Arthroplasty implant registries over the past five decades: Development, current, and future impact.

Local, regional, and national registries have played an important role in the development of hip and knee arthroplasty and the treatment of patients with various maladies of these joints. Four arthroplasty registries stand out as leading forces behind the drive to popularize the use of registries and pursue the concept of evidence based medicine. The Mayo registry, started by Mark Coventry, is recognized as the oldest continuing registry for arthroplasty.

High proximal migration in cemented acetabular revisions operated with bone impaction grafting; 47 revision cups followed with RSA for 17 years.

Background: Bone impaction grafting is a biologically and mechanically appealing option in acetabular revision surgery, allowing restitution of the bone stock and restoration of the biomechanics. We analysed differences in proximal migration of the revision acetabular components when bone impaction grafting is used together with a cemented or an uncemented cup.

Patients And Methods: 43 patients (47 hips), revised due to acetabular loosening and judged to have less than 50% host bone-implant contact were included.

Association between fixation technique and revision risk in total hip arthroplasty patients younger than 55 years of age. Results from the Nordic Arthroplasty Register Association.

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.

Stable fixation but unpredictable bone remodelling around the Lord stem: minimum 23-year follow-up of 66 total hip arthroplasties.

Early designs of uncemented hip implants turned out to be failures mainly because the prerequisites for durable implant fixation were unknown. One exception was the chrome-cobalt stem of the Madreporic Lord prosthesis. We prospectively studied this prosthetic design in 107 hips that underwent surgery in 1979-1986.

Highly crosslinked polyethylene does not reduce aseptic loosening in cemented THA 10-year findings of a randomized study.

Background: Polyethylene (PE) wear particles are believed to cause aseptic loosening and thereby impair function in hip arthroplasty. Highly crosslinked polyethylene (XLPE) has low short- and medium-term wear rates. However, the long-term wear characteristics are unknown and it is unclear whether reduced wear particle burden improves function and survival of cemented hip arthroplasty.

The Nordic Arthroplasty Register Association: a unique collaboration between 3 national hip arthroplasty registries with 280,201 THRs.

Background And Purpose: The possibility of comparing results and of pooling the data has been limited for the Nordic arthroplasty registries, because of different registration systems and questionnaires. We have established a common Nordic database, in order to compare demographics and the results of total hip replacement surgery between countries. In addition, we plan to study results in patient groups in which the numbers are too small to be studied in the individual countries.

5-year experience of highly cross-linked polyethylene in cemented and uncemented sockets: two randomized studies using radiostereometric analysis.

Background: Laboratory tests and early clinical studies have shown that highly cross-linked polyethylene (PE) markedly improves wear resistance compared to conventional PE. We evaluated this type of PE in two randomized clinical studies using radiostereometric analysis (RSA). The 2- and 3-year follow-up of these studies have already been reported.

Standardized incidence rates of total hip replacement for primary hip osteoarthritis in the 5 Nordic countries: similarities and differences.

Background: The national hip registers of the Nordic countries provide an opportunity to compare age- and sex-standardized annual incidence of primary total hip replacement (THR) and types of implants used for primary hip osteoarthritis (OA) in Denmark, Finland, Iceland, Norway and Sweden.

Methods: The data on THR were from the national total hip replacement registries, and population data were from the national statistics agencies. Annual incidence density per 100,000 was calculated for each 5-year age group and it was age-standardized using the WHO European standard population.

Three hundred and twenty-one periprosthetic femoral fractures.

Background: The purpose of this study was to determine the demographics, incidence, and results of treatment of periprosthetic fractures in a nationwide observational study.

Methods: In the years 1999 and 2000, 321 periprosthetic fractures were reported to the Swedish National Hip Arthroplasty Register. All of the associated hospital records were collected.

Presidential guest address: the Swedish Hip Registry: increasing the sensitivity by patient outcome data.

The Swedish Hip Register was initiated in 1979. The mission of the register is to improve the outcome of THA. The hypothesis is that feedback of data stimulates participating clinics to reflect and improve.

Periprosthetic femoral fractures classification and demographics of 1049 periprosthetic femoral fractures from the Swedish National Hip Arthroplasty Register.

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.

