Intradiscal inflammatory stimulation induces spinal pain behavior and intervertebral disc degeneration in vivo.

Degeneration of the intervertebral disc (IVD) results in a range of symptomatic (i.e., painful) and asymptomatic experiences. Components of the degenerative environment, including structural disruption and inflammatory cytokine production, often correlate with pain severity. However, the role of inflammation in the activation of pain and degenerative changes has been complex to delineate. The most common IVD injury model is puncture; however, it initiates structural damage that is not representative of the natural degenerative cascade. In this study, we utilized in vivo injection of lipopolysaccharide (LPS), a pro-inflammatory stimulus, into rat caudal IVDs using 33G needles to induce inflammatory activation without the physical tissue disruption caused by puncture using larger needles. LPS injection increased gene expression of pro-inflammatory cytokines (Tnfa, Il1b) and macrophage markers (Inos, Arg1), supported by immunostaining of macrophages (CD68, CCR7, Arg1) and systemic changes in blood cytokine and chemokine levels. Disruption of the IVD structural integrity after LPS injection was also evident through changes in histological grading, disc height, and ECM biochemistry. Ultimately, intradiscal inflammatory stimulation led to local mechanical hyperalgesia, demonstrating that pain can be initiated by inflammatory stimulation of the IVD. Gene expression of nociceptive markers (Ngf, Bdnf, Cgrp) and immunostaining for neuron ingrowth (PGP9.5) and sensitization (CGRP) in the IVD were also shown, suggesting a mechanism for the pain exhibited. To our knowledge, this rat IVD injury model is the first to demonstrate local pain behavior resulting from inflammatory stimulation of caudal IVDs. Future studies will examine the mechanistic contributions of inflammation in mediating pain.

Comparative Analysis of 30-Day Readmission, Reoperation, and Morbidity Between Lumbar Disc Arthroplasty Performed in the Inpatient and Outpatient Settings Utilizing the ACS-NSQIP Dataset.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Spine surgery has been increasingly performed in the outpatient setting, providing greater control over cost, efficiency, and resource utilization. However, research evaluating the safety of this trend is limited. The objective of this study is to compare 30-day readmission, reoperation, and morbidity for patients undergoing lumbar disc arthroplasty (LDA) in the inpatient versus outpatient settings. METHODS: Patients who underwent LDA from 2005 to 2018 were identified using the ACS-NSQIP (American College of Surgeons National Surgical Quality Improvement Program) database. Regression was utilized to compare readmission, reoperation, and morbidity between surgical settings, and to evaluate for predictors thereof. RESULTS: We identified 751 patients. There were no significant differences between inpatient and outpatient LDA in rates of readmission, reoperation, or morbidity on univariate or multivariate analyses. There were also no significant differences in rates of specific complications. Inpatient operative time (138 ± 75 minutes) was significantly (P < .001) longer than outpatient operative time (106 ± 43 minutes). In multivariate analysis, diabetes (P < .001, OR = 7.365), baseline dyspnea (P = .039, OR = 6.447), and increased platelet count (P = .048, OR = 1.007) predicted readmission. Diabetes (P = .016, OR = 6.533) and baseline dyspnea (P = .046, OR = 13.814) predicted reoperation. Baseline dyspnea (P = .021, OR = 8.188) and ASA (American Society of Anesthesiologists) class ≥3 (P = .014, OR = 3.515) predicted morbidity. Decreased hematocrit (P = .008) and increased operative time (P = .003) were associated with morbidity in univariate analysis, but not in multivariate analysis. CONCLUSIONS: Readmission, reoperation, and morbidity were statistically similar between surgical setting, indicating that LDA can be safely performed in the outpatient setting. Higher ASA class and specific comorbidities predicted poorer 30-day outcomes. These findings can guide choice of surgical setting given specific patient factors.

To Bundle or Not to Bundle? The Financial Impact of Pathologic Hip Disease on Hip Arthroplasty Episodes of Care.

BACKGROUND: The Comprehensive Care for Joint Replacement model aims to support more efficient care for patients. We examined the impact of patient and surgical characteristics, post-acute care, and clinical outcomes on episode of care (EOC) costs in patients undergoing hip arthroplasty for all diagnoses. METHODS: We retrospectively collected data from a large database of patients undergoing hip arthroplasty for oncologic and nononcologic diagnoses between 2014 and 2017. We compared EOC costs and outcomes between the 2 groups using Student's t-tests. We estimated the association between an oncologic-associated procedure and EOC costs from a multiple regression analysis. RESULTS: There were 2122 total patients included: 1993 in the nononcologic group and 129 in the oncologic group. The length of stay was significantly greater in the oncologic group (7.2 vs 4.2 days, P = .00). In the post-acute period, a greater proportion of oncologic patients was readmitted (29% vs 14%, P = .05) and discharged to skilled nursing (93% vs 51%, P = .00). Index hospitalization costs (mean difference [MD] $1561, P = .05), skilled nursing costs (MD $5932, P = .001), and total EOC costs (MD $20,012, P = .00) were all greater in the oncologic group. Along with increasing age and fracture diagnosis, an oncologic diagnosis is independently associated with greater EOC costs from a multivariate analysis (ß = 16,163 ± 2258, P = .00, r2 = 29%). CONCLUSION: Comprehensive Care for Joint Replacement should incorporate risk adjustment for oncologic disease because hip arthroplasty for an oncologic diagnosis is associated with worse outcomes and greater costs than in the general population.

