Few studies have compared the long-term survival of cemented primary total hip arthroplasties (THAs), and several prostheses have been used without adequate knowledge of their endurance. We studied long-term outcome based on data in the Norwegian Arthroplasty Register.
The 10 most used prosthesis brands in 62,305 primary Palacos or Simplex cemented THAs reported to the Register from 1987 through 2007 were included. Survival analyses with revision as endpoint (for any cause or for aseptic loosening) were performed using Kaplan-Meier and multiple Cox regression with time-dependent covariates. Revision rate ratios (RRs) were estimated for the follow-up intervals: 0-5, 6-10, and > 10 years.
5 prosthesis brands (cup/stem combinations) (Charnley, Exeter, Titan, Spectron/ITH, Link IP/Lubinus SP; n = 24,728) were investigated with 0-20 year follow-up (inserted 1987-1997). After 18 years, 11% (95% CI: 10.6-12.1) were revised for any cause and 8.4% (7.7-9.1) for aseptic loosening. Beyond 10 years of follow-up, the Charnley cup had a lower revision rate due to aseptic loosening than Exeter (RR = 1.8) and Spectron (RR = 2.4) cups. For stems, beyond 10 years we did not find statistically significant differences comparing Charnley with Titan, ITH, and SP stems, but the Exeter stem had better results (RR = 05). 10 prosthesis brands (9 cups in combination with 6 stems; n = 37,577) were investigated with 0-10 years of follow-up (inserted from 1998 through 2007). The Charnley cup had a lower revision rate due to aseptic loosening than all cups except the IP. Beyond 5 years follow-up, the Reflection All-Poly cup had a 14 times higher revision rate. For stems, beyond 5 years the Spectron-EF (RR = 6.1) and Titan (RR = 5.5) stems had higher revision rates due to aseptic loosening than Charnley. The analyses also showed a marked improvement in Charnley results between the periods 1987-1997 and 1998-2007.
We observed clinically important differences between cemented prosthesis brands and identified inferior results for previously largely undocumented prostheses, including the commonly used prosthesis combination Reflection All-Poly/ Spectron-EF. The results were, however, satisfactory according to international standards.
Cites: J Bone Joint Surg Br. 2003 Jan;85(1):45-5112585576
Cites: Bull Hosp Jt Dis. 1999;58(3):139-4710642863
Cites: J Bone Joint Surg Br. 2004 May;86(4):498-50315174542
Background and purpose - The bone cement market for total knee arthroplasty (TKA) in Norway has been dominated by a few products and distributors. Palacos with gentamicin had a market share exceeding 90% before 2005, but it was then withdrawn from the market and replaced by new slightly altered products. We have compared the survival of TKAs fixated with Palacos with gentamicin with the survival of TKAs fixated with the bone cements that took over the market. Patients and methods - Using data from the Norwegian Arthroplasty Register for the period 1997-2013, we included 26,147 primary TKAs in the study. The inclusion criteria were TKAs fixated with the 5 most used bone cements and the 5 most common total knee prostheses for that time period. 6-year Kaplan-Meier survival probabilities were established for each cement product. The Cox proportional hazards regression model was used to assess the association between bone cement product and revision risk. Separate analyses were performed with revision for any reason and revision due to deep infection within 1 year postoperatively as endpoints. Adjustments were made for age, sex, diagnosis, and prosthesis brand. Results - Survival was similar for the prostheses in the follow-up period, between the 5 bone cements included: Palacos with gentamicin, Refobacin Palacos R, Refobacin Bone Cement R (Refobacin BCR), Optipac Refobacin Bone Cement R (Optipac Refobacin BCR), and Palacos R?+?G. Interpretation - According to our findings, the use of the new bone cements led to a survival rate that was as good as with the old bone cement (Palacos with gentamicin).
