All-polyethylene compared with metal-backed tibial components in total knee arthroplasty at ten years. A prospective, randomized controlled trial.

Background: Several studies have described equivalent performance on radiostereometric analysis at two years for metal-backed compared with all-polyethylene stemmed tibial implants. The purpose of this study was to determine the ten-year survivorship results of these two designs from a large randomized controlled trial.

Methods: Patients who were fifty years old or more, with no history of infection, and were undergoing primary total knee arthroplasty were randomized at the time of surgery to receive either an all-polyethylene or a metal-backed tibial component.

Do we need to replace the patella in knee arthroplasty for rheumatoid disease?

We have examined the anterior knee function in two patient groups who had undergone primary knee arthroplasty without patellar resurfacing to identify differences for osteoarthrosis compared with rheumatoid disease. We identified two consecutive series of patients who had undergone knee replacement surgery for either osteoarthritis or rheumatoid disease between 1992 and 1994 under the care of a single surgeon using the same implant and surgical technique. There were 90 patients in each group.

The role of the rotating hinge prosthesis in the salvage arthroplasty setting.

We have studied a consecutive series of 72 salvage knee procedures using a Kinematic rotating hinge prosthesis performed in a single arthroplasty unit between 1983 and 1997. Clinical and radiographic assessment of the survivorship of the Kinematic rotating hinge total knee arthroplasty (Howmedica, Rutherford, NJ) were analyzed. Survival analysis revealed a best-case 10-year implant survival of 90%.

284 press-fit Kinemax total knee arthroplasties followed for 10 years: poor survival of uncemented prostheses.

Background And Purpose: Our institution began using the Kinemax total knee arthroplasty system in 1988, both with and without cement fixation. We report 10-year survival figures.

Methods: Theater records showed that 284 Kinemax total knee arthroplasties had been performed 1988 through 1993.

Outcome following knee arthroplasty beyond 15 years.

There is a paucity of information detailing functional outcome following total knee arthroplasty for this length of follow-up. We collected data from 187 knees in 150 surviving patients, beyond 15 years from implantation. Survival of the implant was confirmed and a patient administered questionnaire including WOMAC, SF-36 and patient satisfaction was used, data was scrutinised for differences between primary and revision knee surgery.

Quality of life after knee revision arthroplasty.

Background And Purpose: Radiographic and clinical survival analyses of revision total knee replacement (TKR) are considered acceptable outcome measures. However, the full influence of revision knee replacement on the overall health status of patients remains poorly defined.

Methods: We prospectively studied the health-related quality of life outcome in 94 patients who underwent revision knee replacement surgery over a 5-year period.

A novel technique for the detailed size characterization of wear debris.

The accurate and detailed characterization of artificial joint wear debris is important in determining both the wear rate of prostheses and understanding the role that the debris plays in the development and progression of aseptic loosening. The novel application of low angle laser light scattering (LALLS) to the particle size characterization of ultra high molecular weight polyethylene (UHMWPE) wear debris is described. The results demonstrate that both ex vivo and in vitro origin wear debris samples, at concentrations typical of those produced via an alkali-digestion retrieval route, can be reproducibly analyzed via LALLS.

Role of abrasion of the femoral component in revision knee arthroplasty.

We carried out 60 revision procedures for failed porous coated anatomic total knee replacements in 54 patients, which were divided into two groups. The 14 knees in group I had a well-fixed femoral component at surgery which was retained, and in the 46 knees in group II both tibial and femoral components were loose and were revised using a variety of implants. Our review comprised clinical and radiological assessment.

Measured ambulation and self-reported health status following total joint replacement for the osteoarthritic knee.

Objective: To quantify the increase in ambulation produced by total knee replacement for osteoarthritis (OA) of the knee and to compare this with questionnaire-derived data.

Methods: We compared the measured ambulatory activity and self-reported Nottingham Health Profile (NHP) data of 19 subjects with OA of the knee before and after total knee replacement (TKR).

Results: Subjects were considerably restricted in their measured activity before operation compared with subjects with less severe disease.

Does body weight influence outcome after total knee arthroplasty? A 1-year analysis.

Obesity has been considered an adverse influence on the outcome of total knee arthroplasty (TKA), and overweight patients often are advised against having a TKA. The role of body weight has not been shown conclusively using objective outcome measures. A group of 180 patients undergoing primary TKA performed by a single surgeon for osteoarthritis was studied prospectively.

The effect of socket design, materials and liner thickness on the wear of the porous coated anatomic total hip replacement.

