The prevalence and risk factors for phantom limb pain in people with amputations: A systematic review and meta-analysis

Acute versus non-acute targeted muscle reinnervation for pain control following major limb amputation: A comparative study

BACKGROUND

Targeted muscle reinnervation (TMR) has been shown to reduce phantom limb pain (PLP) and residual limb pain (RLP) after major limb amputation. However, the effect of the timing of surgery on pain control and quality of life outcomes is controversial. We conducted a retrospective study to compare the outcomes of acute TMR for pain prevention with non-acute TMR for the treatment of established pain.

METHODS

All patients treated with TMR in our institution between January 2018 and December 2021 were evaluated at 6, 12, 18 and 24 months post-operatively. Pain intensity and quality of life outcomes were assessed using the Brief Pain Inventory (Pain Severity and Pain Interference scales) and Pain Catastrophizing Scale. Outcomes were compared between acute and non-acute TMR using the Wilcoxon ranked-sum test or Fisher's exact test as appropriate. Multilevel mixed-effects linear regression was used to account for repeat measures and potential pain confounders.

RESULTS

Thirty-two patients with 38 major limb amputations were included. Acute TMR patients reported significantly lower RLP and PLP scores, pain interference and pain catastrophisation at all time points (p < 0.05). Acute TMR was significantly associated with lower pain severity and pain interference in a linear mixed-effects model accounting for patient age, gender, amputation indication, amputation site, time post-TMR and repeated surveys (p < 0.05). There was no significant difference in the complication rate (p = 0.51).

CONCLUSION

Acute TMR was associated with clinically and statistically significant pain outcomes that were better than that in non-acute TMR. This suggests that TMR should be performed with preventative intent, when possible, as part of a multidisciplinary approach to pain management, rather than deferred until the development of chronic pain.

Optimizing Surgical Outcomes and the Role of Preventive Surgery: A Scoping Review

BACKGROUND

 Plastic and reconstructive surgeons are often presented with reconstructive challenges as a sequela of complications in high-risk surgical patients, ranging from exposure of hardware, lymphedema, and chronic pain after amputation. These complications can result in significant morbidity, recovery time, resource utilization, and cost. Given the prevalence of surgical complications managed by plastic and reconstructive surgeons, developing novel preventative techniques to mitigate surgical risk is paramount.

METHODS

 Herein, we aim to understand efforts supporting the nascent field of Preventive Surgery, including (1) enhanced risk stratification, (2) advancements in postoperative care. Through an emphasis on four surgical cohorts who may benefit from preventive surgery, two of which are at high risk of morbidity from wound-related complications (patients undergoing sternotomy and spine procedures) and two at high risk of other morbidities, including lymphedema and neuropathic pain, we aim to provide a comprehensive and improved understanding of preventive surgery. Additionally, the role of risk analysis for these procedures and the relationship between microsurgery and prophylaxis is emphasized.

RESULTS

 (1) medical optimization and prehabilitation, (2) surgical mitigation techniques.

CONCLUSION

 Reconstructive surgeons are ideally placed to lead efforts in the creation and validation of accurate risk assessment tools and to support algorithmic approaches to surgical risk mitigation. Through a paradigm shift, including universal promotion of the concept of "Preventive Surgery," major improvements in surgical outcomes may be achieved.

Prevalence of chronic pain after severe lower limb injury (SLLI): A systematic review and meta-analysis

BACKGROUND

Globally, severe lower limb injuries (SLLIs) are the predominant cause of long-term injury related disability and poor functional outcomes. Chronic pain is a major source of this morbidity, but the magnitude of the contribution is not clearly understood. The aim of this systematic review and meta-analysis was to determine the prevalence of chronic pain following SLLIs in civilian and military patients.

METHOD

This systematic review was prospectively registered with The International Prospective Register of Systematic Reviews (PROSPERO) with study ID CRD42022313615. A systematic literature search (Medline, Embase, Ovid, and Web of Science) was performed to identify original studies that reported chronic pain outcomes for adults who underwent surgical treatment for SLLIs in a civilian or military setting. Risk of bias in included studies was assessed using the ROBINS-E tool, and quality assessment was reported at study level using the Newcastle-Ottawa Scale, and at outcome-level using the GRADE framework. Absolute (proportional) and relative (odds ratio) outcome measures were calculated and pooled using a random effects model.

RESULTS

Forty-three studies reporting the outcomes of 5601 patients were included. Estimated overall prevalence of pain was 63 % (CI 55-70 %). The prevalence of chronic pain in amputees (64 % (CI 55-73 %)) was similar to those who underwent limb salvage (56 % (CI 44-67 %)). The prevalence of chronic pain in civilian populations was 70 % (CI 63-77 %) compared to military populations (51 % (CI 35-66 %)). In amputees, the prevalence of residual limb pain was similar to phantom limb pain (OR 1.06 [0.64-1.78], p = 0.81, I2 = 92 %).

CONCLUSION

Most people who sustain a SLLI will suffer from chronic pain. Healthcare systems must continue to research interventions that can reduce the incidence and severity of long-term pain and ensure adequate resources are allocated for this common and debilitating complication.

The lived experience of military beneficiaries with amputations at the hip and pelvic level

BACKGROUND

Hip- and pelvic-level amputations are devastating injuries that drastically alter patient function and quality of life. This study examined the experience of military beneficiaries with a hip- or pelvic-level amputation to better characterize their challenges and specific needs and to optimize treatment in the future.

METHODS

We conducted a retrospective review of the Military Health System and identified 118 patients with a history of one or more amputation(s) at the hip or pelvic level between October 2001 and September 2017. Surviving participants (n = 97) were mailed a letter which explained the details of the study and requested participation in a telephonic interview. A total of six individuals (one female, five males) participated in structured interviews.

RESULTS

The study group included four participants with hip disarticulations and two participants with hemipelvectomies (one internal, one external). All six participants reported significant challenges with activities related to prosthetic use, mobility, residual limb health, pain, gastrointestinal and genitourinary function, psychiatric health, and sexual function.

CONCLUSIONS

These interviews highlight the unique needs of individuals with hip- and pelvic-level amputations and may improve access to higher echelons of care that would enhance the function and quality of life for these participants.

The effect of medium-tension bandage and stump stocking on residual limb maturation in earthquake survivors

BACKGROUND

Residual limb maturation is a crucial stage in postamputation care.

OBJECTIVE

It was aimed to examine the effect of medium tension bandages and stump stockings on postamputation stump maturation in patients who underwent lower extremity amputations.

STUDY DESIGN

In this prospective observational study, patients who were earthquake survivors and had undergone emergency amputation of their lower extremities were included.

METHODS

Medium-tension elastic bandage or personalized stump stockings were used for stump maturation. Residual limb volume was measured once a week for 3 weeks.

RESULTS

The study included 23 patients and 29 amputated limbs. Because of the larger stump volume of transfemoral amputations and the higher number of these patients in the stocking group ( p < 0.001), the stump volume differed across groups before and during the follow-up ( p < 0.001). There was no difference in mean volumetric measurement between the bandage and stocking groups over time ( p = 0.272). Although the group interaction was significant (p < 0.001), the group × time interaction was not ( p = 0.306).

