Refobacin Bone Cement R and Palacos Overall, 75 patients were included in the study and 71 were available at two years postoperatively. Prior to surgery, they were randomized to one of the three combinations studied: Palacos cement with use of the Optivac mixing system, Refobacin with use of the Optivac system, and Refobacin with use of the Optipac system. Cemented MS30 stems and cemented Exceed acetabular components were used in all hips. Postoperative radiographs were used to assess the quality of the cement mantle according to Barrack et al, and the position and migration of the femoral stem. Harris Hip Score, Oxford Hip Score, Forgotten Joint Score, and University of California, Los Angeles Activity Scale were collected.Aims
Methods
In 1975, Sweden started registering primary knee replacement surgeries based on the personal identity number. Individual-based registrations of primary total hip replacements started in 1992 and for hemiarthroplasties the registration started in 2006. The completeness of these registrations is estimated at 98% during the last 10-year period. The long history and high completeness allow for accurate calculations of population-based prevalence of joint replacement and trends over time. We used all data on primary joint replacements available in the Swedish Arthroplasty Register. The prevalence was calculated using number of alive patients with 1) at least one joint replacement 2) at least one hip replacement 3) at least one knee replacement at the end of each year from 2010 – 2021. Publicly available population numbers were retrieved from Statistics Sweden. We calculated total prevalence and prevalence per age in years. By the end of 2021, 3.2% of the Swedish population had at least one hip or knee replacement. This was an increase from 2.5% in 2010. Among 80-year-old, the prevalence was 17.5% for any joint replacement. For both hip and knee replacement and all ages, the prevalence was higher for women. For knee replacement, the 2021 prevalence peaked at the age of 89 (9,4%) while the prevalence continuously increased with age for hip replacements. A considerable proportion of the Swedish elderly population is living with at least one hip or knee replacement. The prevalence has increased during the last 12-year period for both hips and knees. An increasing prevalence may also affect the incidence of fractures and infections. Knowledge about the prevalence is fundamental for planning future demand for primary and revision hip and knee replacement.
Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems. In total, 44 patients with bilateral hip osteoarthritis were recruited from the outpatient clinic at a single tertiary orthopaedic centre. The patients were operated with bilateral one-stage total hip arthroplasty. The most painful hip was randomized to either Fitmore or CLS femoral component; the second hip was operated with the femoral component not used on the first side. Patients were evaluated at three and six months and at one, two, and five years postoperatively with patient-reported outcome measures, radiostereometric analysis, dual-energy X-ray absorptiometry, and conventional radiography. A total of 39 patients attended the follow-up visit at two years (primary outcome) and 35 patients at five years. The primary outcome was which hip the patient considered to have the best function at two years.Aims
Methods
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
The aim of this study was to compare the mid-term patient-reported outcome, bone remodelling, and migration of a short stem (Collum Femoris Preserving; CFP) with a conventional uncemented stem (Corail). Of 81 patients who were initially enrolled, 71 were available at five years’ follow-up. The outcomes at two years have previously been reported. The primary outcome measure was the clinical result assessed using the Oxford Hip Score (OHS). Secondary outcomes were the migration of the stem, measured using radiostereometric analysis (RSA), change of bone mineral density (BMD) around the stem, the development of radiolucent lines, and additional patient-reported outcome measures (PROMs).Aims
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.
We evaluated an anatomical uncemented stem, SP-CL, (Static Physiologicus – CementLess) designed to facilitate insertion and to avoid stress concentration at solitary contact points in a randomized controlled trial, with use of the Corail stem as control. The SPÅ-Cl stem has been on the market since 2014 but is still not well documented. 79 patients (80 hips) were primarily recruited and 71 patients (72 hips, 36 SP-CL, 36 Corail) attended the last follow up at 2 years. The clinical evaluation included several types of PROMs with Oxford Hip Score (OHS) as primary outcome. In addition, repeated measurements of stem migration, changes in bone mineral density and development of radiolucencies were studied with RSA, DXA and conventional radiography. At two years the Oxford Hip Score did not differ between the SP-CL and Corail stem (estimated mean difference: −0.70 (95% CI: −4.28 – 2.89). In both groups Oxford hip score had almost doubled at 3 months, continued to increase up to 6 months and was about equal at 2 years (SP-CL; median 46 (17–48), Corail; median 47 (19–48)). At 2 years the SP-CL stems showed a median distal migration of −0.23 (−5.2 – 0.1) and the Corail stems of − 0.11 (−4.4 – 0.4). The SP-CL stems showed slightly more loss of bone mineral density in Gruen region 7 (p = 0.003). We found no difference in clinical results with use of either of the two stems. Bone mineral density loss tended to be higher with use of the SP-CL stem and the early subsidence tended to be more pronounced, which turned out to be compatible with about the same stem stability reached between 1 and 2 years. As a next step we think that the SP-CL stem should be studied in a multi-center setting, before accepted for general use.
