We examined the risk of thrombotic and major bleeding events in patients undergoing total hip and knee replacement (THR and TKR) treated with thromboprophylaxis, using nationwide population-based databases. We identified 83 756 primary procedures performed between 1997 and 2011. The outcomes were symptomatic venous thromboembolism (VTE), myocardial infarction (MI), stroke, death and major bleeding requiring hospitalisation within 90 days of surgery.

A total of 1114 (1.3%) and 483 (0.6%) patients experienced VTE and bleeding, respectively. The annual risk of VTE varied between 0.9% and 1.6%, and of bleeding between 0.4% and 0.8%. The risk of VTE and bleeding was unchanged over a 15-year period. A total of 0.7% of patients died within 90 days, with a decrease from 1% in 1997 to 0.6% in 2011 (p < 0.001). A high level of comorbidity and general anaesthesia were strong risk factors for both VTE and bleeding, with no difference between THR and TKR patients. The risk of both MI and stroke was 0.5%, which remained unchanged during the study period.

In this cohort study of patients undergoing THR and TKR patients in routine clinical practice, approximately 3% experienced VTE, MI, stroke or bleeding. These risks did not decline during the 15-year study period, but the risk of dying fell substantially.

Cite this article: Bone Joint J 2014;96-B:479–85.

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.

Background: A general increase in total number of primary total hip arthroplasty (THA) has been observed in Denmark from 3.828 in 1995 to 7.645 in 2006. During the same period the number of pa-tients treated at private clinics has also increased. To our knowledge no studies, comparing patient characteristics and treatment quality between public and private hospitals, have been published.

We compared patients’ characteristics and outcome following THA in private and public hos-pitals.

Materials and Methods: We used data from the Danish Hip Arthroplasty Registry to identify 69 249 primary THA’ies performed between 1 January 1995 to 31 December 2006.

To detect eventual difference in patient characteristics- age, gender, diagnosis leading to THA, Carlson’s comorbidity score and Charnley category were evaluated.

We matched 3 658 cases operated in private with 3 658 controllers operated in public hospitals on propensity score. Scoring parameters were age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis.

We used multivariate logistic regression on propensity score matched data to assess association between type of hospital and outcome by computing relative risks and 95% Confidence Interval (CI). Outcomes were perioperative complications, readmission within 3 months, re-operation within 2 years, implant failure after 5 years, and mortality within 3 months of surgery.

Results: Private hospitals operated on older females, patients with primary osteoarthritis and low comorbidity and Charnley category 1.

Patients in private and propensity matched controls from public hospitals showed no differences in age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis (p-value < 0,0001).

Based on matched data, private hospitals had lower relative risk for perioperative complications (0.39, 0.26–0.60), reoperations (0.59, 0.41–0.83) and readmissions (0.57, 0.42–0.77) compared with public. There was no difference in mortality or implant failure.

Discussion and Conclusions: We had no data on surgeon, general health and socioeconomic status of the patients. In addition, reported data from private clinics have not been validated in contrast to public hospitals

We found significant difference between patient characteristics operated at public versus private hospitals. No difference was evident regarding mortality and implant failure but for complications, reoperations and readmissions between private and public hospitals.

We have evaluated the extent to which diabetes affects the revision rate following total hip replacement (THR). Through the Danish Hip Arthroplasty Registry we identified all patients undergoing a primary THR (n = 57 575) between 1 January 1996 and 31 December 2005, of whom 3278 had diabetes. The presence of diabetes among these patients was identified through the Danish National Registry of Patients and the Danish National Drug Prescription Database. We estimated the relative risk for revision and the 95% confidence intervals for patients with diabetes compared to those without, adjusting for the confounding factors. Diabetes is associated with an increased risk of revision due to deep infection (relative risk = 1.45 (95% confidence interval 1.00 to 2.09), particularly in those with type 2 diabetes (relative risk = 1.49 (95% confidence interval 1.02 to 2.18)), those with diabetes for less than five years prior to THR (relative risk = 1.69 (95% confidence interval 1.24 to 2.32)), those with complications due to diabetes (relative risk = 2.11 (95% confidence interval 1.41 to 3.17)), and those with cardiovascular comorbidities prior to surgery (relative risk = 2.35 (95% confidence interval 1.39 to 3.98)).

Patients and surgeons should be aware of the relatively elevated risk of revision due to deep infection following THR in diabetes particularly in those with insufficient control of their glucose level.

Introduction: We examined the risk of blood transfusion in patients undergoing THA at 21 different orthopaedic departments in Denmark.

Material and Methods: Patients with primary THA (n=21,773) registered in the Danish Hip Arthroplasty Registry between 1999 and 2006 were identified. Data on use of blood transfusion was collected from the Danish Transfusion Data Base (DTDB). The outcome was defined as red blood cell transfusion (yes/no) within 7 days after surgery. Modified Poisson regression analyses were used to estimate the risk of red blood cells transfusion (RR) and a 95% confidence interval (CI) adjusting for possible confounding factors including patient related factors (age, gender, comorbidity and diagnosis for primary THA) and surgery related factors (type of anestesia, type of osiffication prophylaxis type of operation, duration of surgery, and duration of admission. The risk of blood transfusion for each department was compared with the general risk of blood transfusion for all departments.

Results: Overall, red blood cells transfusion was given to 8,162 of 21,773 patients (37%) (range between 16% and 64%, depending on department). After adjusting for different patient–and surgery-related factors, the adjusted RRs differed from 1.24 (95% CI, 2.07–3.43) to 0.52 (95% CI, 0.4–0.69) using all departments as reference. Coefficient of variation was 23%.

Conclusions: Substantial differences in the risk of red blood cells transfusion among THA patients were found when comparing a sample of Danish orthopaedic departments. The differences in use of transfusions appeared not to be explained by a range of patient – and surgery – related factors and may thus reflect true differences in transfusion practice.