Trends in Deep Vein Thrombosis Prophylaxis and Deep Vein Thrombosis Rates After Total Hip and Knee Arthroplasty.

INTRODUCTION: Patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) are at high risk of deep vein thrombosis (DVT) postoperatively, necessitating the use of prophylaxis medications. This investigation used a large claims database to evaluate trends in postoperative DVT prophylaxis and rates of DVT within 6 months after THA or TKA. METHODS: Truven Health MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases were reviewed from 2004 to 2013 for patients who underwent THA or TKA. Data were collected on patient age, sex, Charlson Comorbidity Index, and hypercoagulability diagnoses. Postoperative medication claims were reviewed for prescribed aspirin, warfarin, enoxaparin, fondaparinux, rivaroxaban, and dabigatran. RESULTS: A total of 369,483 patients were included in the analysis, of which 239,949 patients had prescription medication claims. Warfarin was the most commonly prescribed anticoagulant. Patients with a hypercoagulable diagnosis had markedly more DVTs within 6 months after THA or TKA. More patients with a hypercoagulable diagnosis were treated with warfarin or lovenox than other types of anticoagulants. A multivariate regression analysis was performed, showing that patients prescribed aspirin, fondaparinux, and rivaroxaban were markedly less likely than those prescribed warfarin or enoxaparin to have a DVT within 6 months after THA or TKA. CONCLUSION: After THA and TKA, warfarin is the most commonly prescribed prophylaxis. Patients with hypercoagulability diagnoses are at a higher risk of postoperative DVT. The likelihood of DVT within 6 months of THA and TKA was markedly higher in patients treated with warfarin and lovenox and markedly lower in those treated with aspirin, fondaparinux, and rivaroxaban. LEVEL OF EVIDENCE: Level III.

Preoperative Opioid Use Is Associated with Higher Readmission and Revision Rates in Total Knee and Total Hip Arthroplasty.

BACKGROUND: Prescription opioid use is epidemic in the U.S. Recently, an association was demonstrated between preoperative opioid use and increased health-care utilization following abdominal surgeries. Given that primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) are 2 of the most common surgical procedures in the U.S., we examined the association of preoperative opioid use with 30-day readmission and early revision rates. METHODS: We reviewed 2003 to 2014 data from 2 Truven Health MarketScan databases (commercial insurance and Medicare plus commercial supplemental insurance). Subjects were included if they had a Current Procedural Terminology (CPT) code for primary TKA or THA and were continuously enrolled in the database for at least 6 months prior to the index procedure. Preoperative opioid prescriptions were identified using National Drug Codes (NDCs). Rates of 30-day readmissions and revision arthroplasty were identified and compared among patients with stratified durations of preoperative opioid use in the 6 months preceding TKA or THA. RESULTS: The study included 324,154 patients in the 1-year follow-up group and 159,822 patients in the 3-year follow-up group. Opioid-naive TKA patients had a lower revision rate than did those with >60 days of preoperative opioid use (1-year cohort: 1.07% compared with 2.14%, p < 0.001; 3-year cohort: 2.58% compared with 5.00%, p < 0.001). A similar trend was noted among THA patients (1-year: 0.38% compared with 1.10%, p < 0.001; 3-year: 1.24% compared with 2.99%, p < 0.001). These trends persisted after adjusting for age, sex, and Charlson Comorbidity Index (CCI). The 30-day readmission rate after TKA or THA was significantly lower for patients with no preoperative opioid use compared with those with >60 days of preoperative opioid use (TKA: 4.82% compared with 6.17%, p < 0.001; THA: 3.71% compared with 5.85%, p < 0.001). Again, this association persisted after adjusting for age, sex, and CCI. CONCLUSIONS: Preoperative opioid use was associated with significantly increased risk of early revision and significantly increased risk of 30-day readmission after TKA and THA. This study illustrates the increased risk of poor outcomes and increased postoperative health-care utilization for patients with long-term opioid use prior to THA and TKA. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pediatric Chondrosarcoma of the Sternum Resected with Thorascopic Assistance.

BACKGROUND: Chondrosarcomas are a heterogeneous group of malignant neoplasms that arise from bones, cartilage or other soft tissues that produce cartilage and are commonly seen in the middle decades of life. Despite being the most common primary bone sarcoma in adults, chondrosacromas are rare in pediatric patients. CASE REPORT: We report the case of a six-year-old child with a painless enlarging sternal mass of which biopsy was consistent with low-grade surface chondrosarcoma. This is the first reported case of a chest wall chondrosarcoma in a young child. This unusual location in a young patient presented challenges to treatment. Resection of the manubrium was performed by a multidisciplinary team of orthopaedic oncology and pediatric general surgery. The patient underwent a wide resection of the sternal mass from an anterior approach performed by the orthopaedic oncology team using an oscillating saw under video-assisted thoracoscopic surgery to ensure adequate mass resection without injury to nearby structures. The patient was followed with quarterly physical exams and radiographs for 18 months postoperatively and did not have any pain or evidence of recurrence. CONCLUSION: Clinicians should consider utilizing multidisciplinary approaches to treat patients with chondrosarcomas of the chest wall.