We investigated patient characteristics and outcomes of Vancouver type B periprosthetic fractures treated with femoral component revision and/or osteosynthesis. The study utilized data from the Swedish Hip Arthroplasty Register (SHAR) and information from patient records. We included all primary total hip arthroplasties (THAs) performed in Sweden since 1979, and undergoing further surgery due to Vancouver type B periprosthetic femoral fracture between 2001 and 2011. The primary outcome measure was any further reoperation between 2001 and 2013. Cross-referencing with the National Patient Register was performed in two stages, in order to identify all surgical procedures not recorded on the SHAR.Aims
Patients and Methods
Aims
Patients and Methods
The primary purpose of the current study was to evaluate and compare the wear properties of vitamin E-doped, highly-crosslinked PE (VEPE) and one formulation of moderately cross-linked and mechanically-annealed ultra-high molecular weight PE (ModXLPE) in patients five years after primary THA. We also sought to understand whether polyethylene wear is associated with radiographic evidence of bone resorption or with deterioration in patient-reported outcome measures (PROMs). A total of 221 patients from four international centers were recruited into a prospective RSA and clinical outcomes study. Seventy percent (76%) of patients received VEPE (vs. ModXLPE) liners, and 36% received ceramic (vs. metal) femoral heads. PROMs and radiographs were collected preoperatively and at one, two, and five years postoperatively. In addition, RSA radiographs were collected to measure PE wear. We observed similar bedding in through the one-year interval and wear through the two-year interval between the two liner types. However, there was significantly more femoral head penetration in the ModXLPE cohort compared to the VEPE cohort at the five-year follow-up (p<0.001). The only variables independently predictive of increased wear were ModXLPE (vs VEPE) liner type (β=0.22, p=0.010) and metal (vs. ceramic) femoral head type (β=0.21, p=0.013). There was no association between increased wear and radiolucency development (p=0.866) or PROMs. No patients were found to have evidence of osteolysis. At five-years postoperatively, patients treated with VEPE (vs. ModXLPE) and ceramic (vs. metal) femoral heads demonstrated decreased wear. At the longest follow-up (five years postoperatively), the wear rates for both liner groups were very low and have not led to any osteolysis or implant failures via aseptic loosening.
The reported success rate after treatment with debridement, antibiotics and implant retention (DAIR) of hip prosthesis infections has been found variable. We evaluated all reoperations performed because of infection and reported to Swedish Hip Arthroplasty Register (SHAR) between 1999 and 2016. The analyses were separated into reoperations performed for the first time and those which had been preceded by at least one previous reoperation performed because of the same reason. The outcome was repeated reoperation performed because of infection. 1,882 were first-time procedures (Group I) and 2,275 had been preceded by at least one reoperation due to infection (Group II). Head and/or liner exchange had been performed in 47% of the cases in group I, and in 22% in Group II. The mean age varied between 70 and 71 years and there was a dominance of males in all groups (52–59%). Compared to all primary THR performed during this period (n=319,813) patients with inflammatory disease, idiopathic femoral head necrosis and sequel after childhood disease were overrepresented for this type of procedure. Between 1999 and 2016 the number of DAIR procedures increased from 29 to 383 per year corresponding to 21 and 72 % of all reoperations performed due to infection. In first time reoperations the survival was 74.5±3.1% if the head/liner had been exchanged and 46.2±3.2% if only irrigation and synovectomy had been performed. In patients reoperated at least one time previously due to infection the survival rates dropped to 68.6±4.6% and 34.5±2.4%. Compared to first time reoperation with exchange of femoral and/or liner, synovectomy and irrigation without exchange of any implant part(s) resulted in an almost tripled risk of a second reoperation due to same reason (Hazard Ratio: 2.8, 95% confidence interval: The comparatively good results observed after exchange of head and liner might indicate that this is necessary to perform a sufficiently radical debridement. This observation could also be biased by a surgeon related factor suggesting that component exchange mainly is performed by surgeons with long experience of revision surgery.
The Swedish Hip Arthroplasty Register started in 1979 and celebrates its 40th anniversary in 2019. The Swedish Hip Arthroplasty Register is not primarily a device register or research database; we strive to provide an overall assessment of the care provided with a multidimensional approach, and to disseminate knowledge on best practices in our network of participating hospitals. Since the inception of the register, there has been a marked change in trends and outcomes. The completeness of registrations has been 97–99% for primary THA, 93–95% for revisions, and 95–98% for HA over the last 10 years. The register contains 371,125 primary THAs, 55,893 HAs, 83,233 reoperations, and 408,110 PROM responses registered in 352,585 unique patients. All outcome measures have improved over time; primary THA has 0.71% 90-day mortality, 94.3% 10-year implant survival, and 2.2% 2-year reoperation rate. At 1-year follow up, 91% of the patients report a clinically significant pain reduction, 76% report a substantial improvement in health-related quality of life, and 89% are satisfied with the result of the operation. Moving forward, we are developing enhanced online applications for surgeons, patients and the implant industry to access real-time information. This work involves constructing a shared decision-making tool that helps clinicians assessing the future benefits and risks of THA by offering individualized outcome predictions. Further steps forward include randomized clinical trials and nested studies through the registry's platform. The trends and changes in Swedish arthroplasty practice have largely been promoted and facilitated by the register over the last 40 years.
