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The Bone & Joint Journal
Vol. 105-B, Issue 10 | Pages 1052 - 1059
1 Oct 2023
El-Sahoury JAN Kjærgaard K Ovesen O Hofbauer C Overgaard S Ding M

Aims

The primary outcome was investigating differences in wear, as measured by femoral head penetration, between cross-linked vitamin E-diffused polyethylene (vE-PE) and cross-linked polyethylene (XLPE) acetabular component liners and between 32 and 36 mm head sizes at the ten-year follow-up. Secondary outcomes included acetabular component migration and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension questionnaire, 36-Item Short-Form Health Survey, Harris Hip Score, and University of California, Los Angeles Activity Scale (UCLA).

Methods

A single-blinded, multi-arm, 2 × 2 factorial randomized controlled trial was undertaken. Patients were recruited between May 2009 and April 2011. Radiostereometric analyses (RSAs) were performed from baseline to ten years. Of the 220 eligible patients, 116 underwent randomization, and 82 remained at the ten-year follow-up. Eligible patients were randomized into one of four interventions: vE-PE acetabular liner with either 32 or 36 mm femoral head, and XLPE acetabular liner with either 32 or 36 mm femoral head. Parameters were otherwise identical except for acetabular liner material and femoral head size.


The Bone & Joint Journal
Vol. 104-B, Issue 2 | Pages 221 - 226
1 Feb 2022
Edwards NM Varnum C Nelissen RGHH Overgaard S Pedersen AB

Aims

The aim of this study was to examine whether socioeconomic status (SES) is associated with a higher risk of infections following total hip arthroplasty (THA) at 30 and 90 days.

Methods

We obtained individual-based information on SES markers (cohabitation, education, income, and savings) on 103,901 THA patients from Danish health registries between 1 January 1995 and 31 December 2017. The primary outcome measure was any hospital-treated infection (i.e. all infections). The secondary outcomes were further specified to specific hospital-treated infections (pneumonia, urinary tract infection, and periprosthetic joint infection). The primary timepoint was within 90 days. In addition, the outcomes were further evaluated within 30 days. We calculated the cumulative incidence, and used the pseudo-observation method and generalized linear regression to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for each marker.


The Bone & Joint Journal
Vol. 102-B, Issue 10 | Pages 1303 - 1310
3 Oct 2020
Kjærgaard K Ding M Jensen C Bragdon C Malchau H Andreasen CM Ovesen O Hofbauer C Overgaard S

Aims

The most frequent indication for revision surgery in total hip arthroplasty (THA) is aseptic loosening. Aseptic loosening is associated with polyethylene liner wear, and wear may be reduced by using vitamin E-doped liners. The primary objective of this study was to compare proximal femoral head penetration into the liner between a) two cross-linked polyethylene (XLPE) liners (vitamin E-doped (vE-PE)) versus standard XLPE liners, and b) two modular femoral head diameters (32 mm and 36 mm).

Methods

Patients scheduled for a THA were randomized to receive a vE-PE or XLPE liner with a 32 mm or 36 mm metal head (four intervention groups in a 2 × 2 factorial design). Head penetration and acetabular component migration were measured using radiostereometric analysis at baseline, three, 12, 24, and 60 months postoperatively. The Harris Hip Score, University of California, Los Angeles (UCLA) Activity Score, EuroQol five-dimension questionnaire (EQ-5D), and 36-Item Short-Form Health Survey questionnaire (SF-36) were assessed at baseline, three, 12, 36, and 60 months.


The Bone & Joint Journal
Vol. 98-B, Issue 3 | Pages 320 - 325
1 Mar 2016
Gundtoft PH Pedersen AB Schønheyder HC Overgaard S

Aims

The purpose of this study was to validate the diagnosis of periprosthetic joint infection (PJI) in the Danish Hip Arthroplasty Register (DHR).

Patients and Methods

We identified a cohort of patients from the DHR who had undergone primary total hip arthroplasty (THA) since 1 January 2005 and followed them until first-time revision, death, emigration or until 31 December 2012.