Hyaluronic Acid Injections for Treatment of Advanced Osteoarthritis of the Knee: Utilization and Cost in a National Population Sample.

BACKGROUND: The prevalence of knee osteoarthritis is increasing in the aging U.S. POPULATION: The efficacy and cost-effectiveness of the use of hyaluronic acid (HA) injections for the treatment of knee osteoarthritis are debated. In this study, we assessed the utilization and costs of HA injections in the 12 months preceding total knee arthroplasty (TKA) and evaluated the usage of HA injections in end-stage knee osteoarthritis management in relation to other treatments. METHODS: MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases (Truven Health Analytics) were reviewed to identify patients who underwent TKA from 2005 to 2012. The utilization of patient-specific osteoarthritis-related health care (including medications, corticosteroid injections, HA injections, imaging, and office visits) and payment information were analyzed for the 12 months preceding TKA. RESULTS: A total of 244,059 patients met the inclusion criteria. Of those, 35,935 (14.7%) had ≥1 HA injection in the 12 months preceding TKA. HA injections were responsible for 16.4% of all knee osteoarthritis-related payments, trailing only imaging studies (18.2%), and HA injections accounted for 25.2% of treatment-specific payments, a rate that was higher than that of any other treatment. Patients receiving HA injections were significantly more likely to receive additional knee osteoarthritis-related treatments compared with patients who did not receive HA injections. CONCLUSIONS: Despite numerous studies questioning the efficacy and cost-effectiveness of HA injections for osteoarthritis of the knee, HA injections are still utilized for a substantial percentage of patients. Given the paucity of data supporting the effectiveness of HA injections and the current cost-conscious health-care climate, decreasing their use among patients with end-stage knee osteoarthritis may represent a substantial cost reduction that likely does not adversely impact the quality of care.

Gender Disparities in Osteoarthritis-Related Health Care Utilization Before Total Knee Arthroplasty.

OBJECTIVES: Women older than 50 years have higher prevalence of knee osteoarthritis (OA) and experience greater functional disability than men. No studies have examined large populations to identify knee OA-related health care utilization differences. The purpose of this investigation was to evaluate gender differences in the utilization of OA-related health care resources in the 12 months preceding total knee arthroplasty (TKA). METHODS: Truven Health MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefit databases were reviewed from 2005 to 2012. Subjects were included if they underwent TKA, had associated diagnosis of lower leg OA, and were continuously in the database for 12 months preceding TKA. Patient-specific OA-related health care utilization was identified. Multivariate logistic regression analysis controlling for age, region, and Charlson Comorbidity Index was performed to isolate the influence of gender. RESULTS: A total of 244,059 patients with a mean age of 64.8 years consisting of 61.2% women were included. Multivariate logistic regression adjusted odds ratios showed that when compared to men, women were 30%, 20%, 31%, 18%, 19%, 29%, and 39%, more likely to receive a narcotic analgesic, nonnarcotic analgesics, corticosteroid injection, hyaluronic acid injection, knee magnetic resonance imaging, a physical therapy evaluation, and occupational therapy evaluation in the 12 months preceding TKA, respectively. CONCLUSION: Women have a significantly higher utilization of knee OA-related health care in the 12 months preceding TKA. Although the precise cause for this discrepancy in care cannot be determined from this study, it highlights a potential bias in management of advanced knee OA and directions for further investigation.

Anti-Osteoporotic Therapy After Fragility Fracture Lowers Rate of Subsequent Fracture: Analysis of a Large Population Sample.

BACKGROUND: This investigation assessed the effectiveness of initiating anti-osteoporotic therapy after a fragility fracture in preventing subsequent fractures. METHODS: The Truven Health MarketScan databases, which contain de-identified, integrated, person-specific claim data, were queried from 2003 to 2012. The study population included individuals fifty years of age or older who sustained a fragility fracture, defined as any fracture of the wrist, proximal part of the humerus, hip, or vertebra, and had three years of continuous enrollment following fracture. Patients were stratified into either an anti-osteoporotic therapy group or a no-treatment group. Subsequent fracture was defined as a fragility fracture occurring more than ninety days following the index fracture. Subjects were followed for three years. Unadjusted and age and sex-adjusted odds ratios for subsequent fracture were calculated for both groups. RESULTS: This investigation included 31,069 subjects, of whom 10.6% were treated with anti-osteoporotic therapy following the index fracture. The anti-osteoporotic therapy group was older and had a greater proportion of female patients compared with the no-treatment group. The three-year subsequent fracture rates were 7.5% in the anti-osteoporotic therapy group and 9.7% in the no-treatment group. Unadjusted odds ratios for subsequent fracture showed that the anti-osteoporotic therapy group experienced a risk reduction of 33% after an index wrist fracture, 48% after an index proximal humeral fracture, 28% after an index hip fracture, 20% after an index vertebral fracture, and 25% after all fractures combined. Age and sex-adjusted odds ratios showed that the anti-osteoporotic therapy group experienced a reduction in risk of 50% after an index wrist fracture, 52% after an index proximal humeral fracture, 34% after an index hip fracture, 43% after an index vertebral fracture, and 40% after all fractures combined. The number needed to treat to prevent a subsequent fragility fracture was twenty-eight after an index wrist fracture, twenty after an index proximal humeral fracture, twenty-six after an index hip fracture, twenty-five after an index vertebral fracture, and twenty-seven after all fractures combined. CONCLUSIONS: Treatment with anti-osteoporotic therapy after a fragility fracture leads to a 40% decrease in the three-year risk of subsequent fracture, when adjusted for age and sex. Initiation of anti-osteoporotic therapy following a fragility fracture can prevent a subsequent fracture over the following three years in approximately one of every twenty-seven patients treated.