The wear of joint replacement prostheses represents the greatest challenge to their continued development. Parameters such as polyethylene quality, liner thickness and metal backing have all been implicated as potential detractors in the search for the lowest-wearing socket. This study examined the effect of these parameters through an extensive study of the two versions of the porous coated anatomic (PCA) hip prosthesis (one-piece socket and snaplock socket).

Postphlebitic syndrome after total knee arthroplasty: 405 patients examined 2-10 years after surgery.

We assessed the prevalence and relevance of putative risk factors for significant postphlebitic syndrome (PPS) in a cohort of 405 patients who underwent single limb cemented total knee arthroplasty. All patients were studied by means of a questionnaire and clinical examination to detect the presence of lower limb venous insufficiency. We found 52 (13%) new cases of postphlebitic syndrome.

Are clinical and patient assessed outcomes affected by reducing length of hospital stay for total hip arthroplasty?

This prospective observational study investigated the relationship between the length of hospital stay (LOS) and outcomes at 3 months for primary total hip arthroplasty for osteoarthritis. Mean length of postoperative stay was 9.5 +/- 2.

A comparison between cemented, press-fit, and HA-coated interfaces in Kinemax total knee replacement.

There are possible advantages of using uncemented fixation in total knee replacement. In this prospective randomised multi-centre study, a comparison was made between cemented and two types of uncemented fixation for the Kinemax design. There were 12-14 cases in each group.

The influence of femoral head surface roughness on the wear of ultrahigh molecular weight polyethylene sockets in cementless total hip replacement.

A theoretical relationship was recently proposed relating the wear behavior of polymetric bearing materials articulating against hard counterfaces.(1) This model attempts to predict the influence of surface roughness on wear. Laboratory-based studies have been used to establish the validity of these relationships, but their application to the clinical situation has not been investigated fully.

Health outcome after total knee replacement in the very elderly.

Between 1992 and 1994 we performed a prospective study of the effect of total knee replacement (TKR) on the health status of 119 patients over the age of 80 years who had had a primary unilateral TKR. The Nottingham Health Profile was used to assess this before and at three and 12 months after operation. We found a significant improvement in the scores for pain, emotional reaction, sleep and physical mobility at three months.

The frictional behaviour of explanted PCA hip prostheses.

The frictional characteristic of 22 explanted and two unused PCA total hip arthoplasties were assessed using the Durham hip simulator. The friction of the explanted joints was not found to be significantly different from that of the unused joints. In contrast, explanted Charnley joints often exhibit increased frictional characteristics.

Wear in retrieved acetabular components: effect of femoral head radius and patient parameters.

Forty-seven explanted Porous Coated Anatomic (PCA, Howmedica, Rutherford, NJ) cementless acetabular components were acquired at revision surgery. All the components articulated against CoCrMo femoral heads of 32-mm diameter. The penetration depth and angle were measured using the shadowgraph technique.

Kinematic condylar total knee arthroplasty. 14-year survivorship analysis of 208 consecutive cases.

We performed an independent survivorship analysis on 208 Kinematic Condylar knee replacements with a minimum follow-up of ten years and a mean of 12 years. Seven patients had been lost to follow-up. At ten years the estimated survival was 92% (95% confidence limits 95% and 87%) and when stratified for diagnosis and thickness of polyethylene there was no statistical difference (p > 0.

Survivorship analysis of the Kinematic Stabilizer total knee replacement: a 10- to 14-year follow-up.

The Kinematic Stabilizer is a posterior-cruciate-substituting design of total knee replacement. We have reviewed 109 primary total knee replacements in 95 patients at a mean follow-up time of 12.7 years (10 to 14).

Systemic release of cobalt and chromium after uncemented total hip replacement.

We measured the levels of cobalt and chromium in the serum in three groups of patients after uncemented porous-coated arthroplasty. Group 1 consisted of 14 consecutive patients undergoing revision for aseptic loosening. Group 2 comprised 14 matched patients in whom the arthroplasty was stable and group 3 was 14 similarly matched patients with arthritis awaiting hip replacement.

Results of uncemented porous-coated anatomic total hip replacement.

We reviewed a consecutive series of 241 uncemented, porous-coated anatomic (PCA) hip replacements at an average follow-up of five years (2 to 9). Of these, 32 had failed (13%), 26 at the acetabular component (11%) and six at the femoral component (2%). Acetabular failure was associated with local osteolysis and excessive polyethylene wear in 20 cases: in these histological examination showed giant macrophages incorporating numerous particles of high-density polyethylene.