Resurfacing of the patella during primary total knee arthroplasty (TKA) is often recommended based on higher revision rates in non-resurfaced knees. As many of these revisions are insertions of a patella component due to pain, and since only patients with a non-resurfaced patella have the option of secondary resurfacing, we do not really know whether these patients have more pain and poorer function. The main purpose of the present paper was therefore to assess pain and function at least 2 years after surgery for unrevised primary non-resurfaced and resurfaced TKA, and secondary among prosthesis brands.
Information needed to calculate subscales from the knee injury and osteoarthritis outcome score (KOOS) was collected in a questionnaire given to 972 osteoarthritis patients with intact primary TKAs that had been reported to the Norwegian Arthroplasty Register. Pain and satisfaction on visual analog scales and improvement in EQ-5D index score DeltaEQ-5D) were also used as outcomes. Outcomes were measured on a scale from 0 to 100 units (worst to best). To estimate differences in mean scores, we used multiple linear regression with adjustment for possible confounders.
We did not observe any differences between resurfacing and non-resurfacing in any outcome, with estimated differences of 0.4. There was, however, a tendency of better results for the NexGen implant as compared to the reference brand AGC for symptoms (difference = 4.9, p = 0.05), pain (VAS) (difference = 8.3, p = 0.004), and satisfaction (VAS) (difference = 7.9, p = 0.02). However, none of these differences reached the stated level of minimal perceptible clinical difference.
Resurfacing of the patella has no clinical effect on pain and function after TKA. Differences between the brands investigated were small and they were assumed to be of minor importance.
Cites: N Engl J Med. 2000 Apr 6;342(14):1016-2210749964
Patella resurfacing during primary total knee arthroplasty (TKA) is disputed and new prosthesis designs have been introduced without documentation of their survival. We assessed the impact on prosthesis survival of patella resurfacing and of prosthesis brand, based on data from the Norwegian Arthroplasty Register.
5 prosthesis brands in common use with and without patella resurfacing from 1994 through 2009 were included n = 11,887. The median follow-up times were 9 years for patella-resurfaced implants and 7 years for implants without patella resurfacing. For comparison of prosthesis brands, also brands in common use with only one of the two treatment options were included in the study population (n = 25,590). Cox regression analyses were performed with different reasons for revision as endpoints with adjustment for potential confounders.
We observed a reduced overall risk of revision for patella resurfaced (PR) TKAs, but the statistical significance was borderline (RR = 0.84, p = 0.05). At 15 years, 92% of PR and 91% of patella non resurfaced (NR) prostheses were still unrevised. However, PR implants had a lower risk of revision due to pain alone (RR = 0.1, p
Cites: Bull Hosp Jt Dis. 1999;58(3):139-4710642863
Cites: Arthritis Care Res (Hoboken). 2010 Apr;62(4):473-920391501
Impact of a Multifaceted and Clinically Integrated Training Program in Evidence-Based Practice on Knowledge, Skills, Beliefs and Behaviour among Clinical Instructors in Physiotherapy: A Non-Randomized Controlled Study.
Physiotherapists practicing at clinical placement sites assigned the role as clinical instructors (CIs), are responsible for supervising physiotherapy students. For CIs to role model evidence-based practice (EBP) they need EBP competence. The aim of this study was to assess the short and long term impact of a six-month multifaceted and clinically integrated training program in EBP on the knowledge, skills, beliefs and behaviour of CIs supervising physiotherapy students.
We invited 37 CIs to participate in this non-randomized controlled study. Three self-administered questionnaires were used pre- and post-intervention, and at six-month follow-up: 1) The Adapted Fresno test (AFT), 2) the EBP Belief Scale and 3) the EBP Implementation Scale. The analysis approach was linear regression modeling using Generalized Estimating Equations.
