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.

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.

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.