Deep infection after THA is a devastating complication that implies major suffering for the patients and large costs for society. Reports from multiple national and regional registries show increasing incidence of deep infection. Is this a consequence of improved diagnostics, changed virulence of the causative organism, increased co-morbidity of the patients? An open database will be setup and hosted by an existing, high quality registry. All possible variables including patient demographic, detailed surgical information, bacteria/fungus characteristics, antibiotic treatment, radiographic findings and follow-up for 3 years will be collected. The incoming data will be displayed on a dashboard with continuous analyses and statistics. Any individual surgeon or hospital can report data. A board with members from the International Hip Society and the International Society of Arthroplasty Registries will supervise the process and facilitate scientific analyses from collected data.
We cross-matched the Swedish Hip and Knee Arthroplasty Registers (SHAR and SKAR) to study the incidence of knee or hip arthroplasty in any of the remaining hip or knee joints. 177835 THR (55.8% females, mean age, At the index operation more patients were operated on their right side for both locations (hip and knee). Patients who at the index operation had been operated with a TKR and especially on the left side most frequently (32.5%) received one or several additional TKR or THR. For patients who had a THR at their index operation and underwent a second operation of any of the remaining three joints the mean time to this second procedure was 4.0 years ( In patients who had undergone their first (index) operation of either hip the probability of not being subjected to further arthroplasty operations during the following 20 years amounted to 64.0±0.3%. The corresponding probability for patients who at the index operation had received a TKR was somewhat lower (58.4±0.4%). Decreasing age (HR: 1.029, 95% confidence interval: During our period of observation 25 to 33 percent of the patients who received their first total hip or knee replacement underwent at least one additional replacement of either the hip or the knee. Knee osteoarthritis more frequently results in staged bilateral joint replacement than in patients who primarily are suffering from osteoarthritis of the hip.
Osteolysis secondary to ultra-high molecular weight polyethylene (UHMWPE) wear is a leading cause of late-term implant failure via aseptic loosening in patients treated with total hip arthroplasty (THA). Radiation crosslinking of UHMWPE has been shown to decrease wear. However, the resulting polymer (crosslinked-PE) has a high free radical content. Two different methods that have been used to reduce the remaining free radicals are mechanical annealing and chemical stabilization using Vitamin E, a free radical scavenger. The primary purpose of the current study was to evaluate and compare the wear properties of vitamin E-doped crosslinked-PE (VEPE) and one formulation of mechanically annealed crosslinked-PE using radiostereometric analysis (RSA) in patients five years after primary THA. We also sought to understand the association between polyethylene wear and patient-reported outcome measures (PROMs). Three-hundred and five patients from six international centers were enrolled. Seventy-six percent were treated with highly-crosslinked (95 kGy) VEPE liners, and the rest received moderately-crosslinked (50 kGy) (ModXL), mechanically annealed liners. Data was collected prospectively at one-, two-, and five-year intervals. At the 5-year follow-up, proximal femoral head penetration into the VEPE liners (median = 0.05mm (range, −0.03–1.20)) was significantly lower than the penetration into the ModXL liners (median = 0.15mm (range, −0.22–1.04)) (p<0.001). In the VEPE cohort the median proximal penetration did not increase from one- to five-year follow-up (p=0.209). In contrast, there was a significant increase in femoral head penetration for the ModXL group (p<0.001) during that same time. Multivariable regression showed that the only variable predictive of increased wear was ModXL liner type (B=0.12, p<0.001). There were no differences in PROMs between the liner groups, and there was no correlation between polyethylene wear and PROMs for the cohort as a whole. The current study is the largest analysis of polyethylene wear at five-year follow-up using the RSA technique. We observed similar bedding in through the two-year interval between the two liner types, however, there was significantly more wear in the ModXL cohort at five-years. Currently, the wear rates for both liner groups are below the osteolysis threshold and have not led to any implant failures via aseptic loosening. Continued follow-up will provide a better understanding of the association between wear rate and clinical outcomes.
