Range of motion and function are similar in patients undergoing TKA with posterior stabilised and high-flexion inserts

It is debatable whether high-flexion (HF) total knee arthroplasty (TKA) designs will improve postoperative flexion and function or will diminish the need for manipulation under anaesthesia (MUA). We retrospectively analysed range of motion (ROM), flexion, Knee Society Score (KSS), and rate of MUA in a consecutive group of patients who underwent TKA with a conventional posterior stabilised (PS) insert or an HF insert using identical surgical technique, implant design, and postoperative care. Fifty TKAs with a standard PS insert were matched for patient’s age, gender, preoperative ROM, and KSS with 50 TKA performed with an HF insert. The patient’s ROM and KSS were evaluated at six weeks, four months, and one year postoperatively. The outcome variables (flexion, ROM, KSS, and manipulation rate) in both groups were compared using the generalised estimating equations method. A second analysis of patients with preoperative flexion ≥120° was performed. The ROM, flexion, and patient-reported KSS was similar in both groups at each time period. The rate of MUA was also similar. Patients with a preoperative ROM of at least 120° showed similar results. Our study found that one year after surgery, patients who underwent TKA with a PS or an HF insert achieved similar flexion, ROM, and function.     

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015.     

Applications of porous tantalum in total hip arthroplasty

Porous tantalum is an alternative metal for total joint arthroplasty components that offers several unique properties. Its high volumetric porosity (70% to 80%), low modulus of elasticity (3 MPa), and high frictional characteristics make it conducive to biologic fixation. Tantalum has excellent biocompatibility and is safe to use in vivo. The low modulus of elasticity allows for more physiologic load transfer and relative preservation of bone stock. Because of its bioactive nature and ingrowth properties, tantalum is used in primary as well as revision total hip arthroplasty components, with good to excellent early clinical results. In revision arthroplasty, standard and custom augments may serve as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment, indicating potential for use in cases requiring reattachment of muscles and tendons to a prosthesis. Development of modular components and femoral stems also is being evaluated. The initial clinical data and basic science studies support further investigation of porous tantalum as an alternative to traditional implant materials.     

B-cell concentration in the apheretic product predicts acute graft-versus-host disease and treatment-related mortality of allogeneic peripheral blood stem cell transplantation

BACKGROUND: The influence of the graft composition on the clinical outcome after allogeneic peripheral blood stem cell (PBSC) transplantation is not well established. METHODS: The cellular composition of the apheretic products obtained from 63 human leukocyte antigen-identical siblings was prospectively correlated with the outcome of patients with hematological malignancies undergoing an allogeneic PBSC transplant after myeloablative conditioning. The concentration of nuclear, mononuclear, CD34+, T-cell subsets, B cells, and natural killer cells in the graft has been analyzed. RESULTS: In univariate analysis, acute graft-versus-host disease (GVHD) correlated with the disease (P=0.002), with the phase of disease at transplant (P=0.01), and with the number of CD20+ cells infused (P=0.05). In multivariate analysis, a dose of CD20+ cells in the graft higher than the median dose remained the only factor negatively affecting the incidence of acute GVHD (P=0.01; 95% confidence interval [CI]: 0.12-0.78). In univariate analysis, treatment-related mortality (TRM) correlated with the disease (P=0.04) and was negatively affected by a dose of infused B cells greater than the median value (28% versus 50%; P=0.02). In multivariate analysis, TRM was close to statistical correlation with the dose of CD20+ cells (P=0.06; 95% CI: 0.02-1.05). No other clinical parameter was influenced by the composition of the graft. CONCLUSIONS: Our results suggest that the concentration of B cells in the apheretic product may predict the incidence of acute GVHD and TRM in patients undergoing an allogeneic PBSC transplantation and open the way to the new preventive and therapeutic strategies for the management of GVHD.     

Activation of Coagulation and Fibrinolysis during Coronary Surgery: On-pump versus Off-pump Techniques

Background : The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques.

Methods : Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, [alpha]2 antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively.

Results : Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93-98%, P = 0.002, and 91.7% of baseline, 88-95%, P = 0.0001), respectively, whereas [alpha]2-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66-85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91-99%, P = 0.011), and increased D-dimer formation (476%, 309-741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups.     

