Socioeconomic Disparities in the Utilization of Spinal Cord Stimulation Therapy in Patients with Chronic Pain.

OBJECTIVES: Spinal cord stimulation (SCS) therapies are used in the management of patients with complex regional pain syndrome I (CRPS I) and failed back surgery syndrome (FBSS). The purpose of this study was to investigate the racial and health insurance inequalities with SCS therapy in patients with chronic pain who had CRPS I and FBSS. METHODS: Patients with chronic pain who had a discharge diagnosis of FBSS and CRPS I were identified using the National Inpatient Sample database. Our primary outcome was defined as the history of SCS utilization by race/ethnicity, income quartile, and insurance status. Multivariable logistic regression was used to determine the variables associated with utilization of SCS therapy. RESULTS: Between 2011 and 2015, 40,858 patients who were hospitalized with a primary diagnosis of FBSS and/or CRPS I were identified. Of these patients, 1,082 (2.7%) had a history of SCS therapy. Multivariable regression analysis revealed that compared to White patients, Black and Hispanic patients had higher odds of having SCS therapy (Black patients: odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.12 to 1.77; P = 0.003; Hispanic patients: OR = 1.41; 95% CI, 1.10 to 1.81; P = 0.007). Patients with private insurance had significantly higher odds of having SCS therapy compared with those with Medicare (OR = 1.24; 95% CI, 1.08 to 1.43; P = 0.003). Compared to patients with Medicare, Medicaid patients had lower odds of having SCS therapy (OR = 0.50; 95% CI, 0.36 to 0.70; P < 0.001). CONCLUSIONS: Our study suggests that socioeconomic disparities may exist in the utilization of SCS among hospitalized patients with CRPS I and FBSS the United States. However, confirming these data from other administrative databases, in the outpatient setting, may shed more insight.

Current Concepts of Minimally Invasive Treatment Options for Plantar Fasciitis: a Comprehensive Review.

PURPOSE OF REVIEW: Chronic foot pain constitutes a large portion of the chronic pain burden in the overall population. Plantar fasciitis is one of the most common and most easily identifiable causes of chronic foot pain. The syndrome has been estimated to cause 11 to 15% of foot pain visits, requiring professional care. Moreover, studies have suggested that 1 in 10 people will develop plantar fasciitis at some point in their life. Conservative management has been shown to be effective and considered first-line treatment. Minimally invasive treatment options are typically reserved for those who fail conservative management. With the advent of new techniques and improvements in current therapeutic options, there has been an expansion of available minimally invasive treatment options. The purpose of this review is to provide a comprehensive update on the current understanding of minimally invasive treatments of plantar fasciitis. RECENT FINDINGS: This review shows that conservative management continues to be the first-line therapy, whereas other treatment options were those who failed conservative management using modern techniques that have shown improving effectiveness, with successful restoration of patient functionality, recovery, and satisfaction. However, a multitude of these minimally invasive treatment options are evolving. CONCLUSION: While conservative management continues to be the mainstay of treatment for plantar fasciitis, multiple minimally invasive treatment options are emerging with potential effectiveness in reducing pain and improving the function.

Neuropathic Pain and Sickle Cell Disease: a Review of Pharmacologic Management.

PURPOSE OF REVIEW: Sickle cell disease (SCD) remains among the most common and severe monogenic disorders present in the world today. Although sickle cell pain has been traditionally characterized as nociceptive, a significant portion of sickle cell patients has reported neuropathic pain symptoms. Our review article will discuss clinical aspects of SCD-related neuropathic pain, epidemiology of neuropathic pain among individuals with SCD, pain mechanisms, and current and future potential pharmacological interventions. RECENT FINDINGS: Neuropathic pain in SCD is a complicated condition that often has a lifelong and significant negative impact on life; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous, and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Our review article outlines several pharmacological modalities which may be employed to treat neuropathic pain in SCD patients.

Factors associated with academic rank among chronic pain medicine faculty in the USA.

