Introduction: As a consequence of the rising prevalence of diabetes worldwide, an increasing proportion of diabetic THR patients may be expected in coming years. Diabetes research on postoperative complications among arthroplasty patients is limited. We evaluated the extent to which diabetes affect the revision rate due to aseptic loosening, deep infection and dislocation following total hip arthroplasty (THA).

Material and Methods: We used the Danish Hip Arthroplasty Registry (DHR) to identify all primary THR patients operated on during the period from 1 January 1996 to 31 December 2005. The presence of diabetes among THA patients was identified by using The Danish National Registry of Patients and The Danish National Drug Prescription Database. We used Poisson regression analyses, to estimate relative risk (RR) and 95% Confidence Interval (CI) for patients with diabetes compared to patients without diabetes, both crude and adjusted for potentially confounding factors.

Results: We identified 57 575 first primary THR patients in DHR, of which 3 278 (5.7%) were with diabetes and 54 297 (94.3%) without diabetes. An adjusted RR for revision due to deep infection of 1.45 (CI: 1.00–2.09) was found for THA diabetic patients compared to patients without diabetes. The RR was particularly high for THA patients with diabetes less than five years (RR was 1.71 (CI: 1.24–32.34), with the presence of diabetes related comorbidites prior THA (RR was 2.35 (CI: 1.39–3.98) and diabetes related complications (RR was 1.88 (CI: 1.17–3.03).

Conclusion. The patient and the surgeon should be aware of the relative increased risk of revision due to deep infection following THA as compared with the risk in THA patients without diabetes.

Aim: We determined 90 days mortality following primary total hip replacement (THR) and examined the impact of age and level of comorbidity.

Methods: We used data from the nationwide population based Danish Hip Arthroplasty Registry between 1 January 1995 and 31 December 2004. Each THR patient was matched according to gender and age on the time of surgery with 3 persons from the general population randomly sampled using the Danish Civil Registration system, resulting in a total of 44 818 THA patients and 120 883 controls. We used a Cox regression analyses to computed age and comorbidity specific mortality rates (MR) and mortality rate ratio (MRR) with 95% Confidence Intervals (CI) for THR patients compared with the general population, as well as Number Needed to Harm (NNH).

Results: The MRs for THR patients relative to those for the general population were highest in the patients younger than 60 years, corresponding to an adjusted MRR of 3.6 (95% CI: 2.2–5.5). Similar, an adjusted MRR was 1.2 (95% CI: 1.0–1.4) in patients aged 80 years and over. The THR patients younger than 60 years had more comorbidity than the controls, whereas distribution of comorbidity was equal in all other age groups. MRRs increase with comorbidity level for both THR patients and controls in all age groups. MRR for THR patients vs. controls within high comorbidity level aged below 60 years and aged 80 years and over was 3.5 (1.3–9.8) and 0.7 (0.5–0.9), respectively. However, hospitalisation with particularly cardio–og cerebrovasculaar disease before surgery increase mortality risk for both age groups, whereas hospitalisation with cancer increase mortality risk for patients younger than 60 years and decrease it for patients aged 80 years and over.

Conclusions: Overall mortality of THR patients relative to those in the general population was higher 90 days after surgery. Our findings apply particularly for THR patients aged 10 to 59 and 80 years and over. Although THR patients aged 80 years and over with high comorbidity level had lower mortality than corresponding persons from the general population, some particular groups of medical condition prior to surgery is associated with increased mortality risk whereas other medical conditions are associated with decreased mortality risk. We should be careful in making clinical decisions based on the Charslon comorbidity index; subgroups analyses may be necessary.

Further, we will present data on 90 days cause of death following primary THR and predictors for death, including age, gender and comorbidity (analyses are not finished yet).