Incidence of and Risk Factors for Complex Regional Pain Syndrome Type 1 after Surgery for Distal Radius Fractures: A Population-based Study

Analysis of Surgical Procedures on the Forearm and Hand and Their Relationship with Complex Regional Pain Syndrome: A Cross-sectional Study

Objective  Complex regional pain syndrome (CRPS) requires further understanding. Thus, the present study aimed to analyze if pre- and intraoperative factors may be related to the development of CRPS in the postoperative period. Methods  We reviewed 1,183 medical records of patients undergoing forearm and hand surgeries from 2015 to 2021. The data of interest, that is, diagnosis, incisions, synthesis material, and anesthesia, were collected, tabulated, and statistically analyzed, with subsequent calculation of the odds ratios. Results  Most patients were female, aged between 30 and 59 years, and sought the service electively (67% of the cases). The diagnoses included soft tissue trauma (43%), bone trauma (31.6%), and compressive syndromes (25.5%). During this period, 45 (3.8%) subjects developed CRPS. The statistical analysis showed that the chance of developing CRPS is twice as high in patients with compressive syndrome, especially carpal tunnel syndrome (CTS), which represented most surgeries performed in our service (24%). Two or more incisions occurred in 7.6% of the cases, which tripled the chance of developing postoperative CRPS. Gender, age, use pf synthetic material, type of anesthesia type did not statistically increase the risk of developing postoperative CRPS. Conclusion  In short, the incidence of CRPS is low; however, it is critical to know and recognize the risk factors for prevention and active screening in the postoperative period.

Complex regional pain syndrome: advances in epidemiology, pathophysiology, diagnosis, and treatment

Complex regional pain syndrome (CRPS) is a rare pain disorder that usually occurs in a limb after trauma. The features of this disorder include severe pain and sensory, autonomic, motor, and trophic abnormalities. Research from the past decade has offered new insights into CRPS epidemiology, pathophysiology, diagnosis, and treatment. Early identification of individuals at high risk of CRPS is improving, with several risk factors established and some others identified in prospective studies during the past 5 years. Better understanding of the pathophysiological mechanisms of CRPS has led to its classification as a chronic primary pain disorder, and subtypes of CRPS have been updated. Procedures for diagnosis have also been clarified. Although effective treatment of CRPS remains a challenge, evidence-based integrated management approaches provide new opportunities to improve patient care. Further advances in diagnosis and treatment of CRPS will require coordinated, international multicentre initiatives.

Complex Regional Pain Syndrome after Distal Radius Fracture-Case Report and Mini Literature Review

This study explores the impact of the complex regional pain syndrome (CRPS) on the lives and mobility of patients, with a particular focus on its emergence as a late complication of distal radius fractures (DRFs), a common occurrence, especially among an aging population. The absence of a standardized treatment for the CRPS and the challenge of predicting its occurrence make it a complex medical issue. This research aims to shed light on the effects of treating the CRPS through a case study involving a 75-year-old woman with untreated osteoporosis who experienced a Colles fracture after a fall. The initial management involved repositioning and stabilizing the fractured forearm with a plaster cast, followed by an operation using percutaneous pinning via a Kirschner wire. Subsequently, the patient developed CRPS symptoms and was admitted to the rehabilitation department three months post-fracture. The affected forearm exhibited swelling, warmth, pain, and severely limited range of motion. Treatment involved a combination of medications, physiotherapy, and kinesiotherapy. Significantly, the patient experienced notable improvement following these interventions. This study underscores the absence of a definitive standard for CRPS treatment but suggests that proper rehabilitation and pharmaceutical interventions can contribute positively to patient outcomes. The case further highlights the potential association between DRF and CRPS development, emphasizing the need for continued research in this field.

Patients With Preexisting Anxiety and Mood Disorders Are More Likely to Develop Complex Regional Pain Syndrome After Fractures

BACKGROUND

Complex regional pain syndrome (CRPS) is a multifactorial condition that may affect patients who sustain a fracture in the upper and lower extremities. Prior investigations have formed a foundation for exploring a possible association between psychiatric disorders and the development of CRPS; however, current studies are conflicted regarding the existence and temporality of a relationship between psychiatric disorders and the potential development of CRPS.

QUESTIONS/PURPOSES

(1) Are patients with preexisting anxiety and mood disorders (AMDs) at increased risk of receiving a diagnosis of CRPS after upper or lower extremity fractures? (2) Are patients with preexisting AMDs at increased risk of being diagnosed with CRPS after surgical fixation of their fracture?