Revision for PJI, as registered in the DHR, was validated against a benchmark which included information from microbiology databases, prescription registers, clinical biochemistry registers and clinical records.

We estimated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PJI in the DHR alone and in the DHR when combined with microbiology databases.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 10 | Pages 1344 - 1350
1 Oct 2012
Penny JO Ding M Varmarken JE Ovesen O Overgaard S

Radiostereometric analysis (RSA) can detect early micromovement in unstable implant designs which are likely subsequently to have a high failure rate. In 2010, the Articular Surface Replacement (ASR) was withdrawn because of a high failure rate. In 19 ASR femoral components, the mean micromovement over the first two years after implantation was 0.107 mm (sd 0.513) laterally, 0.055 mm (sd 0.204) distally and 0.150 mm (sd 0.413) anteriorly. The mean backward tilt around the x-axis was -0.08° (sd 1.088), mean internal rotation was 0.165° (sd 0.924) and mean varus tilt 0.238° (sd 0.420). The baseline to two-year varus tilt was statistically significant from zero movement, but there was no significant movement from one year onwards.

We conclude that the ASR femoral component achieves initial stability and that early migration is not the mode of failure for this resurfacing arthroplasty.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 8 | Pages 1036 - 1044
1 Aug 2012
Penny JO Brixen K Varmarken JE Ovesen O Overgaard S

It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side.

Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group.

Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6).

On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups.

These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 2 | Pages 172 - 177
1 Feb 2011
Pedersen AB Baron JA Overgaard S Johnsen SP

We evaluated the short-term of 0 to 90 days and the longer term, up to 12.7 years, mortality for patients undergoing primary total hip replacement (THR) in Denmark in comparison to the general population. Through the Danish Hip Arthroplasty Registry we identified all primary THRs undertaken for osteoarthritis between 1 January 1995 and 31 December 2006. Each patient (n = 44 558) was matched at the time of surgery with three people from the general population (n = 133 674). We estimated mortality rates and mortality rate ratios with 95% confidence intervals for THR patients compared with the general population. There was a one-month period of increased mortality immediately after surgery among THR patients, but overall short-term mortality (0 to 90 days) was significantly lower (mortality rate ratio 0.8; 95% confidence interval 0.7 to 0.9). However, THR surgery was associated with increased short-term mortality in subjects under 60 years old, and among THR patients without comorbidity. Long-term mortality was lower among THR patients than in controls (mortality rate ratio 0.7; 95% confidence interval 0.7 to 0.7).

Overall, THR was associated with lower short- and long-term mortality among patients with osteoarthritis. Younger patients and patients without comorbidity before surgery may also experience increased mortality after THR surgery, although the absolute risk of death is small.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 10 | Pages 1303 - 1308
1 Oct 2006
Johnsen SP Sørensen HT Lucht U Søballe K Overgaard S Pedersen AB

We examined the association between patient-related factors and the risk of initial, short- and long-term implant failure after primary total hip replacement. We used data from the Danish Hip Arthroplasty Registry between 1 January 1995 and 31 December 2002, which gave us a total of 36 984 patients. Separate analyses were carried out for three follow-up periods: 0 to 30 days, 31 days to six months (short term), and six months to 8.6 years after primary total hip replacement (long term). The outcome measure was defined as time to failure, which included re-operation with open surgery for any reason.

Male gender and a high Charlson co-morbidity index score were strongly predictive for failure, irrespective of the period of follow-up. Age and diagnosis at primary total hip replacement were identified as time-dependent predictive factors of failure. During the first 30 days after primary total hip replacement, an age of 80 years or more and hip replacement undertaken as a sequela of trauma, for avascular necrosis or paediatric conditions, were associated with an increased risk of failure. However, during six months to 8.6 years after surgery, being less than 60 years old was associated with an increased risk of failure, whereas none of the diagnoses for primary total hip replacement appeared to be independent predictors.