Total­ knee ­arthroplasty­ in ­young­ patients­ with­ rheumatoid arthritis

Abstract

Background:­ The main purpose of this study was to evaluate the outcomes of total knee arthroplasty in patients <55 years with rheumatoid arthritis analyzing the distinctive features of this group (range of motion, pain, prosthesis survival).Methods: Twenty four total knee arthroplasties in 14 patients (12 women) were evaluated. Average age: 47.4 years, with a follow-up of 5.8 years. Four were unilateral replacements and ten were bilateral. Twenty foreign design implants and 4 national ones were used. One patient (4.16%) required a metallic wedge and two (8.3%) needed femoral and tibial stems.Results: Before surgery 14 knees presented extension deficit and average range of motion was of 92.8°. The preoperative femorotibial angle was valgus in 22 knees with an average of 12° and 2 varus with average of 3°. Postoperative range of motion at 6 weeks was an average of 90º and 110º at first years, in all patients. Knee Society clinical and functional score improved from an average of 42 to 83, and from 42 to 89, respectively. There were 2 complications: an extensor mechanism rupture that was resutured, developing a synovial fistula that required 3 toilettes, with favorable outcome and one mechanical loosening that required revision.Conclusions:­ At the expense of pain relief and functional improvement, total knee arthroplasty in young patients with rheumatoid arthritis seems a procedure with very good medium term outcomes. Preoperative planning, taking into account the possibility of using stem and metal supplements, is necessary.