Summary Objectives To evaluate implant survival following primary total hip replacement (THR) in younger patients. To describe the diversity in use of cup-stem implant combinations. Design 29,558 ...primary THRs osteoarthritis (OA) patients younger than 55 years of age performed from 1995 through 2011 were identified using the Nordic Arthroplasty Registry Association database. We estimated adjusted relative risk (aRR) of revision with 95% confidence interval (CI) using Cox regression. Results In general, no difference was observed between uncemented and cemented implants in terms of risk of any revision. Hybrid implants were associated with higher risk of any revision (aRR = 1.3, CI: 1.1–1.5). Uncemented implants led to a reduced risk of revision due to aseptic loosening (aRR = 0.5, CI: 0.5–0.6), whereas the risk was similar for hybrid and cemented implants. Compared with cemented implants, both uncemented and hybrid implants led to elevated risk of revision due to other causes, as well as elevated risk of revision due to any reason within 2 years. 183 different uncemented cup-stem implant combinations were registered in Denmark, of these, 172 were used in less than 100 operations which is similar to Norway, Sweden and Finland. Conclusions Uncemented implants perform better in relation to long-term risk of aseptic loosening, whereas both uncemented and hybrid rather than cemented implants in patients younger than 55 years had more short-term revisions because problems due to dislocation, periprosthetic fracture and infection has not yet been completely solved. The vast majority of cup-stem combinations were used in very few operations.
The Swedish Hip Register has defined the epidemiology of total hip replacement in Sweden. Most hip implants are fully cemented. Serious complications and rates of revision have declined significantly ...despite an increasing number of patients at risk. During the past 5 years, only 8-9% of hip replacements are revisions. Aseptic loosening with or without osteolysis is the major problem and constitutes 71% of the revisions, but the incidence had decreased three times during the past 15 years to less than 3% at 10 years. The effectiveness of the surgical technique is the most important factor for reducing the risk of revision because of aseptic loosening, but choice of implant is also important. In practice, total hip replacement in Sweden has improved, as judged by information from this Register about individualized patient risks, implant safety, and the greater efficacy of surgical and cementing techniques.
The Swedish Total Hip Replacement Register Malchau, Henrik; Herberts, Peter; Eisler, Thomas ...
Journal of bone and joint surgery. American volume,
01/2002, Letnik:
84, Številka:
suppl_2 Suppl 2
Journal Article
The Swedish National Total Hip Arthroplasty Register records primary hip replacements, revisions and surgical technique/environmental factors. The end-point for failure is revision. A prosthesis ...still in place, however, does not mean success. Clinical and radiographic outcomes should describe in more detail the efficacy of hip replacement surgery instead of the relatively blunt outcome measure that the register can provide. We performed a clinical outcome analysis on patients with primary total hip replacement thus testing the adequacy of the end-point for failure in the Swedish register. 1,113 randomly selected patients who had had total hip replacement surgery between 1986 and 1995 answered a diseasespecific self-administered questionnaire (WOMAC). A cohort of 344 patients was studied, using the Harris Hip Score and a conventional radiographic examination as outcome measures. We found clinical failure rates of 13% and 20% for all implants after 10 years, using 60 points or revision as the definition of failure in the Harris Hip Score and WOMAC, respectively. The result, according to the register during the same period, was a 7% revision rate. The clinical failure rate depended on the type of evaluation tool, definition of failure and demographics, which made it difficult to decide whether there was a need for revision. With the exception of pain measured by the Harris Hip Score, the results showed no significant correlation between clinical failure and radiographic failure. Hence, with the knowledge that there is a difference between the revision rate according to the register and clinical outcome, the strict definition of failure in the register is useful as an end-point for primary hip replacement surgery.
This survey focused on clinical reports of polyethylene wear and osteolysis in total hip replacements. With regard to documentation of clinical wear-rates, 57 publications were reduced to an analysis ...of 8 reports of THR series, including the incidence of osteolysis. A direct correlation was found among volumetric wear rates, incidence of osteolysis and revision rates in THR concepts of the 1983-1987 era. As volumetric wear rate increased, the incidence of osteolysis and revision rates increased. With regard to our grading system for volumetric wear, with follow-up in the 4-15 year range, osteolysis was rare in group A (wear = 0-80 mm 3 /year), ranging from 6% to 31% in group B (wear 40-80 mm 3 /year) and from 21% to 100% in group C (wear > 140 mm 3 /year). With regard to cup design, the optimal low-wear group had mainly cemented polyethylene cups with 22 and 28 mm head sizes. The mid-wear group B had metal-backed cemented and uncemented cups, with 28 mm head size, and the high-risk group C had only uncemented, metalbacked cups, with the highest wear in the 32 mm head size. Less than 10 years of follow-up did not distinguish adequately between different designs of THR, except in a few cases which had early failures due to material or design deficiencies. Overall, the cemented all-polyethylene cup combined with the smaller ball head proved to be better.
