Comparison of patient outcomes in periarticular and intraarticular local anaesthetic infiltration techniques in total knee arthroplasty.

BACKGROUND: The use of local infiltration analgesia in the setting of knee arthroplasty is well established. There are no studies to date which have directly compared differences in infiltration techniques. The purpose of this study is to establish if a difference in patient outcomes exists when the infiltrate is injected into the periarticular tissues or directly into the joint. METHODS: One hundred and forty-two consecutive patients waitlisted for primary total knee arthroplasty were enrolled after primary exclusion criteria were applied. These included the following: allergy to study drugs, inability to receive spinal anaesthesia, and planned bilateral surgery. Patients were divided into two groups, a periarticular infiltration group (group A) and an intraarticular infiltration group (group B). Secondary exclusion criteria of regular opioid use, psychiatric illness, and serious medical comorbidity left a total of 47 patients in group A and 54 patients in group B. Both groups received a combination of 30 mg ketorolac, 500 µg of adrenaline, and 300 mg of ropivacaine, and normal saline. This was either injected into the periarticular tissues during surgery (group A) or intraarticularly after closure of the wound (group B). Primary outcome measures included opioid consumption during the first 24 h postoperatively and over the total admission, and visual analogue scales (VAS) on postoperative day 1 and at discharge. Secondary measures included Oxford Knee Score, knee flexion, length of stay, haemoglobin drop, and transfusion requirement. Ethics approval was granted by the hospital review board. The trial is registered in the Australian New Zealand Clinical Trials Registry, registration ACTRN12615000488505 . RESULTS: No statistically significant differences in postoperative analgesic use were observed between the two groups. However, there was a trend toward decreased postoperative patient-controlled analgesia use in the periarticular group (mean 53.1 vs 68.3 mg morphine equivalents; p = 0.093), as well as a statistically significant reduction in postoperative visual analogue pain scores. No statistically significant differences were observed for haemoglobin drop, range of motion, or pre- to 6-week postoperative Oxford Score difference. CONCLUSIONS: Our study is the first we are aware of to directly compare a periarticular to intraarticular injection technique when using local infiltration analgesia for total knee arthroplasty. Our results show no clear statistically significant benefit with either technique. The periarticular group showed a statistically significant reduction in postoperative VAS pain scores alongside a trend in that group toward reduced overall opioid use.

The ecological fallacy of the role of age in chronic disease and hospital demand.

OBJECTIVE: To examine the relationship between age and all-cause hospital utilization in the years preceding and following a diagnosis in hospital of heart failure, type 2 diabetes, or chronic obstructive pulmonary disease (COPD). RESEARCH DESIGN: A cohort study of all patients in Western Australia who have had a principal diagnosis of heart failure, type 2 diabetes, or COPD, upon admission to hospital. All-cause hospital utilization 6 years preceding and 4 years following cardinal events, that is, a disease-specific diagnosis upon hospital admission, where such an event has not occurred in the previous 2 years, are examined in specific age groups. RESULTS: Six years preceding a cardinal event, all-cause emergency department (ED) presentations are similar in all age groups, from under 55 to over 85 years of age, except in COPD where ED presentation rates are higher in younger groups. All-cause hospital inpatient days are transiently higher in the years preceding and following a cardinal event in older age groups, yet return to similar levels across all age cohorts after 4 years. ED presentations are significantly higher in the 4 years following cardinal events in younger compared with older groups. CONCLUSIONS: Longitudinal analysis of utilization around cardinal events overcomes the confounding effect of differences in chronic disease rates between age groups, avoiding a source of ecologic bias that erroneously attributes increasing utilization in individuals with chronic disease to age. Programs designed to reduce hospital demand in patients with chronic disease should possibly focus on younger, rather than older, individuals.

Reduced sensitivity of the renal vasculature to angiotensin II in young rats: the role of the angiotensin type 2 receptor.