Academic Metrics Do Not Explain the Underrepresentation of Women in Orthopaedic Training Programs.

BACKGROUND: Among medical specialties, orthopaedic surgery persistently has one of the lowest representations of women in residency programs. This study examined whether differences exist in the academic metrics of the orthopaedic residency applicants and enrolled candidates by sex, which may be contributing to the persistent underrepresentation of women. Differences in enrollment rate in orthopaedic residency programs also were analyzed. We hypothesized that academic metrics were similar for female and male applicants and thus do not explain the underrepresentation of women in training programs. METHODS: Academic data of first-time applicants (n = 9,133) and candidates who enrolled in an orthopaedic residency (n = 6,381) in the U.S. from 2005 to 2014 were reviewed. The United States Medical Licensing Examination (USMLE) Step-1 and Step-2 Clinical Knowledge (CK) scores, Alpha Omega Alpha (AΩA) Honor Medical Society status, number of publications, and volunteer experiences were compared by sex and were analyzed over time. RESULTS: From 2005 to 2014, representation of female applicants increased from 12.6% to 16.0%, corresponding with an increase in the percentage of enrolled female residents (from 12.9% to 16.1%); 70.3% of male and 67.1% of female applicants to orthopaedic residency enrolled as residents (p = 0.082). Mean academic metrics increased significantly over time for applicants and enrolled candidates, irrespective of sex. Comparing by sex, the mean USMLE Step-1 scores of male applicants and enrolled candidates were approximately 2% higher than those of female applicants (p < 0.0001). Volunteer experiences of female applicants and enrolled candidates were 12% higher compared with male applicants (p < 0.0001). There was no significant difference in USMLE Step-2 CK scores, number of publications, or AΩA status by sex. CONCLUSIONS: The enrollment rate of male and female applicants in orthopaedic residencies was similar and did not change during the 10-year study period. The academic metrics of applicants and enrolled candidates have increased significantly. The academic metrics were found to be comparable by sex; the differences in USMLE Step-1 scores and volunteer experiences were small relative to the magnitude of accomplishments that these values represent. The growth rate of the proportion of women in orthopaedic residencies lags other surgical subspecialties but appears to be independent of academic metrics.

Current Trends in Sex, Race, and Ethnic Diversity in Orthopaedic Surgery Residency.

BACKGROUND: The representation of minorities among medical students has increased over the past two decades, but diversity among orthopaedic residents lags behind. This phenomenon has occurred despite a recent focus by the American Academy of Orthopaedic Surgeons on the recruitment of minorities and women. OBJECTIVE: To analyze the impact of recent efforts on diversity in orthopaedic residents in comparison with other surgical specialties from 2006 to 2015. METHODS: Data from the American Association of Medical Colleges on residents in surgical specialty programs in the years 2006 to 2015 were analyzed. Linear regression models were used to estimate trends in diversity among orthopaedic residents and residents in other surgical specialties. A mixed model analysis of variance was used to compare rates of diversification among different specialties over time. RESULTS: Female representation in orthopaedic programs increased from 10.9% to 14.4% between 2006 and 2015. However, the rate of increase was significantly lower compared with other specialties (all P < 0.05) studied, except for urology (P = 0.64). Minority representation in orthopaedics averaged 25.6% over the 10-year period. Residents of Hispanic origin in orthopaedic programs increased (P = 0.0003) but decreased for Native Hawaiian/Pacific Islander (P < 0.0001). During the same period, white representation increased (P = 0.004). No significant changes were found in African Americans or Asian American representation. Diversity decreased among orthopaedic residents over the period studied (P = 0.004). CONCLUSIONS: Recruitment efforts have not reversed the sex, racial, and ethnic disparities in orthopaedic residents. Orthopaedics has the lowest representation of women and minorities among residencies studied. The rate of increase in women lags behind all surgical subspecialties, except for urology.

Underrepresented Minority Applicants Are Competitive for Orthopaedic Surgery Residency Programs, but Enter Residency at Lower Rates.

