Functional dystonia in the foot and ankle.

AIMS: To assess the characteristic clinical features, management, and outcome of patients who present to orthopaedic surgeons with functional dystonia affecting the foot and ankle. METHODS: We carried out a retrospective search of our records from 2000 to 2019 of patients seen in our adult tertiary referral foot and ankle unit with a diagnosis of functional dystonia. RESULTS: A total of 29 patients were seen. A majority were female (n = 25) and the mean age of onset of symptoms was 35.3 years (13 to 71). The mean delay between onset and diagnosis was 7.1 years (0.5 to 25.0). Onset was acute in 25 patients and insidious in four. Of the 29 patients, 26 had a fixed dystonia and three had a spasmodic dystonia. Pain was a major symptom in all patients, with a coexisting diagnosis of chronic regional pain syndrome (CRPS) made in nine patients. Of 20 patients treated with Botox, only one had a good response. None of the 12 patients who underwent a surgical intervention at our unit or elsewhere reported a subjective overall improvement. After a mean follow-up of 3.2 years (1 to 12), four patients had improved, 17 had remained the same, and eight reported a deterioration in their condition. CONCLUSION: Patients with functional dystonia typically presented with a rapid onset of fixed deformity after a minor injury/event and pain out of proportion to the deformity. Referral to a neurologist to rule out neurological pathology is advocated, and further management should be carried out in a movement disorder clinic. Response to treatment (including Botulinum toxin (Botox) injections) is generally poor. Surgery in this group of patients is not recommended and may worsen the condition. The overall prognosis remains poor. Cite this article: Bone Joint J 2021;103-B(6):1127-1132.

Local and Systemic Expression Pattern of MMP-2 and MMP-9 in Complex Regional Pain Syndrome.

Matrix metalloproteinases (MMP)-2 and MMP-9 play important roles in inflammation as well as in pain processes. For this reason, we compared the concentrations of these enzymes in skin and serum of patients with complex regional pain syndrome (CRPS), other pain diseases and healthy subjects. We analyzed ipsi- and contralateral skin biopsies of 18 CRPS patients, as well as in 10 pain controls and 9 healthy subjects. Serum samples were analyzed from 20 CRPS, 17 pain controls and 17 healthy subjects. All samples were analyzed with ELISA. Concentrations were then compared to clinical data as well as to quantitative sensory testing data.MMP-2 was increased in both ipsi- and contralateral skin biopsies of CRPS patients compared to healthy subjects. While low ipsilateral MMP-2 was associated with trophic changes, contralateral MMP-2 inversely correlated with the CRPS severity. MMP-9 was also locally increased in ipsilateral CRPS skin, and higher ipsi- and contralateral MMP-9 levels correlated with CRPS severity. We conclude that MMP-2 and MMP-9 are differently expressed depending on the clinical phenotype in CRPS. PERSPECTIVE: This article describes an upregulation of MMPs in CRPS and pain controls and shows different expression of MMP-2 and -9 depending on clinical phenotype in CRPS. These results provide evidence that MMP-2 and -9 play a key role in CRPS pathophysiology.

Dimethyl Fumarate Reduces Oxidative Stress and Pronociceptive Immune Responses in a Murine Model of Complex Regional Pain Syndrome.

