Aim: The aim of this study was to investigate how psychological factors and illness perception can influence the recovery and functional outcome after total knee arthroplasty (TKA).

Patients and Methods: 100 patients who underwent primary total knee arthroplasty were included in this study. Pre-operatively patients were asked to complete a psychological questionnaire consisting of the revised Illness Perception Questionnaire (IPQ-r), Hospital Anxiety and Depression scale (HADS) and Recovery Locus of Control scale (RLOC). Function was assessed using Oxford Knee Score (OKS) and range of motion (ROM) pre-operatively and at six weeks and one year after surgery.

Results: Early results show that individual phychological variables correlate with the post-operative OKS at six weeks. Beliefs that the condition has a major effect on life and less understanding of the illness are associated with a poorer recovery. Women were found to have a higher degree of personal control, but this was not correlated with functional outcome. Patients with higher pre-operative OKS were more likely to suffer from anxiety and depression.

None of the investigated parameters predicted ROM at six weeks.

Discussion: Recovery from TKA surgery can be difficult to predict. This study showed that several psychological variables influence early functional outcome. These should be taken into account when considering patients for TKA surgery. Improving patient education, looking at home environment and social network as well as adressing anxiety and depression may help to improve overall outcome after TKA surgery.

The aim of this study was to determine whether there is a difference in the functional outcome between fixed and mobile bearings in total knee arthroplasty.

120 patients were randomized (computer generated) to receive either a fixed or mobile bearing P.F.C. Sigma total knee replacement. 96 patients were needed to detect a 20° difference in range of motion (ROM) with a significance level of 0.05 and a test power of 0.97. Oxford knee score (OKS) and ROM were assessed independently before and one year after surgery.

Mean ROM and Oxford knee score before and at one year after surgery for both groups are shown as preliminary results for 70 patients (follow-up expected to be completed by March 2006):

There is no statistically significant difference in the mean ROM at one year and in change in ROM between the two groups (p=0.53 and p=0.21 respectively). The findings were similar for Oxford Knee Score at one year and change in Oxford Knee Score (p=0.45 and p=0.82). There was no early aseptic loosening in either group.

The one year results suggest that there is no significant difference in functional outcome measured as ROM and Oxford Knee Score between the two types of bearing. Further follow-up will be carried out to detect any differences in the long term outcome.