The aim of this study was to compare the incidence of aseptic
loosening after the use of a cemented acetabular component and a
Trabecular Metal (TM) acetabular component (Zimmer Inc., Warsaw,
Indiana) at acetabular revision with bone impaction grafting. A total of 42 patients were included in the study. Patients were
randomised to receive an all- polyethylene cemented acetabular component
(n = 19) or a TM component (n = 23). Radiostereometric analysis
and conventional radiographic examinations were performed regularly
up to two years post-operatively or until further revision.Aims
Patients and Methods
Prospectively collected data is an important source of information subjected to change over time. What surgeons were doing in 1999 might not be the case anymore in 2016 and this change in time also applies to a number of factors related to the performance and outcome of total hip replacement. We evaluated the evolution of factors related to the patient, the surgical procedure, socio-economy and various outcome parameters after merging the databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged with databases including general information about the Swedish population and about hospital care. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length of stay, mortality rate, adverse events, re-operation and revision rates and PROMs. Most patients were operated because of primary osteoarthritis and this share increased further during the period at the expense of decreasing number of patients with inflammatory OA and hip fracture. Comorbidity and ASA scores increased for each year. The share of all cemented implants has dropped from 92% to 68% with a corresponding increase of all uncemented from 2% to 16%. Length of stay decreased with about 50 percent to 4.5 days in 2012. The 30- and 90-day mortality rate dropped to 0.4% and 0.7%. Re-operation and revision rates at 2 years were lower in the more recent years. The postoperative PROMs are improving despite the preoperative pain scores getting worse. Even in Sweden, always been considered as a very conservative country with regards to hip replacement surgery, the demographics of the patients, the comorbidities and the primary diagnosis for surgery are changing. Despite these changes the outcomes like mortality, re-operations, revisions and PROMs are improving.
Infection after total hip arthroplasty (THA) is a devastating complication. With an ageing population and increased demands for THA, prosthetic joint infection (PJI) is expected to become an even greater problem in the future. In late PJI a one- or two-stage revision procedure is most often used. Factors determining the outcomes are not fully understood and there is controversy in the choice between the two methods. The, two-stage method in infected THA is regarded as more resource demanding and is associated with a high distress in the patients. The aim of this study was to compare the risk for second revision (re-revision) between one- and two-stage revision. During 1979–2015, 1659 first-time revisions performed due to infection were reported to the Swedish Hip Arthroplasty Register. Two-stage revision was the most common procedure (n=1255). Risk for a re-revision was compared between one- and two-stage revision using Cox-regression analysis adjusted for age, sex, diagnosis and method of fixation. The primary end-point was a re-revision regardless of cause. Aseptic loosening, infection, and dislocation necessitating re-revision were used as secondary outcomes. There was no difference in risk of re-revision regardless of cause (HR (one-stage/two-stage)=0.9, 95% C.I.=0.7–1.1, p=0.3), re-revision due to aseptic loosening (HR=1.1, 95% C.I.=0.7–1.6, p=0.7) or re-revision due to infection (HR=0.7, 95% C.I.=0.5–1.1, p=0.2). Dislocation necessitating a re-revision was less common in the one-stage group (HR=0.4, 95% C.I.=0.2–0.9, p=0.03). In this analysis re-revision rates were similar in the two groups. When analysed specifically for infection, risk of re-revision did not differ between one and two stage revision. Our findings confirm recent systematic reviews on the matter. This observational study supports increased utilisation of the one-stage approach. However prospective randomized studies are needed to validate these findings.
Compared with primary total hip arthroplasty (THA), revision
surgery can be challenging. The cement-in-cement femoral revision
technique involves removing a femoral component from a well-fixed
femoral cement mantle and cementing a new stem into the original
mantle. This technique is widely used and when carried out for the
correct indications, is fast, relatively inexpensive and carries
a reduced short-term risk for the patient compared with the alternative
of removing well-fixed cement. We report the outcomes of this procedure
when two commonly used femoral stems are used. We identified 1179 cement-in-cement stem revisions involving
an Exeter or a Lubinus stem reported to the Swedish Hip Arthroplasty
Register (SHAR) between January 1999 and December 2015. Kaplan-Meier
survival analysis was performed.Aims
Patients and Methods
It has been suggested that cemented fixation of total hip arthroplasty
(THA) is associated with an increased peri-operative mortality compared
with cementless THA. Our aim was to investigate this through a nationwide
matched cohort study adjusting for age, comorbidity, and socioeconomic
background. A total of 178 784 patients with osteoarthritis who underwent
either cemented or cementless THA from the Swedish Hip Arthroplasty
Register were matched with 862 294 controls from the general population.
