Duration of Back Pain Symptoms and Its Relationship to Paralumbar Muscle Volume.

OBJECTIVE: Paralumbar muscle volume has been indicated as an important factor for patients reporting back pain. Our goal was to determine if there is a statistically significant relationship between the duration of patients' back pain symptoms (>12 weeks or ≤12 weeks) and paralumbar muscle volume. METHODS: In this retrospective cohort study, paralumbar muscles on axial T2-weighted lumbar magnetic resonance images were outlined using ImageJ to determine the paralumbar cross-sectional area (PL-CSA) and lumbar indentation value (LIV) at the center of disc spaces from L1 to L5. The Goutallier classification was determined by the primary author. Quantile regression was performed to compare the PL-CSA, PL-CSA normalized by body mass index, and LIV between the 2 cohorts. Cohort A consisted of patients reporting symptoms ≤12 weeks, and cohort B included patients with symptoms >12 weeks. Negative binomial regression was used to compare Goutallier class. RESULTS: A total of 551 patients operated on by a single surgeon with lumbar magnetic resonance imaging within the past 12 months and recorded duration of symptoms were included. Cohort A consisted of 229 patients (41.6%), and cohort B included 322 patients (58.4%). Statistical significance was not found at any lumbar level for PL-CSA, PL-CSA normalized by body mass index, Goutallier class, and LIV. CONCLUSIONS: Our results suggest that duration of symptoms may not be an accurate indicator for lumbar muscle volume. These novel findings are clinically valuable because lumbar muscle volume has been shown to be a marker for recovery. With this information, patients previously believed to be inoperable because of long-standing symptoms can be reevaluated.

Immune cell profiles of patients with interstitial cystitis/bladder pain syndrome.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a disorder characterized by bladder pain upon filling which severely affects quality of life. Clinical presentation can vary. Local inflammatory events typify the clinical presentation of IC/BPS patients with Hunner lesions (IC/BPS-HL). It has previously been proposed that B cells are more prevalent in HL, but understanding their exact role in this environment requires a more complete immunological profile of HL. We characterized immunological dysfunction specifically in HL using immunohistochemistry. We detected significantly more plasma cells (50× increase, p < 0.0001), B cells (28× increase, p < 0.0001), T cells (3× increase, p < 0.0001), monocytes/macrophages (6× increase, p < 0.0001), granulocytes (4× increase, p < 0.0001), and natural killer cells (2× increase, p = 0.0249) in IC/BPS patients with HL than in unaffected controls (UC). Patients with IC/BPS-HL also had significantly elevated urinary levels of IL-6 (p = 0.0054), TNF-α (p = 0.0064) and IL-13 (p = 0.0304) compared to patients with IC/BPS without HL (IC/BPS-NHL). In contrast, IL-12p70 levels were significantly lower in the patients with HL than in those without these lesions (p = 0.0422). Different cytokines were elevated in the urine of IC/BPS patients with and without HL, indicating that different disease processes are active in IC/BPS patients with and without HL. Elevated levels of CD138+, CD20+, and CD3+ cells in HL are consistent B and T-cell involvement in disease processes within HL.

Increased In-Hospital Lengths of Stay, Readmission Rates, Complications, and Costs in Patients Who Have Depressive Disorders Following Primary Total Hip Arthroplasty.

INTRODUCTION: Recent studies have shown the prevalence of depressive disorders has increased within the United States. Studies investigating the impact of depressive disorders following primary THA are limited. Therefore, the purpose of this study was to determine whether patients with depressive disorders have higher rates of: 1) in-hospital lengths of stay (LOS); 2) readmission rates; 3) medical complications; and 4) implant-related complications. MATERIALS AND METHODS: A retrospective query of the Humana claims database was performed. Patients undergoing primary THA with a history of depressive disorders were identified by International Classification of Disease, Ninth Revision (ICD-9), and Current Procedural Terminology (CPT) codes. Study group patients were matched to controls in a 1:5 ratio by age, sex, and comorbidities. The query yielded 67,245 patients with (n=11,255) and without (n=55,990) depressive disorders. Welch's t-tests were used to test for significance in LOS between the cohorts; whereas, logistics regression analyses were used for complications and readmissions. A p-value less than 0.003 was statistically significant. RESULTS: Patients with depressive disorders undergoing primary THA had significantly longer in-hospital LOS (6.59 days vs. 2.96 days, p <0.0001). Additionally, patients with depressive disorders had higher incidence and odds of readmission rates (46.02 vs. 35.43%; OR: 1.55, p <0.0001), medical complications (7.05 vs. 1.84%; OR: 4.04, p <0.0001), and implant-related complications (5.76 vs. 2.75%; OR: 2.16, p <0.0001) compared to patients without depressive disorders. CONCLUSION: After matching age, sex, and medical comorbidities, the results of the study demonstrate patients with depressive disorders have longer in-hospital LOS and increased rates of complications and readmission rates. The study is useful as it can allow orthopedic surgeons to properly counsel these patients of the potential complications which may arise following their procedure.

An Economic Evaluation of Over 200,000 Revision Total Hip Arthroplasties: Is the Current Model Sustainable?