BACKGROUND: Complex regional pain syndrome (CRPS) is a highly disabling cause of pain often precipitated by surgery or trauma to a limb. Both innate and adaptive immunological changes contribute to this syndrome. Dimethyl fumarate (DMF) works through the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor and other targets to activate antioxidant systems and to suppress immune system activation. We hypothesized that DMF would reduce nociceptive, functional, and immunological changes measured in a model of CRPS. METHODS: Male C57BL/6 mice were used in the well-characterized tibial fracture model of CRPS. Some groups of mice received DMF 25 mg/kg/d orally, per os for 3 weeks after fracture versus vehicle alone. Homozygous Nrf2 null mutant mice were used as test subjects to address the need for this transcription factor for DMF activity. Allodynia was assessed using von Frey filaments and hindlimb weight-bearing data were collected. The markers of oxidative stress malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) were quantified in the skin of the fractured mice using immunoassays along with the innate immune system cytokines IL-1ß and IL-6. The accumulation of IgM in the fractured limbs and lymph node hypertrophy were used as indexes of adaptive immune system activation, and the passive transfer of serum from wildtype fractured mice to B cell-deficient fractured muMT mice (mice lacking B cells and immunoglobulin) helped to assess the pronociceptive activity of humoral factors. RESULTS: We observed that oral DMF administration strongly prevented nociceptive sensitization and reduced uneven hindlimb weight bearing after fracture. DMF was also very effective in reducing the accumulation of markers of oxidative stress, activation of innate immune mediator production, lymph node hypertrophy, and the accumulation of IgM in fractured limbs. The sera of fractured vehicle-treated but not DMF-treated mice conferred pronociceptive activity to recipient mice. Unexpectedly, the effects of DMF were largely unchanged in the Nrf2 null mutant mice. CONCLUSIONS: Oxidative stress and immune system activation are robust after hindlimb fracture in mice. DMF strongly reduces activation of those systems, and the Nrf2 transcription factor is not required. DMF or drugs working through similar mechanisms might provide effective therapy for CRPS or other conditions where oxidative stress causes immune system activation.

The spectrum of pediatric amplified musculoskeletal pain syndrome.

BACKGROUND: Children presenting with musculoskeletal pain to pediatric rheumatology clinics are very heterogeneous and on a continuum from those with localized pain to total body pain. Many report intermittent, rather than constant, pain. We examined clinical and psychological characteristics of these children at presentation and specifically those who fulfilled the criteria for fibromyalgia. METHODS: We performed a retrospective, cross-sectional cohort study of children under ≤18 years old presenting to the pediatric rheumatology pain clinic between January 2015 and July 2019 and enrolled in a patient registry. We included children diagnosed with amplified pain, excluding those fulfilling criteria for complex regional pain syndrome. Abstracted data included clinical characteristics, pain symptoms, functional disability inventory (FDI), widespread pain index, and symptom severity scale. RESULTS: We analyzed 636 subjects, predominantly non-Hispanic Caucasian females. Using median split method, 54% had diffuse pain (≥ 5 body regions involved), but, of these, only 58% met criteria for fibromyalgia. Subjects with diffuse pain, compared to those with localized pain had a longer duration of pain (24 vs 12 months, p < 0.01), reported greater pain intensity (6/10 vs 5/10, p < 0.001), greater mental health burden, and poorer function (FDI 25 vs 19, p < 0.0001). Subjects with limited pain more often reported a history of trigger event (34% vs 24%, p < 0.01) but not autonomic changes (14% vs 14%, p = 0.94). The presence of adverse childhood experiences did not differ among those with limited versus diffuse pain except for parental divorce (16% vs 23%, p = 0.03). Intermittent pain was reported in 117 children (18%) and, compared to subjects with constant pain, they reported less pain (0/10 vs 6/10) and were more functional (FDI 13 vs 25) (both p < 0.0001). CONCLUSIONS: There exists a wide spectrum of pain manifestations among children with amplified pain including limited or diffuse and constant or intermittent pain. Most children who presented to our clinic did not fulfill criteria for fibromyalgia but nonetheless had significant symptoms and disability. Studies focusing on fibromyalgia may miss the full extent of childhood amplified pain. Additionally, research limited to those meeting the fibromyalgia criteria likely underestimate the significant impact of amplified pain among the pediatric population.

Complex regional pain syndrome: A case report and review of the literature.

Background: Complex regional pain syndrome (CRPS) is a rare neuropathic pain disorder associated with severe pain, muscle weakness, limb edema and hyperhidrosis. Predisposing factors include fracture, surgery, stroke and spinal cord injury. CRPS may recur in the same limb or spread to other limbs to complicate management. Case Report: A 20-year old female with CRPS Type-I had sequential spread to all four limbs despite different treatment modalities, including medical therapy, nerve block, radiofrequency ablation and surgical sympathectomy. We discuss the therapeutic challenges and reviewed recent literature on current treatment options for CRPS Type-I. Conclusion: A multidisciplinary approach is needed for effective management of CRPS, and refractory disease may respond to intrathecal baclofen with morphine.

