Background

Prosthetic implants used in primary total hip replacements have a range of bearing surface combinations (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, metal-on-metal); head sizes (small <36mm, large 36mm+); and fixation techniques (cemented, uncemented, hybrid, reverse hybrid), which influence prosthesis survival, patient quality of life, and healthcare costs. This study compared the lifetime cost-effectiveness of implants to determine the optimal choice for patients of different age and gender profiles.

The risk of dying following total hip replacement (THR) is low and has declined over the last decades. The influence of comorbidities and worse physical status on mortality leads to the idea that patient-reported health status may also be a predictor of mortality. Although this has not been demonstrated in THR surgery, some studies in other fields have reported an association. The aim of this study was to investigate the relationship between patient-reported health status before THR and the risk of dying up to 5 years post-operatively.

The Swedish Hip Arthroplasty Register runs a nationwide PROMs program including the EQ-5D questionnaire to routinely monitor patients undergoing THR in Sweden. For these analyses, we used register data on 42,862 patients with hip osteoarthritis operated with THR between 2008 and 2012. Relative survival ratio was calculated by dividing the observed survival in the patient group by age- and gender-adjusted expected survival of the general population. Multivariable modelling proceeded with time-transformed Cox proportional hazards. Pre-operative responses to the five EQ-5D dimensions along with age, gender, education status, year of surgery, and hospital type were used as independent variables.

As a group THR patients had a better survival than the general population. Broken down by the five EQ-5D dimensions we observed differentiated survival patters. For all dimensions, those reporting moderate problems (level 2) had higher mortality than those reporting no problems (level 1) and those reporting extreme problems (level 3) had higher mortality than those reporting level 1 or 2.

Worse health status according to the EQ-5D before THR is associated with higher mortality up to five years after surgery. The complexity of the interactions between different patient-factors associated with outcomes complicates accurate assessments of risks and expected benefits for individual patients. EQ-5D responses may be useful in a multifactorial individualized risk assessment before THR.

Prospectively collected data is an important source of information subjected to change over time. What surgeons were doing in 1999 might not be the case anymore in 2016 and this change in time also applies to a number of factors related to the performance and outcome of total hip replacement. We evaluated the evolution of factors related to the patient, the surgical procedure, socio-economy and various outcome parameters after merging the databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare.

Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged with databases including general information about the Swedish population and about hospital care. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length of stay, mortality rate, adverse events, re-operation and revision rates and PROMs.

Most patients were operated because of primary osteoarthritis and this share increased further during the period at the expense of decreasing number of patients with inflammatory OA and hip fracture. Comorbidity and ASA scores increased for each year. The share of all cemented implants has dropped from 92% to 68% with a corresponding increase of all uncemented from 2% to 16%.

Length of stay decreased with about 50 percent to 4.5 days in 2012. The 30- and 90-day mortality rate dropped to 0.4% and 0.7%. Re-operation and revision rates at 2 years were lower in the more recent years. The postoperative PROMs are improving despite the preoperative pain scores getting worse.

Even in Sweden, always been considered as a very conservative country with regards to hip replacement surgery, the demographics of the patients, the comorbidities and the primary diagnosis for surgery are changing. Despite these changes the outcomes like mortality, re-operations, revisions and PROMs are improving.

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.

Background

In Sweden approximately 6000 patients yearly sustain displaced femoral neck fractures. During the last decade there has been a shift towards more arthroplasties at the expense of internal fixation. In 2008 approximately 75% of the dislocated femoral neck fractures in Sweden were treated with arthroplasties. Those patients are typically elderly and frail and the vast majority of them receive hemiarthroplasties. In 2005 a national hemiarthroplasty registration was established as part of the Swedish Hip Arthroplasty Register (SHAR).

Introduction: Revision rate after THA in the younger age groups is still unacceptable high and might up to 20% after 10 years. The aim of this investigation is to evaluate risk factors for later revision in patients younger than 50 years at surgery based on the NARA database (Nordic Arthroplasty Register Association).

Materials and Methods: 14,610 primary THA from Denmark, Sweden, and Norway, operated from 1995 to 2007, were included. 49.4% was males, the diagnosis was idiopathic osteoarthrosis (OA) in 46%, childhood disease in 26%, inflammatory arthritis (IA) in 12%, non-traumatic osteonecrosis in 9% and fracture in 6%. 49% of the THA’s were uncemented, 27% cemented, 14% hybrid, and 8% were inverse hybrid THA’s. Cox multiple regression, adjusted for diagnose, age, gender, calendar year and surgical approach, was used to calculate prosthesis survival with any revision as end-point. RR= relative risk (CI= confidence interval).