In total, 29 CIs agreed to participate in the study: 14 were invited to participate in the intervention group and 15 were invited to participate in the control group. One in the intervention group and five in the control group were lost to follow-up. At follow-up, the group difference was statistically significant for the AFT (mean difference = 37, 95% CI (15.9 -58.1), p
Cites: Tidsskr Nor Laegeforen. 2013 Aug 20;133(15):1587-9023970272
Over the decades, improvements in surgery and perioperative routines have reduced the incidence of deep infections after total hip arthroplasty (THA). There is, however, some evidence to suggest that the incidence of infection is increasing again. We assessed the risk of revision due to deep infection for primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 1987-2007.
We included all primary cemented and uncemented THAs reported to the NAR from September 15, 1987 to January 1, 2008 and performed adjusted Cox regression analyses with the first revision due to deep infection as endpoint. Changes in revision rate as a function of the year of operation were investigated.
Of the 97,344 primary THAs that met the inclusion criteria, 614 THAs had been revised due to deep infection (5-year survival 99.46%). Risk of revision due to deep infection increased throughout the period studied. Compared to the THAs implanted in 1987-1992, the risk of revision due to infection was 1.3 times higher (95%CI: 1.0-1.7) for those implanted in 1993-1997, 1.5 times (95% CI: 1.2-2.0) for those implanted in 1998-2002, and 3.0 times (95% CI: 2.2-4.0) for those implanted in 2003-2007. The most pronounced increase in risk of being revised due to deep infection was for the subgroup of uncemented THAs from 2003-2007, which had an increase of 5 times (95% CI: 2.6-11) compared to uncemented THAs from 1987-1992.
The incidence of deep infection after THA increased during the period 1987-2007. Concomitant changes in confounding factors, however, complicate the interpretation of the results.
The number of total knee replacements has substantially increased worldwide over the past ten years. Several studies have indicated a correlation between high hospital procedure volume and decreased morbidity and mortality following total knee arthroplasty. The purpose of the present study was to evaluate whether there is a correlation between procedure volume and the risk of revision following total knee arthroplasty with use of hospital volume data from the Norwegian Arthroplasty Register.
Thirty-seven thousand, three hundred and eighty-one total knee arthroplasties that were reported to the Norwegian Arthroplasty Register from 1994 to 2010 were used to examine the annual procedure volume per hospital. Hospital volume was divided into five categories according to the number of procedures performed annually: one to twenty-four (low volume), twenty-five to forty-nine (medium volume), fifty to ninety-nine (medium volume), 100 to 149 (high volume), and =150 (high volume). Cox regression (adjusted for age, sex, and diagnosis) was used to estimate the proportion of procedures without revision and the risk ratio (RR) of revision. Analyses were also performed for two commonly used prosthesis brands combined.
The rate of prosthetic survival at ten years was 92.5% (95% confidence interval, 91.5 to 93.4) for hospitals with an annual volume of one to twenty-four procedures and 95.5% (95% confidence interval, 94.1 to 97.0) for hospitals with an annual volume of =150 procedures. We found a significantly lower risk of revision for hospitals with an annual volume of 100 to 149 procedures (relative risk = 0.73 [95% confidence interval, 0.56 to 0.96], p = 0.03) and =150 procedures (relative risk = 0.73 [95% confidence interval, 0.54 to 1.00], p = 0.05) compared with hospitals with an annual volume of one to twenty-four procedures. Similar results were found when we analyzed two commonly used prosthesis brands.
In the present study, there was a significantly higher rate of revision knee arthroplasties at low-volume hospitals as compared with high-volume hospitals.
Despite the fact that there have been some reports on poor performance, titanium femoral stems intended for cemented fixation are still used at some centers in Europe. In this population-based registry study, we examined the results of the most frequently used cemented titanium stem in Norway.
11,876 cases implanted with the cemented Titan stem were identified for the period 1987-2008. Hybrid arthroplasties were excluded, leaving 10,108 cases for this study. Stem survival and the influence of age, sex, stem offset and size, and femoral head size were evaluated using Cox regression analyses. Questionnaires were sent to the hospitals to determine the surgical technique used.