RésuméContexte: Le syndrome douloureux régional complexe (SDRC) est un trouble neuropathique rare associé à une douleur intense, une faiblesse musculaire, un dème des membres et une hyperhidrose. Les facteurs prédisposants comprennent la fracture, la chirurgie, l'AVC et les lésions de la moelle épinière. Le SDRC peut se reproduire dans le même membre ou se propager à d'autres membres pour compliquer la gestion. Rapport de cas: une femme de 20 ans atteinte du SDRC de type I s'est propagée séquentiellement aux quatre membres malgré différentes modalités de traitement, y compris une thérapie médicale, un bloc nerveux, une ablation par radiofréquence et une sympathectomie chirurgicale. Nous discutons des défis thérapeutiques et avons passé en revue la littérature récente sur les options de traitement actuelles pour le SDRC de type I. Conclusion: Une approche multidisciplinaire est nécessaire pour une gestion efficace du SDRC, et la maladie réfractaire peut répondre au baclofène intrathécal avec de la morphine.

Comparative Study of Chronic Postischemic Pain Models in Mice: O-Ring Versus Tie Method.

BACKGROUND: The success rate for the production of animal models of chronic postischemia pain (CPIP) using an O-ring has yet to be improved in the study of complex regional pain syndrome-type I (CRPS-I), and producing a CPIP model is challenging, especially for mice. OBJECTIVES: We devised a new CPIP model with a higher success rate that induces ischemia for 3 hours by tying the hind limbs of mice with a rubber band, followed by reperfusion. STUDY DESIGN: A randomized, controlled animal trial. METHODS: Twenty-two male C57BL/6 mice were divided into a sham (n = 6), a ring (n = 8), and a tie group (n = 8). Anesthesia was induced using isoflurane. A precut O-ring was mounted on the upper left ankle in the sham group. A tight-fitting O-ring and a push-pull gauge manometer were mounted at the same location in the ring and tie groups, respectively. Reperfusion was induced 3 hours later. The thickness and circumference of the hind paws were measured before ischemia induction. Measurements were repeated 10 days after reperfusion. Mechanical allodynia was measured with a von Frey filament until 12 weeks after reperfusion. RESULTS: The new tie model required 5 additional days until the onset of allodynia compared with the existing CPIP O-ring model. However, the successful induction rate of CPIP was higher in the tie group than in the ring group, and allodynia was maintained for over 30 days in the tie group. The ring and tie groups exhibited significantly high levels of tumor necrosis factor-alpha than those in the sham group. LIMITATIONS: First, we did not evaluate hyperalgesia, cold or heat allodynia. Second, we did not measure blood levels of inflammatory or antiinflammatory cytokines, and research on oxidative stress biomarkers such as isoprostane, 8-hydroxy-2'-deoxyguanosine (a marker of DNA oxidative damage), and malondialdehyde was not performed. CONCLUSIONS: The new CPIP tie model has a higher rate of successful induction than existing O-ring models for mice, with longer duration of mechanical allodynia. The model may reduce the number of animals sacrificed in CRPS-I research and could be useful for studying long-term effects of drugs. KEY WORDS: CPIP, mouse, O-ring, rubber band, reperfusion, allodynia, hyperalgesia.

Sensory Function and Pain Experience in Arthritis, Complex Regional Pain Syndrome, Fibromyalgia Syndrome, and Pain-Free Volunteers: A Cross-Sectional Study.