METHODS

A large, retrospective cohort study was conducted using the TriNetX electronic medical record platform, which contains data from more than 100 million patients. This platform gathers data from healthcare organizations in the United States and Europe and collects comprehensive data over time that includes temporality rather than simply the binary presence or absence of conditions. The cohort included 760,595 patients older than 18 years with upper or lower extremity fractures between 2003 and 2022. Included patients had a minimum 1-year follow-up. We defined AMDs as any diagnosis of anxiety, depressive episode or disorder, a manic episode, or bipolar disorder. Patients with polytrauma or concurrent upper and lower extremity fractures were excluded to reduce confounders. CRPS I diagnosis was identified via International Classification of Diseases, Tenth Edition codes. Propensity score matching was performed to balance cohorts based on age, gender, and race. Hazard ratios and Aalen-Johansen cumulative incidence curves for the diagnosis of CRPS were calculated for patients with and without AMD diagnoses before sustaining a fracture. A subanalysis was performed in which we examined individuals in the upper and lower extremity fracture cohorts who underwent surgical treatment.

RESULTS

Patients with preexisting AMDs were at a higher risk of experiencing CRPS I than patients without AMDs were (upper extremity: HR 1.8 [95% CI 1.7 to 1.9]; p < 0.01, lower extremity: HR 2.2 [95% CI 2.0 to 2.3]; p < 0.01). Similarly, patients with preexisting AMDs were at higher risk of experiencing CRPS I after fracture fixation than patients without AMDs were (upper extremity: HR 1.3 [95% CI 1.2 to 1.5]; p < 0.01, lower extremity: HR 2.3 [95% CI 2.1 to 2.5]; p < 0.01).

CONCLUSION

Awareness of the relationship between AMDs and CRPS I will direct future research about the development of this condition and associated neurologic changes. Additionally, surgeons can address AMDs perioperatively and arrange for the treatment of these AMDs with psychiatrists, neurologists, or social work, as appropriate. Accordingly, patients with AMDs should also be made aware of the inherent risk of CRPS I after an upper or lower extremity fracture to comprehensively educate and care for this at-risk patient population.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Complications of operatively treated distal radial fractures

Distal radial fractures represent the most common fractures of the upper extremity. Operative treatment is performed for approximately one-third of distal radial fractures in the adult population. Complications following operative treatment of distal radial fractures vary depending on the treatment modality and can be stratified into preoperative and postoperative complications. Complications can occur in the near, intermediate and long term. The most common complications seen are tendon irritation and rupture, chronic regional pain syndrome (CRPS), carpal tunnel syndrome, ulnar or radial neuropathy, compartment syndrome, malunion, inadequate fixation or loss of fixation, symptomatic hardware, post-traumatic arthritis, stiffness and infection. Careful planning, treatment and patient selection can help to mitigate these complications.Level of evidence: V.

Posttraumatic arthritis and functional outcomes of nonoperatively treated distal radius fractures after 3 years

Recent studies have shown that distal radius fractures (DRFs) in elderly patients can be treated nonoperatively with good functional results after 1 year. However, scientific evidence regarding longer follow-up to assess posttraumatic arthritis (PA), complications, and functional outcomes is scarce. This prospective case series aimed to evaluate these outcomes in a cohort of patients ≥ 65-year-old with nonoperatively treated DRFs after a minimum of 3 years. The primary outcome was PA. Secondary outcomes were complications, Quick Disabilities of the Arm, Shoulder and Hand Outcome Measure (QuickDASH), Patient-Rated Wrist/Hand Evaluation (PRWHE), pain, range of motion and grip strength. The full data of 32 patients with a mean follow-up of 3.3 years were available: 10/32 patients had radiological signs of PA, but only 2 of these patients reported pain. A total of 11/32 fractures healed in malunion (> 10° dorsal angulation). There was no significant difference in QuickDASH or PRWHE from 1 year to the latest follow-up after more than 3 years. This study thus adds to the literature stating that radiological signs, including PA and malunion, do not necessarily result in symptoms. Moreover, it underpins that nonoperative treatment of these patients results in good functional outcomes after 1 and 3 years.

Incidence and risk factors for complex regional pain syndrome in radius fractures: meta-analysis

PURPOSE

This meta-analysis aimed to evaluate the incidence and risk factors for complex regional pain syndrome (CRPS) in radius fractures.

METHODS

The meta-analysis was performed using the PubMed, Embase, Scopus, and Cochrane Collaboration Library databases. Studies focusing on patients with conservative or surgically treated radius fractures leading to CRPS were included. A control group consisting of patients with radius fractures and no CRPS (-) was included. The outcome measures were incidence and risk factors. Comparative studies were also included. Data were combined using Review Manager 5.4.

RESULTS

Out of 610 studies, nine studies were included. The incidence of CRPS after radius fractures ranged from 0.19 to 13.63% (95% CI: 11.12-16.15%). Open fractures, high-energy mechanisms in radial head fractures, and associations with ulnar fractures were risk factors for CRPS [(RR: 0.98; 95% CI: 0.97-1.00), (RR: 0.18; 95% CI: 0.07-0.47), and (RR: 1.25; 95% CI: 1.17-1.35), respectively]. Other risk factors were female sex and high body mass index [(RR: 1.20; 95% CI: 1.05-1.37) and (MD: 1.17; 95% CI: 0.45-1.88)]. Psychiatric factors also increased the incidence of CRPS (RR: 2.04; 95% CI: 1.83-2.28). On the other hand, the type of surgery (external fixation or open reduction and internal fixation) and manipulations; associated comorbidities (diabetes and hypertension) together with tobacco and alcohol abuse; marital status, educational level, employment status, and socioeconomic status were not risk factors (p > 0.05).