Information about the causes of death, comorbidities, and socioeconomic
background was obtained. Mortality within the first 90 days after
the operation was the primary outcome measure.Aims
Patients and Methods
Stem revision with retention of the old cement mantle (cement-in-cement revision) in cases with an intact cement/bone interface is an appealing option. There has been an increasing use of this technique. In 2014 this cement-in- cement technique was used in 10% of all stem revisions reported to the Swedish Hip Arthroplasty Register (SHAR). We analysed the outcome of cement-in-cement stem revisions reported to the SHAR during years 2001–2014 Since 2001 1292 cement-in-cement revisions (study group), performed with a short (≤150 mm) Exeter stem (n=973) or a Lubinus stem (n=319) were reported to the SHAR. Stem revisions, using short Exeter and Lubinus stems without the use of the cement-in-cement technique (n=2893) acted as the control group in this analysis. Both groups were comparable regarding primary diagnosis. In the study group there were more females and the mean age (73 years) was 2 year older (p<0.001). The primary outcome was re-revision due to all causes (n=413). Re-revision of the stem due to all causes, infections excluded (n=212) was used as secondary outcome. Survival analysis using Kaplan-Meier was performed.Introduction
Patients/Materials & Methods
Dislocation as a primary cause of revision has been on the increase in Sweden (14% in 2014). The increasing use of Dual Mobility cups (DMC) could well be explained by the increased revision burden due to dislocation, patients undergoing revision having increased comorbidities and reports that dual articular cup designs reduce the risk of dislocation. The aim of this study was to analyze the change in utilization pattern of the dual articular designs used in acetabular revision surgery in Sweden. The short-term survival of DMC was compared to traditional designs. During years 2004–2014, 1111 (925 cemented) revisions performed with a DMC design were reported to SHAR. About half (n=426) of these cases were first time revisions performed due to dislocation. During the same time period 520 dislocations were revised for dislocation using a standard cemented cup. There was no differences regarding the age, gender and primary diagnosis (p≥0.12) between the two groups. A second cup revision for all reasons and specifically for dislocation was used as end-point. Kaplan-Meier analysis was performed.Introduction
Patients/Materials & Methods
We analysed impaction bone grafting used together with cemented or uncemented fixation in acetabular revision surgery. The overall risk for re-revision did not differ between the cemented and uncemented group. However, aseptic loosening was more common in the cemented group. Several surgical techniques address bone defects in cup revision surgery. Bone impaction grafting, introduced more than thirty years ago, is a biologically and mechanically appealing method. The primary aim of this study was to evaluate the effect of bone impaction grafting when used with uncemented and cemented fixation in cup revision surgery. Uncemented cups resting on more than 50% host bone were used as controls.Summary Statement
Background
Comparison of accuracy and precision in measuring wear using 4 commonly used uncemented cup designs shows small differences in mean and data scatter for marker and model-based RSA. The disadvantage with conventional RSA is that implant has to be supplied with tantalum markers, which may be difficult to visualise. This problem can be resolved with model-based RSA, but it is uncertain if this method has the same precision as marker-based RSA to measure wear. We compared these methods and studied different prosthesis geometries represented by four different uncemented cup designs (Trilogy, TMT-Trabecular Metal, Zimmer, Warsaw, USA, Ringloc, Biomet, Inc., Warsaw, Indiana, and ABG, Howmedica International, Staines, UK).Summary
Introduction
The effects of surgical approach in total hip
replacement on health-related quality of life and long-term pain
and satisfaction are unknown. From the Swedish Hip Arthroplasty
Register, we extracted data on all patients that had received a
total hip replacement for osteoarthritis through either the posterior
or the direct lateral approach, with complete pre- and one-year
post-operative Patient Reported Outcome Measures (PROMs). A total
of 42 233 patients met the inclusion criteria and of these 4962
also had complete six-year PROM data. The posterior approach resulted in
an increased mean satisfaction score of 15 ( Cite this article:
While an increasing amount of arthroplasty articles
report comorbidity measures, none have been validated for outcomes.
In this study, we compared commonly used International Classification
of Diseases-based comorbidity measures with re-operation rates after
total hip replacement (THR). Scores used included the Charlson,
the Royal College of Surgeons Charlson, and the Elixhauser comorbidity
score. We identified a nationwide cohort of 134 423 THRs from the
Swedish Hip Arthroplasty Register. Re-operations were registered
post-operatively for up to 12 years. The hazard ratio was estimated
by Cox’s proportional hazards regression, and we used C-statistics
to assess each measure’s ability to predict re-operation. Confounding
variables were age, gender, type of implant fixation, hospital category,
hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant
relationship with increased risk of re-operation, with increased
scores for both one to two and three or more comorbidities. However,
the predictive C-statistic in this period for the Elixhauser score
was poor (0.52). None of the measures proved to be of any value between
two and 12 years. They might be of value in large cohort or registry
studies, but not for the individual patient. Cite this article:
In medical research and among health-care providers there has been a marked shift to a focus on patient-reported outcome (PRO) and how it is measured and analysed. In this study from the Swedish Hip Arthroplasty Register we present the development and results of a nationwide, prospective, observational follow-up programme including patient-reported outcome measures (PROMs). The programme started in 2002 and has gradually expanded to include all units performing THA surgery in Sweden. The self-administered PROM protocol comprises the EQ-5D instrument, the Charnley categorization and visual analogue scales (VAS) for pain and satisfaction. These current analyses include 34 960 THAs with complete pre- and one-year postoperative questionnaires. Patients eligible for THA generally report low health-related quality of life (HRQoL) and suffer from pain. One year post-operatively the mean EQ-5D index increased from 0.41 to 0.78 (p<0.001) which is above the level of an age- and gender-matched population. Pain was reduced from mean VAS 62 to 14 (p<0.001). Females, younger patients and those with Charnley category C reported lower EQ-5D index pre-operatively than males, older patients and Charnley A or B, respectively, did (all p<0.001). In a multivariable regression analysis Charnley category C, male gender and higher age were associated with less improvement in HRQoL (p<0,001). Patients' response rates to the Registry was 86% pre-operatively and 90% one year post-operatively. Nationwide implementation of a PROM programme requires a structured organization and effective IT solutions. The continuous collection of PROs permits local and national improvement work and allows for further health-economic evaluation.