OBJECTIVES: This study aimed to identify relationships between sensory function and pain in 3 common pain conditions (arthritis, Complex Regional Pain Syndrome [CRPS] and fibromyalgia syndrome [FMS]) and pain-free participants. Sensory abnormalities are known to be concomitant with some types of chronic pain but comparison across pain conditions using existing research is difficult due to methodological differences. Pragmatic Quantitative Sensory Testing (QST) methods were used. MATERIALS AND METHODS: Hot and cold sensitivity, light touch threshold (LTT), two-point discrimination and pain threshold were assessed in 143 participants (n=37 pain-free, n=34 arthritis, n=36 CRPS, n=36 FMS). Outcomes were assessed in the index ("affected" or right) and contralateral arm. Participants also completed the Brief Pain Inventory and the McGill Pain Questionnaire. RESULTS: There were statistically significant differences between groups for all QST outcomes except two-point discrimination. Relative to pain-free participants, FMS displayed heat hyperesthesia in both arms and cold hyperesthesia in the contralateral arm. CRPS demonstrated no changes in thermal sensitivity. Both CRPS and FMS exhibited bilateral pressure hyperalgesia. LTT hypoesthesia was observed bilaterally for CRPS but only in the contralateral arm for FMS. CRPS and FMS had pressure hyperalgesia in the index arm relative to arthritis patients. There were no differences between arthritis and pain-free participants for any QST outcome. In CRPS, there were significant correlations between LTT and pain outcomes bilaterally. DISCUSSION: People with FMS and CRPS demonstrate extensive sensory dysfunction. Arthritis patients had sensory profiles closer to pain-free participants. LTT may provide a clinically relevant and accessible assessment for CRPS.

Parallels between lumbosacral radiculopathy and complex regional pain syndrome: α1-adrenoceptor upregulation, reduced dermal nerve fibre density, and hemisensory disturbances in postsurgical sciatica.

Residual lower-limb pain after low back surgery (postsurgical sciatica) and complex regional pain syndrome (CRPS) involving a lower limb are separate conditions but may share some mechanisms (eg, tissue inflammation, neuroimmune disturbances, and central neuroplasticity). As adrenergically evoked pain contributes, in part, to CRPS, whether an adrenergic mechanism also contributes to postsurgical sciatica was investigated in this study. Immunohistochemistry was used to identify α1-adrenoceptors (α1-AR) on nerve fibres and other targets in the affected and contralateral skin of 25 patients with postsurgical sciatica, and α1-AR expression was investigated in relation to pain and pinprick hyperalgesia after intradermal injection of the α1-AR agonist phenylephrine. In addition, quantitative sensory testing was performed on all 4 limbs and on each side of the forehead. α1-AR expression was greater in keratinocytes (but not blood vessels or nerve fibres) in the symptomatic than contralateral leg, and dermal nerve fibre density was reduced in both legs. However, distal adrenergic involvement in pain in postsurgical sciatica seems unlikely, as neither heightened α1-AR expression in keratinocytes nor reduced dermal nerve fibre density were associated with pain or hyperalgesia to intradermal phenylephrine injection. Sensitivity to pressure-pain, pinprick, and cold-pain was greater in the ipsilateral than contralateral forehead of the entire cohort, but sensory disturbances were most pronounced in patients with additional CRPS-like features. Together, these findings suggest that bilateral distal neuropathy and central neuroplastic changes are involved not only in the pathophysiology of CRPS but also in postsurgical sciatica. This may have treatment implications for patients with postsurgical sciatica.

Chronic pain syndromes: overlapping phenotypes with common mechanisms.

The common chronic pain syndromes of fibromyalgia, regional pain syndrome, and complex regional pain syndrome have been made to appear separate because they have been historically described by different groups and with different criteria, but they are really phenotypically accented expressions of the same processes triggered by emotional distress and filtered or modified by genetics, psychology, and local physical factors.

Comparison of complex regional pain syndrome and fibromyalgia: Differences in beta and gamma bands on quantitative electroencephalography.

