Two types of national registers surveil infections after primary total hip arthroplasty (THA) in Norway: The National surveillance system for surgical site infections (NOIS) that surveil all primary THAs 30 days postoperatively for surgical site infections (SSI), and the Norwegian Arthroplasty Register (NAR) that follow all THAs until any surgical reoperation/revision or the death of the patient. Since these registers report on the same THAs we assessed correspondence between and time trends for the two registers in period 2013 to 2022. All reported THAs were included. The THAs were matched on a group level according to sex, age and ASA-class. In addition to descriptive statistics, adjusted Cox regression analyses were performed with adjustment for sex, age group (<45, 45-54, 55-64, 65-74, 75-84, >85 years) and ASA-class (1, 2, 3, 4 and missing). Changes in annual incidence and adjusted hazard rate (aHR) was calculated. Endpoints in the NOIS were 30-Days SSI and 30-Days reoperation for SSI. Endpoints in the NAR were 30-Days and 1-Year reoperation for periprosthetic joint infection (PJI).Aim
Method
The current recommendation in Norway is to use four doses of a first-generation cephalosporin (cefazolin or cephalotin) as systemic antibiotic prophylaxis (SAP) the day of surgery in primary joint arthroplasty. Due to shortage of supply, scientific development, changed courses of treatment and improved antibiotic stewardship, this recommendation has been disputed. We therefore wanted to assess if one dose of SAP was non-inferior to four doses in preventing periprosthetic joint infection (PJI) in primary joint arthroplasty. We included patients with primary hip- and knee arthroplasties from the Norwegian Arthroplasty Register and the Norwegian Hip Fracture Register for the period 2005-2023. We included the most used SAPs (cephalotin, cefazolin, cefuroxime, cloxacillin and clindamycin), administered as the only SAP in 1-4 doses, starting preoperatively. Risk of revision (Hazard rate ratio; HRR) for PJI was estimated by Cox regression analyses with adjustment for sex, age, ASA class, duration of surgery, reason for- and type of arthroplasty, and year of primary arthroplasty. The outcome was 1-year reoperation or revision for PJI. Non-inferiority margins were calculated for 1, 2 and 3 doses versus reference of 4 doses of SAP at the day of surgery, against a predetermined limit of 15% increased risk of PJI.Aim
Method
Previous publications have reported an increased but levelling out risk of revision for infection after total hip arthroplasty (THA) in Norway. We assessed the changes in risk of major (cup and/or stem, 1- or 2-stage) and minor revisions (debridement, exchange of modular parts, antibiotics and implant retention (DAIR)) for infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005-2022. Primary THAs reported to the NAR from 2005 to 2022 were included. Time was stratified into time periods (2005-2009, 2010-2018, 2019-2022) based on a previous publication. Cox regression analyses, adjusted for sex, age and ASA-classification, with the first revision for infection were performed.Background and purpose
Patients and methods
The Norwegian Arthroplasty Register (NAR) started collecting data on total hip arthroplasty (THA) in 1987. Very long-term results of implants for THA are scarce. We aimed to show long-term results for the three most used femoral stems, operated from 1987. We included the uncemented Corail femoral stem (n=66,309) and the cemented Exeter stem (n=35,050) both of which are currently in frequent use. In addition, we included the Charnley stem (n=32,578, in use until 2014). To ensure comparable conditions, stems fixated with low viscosity cement and stems revised due to infections were excluded. Differences in risk of revision (all reasons and stem revisions) were assessed with Kaplan-Meier and Cox regression analyses with adjustment for possible confounding from age, sex and diagnosis (OA, other). Stem revision was defined as a revision caused by loosening of the stem, dislocation, osteolysis in the femur, or periprosthetic femur fracture, and in which the femoral component was removed or exchanged. The median and max follow-up for Corail, Exeter and Charnley were 6.3 (33.1), 8.0 (34.2) and 13.1 (34.3) respectively. Thirty years survival estimates for Corail, Exeter and Charnley stems were 88.6% (CI:85.8–90.9%), 86.7% (83.7–89.2%) and 87.1% (85.4–88.5%) respectively with stem revision as endpoint, and 56.1% (CI:53.1–59.1%), 73.3% (70.5–76.1%) and 80.2% (78.4–82.0%) with all THA revisions as endpoint. Compared to the Corail, the Exeter (HRR=1.3, CI:1.2–1.4) and the Charnley (HRR=1.9, CI:1.7–2.1) had a significant higher risk of stem revision. Women 75 years and older had better results with the cemented stems. Analyses accounting for competing risk from other causes of revision did not alter the findings. The uncemented Corail stem performed well in terms of stem revisions for stem-related revision causes compared to two frequently used cemented stems with very long follow-up. The differences between the three stems were small.