In Sweden approximately 6000 patients yearly sustain displaced femoral neck fractures. During the last decade there has been a shift towards more arthroplasties at the expense of internal fixation. In 2008 approximately 75% of the dislocated femoral neck fractures in Sweden were treated with arthroplasties. Those patients are typically elderly and frail and the vast majority of them receive hemiarthroplasties. In 2005 a national hemiarthroplasty registration was established as part of the Swedish Hip Arthroplasty Register (SHAR). The SHAR aims to register all hemiarthroplasties performed in Sweden, including primary and salvage procedures. Surgical and patient details are recorded and re-operations are registered.Background
Material & Method
We present the development and results of a nationwide, prospective, observational follow-up programme including patient-reported outcome measures (PROMs) for the Swedish Hip Arthroplasty Register. The programme started in 2002 and has gradually expanded to include all units performing total hip replacement in Sweden. The self-administered PROMs protocol comprises the EQ-5D instrument, the Charnley class categorisation and visual analogue scales for pain and satisfaction. These current analyses include 34 960 total hip replacements with complete pre- and one-year post-operative questionnaires. Patients eligible for total hip replacement generally report low health-related quality of life and suffer from pain. One year post-operatively the mean EQ-5D index increased to above the level of an age- and gender-matched population, with a considerable reduction of pain (p <
0.001). Females, younger patients and those with Charnley category C reported a lower EQ-5D index pre-operatively than males, older patients and Charnley category A or B, respectively (all p <
0.001). In a multivariable regression analysis Charnley category C, male gender and higher age were associated with less improvement in health-related quality of life (p <
0.001). Nationwide implementation of a PROMs programme requires a structured organisation and effective data capture. Patients’ response rates to the Registry are good. The continuous collection of PROMs permits local and national improvement work and allows for further health-economic evaluation.
Of 960 first-revision total hip replacements (THR) because of deep infection identified in the Swedish Hip Arthroplasty Registry, 16.9% were treated with a permanent implant extraction, while a staged or direct reconstruction revision protocol were employed in 56.2% and 26.9% respectively. The majority of the interventions were performed more than one year after index THR, and the dominating pathogen was coagulase negative staphylococci (CNS). We found a significant shift in types of bacteria over the years (Chi-square test, p smaller than 0.001): an increase in the CNS group and a decrease in Gram-negative aerobes. Patients treated with a permanent resection were generally older (p<
0.001), had more often a previous ipsilateral hip fracture (p<
0.001), and had more frequently Gram-negative infections (p=0.02). No systematic differences in patient characteristics or pathogens were detected between one-stage or two-stage procedures, of which the latter had a median re-implantation time of 2 (range: 0.2–62) months. Of 798 (one- or two-stage) revisions, 60 (7.5%) were revised again due to recurrent infection, with no difference between the two methods, and implying a 10-year survival of 90%; 95% confidence interval (CI95%) 88.2–93.0. Previous surgery for soft-tissue problems (RR 3.2 (CI95% 1.3–7.2)) predicted a worse outcome for one-stage procedures. The prognosis of two-staged revisions improved with increasing re-implantation interval (RR 0.8 (CI95% 0.7–1.0)) per month, and a 6 month interval carried the lowest risk of repeat revision due to infection; RR 0.1 (CI95% 0.0–0.9). Staged revisions in female patients (RR 2.3, (CI95% 0.9–5.7)) and with Staphylococcus aureus infections (RR 2.3 (CI95% 0.9–5.5)) predicted a worse outcome. Ten-year survival with repeat revision for aseptic loosening as end-point was 89% (95%CI 85.7–92.0), but decreased to 79% when all reasons for revision were taken into account (95%CI 75.0–82.3) mainly because of revision for peri-prosthetic fractures. The results suggest that direct and staged revision protocols can have a good prognosis on a national level, but efforts must be made to counteract periprosthetic fractures and the high incidence of permanent implant extraction in elderly patients.