Complex regional pain syndrome (CRPS) and fibromyalgia (FM) share many features. Both can cause severe pain and are considered to have a mechanism of action, including dysfunction of the sympathetic nervous system. However, they have clinical differences in pain range and degree. The present study aimed to find neurophysiologic differences between CRPS and FM using quantitative electroencephalography (QEEG). Thirty-eight patients with CRPS and 33 patients with FM were included in the analysis. Resting-state QEEG data were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers. As a result, the CRPS group relative to FM group showed lower total absolute powers in the beta band (F = 5.159, P < .05), high beta (F = 14.120, P < .05), and gamma band (F = 15.034, P < .05). There were no significant differences between 2 groups in the delta, theta, and alpha bands. The present findings show that the CRPS and FM groups differ mainly in the high frequency, which may reflect their distinct pathophysiology and symptomatology. Our study suggests that the QEEG differences can be clinically useful in assessing brain function in patients with CRPS and FM.

Sensory disturbances induced by sensorimotor conflicts are higher in complex regional pain syndrome and fibromyalgia compared to arthritis and healthy people, and positively relate to pain intensity.

BACKGROUND: Sensorimotor conflicts are well known to induce sensory disturbances. However, explanations as to why patients with chronic pain are more sensitive to sensorimotor conflicts remain elusive. The main objectives of this study were (a) to assess and compare the sensory disturbances induced by sensorimotor conflict in complex regional pain syndrome (n = 38), fibromyalgia (n = 36), arthritis (n = 34) as well as in healthy volunteers (HV) (n = 32); (b) to assess whether these disturbances were related to the intensity and duration of pain, or to other clinical variables assessed using questionnaires (abnormalities in sensory perception, depression and anxiety); and (c) to categorize different subgroups of conflict-induced sensory disturbances. METHODS: One hundred and forty participants performed in phase or anti-phase movements with their arms while viewing a reflection of one arm in a mirror (and the other arm obscured). They were asked to report changes in sensory disturbances using a questionnaire. RESULTS: First, results showed that patients with complex regional pain syndrome and fibromyalgia were more prone to report sensory disturbances than arthritis patients and HV in response to conflicts (small effect size). Second, conflict-induced sensory disturbances were correlated with pain intensity (large effect size) and abnormalities in sensory perception (only in the CRPS group) but were not related to the duration of the disease or psychological factors. Finally, we identified two distinct subgroups of conflict-induced sensory disturbances. CONCLUSIONS: Our results suggest that pain lowers the threshold for the detection of sensorimotor conflicts, a phenomenon that could contribute to the maintenance of pain in clinical populations. SIGNIFICANCE: Individuals with complex regional pain syndrome and fibromyalgia were more sensitive to sensorimotor conflicts than arthritis patients and controls. Moreover, conflict-induced sensory disturbances were specific to higher pain intensity and higher sensory abnormalities in all groups, suggesting that pain lowers the threshold for the detection of sensorimotor conflicts.

Autoinflammatory and autoimmune contributions to complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is a highly enigmatic syndrome typically developing after injury or surgery to a limb. Severe pain and disability are common among those with chronic forms of this condition. Accumulating evidence suggests that CRPS may involve both autoinflammatory and autoimmune components. In this review article, evidence for dysfunction of both the innate and adaptive immune systems in CRPS is presented. Findings from human studies in which cytokines and other inflammatory mediators were measured in the skin of affected limbs are discussed. Additional results from studies of mediator levels in animal models are evaluated in this context. Similarly, the evidence from human, animal, and translational studies of the production of autoantibodies and the potential targets of those antibodies is reviewed. Compelling evidence of autoinflammation in skin and muscle of the affected limb has been collected from CRPS patients and laboratory animals. Cytokines including IL-1ß, IL-6, TNFα, and others are reliably identified during the acute phases of the syndrome. More recently, autoimmune contributions have been suggested by the discovery of self-directed pain-promoting IgG and IgM antibodies in CRPS patients and model animals. Both the autoimmune and the autoinflammatory components of CRPS appear to be regulated by neuropeptide-containing peripheral nerve fibers and the sympathetic nervous system. While CRPS displays a complex neuroimmunological pathogenesis, therapeutic interventions could be designed targeting autoinflammation, autoimmunity, or the neural support for these phenomena.