CONCLUSION

Medium-tension bandages and stump stockings had a similar effect on postamputation stump maturation in patients with lower extremity amputations. So, depending on the patient's and physician's preferences, both procedures can be used for stump maturation.

Opioid Use Disorder in Patients Undergoing Major Lower Extremity Amputation: Prevalence and Outcomes

INTRODUCTION

Patients with a history of Opioid Use Disorder (OUD) have higher postoperative complication rates and mortality in many settings. Yet, it remains poorly understood how the opioid epidemic has affected patients undergoing major lower extremity amputation (LEA) and whether outcomes differ by OUD status.

METHODS

We conducted a retrospective chart review of all 689 patients who underwent major LEA at a large tertiary referral center from 2015 to 2021. This study assessed patient characteristics and long-term postoperative outcomes for patients with preoperative OUD.

RESULTS

133 (19.3%) patients had a lifetime history of preoperative OUD. Preoperative OUD was associated with key characteristics, comorbidities, and outcome measures. OUD was significantly associated with younger age (P < .001), black race (P = .026), single relationship status (P < .001), BMI <30 (P = .024), no primary care provider (P = .004), and Medicaid insurance (P < .001). Comorbidities significantly associated with OUD include current smoking (P < .001), Human Immunodeficiency Virus (HIV; P = .003), and history of osteomyelitis (P < .001). Preoperative OUD independently predicted lower rates of 30-60-day readmission (odds ratio [OR] .54, P = .018) and 1-12-month reamputation (OR .41, P = .006). There was no significant difference in long-term mortality and follow-up.

CONCLUSION

This study demonstrates the prevalence of OUD in patients undergoing major LEA and reports associations and long-term outcomes. Our findings highlight the importance of recognizing OUD and raise questions about the mechanisms underlying its relation to rates of postoperative readmission and reamputation.

A systematic review of the prevalence of postamputation and chronic neuropathic pain associated with combat injury in military personnel

ABSTRACT

Combat trauma can lead to widespread tissue damage and limb loss. This may result in chronic neuropathic and post amputation pain, including phantom limb pain (PLP) and residual limb pain (RLP). The military population is distinct with respect to demographic, injury, and social characteristics compared with other amputation and trauma cohorts. We undertook a systematic review of studies of military personnel, with a history of combat injury, that reported a prevalence of any type of postamputation pain or chronic neuropathic pain, identified from Embase and MEDLINE databases.Using the inverse variance method with a random-effects model, we undertook a meta-analysis to determine an overall prevalence and performed exploratory analyses to identify the effect of the type of pain, conflict, and time since injury on prevalence. Pain definitions and types of pain measurement tools used in studies were recorded. Thirty-one studies (14,738 participants) were included. The pooled prevalence of PLP, RLP, and chronic neuropathic pain were 57% (95% CI: 46-68), 61% (95% CI: 50-71), and 26% (95% CI: 10-54), respectively. Between-study heterogeneity was high (I 2 : 94%-98%). Characterisation of duration, frequency, and impact of pain was limited. Factors reported by included studies as being associated with PLP included the presence of RLP and psychological comorbidity. The prevalence of postamputation pain and chronic neuropathic pain after combat trauma is high. We highlight inconsistency of case definitions and terminology for pain and the need for consensus in future research of traumatic injury.

Pain in the Context of Sensory Deafferentation

Pain that accompanies deafferentation is one of the most mysterious and misunderstood medical conditions. Prevalence rates for the assorted conditions vary considerably but the most reliable estimates are greater than 50% for strokes involving the somatosensory system, brachial plexus avulsions, spinal cord injury, and limb amputation, with controversy surrounding the mechanistic contributions of deafferentation to ensuing neuropathic pain syndromes. Deafferentation pain has also been described for loss of other body parts (e.g., eyes and breasts) and may contribute to between 10% and upwards of 30% of neuropathic symptoms in peripheral neuropathies. There is no pathognomonic test or sign to identify deafferentation pain, and part of the controversy surrounding it stems from the prodigious challenges in differentiating cause and effect. For example, it is unknown whether cortical reorganization causes pain or is a byproduct of pathoanatomical changes accompanying injury, including pain. Similarly, ascertaining whether deafferentation contributes to neuropathic pain, or whether concomitant injury to nerve fibers transmitting pain and touch sensation leads to a deafferentation-like phenotype can be clinically difficult, although a detailed neurologic examination, functional imaging, and psychophysical tests may provide clues. Due in part to the concurrent morbidities, the physical, psychologic, and by extension socioeconomic costs of disorders associated with deafferentation are higher than for other chronic pain conditions. Treatment is symptom-based, with evidence supporting first-line antineuropathic medications such as gabapentinoids and antidepressants. Studies examining noninvasive neuromodulation and virtual reality have yielded mixed results.

The prevalence and risk factors for phantom limb pain: a cross-sectional survey

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.

Use of virtual reality for the management of phantom limb pain: a systematic review

PURPOSE

To summarize the research on the effectiveness of virtual reality (VR) therapy for the management of phantom limb pain (PLP).

METHODS

Three databases (SCOPUS, Ovid Embase, and Ovid MEDLINE) were searched for studies investigating the use of VR therapy for the treatment of PLP. Original research articles fulfilling the following criteria were included: (i) patients 18 years and older; (ii) all etiologies of amputation; (iii) any level of amputation; (iv) use of immersive VR as a treatment modality for PLP; (v) self-reported objective measures of PLP before and after at least one VR session; (vi) written in English.

RESULTS

A total of 15 studies were included for analysis. Fourteen studies reported decreases in objective pain scores following a single VR session or a VR intervention consisting of multiple sessions. Moreover, combining VR with tactile stimulation had a larger beneficial effect on PLP compared with VR alone.

CONCLUSIONS

Based on the current literature, VR therapy has the potential to be an effective treatment modality for the management of PLP. However, the low quality of studies, heterogeneity in subject population and intervention type, and lack of data on long-term relief make it difficult to draw definitive conclusions.IMPLICATION FOR REHABILITATIONVirtual reality (VR) therapy has emerged as a new potential treatment option for phantom limb pain (PLP) that circumvents some limitations of mirror therapy.VR therapy was shown to decrease PLP following a single VR session as well as after an intervention consisting of multiple sessions.The addition of vibrotactile stimuli to VR therapy may lead to larger decreases in PLP scores compared with VR therapy alone.

Phantom Limb Pain and Painful Neuroma After Dysvascular Lower-Extremity Amputation: A Systematic Review and Meta-Analysis

BACKGROUND

Phantom limb pain (PLP) and symptomatic neuroma can be debilitating and significantly impact the quality of life of amputees. However, the prevalence of PLP and symptomatic neuromas in patients following dysvascular lower limb amputation (LLA) has not been reliably established. This systematic review and meta-analysis evaluates the prevalence and incidence of phantom limb pain and symptomatic neuroma after dysvascular LLA.