CONCLUSION

The incidence of CRPS in radius fractures was 13.63%. Fractures with greater complexity or greater associated tissue damage, female sex, high BMI, and psychiatric disorders were risk factors for the development of CRPS.

LEVEL OF EVIDENCE

Meta-analysis of cohort and case series studies; II.

Complex Regional Pain Syndrome (CRPS) and the Value of Early Detection

PURPOSE OF REVIEW

The goal of this narrative review is to describe the current understanding of the pathology of Complex Regional Pain Syndrome (CRPS), as well as diagnostic standards and therapeutic options. We will then make the case for early recognition and management.

RECENT FINDINGS

CRPS remains an enigmatic pain syndrome, comprising several subtypes. Recent recommendations clarify diagnostic ambiguities and emphasize the importance of standardized assessment and therapy. Awareness of CRPS should be raised to promote prevention, early detection, and rapid escalation of therapy in refractory cases. Comorbidities and health costs (i.e., the socioeconomic impact) must also be addressed early to prevent negative consequences for patients.

Complex Regional Pain Syndrome: Evidence-Based Advances in Concepts and Treatments

PURPOSE OF REVIEW

This review presents the most current information about the epidemiology of complex regional pain syndrome (CRPS), classification and diagnostic criteria, childhood CRPS, subtypes, pathophysiology, conventional and less conventional treatments, and preventive strategies.

RECENT FINDINGS

CRPS is a painful disorder with multifactorial pathophysiology. The data describe sensitization of the central and peripheral nervous systems, inflammation, possible genetic factors, sympatho-afferent coupling, autoimmunity, and mental health factors as contributors to the syndrome. In addition to conventional subtypes (type I and type II), cluster analyses have uncovered other proposed subtypes. Prevalence of CRPS is approximately 1.2%, female gender is consistently associated with a higher risk of development, and substantial physical, emotional, and financial costs can result from the syndrome. Children with CRPS seem to benefit from multifaceted physical therapy leading to a high percentage of symptom-free patients. The best available evidence along with standard clinical practice supports pharmacological agents, physical and occupational therapy, sympathetic blocks for engaging physical restoration, steroids for acute CRPS, neuromodulation, ketamine, and intrathecal baclofen as therapeutic approaches. There are many emerging treatments that can be considered as a part of individualized, patient-centered care. Vitamin C may be preventive. CRPS can lead to progressively painful sensory and vascular changes, edema, limb weakness, and trophic disturbances, all of which substantially erode healthy living. Despite some progress in research, more comprehensive basic science investigation is needed to clarify the molecular mechanisms of the disease so that targeted treatments can be developed for better outcomes. Incorporating a variety of standard therapies with different modes of action may offer the most effective analgesia. Introducing less conventional approaches may also be helpful when traditional treatments fail to provide sufficient improvement.

Baseline predictors related to functional outcomes in patients older than sixty years with complex regional pain syndrome type 1 after distal radius fracture treated conservatively: a prospective observational study

PURPOSE

This study aimed to analyze baseline predictors of functional outcomes six weeks and at one year follow-up in patients older than 60 years with complex regional pain syndrome type 1 (CRPS I) after distal radius fracture (DRF).

METHODS

A total of 120 patients with CRPS I after DRF were prospectively recruited. Presumptive relevant factors were collected and analyzed as potential baseline predictors. Additionally, functional outcomes were assessed at the beginning of physiotherapy treatment, at six weeks after finishing physiotherapy treatment, and at one year follow-up. Patient-Rated Wrist Evaluation; Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire; Jamar dynamometer; and visual analog scale (VAS) were assessed.

RESULTS

All participants completed the study. At 6 weeks, the main results showed an association of lower values of grip strength with female sex (p = 0.010), intra-articular DRFs (p = 0.030), longer immobilization time (p = 0.040), lower levels of physical activity (p < 0.001), higher levels of kinesiophobia (p = 0.010), and anxiety (p = 0.020). At 1-year follow-up, the results showed an association of lower values of DASH with higher BMI (p < 0.001) and longer immobilization time (p < 0.001); and higher values of VAS showed an association with older age (p = 0.010), higher BMI (p = 0.010), and lower levels of physical activity (p = 0.040).

CONCLUSION

At six weeks, factors such as BMI, immobilization time, physical activity, and kinesiophobia are associated with lower functional outcomes. Additionally, at one year follow-up, BMI, immobilization time, and physical activity continue to be associated with lower functional outcomes in patients with CRPS I after DRF treated conservatively.