Predictors of range of motion in patients undergoing manipulation after TKA.

BACKGROUND: Knee stiffness or limited range of motion (ROM) after total knee arthroplasty (TKA) may compromise patient function. Patients with stiffness are usually managed with manipulation under anesthesia (MUA) to improve ROM. However, the final ROM obtained is multifactorial and may depend on factors such as comorbidities, implant type, or the timing of MUA. QUESTIONS/PURPOSES: We asked whether diabetes mellitus, implant type, and the interval between TKA and MUA influenced post-MUA ROM. METHODS: From a group of 2462 patients with 3224 TKAs performed between 1999 and 2007 we retrospectively reviewed 96 patients with 119 TKAs (4.3%) who underwent MUA. We determined the presence of diabetes mellitus, implant type, and the interval between TKA and MUA. RESULTS: The average increase in ROM after MUA was 34°. Patients with diabetes mellitus experienced lower final ROM after MUA (87.5° versus 100.3°) as did patients with cruciate-retaining (CR) prostheses versus posterior-stabilized (92.3° versus 101.6°). The interval between TKA and MUA inversely correlated with final ROM with a decrease after 75 days. CONCLUSIONS: Most patients experience improvements in ROM after MUA. Patients with diabetes mellitus or CR prostheses are at risk for lower final ROM after MUA. Manipulation within 75 days of TKA is associated with better ROM.

Blood-brain barrier damage, but not parenchymal white blood cells, is a hallmark of seizure activity.

It has long been held that chronic seizures cause blood-brain barrier (BBB) damage. Recent studies have also demonstrated that BBB damage triggers seizures. We have used the BBB osmotic disruption procedure (BBBD) to examine the correlation between BBB opening, pattern of white blood cell (WBCs) entry into the brain and seizure occurrence. These findings were compared to results from resected epileptic brain tissue from temporal lobe epilepsy (TLE) patients. We confirmed that a successful BBB osmotic opening (BBBD) leads to the occurrence of acute epileptiform discharges. Electroencephalography (EEG) and time-joint frequency analysis reveal EEG slowing followed by an increase in the 10-20Hz frequency range. Using green fluorescent protein (GFP)-labeled WBCs (GFP-WBCs) suspended in Evans Blue we found that, at time of BBB-induced epileptiform discharges, WBCs populated the perivascular space of a leaky BBB. Similar results were obtained at time of pilocarpine seizure. No frank WBCs extravasation in the brain parenchyma was observed. In TLE brain specimens, CD45-positive leukocytes were detected only in the vascular and perivascular spaces while albumin and IgG extravasates were parenchymal. The pattern was similar to those observed in rats. Our data suggest that neither acute-induced nor chronic seizures correlate with WBC brain parenchymal migration while albumin and IgG brain leakage is a hallmark of acute and chronic seizures.

Participation of Kv1 channels in control of membrane excitability and burst generation in mesencephalic V neurons.

The function and biophysical properties of low threshold Kv1 current in control of membrane resonance, subthreshold oscillations, and bursting in mesencephalic V neurons (Mes V) were examined in rat brain stem slices (P8-P12) using whole cell current and voltage patch-clamp methods. alpha-dendrotoxin application, a toxin with high specificity for Kv1.1, 1.2, and 1.6 channels, showed the presence of a low-threshold K(+) current that activated rapidly around -50 mV and was relatively noninactivating over a 1-s period and had a V(1/2)max of -36.2 mV. Other toxins, specific for individual channels containing either Kv 1.1, 1.2, or 1.3 alpha-subunits, were applied individually, or in combination, and showed that Kv1 channels are heteromeric, composed of combinations of subunits. In current-clamp mode, toxin application transformed the high-frequency resonant properties of the membrane into a low-pass filter and concomitantly reduced the frequency of the subthreshold membrane oscillations. During this period, rhythmical bursting was transformed into low-frequency tonic discharge. Interestingly, in a subset of neurons that did not show bursting, low doses of alpha-dendrotoxin (alpha-DTX) sufficient to block 50% of the low threshold Kv1 channels induced bursting and increased the resonant peak impedance and subthreshold oscillations, which was replicated with computer simulation. This suggests that a critical balance between inward and outward currents is necessary for bursting. This was replicated with computer simulation. Single cell RT-PCR and immunohistochemical methods confirmed the presence of Kv1.1, 1.2, and 1.6 alpha-subunits in Mes V neurons. These data indicate that low threshold Kv1 channels are responsible for membrane resonance, contribute to subthreshold oscillations, and are critical for burst generation.