The Otto Aufranc Award. Highly cross-linked polyethylene in total hip arthroplasty: randomized evaluation of penetration rate in cemented and uncemented sockets using radiostereometric analysis.

The annual wear rate in polyethylene articulations should be 0.1 mm or less to avoid future osteolysis. Highly cross-linked polyethylene shows an 80 to 90% wear reduction in hip simulator testing, but the clinical documentation of this new polyethylene is still inadequate.

Radiographic evaluation of Charnley cups used in first-time revision: repeated observations for 7-15 years.

The radiographs of 46 consecutive polyethylene cups used in cemented first-time revision of the acetabulum were studied up to a mean of 10.7 years (range, 0.5-16.

Cemented first-time revision using Charnley cups: clinical outcome after 7 to 15 years follow-up.

Forty-six consecutive polyethylene cups used in cemented first-time revision of the acetabulum were evaluated at repeated occasions up to mean 10.7 years (range, 0.5-16.

Highly cross-linked polyethylene in cemented THA: randomized study of 61 hips.

Highly cross-linked polyethylene (PE) has been introduced as an alternative bearing material in total hip arthroplasty (THA) because of high wear resistance in laboratory tests but the clinical experience of this material is limited. We evaluated a highly cross-linked PE (warm irradiated adiabatic melting, absorbed dose, 95 kGy) in a randomized study of cemented THAs. Cups of the same design but made of conventionally gamma irradiated PE (absorbed dose, 25-40 kGy) constituted the control group.

Kinematics of three variations of the Freeman-Samuelson total knee prosthesis.

The effect of changes in the articulating surfaces on the kinematics of the Freeman-Samuelson total knee replacement was evaluated. Twenty-two patients (22 knees) (median age, 69 years) were randomized to a standard design with a fixed polyethylene bearing, a design with a mobile bearing, or a new design with a spherical medial femoral condyle with a fixed bearing. The patients were studied with radiostereometry and film-exchangers at 0 degrees nonweightbearing and during active weightbearing extension from 45 degrees to 15 degrees.

Evaluation of a femoral stem with reduced stiffness. A randomized study with use of radiostereometry and bone densitometry.

Background: Femoral stems with reduced stiffness were introduced in total hip arthroplasty to facilitate proximal load transfer and thereby reduce periprosthetic bone loss. Poor fixation and unacceptably high revision rates turned out to be a major problem with these prostheses. The purpose of the present study was to evaluate the early performance of a low-modulus stem (one that is less stiff) with the potential to address the problem of fixation by the use of a surface coating.

A low stiffness composite biologically fixed prosthesis.

The current authors addressed the question whether stress-induced adaptive bone remodeling of the proximal femur is a necessary consequence after total hip reconstruction with extensively biologically-fixed femoral components. A novel total hip femoral component was designed to simultaneously achieve stable skeletal fixation, structural durability, and reduced femoral stress shielding. This implant allowed for proximal and distal canal filling, yet was significantly less rigid than all-metallic femoral stems crafted of either cobalt chromium or titanium alloy.

Charnley cups retained during revision of the femoral component: repeated clinical and radiographic observations of 49 cups for 7-15 years.

This article concerns 49 consecutive polyethylene cups retained in cemented first revisions of the femoral component and evaluated on several occasions 7-15 years after the index operation. At the last follow-up 5 cups were revised, 3 were radiographically loose, 1 was revised because of recurrent dislocation and 1 stable cup was revised because the surgeon wished to use a 28 mm head. Moreover, 1 unrevised cup was radiographically loose.

Outcome of total hip replacement: a comparison of different measurement methods.

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.

Outcome after total hip arthroplasty: Part II. Disease-specific follow-up and the Swedish National Total Hip Arthroplasty Register.

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.

Correlation of wear debris-induced osteolysis and revision with volumetric wear-rates of polyethylene: a survey of 8 reports in the literature.

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.

In vivo kinematics of total knee arthroplasty: flat compared with concave tibial joint surface.

This study evaluated the influence of the geometric configuration of the tibial joint area on the kinematics of the knee. Twenty-two patients with noninflammatory arthritis and minor preoperative deformity were studied. They each received an AMK total knee replacement with retention of the posterior cruciate ligament.