Results: The overall 10-year survival was 83%. There was no difference between gender (RR=0.94 (0.82–1.07)). IA had a 37% reduced risk of revision compared with OA (RR=0.67 (0.54–0.84)), whereas there was no difference between childhood disease and primary osteoarthrosis. Overall, cemented, uncemented and reverse hybrid THA had a better survival than hybrid THA. Hybrid THA had 24% increased risk compared with cemented (RR=1.24 (1.04–1.49)). There were no difference between cementless and cemented (RR=1.07 (0.92–1.26)). Interestingly, the inverse THA had lower revision rate than cemented THA in men (RR=0.50 (0.25–0.99)). The risk for revision due to aseptic loosening was lowest in cementless THA and reduced to RR=0.55 (0.44–0.69) compared with cemented THA.

Discussion: and Conclusion: Choice of prosthetic concept for younger patients is still of debate. The present study including only patients younger than 50 years of age, showed that overall cemented, uncemented and reverse hybrid THA, had better survival than traditional hybrid. The risk for revision due to aseptic loosening was higher in cemented than cementless THA.

Introduction: There is an increasing interest in surface replacement arthroplasty (SRA) as an alternative to conventional THA (cTHA) in young and active patients. However, there has been considerable variability in reported outcomes. National joint registry reports have shown increased revision rates compared to cTHA. We analysed outcome measured as non-septic revision rate within two years for SRA in the NARA data base (Nordic Arthroplasty Register Association).

Materials and Methods: 1638 SRA and 163802 cTHA with age up to 73 years and a non-fracture diagnosis, operated from 1995 to 2007, were compared using Cox multiple regression including age, gender, diagnosis, nation and prosthesis type with cTHA divided into cemented, uncemented, hybrid and reversed hybrid fixation. Men below 50 years of age (460 SRA and 7185 cTHA) were analysed as a subset. The SRA cohort with a mean follow-up 1,8 years was also analysed with the same method including age, gender, diagnosis, number of performed SRA per hospital and the four most commonly used prosthesis designs. In an additional analysis femoral head diameter was added, reducing the number of cases to 1552. results are presented as relative risk (RR) with 95 % confidence interval(CI).

Results: SRA had a more than twofold increased revision risk compared to cTHA, RR=2,50 (1,67–3,70), which increased to 3,63 (2,42–5,44) when compared with all cemented THA. In the subpopulation of men below 50 years of age, there was no difference between SRA and any of the cTHA cathegories. Within the SRA group RR was reduced by male gender, RR=0,46 (0,25–0,86), in hospital performing > 70 SRA (RR=0,26, 0,11–0,60) and with use of BHR (Birmingham Hip Resurfacing) compared to all other designs (RR=0,27, 0,12–0,61). The size of the femoral head diameter had no significant influence on the early revision rate.

Discussion and Conclusion: Surface replacement arthroplasty has an increased risk of early revision compared to conventional and cemented THA except for men below 50 years of age. There is a learning curve on the hospital level. Cases with secondary osteoarthritis were comparatively few and were mainly caused by pediatric hip disease. SRA might become an alternative for young men, but our follow up is too short to determine if this indication remains in the longer perspective.

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.

Introduction: Up to now comparisons and pooling of data between the Scandinavian arthroplasty registers have been restrained by use of separate and incompatible data systems.

Purpose: To create a common Scandinavian database for hip arthroplasties and to compare demographics and results between the Scandinavian countries.

Materials and methods: For this study we selected primary total hip prostheses (THR) from 1995–2006. A common code set was made, and after de-identification of the patients’ identity, including deletion of the national civil registration numbers, Denmark, Sweden, and Norway delivered data. Kaplan-Meier and Cox multiple regression, with adjustment for diagnosis, age, and gender, were used to calculate prosthesis survival, with any revision as end-point.

Results: 280,201 operations were included (Denmark 69,242, Sweden 140,821, Norway 70,138). Female patients constituted 60% in Denmark and Sweden and 70% in Norway. In Denmark, Sweden, and Norway childhood disease constituted 3.1%, 1.8%, and 8.7% respectively. The posterior approach was used in 91% of cases in Denmark, 60% in Sweden, and 24% in Norway. Cemented THRs were applied in 46% of patients in Denmark, 89% in Sweden, and in 79% in Norway. Resurfacing hips constituted 0.5% or less in all countries.