Oxidative Stress Contributes to Fracture/Cast-Induced Inflammation and Pain in a Rat Model of Complex Regional Pain Syndrome.

Clinical evidence suggests that vitamin C (Vit C) may protect against the development of complex regional pain syndrome (CRPS) after fracture or surgery. Tibia fracture followed by 4 weeks of cast immobilization (fracture/cast) in rats results in nociceptive, vascular, and bone changes resembling clinical CRPS. In this study, fracture/cast rats were treated with the oxidative stress inhibitors Vit C, N-acetyl cysteine, or 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl to examine their effects on CRPS-related nociceptive and vascular changes. Administration of these agents significantly reduced fracture/cast-induced cutaneous allodynia by 64 to 78%, muscle hyperalgesia by 34 to 40%, and hind limb unweighting by 48 to 89%. Treatments with Vit C and N-acetyl cysteine reduced the oxidative stress markers malondialdehyde in the skin, muscle, and sciatic nerve, and lactate in the gastrocnemius muscle of the fracture/cast limb. Furthermore, Vit C treatment inhibited the post-fracture upregulation of substance P and calcitonin gene-related peptide in the sciatic nerve and the increased expression of the pain-related inflammatory mediators, including interleukin (IL)-6, and nerve growth factor in the skin and IL-1ß, and IL-6 in the muscle of the post-fracture/cast limb. These data suggest that oxidative stress may contribute to the nociceptive features of the rat CRPS model. PERSPECTIVE: Vit C reduced the CRPS-like signs, oxidative stress, and the upregulation of neuropeptide production and inflammatory mediators observed after tibia fracture and casting in rats. Limiting oxidative stress by use of Vit C or alternative strategies could reduce the risk of developing CRPS after surgery or other forms of trauma.

Complex Regional Pain Syndrome After Distal Radius Fracture Is Uncommon and Is Often Associated With Fibromyalgia.

BACKGROUND: Complex regional pain syndrome (CRPS) is frequently diagnosed in patients recovering from surgery or injury. The symptoms and signs included in consensus diagnostic criteria for CRPS are expected after injury. Categorizing symptoms and signs that occur on a continuum as disproportionate or not is subjective and prone to bias. Psychiatrists and psychologists do not diagnose CRPS and instead measure and treat anxiety and catastrophic thinking on its continuum. Given the expected variation in subjective diagnoses such as CRPS, this study addresses factors associated with use of this diagnosis and how it influences care. QUESTIONS/PURPOSES: (1) Among patients recovering from fracture of the distal radius, what factors are associated with the diagnosis of CRPS? (2) Are patients diagnosed with CRPS after distal radius fractures, as opposed to those without CRPS, more likely to have a bone scan, stellate ganglion block, therapy, or subsequent surgery? METHODS: Using the Truven database, we identified 59,765 patients treated for a distal radius fracture from 2012 to 2014, of whom 114 (0.19%) were diagnosed with CRPS. The Truven Health MarketScan database is an administrative claims data set of commercially insured patients and this analysis only included patients with complete enrollment from 2012 through 2014. Bivariate analyses sought differences between patients diagnosed with and patients not diagnosed with CRPS. All factors with p < 0.05 were included in a multivariable logistic regression model. RESULTS: The covariates older age (odds ratio [OR], 1.029; 95% confidence interval [CI], 1.011-1.048; p = 0.002), gender (women at greater risk, OR, 3.86; CI, 1.99-7.49; p < 0.001), concomitant fracture of the distal ulna (OR, 1.54; CI, 1.05-2.23; p = 0.029), open fracture (OR, 0.414; CI, 0.192-0.895; p = 0.025), and comorbid fibromyalgia (OR, 16.0; CI, 4.92-51.8; p < 0.001) were independently associated with a diagnosis of CRPS among patients recovering from a fracture of the distal radius. Patients diagnosed with CRPS are more likely than other patients with a distal radius fracture to have had a bone scan (OR, 66.0; CI, 8.19-532; p < 0.001), physical or occupational therapy (OR, 3.89; CI, 2.68-5.67; p < 0.001), and subsequent wrist surgery (OR, 2.52; CI, 1.65-3.84; p < 0.001). No one had a stellate ganglion injection. CONCLUSIONS: We found that a coded diagnosis of CPRS is uncommonly applied to patients on the higher range of pain, stiffness, and limitations after fracture of the distal radius-most commonly in women and in association with another nonspecific, objectively unverifiable diagnosis (fibromyalgia)-and that this label may lead to more testing and invasive treatment. Future research should address the utility and value of diagnoses that create subjective categories for aspects of human illness that occur on a continuum. LEVEL OF EVIDENCE: Level III, prognostic study.

