Complex regional pain syndrome

The Relation Between Reflex Sympathetic Dystrophy Syndrome and Trauma Severity in Patients With Distal Tibia Fracture

BACKGROUND

Reflex sympathetic dystrophy (RSD) syndrome is a multifactorial disorder with clinical features of neurogenic inflammation that causes hypersensitivity to pain or severe allodynia as well as blood flow problems, swelling, skin discoloration and maladaptive neuroplasticity due to vasomotor disorders. Patients with major trauma are prone to homeostasis leading to inflammatory response syndrome and multiple organ distress syndrome. Several studies have investigated the etiology of this condition, but the cause remains unknown. The role of associated factors such as the limb immobilization technique and genetics has been reported in the development of this complication, but, so far, there is no information regarding the effect of trauma severity on the risk of RSD occurrence.

OBJECTIVES

Given the importance of diagnosing and treating this condition, we aimed to study the effect of trauma severity on the prevalence of RSD.

PATIENTS AND METHODS

In this cross-sectional study, we examined patients with distal tibial fracture who visited Rasht Poursina hospital from 2010 to 2013. Exclusion criteria included associated fractures, underlying musculoskeletal diseases and mental and cognitive problems. To assess the severity of the initial injury in patients, the Hannover Fracture Scale 98 (HFS98) scoring checklist was used. The diagnosis of RSD was made on the basis of the IASP criterion. Demographic data, HFS98 scores, and information regarding RSD prevalence were analyzed using SPSS version 20. The Mann Whitney U nonparametric test was used for variables that were not normally distributed; the chi-square test was used to compare the qualitative variables.

RESULTS

Among the 488 patients, 292 (59.83%) were male. The mean age of the study population was 44 ± 9.82 years. During the 6-month follow-up, RSD occurred in 45 patients, of whom 28 (62.22%) were female and 17 (37.77%) were male; there was thus a significant difference in the prevalence of RSD in terms of gender (P = 0.00; chi square test). The mean HFS98 score in patients without and with RSD was 3.081 ± 4.083 and 4.080 ± 4.622, respectively, and the difference was not statistically significant (P = 0.363; Mann Whitney U test). Analyses of the eight items of HFS98 shows that local circulation in patients with RSD is significantly better than that in patients without RDS (0.683 ± 0.822 vs. 0.528 ± 0.629, respectively). Statistical analysis showed that the odds ratio for RSD for patients with HFS95 score > 0 was 1.079 (confidence interval [CI]: 0.898 - 1.333). Moreover, the odds ratio for RSD was 1.100 (CI: 795 - 1.531) in patients with an injury severity score higher than the calculated mean score in patients without RSD (> 4.083).

CONCLUSIONS

The results suggest no significant relationship between the severity of injury and risk of RSD occurrence, although the mean injury severity score was higher in patients with RSD than in those without RSD in this study population. The lower score of local circulation in patients with RSD than in those without RSD is a statistically significant finding and can be attributed to changes in the antioxidant levels at the injury site, which is one of the main mechanisms for the onset of RSD. Wound contamination was also justifiably higher in patients with RSD, although the difference was not statistically significant. In summary, the severity of injury alone cannot be a determining factor for predicting the probability of RSD.

Incidence of complex regional pain syndrome after foot and ankle surgery

Complex regional pain syndrome (CRPS) is an uncommon complication of orthopedic surgery, and few investigators have considered the incidence in foot and ankle surgery. In the present retrospective cohort study of 390 patients who had undergone elective foot and/or ankle surgery in our department from January to December 2009, the incidence of postoperative CRPS was calculated and explanatory variables were analyzed. A total of 17 patients (4.36%) were identified as meeting the International Association for the Study of Pain criteria for the diagnosis of CRPS. Of the 17 patients with CRPS, the mean age was 47.2 ± 9.7 years, and 14 (82.35%) were female. All the operations were elective, and 9 (52.94%) involved the forefoot, 3 (17.65%) the hindfoot, 3 (17.65%) the ankle, and 2 (11.76%) the midfoot. Twelve patients (70.59%) had new-onset CRPS after a primary procedure, and 5 (29.41%) had developed CRPS after multiple surgeries. Three patients (17.65%) had documented nerve damage intraoperatively and thus developed new-onset CRPS type 2. Blood test results were available for 14 patients (82.35%) at a minimum of 3 months postoperatively, and none had elevated inflammatory markers. Five of the patients (29.41%) were smokers, and 8 (47.06%) had had a pre-existing diagnosis of anxiety and/or depression. From our findings, we recommend that middle-age females and those with a history of anxiety or depression, who will undergo elective foot surgery, should be counseled regarding the risk of developing CRPS during the consent process. We recommend similar studies be undertaken in other orthopedic units, and we currently are collecting data from other orthopedic departments within Scotland.

Effect of vitamin C on prevention of complex regional pain syndrome type I in foot and ankle surgery

BACKGROUND

The public health cost impact of complex regional pain syndrome type I (CRPS I) is considerable in both emergency and scheduled orthopaedic surgery. We proposed to assess the effectiveness of vitamin C in prevention of CRPS I in foot and ankle surgery.

METHODS

We carried out a "before-after" quasi-experimental study comparing two chronologically successive groups without (Group I: July 2002-June 2003) and with (Group II: July 2003-June 2004) preventive 1g daily vitamin C treatment. All patients having surgery on the foot or ankle were enrolled, with the exception of diabetic foot cases. Several factors were analysed: sex, age, type of pathology, history of CRPS I, psychological context, tourniquet time, and cast immobilisation time.