Male sex, high stem offset, and small stem size were found to be risk factors for stem revision, (adjusted RR = 2.5 (1.9-3.4), 3.3 (2.3-4.8), and 2.2 (1.4-3.5), respectively). Patients operated in the period 2001-2008 had an adjusted relative risk (RR) of 4.7 (95% CI: 3.0-7.4) for stem revision due to aseptic stem loosening compared to the period 1996-2000. Changes in broaching technique and cementing technique coincided with deterioration of the results in some hospitals.
The increased use of small stem sizes and high-offset stems could only explain the deterioration of results to a certain degree since the year 2000. The influence of discrete changes in surgical technique over time could not be fully evaluated in this registry study. We suggest that this cemented titanium stem should be abandoned. The results of similar implants should be carefully evaluated.
Lung hyperinflation contributes to dyspnea, morbidity and mortality in chronic obstructive pulmonary disease (COPD). The inspiratory-to-total lung capacity (IC/TLC) ratio is a measure of lung hyperinflation and is associated with exercise intolerance. However, knowledge of its effect on longitudinal change in the 6-min walk distance (6MWD) in patients with COPD is scarce. We aimed to study whether the IC/TLC ratio predicts longitudinal change in 6MWD in patients with COPD.
This prospective cohort study included 389 patients aged 40-75?years with clinically stable COPD in Global Initiative for Chronic Obstructive Lung Disease stages II-IV. The 6MWD was measured at baseline, and after one and 3 years. We performed generalized estimating equation regression analyses to examine predictors for longitudinal change in 6MWD. Predictors at baseline were: IC/TLC ratio, age, gender, pack years, fat mass index (FMI), fat-free mass index (FFMI), number of exacerbations within 12?months prior to inclusion, Charlson index for comorbidities, forced vital capacity (FVC), forced expiratory volume in 1?s (FEV1), and light and hard self-reported physical activity.
Unicompartmental knee arthroplasty has received renewed interest; however, its short-term advantages over total knee arthroplasty should be weighed against a higher risk of reoperation. Information regarding pain and function after unicompartmental and total knee arthroplasty is therefore needed.
Patient-reported data regarding pain and function were collected, at least two years postoperatively and by way of postal questionnaire, from 1344 patients who were listed on the Norwegian Arthroplasty Register as having had an unrevised primary total knee arthroplasty (972 patients) or a unicompartmental knee arthroplasty (372 patients) for the treatment of arthritis. Outcomes were assessed (with a score of zero indicating the worst possible outcome and a score of 100 indicating the best possible outcome) with use of the five subscales from the Knee Injury and Osteoarthritis Outcome Score, the scores from visual analog scales regarding degree of pain and satisfaction with the surgery, and the change in index score (from preoperative to postoperative) on the EuroQol-5D health-related quality-of-life instrument. We also used all forty-two questions from the Knee Injury and Osteoarthritis Outcome Score as outcome measures. To be regarded as clinically significant, the differences needed to be eight units for the Knee Injury and Osteoarthritis Outcome Score outcomes, ten units for the pain and satisfaction scales, and 0.4 unit for the detailed Knee Injury and Osteoarthritis Outcome Score questions.
Unicompartmental knee implants performed better than total knee implants on the Knee Injury and Osteoarthritis Outcome subscales for "Symptoms" (adjusted mean difference, 2.7; p = 0.04), "Function in Daily Living" (adjusted mean difference, 4.1; p = 0.01), and "Function in Sport and Recreation" (adjusted mean difference, 5.4; p = 0.006). Of the forty-two analyses of the detailed questions, four differences were significant. These differences were in favor of unicompartmental knee arthroplasty, but only the question "Can you bend your knee fully?" reached the level of clinical significance.
We found only small or no differences in pain and function between the scores, at least two years following surgery, of patients who underwent unicompartmental knee arthroplasty and those of patients who underwent total knee arthroplasty; however, patients with unicompartmental knee implants had fewer problems with activities that involved bending the knee.