Dislocation rate after hip arthroplasty within the first postoperative year: 36mm versus 28mm femoral heads
ABSTRACT Dislocation is a common and important complication of total hip arthroplasty (THA). Larger femoral heads may reduce the risk of dislocation and improve the range of movement. The aim of this study was to compare the relative risk (RR) of dislocation during the first year after THA between implants with 28 mm and 36 mm femoral heads. 198 consecutive hips with 28 mm femoral head (Group-28) and 259 hips with 36 mm femoral head (Group-36) were studied. The patients were assessed preoperatively and periodically using the Harris hip score (HHS) and radiographic analysis. The relative risk (RR) of dislocation was calculated. The average HHS significantly improved from a preoperative baseline to the last follow-up at 82.1 months (28 mm) and 44.3 months (36 mm). No statistically significant differences were revealed between the two groups for HHS results and complications (p>0.05), but the difference in RR of dislocation within the first year between the two groups was 7.85 (95% CI: 1.34-46.03), p=0.046.Although dislocation is multifactorial in etiology, the two groups were homogenous for all principal contributing factors except the diameter of the femoral head. Therefore, the use of 36-mm heads can reduce the risk of dislocation following THA by a factor of 8 compared to conventional 28 mm heads.
SourceAvailable from: Lars Nordsletten[Show abstract] [Hide abstract]
ABSTRACT: Background The surgical approach in total hip arthroplasty (THA) is often based on surgeon preference and local traditions. The anterior muscle-sparing approach has recently gained popularity in Europe. We tested the hypothesis that patient satisfaction, pain, function, and health-related quality of life (HRQoL) after THA is not related to the surgical approach. Patients 1,476 patients identified through the Norwegian Arthroplasty Register were sent questionnaires 1–3 years after undergoing THA in the period from January 2008 to June 2010. Patient-reported outcome measures (PROMs) included the hip disability osteoarthritis outcome score (HOOS), the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), health-related quality of life (EQ-5D-3L), visual analog scales (VAS) addressing pain and satisfaction, and questions about complications. 1,273 patients completed the questionnaires and were included in the analysis. Results Adjusted HOOS scores for pain, other symptoms, activities of daily living (ADL), sport/recreation, and quality of life were significantly worse (p < 0.001 to p = 0.03) for the lateral approach than for the anterior approach and the posterolateral approach (mean differences: 3.2–5.0). These results were related to more patient-reported limping with the lateral approach than with the anterior and posterolateral approaches (25% vs. 12% and 13%, respectively; p < 0.001). Interpretation Patients operated with the lateral approach reported worse outcomes 1–3 years after THA surgery. Self-reported limping occurred twice as often in patients who underwent THA with a lateral approach than in those who underwent THA with an anterior or posterolateral approach. There were no significant differences in patient-reported outcomes after THA between those who underwent THA with a posterolateral approach and those who underwent THA with an anterior approach.Acta Orthopaedica 06/2014; 85(5):1-7. DOI:10.3109/17453674.2014.934183 · 2.45 Impact Factor
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ABSTRACT: Hip joint dislocations related to total hip arthroplasty (THA) are a common complication especially in the early postoperative course. The surgical approach, the alignment of the prosthetic components, the range of motion and the muscle tone are known factors influencing the risk of dislocation. A further factor that is discussed until today is atmospheric pressure which is not taken into account in the present THA concepts. The aim of this study was to investigate the impact of atmospheric pressure on hip joint stability. Five joint models (Ø28–44 mm), consisting of THA components were hermetically sealed with a rubber capsule, filled with a defined amount of fluid and exposed to varying ambient pressure. Displacement and pressure sensors were used to record the extent of dislocation related to intraarticular and ambient pressure. In 200 experiments spontaneous dislocations of the different sized joint models were reliably observed once the ambient pressure was lower than 6.0 kPa. Increasing the ambient pressure above 6.0 kPa immediately and persistently reduced the joint models until the ambient pressure was lowered again. Displacement always exceeded half the diameter of the joint model and was independent of gravity effects. This experimental study gives strong evidence that the hip joint is permanently stabilized by atmospheric pressure, confirming the theories of the Weber brothers published in 1836. On basis of these findings the use of larger prosthetic heads, capsular repair and the deployment of an intracapsular Redon drain are proposed to substantially decrease the risk of dislocation after THA.Journal of Biomechanics 08/2014; 47(11):2660-2665. DOI:10.1016/j.jbiomech.2014.05.013 · 2.50 Impact Factor
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ABSTRACT: Aims: This study determined what activities are associated with total hip replacement (THR) dislocation to better inform patients about “at risk” activities. Methodology: All patients who attended our institution from December 2007 to May 2011 with a first-time dislocation following primary THR were retrospectively reviewed. This consisted of 100 patients, 31 males and 69 females, with a mean age at dislocation of 75 years. Major findings: Activities including getting into or out of bed, twisting or turning in bed, getting onto or up from a toilet and putting shoes, socks or stockings on were most frequently associated with THR dislocation. There was no difference in the activities associated with THR dislocation between the different age groups, surgical approach (anterolateral vs. posterior) or duration since primary THR. There was no difference in activities associated with dislocation between males and females except for putting socks/shoes/stockings on from a sitting position, where females reported a higher incidence of dislocation (14%) compared to males (0%). Principal conclusions: This study identified that patients should be specifically counselled to avoid picking objects up off the floor, to be vigilant when getting in or out of bed, and when getting off the toilet.Advances in Physiotherapy 05/2012; 14(2). DOI:10.3109/14038196.2012.685105