Comparison of Epidemiological Data of Complex Regional Pain Syndrome (CRPS) Patients in Relation to Disease Severity-A Retrospective Single-Center Study

A retrospective data analysis of 159 complex regional pain syndrome (CRPS) patients (n = 116 women, 73.0%, mean age 60.9 ± 14.4 years; n = 43 men, 27.0%, mean age 52.3 ± 16.7 years) was performed from 2009 to 2020. The right side was affected in 74 patients (46.5%), the left in 84 patients (52.8%), and 1 patient (0.7%) developed a bilateral CRPS. Data were analyzed for the frequency and distribution of symptoms. The number of reduction maneuvers and the number of Budapest criteria were compared in relation to the severity of CRPS. Hand and wrist (n = 107, 67.3%), followed by foot and ankle (n = 36, 22.6%) and other locations (n = 16, 10.1%) were mainly affected by CRPS. The main causes included direct trauma (n = 120, 75.5%), surgery without previous trauma (n = 25, 15.7%), other causes (n = 9, 5.7%), and spontaneous development (n = 3, 1.9%); there was also missing documentation (n = 2, 1.3%). The most common symptoms were difference in temperature (n = 156, 98.1%), limitation of movement (n = 149, 93.7%), and swelling (n = 146, 91.8%). There was no correlation between the number of reduction maneuvers and the number of Budapest criteria. In summary, patients with the following constellation are at increased risk of CRPS: a female, over 60 years old, who has fallen and has sustained a fracture in the hand or wrist with persistent pain and has been immobilized with a cast for approx. 4 weeks.

Silk proteins in reconstructive surgery: Do they possess an inherent antibacterial activity? A systematic review

The field of reconstructive surgery encompasses a wide range of surgical procedures and regenerative approaches to treat various tissue types. Every surgical procedure is associated with the risk of surgical site infections, which are not only a financial burden but also increase patient morbidity. The surgical armamentarium in this area are biomaterials, particularly natural, biodegradable, biocompatible polymers, including the silk proteins fibroin (SF) and sericin (SS). Silk is known to be derived from silkworms and is mainly composed of 60-80% fibroin, which provides the structural form, and 15-35% sericin, which acts as a glue-like substance for the SF threads. Silk proteins possess most of the desired properties for biomedical applications, including biocompatibility, biodegradability, minimal immunogenicity, and tunable biomechanical behaviour. In an effort to alleviate or even prevent infections associated with the use of biomaterials in surgery, antibacterial/antimicrobial properties have been investigated in numerous studies. In this systematic review, the following question was addressed: Do silk proteins, SF and SS, possess an intrinsic antibacterial property and how could these materials be tailored to achieve such a property?

Successful Multimodal Treatment for Complex Regional Pain Syndrome in an Adolescent with Acute Lymphoblastic Leukemia: A Case Report

Complex regional pain syndrome (CRPS) is a debilitating disorder that causes significant pain and can decrease the quality of life of affected individuals. This is the first report of CRPS in an adolescent oncology patient, whose symptoms successfully resolved with 3 weeks of intensive, multimodal, and multidisciplinary therapies. She experienced a complete return to pre-CRPS functional status within 10 weeks. The successful outcome of this case highlights the importance of early recognition of CRPS in the adolescent population and the need for a multimodal intensive treatment regimen to prevent the development of chronic pain and loss of limb function.

Dorsal bridging plates for the treatment of high and low energy distal radius fractures

Distal radius fractures are common and treatment of complex fracture pattens can be challenging. We assessed functional outcomes, radiographic analysis, and complications of 26 distal radius fractures treated with dorsal bridging plate (DBP) at a mean of 14 months post plate removal (6-34 months). Radiographic parameters were measured pre- and post-operatively and patient reported wrist evaluation scores, patient reported wrist range of movement and satisfaction scores. Mean post-operative total PRWE was 26 (range 0-76) and mean wrist mobility 52° flexion (range 10°-85°) and 50° extension (range 10°-85°). Mean post-operative patient satisfaction score was 89% (range 50-100%). Four patients developed complications (one EPL rupture and three developed CRPS). DBP can reliably restore distal radius anatomy and is associated with good functional outcome scores, return of functional range of wrist movement and high levels of patient satisfaction.

Level of Evidence

III.

Chronic post-traumatic pain: rheumatological and orthopedic aspects

Trauma causes a complex local and systemic reaction of the macroorganism, the consequences of which can be various functional, neurological and psychoemotional disorders. One of the most painful complications of injuries of the musculoskeletal system is chronic post-traumatic pain (CPTP), which occurs, depending on the severity of the damage, in 10–50% of cases. The pathogenesis of this syndrome is multifactorial and includes the development of chronic inflammation, degenerative changes (fibrosis, angiogenesis, heterotopic ossification), pathology of the muscular and nervous systems, neuroplastic changes leading to the development of central sensitization, as well as depression, anxiety and catastrophization. Risk factors for CPTP should be considered the severity of injury, comorbid diseases and conditions (in particular, obesity), stress and serious trauma-related experiences (within the framework of post-traumatic stress disorder), the development of post-traumatic osteoarthritis and chronic tendopathy, genetic predisposition, deficiencies in treatment and rehabilitation in the early period after injury. To date, there is no clear system of prevention and treatment of CPTP. Considering the pathogenesis of this suffering, adequate anesthesia after injury, active anti–inflammatory therapy (including local injections of glucocorticoids), the use of hyaluronic acid, slow-acting symptomatic agents and autologous cellular preparations – platelet-riched plasma, mesenchymal stem cells, etc. are of fundamental importance. However, therapeutic and surgical methods of CPTP control require further study

Salivary biomarkers in breast cancer diagnosis: A systematic review and diagnostic meta-analysis

BACKGROUND

Salivary diagnostics and their utility as a nonaggressive approach for breast cancer diagnosis have been extensively studied in recent years. This meta-analysis assesses the diagnostic value of salivary biomarkers in differentiating between patients with breast cancer and controls.