During the past 40 years, improvements have been made in the technique, implant, and surgical environment for total hip replacement, which today is one of the most cost-effective operations done. The ...aim of this study was to compare different outcome measurement methods and to develop recommendations for optimal followup of total hip replacement. The study involved the outcome of 2604 randomly selected patients in Sweden treated surgically with a modern technique. General questionnaires (the Medical Outcomes Study 36-Item Short-Form Health Survey and the Nottingham Health Profile) were compared with disease-specific questionnaires (the Western Ontario and McMaster University Osteoarthritis Index and the Harris hip score). The study showed a good correlation between the studied questionnaires, and all questionnaires used could be suitable for followup study after hip replacement surgery. In clinical practice and for research, a general and disease-specific self-administered score should be used. Some patients (older and low cerebral capacity) have difficulties answering questions on these questionnaires. A new short self-administered general and disease-specific questionnaire was designed: the Total Hip Replacement score. The Total Hip Replacement score provides information about the result of the hip arthroplasty, and the results can be compared with results of other surgical interventions.
Postoperative femoral periprosthetic fracture is an uncommon complication of total hip arthroplasty surgery, but several centers worldwide have recently reported an increase in total numbers of such ...fractures. This severe complication is costly for society and results in high morbidity. Our analysis of 1049 periprosthetic fractures occurring in Sweden between 1979 and 2000 and recorded in the Swedish National Hip Arthroplasty Register focuses on patient- and implant-related factors, fracture classification, and fracture frequency. These were our 3 major findings: (1) a majority of the patients who sustained a late periprosthetic femoral fracture had a loose stem. (2) Implant-related factors are significantly associated with occurrence of a periprosthetic fracture. (3) Since the 1980s in Sweden, treatment results for periprosthetic fractures have been poor, with low long-term survivorship and a high frequency of complications. We have initiated further studies of this important problem.
In work engaging the upper extremities, the musculoskeletal system of the shoulder is sometimes exposed to prolonged excessive load, leading to musculoskeletal disorders of the shoulder. One way of ...reducing work-related shoulder disorders is to establish guidelines for working postures. The purpose of this study was to identify harmful working positions, by performing a comprehensive survey of the intramuscular pressure (IMP) in the infra- and supraspinatus muscles in relation to different arm positions and external loads. Ten healthy males participated, and the IMP in the infra- and supraspinatus muscles was studied in a total of 112 combinations of arm positions and hand loads at levels that occur frequently in industrial work. High-precision spatial recordings were accomplished with a three-dimensional motion-analysis system, and the IMP was measured using the microcapillary infusion technique. The mean IMP of the infraspinatus muscle as well as that of the supraspinatus muscle increased continuously from a resting pressure at 0 degrees of upper arm elevation to a maximal pressure at 90 degrees of upper arm elevation, for all elevation planes. The mean IMP of the supraspinatus muscle appeared to be more dependent upon the elevation plane and less dependent upon the hand load, compared to the infraspinatus muscle. Even during only moderate arm elevation, the mean IMP of the infra- and supraspinatus muscles, presented here in polar diagrams, had already exceeded the levels of reduced recovery from local muscle fatigue and blood flow impairment. The elevation angle and the hand load primarily influence the development of IMP in the infra- and supraspinatus muscles.
The fixation of the femoral stem in a total hip arthroplasty was studied in sixty patients (sixty-four hips) with use of roentgen stereophotogrammetric analysis. The hips were randomly stratified on ...the basis of the age, sex, and weight of the patient; the roentgenographic quality of the bone; and the reason for the operation (primary or secondary osteoarthrosis). The hips were then randomly assigned to one of three types of fixation of the femoral componentinsertion with cement, hydroxyapatite coating, or porous coating. Examinations with roentgen stereophotogrammetry were done as long as two years after the operation. Micromotion of the prostheses was evaluated in terms of subsidence or proximal migration and rotations and translations of the proximal-lateral (shoulder) and distal (tip) parts of the prostheses. The clinical results at the two-year follow-up evaluation did not differ significantly between the groups with regard to the Harris hip score or the pain score (p > 0.05 for both; Wilcoxon rank-sum test). There were small or no differences in rotations and micromotions of the shoulder and the tip of the prostheses. Increased subsidence of 0.1 to 0.2 millimeter was recorded for the cemented and the porous-coated prostheses (p = 0.002 and p = 0.02, respectively; Wilcoxon rank-sum test). Thus, proximal hydroxyapatite coating seems to enhance the early fixation of the stem. Conventional roentgenography revealed an increased number of radiodense lines surrounding the porous-coated prostheses. Distal hypertrophy of the femoral cortex was found mainly around the hydroxyapatite-coated prostheses. Proximal resorption of bone and heterotopic ossification occurred to approximately the same extent regardless of the type of fixation used.
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