The CCI mobile bearing ankle implant used at our orthopedic department 2010–2013, was abandoned due to failures and findings of bone loss at revision. The aim of this study was to a) Determine our true revision rate, b) Investigate accuracy of measuring prevalence, size and location of periprosthetic bone cysts through X-ray and CT and c) Relate these findings to implant alignment and patient reported outcome measurements (PROMs). 51 primary surgeries were performed, prior to this study 8 had been revised. Out of 43 un-revised patients, 36 were enrolled and underwent evaluation with metal artefact reduction CT-scans and conventional X-ray. They filled out 3 PROMs; SEFAS, SF-12, EQ-5D. Cyst volume larger than 0.1 ml was measured using VITREA volume tools for CT-scans and calculation of spherical volume for X-rays; using AP- and lateral projections. Location of lesions was recorded, according to their position relative to the implant. Medial-/lateral- and anterior-/posterior tilt of the implant parts was measured using IMPAX built in measuring tools, applied to AP- and lateral X-ray projection. The relation between lesions location and alignment of components was analyzed by logistic regression. Bias and ICC estimation between CT and X-ray was analyzed by mixed effect model. Log transformation was used to fit the normal distribution assumption. PROMs association to osteolytic volume was analyzed by linear- and logistic regression. P-values of 0.05 were considered statistically significant. Finding large osteolytic lesions caused 4 additional patients to undergo revision and 7 are being monitored due to high risk of failure. Of the original 51 implants 14 have been revised. 8 cases because of osteolytic lesions and aseptic loosening (true revisions w. exchange of components or bone transplants), 3 periprosthetic fractures (2 non-traumatic fractures) and 3 cases of exostosis. The 3- and 5 year revision rate was 14% and 16% for true revisions and 17% and 27% overall. Cystic lesions were found in 81% of participants. Total cyst-volume was on average 13% larger on X-ray, however this difference was not significant (p = 0.55), with intraclass correlation being 0.66. Total cystic volume was not significantly related to PROM-scores (P 0.16–0.5). Location of cysts showed association with alignment of components (P 0.02–0.08). Mean tibia component anterior tilt was 89 degrees (SD 4). Mean medial tilt was 91 degrees (SD 3) for the tibial and 90 degrees (SD 4) for the talar component. The implant investigated performs below standard, compared to public registries1, 2that report overall 5 year revision rates at 5 – 6.5%. We obtained larger measurements from X-rays than CT, unlike previous studies comparing these modalities. Cysts were common and large. Correlation between lesion location and alignment of implant, with valgus and anterior tilt of components causing more lesions in adjacent zones, may suggest a link between implant failure and alignment of components.
Randomized, controlled trials (RCTs) are generally accepted as the “gold standard” for the provision of the most unbiased measures of the efficacy of interventions but are often criticized for the lack of external validity. We assessed the external validity of a RCT examining the efficacy of local infiltration analgesia (LIA) compared with continuous epidural infusion after total knee arthroplasty (TKA) During a one-year period, all patients consecutively admitted for elective, unilateral, primary TKA were identified as potential participants. All underwent eligibility screening to determine who were eligible for participation in a randomized controlled trial. We investigated the distribution of preoperative characteristics and postoperative variables among excluded patients, non-consenters, and enrolled and randomized participants.Background
Methods
The purpose of the present study was to identify risk factors for lag-screw cut-out following osteosynthesis of intertrochanteric fractures. The study was a case-control study using a sex and age matched control group. The fractures were classified according to Evans and OTA/AO classifications. Operative treatment was performed using dynamic hip-screw or cephalomedullary nailing systems. All patients were followed for at least 3–4 months postoperatively. The following risk factors were assessed: fracture type, quality of reduction by blinded assessment using a visual analogue scale, tip-apex distance (TAD) according to Baumgaertner, lag-screw positioning and other relevant additional risk factors in terms of walking ability, osteoporosis, cardio-vascular disease, neurological disease, diabetes, obesity, alcohol consumption and smoking.Introduction
Materials and methods
To compare regional body composition, bone mineral density (BMD), and clinical outcome in patients with two different shoulder arthroplasty designs. This cross-sectional study included 54 patients with a total of 63 shoulder arthroplasties. There were 18 men and 45 women with a mean age of 68.9 years SD ± 10.5. Mean follow-up time was 39.2 months SD ± 14.4. The patients were divided into three groups according to their history: 22 patients were diagnosed with a proximal humeral fracture and treated with a stemmed hemi arthroplasty, 11 patients were diagnosed with osteoarthritis and treated with a stemmed hemi arthroplasty, and 30 patients were diagnosed with osteoarthritis and treated with a resurfacing arthroplasty. All patients underwent a one-day protocol: Regional Dual X-ray Absorptiometri (DXA) was used to measure BMD of the distal third of humerus and regional body composition of the upper arm. The clinical outcome was measured using Western Ontario Osteoarthritis of the Shoulder index (WOOS) and Constant-Murley score.Objective
Materials and Methods