METHODS

We conducted a meta-analysis and systematic review of studies related to salivary diagnostics published in PubMed, EMBASE, Scopus, Ovid, Science Direct, Web of Science (WOS), and Google Scholar. The articles were chosen utilizing inclusion and exclusion criteria, as well as assessing their quality. Specificity and sensitivity, along with negative and positive likelihood ratios (NLR and PLR) and diagnostic odds ratio (DOR), were calculated based on random- or fixed-effects model. Area under the curve (AUC) and summary receiver-operating characteristic (SROC) were plotted and evaluated, and Fagan's Nomogram was evaluated for clinical utility.

RESULTS

Our systematic review and meta-analysis included 14 papers containing 121 study units with 8639 adult subjects (4149 breast cancer patients and 4490 controls without cancer). The pooled specificity and sensitivity were 0.727 (95% CI: 0.713-0.740) and 0.717 (95% CI: 0.703-0.730), respectively. The pooled NLR and PLR were 0.396 (95% CI: 0.364-0.432) and 2.597 (95% CI: 2.389-2.824), respectively. The pooled DOR was 7.837 (95% CI: 6.624-9.277), with the AUC equal to 0.801. The Fagan's nomogram showed post-test probabilities of 28% and 72% for negative and positive outcomes, respectively. We also conducted subgroup analyses to determine specificity, sensitivity, DOR, PLR, and NLR based on the mean age of patients (≤52 or >52 years old), saliva type (stimulated and unstimulated saliva), biomarker measurement method (mass spectrometry [MS] and non-MS measurement methods), sample size (≤55 or >55), biomarker type (proteomics, metabolomics, transcriptomics and proteomics, and reagent-free biophotonic), and nations.

CONCLUSION

Saliva, as a noninvasive biomarker, has the potential to accurately differentiate breast cancer patients from healthy controls.

Determinants of Complex Regional Pain Syndrome Type I among Radial Head Fracture Patients with Unilateral Arthroplasty

OBJECTIVE

This study aims to assess the proportions of complex regional pain syndrome type I (CRPS I) in radial head fracture patients undergoing unilateral arthroplasty and to explore associated factors.

METHODS

This is a prospective observational study. From March 2016 to May 2019, a total of 221 adult patients with radial head fracture patients were included in consecutive studies and completed the 1-year follow-up. All patients were treated by unilateral arthroplasty. At each follow-up visit, the visual analogue scale was used to measure patients' pain level. Occurrence of CRPS I, which was diagnosed by Budapest criteria, was the main outcome collected at baseline and the 1-, 3-, 6-, and 9-month follow-ups. The baseline data were collected before surgery and included demographic and clinical data. Independent t-tests and χ² tests were used as univariate analyses to compare the baseline data of patients with and without CRPS I. Multivariate analysis (Backword-Wald) was used to identify factors independently associated with CRPS I.

RESULTS

The proportion of CRPS I cases among radial head fracture patients undergoing unilateral arthroplasty was 11% (n = 24). A total of 19 (79%) patients were diagnosed with CRPS I within 1 month after surgery. Multivariable logistic regression analysis revealed that female gender (odds ratios [OR]: 1.537; 95% confidence interval [CI]: 1.138-2.072), age younger than 60 years (OR: 1.682; 95% CI: 1.246-2.267), moderate and severe Mayo Elbow Performance Score (MEPS) pain (OR: 3.229; 95% CI: 2.392-4.351) and anxiety (OR: 83.346; 95% CI: 61.752-112.320) were independently associated with CRPS I.

CONCLUSIONS

This exploratory study reported that the incidence of CRPS I developing after radial head arthroplasty was 11%. Female sex, younger age, moderate and severe MEPS pain and anxiety patients seems more likely to develop CRPS I.

