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.

Examining patient reported outcome measures for phantom limb pain: measurement use in a sample of Veterans with amputation

PURPOSE

Phantom limb pain (PLP) is treated with medications and non-drug treatments. Best clinical practices for measuring treatment outcomes have not been defined. The objective of this study was to evaluate the internal consistency of patient-reported outcomes measures (PROMs) in a sample of Veterans with lower limb amputation.

MATERIALS AND METHODS

The Veteran phone survey included administering PROMs [1) PLP numeric rating scale (NRS), 2) general pain NRS, 3) Pain, Enjoyment, and General Activity (PEG) scale, 4) Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference Short Form 6b Replacement, 5) PROMIS Short Form Depression 4a and 6) PROMIS Short Form Anxiety 4a].

RESULTS

Fifty Veterans (48 male, 2 female; average age: 66 years) completed PROMs. In our sample, 40 Veterans (80%) experienced PLP with an average PLP NRS of 5 (±3.4). Internal consistency of each measure was good to excellent based on Cronbach's alpha co-efficient of >0.80. Correlations were moderate between PLP NRS and all other measures (≤0.32). Although many Veterans expressed bothersome PLP, the scores reflecting pain interference and impact on function were lower than pain intensity. Consistent use of outcome measures is needed to determine the effect of interventions for amputation-related pain.

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.

Prevalence of residual limb pain and symptomatic neuromas after lower extremity amputation: a systematic review and meta-analysis

ABSTRACT

Residual limb pain (RLP) is associated with (partial) extremity amputations and is defined as pain felt in the remaining part of the amputated limb. A common cause of RLP is neuroma formation after nerve transections. Neuromas can be very painful and severely debilitating pathologies, preventing prosthetic use, reducing quality of life, and requiring medication. Residual limb pain and symptomatic neuromas are often not properly recognized by physicians explaining the varying prevalence in the literature. This systematic review and meta-analysis aim to provide a comprehensive overview of published literature on the prevalence of RLP and symptomatic neuroma after lower extremity amputation. Studies reporting the prevalence of RLP and symptomatic neuroma pain in patients who have had a lower extremity amputation published between 2000 and 2020 were identified in PubMed and Embase. Random-effects meta-analyses of proportions were performed to quantify the prevalence of RLP and symptomatic neuroma. Subgroups were identified and analysed. For RLP, the pooled prevalence was 59% (95% CI: 51-67). For symptomatic neuromas, the pooled prevalence was 15% (95% CI: 7-28). Residual limb pain subgroup analysis showed statistically significant higher prevalence in patients aged >50 years, follow-up >2 years, and in studies using a self-administered questionnaire for data collection. The prevalence of RLP and symptomatic neuroma in patients who have had a lower extremity amputation is 59% and 15%, respectively. Knowledge of their high prevalence may result in better awareness among physicians, in turn providing timely and adequate management.

A Biomimetic Adapter for Passive Self-alignment of Prosthetic Feet

INTRODUCTION

Dynamic alignment of lower limb prostheses is subjective and time-consuming. Compensatory gait strategies caused by prosthesis misalignment can negatively affect lower limb amputees who cannot access a certified prosthetist for alignment adjustments. The objective of this study is to evaluate a novel six-degrees-of-freedom passive transtibial prosthetic adapter that self-aligns during various phases of gait. This self-aligning adapter may benefit service members and veterans stationed or living far from a clinical facility.

METHODS

Four transtibial amputee subjects, aged 47 to 62 (mean: 55.75) years with mean weight of 163.6 lbs and mean K-level of 3.25, walked at self-selected speeds on a 10-m level walkway. Subjects walked with the self-aligning and a size- or weight-matched control adapter, assembled to a commercially available energy-storing-and-returning foot and their own socket, with 22-mm alignment perturbations in the anterior, posterior, medial, or lateral directions. Subjects were blinded to both adapter type and misalignment. Socket moments, spatiotemporal gait parameters, and subjective socket comfort were recorded.

