clinic before surgery. Thirty-four patients were included, with an average follow up time of 22 months. The mean VAS score decreased from 6.8 to 4.9 after surgery (p<0.01), 19 (56%) of patients were satisfied with surgical results. Upper extremity function improved significantly (p=0.001). Neuroma patients had significantly lower quality of life compared to a normal population. Employment status, duration of pain and CRPS symptoms were found to be prognostic factors. VAS scores after diagnostic nerve block were predictive of post-operative VAS scores (p=0.001). Furthermore, smoking was significantly related to worse outcome (relative risk: 2.10). The results could lead to improved patient selection and treatment strategies. If a diagnostic nerve block is ineffective in relieving pain, patients will most likely not benefit from surgical treatment. Patients should be encouraged to focus on activity and employment instead of their symptoms. Smoking should be discouraged in patients who will undergo surgical neuroma treatment.