Previous publications have suggested that the incidence of revisions due to infection after THA is increasing. We performed updated time-trend analyses of risk and timing of revision due to infection after primary THAs in the Nordic countries during the period 2004–2018. 569,463 primary THAs reported to the Nordic Arthroplasty Register Association from 2004 through 2018 were studied. We estimated adjusted hazard ratios (aHR) with 95% confidence interval by Cox regression with the first revision due to infection after primary THA as endpoint. The risk of revision was investigated. In addition, we explored changes in the time span from primary THA to revision due to infection.Aim
Methods
In recent years, many studies on We investigated the reported Aim
Methods
Young patients are at increased risk of revision after primary THA (THA). The bearing surface may be of importance for the longevity of the joint. We aimed to compare the risk of revision of primary stemmed cementless THA with MoM and CoC with metal-on-highly-crosslinked-polyethylene (MoXLP) bearings in patients between 20–54 years. From NARA, we included 2,153 MoM, 4,120 CoC and 10,329 MoXLP THA operated between 1995 and 2017. Kaplan-Meier estimator was used for calculation of THA survivorship and Cox regression to estimate the hazard ratio (HR) of revision (95% CI) due to any and specific causes. MoXLP was reference. The median follow-up was 10.3 years for MoM, 6.6 years for CoC and 4.8 years for MoXLP. 15 years postoperatively the Kaplan-Meier survival estimates were 80% (78–83%) for MoM, 92% (91–93%) for CoC and 94% (93–95%) for MoXLP. The 0–2, 2–7 and 7–15 years adjusted HRs of revision by any cause were 1.4 (0.9–2.4), 3.2 (2.1–5.1) and 3.9 (1.9–7.9) for MoM and 1.1 (0.8–1.4), 1.0 (0.7–1.3) and 2.5 (1.3–4.8) for CoC bearings. After 7–15 years follow-up, the unadjusted HR of revision due to aseptic loosening was 5.4 (1.2–24) for MoM and 4.2 (0.9–20) for CoC THA. MoM and CoC had a 7–15 year adjusted HR of revision due to ‘other’ causes of 4.8 (1.6–14) and 2.1 (0.8–5.8). MoXLP bearings were associated with better survival than MoM and CoC bearings, mainly because of lower risk of revision due to aseptic loosening and ‘other’ causes.
The aim of this study was to assess the influence of the true operating room (OR) ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA) reported to the Norwegian Arthroplasty Register (NAR). 40 orthopedic units were included during the period 2005 – 2015. The Unidirectional airflow (UDAF) systems were subdivided into small-area, low-volume, vertical UDAF (lvUDAF) (volume flow rate (VFR) (m3/hour) <=10,000 and diffuser array size (DAS) (m2) <=10); large-area, high-volume, vertical UDAF (hvUDAF) (VFR >=10,000 and DAS >=10) and Horizontal UDAF (H-UDAF). The systems were compared to conventional, turbulent ventilation (CV) systems. The association between revision due to infection and OR ventilation was assessed using Cox regression models, with adjustments for sex, age, indication for surgery, ASA-classification, method of fixation, modularity of the components, duration of surgery, in addition to year of primary THA. All included THAs received systemic, antibiotic prophylaxis.Aim
Method
Periprosthetic joint infection (PJI) after knee arthroplasty surgery remains a serious complication. Yet, there is no international consensus on the surgical treatment of PJI. The purpose was to assess the prosthesis survival rates, risk of re-revision, and mortality rate following the different surgical strategies (1-stage or 2-stage implant revision, and irrigation and debridement (IAD) with implant retention) used to treat PJI. The study was based on 653 total knee arthroplasties (TKAs) revised due to PJI in the period 1994 to 2016. Kaplan-Meier (KM) and multiple Cox regression analyses were performed to assess the survival rate of these revisions and the risk of re-revisions. We also studied the mortality rates at 90 days and 1 year after revision for PJI.Background
Methods
Periprosthetic osteolysis resulting in aseptic loosening is a leading cause for total hip arthroplasty (THA) failure. Individuals vary in their susceptibility to osteolysis, and it is thought that heritable factors contribute to this variation. We conducted two genome-wide association studies to identify genetic risk loci associated with osteolysis and genetic risk loci associated with time to prosthesis failure due to osteolysis. The Norway cohort comprised 2,624 subjects after THA recruited from the Norwegian Arthroplasty Registry, 779 with revision surgery for osteolysis. The UK cohort comprised 890 subjects recruited from hospitals in the north of England, 317 with radiographic evidence or revision surgery for osteolysis. All subjects had received a fully cemented or hybrid THA using small-diameter metal or ceramic-on-conventional polyethylene bearing. Osteolysis susceptibility case-control analyses and quantitative trait analyses for time to prosthesis failure were undertaken after genome-wide genotyping. Finally, a meta-analysis of the discovery datasets was undertaken.Introduction
