Incidence,Risk Factors,and Costs for Hospital Returns After Total Joint Arthroplasties

Background

Unplanned hospital returns after total joint arthroplasty (TJA) reduce any cost savings in a bundled reimbursement model. We examine the incidence, risk factors, and costs for unplanned emergency department (ED) visits and readmissions within 30 days of index TJA.

Metal-on-Metal Compared With Metal-on-Polyethylene: The Effect on Trunnion Corrosion in Total Hip Arthroplasty

Background

Trunnion tribocorrosion in total hip arthroplasties is concerning, but retrieval studies often are subjective or lack comparison groups. Quantitative comparisons of clinically relevant implants are required. The purpose of this investigation was to evaluate material loss in metal-on-metal (MoM) and metal-on-polyethylene (MoP) total hip articulations while controlling for trunnion design and head size.

Factors affecting perioperative blood loss and transfusion rates in primary total joint arthroplasty: a prospective analysis of 1642 patients

Background

In recent years, the use of low molecular weight heparins such as dalteparin has become attractive because of their ease of administration and superiority in preventing venous thromboembolism (VTE) compared with traditional agents. The primary purpose of our study was to evaluate the impact of dalteparin use on blood loss and transfusion rates in patients undergoing primary total joint arthroplasty. We also evaluated the effect of patient sex, releasing the tourniquet in knee arthroplasty and the turnover of house staff.

Methods

Using our hospital transfusion database, we prospectively studied the mean reduction in hemoglobin and transfusion rates of 1642 consecutive patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) between January 2004 and December 2005. In 2004, warfarin was used exclusively for VTE prevention; however, in 2005, following the release of the 2004 American College of Chest Physicians’ guidelines, our centre began using dalteparin for VTE prophylaxis. We analyzed the impact of dalteparin use and the effect of patient sex, tourniquet release in TKA and house staff turnover months on blood loss and transfusion rates.

Results

The use of dalteparin for postoperative VTE prevention in patients undergoing THA and TKA in 2005 was associated with a significantly greater mean reduction in hemoglobin compared with warfarin use in 2004 (p = 0.014 for patients undergoing THA, p < 0.001 for patients undergoing TKA). The use of dalteparin in 2005 was not associated with a significant increase in allogeneic blood transfusions compared with the use of warfarin in 2004, except in women (p < 0.001). Although we observed no significant differences in mean reduction in hemoglobin between men and women undergoing THA, women undergoing THA had significantly higher transfusion rates regardless of the method of VTE prophylaxis (p = 0.037 for warfarin, p < 0.001 for dalteparin). Intraoperative tourniquet release in patients undergoing TKA was associated with a significantly lower mean reduction in hemoglobin than release after wound closure (p = 0.005). Although house staff turnover months were associated with a significantly greater mean reduction in hemoglobin levels than non-turnover months (p = 0.039), these months were not associated with a significant increase in allogeneic blood transfusions (p = 0.59).

Conclusion

Low molecular weight heparins such as dalteparin are the most common form of VTE prophylaxis in Canada. Our results suggest that dalteparin use, timing of tourniquet release and house staff turnover can all influence transfusion rates and/or blood loss in patients undergoing primary total joint arthroplasty. This study also emphasizes that women undergoing THA are at particularly high risk for blood transfusion.     

Versatility of Hemisternotomy for Cardiac Surgery

Abstract   Background: Hemisternotomy has been suggested as a way to reduce morbidity by limiting the invasiveness of surgical interventions but it is often limited to aortic valve disease. This study reviews the experience of one center employing hemisternotomy and compares patient outcomes, both in-hospital and post-discharge, with a matched group of full sternotomy patients. Methods: Propensity scores were used to match all hemisternotomy valve cases (Hemi) to full sternotomy valve cases (Full) (1:2). An in-hospital composite outcome (COMP) was defined as mortality, stroke, deep sternal wound infection, sepsis, or return to operating room (OR) for bleeding or valve dysfunction. Provincial administrative health databases were used to determine freedom from mortality and hospital readmission for cardiac cause. Results: During the study period, 70 patients received hemisternotomy for various cardiac surgical interventions with only 38 patients undergoing isolated aortic valve replacement. Examining valve surgery exclusively, 65 Hemi were matched to 130 Full. In-hospital complications were low in both groups, with 1.0% mortality and a non-significant trend toward COMP in the Full group (Hemi = 4.6%; Full = 8.5%; p = 0.39). Ventilation time was significantly decreased in Hemi (median four vs. six hours; p = 0.002). At two years follow-up, survival was excellent for both (Hemi = 95.0%; Full = 93.6%) and freedom from cardiac morbidity (Hemi = 76.8%, Full = 73.2%) was comparable. Conclusion: Hemisternotomy appears to be a safe, effective, and versatile alternative for many cardiac surgical interventions. With a median follow-up of four years, this study represents the longest cardiac morbidity follow-up for hemisternotomy patients. However, we were unable to conclusively show a morbidity benefit with this incision.     

