gms | German Medical Science

Objective: Total knee arthroplasty (TKA) is regarded as one of the most reliable surgical procedures in clinical orthopaedics. However, implant failure due to particle-induced aseptic loosening and hypersensitivity to metal ions still represent an emerging issue. Metal sensitivity in the general population is 10-20%, therefore, materials such as ceramics, which are bio-inert and with proven reduced wear, are of clinical interest.

Aim of this prospective international multi-centre study was to evaluate the clinical and radiological outcomes of an unconstrained TKA with a BIOLOX® delta ceramic femoral component.

Method: 107 patients (109 knees) underwent TKA with the cemented Multigen-Plus Ceramic Knee (Lima Corporate) at seven centres in three countries. Clinical and radiological assessments were carried out preoperatively, and postoperatively at 3, 12, 24 and 60 months, using HSS, WOMAC, SF-36 and standardised radiographs.

Results and conclusion: Mean HSS and WOMAC increased significantly from 55.1 ± 11.5 and 48.1 ± 16.6, respectively, preoperatively, to 85.6 ± 9.6 and 73.3 ± 20.4 at 60 months. Most improvement was seen in terms of pain relief and functional recovery. Mean SF-36 showed also a significant improvement in patients' quality of life (49.1 ± 17.6 preoperatively versus 67.7 ± 23.1 at 60 months).

Non-progressive radiolucent lines (<1 mm) were observed around the femoral component in four cases. Neither implant migration nor loosening were found. Six TKA revisions occurred: three due to infection, one due to arthrolysis and one implant failure as consequence of a patient traumatic fall. One revision was performed 5 years postoperatively in a hospital not included in the study. Hence it was not possible to acquire further data on this patient. Furthermore, four patients underwent reoperations without removal of the femoral component: two for retropatellar replacement, one for osteosynthesis consequent to a periprosthetic fracture after trauma and one for traumatic instability that required a change of polyethylene insert. Kaplan-Meier survivorship was 96% at 60 months (95% confidence interval).

Mid-term clinical and radiological outcomes of the Multigen-Plus Ceramic Knee are encouraging. 5-year implant survival rate is comparable to other unconstrained TKA systems. Therefore, ceramic knee implants represent a promising solution not only for patients with allergies against metallic components, but due to enhanced wear resistance, also for the general patient population with osteoarthritis. Further studies are necessary to assess long-term survivorship of Multigen-Plus Ceramic Knee.