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BACKGROUND: After more than 4 decades experience of total knee arthroplasty (TKA), there is still a group of patients who are not satisfied with the outcome. In spite of the improvement of many aspects around the procedure, for unexplainable reasons, patient dissatisfaction is still approximately the same. We conducted this study to analyze correlations between preoperative psychological aspects and dissatisfaction after TKA.METHODS: A total of 186 patients were operated with a primary TKA. Patients filled out the Hospital Anxiety and Depression Scale, Visual Analog Pain Scale (0-100), and Knee injury and Osteoarthritis Outcome Score preoperatively and 4 years postoperatively. Four years postoperatively, the patients also scored their satisfaction degree with the outcome of the surgery.RESULTS: Of 186 patients, 27 (15%) reported that they were dissatisfied or uncertain with the result of their TKA 4 years postoperatively. Sixteen of those 27 patients had reported anxiety/depression preoperatively compared with 11 of 159 (7%) in the satisfied or very satisfied groups. Patients with preoperative anxiety or depression had more than 6 times higher risk to be dissatisfied compared with patients with no anxiety or depression (P < .001). Patients with deep prosthetic infection had 3 times higher risk to be dissatisfied with the operation outcome (P = .03). Dissatisfied patients had 1-day longer hospital stay compared with the satisfied group (P < .001).CONCLUSION: Preoperative anxiety and/or depression is an import predictor for dissatisfaction after TKA. Psychological assessment and treatment preoperatively might improve degree of satisfaction.

Article, Areal bone mineral density (aBMD), as measured by dual-energy X-ray absorptiometry (DXA), predicts hip fracture risk only moderately. Simulation of bone mechanics based on DXA imaging of the proximal femur, may help to improve the prediction accuracy. Therefore, we collected three (1−3) image sets, including CT images and DXA images of 34 proximal cadaver femurs (set 1, including 30 males, 4 females), 35 clinical patient CT images of the hip (set 2, including 27 males, 8 females) and both CT and DXA images of clinical patients (set 3, including 12 female patients). All CT images were segmented manually and landmarks were placed on both femurs and pelvises. Two separate statistical appearance models (SAMs) were built using the CT images of the femurs and pelvises in sets 1 and 2, respectively. The 3D shape of the femur was reconstructed from the DXA image by matching the SAMs with the DXA images. The orientation and modes of variation of the SAMs were adjusted to minimize the sum of the absolute differences between the projection of the SAMs and a DXA image. The mesh quality and the location of the SAMs with respect to the manually placed control points on the DXA image were used as additional constraints. Then, finite element (FE) models were built from the reconstructed shapes. Mean point-to-surface distance between the reconstructed shape and CT image was 1.0 mm for cadaver femurs in set 1 (leave-one-out test) and 1.4 mm for clinical subjects in set 3. The reconstructed volumetric BMD showed a mean absolute difference of 140 and 185 mg/cm3 for set 1 and set 3 respectively. The generation of the SAM and the limitation of using only one 2D image were found to be the most significant sources of errors in the shape reconstruction. The noise in the DXA images had only small effect on the accuracy of the shape reconstruction. DXA-based FE simulation was able to explain 85% of the CT-predicted strength of the femur in stance loading. The present method can be used to accurately reconstruct the 3D shape and internal density of the femur from 2D DXA images. This may help to derive new information from clinical DXA images by producing patient-specific FE models for mechanical simulation of femoral bone mechanics., final draft, http://purl.org/eprint/status/PeerReviewed