RESULTS

Preliminary results showed improvements in mean peak socket moments and step length differential with the self-aligning adapter across all alignments. Walking speed and prosthesis-side base of support showed little change in all configurations. Prosthesis-side stance duration and Functional Ambulation Profile Score increased with the self-aligning adapter in some alignments. Patient-reported socket comfort increased slightly with the self-aligning adapter across all misalignments.

CONCLUSION

Subjects maintained similar walking speeds and experienced greater gait symmetry and reduced sagittal plane peak moments with the self-aligning adapter when exposed to misalignments. These trends suggest a benefit to transtibial amputees from a reduction in secondary gait effects from prosthesis misalignments. Additionally, a wider range of acceptable prosthesis alignments may be possible with the self-aligning adapter. Subsequent trials are underway to evaluate the self-aligning adapter in real-world environments like walking on uneven terrains, stairs, ramps, and abrupt turns.

Clinical updates on phantom limb pain

Phantom limb pain is highly prevalent after amputation. Treatment results will probably benefit from an interdisciplinary team and individually adapted surgical, prosthetic and pain medicine approaches.

Introduction:

Most patients with amputation (up to 80%) suffer from phantom limb pain postsurgery. These are often multimorbid patients who also have multiple risk factors for the development of chronic pain from a pain medicine perspective. Surgical removal of the body part and sectioning of peripheral nerves result in a lack of afferent feedback, followed by neuroplastic changes in the sensorimotor cortex. The experience of severe pain, peripheral, spinal, and cortical sensitization mechanisms, and changes in the body scheme contribute to chronic phantom limb pain. Psychosocial factors may also affect the course and the severity of the pain. Modern amputation medicine is an interdisciplinary responsibility.

Methods:

This review aims to provide an interdisciplinary overview of recent evidence-based and clinical knowledge.

Results:

The scientific evidence for best practice is weak and contrasted by various clinical reports describing the polypragmatic use of drugs and interventional techniques. Approaches to restore the body scheme and integration of sensorimotor input are of importance. Modern techniques, including apps and virtual reality, offer an exciting supplement to already established approaches based on mirror therapy. Targeted prosthesis care helps to obtain or restore limb function and at the same time plays an important role reshaping the body scheme.

Discussion:

Consequent prevention and treatment of severe postoperative pain and early integration of pharmacological and nonpharmacological interventions are required to reduce severe phantom limb pain. To obtain or restore body function, foresighted surgical planning and technique as well as an appropriate interdisciplinary management is needed.

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.

More than half of persons with lower limb amputation suffer from chronic back pain or residual limb pain: a systematic review with meta-analysis

Purpose: The aim of this study is to systematically review and critically assess the methodological quality of literature regarding prevalence, characteristics and factors influencing pain, other than phantom limb pain (PLP) in persons with lower limb amputation (LLA).Materials and methods: A systematic review was performed (PROSPERO CRD42019138018). Literature was searched using PubMed, EMBASE, PsycINFO, and PEDro. Studies were included if describing pain other than PLP at least three months after amputation. For residual limb pain (RLP) and back pain, a meta-regression was performed.Results: Fifty-one studies were included in which predominantly young males with a unilateral traumatic amputation using a prosthesis were investigated. Pooled prevalence of RLP was 0.51 (95% CI 0.40-0.62) with a positive association with presence of back pain (p = 0.044) in the univariate meta-regression. Pooled prevalence of back pain was 0.55 (95% CI 0.45-0.64), with a positive association of time since amputation (p < 0.001) and co-occurrence of RLP (p = 0.050).Conclusions: Back pain and RLP are common after LLA. The prevalence of back pain was positively associated with the presence of RLP, and vice versa. Future studies should give more attention to other chronic pain types, to persons with a diabetic or vascular cause of amputation, and to pain-related interference.Implications for RehabilitationBoth back pain and residual limb pain occur in more than 50% of persons with lower limb amputation (LLA), and both pain types are positively associated.Clinicians should be aware that chronic pain is common after LLA and can have a significant impact on the functioning of persons with LLA.Future research on this topic should give more attention to other chronic pain types, to persons with a diabetic or vascular cause of amputation, and to pain-related interference.