Patients/Materials & Methods
There is an ongoing discussion on what bearing surfaces to use in different age groups of total hip replacement patients. We report results from uncemented total hip arthroplasty using ceramic on ceramic bearings reported to the Norwegian Arthroplasty Register in the period 1997–2014. Kaplan Meier and Cox regression analysis adjusting for age, gender and diagnosis was used to assess prosthesis survival at 10 and 15 years after primary operation and to report relative risk of revision. Endpoint was any revision. Comparison with the cemented Charnley prosthesis (n=17180), with metal-on-polyethylene articulations from the same time period was done. Results in age groups <55, 55–64, 65–74, >=75 were investigated. The following femur/cup combinations were used; Filler/Igloo (n=2590), Corail/Pinnacle (n=783), Corail/Duraloc (n=467), SCP Unique/Trilogy (n=363), Polar/R3 (n=253), ABGII/ABGII (n=131), other combinations (n=339). Alumina bearing was used in 3807 hips and Alumina-Zirconium composite bearings in 1119 hips. The overall ten and fifteen years unadjusted Kaplan Meier survivals were 94.8 % and 92.0 % respectively with no statistically significant difference between the brands. The cemented Charnley hip arthroplasty had 93.6 % survival at 15 years, and was not statistically significant different from the uncemented ceramic/ceramic group. The 10 years survival in the age groups <55, 55–64, 65–74, >=75 for the uncemented ceramic/ceramic group was 93.7%, 95.3%, 96.0% and 95.4% respectively with no difference between the uncemented brands and the cemented Charnley prosthesis. We found less revisions in patients >=75 in the Charnley group. In the ceramic on ceramic group 11 head fractures and 3 liner fractures were reported. The 15 years result of uncemented hip replacement with ceramic on ceramic bearing was good, and not different from the Charnley cemented arthroplasty in the age groups <75 years.
Systematic reviews disagree, but some recent studies have shown better function and less pain after operation with bipolar hemiarthroplasty compared to fixation by two screws in elderly patients operated for displaced femoral neck fractures. There is still uncertainty regarding the mortality associated with both procedures. To investigate mortality and the risk factors for death among patients with displaced femoral neck fractures within the first three years after surgery, comparing operation with bipolar hemiarthroplasty (HA) and internal fixation (IF) by two screws.Background
Aim of the study
Improving quality and efficiency is a priority in health policy. Several studies have shown a correlation between high hospital volume and improved results of surgery. In Norway, orthopaedic surgeons operate a relatively low number of total knee replacements compared with other countries. The number of total knee replacements has, however, increased significantly over the past 10 years. Some studies have also shown an association between surgeon volume and outcomes after total knee arthroplasty (TKA). We wanted to study a possible correlation between prosthesis survival and surgery volume of TKA, both with respect to hospital volume and surgeon volume.Background
Purpose
A well conducted randomised study found similar functional results for patients with displaced femoral neck fracture comparing operation with a modern uncemented bipolar hemiarthroplasty with a cemented bipolar hemiarthroplasty. The mortality associated with the two procedures has not been sufficiently investigated. To investigate the mortality and the risk factors for death among patients with displaced femoral neck fractures the first year after surgery, comparing operation with modern uncemented and cemented bipolar hemiarthroplasty (HA).Background
Aim of study