Microvascular Barrier Protection by microRNA-183 via FoxO1 Repression: A Pathway Disturbed in Neuropathy and Complex Regional Pain Syndrome

Blood nerve barrier disruption and edema are common in neuropathic pain as well as in complex regional pain syndrome (CRPS). MicroRNAs (miRNA) are epigenetic multitarget switches controlling neuronal and non-neuronal cells in pain. The miR-183 complex attenuates hyperexcitability in nociceptors, but additional non-neuronal effects via transcription factors could contribute as well. This study explored exosomal miR-183 in CRPS and murine neuropathy, its effect on the microvascular barrier via transcription factor FoxO1 and tight junction protein claudin-5, and its antihyperalgesic potential. Sciatic miR-183 decreased after CCI. Substitution with perineural miR-183 mimic attenuated mechanical hypersensitivity and restored blood nerve barrier function. In vitro, serum from CCI mice und CRPS patients weakened the microvascular barrier of murine cerebellar endothelial cells, increased active FoxO1 and reduced claudin-5, concomitant with a lack of exosomal miR-183 in CRPS patients. Cellular stress also compromised the microvascular barrier which was rescued either by miR-183 mimic via FoxO1 repression or by prior silencing of Foxo1. PERSPECTIVE: Low miR-183 leading to barrier impairment via FoxO1 and subsequent claudin-5 suppression is a new aspect in the pathophysiology of CRPS and neuropathic pain. This pathway might help untangle the wide symptomatic range of CRPS and nurture further research into miRNA mimics or FoxO1 inhibitors.

Estimating baseline kidney function in hospitalised adults with acute kidney injury

AIM

Baseline serum creatinine values are required to diagnose acute kidney injury but are often unavailable. We evaluated four conventional equations to estimate creatinine. We then developed and validated a new equation corrected by age and gender.

METHODS

We retrospectively examined adults who, at first hospital admission, had available baseline creatinine data and developed acute kidney injury ≥ 24 hours after admission. We split the study population: 50% (derivation) to develop a new linear equation and 50% (validation) to compare against conventional equations for bias, precision, and accuracy. We stratified analyses by age and gender.

RESULTS

We studied 3,139 hospitalised adults (58% male, median age 71). Conventional equations performed poorly in bias and accuracy in patients aged < 60 or ≥ 75 (68% of the study population). The new linear equation had less bias and more accuracy. There were no clinically significant differences in precision. The median (95% confidence interval) difference in creatinine values estimated via the new equation minus measured baselines was 0.9 (-3.0, 5.9) and -0.5 (-7.0, 3.7) μmol/L in female patients 18-60 and 75-100, and -1.5 (-4.2, 2.2) and -7.8 (-12.7, -3.6) μmol/L in male patients 18-60 and 75-100 respectively. The new equation improved reclassification of KDIGO AKI stages compared to the MDRD II equation by 5.0%.

CONCLUSION

Equations adjusted for age and gender are less biased and more accurate than unadjusted equations. Our new equation performed well in terms of bias, precision, accuracy, and reclassification.

Determinants of complex regional pain syndrome type I in patients with scaphoid waist fracture- a multicenter prospective observational study

Background

The aim of this prospective study was to assess the incidence of complex regional pain syndrome type I (CRPS I) in patients with scaphoid waist fracture and to explore associated factors.

Methods

This was a multicenter, prospective observational study. Demographic, imaging indicators and clinical data were collected before the conservative treatment of scaphoid waist fracture patients. The occurrence of CRPS I and pain condition were the main outcomes. To explore the factors associated with CRPS I, multivariate logistic regression model was used.

Results

A total of 493 scaphoid waist fracture participants undergoing conservative treatment were recruited for this study. The incidence of CRPS I was 20% (n = 87). The average time between injury and the onset of CRPS I was 6.7 ± 2.1 weeks. Multivariable logistic regression analysis revealed that female sex (odds ratio (OR): 1.669; 95% confidence interval (CI): 1.189–2.338), diabetes mellitus (OR: 3.206; 95% CI: 2.284–4.492), and severe pain condition before treatment (visual analog scale (VAS) score more than 4 cm) (OR: 27.966; 95% CI: 19.924–39.187) were independently associated with CRPS I.

Conclusions

Patients suffering from scaphoid waist fracture may be at a higher risk of CRPS I, especially in women with diabetes mellitus who report severe pain before treatment. Early screening and regular follow up evaluation are recommended in these patients.

Complex Regional Pain Syndrome: A Comprehensive Review

Complex regional pain syndrome (CRPS) is a chronic pain condition often involving hyperalgesia and allodynia of the extremities. CRPS is divided into CRPS-I and CRPS-II. Type I occurs when there is no confirmed nerve injury. Type II is when there is known associated nerve injury. Female gender is a risk factor for developing CRPS. Other risk factors include fibromyalgia and rheumatoid arthritis. Unfortunately, the pathogenesis of CRPS is not yet clarified. Some studies have demonstrated different potential pathways. Neuropathic inflammation, specifically activation of peripheral nociceptors of C-fibers, has been shown to play a critical role in developing CRPS. The autonomic nervous system (ANS) is involved. Depending on whether it is acute or chronic CRPS, norepinephrine levels are either decreased or increased, respectively. Some studies have suggested the importance of genetics in developing CRPS. More consideration is being given to the role of psychological factors. Some association between a history of depression and/or post-traumatic stress disorder (PTSD) and the diagnosis of CRPS has been demonstrated. Treatment modalities available range from physical therapy, pharmacotherapy, and interventional techniques. Physical and occupational therapies include mirror therapy and graded motor imagery. Medical management with non-steroidal anti-inflammatory drugs (NSAIDs) has not shown significant improvement. There have been supporting findings in the use of short-course steroids, bisphosphonates, gabapentin, and ketamine. Antioxidant treatment has also shown some promise. Other pharmacotherapies include low-dose naltrexone and Botulinum toxin A (BTX-A). Sympathetic blocks are routinely used, even if their short- and long-term effects are not clear. Finally, spinal cord stimulation (SCS) has been used for decades. In conclusion, CRPS is a multifactorial condition that still requires further studying to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options. Future studies are warranted to better understand this syndrome. This will provide an opportunity for better prevention, diagnosis, and treatment of CRPS.