METHODS

Four databases (Embase, MEDLINE, Cochrane Central, and Web of Science) were searched on October 5th, 2022. Prospective or retrospective observational cohort studies or cross-sectional studies reporting either the prevalence or incidence of phantom limb pain and/or symptomatic neuroma following dysvascular LLA were identified. Two reviewers independently conducted the screening, data extraction, and the risk of bias assessment according to the PRISMA guidelines. To estimate the prevalence of phantom limb pain, a meta-analysis using a random effects model was performed.

RESULTS

Twelve articles were included in the quantitative analysis, including 1924 amputees. A meta-analysis demonstrated that 69% of patients after dysvascular LLA experience phantom limb pain (95% CI 53-86%). The reported pain intensity on a scale from 0-10 in LLA patients ranged between 2.3 ± 1.4 and 5.5 ± .7. A single study reported an incidence of symptomatic neuroma following dysvascular LLA of 5%.

CONCLUSIONS

This meta-analysis demonstrates the high prevalence of phantom limb pain after dysvascular LLA. Given the often prolonged and disabling nature of neuropathic pain and the difficulties managing it, more consideration needs to be given to strategies to prevent it at the time of amputation.

Modulations in high-density EEG during the suppression of phantom-limb pain with neurostimulation in upper limb amputees

Phantom limb pain (PLP) is a distressing and persistent sensation that occurs after the amputation of a limb. While medication-based treatments have limitations and adverse effects, neurostimulation is a promising alternative approach whose mechanism of action needs research, including electroencephalographic (EEG) recordings for the assessment of cortical manifestation of PLP relieving effects. Here we collected and analyzed high-density EEG data in 3 patients (P01, P02, and P03). Peripheral nerve stimulation suppressed PLP in P01 but was ineffective in P02. In contrast, transcutaneous electrical nerve stimulation was effective in P02. In P03, spinal cord stimulation was used to suppress PLP. Changes in EEG oscillatory components were analyzed using spectral analysis and Petrosian fractal dimension. With these methods, changes in EEG spatio-spectral components were found in the theta, alpha, and beta bands in all patients, with these effects being specific to each individual. The changes in the EEG patterns were found for both the periods when PLP level was stationary and the periods when PLP was gradually changing after neurostimulation was turned on or off. Overall, our findings align with the proposed roles of brain rhythms in thalamocortical dysrhythmia or disruption of cortical excitation and inhibition which has been linked to neuropathic pain. The individual differences in the observed effects could be related to the specifics of each patient's treatment and the unique spectral characteristics in each of them. These findings pave the way to the closed-loop systems for PLP management where neurostimulation parameters are adjusted based on EEG-derived markers.

Limb Amputations in Cancer: Modern Perspectives, Outcomes, and Alternatives

PURPOSE OF REVIEW

This review summarizes current findings regarding limb amputation within the context of cancer, especially in osteosarcomas and other bony malignancies. We seek to answer the question of how amputation is utilized in the contemporary management of cancer as well as explore current advances in limb-sparing techniques.

RECENT FINDINGS

The latest research on amputation has been sparse given its extensive history and application. However, new research has shown that rotationplasty, osseointegration, targeted muscle reinnervation (TMR), and regenerative peripheral nerve interfaces (RPNI) can provide patients with better functional outcomes than traditional amputation. While limb-sparing surgeries are the mainstay for managing musculoskeletal malignancies, limb amputation is useful as a palliative technique or as a primary treatment modality for more complex cancers. Currently, rotationplasty and osseointegration have been valuable limb-sparing techniques with osseointegration continuing to develop in recent years. TMR and RPNI have also been of interest in the modern management of patients requiring full or partial amputations, allowing for better control over myoelectric prostheses.

Prevalence of physical health comorbidities and long-term functional outcomes among community-reintegrated veterans following lower limb amputation in Sri Lanka

INTRODUCTION

Lower limb amputation (LLA) poses significant health challenges, including physical health comorbidities (PHCs) and functional limitations. Military veterans, who typically undergo traumatic LLA at a young age, endure these challenges for an extended period. Understanding the extent of these challenges is vital to designing tailored and feasible postamputation care for them. In this study, we evaluated the prevalence of PHCs and long-term functional outcomes among community-reintegrated veterans following LLA in Sri Lanka.

METHODS

A comparative cross-sectional study was conducted in five districts in Sri Lanka. Prevalence of PHCs and functional outcomes were compared between community-reintegrated veterans with war-related traumatic LLA and a matched able-bodied cohort. Data on PHCs were collected from participants' medical records and through a self-administered questionnaire. Timed-Up-and-Go (TUG) and 2 min walk test (2MWT) were used to compare functional outcomes between the groups. Veterans' functional level was identified using the K-level classification.

RESULTS

Veterans were active prosthetic users who had undergone LLA >10 years ago. Sixty-six (77.6%) veterans reported experiencing phantom limb pain. A significantly higher prevalence of diabetes mellitus (34.2%), hypertension (22.4%), knee osteoarthritis (18.8%), knee pain (20%) and back pain (69.4%) was observed among veterans compared with the able-bodied group (p<0.05). Veterans demonstrated significantly lower levels of functional mobility (2MWT: mean (SD): 113.6 (14.8); increased risk of falling (TUG): mean (SD): 10.6 (1.8)) compared with able-bodied individuals (150.8 (11.9) and 7.2 (0.9), respectively, p<0.001). The majority of the veterans belonged to the K3 functional level (71.8%).

CONCLUSIONS

The higher prevalence of PHCs and impaired functional outcomes underscores the multifaceted health challenges faced by veterans with LLA living in low-resource community settings with limited access to rehabilitation. These findings provide insights into the unique rehabilitation needs of individuals with similar backgrounds, informing the design and implementation of tailored rehabilitation interventions.

Risk Factors Analysis of Phantom Limb Pain in Amputees with Malignant Tumors

Purpose

Postamputation neuropathic pain is a common disease in patients with malignant tumor amputation, seriously affecting amputees' quality of life and mental health. The objective of this study was to identify independent risk factors for phantom limb pain in patients with tumor amputation and to construct a risk prediction model.

Methods

Patients who underwent amputation due to malignant tumors from 2013 to 2023 were retrospectively analyzed and divided into phantom limb pain group and non-phantom limb pain group. To determine which preoperative factors would affect the occurrence of phantom limb pain, we searched for candidate factors by univariate analysis and used multivariate logistic regression analysis to identify independent factors and construct a predictive model. The receiver operating characteristic curve (ROC) was drawn to further evaluate the accuracy of the prediction model in evaluating the phantom limb pain after amputation of bone and soft tissue tumors.

Results

Multivariate analysis showed that age (OR, 1.054; 95% CI, 1.027 to 1.080), preoperative pain (OR, 5.773; 95% CI, 2.362 to 14.104), number of surgeries (OR, 3.425; 95% CI, 1.505 to 7.795), amputation site (OR, 5.848; 95% CI, 1.837 to 18.620), amputation level (OR, 8.031; 95% CI, 2.491 to 25.888) were independent risk factors for phantom limb pain for bone and soft tissue tumors. The the area under the curve (AUC) of this model was 0.834.

