Ultrasound Findings of Young and Traumatic Amputees With Lower Extremity Residual Limb Pain in Turkey

Regenerative Peripheral Nerve Interface Surgery for the Management of Chronic Posttraumatic Neuropathic Pain

Chronic pain resulting from peripheral nerve injury remains a common issue in the United States and affects 7 to 10% of the population. Regenerative Peripheral Nerve Interface (RPNI) surgery is an innovative surgical procedure designed to treat posttraumatic neuropathic pain, particularly when a symptomatic neuroma is present on clinical exam. RPNI surgery involves implantation of a transected peripheral nerve into an autologous free muscle graft to provide denervated targets to regenerating axons. RPNI surgery has been found in animal and human studies to be highly effective in addressing postamputation pain. While most studies have reported its uses in the amputation patient population for the treatment of neuroma and phantom limb pain, RPNI surgery has recently been used to address refractory headache, postmastectomy pain, and painful donor sites from the harvest of neurotized flaps. This review summarizes the current understanding of RPNI surgery for the treatment of chronic neuropathic pain.

Regenerative peripheral nerve interface reduces the incidence of neuroma in the lower limbs after amputation: a retrospective study based on ultrasound

BACKGROUND

Amputees suffer from symptomatic neuroma and phantom limb pain. Regenerative peripheral nerve interface (RPNI) has recently been regarded as an effective method to prevent neuroma after amputation. However, the verifications of RPNI efficacy are mostly based on subjective evaluation, lacking objective approaches. This study aims to unveil the effect of RPNI on preventing neuroma formation and provide evidence supporting the efficacy of RPNI based on ultrasound.

METHODS

Amputees of lower limb at Peking University People's Hospital from July 2020 to March 2022 were analyzed retrospectively. The clinical data collected consisted of general information, pathology of primary disease, history of limb-salvage treatment, amputation level of nerve, pain scales such as the Numerical Rating Scale (NRS) and the Manchester Foot Pain and Disability Index (MFPDI). Three months after amputation, the transverse diameter, anteroposterior diameter, and cross-sectional area of neuromas in stump nerves at the end of residual limbs were measured using ultrasound and compared to adjacent normal nerves.

RESULTS

Fourteen patients were enrolled in the study, including 7 in the traditional amputation group (TA group) and 7 in the RPNI group. There was no significant difference in basic information and amputation sites between the two groups. The NRS and MFPDI scores of patients in RPNI group were significantly lower than those in TA group, and decreased with the follow-up time increasing, indicating that RPNI could reduce symptomatic neuroma pain. The comparison of preoperative ultrasound and postoperative pathology showed ultrasound could reflect the size of neuroma in vivo. Independent-sample t tests indicated that the ratios of anteroposterior diameter, transverse diameter and area of the cross section of both the neuroma and adjacent normal nerve obtained via ultrasound were significantly reduced in the RPNI group.

CONCLUSION

This study suggested that RPNI can effectively prevent the formation of symptomatic neuroma after amputation using ultrasound.

Osseointegration for Lower Limb Amputation: Understanding the Risk Factors and Time Courses of Soft Tissue Complications

PURPOSE

Lower-limb osseointegrated prostheses are a novel alternative to traditional socket-suspended prostheses, which are often associated with poor fit, soft tissue damage, and pain. Osseointegration eliminates the socket-skin interface and allows for weight-bearing directly on the skeletal system. However, these prostheses can also be complicated by postoperative issues that can negatively impact mobility and quality of life. Little is known about the incidence of or risk factors for these complications as few centers currently perform the procedure.

METHODS

A retrospective analysis was performed on all patients who underwent single-stage lower limb osseointegration at our institution between 2017 and 2021. Patient demographics, medical history, operative data, and outcomes were collected. Fisher exact test and unpaired t tests were performed to identify risk factors for each adverse outcome, and time-to-event survival curves were generated.

RESULTS

Sixty patients met our study criteria: 42 males and 18 females with 35 transfemoral and 25 transtibial amputations. The cohort had an average age of 48 years (range, 25-70 years) and follow-up period of 22 months (range, 6-47 months). Indications for amputation were trauma (50), prior surgical complication (5), cancer (4), and infection (1). Postoperatively, 25 patients developed soft tissue infections, 5 developed osteomyelitis, 6 had symptomatic neuromas, and 7 required soft tissue revisions. Soft tissue infections were positively correlated with obesity and female sex. Neuroma development was associated with increased age at osseointegration. Neuromas and osteomyelitis were both associated with decreased center experience. Subgroup analysis by amputation etiology and anatomic location did not show significant differences in outcomes. Notably, hypertension (15), tobacco use (27), and prior site infection (23) did not correlate with worse outcomes. Forty-seven percent of soft tissue infections occurred in the 1 month after implantation, and 76% occurred in the first 4 months.