Prolonged skin allograft survival in Scid mice reconstituted with isogeneic bone marrow stem cell antigen-1-positive cells and thymus tissue

INTRODUCTION: Many studies indicate that tolerance induction is much more dependent on the maturation status of lymphocytes than the age of the animal. We hypothesized that direct persistent contact of bone marrow stem cells with graft alloantigen will result in tolerance to that antigen in the adult animal. MATERIAL AND METHODS: Severe combined immunodeficient mice (CB-17-Scid, H-2b) were reconstituted with isogeneic bone marrow stem cell antigen-1 (Sca-1)-positive cells and grafted with fetal thymus (BMSC-T), followed by transplant of allogeneic skin grafts from C57BL/6 (H-2d) mice. The control group include CB-17 non-Scid mice, CB-17-Scid mice, and CB-17 Scid mice pretransplanted with nonmodified isogeneic bone marrow cells and fetal thymus (BMC-T). RESULTS AND DISCUSSION: Skin allograft survival was significantly prolonged in the group pretransplanted with isogeneic BMSC-T compared the group of non-Scid mice and the group of Scid mice pretransplanted with BMC-T (59.6 days vs 7.1 days vs 11.7 days). In 2 of 10 mice pretransplanted with BMSC-T, the skin allografts transplanted immediately after BMSC-T survived for more than 100 days, but the third-party skin allografts transplanted at 100 days after BMSC-T transplant were rejected. The results suggest direct persistent contact of bone marrow Sca-1-positive cells with graft alloantigen may be a feasible approach to prolong allograft survival and induce tolerance in a small fraction of adult animals.     

The role of sialic acid in the dysfibrinogenemia associated with liver disease: distribution of sialic acid on the constituent chains

To further evaluate the role of sialic acid in the dysfibrinogenemia associated with liver disease, we studied the effect of removal of excess sialic acid residues from the fibrinogen of five patients with liver disease on the thrombin time and fibrin monomer aggregation. Patient fibrinogens containing 1.4-3.4 residues of sialic acid per molecule in excess of normal controls, with thrombin times 12-22 sec longer than normal and with abnormal fibrin monomer aggregation, were stripped of their excess sialic acid by incubation with Vibrio cholerae neuraminidase, followed by rapid removal of the enzyme by antineuraminidase antibody affinity chromatography. These partially desialylated patient fibrinogens, with a normal number of sialic acid residues remaining, exhibited normal thrombin times and normal fibrin monomer aggregation. Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of reduced normal, patient, and partially desialylated patient (sialyl-3H)-fibrinogen exhibited 60% of the radioactivity in the B beta chain and 40% in the gamma chain. There was no radioactivity detectable in the A alpha chain. These studies provide additional evidence that the increased sialic acid content of the acquired dysfibrinogenemia of liver disease is responsible for its functional defect and that the excess sialic acid is distributed on the B beta chain and gamma chains of the fibrinogen.     

Removal of silicone oil with vision improvement after rhegmatogenous retinal detachment following CMV retinitis in patients with AIDS

PURPOSE: To report that silicone oil may be safely removed from immuno-recovered patients with acquired immunodeficiency syndrome (AIDS) after instillation for cytomegalovirus (CMV)-related rhegmatogenous retinal detachment. METHOD: We report two patients with CMV-related retinal detachment who had previously been treated with vitrectomy and silicone oil. RESULTS: Six months after removal of silicone oil, the retina remained attached in both patients. Without specific anti-CMV therapy, there was no relapse of CMV retinitis while patients were undergoing highly active antiretroviral therapy. Best-corrected visual acuity improved in both patients. CONCLUSION: It appears to be possible to remove silicone oil safely from patients with AIDS who show immune recovery, thus avoiding side effects of long-standing silicone oil and increasing quality of life. After silicone oil removal, visual acuity was improved.     

The expression of somatostatin receptors 1 and 2 in benign,pre‐malignant and malignant laryngeal lesions

The expression of somatostatin receptors 1 and 2 in benign, pre‐malignant and malignant laryngeal lesions The role of chemotherapy in squamous cell carcinoma of the larynx has not been clearly defined. Whilst toxic chemotherapy regimes may confer a marginal improvement in survival, surgery and radiotherapy remain the mainstay of treatment. Somatostatin is a naturally occurring peptide, which exerts antiproliferative and antiangiogenic effects via five membrane‐bound receptor subtypes. The expression of somatostatin receptor subtypes (SSTRs) 1 and 2 was studied in benign, pre‐malignant and malignant laryngeal specimens. Epithelial expression of SSTR1 was detected in 4/6 (67%) Reinke's oedema, 5/6 (83%) pre‐malignant and 8/12 (67%) malignant specimens, with virtually no stromal or vascular expression. High levels of epithelial SSTR2 expression were noted in all Reinke's oedema specimens, compared with low‐to‐moderate levels in only 2/6 (33%) pre‐malignant and 3/12 (25%) malignant specimens (P < 0.01). This ‘loss’ of epithelial SSTR2 expression may provide a growth advantage in pre‐malignant and malignant laryngeal lesions. Vascular expression of SSTR2 was ubiquitous in all groups, with scant stromal expression. Overall, most (>80%) pre‐malignant and malignant laryngeal specimens expressed at least one of the two SSTR subtypes studied. Somatostatin analogues may have a therapeutic role in squamous cell carcinoma of the larynx.