Conclusion

Risk factors for postoperative phantom limb pain were the site of amputation, proximal amputation, preoperative pain, multiple amputations, and older age. These factors will help surgeons to individualize and stratify phantom limb pain and help patients with risk counseling. In particular, an informed clinical decision targeting those modifiable factors can be considered when needed.

Targeted muscle reinnervation in managing post-amputation related pain: A systematic review and meta-analysis

INTRODUCTION

Limb amputation can cause residual limb pain (RLP) and/or phantom limb pain (PLP). Although targeted muscle reinnervation (TMR) was initially introduced to facilitate the control of prosthetic limbs, it has been noted that these patients experience less pain and improved prosthetic functional outcomes. As a result, the use of TMR in managing neuroma-related RLP is increasing. The aim of this review is to assess the quality and strength of the evidence supporting the effectiveness of TMR in managing amputation-related pain.

METHODS

Five different databases, including MEDLINE (PubMed), Scopus, Web of Science, Cochrane Library, and Embase, were searched from inception to March 2022. The protocol for this systematic review has been registered in the PROSPERO database (CRD42020218242). To be included, studies needed to compare pre- and postoperative pain outcomes or different techniques for adult patients who underwent TMR following amputation. Eligible studies also needed to use patient-reported outcome measures (PROMS) and be clinical trials or observational studies published in English. Excluded studies were case reports, case series, reviews, proof of concept studies, and conference proceedings. A meta-analysis was performed on studies that had similar intervention and control groups to examine treatment effects using a random-effects model. Studies were weighted using the inverse variance method, and a statistically significant p-value was considered to be less than or equal to 0.05.

RESULTS

This review included five studies for qualitative analysis and four studies for quantitative analysis. Reviewed studies enrolled a total of 127 patients. The TMR group was compared with standard treatment at 12 months follow-up. The TMR group showed significantly better PLP as assessed by the numerical rating score RLP, and PLP assessed using Patient-Reported Outcomes Measurement Information System (PROMIS) also showed significantly lower pain intensity in the TMR group.

CONCLUSION

There is limited evidence of good quality favoring TMR in reducing postamputation PLP and RLP pain compared with standard care. Randomized clinical trials are encouraged to compare the efficacy of different surgical techniques.

The effect of rehabilitation therapies on quality of life and function in individuals with phantom limb pain after lower-limb amputation: A systematic review

PURPOSE

To evaluate the existing evidence surrounding the effect of rehabilitation therapies on quality of life (QOL) and function of individuals with a lower-limb amputation and experiencing phantom limb pain (PLP).

METHODS

This review followed Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology. Four databases were searched with key terms that covered 4 broad areas: phantom limb, lower-limb amputation, rehabilitation interventions, and randomized controlled trial (no date limits). Outcomes of either function or QOL in people receiving rehabilitation for PLP were included. The RoB2.0 risk-of-bias tool was used to rate quality.

RESULTS

Five studies were included, reporting on QOL (n = 5) and function (n = 3), using interventions including mirror therapy, phantom exercises, and muscle relaxation. The evidence was mixed in direction and significance, and this was likely attributed to by the heterogeneity of interventions and types of outcomes as well as incomplete reporting. There was very low certainty in the effect of these rehabilitation interventions to affect QOL or function.

CONCLUSION

The overall effect of rehabilitation interventions on QOL and function is inconclusive because of the variable results across the included randomized controlled trials. More research is needed to explore the impact of interventions beyond the outcome of pain and to establish a clearer conclusion. Including measures of QOL and function as well as pain in studies with people with PLP is encouraged.

Effectiveness and Equity in Community-Based Rehabilitation on Pain, Physical Function, and Quality of Life After Unilateral Lower Limb Amputation: A Systematic Review

OBJECTIVES

To synthesize evidence for (1) the effectiveness of exercise-based rehabilitation interventions in the community and/or at home after transfemoral and transtibial amputation on pain, physical function, and quality of life and (2) the extent of inequities (unfair, avoidable differences in health) in access to identified interventions.

DATA SOURCES

Embase, MEDLINE, PEDro, Cinahl, Global Health, PsycINFO, OpenGrey, and ClinicalTrials.gov were systematically searched from inception to August 12, 2021, for published, unpublished, and registered ongoing randomized controlled trials.

STUDY SELECTION

Three review authors completed screening and quality appraisal in Covidence using the Cochrane Risk of Bias Tool. Included were randomized controlled trials of exercise-based rehabilitation interventions based in the community or at home for adults with transfemoral or transtibial amputation that assessed effectiveness on pain, physical function, or quality of life.

DATA EXTRACTION

Effectiveness data were extracted to templates defined a priori and the PROGRESS-Plus framework was used for equity factors.

DATA SYNTHESIS

Eight completed trials of low to moderate quality, 2 trial protocols, and 3 registered ongoing trials (351 participants across trials) were identified. Interventions included cognitive behavioral therapy, education, and video games, combined with exercise. There was heterogeneity in the mode of exercise as well as outcome measures employed. Intervention effects on pain, physical function, and quality of life were inconsistent. Intervention intensity, time of delivery, and degree of supervision influenced reported effectiveness. Overall, 423 potential participants were inequitably excluded from identified trials (65%), limiting the generalizability of interventions to the underlying population.

CONCLUSIONS

Interventions that were tailored, supervised, of higher intensity, and not in the immediate postacute phase showed greater promise for improving specific physical function outcomes. Future trials should explore these effects further and employ more inclusive eligibility to optimize any future implementation.

Transhumeral amputation in brachial plexus lesion patients: A multicenter case series

BACKGROUND

A flail limb can be the result of a traumatic complete brachial plexus lesion. Some patients prefer retaining the flail limb, however some patients feel that a flail limb negatively affects daily life. In these circumstances an elective amputation is sometimes elected, however long-term follow-up, with respect to satisfaction and function is unknown. The aim of this study is to evaluate the long-term outcome of this rare and life changing operation.

MATERIALS AND METHODS

8 patients with a transhumeral amputation performed in 2 specialized medical centers were included. Postoperatively, the functional- and psychological outcome and the quality of life were evaluated with standardized patient reported outcome measures (PROMs; DASH, SIP-68, EQ-5D-5L and HADS).

RESULTS

After a median of 9.4 (range 7.5 - 12.8) years follow-up, 7 patients (88%) stated that they would undergo the operation again and were satisfied with the results. At latest follow-up the median DASH score was 37.3 (range 8.3-61.7), the median SIP-68 score was 6.5 (range 0-43) and the median HADS score was 3.0 (range 0-14) for anxiety and 3.0 (range 1-19) for depression. In the EQ-5D-5L patients had most difficulties in self-care, usual activities and pain/discomfort. The median overall health status was 69 (range 20-95).

DISCUSSION

With the right indication a transhumeral amputation is a reasonable option for traumatic complete brachial plexus lesion with satisfying long-term results.

LEVEL OF EVIDENCE

IV, multicenter case series.