9,596 of the 280,201 primary THRs, had been revised. Ten-years survival was 91.9% (95% CI: 91.5 – 92.3) in Denmark, 93.9% (95% CI: 93.6–94.1) in Sweden, and 92.6% (95% CI: 92.3–93.0) in Norway.

In Sweden and Norway 23% of revisions were due to dislocation, compared to 34% in Denmark. Replacement of only cup or liner constituted 29% of the revisions in Sweden, 33% in Norway, and 44% in Denmark.

Conclusion: This unique database is now functioning, and has showed differences among the countries concerning demographics, prosthesis fixation, prosthesis survival, and reasons for revisions. The large number of THRs in this database significantly enhances our perspectives for future research, especially in diagnostic- and treatment groups with too small numbers in each separate

Background: Hemiarthroplasty of the hip is a common procedure, but information about implants and outcome is scarce. In Sweden the number of hemiarthroplasties has increased from 200 in 1998 to 4181 in 2007.

Material and Methods: Nationwide registration started in 2005. 100% of the hospitals participates, and 96% of the hemi-procedures are registrered. An analysis of 12 245 cases operated 2005–07 is presented.

Results: In the Register the mean age at surgery is 84 years (SD 7.0, 73% female). 93% are operated due to acute fracture and 6% due to failed internal fracture fixation. Cemented fixation has been used in 92% and a posterior approach in about half of the cases (52%). The Lubinus and Exeter stems are most common (41 and 23%). The Austin-Moore design has decreased from 9 to 2% during the study period.

3.2% of the patients (hips) have been reoperated, most commonly because of dislocation. Multiple reoperations are common. Male gender, secondary procedure and uncemented stem are associated with increased reoperation risk with 1.2, 1.7 and 1.8 times (1.2, CI: 1.0–1.6; 1.7, 1.3–2.3; 1.8 1.4–2.5). Use of uncemented fixation resulted in increased risk of reoperation, also with exclusion of uncemented Austin-Moore prostheses (1.8 times, 1.1–2.8).

In a separate analysis of the two most frequent designs, use of bipolar head increased the risk of revision twice (1.4–2.8) compared to unipolar head when adjusting for other risk factors. This may reflect that fitter and more active individuals get a bipolar prosthesis and are more prone to become revised should complications occur or a true increase of complications when using bipolar head. A further analysis is in progress.

Use of dorsal approach (1.6, 1.2–2.2), Austin-Moore (1.8, 1.1–3.1) and Thompson prostheses (1.8, 1.5–2.8) increased the risk of revision because of dislocation.

Summary: When treating fracture patients with hemi-arthroplasty we recommend that a well documented cemented implant with different off-set options should be used via an anterolateral approach. Use of bipolar heads may increase the risk of revision.

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.

INTRODUCTION: The postoperative periprosthetic femoral fracture is a severe complication after total hip surgery. It has become the third most common reason for revision. Three-hundred and twenty one fractures operated during 1999–2000, were followed in a prospective nationwide study. The study focused on the failure rate, patient satisfaction, treatment and radiographic evaluation.

PATIENTS AND METHODS: During 1999–2000, 230 fractures after a primary THR and 91 after a revision THR were reported to the Swedish National Hip Arthroplasty Register. All hospital records were collected. At follow-up the Harris hip score, a health-related quality of life measure (EQ-5D) and patient satisfaction were used as outcome measurement. A radiologist performed the radiographic evaluation.

RESULTS: A high number of patients had a loose implant at fracture time (66% in the primary group and 51% in the revision group). Eighty-eight percent of the fractures were classified as Vancouver type B fractures. A major finding was the association between the type of implant and the risk of a periprosthetic fracture. The Charnley and the Exeter prostheses were significantly over represented among patients with fractures and the Lubinus prosthesis significantly under represented. The surgeons grading of the Vancouver type B1 fracture was not in agreement with the study radiologist in more than 34% of the cases. Patient’s satisfaction concerning mobility, self-care, normal activities, pain and anxiety compared to an age matched population with a THR were poor. There was a high failure rate and by December 31, 2004, 22% had been reoperated.

DISCUSSION: A recommendation is to follow all THR patients with regularly radiographic monitoring and to intervene before the fracture. Implant related factors have to be considered when choosing implant for routine use. Difficulty in evaluating the x-rays concerning the stability of the prostheses might lead to sub optimal treatment. We recommend exploration of the implant for all patients with a Vancouver type B fracture if there is any doubt about the fixation status.