Modified Dorsal Approach in the Management of Lisfranc Injuries.

BACKGROUND: Open reduction and internal fixation of Lisfranc injuries has typically used multiple longitudinal incisions or a single transverse incision to approach the tarso-metatarsal joint (TMTJ). The incidence of wound-related complications is considerable. We describe a novel single-incision approach that utilizes subcutaneous windows to the medial TMTJ. METHODS: A retrospective review identified 150 patients who underwent open reduction and internal fixation for Lisfranc injuries, via the modified dorsal approach, at our center between January 2011 and June 2016. Removal of hardware (ROH) was routinely undertaken in 105 patients at a median of 210 days postoperatively. Medical records were reviewed to record patient demographics, mechanism of injury, and operative details. Outpatient notes were reviewed to identify wound-related complications, including delayed wound healing, superficial infection, wound dehiscence, deep infection, complex regional pain syndrome (CRPS), neuroma, and impaired sensation. Median age was 37 years (range, 19-78 years). Seventy-three percent of patients (110) were male. Most frequent mechanisms of injury were motor vehicle accident (MVA), 39%; motorbike accident (MBA), 19%; and fall, 18%. Sixteen percent (24) of injuries were open. Five patients required soft tissue reconstruction at the primary operation. Median follow-up was 144 (range, 27-306) weeks. RESULTS: Following the primary procedure, 14% of patients experienced wound-related complications including delayed healing (3%), superficial infection (5%), dehiscence (3%), complex regional pain syndrome (CRPS) (1%), and impaired sensation (1%). MBA injuries were at 15.1 times odds of superficial infection ( P =.01) than were MVA injuries. Following ROH, 13% of patients experienced wound-related complications, including delayed healing (2%), superficial infection (8%), dehiscence (1%), CRPS (2%), and neuroma (1%). Overall, 5 patients returned to surgery for soft tissue reconstruction for wound dehiscence. CONCLUSION: The modified dorsal approach using intervals to the midfoot offers a viable alternative with comparable wound complication rates to existing midfoot approaches. LEVEL OF EVIDENCE: Level IV, case series.

Hand lesion after arthroscopic rotator cuff repair: Association with complex regional pain syndrome.

BACKGROUND: It is known that complex regional pain syndrome (CRPS) occurs after arthroscopic rotator cuff repair (ARCR); however, few studies have investigated this complication. Therefore, the purpose of the present study was to evaluate CRPS after ARCR. METHODS: A total of 182 patients who underwent ARCR were enrolled in this study. The average age of patients was 62.8 ± 10.0 years, with an average follow-up period of 21.5 ± 38.1 months. CRPS criteria outlined by the Ministry of Health, Labor, and Welfare study team for CRPS in Japan (MHLWJ) and International Association for the Study of Pain (IASP 2005) were utilized for diagnosis. There are two rating systems for the "clinical purpose" and "research purpose" in both criteria, respectively. Clinical outcomes, including Japanese Orthopedic Association (JOA) and University of California, Los Angeles scores, were evaluated using univariate and multivariate analysis. RESULTS: CRPS exclusively occurred in the hand of the operated limb, developing within 3 months of surgery. Two or more of the following symptoms were noted in patients with the hand lesion associated with CRPS: edema (93.4%), restricted range of motion (83.4%), hyperalgesia (30.1%), paridrosis (20.4%), and atrophic change (12.2%). Under these conditions, the incidences of CRPS were 24.2% (44/182) when evaluated by the MHLWJ rating system for the "clinical purpose;" 11% (22/182) by the MHLWJ rating system for the "research purpose;" 6% (11/182) by the IASP 2005 for the "clinical purpose;" and 0.5% (1/182) by the IASP 2005 for the "research purpose." Results of multivariate analysis demonstrated that "Function" in the JOA score was a risk factor for the development of CRPS after ARCR, when evaluated by a system for the "clinical purpose" of the MHLWJ. CONCLUSION: Following ARCR, CRPS-induced hand lesions occur more frequently than is generally believed, thereby suggesting that its impact on surgical outcomes should be clarified in the future.