Reorganization of sensorimotor representations of the intact limb after upper but not lower limb traumatic amputation

It is becoming increasingly clear that limb loss induces wider spread reorganization of representations of the body that are nonadjacent to the affected cortical territory. Data from upper extremity amputees reveal intrusion of the representation of the ipsilateral intact limb into the former hand territory. Here we test for the first time whether this reorganization of the intact limb into the deprived cortex is specific to the neurological organization of the upper limbs or reflects large scale adaptation that is triggered by any unilateral amputation. BOLD activity was measured as human subjects with upper limb and lower limb traumatic amputation and their controls moved the toes on each foot, open and closed each hand and pursed their lips. Subjects with amputation were asked to imagine moving the missing limb while remaining still. Bayesian pattern component modeling of fMRI data showed that intact ipsilateral movements and contralateral movements of the hand and foot were distinctly represented in the deprived sensorimotor cortex years after upper limb amputation. In contrast, there was evidence reminiscent of contralateral specificity for hand and foot movements following lower limb amputation, like that seen in controls. We propose the cortical reorganization of the intact limb to be a function of use-dependent plasticity that is more specific to the consequence of upper limb loss of forcing an asymmetric reliance on the intact hand and arm. The contribution of this reorganization to phantom pain or a heightened risk of overuse and resultant maladaptive plasticity needs investigating before targeting such reorganization in intervention.

Interplay Between Innovation and Intersubjectivity: Therapists Perceptions of Phantom Motor Execution Therapy and Its Effect on Phantom Limb Pain

Purpose

Interpersonal processes, including therapeutic alliance, may modulate the impact of interventions on pain experience. However, the role of interpersonal context on the effects of technology-enhanced interventions remains underexplored. This study elicited therapists' perspectives on how a novel rehabilitative process, involving Phantom Motor Execution (PME), may impact phantom limb pain. The mediating role of therapeutic alliance, and the way PME influenced its formation, was investigated.

Methods

A qualitative descriptive design, using a framework method, was used to explore therapists' (n=11) experiences of delivering PME treatment. Semi-structured online-based interviews were conducted.

Results

A 3-way interaction between therapist, patient, and the PME device was an overarching construct tying four themes together. It formed the context for change in phantom limb experience. The perceived therapeutic effects (theme 1) extended beyond those initially hypothesised and highlighted the mediating role of the key actors and context (theme 2). The therapeutic relationship was perceived as a transformative journey (theme 3), creating an opportunity for communication, collaboration, and bonding. It was seen as a cause and a consequence of therapeutic effects. Future directions, including the role of expertise-informed adaptations and enabling aspects of customised solutions, were indicated (theme 4).

Conclusion

This study pointed to intrapersonal, interpersonal, and contextual factors that should be considered in clinical implementation of novel rehabilitative tools. The results demonstrated that therapists have unique insights and a crucial role in facilitating PME treatment. The study highlighted the need to consider the biopsychosocial model of pain in designing, evaluating, and implementing technology-supported interventions.

Calcitonin in the Treatment of Phantom Limb Pain: A Systematic Review

INTRODUCTION

Phantom limb pain (PLP) refers to pain perceived in a part of the body removed by amputation or trauma. Despite the high prevalence of PLP following amputation and the significant morbidity associated with it, robust therapeutic approaches are currently lacking. Calcitonin, a polypeptide hormone, has recently emerged as a novel analgesic with documented benefits in the treatment of several pain-related conditions.

METHODS

We present a systematic review that comprehensively evaluates the analgesic effects of calcitonin for patients with PLP. We searched MEDLINE, OLDMEDLINE, and PubMed Central databases with the key words "calcitonin" "phantom limb pain" and "phantom pain" to identify clinical studies evaluating the efficacy or effectiveness of calcitonin administration, in any form and dose, for the treatment of PLP. Additionally, Google Scholar was searched manually with the search term "calcitonin phantom limb pain". All four databases were searched from inception until 1 December 2022. The methodological quality of each included study was assessed using the Downs and Black checklist and the GRADE criteria were used to assess effect certainty and risk of bias.

RESULTS

Our search identified 4108 citations, of which six ultimately met the criteria for inclusion in the synthesis. The included articles described a mix of open-label (n = 2), prospective observational cohort (n = 1), and randomized clinical trials (n = 3). The most common treatment regimen in the current literature is a single intravenous infusion of 200 IU salmon-derived calcitonin.

CONCLUSION

The available evidence supported the use of calcitonin as either monotherapy or adjuvant therapy in the treatment of PLP during the acute phase, while the evidence surrounding calcitonin treatment in chronic PLP is heterogeneous. Given the limited treatment options for the management of PLP and calcitonin's relatively wide therapeutic index, further research is warranted to determine the role that calcitonin may play in the treatment of PLP and other pain disorders.

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.

Detangling the Structural Neural Correlates Associated with Resting versus Dynamic Phantom Limb Pain Intensity Using a Voxel-based Morphometry Analysis

The management of phantom limb pain (PLP) is still challenging due to a partial understanding of its neurophysiological mechanisms. Structural neuroimaging features are potential biomarkers. However, only a few studies assessed their correlations with clinical severity and treatment response. This study aims to explore the association between brain gray matter volume (GMV) with phantom limb manifestations severity and PLP improvement after neuromodulatory treatments (transcranial direct current stimulation and mirror therapy). Voxel-based morphometry analyses and functional decoding using a reverse inference term-based meta-analytic approach were used. We included 24 lower limb traumatic amputees with moderate to severe PLP. We found that alterations of cortical GMV were correlated with PLP severity but not with other clinical manifestations. Less PLP severity was associated with larger brain clusters GMV in the non-affected prefrontal, insula (non-affected mid-anterior region), and bilateral thalamus. However, only the insula cluster survived adjustments. Moreover, the reverse inference meta-analytic approach revealed that the found insula cluster is highly functionally connected to the contralateral insula and premotor cortices, and the decoded psychological processes related to this cluster were "rating," "sustained attention," "impulsivity, " and "suffering." Moreover, we found that responders to neuromodulatory treatment have higher GMV in somatosensory areas (total volume of S1 and S2) in the affected hemisphere at baseline, compared to non-responders, even after adjustments.

Assessment of efficiency of mirror therapy in preventing phantom limb pain in patients undergoing below-knee amputation surgery-a randomized clinical trial

PURPOSE AND OBJECTIVES

Phantom limb pain (PLP) is a major cause of physical limitation and disability accounting for about 85% of amputated patients. Mirror therapy is used as a therapeutic modality for patients with phantom limb pain. Primary objective was to study the incidence of PLP at 6 months following below-knee amputation between the mirror therapy group and control group.

METHODS

Patients posted for below-knee amputation surgery were randomized into two groups. Patients allocated to group M received mirror therapy in post-operative period. Two sessions of therapy were given per day for 7 days and each session lasted for 20 min. Patients who developed pain from the missing portion of the amputated limb were considered to have PLP. All patients were followed up for six months and the time of occurrence of PLP and intensity of the pain were recorded among other demographic factors.

