THE SHORT TERM CLINICAL AND RADIOLOGICAL FOLLOW UP OF 91 NAVIGATED UNCEMENTED ROTATING PLATFORM TKA

Abstract

Uncemented total knee arthroplasty (TKA) implants were designed as an alternative to cemented implants. However, critical studies revealed a unique set of complications. At the same time, cemented prostheses continue to yield excellent results. To address some of the issues with uncemented implants, porous coatings were introduced. This follow-up study reports the early results of Plasmapore^® coating in Navigated uncemented rotating platform TKA.

277 patients who had consecutively undergone a Navigated TKA procedure with the e.motion knee endoprostheses were followed up at the Bluespot Knee Clinic in Blackpool, UK. Of these 277 patients, 91 received an uncemented TKA between May 2005 and September 2007. The prosthesis is coated with a 350μm plasma-sprayed titanium layer. All procedures were carried out by the senior author (SACS). The Orthopilot navigation system was used to accurately restore the axial alignment of the implants.

Men comprised 51% and women 49%. The mean age was 69 years and the mean BMI was 30. There were 50 right and 41 left knees. The mean operating time was 59 minutes. Of the 91 patients who received an uncemented e.motion TKA, 84 patients had at least 1 follow-up assessment. The average follow-up period for these 84 cases was 7 months. The integrated Knee Society Score (KSS) defined as the sum of functional and clinical KSS, was recorded for all 91 patients preoperatively and had a mean of 78. The KSS had increased to 182 after 4 months, 193 after 1 year and 198 after 2 years. Oxford score was recorded for 87 of the 91 patients preoperatively. The average preoperative score was 44. It had decreased to 18 after 4 months, and 16 after 1 year and 13 after 2 years.

Radiological examination showed no evidence of periprosthetic lucency and no subsidence.

There were 5 DVTs with 2 pulmonary embolisms, 2 cases of reflex sympathetic dystrophy, 2 stitch abscesses, 2 haematomas, and 9 cases of wound erythema. These preliminary findings compare favourably with published series of cemented TKAs. They have prompted a more detailed review which is in progress.