Demographics, outcomes, and risk factors for adverse events associated with primary and revision total hip arthroplasties in the United States

We conducted a study to analyze nationally representative data on patient and health care system characteristics and in-hospital outcomes associated with primary and revision total hip arthroplasties in the United States. Between 1990 and 2004, there were an estimated 2,748,187 hospital discharges after total hip arthroplasty. The risk factors we identified for procedure-related complications and in-hospital mortality included revision procedures, increased age, and male sex. Compared with smaller hospital capacity (number of beds), large hospital capacity was associated with a decreased odds ratio for complications but an increased risk for in-hospital mortality. Additional studies are warranted to determine causal relationships.     

Incorporation of vancomycin-supplemented bone allograftsRadiographical,histopathological and immunohistochemical study in pigs

We compared the incorporation of bone allografts with or without vancomycin in tibial defects of 18 pigs. High-quality radiographs, histological examination, immunological expression of metalloproteinase-13 (MMP-13) and transforming growth factor-beta 2 (TGFß2) indicated that there was no significant difference in bone allograft incorporation between up to 220 times the MIC (minimum inhibitory concentration) in bone allografts with 1 g of vancomycin in each 300 g of allograft or without this supplement.     

Prevalence,Risk Factors,and Management of Proximal Femoral Remodeling in Revision Hip Arthroplasty

The prevalence of, risk factors, and management of proximal femoral remodeling in revision total hip arthroplasty is unknown. Therefore, we reviewed the files of 200 consecutive femoral revision arthroplasties to study this phenomenon. Remodeling was considered present if a properly sized diaphyseal-engaging acrylic template had appropriate distal canal fill but lied within 2 mm of the proximal lateral endosteal cortex (definition 1) or completely outside the femoral canal (definition 2) on anteroposterior femoral radiographs. The prevalence of remodeling was 42% by definition 1 and 21% by definition 2. The strongest risk factors were loose femoral components and more severe femoral bone loss. Orthopedic surgeons performing revision arthroplasty should be prepared to encounter remodeling as its presence can complicate femoral component revision.     

Esmolol for potentiation of nitroprusside-induced hypotension: impact on the cardiovascular, adrenergic, and renin-angiotensin systems in man

Esmolol infusion at rates of 200, 300, and 400 micrograms.kg-1.min-1 was used to potentiate hypotension (mean arterial pressure = 60 mm Hg) induced with sodium nitroprusside (SNP) in 10 male patients undergoing radical cancer surgery during nitrous oxide-oxygen and fentanyl anesthesia. Heart rate (HR), blood pressure (radial arterial catheter), and plasma levels of renin activity (PRA), norepinephrine (N), epinephrine (E), and dopamine (D) were measured: 1) while patients were awake; 2) after induction of anesthesia (nitrous oxide, 60% in oxygen, fentanyl = 5 micrograms/kg followed by an infusion at 10 micrograms.kg-1.hr-1); 3) after surgery had begun; 4) after 20 minutes of SNP-induced hypotension; 5) after 20 minutes of esmolol at each of the above infusion rates; and 6) after the completion of surgery. Compared to awake values, SNP-induced hypotension (mean infusion rate = 3.1 micrograms.kg-1.min-1 +/- 0.6 SE) during surgery resulted in significant (P less than 0.05) increases in heart rate, PRA, N, and D. Infusion of esmolol resulted in significant (P less than 0.05) dose-dependent reductions in SNP requirement to maintain MAP = 60 mm Hg. At 200 micrograms.kg-1.min-1, SNP requirement was 2.1 micrograms.kg-1.min-1 +/- 0.4, at 300 micrograms.kg-1.min-1, it was 1.0 micrograms.kg-1.min-1 +/- 0.2, and at 400 micrograms.kg-1.min-1, was 0.5 micrograms.kg-1.min-1 +/- 0.3. Concomitant with the decrease in SNP requirement, there were significant reductions in HR and PRA at all infusion rates of esmolol.(ABSTRACT TRUNCATED AT 250 WORDS)