Our aim was to evaluate cementless one-stage revision in chronic periprosthetic hip joint infection. The study was performed as a multicentre, In total 56 PJI patients with a median age of 72 years and a median pre-operative ASA score of 2 met the established eligibility criteria and accepted to participate; 31 (55%) were males. The cohort had a mean follow-up time of 4.0 years, with all patients followed for minimum 2 years. The primary outcome were relapse described as re-revision due to infection (regardless of considered as a relapse or new infection). This was evaluated by competing risk analysis (competing risks: aseptic revisions and death). Secondary, all-cause mortality was evaluated by survival analysis. The study was approved by the local Committees on Biomedical Research Ethics.Aim
Method and patients
Studies of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA) have reported high complication and failure rates due to elevated metal ion levels. These rates were shown to be especially high for the Articular Surface Replacement (ASR) HRA, possibly due to its unique design. Associations between metal ion concentrations and various biological and mechanical factors have been reported. Component positioning as measured by acetabular inclination has been shown to be of especially strong consequence in metal ion production in ASR HRA patients, but few studies have evaluated acetabular anteversion as an independent variable. The primary objective of this study was to evaluate the associations between component orientation, quantified by acetabular inclination and anteversion, and blood metal ions. Secondly, we sought to report whether conventional safe zones apply to MoM HRA implants or if these implants require their own positioning standards. We conducted a multi-center, prospective study of 512 unilateral ASR HRA patients enrolled from September 2012 to June 2015. At time of enrollment our patients were a mean of 7 (3–11.5) years from surgery. The mean age at surgery was 56 years and 24% were female. All subjects had complete demographic and surgical information and blood metal ions. In addition, each patient had valid AP pelvis and shoot-though lateral radiographs read by 5 validated readers measuring acetabular abduction and anteversion, and femoral offset. A multivariate logistic regression was used with high cobalt or chromium (greater than or equal to 7ppb) as the dependent variable. The independent variables were: female gender, UCLA activity score, age at surgery, femoral head size, time from surgery, femoral offset, acetabular abduction, and acetabular anteversion.Introduction
Methods
48 patients (52 hips), with osteoarthritis, participated in a 5 year RSA study. Each patient received a VEPE liner, a porous titanium coated shell, and an uncemented stem with a 32mm head. Tantalum beads were inserted into the VEPE and the femur to measure head wear and stem stability using RSA. RSA and PROM follow-up was obtained postoperatively, 6 months, 1, 2, 3, and 5 years after surgery. The Wilcoxon signed-ranks test determined if changes in penetration or migration were significant (p≤0.05).Introduction
Methods
There is an apparent need for easily accessible research data on Periprosthetic hip joint infections (PJI)(1). Administrative discharge registers could be a valuable single-sources for this purpose, and studies originating from such registers have been published(2–4). However, the quality of routinely collected data for administrative purposes may be questionable for use in epidemiological research. The aim of this study was to estimate the positive predictive value of the International Classification of Disease 10th revision (ICD-10) periprosthetic hip joint infection diagnose code T84.5. The study was performed as a cross-sectional study on data extracted from the Danish National Patient Register. Patients with a registration of performed surgical treatment for hip PJI were identified via the ICD-10 code T84.5 (Infection and inflammatory reaction due to internal joint prosthesis) in association with hip-joint associated surgical procedure codes. Medical records of the identified patients (n=283) were verified for the existence of a periprosthetic hip joint infection. Positive predictive values with 95% confidence intervals (95% CI) were calculated. A T84.5 diagnosis code irrespective of the associated surgical procedure code had a positive predictive value of 85 % (95% CI: 80–89). Stratified to T84.5 in combination with an infection-specific surgical procedure code the positive predictive value increased to 86% (95% CI: 80–91), and in combination with a noninfection-specific surgical procedure code decreased to 82% (95% CI: 72–89). This study is the first to evaluate the only discharge diagnose code of prosthesis-related infection in an administrative discharge register. It is apparent, that codes in administrative discharge registers are prone to misclassification on an administrative level, either by wrongful coding by the physician or administrative personal in the registration process. Misclassification must be expected and taken into consideration when using single-source administrative discharge registers for epidemiological research on periprosthetic hip joint infection. We believe that the periprosthetic hip joint infection diagnose code can be of use in single-source register based studies, but preferably should be used in combination with alternate data sources to ensure higher validity(5) This study is funded in part by the Lundbeck foundation Centre for Fast-track Hip and Knee Surgery, Denmark.
