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.

Frailty Is Associated With Increased 30-Day Adverse Events and Hospitalization Costs After Primary Total Hip Arthroplasty.

BACKGROUND: Frailty can predict adverse outcomes for multiple medical conditions and surgeries but is not well studied in total hip arthroplasty (THA). We evaluate the association between Hospital Frailty Risk Score and postoperative events and costs after primary THA. METHODS: Using the National Readmissions Database, we identified primary THA patients for osteoarthritis, osteonecrosis, or hip fracture from January to November 2017. Using Hospital Frailty Risk Score, we compared 30-day readmission rate, hospital course duration, and costs between frail and nonfrail patients for each diagnosis, controlling for covariates. Thirty-day complication and reoperation rates were compared using univariate analysis. RESULTS: We identified 167,700 THAs for osteoarthritis, 5353 for osteonecrosis, and 7246 for hip fractures. Frail patients had increased 30-day readmission rates (5.3% vs 2.5% for osteoarthritis, 7.1% vs 3.3% for osteonecrosis, 8.4% vs 4.3% for fracture; P < .01), longer hospital course (3.4 vs 1.9 days for osteoarthritis, 4.1 vs 2.1 days for osteonecrosis, 6.3 vs 3.9 days for fracture; P < .01), and increased costs ($18,712 vs $16,142 for osteoarthritis, $19,876 vs $16,060 for osteonecrosis, $22,185 vs $19,613 for fracture; P < .01). Frail osteoarthritis patients had higher 30-day complication (4.4% vs 1.9%; P < .01) and reoperation rates (1.6% vs 0.93%; P < .01). Frail osteonecrosis patients had higher 30-day complication rates (5.3% vs 2.6%; P < .01). Frail hip fracture patients had higher 30-day complication (6.6% vs 3.8%; P < .01) and reoperation rates (2.9% vs 1.8%; P < .01). CONCLUSION: Frailty is associated with increased healthcare burden and postoperative events after primary THA. Further research can identify high-risk patients and mitigate complications and costs.

Reducing opioid usage in total knee arthroplasty postoperative pain management: a literature review and future directions.

Total knee arthroplasty (TKA) is a common orthopedic surgery performed with a projected 3.5 million procedures to be done by 2030. Current postoperative pain management for TKA is insufficient, as it results in extensive opioid consumption and functional decline postoperatively. This study identifies the best practices for postoperative TKA pain management through a literature review of the last three years. Studies utilizing interventional techniques (local infiltration analgesia, nerve blocks) and pharmacologic options were reviewed on PubMed, Embase, Ovid Medline and Scopus. Primary outcomes analyzed were the effect of different analgesic approaches on pain reduction, opioid use reduction and improvements in functional mobility or quadriceps strength postoperatively. Additionally, this paper explores the use of cooled radiofrequency ablation, a minimally invasive therapy, for preoperative and postoperative TKA pain management.

Lay abstract Total knee arthroplasty (TKA), also known as 'knee replacement', is a common orthopedic surgery performed with a projected 3.5 million procedures to be done by 2030. Historically, pain management after TKA has involved opioids, but in light of recent extensive opioid dependence and consumption, pain management plans that incorporate other non-opioid techniques should be considered. This study identifies the best practices for postoperative TKA pain management through a literature review of the last 3 years. Studies utilizing interventional techniques such as local analgesia and nerve blocks, as well as pharmacologic options (involving the administration of medicines), were reviewed on the following databases: PubMed, Embase, Ovid Medline and Scopus. The main outcomes analyzed were the effect of these different approaches on pain reduction, opioid use reduction and improvements in functional mobility or strength of the quadriceps muscle in the thigh following TKA surgery. Additionally, this paper explores the use of cooled radiofrequency ablation, a minimally invasive therapy, for preoperative and postoperative TKA pain management.

Recommendations for anesthetic management for intraoperative neuromodulation cases.

This paper performs a review of current literature as well as uses our single-center experience to discuss pre-operative, intra-operative and, briefly, postoperative management for dorsal column stimulators (DCSs), dorsal root ganglion (DRG) stimulators, peripheral nerve stimulators (PNSs) and intrathecal pumps. Generally, pre-operative antibiotics are recommended with discontinuation within 24 h postoperatively. For dorsal column and DRG stimulation, monitored anesthesia care or general anesthesia with intra-operative neuromonitoring is recommended; for peripheral nerve stimulation and intrathecal pump implementation, monitored anesthesia care is preferred. There is little information on appropriate anesthetic management during these forms of neuromodulation. More research is necessary to articulate specific pre-operative, intra-operative and postoperative management guidelines and recommendations for dorsal column stimulator, DRG stimulation, PNS and intrathecal pump implantation.

Neuromodulation is a procedure wherein the nerves that are responsible for pain are stimulated, for example with electrical pulses, to reduce the pain signals originating from that nerve. The implantation of neuromodulation devices requires surgery. This paper reviews current literature and provides guidelines based on our single center experience to discuss anesthetic management of patients before surgery, during surgery and after the surgery. We review management for different forms of neuromodulation including dorsal column stimulators (DCSs), dorsal root ganglion (DRG) stimulators, peripheral nerve stimulators and intrathecal pumps. We searched various online databases to find papers that discussed anesthetic management around these surgeries. Generally, starting antibiotics before the surgery and then stopping the antibiotics within 24 h after the surgery is recommended. For dorsal column and DRG stimulation, monitored anesthesia care, where patients are awake but very relaxed, or general anesthesia with neuromonitoring during the operation (so that surgeons can check the function of the nerves in real time) is recommended. For peripheral nerve stimulation and intrathecal pump implementation, monitored anesthesia care is preferred. There is little information in the literature on appropriate anesthetic management during these forms of neuromodulation. More research is necessary to articulate specific management guidelines before surgery, during surgery and after surgery for DCSs, DRG stimulation, peripheral nerve stimulator and intrathecal pump implantation.