CONCLUSIONS

These data provide preliminary insights into risk factors for postoperative complications arising from lower limb osseointegration. These factors are both modifiable (body mass index, center experience), and unmodifiable (sex, age). As this procedure continues to expand in popularity, such results are necessary to inform best practice guidelines and optimize outcomes. Further prospective studies are needed to confirm the above trends.

A Systematic Review and Meta-analysis on the Incidence of Patients With Lower-Limb Amputations Who Developed Symptomatic Neuromata in the Residual Limb

BACKGROUND

Neuromata developed after major extremity amputation can cause pain, limit the use of prosthetics, and negatively affect the quality of life. The frequency of postamputation neuroma varies widely. The objective of this study was to determine the incidence of patients who developed symptomatic neuromata after lower-limb amputation through a systematic review and meta-analysis.

METHODS

A systematic review of the literature was performed on 4 major databases. Studies that reported the incidence of symptomatic neuroma in lower-limb amputees were included. A meta-analysis was performed to calculate the pooled incidence of neuromata.

RESULTS

Thirteen studies consisting of 1329 patients were included in this meta-analysis. The reported incidence of patients who developed symptomatic neuromata ranged between 4% and 49%. The median duration of follow-up was 8.6 years (interquartile range, 2.0-17.4 years). The pooled percentage (95% confidence interval [CI]) of lower-limb amputees who developed symptomatic neuromata was 19% (12%-29%). In studies with a duration of follow-up at least 3 years, the pooled percentage (95% CI) of lower-limb amputees who developed symptomatic neuromata was 30% (22%-40%). In studies with a follow-up period of fewer than 3 years, the pooled percentage (95% CI) of neuroma incidence was 3% (2%-6%).

CONCLUSIONS

In summary, the overall incidence of patients who developed symptomatic neuromata was 19% or approximately 1 in 5 lower-limb amputees. Symptomatic neuromata are more commonly diagnosed when the follow-up period is longer than 3 years. These findings suggest that neuroma after amputation might be underestimated in studies with a short duration of follow-up.

Management of Phantom Limb Pain through Thalamotomy of the Centro-Median Nucleus

Background: Phantom limb syndrome is defined as the perception of intense pain or other sensations that are secondary to a neural lesion in a limb that does not exist. It can be treated using pharmacological and surgical interventions. Most medications are prescribed to improve patients’ lives; however, the response rate is low. In this case report, we present a case of phantom limb syndrome in a 42-year-old female with a history of transradial amputation of the left thoracic limb due to an accidental compression one year before. The patient underwent placement of a deep brain stimulator at the ventral posteromedial nucleus (VPM) on the right side and removal secondary to loss of battery. The patient continued to have a burning pain throughout the limb with a sensation of still having the limb, which was subsequently diagnosed as phantom limb syndrome. After a thorough discussion with the patient, a right stereotactic centro-median thalamotomy was offered. An immediate response was reported with a reduction in pain severity on the visual analogue scale (VAS) from a value of 9–10 preoperative to a value of 2 postoperative, with no postoperative complications. Although phantom limb pain is one of the most difficult to treat conditions, centro-median thalamotomy may provide an effective stereotactic treatment procedure with adequate outcomes.

Residual limb pain: An evidence-based review

Acquired limb loss, whether from accident or amputation, occurs with an incidence of greater than 175,000 per year in the United States. Current prevalence is estimated at greater than 1.5 million and is expected to double within 30 years. While many patients with amputations may have no significant pain or sensory issues after healing from the initial loss, one-quarter to one-half of patients may have ongoing difficulties with residual limb pain, phantom limb pain, or phantom limb sensation. This review explores the potential etiologies of those symptoms, as well as a variety of treatment options that a practitioner may consider when approaching this condition.

