In order to emulate normal knee kinematics more closely and thereby potentially improve wear characteristics and implant longevity the Medial Pivot type knee replacement geometry was designed. In the current study the clinical and radiographic results of 50 consecutive knee replacements using a Medial Pivot type knee replacement are reported; results are compared to the Australian Orthopaedic Associations National Joint Replacement Registry. The patients' data were crossed checked against the registry to see if they had been revised elsewhere. After a mean follow-up of 9.96 years results show that the Medial Pivot Knee replacement provides good pain relief and functional improvement according to KSS and Womac scores and on subjective patient questionnaires. There was one minor revision; insertion of a patella button at 6.64 years FU. There were no major revisions; all implants appeared to be well fixed on standard radiographic examination. While the revision rate for the Medial Pivot knee according to the Australia Joint Registry results is higher compared to all other types of knee replacements in the registry, and to what is reported in the literature on the medial pivot knee, it is not in the current series. Revision rate was similar to what is reported on in the literature, but after a longer follow-up period. However, long term follow-up is required to draw definitive conclusions on the longevity of this type of implant.

Introduction: The Kudo total elbow prosthesis (TEP) is a well established implant, with good mid-term results. In the last decades this implant underwent several modifications. The last modification (type 5) has overcome the problems of stem breakage of the humeral component by modifications of the stem. The ulnar component can be placed with or without cement; the humeral component is always placed without cement.

Aims of this study: To examine the mid-term results of the Kudo type 5 TEP and to compare the results of the uncemented Kudo total elbow prosthesis (TEP), with the hybrid Kudo TEP (uncemented humeral component and cemented ulnar component).

Material and methods: Between 1994 and 2004 89 Kudo type 5 TEPs were placed for joint destruction due to rheumatoid arthritis (RA). The mean age of the patients was 55 years (range 21–84 years). Twenty-two prostheses were placed in males, 66 in females. Forty-nine TEPs (group 1) were fully uncemented and 40 TEPs (group 2) were hybrid (humeral component uncemented, ulnar component cemented). The groups were comparable as related to age, sex and indication for surgery. After implantation of the prosthesis a radiograph was made every two years or sooner when indicated.

Evaluation took place after an average of 5.3 years of follow up (range 1.7–10.6 years) and consisted of a questionnaire, elbow function assessment and anteroposterior and lateral radiographs in a standard way. Pre- and postoperative range of motion was analysed with the paired T-test. Pain scores and EFAS scores postoperatively were analysed using the independent sample T-test. The survival of the prosthesis was calculated from the time of implant to the time of revision or occurrence of radiolucencies.

Results: In group 1, seven ulnar components had to be revised due to aseptic loosening after a mean follow-up of 4 years (range 1.5–6.3 years). Three of these ulnar components were short-stemmed, four were long stemmed uncemented.

In group 2 five patients died of an unrelated course and no revisions have taken place, one TEP is loose on X-ray (after two years) with a suspicion of septic loosening The EFAS scores (87 in group 1 and 91 in group 2) and range of motion (84 degrees in group 1 and 90 degrees in group 2) were the same in both groups.

Conclusion: In this group of patients with RA the survival of the Kudo type 5 TEP with cemented ulnar component is better as compared to the uncemented ulnar component.