Restorative Neurostimulation: A Clinical Guide for Therapy Adoption.

In this review, we present a comprehensive clinical approach to restorative neurostimulation, a novel form of stimulation for refractory chronic mechanical low back pain, targeting impaired neuromuscular control and degeneration of the multifidus muscle. We focus on patient identification, technique guidance, and review of the scientific background and clinical evidence. As our understanding of back pain grows, there is clear evidence that impaired neuromuscular control and consequent degeneration of the multifidus muscle contribute to mechanical low back pain development and maintenance. We provide clinical guidance regarding an implantable restorative neurostimulation system that targets impaired neuromuscular control. Supported by results from a randomized, active-sham-controlled clinical trial with long-term follow-up, we provide clinicians with a comprehensive overview and practical clinical guidance for the adoption of this therapy modality.

Vertebral Augmentation of Cancer-Related Spinal Compression Fractures: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To compare the magnitude and duration of pain relief with vertebral augmentation to any other therapy for the treatment of cancer-related vertebral compression fractures through meta-analysis of randomized controlled trials. SUMMARY OF BACKGROUND DATA: Derived from search on PubMed, EMBASE, CINAHL, Scopus, Central, Scopus, and Web of Science databases in May 2020. Studies selected were limited to randomized controlled trials comparing vertebral augmentation, either Balloon Kyphoplasty or Percutaneous Vertebroplasty (PVP) with or without additional therapy to any other intervention or placebo/sham. METHODS: The methodological quality of each included study was assessed according to the Cochrane Collaboration's domain-based framework. Random effects model, Q test, and I2 statistics were implemented. RESULTS: Of 180 records identified, 7 were considered relevant, and included 476 participants. The risk of bias was considered "Low" in all studies. In five of the studies, vertebral augmentation alone (either PVP or Balloon Kyphoplasty) comprised one group, while comparative treatments included nonsurgical management, Kiva implantation, PVP and radiofrequency therapy, PVP and chemotherapy, PVP and intrasomatic injection of steroid, and PVP with 125I seeds. Two studies compared PVP with an additional therapy against the standard of care. With regard to changes in pain severity, the effect sizes varied from 0.0 (95% -1.7 to 1.7) to -5.1 (95% -5.3 to -4.9). Most studies demonstrated a positive and statistically significant effect associated with PVP. Four of the seven studies demonstrated a clinically significant effect as well. Other than cement leakage, with an event rate of 0.24 (95% CI 0.11-0.44) or 24% (95% CI 11%-44%), there were no major adverse events consistently observed across multiple studies. CONCLUSIONS: The included randomized controlled trials demonstrated an overall positive and statistically significant effect of vertebral augmentation surgeries, such as vertebroplasty and kyphoplasty, for the treatment of cancer-related vertebral compression fractures, especially when compared with nonsurgical management, radiofrequency ablation, or chemotherapy alone.Level of Evidence: 1.

Preoperative evaluation of coagulation status in neuromodulation patients.

OBJECTIVE: The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation. METHODS: Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/µl. The authors identified risk factors for these abnormalities and described interventions. RESULTS: Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis. CONCLUSIONS: New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

Decompression Surgery versus Interspinous Devices for Lumbar Spinal Stenosis: A Systematic Review of the Literature.

In this retrospective review study, the authors systematically reviewed the literature to elucidate the efficacy and complications associated with decompression and interspinous devices (ISDs) used in surgeries for lumbar spinal stenosis (LSS). LSS is a debilitating condition that affects the lumbar spinal cord and spinal nerve roots. However, a comprehensive report on the relative efficacy and complication rate of ISDs as they compare to traditional decompression procedures is currently lacking. The PubMed database was queried to identify clinical studies that exclusively investigated decompression, those that exclusively investigated ISDs, and those that compared decompression with ISDs. Only prospective cohort studies, case series, and randomized controlled trials that evaluated outcomes using the Visual Analog Scale (VAS), Oswestry Disability Index, or Japanese Orthopedic Association scores were included. A random-effects model was established to assess the difference between preoperative and the 1-2-year postoperative VAS scores between ISD surgery and lumbar decompression. This study included 40 papers that matched our criteria. Twenty-five decompression-exclusive clinical trials with 3,386 patients and a mean age of 68.7 years (range, 31-88 years) reported a 2.2% incidence rate of dural tears and a 2.6% incidence rate of postoperative infections. Eight ISD-exclusive clinical trials with 1,496 patients and a mean age of 65.1 (range, 19-89 years) reported a 5.3% incidence rate of postoperative leg pain and a 3.7% incidence rate of spinous process fractures. Seven studies that compared ISDs and decompression in 624 patients found a reoperation rate of 8.3% in ISD patients vs. 3.9% in decompression patients; they also reported dural tears in 0.32% of ISD patients vs. 5.2% in decompression patients. A meta-analysis of the randomized controlled trials found that the differences in preoperative and postoperative VAS scores between the two groups were not significant. Both decompression and ISD interventions are unique surgical interventions with different therapeutic efficacies and complications. The collected studies do not consistently demonstrate superiority of either procedure over the other but understanding the differences between the two techniques can help tailor treatment regimens for patients with LSS.