BACKGROUND: The angiotensin type-2 receptor (AT2R) opposes the vasoconstrictor actions of angiotensin II (AngII) mediated through the angiotensin type-1 receptor (AT1R). Renal AT2R levels are high during fetal life, but decrease significantly during postnatal maturation. To provide insight into the functional role of the AT2R in the kidney during postnatal development, we investigated the effects of AT2R antagonism on cardiovascular responses to AngII in young and adult male rats. METHODS: In anesthetized 3- and 6-wk-old male Sprague-Dawley rats, mean arterial pressure (MAP) and renal blood flow (RBF) were measured in response to AngII in the presence of vehicle treatment or AT2R blockade with PD123319. RESULTS: The pressor effect of AngII and associated reduction in RBF were significantly less in 3-wk- than 6-wk-old rats. AT2R blockade potentiated the reduction in RBF in response to AngII in 3-wk-old rats only. CONCLUSION: In young rats, the AT2R modulates the response to AngII, blunting renal vasoconstriction. This effect is attenuated with age in association with a developmental reduction in renal AT2R expression. These findings may have implications for the development of novel therapies that target the renin-angiotensin system for the improvement of renal function in term and, in particular, preterm infants.

The ratchet effect: dramatic and sustained changes in health care utilization following admission to hospital with chronic disease.

OBJECTIVE: To describe the previously unexamined association between admissions to hospital with chronic disease and changes in all-cause health service utilization over time. RESEARCH DESIGN: A cohort study examining the population of Western Australia with hospitalizations for chronic disease from 2002 to 2010. A "rolling" clearance period is used to define "cardinal events," that is, a disease-specific diagnosis upon hospital admission, where such an event has not occurred in the previous 2 years. Changes in the rate of cardinal events associated with diagnoses of heart failure, type 2 diabetes, chronic obstructive pulmonary disease, cataract with diabetes, asthma, and dialysis are examined. Health service utilization (defined as inpatient days or emergency department presentations) 6 years preceding and 4 years following such events is presented. RESULTS: Cardinal events make up 40%-60% of all chronic disease admissions. A previously undescribed ratchet effect following cardinal events specifically associated with type 2 diabetes, heart failure, and chronic obstructive pulmonary disease is observed. This involves a 2- to 3-fold increase in inpatient days and emergency department presentations that are sustained for at least 4 years. CONCLUSIONS: Cardinal events represent an important reference point to understand the impact of chronic disease on health service utilization. Events that herald such a marked transition in health service demand have not been previously described.

High failure rates of the Spectron EF stem at a minimum of 10 year's follow-up.

We prospectively followed 112 hips, undergoing THA with a Spectron EF stem. At mean follow-up of 11.2years, 21 patients had died. We obtained radiological follow-up in 99% and clinical follow-up in 100% of the surviving 91 hips. Fifty-four percent demonstrated osteolysis in at least one Gruen zone. Twenty-two hips required revision for all causes, with a further five stems radiologically loose. With endpoint being stem revision for aseptic loosening or radiological failure, survivorship at 11years was 0.783. We believe the addition of a rougher surface finish has contributed to the high levels of osteolysis and stem failure seen with the Spectron EF.

Biostability, durability and calcification of cryopreserved human pericardium after rapid glutaraldehyde-stabilization versus multistep ADAPT(R) treatment in a subcutaneous rat model.

OBJECTIVES: Autologous pericardium rapidly fixed with glutaraldehyde (GA) in theatre is considered in many cardiac surgery centres the best material currently available for intracardiac, valvular or vascular repair. Implanted non-fixed autologous tissues suffer rapid degeneration, shrinkage and absorption whereas standard xenotypic fixed tissues cause local cytotoxicity and calcification. In the present study, using a subcutaneous rat model, we tested the biostability, durability and calcification potential of four different pericardium patches treated with GA and relevant to current clinical practice. METHODS: Pericardium samples were divided into four groups according to the method of treatment. Group I consisted of bovine pericardium (BP) fixed with 0.6% GA (control), Group II cryopreserved human pericardium (CHP) rapidly fixed with 0.6% GA for 4 min and detoxified with MgCl2, Group III CHP treated with the multistep ADAPT(®) process (delipidized, decellularized with Tx-100, deoxycholate, IgePal CA-630 and denucleased, fixed in 0.05% monomeric GA and detoxified) and Group IV BP treated with the multistep ADAPT(®) process (CardioCel(®)). Biostability was determined by shrinkage temperature which measures the degree of cross-linking, and durability assessed by resistance to a mixture of proteinases (pronase digestion). Treated pericardium samples (n = 10 in each of Groups I-IV) were implanted in the subcutaneous rat model for 8 and 16 weeks, followed by histology and calcium analysis (atomic absorption spectrophotometry). RESULTS: The biostability and the durability of both CHP and BP after the multistep ADAPT(®) treatment remained stable without any microscopic calcification. Extractable calcium levels of CHP were significantly (P < 0.01) reduced in Group II (1.89 ± 0.77 µg Ca/mg tissue) compared with Group I (64.37 ± 6.25 µg/mg) after 8 weeks. Calcification of CHP (Group III) and BP (Group IV) after the multistep ADAPT(®) treatment was significantly reduced (1.43 ± 0.48 µg/mg and 0.75 ± 0.10 µg/mg, respectively) compared with Group I (282.52 ± 18.26 µg/mg) and the rapidly treated CHP in Group II (11.32 ± 3.21 µg/mg) after 16 weeks. CONCLUSIONS: Improved biostability and durability with reduced calcification of tissues after the multistep ADAPT(®) tissue treatment suggest improved alternative substitutes to autologous pericardium.