Common Complications of Distal Radial Fractures

Distal radial fractures are associated with good outcomes; however, although they occur at low rates, complications can significantly impair treatment success. Therefore, the treating surgeon should be aware of potential complications associated with each treatment type and how to best prevent them. Although certain patient-specific and fracture-specific factors may increase the risk of adverse outcomes, most are nonmodifiable risk factors at the time of presentation, so it is imperative that every effort is made to mitigate these risk factors to prevent long-term morbidity. Patients should be well-informed about these complications and potential symptoms so that they can be addressed expeditiously.

Complex Regional Pain Syndrome and Distal Radius Fracture: Etiology, Diagnosis, and Treatment

Complex regional pain syndrome (CRPS) is a chronic pain condition characterized by a constellation of signs and symptoms including pain out of proportion to the injury or insult, autonomic dysfunction, trophic changes, and impaired function. CRPS may occur following either conservative or surgical management of distal radius fractures and can significantly complicate the trajectory of a patient's recovery. Although the incidence, diagnosis, prevention, and treatment of this condition have been extensively studied, optimal methods to identify, prevent, and treat this condition remain controversial. This article reviews the available literature on the diagnosis and treatment of CRPS in distal radius fractures.

Is Therapy Needed After Distal Radius Fracture Treatment, What Is the Evidence?

The role of hand therapy in management of distal radius fractures remains unclear. Some evidence demonstrates that initiating early range of motion and urging patients to return to routine activities of daily living as soon as possible may produce favorable outcomes that are as effective as formal supervised therapy. Extended supervised therapy does not appear to impact outcomes and a single instruction session with a home-based program produces similar results. Although we feel that formal structured therapy may have a role in select high-risk patients, the literature remains unclear on which patients would benefit most from formal supervised therapy.

The challenge of recognizing severe pain and autonomic abnormalities for early diagnosis of CRPS

OBJECTIVES

Complex regional pain syndrome (CRPS) is a disabling usually post-traumatic pain condition. International guidelines emphasize early diagnosis for treatment and improved outcome. Early intense and persistent pain along with features of autonomic dysfunction in the first week's post-injury are early warning signs for development of CRPS. We have previously reported a delayed diagnosis of CRPS. The main purpose of the present study was to investigate possible causes of a delayed diagnosis, with a special focus of recognition of risk factors.

METHODS

A total of 52 CRPS 1 (without detectable nerve damage) and CRPS 2 (with evidence of nerve lesion) patients were included in the study. When examined at OUS-Rikshospitalet, we retrospectively asked the patients on the development of pain and autonomic abnormalities from the time of the eliciting injury, performed a thorough clinical investigation with an emphasis on signs of autonomic failure and compared symptoms and clinical findings with such information in previous medical records. We also evaluated symptoms and signs according to the type of injury they had suffered.

RESULTS

Of a total of 52 patients (30 women and 22 men, mean age 39.0 years at the time of injury), 34 patients had CRPS type 1 (65.4%) and 18 CRPS type 2 (34.6%), 25 patients with pain in the upper and 27 in the lower extremity. A total of 35 patients (67.3%) were diagnosed with CRPS (following mean 2.1 years) prior to the investigation at OUS-Rikshospitalet (mean 4.86 years following injury). Mean time from injury to diagnosis was 33.5 months (SD 30.6) (2.8 years) for all patients. In retrospect, all 17 patients first diagnosed at OUS met the CRPS diagnosis at an earlier stage. All patients retrospectively reported intense pain (numeric rating scale > 7) from the time of injury with a large discrepancy to previous medical records which only stated intense pain in 29.4% of patients with CRPS type 1 and 44.4% of patients with CRPS type 2 within the first four months. While the patients reported an early onset of autonomic dysfunction, present in 67.3 and 94.2% of the patients within one week and one month, respectively, reports of autonomic abnormalities within the first four months was far less (maximum in 51.7% of patients with CRPS type 1 and in 60% in CRPS 2). In 10 patients with CRPS type 1, no symptom nor sign of autonomic abnormalities was reported.

CONCLUSIONS

We still find a significant delay in the diagnosis of CRPS. There is a large discrepancy between both self-reporting of intense, disproportionate pain, as well as symptoms of autonomic abnormalities from the time of injury, and documentation in previous medical records. Our findings suggest a lack of awareness of risk factors for the development of CRPS, such as early intense pain and autonomic abnormalities without recovery, contributing to delayed diagnosis. The present results suggest causes of delayed CRPS-diagnosis. An increased attention to early warning signs/risk factors may improve diagnosis of CRPS.