INTRODUCTION: Orthopaedic surgery residency programs have the lowest representation of ethnic/racial minorities compared with other specialties. This study compared orthopaedic residency enrollment rates and academic metrics of applicants and matriculated residents by race/ethnicity. METHODS: Data on applicants from US medical schools for orthopaedic residency and residents were analyzed from 2005 to 2014 and compared between race/ethnic groups (White, Asian, Black, Hispanic, and Other). RESULTS: Minority applicants comprised 29% of applicants and 25% of enrolled candidates. Sixty-one percent of minority applicants were accepted into an orthopaedic residency versus 73% of White applicants (P < 0.0001). White and Asian applicants and residents had higher USMLE Step 1. White applicants and matriculated candidates had higher Step 2 Clinical Knowledge scores and higher odds of Alpha Omega Alpha membership compared with Black, Hispanic, and Other groups. Publication counts were similar in all applicant groups, although Hispanic residents had significantly more publications. Black applicants had more volunteer experiences. CONCLUSIONS: In orthopaedic surgery residency, minority applicants enrolled at a lower rate than White and Asian applicants. The emphasis on USMLE test scores and Alpha Omega Alpha membership may contribute to the lower enrollment rate of minority applicants. Other factors such as conscious or unconscious bias, which may contribute, were not evaluated in this study.

Evaluation of Sex, Ethnic, and Racial Diversity Across US ACGME-Accredited Orthopedic Subspecialty Fellowship Programs.

In recent years, there has been an increasing trend toward subspecialization in orthopedic surgery via fellowships. This study sought to characterize sex, ethnic, and racial representation within each fellowship program and to examine their changes over time to identify trends and/or gaps. Demographic data were obtained from the National Graduate Medical Education Census. Diversity was assessed using proportions of minority and female trainees. The trends in racial, ethnic, and sex diversity from 2006 to 2015 for orthopedics as a whole and within each subspecialty were analyzed. Of 3722 orthopedic fellows, 2551 identified as white (68.5%), 648 as Asian (17.4%), 175 as Hispanic (4.7%), 161 as black (4.3%), 8 as Native Hawaiian/Pacific Islander (0.21%), and 3 as American Indian/Alaskan Native (0.08%). Further, 479 identified as female (12.9%). Racial and ethnic minority representation among orthopedic fellows did not increase over time. Female representation did increase proportionally with female residents. Asian fellows preferred reconstructive adult and spine, whereas white fellows preferred sports medicine, hand surgery, and trauma. Female fellows preferred pediatrics, hand surgery, and musculoskeletal oncology. Although sex diversity among orthopedic fellows has increased in the past 10 years, racial and ethnic minority representation lacked similar growth. Asian and female fellows preferred specific subspecialties over others. These data are presented as an initial step in determining factors that attract minority groups to different orthopedic subspecialties. Further research should define specific factors and identify ways to increase minority distribution among fellowship programs. [Orthopedics. 2018; 41(5):282-288.].

Iatrogenic Obturator Hip Dislocation with Intrapelvic Migration.

Obturator hip dislocations are rare, typically resulting from high-energy trauma in native hips. These types of dislocations are treated with closed reduction under sedation. Open reduction and internal fixation may be performed in the presence of associated fractures. Still rarer are obturator hip dislocations that penetrate through the obturator foramen itself. These types of dislocations have only been reported three other times in the literature, all within native hips. To date, there have been no reports of foraminal obturator dislocations after total hip arthroplasty. We report of the first periprosthetic foraminal obturator hip dislocation, which was caused iatrogenically during attempts at closed reduction of a posterior hip dislocation in the setting of a chronic greater trochanter fracture. Altered joint biomechanics stemming from a weak hip abductor mechanism rendered the patient vulnerable to this specific dislocation subtype, which ultimately required open surgical intervention. An early assessment and identification of this dislocation prevented excessive closed reduction maneuvers, which otherwise could have had detrimental consequences including damage to vital intrapelvic structures. This case report raises awareness to this very rare, yet potential complication after total hip arthroplasty.

The effect of severity of disease on cost burden of 30-day readmissions following total joint arthroplasty (TJA).

In order to control the unsustainable rise in healthcare costs the Federal Government is experimenting with the bundled payment model for total joint arthroplasty (TJA). In this risk sharing model, providers are given one payment, which covers the costs of the TJA, as well as any additional medical costs related to the procedure for up to 90 days. The amount and severity of comorbid conditions strongly influence readmission rates and costs of readmissions in TJA patients. We identified 2026 TJA patients from our database with APR-DRG SOI data for use in this study. Both the costs of readmission and the readmission rate tended to increase as severity of illness increased. The readmission burden also increased as SOI increased, but increased most markedly in the extreme SOI patients.

Meniscal repair.

Historically, treatment of meniscus tears consisted of complete meniscectomy. Over the past few decades, however, the long-term morbidities of meniscal removal, namely the early development of knee osteoarthritis, have become apparent. Thus, management of meniscal tears has trended toward meniscal preservation. Recent technological advances have made repairs of the meniscus easier and stronger. In addition, adjunctive therapies used to enhance the healing process have advanced greatly in the past few years. Today, with increased understanding of the impact of meniscal loss and the principles of meniscal repair and healing, meniscal preservation is viewed as an increasingly realistic and important goal in the management of meniscus tears.