To fully verify the reliability and reproducibility of an experimental method in generating standardized micromotion for the rat femur fracture model. A modularized experimental device has been developed that allows rat models to be used instead of large animal models, with the aim of reducing systematic errors and time and money constraints on grouping. The bench test was used to determine the difference between the measured and set values of the micromotion produced by this device under different simulated loading weights. The displacement of the fixator under different loading conditions was measured by compression tests, which was used to simulate the unexpected micromotion caused by the rat’s ambulation. In vivo preliminary experiments with a small sample size were used to test the feasibility and effectiveness of the whole experimental scheme and surgical scheme.Aims
Methods
To report early (two-year) postoperative findings from a randomized controlled trial (RCT) investigating disease-specific quality of life (QOL), clinical, patient-reported, and radiological outcomes in patients undergoing a total shoulder arthroplasty (TSA) with a second-generation uncemented trabecular metal (TM) glenoid versus a cemented polyethylene glenoid (POLY) component. Five fellowship-trained surgeons from three centres participated. Patients aged between 18 and 79 years with a primary diagnosis of glenohumeral osteoarthritis were screened for eligibility. Patients were randomized intraoperatively to either a TM or POLY glenoid component. Study intervals were: baseline, six weeks, six-, 12-, and 24 months postoperatively. The primary outcome was the Western Ontario Osteoarthritis Shoulder QOL score. Radiological images were reviewed for metal debris. Mixed effects repeated measures analysis of variance for within and between group comparisons were performed.Aims
Methods
The spiral blade modification of the Dynamic
Hip Screw (DHS) was designed for superior biomechanical fixation
in the osteoporotic femoral head. Our objective was to compare clinical
outcomes and in particular the incidence of loss of fixation. In a series of 197 consecutive patients over the age of 50 years
treated with DHS-blades (blades) and 242 patients treated with conventional
DHS (screw) for AO/OTA 31.A1 or A2 intertrochanteric fractures were
identified from a prospectively compiled database in a level 1 trauma
centre. Using propensity score matching, two groups comprising 177
matched patients were compiled and radiological and clinical outcomes
compared. In each group there were 66 males and 111 females. Mean
age was 83.6 (54 to 100) for the conventional DHS group and 83.8
(52 to 101) for the blade group. Loss of fixation occurred in two blades and 13 DHSs. None of
the blades had observable migration while nine DHSs had gross migration
within the femoral head before the fracture healed. There were two
versus four implant cut-outs respectively and one side plate pull-out
in the DHS group. There was no significant difference in mortality
and eventual walking ability between the groups. Multiple logistic
regression suggested that poor reduction (odds ratio (OR) 11.49,
95% confidence intervals (CI) 1.45 to 90.9, p = 0.021) and fixation
by DHS (OR 15.85, 95%CI 2.50 to 100.3, p = 0.003) were independent
predictors of loss of fixation. The spiral blade design may decrease the risk of implant migration
in the femoral head but does not reduce the incidence of cut-out
and reoperation. Reduction of the fracture is of paramount importance
since poor reduction was an independent predictor for loss of fixation
regardless of the implant being used. Cite this article:
