Introduction

Dislocation as a primary cause of revision has been on the increase in Sweden (14% in 2014). The increasing use of Dual Mobility cups (DMC) could well be explained by the increased revision burden due to dislocation, patients undergoing revision having increased comorbidities and reports that dual articular cup designs reduce the risk of dislocation. The aim of this study was to analyze the change in utilization pattern of the dual articular designs used in acetabular revision surgery in Sweden. The short-term survival of DMC was compared to traditional designs.

In medical research and among health-care providers there has been a marked shift to a focus on patient-reported outcome (PRO) and how it is measured and analysed. In this study from the Swedish Hip Arthroplasty Register we present the development and results of a nationwide, prospective, observational follow-up programme including patient-reported outcome measures (PROMs). The programme started in 2002 and has gradually expanded to include all units performing THA surgery in Sweden. The self-administered PROM protocol comprises the EQ-5D instrument, the Charnley categorization and visual analogue scales (VAS) for pain and satisfaction. These current analyses include 34 960 THAs with complete pre- and one-year postoperative questionnaires.

Patients eligible for THA generally report low health-related quality of life (HRQoL) and suffer from pain. One year post-operatively the mean EQ-5D index increased from 0.41 to 0.78 (p<0.001) which is above the level of an age- and gender-matched population. Pain was reduced from mean VAS 62 to 14 (p<0.001). Females, younger patients and those with Charnley category C reported lower EQ-5D index pre-operatively than males, older patients and Charnley A or B, respectively, did (all p<0.001). In a multivariable regression analysis Charnley category C, male gender and higher age were associated with less improvement in HRQoL (p<0,001). Patients' response rates to the Registry was 86% pre-operatively and 90% one year post-operatively.

Nationwide implementation of a PROM programme requires a structured organization and effective IT solutions. The continuous collection of PROs permits local and national improvement work and allows for further health-economic evaluation.

This randomised methodological study sought to test the reliability of an Internet questionnaire and investigate the differences in response rates between traditional pen-and-paper questionnaires and Internet questionnaires for measuring patient-reported outcome after total hip arthroplasty (THA) surgery.

From the Swedish Hip Arthroplasty Register, 2 400 patients were chosen at random but stratified by age, sex and diagnosis for inclusion in a four-year follow-up using the health-related quality of life (HRQoL) tool EQ-5D and visual analogue scales for pain and satisfaction. The patients were randomized to answer the follow-up model protocol either via a password-protected Internet questionnaire or via a mailed pen-and-paper questionnaire.

A reliability test for the Internet follow-up instrument showed adequate correlation. However, the Internet group and the pen-and-paper group differed significantly (p<0.001) with a 92% response rate in the latter and 49% in the former. Adjusted to the normal age distribution of the THA population, the Internet response rate was 34%.

The patient-administered Internet questionnaire alone does not give a sufficient response rate in the THA population to replace the pen-and-paper questionnaire. However, the system is reliable and could be used for measuring patient- reported outcome if supplemented with traditional pen-and-paper questionnaires for Internet non-respondents. It is expected that this answer procedure will soon predominate in view of the general development of Internet functions. Register work may then become less resource-consuming and the results may be analysed in real time.

Introduction: In the Swedish health care system waiting time for THR surgery has been unacceptable long. There are several hip disease related circumstances that generates costs for the society and the patient. In order to perform complete health economic analysis these costs have to be assessed.

Patients and Material: Prior to THR surgery, 3500 patients from 20 hospitals were asked to complete a questionnaire regarding cost generating events related to the hip disease. Individual data on waiting time were collected. Follow-up questionnaire was administered one year postoperatively.

Preliminary results: 2712 patients answered the pre-operative questionnaire. The sample was representative; mean age 69 years, 67% > 65 years (retirement age). Mean waiting time for orthopaedic consultation was 176 days and for surgery 312 days. 82% used any medication due to the hip disease. Among the non-retired patients 33% were on sick leave and 25% were on disability pension. 4% reported home-help service, 9% transportation service for disabled, and 46% had any home modification. 26% required help from relatives in various extents. The costs related to hip disease amounts to 8 000 Euro one year prior to surgery. Productivity loss constitutes 72% of total costs, health care costs 13%, municipal costs 6%, medication 1,5% and costs for relative care-taking 7,5%.

Discussion: Productivity loss constitutes the principal cost for hip disease in patients eligible for THR surgery. One year on the waiting list costs equals the surgery cost. The waiting time for orthopaedic consultation and subsequent surgery is unacceptable long. Baseline cost data is important for further adequate health economic analyses.

Objective: The Charnley grading system (A, B, C) has previously been shown to be a valid predictor concerning outcome after joint replacement surgery. In this study we hypothesized that anxiety/depression, one of five dimensions in the health related quality of life measurement tool EQ-5D, could predict the outcome after total hip replacement surgery.

Methods: Data from the Swedish Hip Arthroplasty Register including 6 158 patients with primary osteoarthritis were analysed. To examine the association of anxiety with respect to the outcome of pain (VAS) and satisfaction (VAS) a general linear regression model was used.

A subgroup of 481 patients in the Western Region of Sweden with complete data on individual CPP (cost per patient) was selected for the health economic analysis.

Results: The preoperative EQ-5D anxiety/depression dimension was a strong predictor for pain relief, patient satisfaction, and cost-effectiveness with surgery. Patients with comorbidity (Charnley category C) had a significant worse outcome with regards to pain relief, satisfaction and EQ-5D index scores than patients in Charnley category A and B (p< 0.001). Females generally had worse outcome scores than males in all three outcome measurements (p< 0.001).

Conclusion: Orthopaedic surgeons involved with the care of patients eligible for THR surgery should be alert to the fact that mental health may influence pain-experience and HRQoL outcome. Appropriate assessment of mental health may enable us to modify the approach in which we manage these patients, in order to optimize the outcome following joint replacement surgery.

Introduction: Many patients eligible for hip arthroplasty suffer from bilateral hip disease with indication for bilateral total hip replacement (BTHR). Traditionally two-stage BTHR is far more common than one-stage procedure due to the risk of complications. However, most studies are in favour of one-stage BTHR in the healthy and young people. This study was designed to further analyse mortality, outcome, complications and cost-effectiveness after one-stage BTHR surgery.

Patients and Methods: In this prospective matched control study we examined 32 patients with BTHR hybrid surgery. The control group of 32 patients with unilateral hybrid THR was derived from Sahlgrenska University hospital. The follow up time was 1 year. Medical records, cost per patient database, records from Swedish Social Insurance Administration and HRQoL outcome measurements from the Swedish Hip Arthroplasty Register were used for the analyses.

Mortality data from the Register regarding all 950 patients with one-stage BTHR surgery during the period 1992 until 2005 were compared to those 2577 who had had a twostage procedure with less than six months between the operations.

Preliminary Results: There were no major differences in complications. The intraoperative bleeding was higher in the BTHR patients and they required more blood transfusion. Length of hospital stay was in average 10,2 days for the one-stage BTHR group and 7,6 days for the unilateral group. Preoperative EQ-5D index was 0,14 in the BTHR group and 0,31 in the control group. Mean EQ-5D gain after 1 year was 0,77 and 0,40 respectively. Hospital costs were only 60% higher in the one-stage BTHR group. Among the employed patients there were no differences in days of sick pay and cost of sick pay in the two groups. Among the 950 subjects with one-stage BTHR surgery, the 90 day mortality was 0,32% compared to 0,42% in the group of 2577 patients with two-stage procedure.

Discussion: In healthy patients with bilateral hip disease requiring bilateral arthroplasty one-stage BTHR is highly cost-effective and safe. There is even lower 90 day mortality for the onestage operated subjects in the register but this is probably due to a natural selection of younger and healthier patients. The one-stage procedure reduces the total time of rehabilitation which is of particular importance for people in working age. Cautiously estimated, performing another 100 one-stage BTHR per year instead of two-stage procedure would save 16–20 million SEK yearly in Sweden.