Recent National Institute for Health and Care Excellence (NICE) guidance has advised against the continued use of the Thompson implant when performing hip hemiarthroplasty and recommended surgeons consider using the anterolateral surgical approach over a posterior approach. Our objective was to review outcomes from a consecutive series of Thompson hip hemiarthroplasty procedures performed in our unit and to identify any factors predicting the risk of complications. 807 Thompson hip hemiarthroplasty cases performed between April 2008 and November 2013 were reviewed. 721 (89.3%) were cemented and 86 (10.7%) uncemented. 575 (71.3%) were performed in female patients. The anterolateral approach was performed in 753 (93.3%) and the posterior approach with enhanced soft tissue repair in 54 (6.7%). Overall, there were 23 dislocations (2.9%). Dislocation following the posterior approach occurred in 13.0% (7 of 54) in comparison to 2.1% (16 of 753) with the anterolateral approach (odds ratio (OR) 8.5 (95% CI 2.8 to 26.3) p < 0.001). Surgeon grade and patient history of cognitive impairment did not have a significant impact on dislocation rate. Patients were discharged home in 459 cases (56.9%), to a care home or other hospital in 273 cases (33.8%). 51.8% (338 of 653) returned home within 30 days. 75 died during their admission (9.3%). 30-day mortality was 7.1% and 1-year mortality was 16.6%.
Taper junctions between modular hip arthroplasty femoral heads and stems fail by wear or corrosion which can be caused by relative motion at their interface. Increasing the assembly force can reduce relative motion and corrosion but may also damage surrounding tissues. The purpose of this study was to determine the effects of increasing the impaction energy and the stiffness of the impactor tool on the stability of the taper junction and on the forces transmitted through the patient’s surrounding tissues. A commercially available impaction tool was modified to assemble components in the laboratory using impactor tips with varying stiffness at different applied energy levels. Springs were mounted below the modular components to represent the patient. The pull-off force of the head from the stem was measured to assess stability, and the displacement of the springs was measured to assess the force transmitted to the patient’s tissues.Objectives
Methods