ORCID Profile
0000-0003-1877-8227
Current Organisations
University of Leeds
,
Shandong University
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Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.JBIOMECH.2007.02.016
Abstract: Newer designs of total knee arthroplasty (TKA), through the use of added degrees of constraint, attempt to provide a "guided motion" to restore more normal and predictable kinematics. Two such design philosophies are the posterior stabilised (PS) using a cam-post and the medial pivot (MP) concepts. Knee kinematics of 12 patients with a PS TKA, 13 subjects with a MP TKA and 10 normal subjects were compared. For kinematic assessment, patients underwent fluoroscopic assessment of the knee during a step-up exercise and deep knee bend. Fluoroscopic images were corrected for distortion and assessed using 3D model fitting to determine relative 3D motion, and a 2D method to measure the patellar tendon angle (PTA) as function of knee flexion. For the PS design the cam-post mechanism engaged between 70 degrees and 100 degrees flexion. Between extension and 50 degrees there was forward motion of the contact points. Beyond 60 degrees both condyles rolled moved posteriorly. The majority of the external rotation of the femur occurred between 50 degrees and 80 degrees . The PTA was lower than normal in extension and higher than normal in flexion. The MP exhibited no anterior movement throughout the rage of motion. The medial condyle moved minimally. The lateral contact point moved posteriorly from extension to flexion. The femur rotated externally throughout the range of flexion analysed. The PTA was similar to normal from extension to mid flexion and then higher than normal beyond to high flexion. The PS design fails to fully restrain paradoxical anterior movement and although the cam engages, it does not contribute significantly to overall rollback. The MP knee does not show significant anterior movement, the medial pivot concept appears to achieve near normal kinematics from extension to 50 degrees of knee flexion. However, the results show that at high flexion this design does not achieve normal knee kinematics.
Publisher: Elsevier BV
Date: 07-2008
Publisher: Oxford University Press (OUP)
Date: 28-02-2019
DOI: 10.1002/BJS5.50138
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.MEDENGPHY.2008.05.007
Abstract: The recent development in Oxford lateral unicompartmental knee arthroplasty (UKA) design requires a valid method of assessing its kinematics. In particular, the use of single plane fluoroscopy to reconstruct the 3D kinematics of the implanted knee. The method has been used previously to investigate the kinematics of UKA, but mostly it has been used in conjunction with total knee arthroplasty (TKA). However, no accuracy assessment of the method when used for UKA has previously been reported. In this study we performed computer simulation tests to investigate the effect of the different geometry of the unicompartmental implant has on the accuracy of the method in comparison to the total knee implants. A phantom was built to perform in vitro tests to determine the accuracy of the method for UKA. The computer simulations suggested that the use of the method for UKA would prove less accurate than for TKA's. The rotational degrees of freedom for the femur showed greatest disparity between the UKA and TKA. The phantom tests showed that the in-plane translations were accurate to <0.5mm RMS and the out-of-plane translations were less accurate with 4.1mm RMS. The rotational accuracies were between 0.6 degrees and 2.3 degrees which are less accurate than those reported in the literature for TKA, however, the method is sufficient for studying overall knee kinematics.
Publisher: Springer Science and Business Media LLC
Date: 05-04-2018
DOI: 10.1007/S00464-018-6064-9
Abstract: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. This is a multicenter, international prospective cohort study. Consecutive s ling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33–4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76–2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42–0.71, p 0.001) and SSIs (OR 0.22, 95% CI 0.14–0.33, p 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11–0.44) and SSI (OR 0.21 95% CI 0.09–0.45). A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. Trial registration: NCT02179112.
Publisher: Oxford University Press (OUP)
Date: 2019
DOI: 10.1002/BJS.11051
Abstract: The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89·6 per cent) compared with that in countries with a middle (753 of 1242, 60·6 per cent odds ratio (OR) 0·17, 95 per cent c.i. 0·14 to 0·21, P & 0·001) or low (363 of 860, 42·2 per cent OR 0·08, 0·07 to 0·10, P & 0·001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference −9·4 (95 per cent c.i. −11·9 to −6·9) per cent P & 0·001), but the relationship was reversed in low-HDI countries (+12·1 (+7·0 to +17·3) per cent P & 0·001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0·60, 0·50 to 0·73 P & 0·001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 17-02-2022
Abstract: Biologic disease-modifying anti-rheumatic drugs (bDMARDs) are effective in treating inflammatory diseases and have been increasingly utilized over the past decade. Patients who receive bDMARDs have been shown to be at an increased risk for surgical site infection following surgical procedures. The severe consequences of infection following orthopaedic surgery have led to the practice of withholding bDMARDs perioperatively however, there has been no definitive evidence showing a clear benefit of withholding the use of bDMARDs, and in doing so, patients may be at an increased risk for higher disease activity. As such, the purpose of the present study was to compare the risk of infection, delayed wound healing, and disease flares associated with the use of bDMARDs in patients undergoing orthopaedic surgical procedures. We performed a systematic literature search of MEDLINE, Embase, and PubMed CENTRAL databases for studies comparing continuing and withholding the use of bDMARDs in patients undergoing orthopaedic procedures. Inclusion criteria were established following the PICO (Population, Intervention, Comparison, and Outcomes) approach: Population = patients who underwent orthopaedic surgical procedures and who were taking bDMARDs. Intervention = withholding the use of bDMARDs. Comparator = continuing the use of bDMARDs. Outcomes = surgical site infection, delayed wound healing, and disease flares. Article titles and abstracts were screened prior to review of the full text. Overall odds ratios (ORs) and associated 95% confidence intervals (CIs) for pooled effects were calculated. Eleven studies met the inclusion criteria, providing data for 7,344 patients, including 2,385 patients who continued and 4,959 who withheld their bDMARDs perioperatively. Continuing bDMARDs was associated with a significantly lower risk of disease flares (OR, 0.22 95% CI, 0.05 to 0.95 p = 0.04) and nonsignificant increases in surgical site infections (OR, 1.11 95% CI, 0.82 to 1.49 p = 0.49) and wound complications (OR, 2.16 95% CI, 0.48 to 9.85 p = 0.32). The present systematic review highlights the limited evidence supporting the current practice of stopping bDMARDs perioperatively. These findings suggest that patients may not be at an increased risk for developing infection or wound complications if bDMARDs are continued but are at an increased risk for disease flare if bDMARDs are withheld. However, our conclusions are limited by the retrospective and heterogenous nature of the data, and possibly by a lack of study power. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
Publisher: American Medical Association (AMA)
Date: 06-2022
Publisher: Elsevier BV
Date: 03-2008
DOI: 10.1016/J.KNEE.2007.11.008
Abstract: The in vivo kinematics of 10 patients after combined anterior cruciate ligament reconstruction (ACLR group) and Oxford unicompartmental knee arthroplasty (UKA) was compared to those of 10 Oxford UKA patients with an intact ACL (ACLI group) and a group of 22 normal knees. The kinematics during a step-up exercise and a deep knee bend exercise was measured using a fluoroscopic technique. The patellar tendon angle (PTA) to knee flexion angle relationship during both exercises was similar for all three groups of subjects. For the UKA groups the pattern of mobile bearing movement during both exercises was similar. This study demonstrates that normal knee kinematics is achieved in the ACL deficient arthritic knee following ACLR and UKA. As a result these patients, who tend to be young and high demand, have excellent outcome and achieve high levels of function. As the relative position of the components and thus component loading are similar to the ACLI UKA, we would expect similar long term survival.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: Saudi Arabia
No related grants have been discovered for Bernard van Duren.