Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular cups during total hip arthroplasty (THA). This study aims to quantify the accuracy and precision of manual impaction strikes during the seating of an acetabular component. This understanding aims to help improve impaction surgical techniques and inform the development of future technologies. Posterior approach THAs were carried out on three cadavers by an expert orthopaedic surgeon. An instrumented mallet and introducer were used to insert cementless acetabular cups. The motion of the mallet, relative to the introducer, was analyzed for a total of 110 strikes split into low-, medium-, and high-effort strikes. Three parameters were extracted from these data: strike vector, strike offset, and mallet face alignment.Aims
Methods
Midfoot arthrodesis is the conventional surgical intervention for midfoot arthritis. Arthrodesis aims to stabilise, realign and fuse the affected joints, providing patients with improved pain and function. Current research neglects the measurement of patient reported outcomes. This study aimed to investigate objective, and patient reported outcomes of midfoot arthrodesis. The secondary aim was to identify variables predicting the development of non-union. An automated search of online patient records identified 108 eligible patients (117 feet). The rates of union, re-operations, and complications were calculated using radiographs and medical records. Logistic regression was used to model variables influencing the odds of non-union. All living patients were posted a Manchester Oxford Foot Questionnaire (MOx-FQ), a patient reported outcome assessment. Pre-operative MOx-FQ results were available in a minority of cases. Students t-test was used to compare pre- and post-operative MOx-FQ scores. The rate of union achieved was 74%. The rate of re-operations was 35%. The rate of complications was 14%. Bone grafts and staple fixation independently impacted the odds of non-union. Bone grafts decreased the odds of non-union, whilst staple fixation increased the odds. This finding agrees with the opinion of other researchers. We recommend the use of bone grafts, and the avoidance of fixation with staples. Previous attempts have been made to assess patient outcomes. However, this study is the first to use the MOx-FQ, a validated questionnaire. Therefore, this study establishes a baseline for improvements in patient reported outcomes.
