Michael C. Parry

Rate in a population of patients who were managed with total knee arthroplasty with that in patients who were awaiting surgery. Methods: All patients undergoing primary total knee arthroplasty from 2000 to 2007 at a single institution were recorded. In the same period, all patients who were added to the waiting list for total knee arthroplasty were recorded. The mortality rate and time to death were calculated, and death certificates were retrieved for those who died within thirty or ninety days after the index event. Results: Two thousand, six hundred and ninety-five patients undergoing primary total knee arthroplasty were used for the thirty-day mortality calculation, and 2527 were used for the ninety-day mortality calculation. These patients were compared with 5857 and 5689 patients who were added to the waiting list for the thirty-day and ninety-day mortality calculations, respectively. There was no difference between the populations in terms of age or sex (p > 0.05). The thirty-day mortality following surgery was significantly greater for the surgery group (0.371%; 95% confidence interval, 0.202% to 0.682%) than for the waiting list group (0.0683%; 95% confidence interval, 0.0266% to 0.1755%) (odds ratio, 5.45; 95% confidence interval, 1.81 to 16.43). The ninety-day mortality was also significantly greater for the surgery group (0.792%; 95% confidence interval, 0.513% to 1.219%) than for the waiting list group (0.387%; 95% confidence interval, 0.256% to 0.585%) (odds ratio, 2.05; 95% confidence interval, 1.13 to 3.74). Conclusions: Primary total knee arthroplasty is associated with an increased risk of death at thirty and ninety days after the operation when compared with a population awaiting the same procedure. Increasing age was a risk factor for death following total knee arthroplasty. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence....

The classification and management of aseptic loosening of total hip arthroplasty remains a distinct challenge to the modern orthopaedic surgeon. The aim of this study was to assess the inter-observer and intra-observer reliability of commonly used classification systems for the assessment of bone stock loss in revision hip surgery. Radiographs of 23 femoral and 32 acetabular components in 30 patients were assessed using the Paprosky, AAOS and Endo-Klinik classification systems. A novel classification system was introduced and also used to assess the radiographs. Assessment was undertaken by 3 surgeons on 2 separate occasions and the inter- and intra- observer reliability calculated. The novel classification system showed a good to very good intra-observer reliability for both femoral and acetabular components (0.77–1.0; p<0.001), performing better than the other systems assessed. The novel femoral system demonstrated moderate to good inter-observer agreement (0.46–0.73), performing as well as the Paprosky (0.63–0.80) and AAOS (0.63–0.68) femoral systems. The novel acetabular system demonstrated fair to moderate inter-observer reliability (0.35–0.51) performing better than the AAOS acetabular classification (0.07–0.10) and as well as the Paprosky acetabular classification system (0.59–0.60). We propose this novel system as an alternative method for assessing bone stock loss in revision hip surgery.