BACKGROUND: Numerous factors are considered in the academic promotion of pain medicine physicians. In this study, we investigated the importance of research productivity, career duration, leadership, and gender on attaining professorship in chronic pain medicine fellowship programs in the USA. METHODS: We identified 98 pain fellowship programs in the American Medical Association Fellowship and Residency Electronic Interactive Database. Faculty demographics and institutional characteristics were obtained from institutional websites, and h-index (number of publications (h) cited at least h times) and m-index (h-index divided by research career duration) were calculated from Scopus. A nested mixed effect hierarchical modeling was used to determine factors that were associated with attaining professorship. RESULTS: A total of 696 chronic pain medicine faculty members from 98 academic pain fellowship programs were identified, of whom 74.7% were males. For the 15.5% who were full professors, the median h-index was 16.5 (6.0 to 30.0), the median career duration was 20.5 (16.0 to 27.0) years, and the median m-index was 0.7 (0.3 to 1.3). In an adjusted analysis, the top quartile (compared with bottom) h-index (OR 6.27; 95% CI: 2.11 to 18.59), publication citations (OR 1.13; 95% CI: 1.10 to 1.21), division chief position (OR 3.72; 95% CI: 1.62 to 8.50), institutions located in the western region (OR 3.81; 95% CI: 1.52 to 9.57), and graduating from a foreign medical school (OR 1.98; 95% CI: 1.10 to 3.92) were independently associated with attaining professorship (p<0.05), but gender was not (p=0.71). CONCLUSIONS: Our study shows that, higher h-index, publication citations, division chief position, affiliation at a lower tier medical school, and location in the Western region were independently associated with full professorship, whereas gender was not. The identified variables for professorship may be considered as factors in faculty promotions.

The Role of the Cannabinoid System in Pain Control: Basic and Clinical Implications.

PURPOSE OF REVIEW: The purpose of this review is to provide a comprehensive update of the different known components of the endogenous cannabinoid system and the mechanisms of action, as it applies to analgesia. RECENT FINDINGS: Following the discovery of the endogenous cannabinoid system in the early 1990s and the subsequent characterization of the cannabinoid receptor, there has been a renewed interest in cannabinoid research. Recent work has demonstrated its efficacy as a pharmacologic agent. There is limited evidence in the literature about the understanding of the endocannabinoid system and its role in the treatment and management of acute and chronic pain. Further work may elucidate additional roles for the endocannabinoid system within our nervous system and, moreover, additional subtypes of cannabinoid receptors have yet to be discovered. Cannabinoid compounds mediate their biological effects via binding and subsequent activation of cannabinoid receptors. These receptors are located throughout the body and make up the endocannabinoid system. These receptors are best understood and have been cloned, type 1 (CB1) and type 2 (CB2) [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)] [ (1, 2)]. The CB2 receptor is located primarily in the immune system. CB1 receptors are primarily located in the nervous system with the highest concentrations in the brain and lower concentrations in the spine and peripheral nervous tissues. Cannabinoids may be promising treatments for neuropathic pain with limited evidence, whereas, the evidence for other uses is insufficient.

A Comprehensive Update on the Treatment and Management of Postdural Puncture Headache.

PURPOSE OF REVIEW: The purpose of this manuscript is to provide a comprehensive review of postdural puncture headache (PDPH) with a focus on epidemiology, pathophysiology, treatment, and prophylaxis. RECENT FINDINGS: PDPH is an adverse iatrogenic complication of neuraxial anesthesia that occurs following inadvertent puncture of the dura after epidural or spinal anesthesia. The overall incidence of PDPH after neuraxial procedures varies from 6 to 36%. The occurrence of PDPH can lead to increased patient morbidity, delayed discharge, and increased readmission. PDPH is a self-limiting postural headache that most often will resolve within 1 week, without need for treatment. Various prophylactic measures have been studied; however, more studies have been recommended to be undertaken in order to establish a proven benefit. For mild PDPH, conservative treatments are currently focused around bed rest, as well as oral caffeine. For moderate-to-severe PDPH, epidural blood patch (EBP) remains the most effective treatment; however, this invasive treatment is not without inherent risks. Further less invasive treatments have been explored such as epidural saline, dextran 40 mg solutions, hydration, caffeine, sphenopalatine ganglion blocks, greater occipital nerve blocks, and surgical closure of the gap; all have shown promise. Further studies are essential to prove efficacy as well as safety over the proven treatment of epidural blood patches. There is still limited evidence in literature about the understanding of PDPH and optimal treatment.