Neuromas and postamputation pain

Postamputation stump and phantom pain are highly prevalent but remain a difficult condition to treat. The underlying mechanisms are not fully clarified, but growing evidence suggests that changes in afferent nerves, including the formation of neuromas, play an important role. The main objective of this cross-sectional study was to investigate whether ultrasound-verified neuroma swellings are more frequent in amputees with postamputation pain than in amputees without pain (primary outcome). Sixty-seven amputees were included. Baseline characteristics including the frequency and intensity of spontaneous stump and phantom pain were obtained, and sensory characteristics and evoked responses were assessed. A high-frequency ultrasound examination of the amputated extremity was performed to obtain information on the presence, size, and elasticity of swollen neuromas and pressure pain thresholds. Swollen neuromas were present in 53 (79.1%) of the 67 amputees included in the study, in 47 (82.5%) of 57 amputees with pain and in 6 (60.0%) of 10 amputees without pain (P = 0.2). No difference was found in stump pain intensity (P = 0.42) during the last week or in phantom pain intensity in the last month (P = 0.74) between amputees with and without swollen neuromas. Our findings suggest that it is not the presence of swollen neuromas itself that drives postamputation pain. However, changes in the transected nerve endings may still be crucial for driving postamputation pain because a positive Tinel sign was significantly more frequent in amputees with pain, irrespectively of the degree of neuroma swelling.

Ultrasonography-Guided Radiofrequency Ablation for Painful Stump Neuromas to Relieve Postamputation Pain: A Pilot Study

Objective

Postamputation pain (PAP) is a serious problem, and thus far, there is no perfect treatment strategy. Clinically, minimally invasive treatments for peripheral neuromas are simple and feasible. This study aimed to investigate the immediate and long-term effects of ultrasonography-guided radiofrequency ablation (RFA) on PAP.

Methods

Eighteen PAP subjects with painful peripheral neuromas were treated with ultrasonography-guided RFA.

Results

A total of 18 PAP subjects were included in the final analyses. Fourteen of the 17 subjects with residual limb pain (RLP) (82.4%) had successful outcomes. A successful outcome was noted in 9 of the 13 subjects with phantom limb pain (PLP) (69.2%). There were no significant associations between symptom relief and sex, age, or the duration of symptoms. There were no severe complications.

Conclusions

Ultrasonography-guided RFA for painful stump neuromas can effectively relieve stump pain and PLP in amputees with PAP (follow-up time was 12 months). Ultrasonography-guided RFA is easy and safe and does not involve radiation exposure, making it very suitable for clinical applications.

Diagnostic Criteria for Symptomatic Neuroma

INTRODUCTION

After nerve injury, disorganized or incomplete nerve regeneration may result in a neuroma. The true incidence of symptomatic neuroma is unknown, and the diagnosis has traditionally been made based on patient history, symptoms, physical examination, and the anatomic location of pain, along with response to diagnostic injection. There are no formally accepted criteria for a diagnosis of neuroma.

MATERIALS AND METHODS

A literature search was performed to identify articles related to neuroma: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and Pubmed, Embase, and the Cochrane Library were searched for all relevant articles pertaining to neuroma. Articles were screened by title and abstract for relevance. If an article was considered potentially relevant, the full article was reviewed. After consideration, 50 articles were included in this systematic review.

RESULTS

No previous articles directly addressed diagnostic criteria for symptomatic neuroma. Factors related to neuroma diagnosis gleaned from previous studies include pain and cold intolerance (patient history), positive Tinel sign or diminished 2-point discrimination (physical examination findings), response to diagnostic nerve block, and presence of neuroma on diagnostic imaging (ultrasound or magnetic resonance imaging). Based on literature review, the importance and number of references, as well as clinical experience, we propose criteria for diagnosis of symptomatic neuroma. To receive a diagnosis of symptomatic neuroma, patients must have (1) pain with at least 3 qualifying "neuropathic" characteristics, (2) symptoms in a defined neural anatomic distribution, and (3) a history of a nerve injury or suspected nerve injury. In addition, patients must have at least 2 of the following 4 findings: (1) positive Tinel sign on examination at/along suspected nerve injury site, (2) tenderness/pain on examination at/along suspected nerve injury site, (3) positive response to a diagnostic local anesthetic injection, and (4) ultrasound or magnetic resonance imaging confirmation of neuroma.

CONCLUSIONS

The diagnosis of neuroma is based on a careful history and physical examination and should rely on the proposed criteria for confirmation. These criteria will be helpful in more precisely defining the diagnosis for clinical and research purposes.

Phantom limb pain: A literature review

Since the phantom limb sensation was first described by the French military surgeon Ambroise Pare in the 16th century, the number of studies surrounding phantom limb pain has increased every year. Especially in recent decades, scientists have achieved a better understanding of the mechanism and treatment of phantom limb pain. Although many hypotheses have been agreed and many treatments have been proven effective, scientists still do not have a very systematic understanding of the phantom limbs. The purpose of this review article is to summarize recent researches focusing on phantom limb in order to discuss its definition, mechanisms, and treatments.