RESULTS

A total of 120 patients completed the study after recruitment. The demographic parameters were comparable between the two groups. Overall incidence of phantom limb pain was significantly higher in the control group (Group C) when compared to the mirror therapy (Group M) group [Group M = 7 (11.7%) vs Group C = 17 (28.3%); p = 0.022]. Intensity of PLP measured on the Numerical Rating Scale (NRS) was significantly lower at 3 months in Group M compared to Group C among patients who developed PLP [NRS - median (Inter quartile range): Group M 5 (4,5) vs Group C 6 (5,6); p 0.001].

CONCLUSION

Mirror therapy reduced the incidence of phantom limb pain when administered pre-emptively in patients undergoing amputation surgeries. The severity of the pain was also found to be lower at 3 months in patients who received pre-emptive mirror therapy.

TRIAL REGISTRATION

This prospective study was registered in the clinical trial registry of India.

TRIAL REGISTRATION NUMBER

CTRI/2020/07/026488.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

[Treatment and prevention phantom pain syndrome in mine-explosive injuries]

Phantom pain syndrome significantly impairs the quality of life and effectiveness of surgical treatment after limb amputations. The authors consider possible strategies for treatment and prevention in elective surgical intervention and mine-explosive injuries.

Facilitators and Barriers That Transfemoral Amputees Experience in Their Everyday Life: A Norwegian Qualitative Study

Background

Living with a lower limb amputation influences multiple facets of life due to altered function. Individuals achieve a varied level of function post amputation, depending on several variables like age, level of function prior to amputation, and available personal and environmental resources. Releasing the potential to live life to the fullest despite a disability is important to the individual.

Objectives

The primary objective of this study is to identify barriers and facilitators for function which lower limb amputees experience in their lives several years after amputation, from the amputee's perspective. This knowledge can contribute to further development of the clinical pathway for lower limb amputees in a Norwegian rehabilitation hospital.

Methods

The study has a descriptive and exploratory qualitative design with a phenomenological hermeneutical approach. Semistructured, individual interviews were conducted for data collection. Thematic analysis inspired by Braun and Clarke was used for data analysis. The sample consisted of eight transfemoral amputees (70 ± 6.9 (58-77 years)) living in the southern part of Norway. Average time since amputation was 11 years.

Results

The results have been categorised into two main themes with subthemes: (1) facilitators: personal resources, a well-fitted prosthesis, rehabilitation, social network, balance in activity/rest, and accessibility and (2) barriers: walking distance, poorly fitted prosthesis, pain, comorbidities, climate/terrain/falling, reduced local competence on amputation, and pandemic.

Conclusion

Lower limb amputees experience barriers in their everyday life, but they also develop strategies to cope with their disability. Clinical implications can include increased nutritional guidance, structural psychological mapping and follow-up, structured follow-ups over a significant period of time, and extended use of digital consultation.

[Practice of perioperative phantom limb pain prevention in Germany: a nationwide survey]

BACKGROUND

The prevalence of phantom limb pain after major amputation remains high and affected patients suffer from relevant impairments in the quality of life. Perioperative treatment strategies may prevent phantom limb pain. This study aims to assess the state of the perioperative anesthesiological pain management for major amputations. Furthermore, it analyzes potentials for optimization and barriers towards a better treatment of patients with amputations.

MATERIAL AND METHODS

This online survey was distributed by the German Society of Anesthesiology and Intensive Care Medicine (DGAI) mailing list of anesthesiological consultants. It was approved by the Charité ethics board.

RESULTS

Overall, 402 persons participated in this survey. Mostly, general anesthesia (85%), regional anesthesia (63%) and neuraxial anesthesia (49%) were performed in different combinations. Furthermore, 72% of participants reported using i.v. opioids postoperatively, mostly applied via patient-controlled analgesia (PCA). In contrast, preoperative regional anesthesia (74%) and gabapentinoids (67%) were seen as potential methods to improve treatment; however, barrier analysis revealed that treatment options are limited especially by organizational aspects and intrinsic patient factors.

CONCLUSION

This survey describes the current practice of phantom limb pain prevention in Germany. It shows an unmet need for specialized perioperative pain treatment. As the evidence regarding treatment recommendations is limited, further research questions can be deduced from this study.

An Algorithm Approach to Phantom Limb Pain

Phantom limb pain (PLP) is a common condition that occurs following both upper and lower limb amputation. First recognized and described in 1551 by Ambroise Pare, research into its underlying pathology and effective treatments remains a very active and growing field. To date, however, there is little consensus regarding the optimal management of phantom limb pain. With few large well-designed clinical trials of which to make treatment recommendations, as well as significant heterogeneity in clinical response to available treatments, the management of PLP remains challenging. Below we summarize the current state of knowledge in the field, as well as propose an algorithm for the approach to the treatment of PLP.

Factors Related to Neuropathic Pain following Lower Extremity Amputation

BACKGROUND

Lower extremity amputations are common, and postoperative neuropathic pain (phantom limb pain or symptomatic neuroma) is frequently reported. The use of active treatment of the nerve end has been shown to reduce pain but requires additional resources and should therefore be performed primarily in high-risk patients. The aim of this study was to identify the factors associated with the development of neuropathic pain following above-the-knee amputation, knee disarticulation, or below-the-knee amputation.

METHODS

Retrospectively, 1565 patients with an average follow-up of 4.3 years who underwent a primary above-the-knee amputation, knee disarticulation, or below-the-knee amputation were identified. Amputation levels for above-the-knee amputations and knee disarticulations were combined as proximal amputation level, with below-the-knee amputations being performed in 61 percent of patients. The primary outcome was neuropathic pain (i.e., phantom limb pain or symptomatic neuroma) based on medical chart review. Multivariable logistic regression was performed to identify independent factors associated with neuropathic pain.

RESULTS

Postoperative neuropathic pain was present in 584 patients (37 percent), with phantom limb pain occurring in 34 percent of patients and symptomatic neuromas occurring in 3.8 percent of patients. Proximal amputation level, normal creatinine levels, and a history of psychiatric disease were associated with neuropathic pain. Diabetes, hypothyroidism, and older age were associated with lower odds of developing neuropathic pain.

CONCLUSIONS

Neuropathic pain following lower extremity amputation is common. Factors influencing nerve regeneration, either increasing (proximal amputations and younger age) or decreasing (diabetes, hypothyroidism, and chronic kidney disease) it, play a role in the development of postamputation neuropathic pain.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Intra- and postoperative opioid-sparing analgesia in a cat undergoing pelvic limb amputation

Case summary

A combination of preoperative epidurally administered morphine, peripheral nerve blocks and postoperative wound irrigation with ropivacaine is described as an opioid-sparing analgesic protocol for a feline immunodeficiency virus-positive cat with hypertrophic cardiomyopathy undergoing hindlimb amputation. The reported strategy resulted in a lack of intraoperative sympathetic response, haemodynamic stability and adequate postoperative analgesia. No rescue analgesia was needed at any point.

Relevance and novel information

This report represents an example of how several locoregional techniques can be effectively combined to minimise the perioperative use of systemic opioids and their potential side effects in selected cases.