Current Concepts in the Management of Vertebral Compression Fractures.

PURPOSE OF REVIEW: This comprehensive review of current concepts in the management of vertebral compression fractures is a manuscript of vertebral augmentation literature of risk factors, clinical presentation, and management. The objective of this review is to compare outcomes between multiple augmentation techniques and ongoing discussions of effectiveness of vertebral augmentation procedures. RECENT FINDINGS: Vertebral compression fractures (VCFs) are a prevalent disease affecting approximately 1.5 million US adults annually. VCFs can cause severe physical limitations, including back pain, functional disability, and progressive kyphosis of the thoracic spine that ultimately results in decreased appetite, poor nutrition, impaired pulmonary function, and spinal cord compression with motor and sensory deficits. The deconditioning that affects patients with vertebral compression fractures leads to mortality at a far higher rate than age-matched controls. The management of vertebral compression fractures has been extensively discussed with opponents arguing in favor or restricting conservative management and against augmentation, while proponents argue in favor of augmentation. The literature is well established in reference to the effects on mortality when patients undergo treatment with vertebral augmentation; in over a million patients with vertebral compression fractures treated with vertebral augmentation as compared with patients treated with non-surgical management, the patients receiving augmentation performed well with a decrease in morbidity and mortality. Summary of the literature review shows that understanding the risk factors, appropriate clinical evaluation, and management strategies are crucial. Analysis of the evidence shows, based on level I and II studies, balloon kyphoplasty had significantly better and vertebroplasty tended to have better pain reduction compared with non-surgical management. In addition, balloon kyphoplasty tended to have better height restoration than vertebroplasty.

A Comprehensive Review of the Treatment and Management of Pain in Sickle Cell Disease.

PURPOSE OF REVIEW: Sickle cell disease (SCD) is a hematological disorder which leads to serious complications in multiple organ systems. While significant research has addressed many of the effects of acute pain episodes and end-organ damage connected to this disease, little has approached the chronic pain state associated with this condition. RECENT FINDINGS: Associated chronic pain represents a significant detractor from the quality of life experienced by these patients, affecting over half of those with SCD on more days than not. Current treatment typically is centered upon preventing and responding to acute vasoocclusive crises, presumably because this is the most common reason for hospitalization in these patients. The lack of management of chronic pain symptoms leaves many with SCD in a state of suffering. In this review, the treatment methodologies of SCD patients are examined including alternative treatments, both pharmaceutical and non-pharmaceutical, as well as procedural approaches specifically aimed at reducing chronic pain in these patients.

Correction to: Role of Alpha-2-Microglobulin in the Treatment of Osteoarthritic Knee Pain: a Brief Review of the Literature.

The original publication listed author Alan Kaye as "A. Kaye," but his name should read "A.D. Kaye." The correct author name is presented in this article.

Minimally Invasive Treatment of Chronic Ankle Instability: a Comprehensive Review.