INTRODUCTION: Revision total hip arthroplasties (rTHAs) are typically more complicated than primaries and may have a greater economic burden. To date, the current economic model supporting these procedures has not been evaluated. Therefore, the purpose of this study was to determine the 10-year temporal changes in charges, reimbursement rates, and net losses in patients undergoing an rTHA utilizing a large, nationwide database. MATERIALS AND METHODS: A query was performed from 2005 to 2014 to identify patients who underwent rTHA. Analyzed outcomes included trends in costs of care, reimbursement rates, and net losses per annum within the last 10 years. Charges are defined as those by the provider to the insurance company, whereas, reimbursements were those payments received from the insurance company. Net losses were calculated as the difference in charges from reimbursement rates. RESULTS: Total charges increased from $1,119,725,881 in 2005 to $2,066,842,547 in 2014. Total reimbursements increased from $287,461,852 in 2005 to $478,430,569 in 2014. Per patient charges increased 67.4% from 2005 to 2014 and from $51,963.18 in 2005 to $86,791.07 in 2014. There was an increase in reimbursement per patient of 61.4% from $12,450.70 in 2005 to $20,090.31 in 2014. Net losses increased 68.80%, from $39,512.48 to $66,700.76 from 2005 to 2014. CONCLUSION: This study indicates substantial increases in charges and reimbursements over a 10-year period for patients undergoing rTHA. However, reimbursement increased at a lower rate than that of charges, resulting in major net losses. This study highlights the need to reevaluate the economic models behind rTHA for longer-term sustainment.

Outcomes of Cementless-Backed Patellar Components.

Because of the early follow-up positive outcomes with cementless fixation, continued evaluations need to be performed to ensure longer-term efficacy. Additionally, although many studies report on the results of femoral and tibial component fixation, few studies report specifically on patellar outcomes. Therefore, the purpose of this study was to report on the: (1) implant survivorship; (2) complications; and (3) radiographic outcomes in a large cohort of patients who received cementless total knee arthroplasties (TKAs), with particular attention to the patellar component. A total of 261 patients who underwent cementless TKA by a single, high-volume academic surgeon were studied. Patients had a mean age of 66 years and were distributed between 192 women (74%) and 69 men. All patients received the same cementless tibial, femoral, and patellar components. Mean follow-up period was 4.5 years (range, 4-5 years). Primary outcomes evaluated included all postoperative complications, with particular emphasis on the patellar component. Only one patellar loosened leading to a patellar aseptic loosening rate of 0.3% (1 of 261). The one patellar loosening was the component being dislodged after a manipulation under anesthesia (MUA) at 6 weeks. This was revised to a cemented component and the patient is doing well 4 years later. A second patient experienced a patellar tendon rupture, later surgically repaired. Another patient sustained a patella fracture that was managed nonoperatively. The fracture healed by 1 year and the patient continued to have an otherwise successful outcome, now at 2 years follow-up. No progressive radiolucencies, subsidence, or changes in initial postoperative axial alignment were observed at final follow-up. The results from this study highlight a 98% success rate at mean 4.5 years follow-up in a large cohort of patients with a diverse spread of demographic details. Specific to the patella, only one patient experienced an adverse event, which was managed nonoperatively. Therefore, based on this data, patellar fixation in cementless TKA can be considered a safe technique.

Computer-Assisted Navigation in Total Knee Arthroplasty.

Manual total knee arthroplasty (TKA) has successfully treated end-stage knee osteoarthritis for several years. However, recent technological advancements have enabled surgeons to perform TKA with more accuracy and precision. Aligning the femoral and tibial components perpendicular to the mechanical axes of the femur and tibia is a fundamental principle for restoring knee kinematics and soft-tissue balance. Computer-assisted robotic TKA has proven its ability to fine tune lower leg alignment, component position, and soft-tissue balancing. Furthermore, robotic-assisted TKA (RATKA) offers the additional benefit of improving soft-tissue protection compared to manual techniques. Numerous systems have been developed in the advancement of technology in computer processing, and the number of robotic surgical systems is increasing as well. The three main categories of navigation systems can be classified as: image-based console navigation, imageless console navigation, and accelerometer-based handheld navigation systems. The purpose of this review was to describe emerging technologies for TKA. Specifically, we outline the available literature pertaining to each system with regards to their: (1) accuracy and precision of component alignment; (2) soft-tissue protection; (3) postoperative outcomes; and (4) other reported outcomes such as costs.

Crosstalk between the immune system and neural pathways in interstitial cystitis/bladder pain syndrome.

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a condition causing intense pelvic pain and urinary symptoms. While it is thought to affect millions of people and significantly impair quality of life, difficulty with diagnosis and a lack of reliably effective treatment options leave much progress to be made in managing this condition. We describe what is currently known about the immunological and neurological basis of this disease, focusing on the interactions between the immune and nervous system. Evidence for immune involvement in IC/BPS comes from its high co-occurrence with known autoimmune diseases, altered cytokine profiles, and immune cell infiltration in patients. These cytokines have the ability to cross-talk with the nervous system via NGF signaling, resulting in hyper-sensitization of pain receptors, causing them to release substance P and creating a positive feedback loop of neuroinflammation. While it seems that the crosstalk between the immune and nervous system in IC is understood, much of the information comes from studying other diseases or from animal models, and it remains to be confirmed in patients with the disease. Identifying biomarkers and confirming the mechanism of IC/BPS are ultimately important for selecting drug targets and for improving the lives of patients with this disease.