Making sense of phantom limb pain

Phantom limb pain (PLP) impacts the majority of individuals who undergo limb amputation. The PLP experience is highly heterogenous in its quality, intensity, frequency and severity. This heterogeneity, combined with the low prevalence of amputation in the general population, has made it difficult to accumulate reliable data on PLP. Consequently, we lack consensus on PLP mechanisms, as well as effective treatment options. However, the wealth of new PLP research, over the past decade, provides a unique opportunity to re-evaluate some of the core assumptions underlying what we know about PLP and the rationale behind PLP treatments. The goal of this review is to help generate consensus in the field on how best to research PLP, from phenomenology to treatment. We highlight conceptual and methodological challenges in studying PLP, which have hindered progress on the topic and spawned disagreement in the field, and offer potential solutions to overcome these challenges. Our hope is that a constructive evaluation of the foundational knowledge underlying PLP research practices will enable more informed decisions when testing the efficacy of existing interventions and will guide the development of the next generation of PLP treatments.

transcranial Direct Current Stimulation (tDCS) for the treatment and investigation of Phantom Limb Pain (PLP)

Phantom limb pain (PLP) is a complex medical condition that is often difficult to treat, and thus can become detrimental to patients' quality of life. No standardized clinical treatments exist and there is no conclusive understanding of the underlying mechanisms causing it. Noninvasive brain stimulation (NIBS) has been used to find correlations between changes in brain activity and various brain conditions, including neurological disease, mental illnesses, and brain disorders. Studies have also shown that NIBS can be effective in alleviating pain. Here, we examined the literature on a particular type of NIBS, known as transcranial direct current stimulation (tDCS), and its application to the treatment of PLP. We first discuss the current hypotheses on the working mechanism of tDCS and then we examine published evidence of its efficacy to treat PLP. We conclude this article by discussing how tDCS alone, and in combination with brain imaging techniques such as electroencephalography (EEG) and magnetic resonance imagining, could be applied to further investigate the mechanisms underlying PLP.

Body representation among adults with phantom limb pain: Results from a foot identification task

BACKGROUND

Impaired body representation (i.e. disrupted body awareness or perception) may be a critical, but understudied, factor underlying phantom limb pain (PLP). This cross-sectional study investigated whether adults with lower-limb loss (LLL) and PLP demonstrate impaired body representation as compared to Pain-Free peers with and without LLL.

METHODS

Participants (n = 41 adults with PLP, n = 27 Pain-Free peers with LLL, n = 39 Controls with intact limbs) completed an online foot identification task. Participants judged whether randomized images depicted left or right feet (i.e. left-right discrimination) as quickly as possible without limb movement. Using two Generalized Estimating Equations, effects of group, image characteristics (i.e. side, foot type, view, angle) and trial block (i.e. 1-4) were evaluated, with task response time and accuracy as dependent variables (a ≤ 0.050).

RESULTS

Adults with PLP demonstrated slower and less accurate performance as compared to Controls with intact limbs (p = 0.018) but performed similarly to Pain-Free peers with LLL (p = 0.394). Significant three-way interactions of group, view and angle indicated between-group differences were greatest for dorsal-view images, but smaller and angle-dependent for plantar-view images. While all groups demonstrated significant response time improvements across blocks, improvements were greatest among adults with PLP, who also reported significant reductions in pain intensity.

CONCLUSIONS

Adults with PLP demonstrate body representation impairments as compared to Controls with intact limbs. Body representation impairments, however, may not be unique to PLP, given similar performance between adults with and without PLP following LLL.

SIGNIFICANCE

Following lower-limb loss, adults with phantom limb pain (PLP) demonstrate impaired body representation as compared to Controls with intact limbs, evidenced by slower response times and reduced accuracy when completing a task requiring mental rotation. Importantly, 80% of participants with pre-task PLP reported reduced pain intensity during the task, providing compelling evidence for future investigations into whether imagery-based, mind-body interventions have positive effects on PLP.

Indications and outcomes of palliative major amputation in patients with metastatic cancer

BACKGROUND

Patients with stage IV cancer often experience diminished quality of life and pain. Although palliative amputation (PA) can reduce pain, it is infrequently performed because of the morbidity associated with amputation and the limited life expectancy in this population. Here, we describe the indications for PA in patients with stage IV carcinoma or sarcoma and discuss their clinical courses and outcomes. We hypothesized that PA would be associated with reduced pain and improved quality of life in these patients.

METHODS

We retrospectively reviewed medical records of all patients who underwent major amputation (proximal to the ankle or wrist) for metastatic sarcoma or carcinoma from January 1995 to April 2021. We excluded patients who underwent amputation for indications other than palliation. Cox proportional hazards regression analysis was used to determine factors associated with survival after PA.

RESULTS

Twenty-six patients underwent PA (11 for carcinoma, 15 for sarcoma). The most common indications for PA were pain (all patients) and fungating tumor (16 patients). PA was the initial surgery in 7 patients. Forequarter amputations were the most common procedure (6 patients). All patients reported reduced pain after PA, with the mean (±standard deviation) visual analog pain score (on a 10-point scale) decreasing from 5.7 ± 2.9 preoperatively to 0.43 ± 1.3 postoperatively (p < 0.001). The mean preoperative ECOG score was 1.9 ± 0.2 compared with 1.3 ± 0.1 postoperatively (p < 0.001). Fourteen patients were fitted for prostheses (6 upper extremity, 8 lower extremity). Two patients had local recurrence, both within 6 months after PA. The mean survival time after PA was 13 ± 12 months, and mean follow-up was 28 ± 29 months. Mean survival time after PA was not significantly different between patients with sarcoma (11 ± 11 months) versus carcinoma (15 ± 14 months) (p = 0.51). Adjuvant chemotherapy was positively associated with survival; no other factors were associated with survival.

CONCLUSIONS

PA was associated with significantly reduced pain in all patients with stage IV cancer. PA should be considered for those with intractable pain, fungating tumors, or symptoms that diminish quality of life.

LEVEL OF EVIDENCE

Level III.

Home-based transcranial direct current stimulation (tDCS) and motor imagery for phantom limb pain using statistical learning to predict treatment response: an open-label study protocol

BACKGROUND

Phantom limb pain (PLP) management has been a challenge due to its response heterogeneity and lack of treatment access. This study will evaluate the feasibility of a remotely home-based M1 anodal tDCS combined with motor imagery in phantom limb patients and assess the preliminary efficacy, safety, and predictors of response of this therapy.

METHODS

This is a pilot, single-arm, open-label trial in which we will recruit 10 subjects with phantom limb pain. The study will include 20 sessions. All participants will receive active anodal M1 tDCS combined with phantom limb motor imagery training. Our primary outcome will be the acceptability and feasibility of this combined intervention. Moreover, we will assess preliminary clinical (pain intensity) and physiological (motor inhibition tasks and heart rate variability) changes after treatment. Finally, we will implement a supervised statistical learning (SL) model to identify predictors of treatment response (to tDCS and phantom limb motor imagery) in PLP patients. We will also use data from our previous clinical trial (total observations=224 [n=112 x timepoints = 2)) for our statistical learning algorithms. The new prospective data from this open-label study will be used as an independent test dataset.