PURPOSE OF REVIEW: Chronic ankle pain is a prevalent and significant cause of chronic pain. While the definition of chronic ankle pain is heterogeneous and poorly defined in the literature, systematic reviews and meta-analyses have estimated this condition to be a prevalent and debilitating source of chronic pain. The most identifiable and prominent cause of chronic ankle pain is chronic ankle instability (CAI), a condition defined by instability of the ankle-joint complex. It is a common consequence of lateral ankle sprains or ligamentous injuries and can be described as a failure of the lateral ankle joint complex after an acute, or recurring, ankle injury. The objective of this manuscript is to provide a comprehensive review of CAI diagnosis and our current understanding of minimally invasive treatment options. RECENT FINDINGS: First-line treatment is conservative management, some of which includes neuromuscular rehabilitation, balance training, nonsteroidal anti-inflammatory drugs (NSAIDs), manual mobilization, ice therapy, and compression. While conservative management is effective, additional treatments for those who fail conservative management, or who seek alternative options also have been explored. Recent advances and modern techniques have expanded available treatment options, many of which are becoming less invasive, and have shown improving functionality, recovery, and patient satisfaction. Minimally invasive treatments highlighted in this review include: arthroscopic surgery, steroid injections, plasma-rich plasma injections, hyaluronic acid (HA) injections, medicinal signaling cell injections, radiofrequency therapies, and shockwave therapies. This review will discuss some of these current treatments for minimally invasive treatment of CAI, as well as suggest novel treatments for clinical trials and further investigation.

Carpal Tunnel Release Surgery- A Systematic Review of Open and Endoscopic Approaches.

CONTEXT: Carpal tunnel syndrome (CTS) is the most frequent peripheral compression-induced neuropathy observed in patients worldwide. Surgery is necessary when conservative treatments fail and severe symptoms persist. Traditional Open carpal tunnel release (OCTR) with visualization of carpal tunnel is considered the gold standard for decompression. However, Endoscopic carpal tunnel release (ECTR), a less invasive technique than OCTR is emerging as a standard of care in recent years. EVIDENCE ACQUISITION: Criteria for this systematic review were derived from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two review authors searched PubMed, MEDLINE, and the Cochrane Database in May 2018 using the following MeSH terms from 1993-2016: 'carpal tunnel syndrome,' 'median nerve neuropathy,' 'endoscopic carpal tunnel release,' 'endoscopic surgery,' 'open carpal tunnel release,' 'open surgery,' and 'carpal tunnel surgery.' Additional sources, including Google Scholar, were added. Also, based on bibliographies and consultation with experts, appropriate publications were identified. The primary outcome measure was pain relief. RESULTS: For this analysis, 27 studies met inclusion criteria. Results indicate that ECTR produced superior post-operative pain outcomes during short-term follow-up. Of the studies meeting inclusion criteria for this analysis, 17 studies evaluated pain as a primary or secondary outcome, and 15 studies evaluated pain, pillar tenderness, or incision tenderness at short-term follow-up. Most studies employed a VAS for assessment, and the majority reported superior short-term pain outcomes following ECTR at intervals ranging from one hour up to 12 weeks. Several additional studies reported equivalent pain outcomes at short-term follow-up as early as one week. No study reported inferior short-term pain outcomes following ECTR. CONCLUSIONS: ECTR and OCTR produce satisfactory results in pain relief, symptom resolution, patient satisfaction, time to return to work, and adverse events. There is a growing body of evidence favoring the endoscopic technique for pain relief, functional outcomes, and satisfaction, at least in the early post-operative period, even if this difference disappears over time. Several studies have demonstrated a quicker return to work and activities of daily living with the endoscopic technique.

Intravenous Lidocaine Infusion for the Management of Early Postoperative Pain: A Comprehensive Review of Controlled Trials.

Previously used as anti-arrhythmic, intravenous lidocaine infusion is becoming popular for use in management of acute pain. There is still much to be understood about its pharmacokinetics and pharmacodynamics, especially with regard to optimal dosing to avoid side effects. In this article, we selected and reviewed randomized controlled trials to summarize the pharmacokinetics, antinociceptive effects, anti-hyperalgesic effects, anti-inflammatory effects, side effects, and role of intravenous lidocaine in the management of early postoperative pain. The mechanisms of action of lidocaine are still unclear but there are many theories postulated. Optimal dosing of lidocaine is not known but general consensus indicates that a loading dose of 1-2 mg/kg, followed by 1-2 mg/kg/hr continuous infusion during early postoperative pain control while recovering from anesthesia to achieve therapeutic levels of 0.5-5 mcg/kg clearly improves analgesia in the immediate postoperative period. Although lidocaine was initially studied and proven to have clear analgesic effects following laparoscopic and open abdominal surgeries, it has now been shown to be applicable in different clinical settings perioperatively including following spinal, breast, ENT and other surgeries. It is generally safe, with hypotension, headache and vomiting being the more common side effects. Serious adverse effects include cardiovascular block and arrhythmias, neuro-excitability and hypersensitivity, although the frequency of these are not known.