3.2% of the patients (hips) have been reoperated, most commonly because of dislocation. Multiple reoperations are common. Male gender, secondary procedure and uncemented stem are associated with increased reoperation risk with 1.2, 1.7 and 1.8 times (1.2, CI: 1.0–1.6; 1.7, 1.3–2.3; 1.8 1.4–2.5). Use of uncemented fixation resulted in increased risk of reoperation, also with exclusion of uncemented Austin-Moore prostheses (1.8 times, 1.1–2.8). In a separate analysis of the two most frequent designs, use of bipolar head increased the risk of revision twice (1.4–2.8) compared to unipolar head when adjusting for other risk factors. This may reflect that fitter and more active individuals get a bipolar prosthesis and are more prone to become revised should complications occur or a true increase of complications when using bipolar head. A further analysis is in progress. Use of dorsal approach (1.6, 1.2–2.2), Austin-Moore (1.8, 1.1–3.1) and Thompson prostheses (1.8, 1.5–2.8) increased the risk of revision because of dislocation.
9,596 of the 280,201 primary THRs, had been revised. Ten-years survival was 91.9% (95% CI: 91.5 – 92.3) in Denmark, 93.9% (95% CI: 93.6–94.1) in Sweden, and 92.6% (95% CI: 92.3–93.0) in Norway. In Sweden and Norway 23% of revisions were due to dislocation, compared to 34% in Denmark. Replacement of only cup or liner constituted 29% of the revisions in Sweden, 33% in Norway, and 44% in Denmark.
In a previous report from a randomised study we reported excellent fixation and less proximal periprosthetic bone mineral loss around the Epoch design at 2 years follow-up when compared with a solid stem of similar design. We now present the 7 years follow-up. Forty consecutive patients (20 men, 10 women, mean age 57, 41–74) with non-inflammatory osteoarthritis were randomised to receive either a cementless porous-coated composite stem with reduced stiffness (Epoch) or a cementless stiff stem with a porous coating (Anatomic). Patients were followed for 7 years with repeated evaluations using radiostereometry, DXA, conventional radiography and Harris Hip Score (HHS). At 7 years 1 stem had been revised (Anatomic) due to late infection. Subsidence and stem rotations were close to zero without any difference between the two groups (p>
0,12). Median wear rates were lower than expected (0.4mm up to 7 years) for both stem designs. At 2 years loss bone mineral density was less in Gruen regions 1, 2, 6 and 7 for the Epoch stems (p<
0.04), but this difference tended to disappear with time. At 7 years only the calcar region (Gruen region 7) had significantly denser bone in the Epoch group (p<
0.001). The HHS scores did not differ (median 98, 51–100). No stem was radiographically loose. The Epoch stem achieved excellent fixation. Wear rates were low despite use of conventionally gamma-sterilised polyethylene. This low modulus stem had positive effects on early proximal bone remodeling, but this effect decreased with time.
Earlier reports have shown that surface treatment influences the survivorship of tapered hip implants. To assess the role of surface finish for other stem shapes we evaluated three modifications of the Lubinus SP2 stem. Eighty patients (31 male, 49 female, 68 (46–78 years), 84 hips) with non-inflammatory arthrosis randomly received either stem type: cemented matte (M, standard design), polymethylmetacrylate-coated (PC) or polished (P, collarless). Component fixation and wear were studied with radiostereometric analysis and the bone mineral density was measured around the stem in 40 patients at 6 months, 1, 2 and 5 years. The polished design showed increased distal migration at 6 months (Mean and range) P: −0.21mm(−0.52 to 0.09), M: −0.07mm (−0.34 to 0.26), PC: −0.03 (−0.18 to 0.18) and at 5 years P:0.49mm (−1.46 to 0.16), M: −0.18mm (−0.80 to 0.33), PC: −0.12mm (−1.40 to 0.12 (p<
0.0001). This increased subsidence occurred inside the cement mantle. The rotations of the stem did not differ (p>
0.4). Neither did the migration and the wear (p>
0.1). After 1 and 2 years the polished stems had lost significantly less bone mineral in Gruen zones 1, 2, 6 and 7 (p 0.004 to 0.03). After 5 years this difference had disappeared. The Harris Hip Scores did not differ. A polished surface without collar on an anteverted stem design resulted in increased subsidence of the stem inside the cement mantle. The improved bone remodeling around the polished version seemed to be transient.
Between 1999 and 2005, 10 264 patients who had undergone total hip replacement (THR) for subcapital fracture of the hip were compared with 76 520 in whom THR had been performed for other reasons. All the cases were identified through the Swedish Hip Arthroplasty Register. The THRs performed as primary treatment for fracture were also compared with those done after failure of internal fixation. After seven years the rate of revision was higher in THR after fracture (4.4% vs 2.9%). Dislocation and periprosthetic fracture were the most common causes of revision. The risk was higher in men than in women. The type of femoral component and the surgical approach influenced the risk. After correction for gender, type of component and the surgical approach the revision rates were similar in the primary and secondary fracture THR groups. Total hip replacement is therefore a safe method for both the primary and secondary management of fracture of the hip.