Dolor regional complejo tipo 1 en población pediátrica: artículo de revisión / Complex regional pain type 1 in pediatric population: review article

Dolor regional complejo se reconoce como una entidad caracterizada por dolor de distribución regional que es desproporcional al estímulo que lo provocó. Se diferencia en tipo 1 cuando no existe un daño neurológico orgánico y en tipo 2 cuando sí existe lesión neurológica de base. El diagnóstico y el tratamiento constituyen un verdadero reto. Es necesario un alto nivel de sospecha diagnóstica y la instauración de un oportuno tratamiento interdisciplinario.

Complex regional pain is a painful disorder without a known mechanism. Two different types are classified depending if there are or not a neurological structural damage. The diagnosis and treatment are real challenges to the interdisciplinary team that should identify and bring an effective treatment to the patients. Clinicians should be aware of this entity in order to prevent delay in diagnosis and provide an early and effective treatment.

The risk of pain syndrome affecting a previously non-painful limb following trauma or surgery in patients with a history of complex regional pain syndrome.

BACKGROUND AND PURPOSE: Complex regional pain syndrome (CRPS) is a challenging complication after surgery or trauma. This study sought to determine the incidence of CRPS after a second inciting event in a previously unaffected extremity in patients with a history of an ongoing CRPS diagnosis in another extremity. METHODS: A retrospective review identified patients with CRPS seen in clinic over a 20-month period. The incidence of CRPS after subsequent surgery or injury in a previous unaffected extremity was determined and compared to an average incidence reported in the literature. RESULTS: Ninety-three patients had a diagnosis of primary CRPS. Nineteen (20.4%) developed CRPS in one or more additional extremity compared to the incidence of 23.4 per 100,000 (0.0234%) in the literature (odds ratio 1069.6, p<0.0001, 95% CI 562.0-2035.7). Twenty patients had a documented secondary injury or surgery in a second extremity. Fifteen (75%) developed secondary CRPS compared to a CRPS incidence rate of 6.4% following distal radius fracture, as determined by literature review (odds ratio 11.7, p<0.001, 95% CI 5.9-23.2). CONCLUSIONS: These result suggest that patients with a history of CRPS are more likely to develop secondary CRPS compared to the rates reported in the literature among the general population. IMPLICATIONS: Patients with a history of CRPS should be counselled that they may be at risk for developing secondary CRPS if they undergo surgery or sustain trauma to another extremity.

Complex regional pain syndrome: new concepts regarding diagnosis and treatment

Antecedentes: Los autores presentan una revisión crítica sobre el cuadro clínico, el diagnóstico, clasificación y tratamientodel síndrome de dolor regional complejo, discutiendo todos los métodos de tratamiento y haciendo hincapié en que la reabilitación debe ser empleada con el fin de obtener un mejor resultado. Aspecto psicológico debe ser discutido en el tratamiento y también se anima equipo multidisciplinario para participar en él.

Background: The authors presented a critical review about the clinical picture, diagnosis, classification and treatment ofcomplex regional pain syndrome, discussing all methods of treatment and emphasizing that the reabiltation must be employed in order to obtain a better result. Psychological aspect must be involved in the treatment and also multidisciplinary team is encouraged to take part on it.