Association Between Pain Scores and Successful Spinal Cord Stimulator Implantation.

INTRODUCTION: Determining reduction in pain score during spinal cord stimulation (SCS) trial is important prior to permanent SCS implantation. However, this association remains elusive. We investigate the association between post-SCS pain scores and successful permanent SCS implants. MATERIALS AND METHODS: This IRB-approved, retrospective study identified patients who underwent SCS trials and implantation. Predictive modeling with nonparametric regression and margins plot analysis was used to determine the threshold for post-SCS trial pain scores associated with successful permanent SCS implant (defined as >50% pain relief). Nonparametric sensitivity and specificity analysis was performed. p < 0.05 was considered significant. RESULTS: Eighty-eight patients with SCS trials were retrospectively identified (57.95% female, median age 52.5 ± 15.5 years). Of the total cohort, 79% had successful permanent SCS implantation. Post-SCS trial pain scores less than or equal to 4.9 had greater than 50% probability of a successful permanent SCS implant (97.14% sensitivity, 44.44% specificity, ROC = 0.71). Post-SCS trial pain scores between 4 and 7 were associated with a significantly higher probability of a successful SCS implant among patients without spine surgery compared with those with a history of spine surgery. Compared with males, females with pain scores between 5 and 7 had a higher probability of a successful SCS implant. CONCLUSION: Low pain scores after SCS trial are predictive of successful SCS implants with high sensitivity. Males and surgical patients with higher pain scores had a lower probability of successful SCS implant than their counterparts. Larger studies are needed to further elucidate this relationship.

Socioeconomic disparities in the utilization of spine augmentation for patients with osteoporotic fractures: an analysis of National Inpatient Sample from 2011 to 2015.

BACKGROUND CONTENT: Vertebral augmentation procedures are used for treatment of osteoporotic compression fractures. Prior studies have reported disparities in the treatment of patients with osteoporotic vertebral fractures, particularly with regards to the use of vertebroplasty and kyphoplasty. PURPOSE: The purpose of this study is to report updates in racial and health insurance inequalities of spine augmentation procedures in patients with osteoporotic fractures. METHODS: With the use of the National Inpatient Sample, we identified hospitalized patients with osteoporotic fractures between the period of 2011 and 2015. Patients with spine augmentation, defined by the utilization of vertebroplasty and kyphoplasty, were also identified. Our primary outcome was defined as the utilization of spine augmentation procedures across ethnic (white, hispanic, black, and asian/pacific islander) and insurance (self-pay, private insurance, Medicare, and Medicaid) groups. Variables were identified from the NIS database using International Classification of Diseases, Ninth and Tenth diagnosis codes. Univariate and multivariate regression analysis was used for statistical analysis with p value <.05 considered significant. A subgroup analysis was performed across the utilization of kyphoplasty, vertebroplasty, and Medicare coverage. RESULTS: We identified a total of 110,028 patients with a primary diagnosis of vertebral fracture between 2011 and 2015 (mean age: 74.4±13.6 years, 68% women). About 16,237 patients (14.8%) underwent any type of spine augmentation with over 75% of the patients receiving kyphoplasty. Multivariate analysis showed that black patients (odds ratio [OR]=0.64, 95% confidence interval [CI]: 0.58-0.70, p<.001), Hispanic patients (OR=0.79, 95% CI: 0.73-0.86, p<.001), and Asian/Pacific Islander (OR=0.79, 95% CI: 0.70-0.89, p<.001) had significantly lower odds for receiving any spine augmentation compared with white patients. Patients with Medicaid (OR=0.59, 95% CI: 0.53-0.66, p<.001), private insurance (OR=0.90, 95% CI: 0.85-0.96, p=.001), and those who self-pay (OR=0.57, 95% CI: 0.47-0.69, p<.001) had significantly lower odds of spine augmentation compared with those with Medicare. Comparative use of kyphoplasty was not significantly different between white and black patients (OR=0.85, 95% CI: 0.70-1.04, p=.12). However, Hispanic patients (OR=0.84, 95% CI: 0.71-0.99, p=.04) and Asian/Pacific Islander patients (OR=0.73, 95% CI: 0.58-0.92, p=.007) had significantly lower use of kyphoplasty compared with white patients. The comparative use of kyphoplasty among patients receiving spine augmentation was not significantly different across each insurances status when compared with patients with Medicare. CONCLUSIONS: Our study suggests that racial and socioeconomic disparities continue to exist with the utilization of spine augmentation procedures in hospitalized patients with osteoporotic fractures.