RESULTS

420 feet (392 patients) were included in the study: 185 in Group I, 235 in Group II. CRPS I occurred in 18 cases in Group I (9.6%) and 4 cases in Group II (1.7%) (p<10(-4)), with history of CRPS I as a significantly correlated factor (relative risk=10.4). The psychological context (anxio-depressive state) showed a (sub-significant) tendency to increase the risk of CRPS I (relative risk=2.6).

CONCLUSION

Vitamin C has been shown to be effective in preventing CRPS I secondary to wrist fracture, but few data are available with respect to foot and ankle cases. The present study demonstrates the effectiveness of vitamin C in preventing CRPS I of the foot and ankle-a frequent complication in our control group (9.6%). The authors recommend preventive management by vitamin C.

Molecular mechanisms of neuropathic pain–phenotypic switch and initiation mechanisms

Many known painkillers are not always effective in the therapy of chronic neuropathic pain manifested by hyperalgesia and tactile allodynia. The mechanisms underlying neuropathic pain appear to be complicated and to differ from acute and inflammatory pain. Recent advances in pain research provide us with a clear picture for the molecular mechanisms of acute pain, and substantial information is available concerning the plasticity that occurs under conditions of neuropathic pain. The most important changes responsible for the mechanisms of neuropathic pain are found in the altered gene/protein expression in primary sensory neurons. After damage to peripheral sensory fibers, up-regulated expression of the Ca(v)alpha(2)delta-(1) channel subunit, the Na(v)1.3 sodium channel, and bradykinin (BK) B1 and capsaicin TRPV1 receptors in myelinated neurons contribute to hyperalgesia; while the down-regulation of the Na(v)1.8 sodium channel, B2 receptor, substance P (SP), and even mu-opioid receptors in unmyelinated neurons is responsible for the phenotypic switch in pain transmission. Clarification of the molecular mechanisms for such complicated plasticity would be extremely valuable when considering the therapeutic design of pain relieving drugs. Although many reports deal with the changes in expression of key molecules related to neuropathic pain, the initiation and the mechanisms that follow remain to be determined. The current study using lysophosphatidic acid (LPA) receptor knockout mice revealed that LPA produced by nerve injury initiates neuropathic pain and demyelination following partial sciatic nerve ligation (PSNL). A single injection of LPA was found to mimic PSNL in terms of neuropathic pain and its underlying mechanisms. This discovery may lead to the subsequent discovery of LPA-induced secondary genes, which would be therapeutic targets for neuropathic pain.

Characteristic trends of lower-extremity complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a multifaceted, progressive, and potentially devastating disorder generally affecting the extremities. In addition, scant information is available regarding the types of patients who develop lower-extremity CRPS. This is a retrospective chart review study of 64 patients who presented to a pain clinic with CRPS of the lower extremity. The study examined 23 variables broadly classified under demographic characteristics, CRPS characteristics, and healthcare utilization. The sample was found to consist of predominantly white, middle-aged women with CRPS I. Subjective complaints consisted of burning, sharp, throbbing, or aching pain with shooting symptoms. Initial presenting clinical findings included allodynia, edema, erythema, and hyperesthesia. The most common precipitating injuries were blunt trauma of the foot with or without fracture or ankle sprain. The most common inciting surgical events were bunionectomy, tarsal tunnel release, and heel-spur surgery. Referral to the pain clinic was delayed more commonly in trauma patients than in postsurgical patients, with a corresponding increase in pain clinic visits for treatment. This study may act as a guide for physicians treating the lower extremity to aid in the recognition of lower extremity complex regional pain syndrome and its characteristics.

Inpatient management of lower extremity amputations

The in-hospital care of the amputee is crucial; careful preoperative, intraoperative, and postoperative regimens set the stage for a successful clinical outcome. Caring for the patient undergoing amputation is much more than choosing the correct level at which to cut. Early aggressive rehabilitation; careful attention to postoperative complications; and appropriate physical therapy, occupational therapy, and counseling all play pivotal roles. Thorough knowledge of these issues helps to increase the likelihood of a successful outcome and to keep morbidity to a minimum.

Complex regional pain syndrome of the lower extremity: a retrospective study of 33 patients

Even when diagnosed early and treated appropriately, patients with complex regional pain syndrome (CRPS), a condition that can lead to severe painful dysfunction of the limb, may continue to have long-term pain. A retrospective study was conducted of 33 patients with a positive history of CRPS I, CRPS II, or sympathetically maintained pain (SMP) of the lower limb who were treated in either a clinical setting or a pain management center. The average age of individuals diagnosed with CRPS was 43.5 +/- 12.6 (mean +/-SD) years with 60% being female. The most common diagnosis was CRPS I (75.8%) followed by SMP (21.2%), and finally CRPS II (3.0%). The dominant etiology was confirmed as trauma (73%), with the remaining nine cases resulting from elective foot surgery. Fractures were the most common type of injury (45%) and excision of neuroma was the most frequent elective surgical procedure (30%). Time from injury to diagnosis in patients with foot and ankle trauma was 3.9 +/- 3.0 months and from elective surgery to diagnosis was 9.1 +/- 4.0 months (t test, p < .001). Thirteen patients were contacted for long-term follow-up with an average of 3.5 years after initial diagnosis. There was no difference when the pain rating at long-term follow-up was compared to the initial rating (6.2 +/- 1.2 vs. 7.3 +/- 0.6; p = .287), and 11 continue to have more than moderate pain. Thus, many patients with CRPS who seem to be successfully treated, and are discharged from care, still have severe pain years later.