Cementless total knee arthroplasty in chronic inflammatory rheumatism

Abstract

Introduction: We report a short-term monocentric retrospective evaluation of cementless total knee arthroplasty (TKA) in a population suffering from chronic inflammatory rheumatism.

Materials and methods: We have reviewed 23 patients (34 knees) with an average age of 55 years (range 26-78), bearing a TKA for chronic inflammatory rheumatisms with a 6-year follow-up (range 3-12); 78% suffered from rheumatoid arthritis and 15% from juvenile rheumatoid arthritis. We used a cementless total prosthesis sacrificing the posterior cruciate ligament and bearing an ultra-congruent rotational tibial insert, the Natural Knee (NK2™) (Zimmer(®), Warsaw, IN, USA). At last follow-up, an independent surgeon performed a clinical assessment for pain, function and quality of life using International Knee Documentation Committee score, International Knee Society (IKS) score and Devane's score. A radiographic study evaluated secondary fixation according to the radiographic index of the Knee Society and according to Ewald's score.

Results: The mean postoperative IKS score was 83 points (range 40-100) for the knee score and 74 points (range 20-100) for the function score. Radiographic assessment came across only one case of loosening, concerning the tibial component on an asymptomatic patient. We came across the following complications: 1 early infection, 2 important postoperative flessum deformity having needed an arthrolysis, 1 supracondylar fracture of the femur and 1 fracture of the patellar component. Survival rate at 6-year follow-up is 97% taking into account one case of revision.

Conclusion: Non-cementation of this implant in chronic inflammatory rheumatism does not result in a higher rate of loosening. In this series, patients own satisfaction, function of the knee and survival rate are rather good.

Level of evidence: Retrospective, no control group, Level IV.