Fascia iliaca block, history, technique, and efficacy in clinical practice.

The facsia iliaca block (FIB) is a relatively new regional technique where local anesthetic is delivered within the fascia iliaca region. Indications for a FIB include surgical anesthesia to the lower extremity after knee, femoral shaft, hip surgery, management of cancer pain or pain secondary to inflammatory conditions of the lumbar plexus, as well as treatment of acute pain in the setting of trauma, fracture, or burns. The FIB may be performed using either a loss of resistance technique or an ultrasound (US)-guided technique; however, the use of US has become commonplace and resulted in improved femoral nerve and obturator nerve motor blocks. The main targets of the FIB are the predominant nerves contained in the fascia iliaca compartment (FIC), namely the femoral nerve and the lateral femoral cutaneous nerve. The FIB US guided technique is beneficial to patients and the possibility to perform FIB should be discussed and coordinated with surgical staff appropriately, considering its superiority to general or epidural anesthesia.

Chronic Pain Practices: An Evaluation of Positive and Negative Online Patient Reviews.

BACKGROUND: The role of patient satisfaction continues to play an important role in health care quality measures. The use of online review platforms has been adopted by patients to share their perceptions about the quality of care provided by physicians. Chronic pain practice has unique challenges regarding patient satisfaction. OBJECTIVES: The main goal of this study is to identify the themes associated with positive and negative reviews of chronic pain physicians at publicly available online review platforms. STUDY DESIGN: A retrospective study design. SETTING: We evaluated publicly available online patient-generated reviews of chronic pain physicians from Yelp and Healthgrades. METHODS: This retrospective study evaluated patient-generated reviews of chronic pain physicians from 2 online platforms-Yelp and Healthgrades-between the September 1, 2018 through November 1, 2018. Ninety chronic pain physicians were randomly selected from 4 diverse geographic cities in the United States: New York (NY), Houston (TX), Chicago (IL), and Seattle (WA). Primary outcome was defined as high and low rating scores. Secondary outcome was the proportion of positive and negative attributes (patient, physician, procedure, and administrative attributes) that was associated with high and low rating scores. RESULTS: A total of 1,627 reviews were extracted from 90 physicians evaluated at Yelp and Healthgrades. Of this total review, 1,296 (79.7%) were high scoring and (331) 20.3% were low scoring. Chronic pain providers who were high scoring had positive reviews that consisted of physician attributes (63.5%), administrative attributes (23.4%), and patient attributes (12.2%). The highest proportion of the first 3 physician attributes associated with high ratings were knowledgeable, helpful, and caring. Chronic pain providers who were low scoring had negative reviews that consisted of physician attributes (41.4%), administrative attributes (52.1%), and procedure attributes (5.2%). The highest proportion of the first 3 physician attributes associated with low ratings were disrespectful, unhelpful, and uncaring. LIMITATIONS: First, this study looks at reviews of 4 large cities, thus we may have excluded patient populations with substantially different preferences as health care consumers. Second, it is impossible to confirm the validity of individual reviewers' interactions with the pain management specialist who provided care or validate the identity of the reviewers. Third, it is very difficult, or even impossible, to tell if the rater is a patient or someone posing as a patient, such as an unhappy employee or a business competitor. CONCLUSIONS: Online platforms provide a medium that facilitates immediate communication among patients. These platforms may provide timely data for chronic pain physicians to gain more insight into the quality of care perceived by patients, thereby aiding providers to improve on ways to optimize patient-care experiences and encounters. KEY WORDS: Chronic pain practice, online review, patient review, patient satisfaction.