Evaluation of a tissue-engineered bovine pericardial patch in paediatric patients with congenital cardiac anomalies: initial experience with the ADAPT-treated CardioCel(R) patch.

OBJECTIVES: This study evaluated the safety, efficacy and clinical performance of the tissue-engineered ADAPT® bovine pericardial patch (ABPP) in paediatric patients with a range of congenital cardiac anomalies. METHODS: In this single-centre, prospective, non-randomized clinical study, paediatric patients underwent surgery for insertion of the ABPP. Primary efficacy measures included early (<30 day) morbidity; incidence of device-related complications; haemodynamic performance derived from echocardiography assessment at 6- and 12-month follow-up and magnetic resonance imaging findings in 10 randomly selected patients at 12 months. Secondary measures included device-handling characteristics; shape and sizing characteristics and perioperative implant complications. The Aristotle complexity scoring system was used to score the complexity level of all surgical procedures. Patients completing the 12-month study were eligible to enter a long-term evaluation study. RESULTS: Between April 2008 and September 2009, the ABPP was used in 30 paediatric patients. In the 30-day postoperative period, no graft-related morbidity was observed. In total, there were 5 deaths (2 in the 30-day postoperative period and 3 within the first 6 postoperative months). All deaths were deemed due to comorbid non-graft-related events. Echocardiography assessment at 6 and 12 months revealed intact anatomical and haemodynamically stable repairs without any visible calcification of the patch. Magnetic resonance imaging assessment in 10 patients at 12 months revealed no signs of calcification. Fisher's exact test demonstrated that patients undergoing more complex, higher risk surgical repairs (Aristotle complexity score >8) were significantly more likely to die (P = 0.0055, 58% survival compared with 100% survival for less complex surgical repairs). In 19 patients, echocardiographic data were available at 18-36 months with no evidence of device calcification, infection, thromboembolic events or device failure. CONCLUSIONS: This study demonstrates the safety and efficacy of this engineered bovine pericardial patch as a cardiovascular substitute for surgical repair of both simple and more complex congenital cardiac defects.

Evaluation of smear layer removal by bicarbonate soda, ethylenediamine tetraacetic acid with cetrimide and sodium hypochlorite with a new model.

Various methods are used to evaluate irrigants. The primary aim was to develop a model for preliminary testing of potential irrigants. The second aim was to investigate the effect of bicarbonate soda on smear layer by comparing it with ethylenediamine tetraacetic acid with cetrimide (EDTAC) and sodium hypochlorite (NaOCl). Extracted human single-canal teeth were halved, and a uniform filing method was used to create smear layer. The following solutions were then applied - distilled water (control), 1% NaOCl, 17% EDTAC and bicarbonate soda at concentrations of 1%, 5%, 10% and 15%. Some samples had multiple solutions in different sequences. Samples were examined by scanning electron microscopy. Representative images were scored based on the degree of smear layer remaining. Results were analysed with the SAS system, using the GENMOD procedure. Complete smear layer was found in samples treated with all solutions except EDTAC used alone. There were no significant differences between the sequences, EDTAC/NaOCl/EDTAC and NaOCl/EDTAC/NaOCl. There were no significant differences between groups with and without bicarbonate soda. In conclusion, the model was effective for testing chemical effects on solutions on smear layer. Bicarbonate soda did not remove smear layer and provided no additional cleaning effects after EDTAC and NaOCl.