We have carried out a radiostereometric study of 50 patients (54 knees) with osteoarthritis of the knee who were randomly allocated to receive a cemented or a hydroxyapatite-coated femoral component for total knee replacement. The patients were also stratified to receive one of three types of articulating surface (standard, rotating platform, Freeman-Samuelson (FS)1000) all based on the Freeman-Samuelson design. The tibial components were cemented in all cases. Radiostereometry was performed post-operatively and at 3, 12 and 24 months. The analysis was restricted to rotation of the femoral component over time. After two years, rotation of the femoral components in the transverse, longitudinal and sagittal planes did not differ between the cemented and the hydroxyapatite-coated implants (p = 0.2 to 0.9). In total knee replacements with a rotating platform, the femoral component tended to tilt more posteriorly than in the other two designs, regardless of the choice of fixation (cemented or hydroxyapatite-coated, p = 0.04). The standard version of the femoral component, whether cemented or hydroxyapatite-coated, rotated more into valgus than was observed with the rotating-platform and FS1000 designs (p = 0.005). The increased constraint provided by the FS1000 component did not appear to have any adverse effect on fixation of the femoral component.
So far 15 patients, (6 male and 9 females) with a median age of 55 years (range 42–62) have been evaluated in group 1 and 14 (9 male and 5 females) with a median age of 55 years (range 45–70) in group 2. The penetration of the femoral heads has so far been measured postoperatively (all hips supine), after 3 month (17 hips supine and standing) and after 6 month (11 hips supine and standing) using radiostereometry.
1-year follow-up on approximately 50% of the patients will be presented at the meeting.
We studied the kinetics of the knee in 20 patients (22 knees) 12 months after total knee arthroplasty (TKA), by using three-dimensional radiostereometry and film-exchanger techniques. Eleven knees had a concave (constrained) tibial implant and 11 a posterior-stabilised prosthesis. Eleven normal knees served as a control group. In the posterior-stabilised knees there was less proximal and posterior displacement of the centre of the tibial plateau during extension from 45° to 15°, with a decrease in the anterior translation of the femoral condyles of 4 mm at 45°. There was less internal tibial rotation and increased distal positioning of the centre of the tibial plateau with both designs when compared with the normal knees, and in both the centre of the plateau was displaced posteriorly by more than 1 cm. Increased AP translation has been recorded in all prosthetic designs so far studied by radiostereometry. The use of a posterior-stabilised design of tibial insert could reduce this translation but not to that of the normal knee.
We analysed synovial fluid from 88 hips, 38 with osteoarthritis and 12 with well-functioning and 38 with loose hip prostheses. The levels of TNF-α, IL-1ß (71 hips) and IL-6 (45 hips) were measured using the ELISA technique. Joints with well-functioning or loose prostheses had significantly increased levels of TNF-α compared with those with osteoarthritis. Hips with aseptic loosening also had higher levels of IL-1ß but not of IL-6 compared with those without an implant. The levels of TNF-α and IL-1ß did not differ between hips with stable and loose prostheses. Higher levels of TNF-α were found in hips with bone resorption of type II and type III (Gustilo-Pasternak) compared with those with type-I loosening. The level of cytokines in joint fluid was not influenced by the time in situ of the implants or the age, gender or area of the osteolysis as measured on conventional radiographs. Our findings support the theory that macrophages in the joint capsule increase the production of TNF-α at an early phase probably because of particle load and in the absence of clinical loosening. Since TNF-α has an important role in the osteolytic process, the interfaces should be protected from penetration of joint fluid.
We revised 24 consecutive hips with loosening of the femoral stem using impaction allograft and a cemented stem with an unpolished proximal surface. Repeated radiostereometric examinations for up to two years showed a slow rate of subsidence with a mean of 0.32 mm (−2.0 to +0.31). Fifteen cases followed for a further year showed the same mean subsidence after three years, indicating stabilisation. A tendency to retroversion of the stems was noted between the operation and the last follow-up. Retroversion was also recorded when displacement of the stem was studied in ten of the patients after two years. Repeated determination of bone mineral density showed an initial loss after six months, followed by recovery to the postoperative level at two years. Defects in the cement mantle and malalignment of the stem were often noted on postoperative radiographs, but did not correlate with the degrees of migration or displacement. After one year, increasing frequency of trabecular remodelling or resorption of the graft was observed in the greater trochanter and distal to the tip of the stem. Cortical repair was noted distally and medially (Gruen regions 3, 5 and 6). Migration of the stems was the lowest reported to date, which we attribute to the improved grafting technique and to the hardness of the graft.
We enrolled 98 patients (107 hips) with a mean age of 47 years (SD 8.6) into a prospective study of the Madreporic Lord THR; 34 hips had primary and 73 secondary osteoarthritis. After ten years, the survival rate using revision as the endpoint for failure was 70% (±9) for the cup and 98% (±0.3) for the stem. The combined clinical and radiological survival rates were 46% (±11) and 81% (±10), respectively. Osteoporosis due to stress-shielding was observed in the proximal femur. Hips with radiologically dense bone postoperatively showed the most pronounced bone loss. We recommend continued radiological follow-up of patients with this type of implant to allow revision to be performed before there is severe bony destruction of the pelvis.