Displaced femoral neck fractures in elderly are normally treated with 2 screws/pins (IF) or bipolar hemiarthroplasty (HA). The aim of this study was to compare IF and HA as treatment for displaced femoral neck fractures using reoperations and functional result (patient satisfaction, pain, and quality of life) as outcome. From January 2005 all hip fractures in Norway are reported to the Norwegian Hip Fracture Register. At 4, 12, and 36 months postoperatively a questionnaire assessing satisfaction (VAS 0-100), pain (VAS 0-100), and quality of life (EQ-5D) is sent to the patients. To ensure more than 3 years follow-up, only patients operated in 2005 were included in the present study. Consequently 1,968 patients over 70 years of age operated with IF (n = 958) or HA (n = 1,010) due to displaced femoral neck fractures were included in the analyses on reoperations. Of these, 280 patients responded to all questionnaires and were included in the analyses on functional results (IF: n = 135, HA: n = 145). The patients remained in the same treatment group according to the intention-to-treat principle.Introduction
Material and Methods
Improving positioning and alignment by the use of computer assisted surgery (CAS) might improve longevity and function in total knee replacements. This study evaluates the short term results of computer navigated knee replacements based on data from a national register. Primary total knee replacements without patella resurfacing, reported to the Norwegian Arthroplasty Register during the years 2005–2008, were evaluated. The five most common implants and the three most common navigation systems were selected. Cemented, uncemented and hybrid knees were included. With the risk for revision due to any cause as the primary end-point, 1465 computer navigated knee replacements (CAS) were evaluated against 8214 conventionally operated knee replacements (CON). Kaplan-Meier survival analysis and Cox regression analysis with adjustment for age, sex, prosthesis brand, fixation method, previous knee surgery, preoperative diagnosis and ASA category were used.Background
Patients and Methods
Tranexamic acid (TA) in total knee replacement surgery (TKR) has shown marked reduction in bleeding and blood transfusion. There are little data on TA in revision TKR. From February 2008 all patients having primary or revision TKR received TA 10mg/kg × 2. We whished to evaluate the effect and possible complications of TA. 49 patients had revision TKR from January to August 2010. 21 patients (group I) operated before the regular use of TA were compared to 28 patients (group II) receiving TA. The groups were compared according to bleeding, blood transfusion, postoperative complication and type of revision. Revision TKR was compared to 157 primary TKR (94 operated without TA (group III) and 63 who received TA (group IV).Background
Patients and Methods
There are few studies of total knee replacements with cemented tibia and uncemented femur (hybrid). Previous studies have not shown any difference in revision rate between different fixation methods, but these studies had few hybrid prostheses. This study evaluates the results of hybrid knee replacements based on data from the Norwegian Arthroplasty Register (NAR). Primary total knee replacements without patella resurfacing, reported to the NAR during the years 1999–2009, were evaluated. Hinged-, posterior stabilized- and tumor prostheses were excluded. LCS- and Profix prostheses with conforming plus bearing were included. With the risk for revision at any cause as the primary end-point, 2945 hybrid knee replacements (HKR) were evaluated against 20838 cemented knee replacements (CKR). Kaplan-Meier survival analysis and Cox regression analysis with adjustment for age, sex and preoperative diagnosis were used.Background
Patients and Methods
The treatment of trochanteric and subtrochanteric fractures remains controversial, and new implants are constantly being developed trying to improve outcome and minimize the number of complications in these fractures. In Norway the Sliding Hip Screw(SHS), with or without a Trochanteric Stabilizing Plate (TSP), is still the most commonly used implant, but worldwide nailing of these fractures is increasing. This trend, however, has not been supported by documentation of better clinical results compared to the SHS in well designed studies. Therefore, in the present study we compared the recently launched Trigen Intertan nail (Smith and Nephew) with the SHS in the treatment of trochanteric and subtrochanteric fractures. In a prospective, randomized multicenter study with 697 patients, we compared the Trigen Intertan nail with the SHS regarding postoperative pain, functional mobility, complications, and reoperation rates. Patients older than 60 years with trochanteric and subtrochanteric fractures were included in 5 hospitals. At day 5, and 3 and 12 months postoperatively, pain was measured using a Visual Analogue Scale (VAS), and the Timed Up and Go-test (TUG-test) was performed to evaluate functional mobility. Complications and reoperations were recorded at discharge, and after 3 and 12 months.Introduction
Patients and Methods