DISCUSSION

This protocol proposes to assess the feasibility of a novel, neuromodulatory combined intervention that will allow the design of larger remote clinical trials, thus increasing access to safe and effective treatments for PLP patients. Moreover, this study will allow us to identify possible predictors of pain response and PLP clinical endotypes.

Mechanical Pain Sensitivity in Postamputation Pain

OBJECTIVES

Postamputation, clinical markers of pain-related peripheral and central nervous system hypersensitivity remain understudied. This study aimed to identify whether adults with postamputation pain demonstrate greater pain sensitivity in primary (ie, amputated region) and secondary (ie, nonamputated region) sites, as compared with pain-free peers and controls with intact limbs.

METHODS

Ninety-four participants postunilateral, transtibial amputation (59 with pain, 35 pain-free) and 39 controls underwent pain-pressure threshold (PPT) testing at 10 sites. Pain-pressure thresholds were normalized to sex-specific control data using Z score conversions. Normalized primary-site and secondary-site PPTs were compared between groups using multivariate analysis of variance (P<0.050).

RESULTS

Compared with pain-free peers, adults with postamputation pain demonstrated reduced normalized PPTs across primary and secondary sites (mean difference=0.61-0.74, P=0.001 to 0.007). Compared with controls, adults with postamputation pain demonstrated reduced normalized PPTs (mean difference=0.52, P=0.026) only at primary sites.

DISCUSSION

Adults with postamputation pain demonstrate greater amputated region pain sensitivity as compared with pain-free peers or controls with intact limbs, indicating peripheral sensitization persists even after limb healing. Secondary-site pain sensitivity was similar between controls and adults with postamputation pain, suggesting central nervous system hypersensitivity may not be ubiquitous with postamputation pain. Studies are needed to investigate mechanisms underlying pain sensitivity differences between adults with and without postamputation pain.

Effects of Combined and Alone Transcranial Motor Cortex Stimulation and Mirror Therapy in Phantom Limb Pain: A Randomized Factorial Trial

Phantom limb pain (PLP) is a frequent complication in amputees, which is often refractory to treatments. We aim to assess in a factorial trial the effects of transcranial direct current stimulation (tDCS) and mirror therapy (MT) in patients with traumatic lower limb amputation; and whether the motor cortex plasticity changes drive these results. In this large randomized, blinded, 2-site, sham-controlled, 2 × 2 factorial trial, 112 participants with traumatic lower limb amputation were randomized into treatment groups. The interventions were active or covered MT for 4 weeks (20 sessions, 15 minutes each) combined with 2 weeks of either active or sham tDCS (10 sessions, 20 minutes each) applied to the contralateral primary motor cortex. The primary outcome was PLP changes on the visual analogue scale at the end of interventions (4 weeks). Motor cortex excitability and cortical mapping were assessed by transcranial magnetic stimulation (TMS). We found no interaction between tDCS and MT groups (F = 1.90, P = .13). In the adjusted models, there was a main effect of active tDCS compared to sham tDCS (beta coefficient = -0.99, P = .04) on phantom pain. The overall effect size was 1.19 (95% confidence interval: 0.90, 1.47). No changes in depression and anxiety were found. TDCS intervention was associated with increased intracortical inhibition (coefficient = 0.96, P = .02) and facilitation (coefficient = 2.03, P = .03) as well as a posterolateral shift of the center of gravity in the affected hemisphere. MT induced no motor cortex plasticity changes assessed by TMS. These findings indicate that transcranial motor cortex stimulation might be an affordable and beneficial PLP treatment modality.

Treatment Recommendations for Phantom Limb Pain in People with Amputations: An Expert Consensus Delphi Study

Background

Phantom limb pain (PLP) is common and often accompanied by serious suffering. Current systematic‐review evidence suggests that recommended treatments are no more effective than placebo for reducing PLP. Given the difficulty in conducting a meta‐analysis for nonpharmacological treatments and the weak evidence for pharmacological treatments for PLP, consensus on the first‐line management of PLP needs to be reached using alternative methods.

Objective

To reach expert consensus and make recommendations on the effective management of PLP.

Design

A three‐round Delphi design was used.

Setting

The study was conducted using e‐mail and Google survey tool as the main methods of communication and providing feedback.

Participants

The study included 27 clinicians and researchers from various health disciplines who are experts in PLP management.

Method

Data were collected using three sequential rounds of anonymous online questionnaires where experts proposed and ranked the treatments for PLP. A consensus was reached on the treatments that were endorsed by 50% or more of the experts.

Results

Thirty‐seven treatments were proposed for the management of PLP at the beginning of the study. Consensus was reached on seven treatments that were considered effective for managing PLP and on two treatments that were considered ineffective. Graded motor imagery, mirror therapy, amitriptyline, sensory discrimination training, and use of a functional prosthesis were endorsed by most experts because of the available backing scientific evidence and their reported efficacy in clinical practice. Cognitive behavioral therapy and virtual reality training were endorsed by most experts because of their reported efficacy in clinical practice despite indicating a dearth of scientific evidence to support their ranking. Citalopram and dorsal root ganglion pulsed radiofrequency were rejected owing to a lack of relevant scientific evidence.

Conclusion

The results of this study suggest that the nonpharmacological treatments endorsed in this study may have an important role in the management of PLP.

Phantom Limb Pain and Sensations in Chinese Malignant Tumor Amputees: A Retrospective Epidemiological Study

OBJECTIVE

Phantom limb pain (PLP) was a common problem in malignant tumor amputees that can cause considerable suffering. The purposes of this study were to determine the incidence and factors associated with the occurrence of post-operation PLP, stump limb pain (SLP), and phantom limb sensations (PLS) in tumor amputees within the first month after surgery. Additionally, differences in phantom phenomena between upper and lower extremities were investigated.

METHODS

In total, 162 amputees participated in this retrospective study who underwent malignant limb amputation between 2012 and 2019. Clinical characteristics were collected from medical records and reconfirmed by telephone interviews. A numerical rating scale (NRS) was used to quantitate phantom phenomena. We used analysis of variance and non-parametric statistics for categorical variables and ordinal variables separately.

RESULTS

In the first month after malignant amputation, the incidence of PLP was 54.3%, that of PLS was 65.4%, and that of SLP was 32.7%. The duration of preoperative pain and amputation level was significantly different for the incidence of acute PLP. Further subgroup analysis of amputation level showed that patients whose amputation level was below the wrist and ankle joints had a significantly reduced incidence of PLP (p<0.0083 in Bonferroni test). Binary logistics regression analysis determined that amputation level was the primary risk factor for the incidence of PLP. Factors related to the severity of postoperative PLP also included amputation level, preoperative pain, and amputation times. By comparing the differences between upper and lower limbs after amputation, we found that the incidence of PLS was higher after lower limb amputation, but there was no significant difference in the incidence of PLP and SLP. Preoperative experience of chemotherapy was not a risk factor for PLP.

CONCLUSION

Proximal amputation and long-term preoperative pain seemed to count more for PLP incidence. Further research may be required to individually determine factors associated with the occurrence and chronicity of phantom phenomena.