Depression Trends in Patients with Chronic Pain: An Analysis of the Nationwide Inpatient Sample.

BACKGROUND: Chronic pain remains a major public health issue that affects the lives of many worldwide, including patients with chronic pain. Comorbidities like depression have been associated with decreased quality of sleep, decreased enjoyment of life activities, increased anxiety, and decreased efficacy in treatments among patients with chronic pain. Despite these associations, the trends and demographic characteristics of patients with chronic pain with depression is yet to be investigated. OBJECTIVES: To investigate the trends and demographic characteristics of hospitalized patients with chronic pain with comorbid depression from years 2011 to 2015 in the United States. STUDY DESIGN: This was an observational study. SETTING: Patients were identified from a Healthcare Cost and Utilization Project database called National Inpatient Sample (NIS) documentation. METHODS: Patients were identified from the NIS database using International Classification of Diseases, Ninth and Tenth Revision (ICD-9 and ICD-10) diagnosis codes for chronic pain and comorbid depression from years 2011 to 2015. RESULTS: Between 2011 and 2015, an estimated 9.3 million patients with chronic pain were identified. Of this cohort, 2.2 million patients (22.9%) were diagnosed with comorbid depression. The estimated number of patients with depression varied from 399,865 (22.6%) in 2011 to 421,490 (23.1%) in 2015 (P = 0.13). From 2011 to 2015, there was a significant upward trend of depression among blacks (8.1 ± 0.42% to 9.7 ± 0.27%), patients aged 65 to 84 years (29.0 ± 0.39% to 32.4 ± 0.23%), Medicare insured patients (56.1 ± 0.54% to 58.5 ± 0.29%), Medicaid insured patients (14.7 0.4% to 17.1 ± 0.24%), and patients from zip code areas with lowest annual household income (29.2 ± 1.3% to 32.0 ± 0.59%). Among patients with depression, the adjusted total hospitalization cost increased from $43,584 in 2011 to $49,923 in 2015 (P < 0.001), with average length of hospital stay stable around 5.05 ± 0.02 days. Most patients were discharged home or with self-care compared with short-term facility (57.9 ± 0.14% vs. 2.0 ± 0.03%). LIMITATIONS: Large database research comes with several limitations. The NIS database does not contain variables that can evaluate disease severity such as depression. In addition, the NIS database is highly dependent on the selection and report accuracy of the appropriate diagnostic ICD codes. These estimates could be imprecise from over or underestimation of the number of patients with chronic pain with comorbid depression. CONCLUSIONS: These findings from the present investigation suggest that depression in patients with chronic pain remained stable from 2011 to 2015, with the majority of patients identified as women, white, and ages 45 to 65 years. KEY WORDS: Chronic pain, depression, National Inpatient Sample.

Role of Alpha-2-Microglobulin in the Treatment of Osteoarthritic Knee Pain: a Brief Review of the Literature.

PURPOSE OF REVIEW: Chronic knee pain remains a debilitating condition that remains difficult to manage. The purpose of this review, therefore, is to summarize current understanding of alpha-2-microglobulin in the treatment of osteoarthritic knee pain. Furthermore, we investigate its role in the anti-inflammatory properties of platelet-rich plasma (PRP). RECENT FINDINGS: Alpha-2-microglobulin, a 720-kD protein complex, is an active protease inhibitor with tremendous anti-inflammatory properties in animal models. A growing body of evidence suggests that this complex is the most instrumental factor for cartilage preservation in PRP injections. As an active component of platelet-rich plasma's anti-inflammatory properties, alpha-2-microglobulin has been shown to be an active inhibitor of joint degeneration, cartilage preservation, and improvement in quality of life for patients with knee osteoarthritis compared with a multitude of other modalities.