Surgical comfort and clinical outcomes of MIPO with an extra-short plate designed for distal radius fractures

OBJECTIVES

Volar locking plates (VLPs) are increasingly used for distal radius fractures (DRFs) with minimally invasive plate osteosynthesis (MIPO), but surgery learning curves could be long. The purpose of this study was to assess a new extra-short plate with two locking diaphyseal divergent screws, specifically designed for MIPO, preserving the pronator quadratus muscle.

MATERIALS AND METHODS

This retrospective study consisted of three phases: (i) the evaluation of surgical comfort with the incision size and the duration of 59 consecutive surgeries using the extra-short plate in DRFs; (ii) the verification of the implant ability to maintain radiographic indices compared immediately postoperatively and at consolidation. They included radial inclination (RI), volar tilt (VT) and ulnar variance (UV); (iii) the assessment of clinical outcomes at last follow-up through: pain measured on the visual analogue scale (VAS), QuickDASH score, patient-rated wrist evaluation (PRWE) score, grip strength, range of motion and complications.

RESULTS

In the first phase: mean incision size was 32 mm, and mean operative time was 28.5 min. In the second phase, there was no statistical difference between the two measures of the indices studied. In the third phase, mean follow-up time was 14.2 months, VAS score was 1.1, QuickDASH score was 11.4/100, and PRWE score was 9.5/100. Flexion was 91%, extension was 94%, and grip strength was 86% compared to the contralateral side.

CONCLUSION

The surgical comfort may be related to short operative time and incision. The implant allowed maintaining the radiographic indices without secondary displacement. Functional clinical outcomes were satisfactory. This extra-short plate design belongs to a novel generation of VLPs.

Novel immune biomarkers in complex regional pain syndrome

We investigated serum levels of 29 cytokines and immune-activated kynurenine and tetrahydrobiopterin pathway metabolites in 15 complex regional pain syndrome (CRPS) subjects and 14 healthy controls. Significant reductions in interleukin-37 and tryptophan were found in CRPS subjects, along with positive correlations between kynurenine/tryptophan ratio and TNF-α levels with kinesiophobia, tetrahydrobiopterin levels with McGill pain score, sRAGE, and xanthurenic acid and neopterin levels with depression, anxiety and stress scores. Using machine learning, we identified a set of binary variables, including IL-37 and GM-CSF, capable of distinguishing controls from established CRPS subjects. These results suggest possible involvement of various inflammatory markers in CRPS pathogenesis.

A randomized controlled trial on Aspirin and complex regional pain syndrome after radius fractures

Complex regional pain syndrome (CRPS) is often diagnosed in patients who are recovered with surgery or injury. CRPS is usually diagnosed in patients recovering from distal radius fractures. The aim of study was the effects of aspirin in prevention of the complex regional pain syndrome (CRPS) following a fracture of distal radius. In a double-blind, randomized controlled trial, 91 patients with unilateral extra-articular distal radius fractures were randomly allocated to receive either placebo (PLA) or 500 mg of aspirin (ASA) daily for 7 days. The effect of aspirin on the occurrence of CRPS was evaluated. The patients were assessed clinically and radiographically in the second, fourth and twelfth weeks by a physician who was unaware of the treatment allocation. Ninety-one patients (ASA, n=44; PLA, n=47) were enrolled in the study. The prevalence of CRPS in all patients was 16.5%. The prevalence of CRPS in the aspirin group was lower (13.6%) than the placebo group (19.1%), but this difference was not statistically significant. The only significant difference was the lower rate of regional osteoporosis seen in the radiographs of aspirin group. Mean age was significantly higher in the patients with CRPS. Also, comminuted distal radius fractures (A3-type) were significantly more common in the patients with CRPS. Administration of aspirin in patients with a distal radius fracture was associated with a lower incidence of CRPS, but, not statistically significant. Further investigations needs to be done with a larger sample size, longer follow-up period and multi-center design.

Complex syndromes of chronic pain, fatigue and cognitive impairment linked to autoimmune dysautonomia and small fiber neuropathy

Chronic fatigue syndrome, postural orthostatic tachycardia syndrome, complex regional pain syndrome and silicone implant incompatibility syndrome are a subject of debate among clinicians and researchers. Both the pathogenesis and treatment of these disorders require further study. In this paper we summarize the evidence regarding the role of autoimmunity in these four syndromes with respect to immunogenetics, autoimmune co-morbidities, alteration in immune cell subsets, production of autoantibodies and presentation in animal models. These syndromes could be incorporated in a new concept of autoimmune neurosensory dysautonomia with the common denominators of autoantibodies against G-protein coupled receptors and small fiber neuropathy. Sjogren's syndrome, which is a classical autoimmune disease, could serve as a disease model, illustrating the concept. Development of this concept aims to identify an apparently autoimmune subgroup of the disputable disorders, addressed in the review, which may most benefit from the immunotherapy.