[Clinical effects of total knee arthroplasty in the treatment of ankylosed knee].

OBJECTIVE: To investigate the clinical effects of total knee arthroplasty in treatment of ankylosed knee caused by various reasons. METHODS: Four patients with 7 ankylosed knees, caused by ankylosing spondylitis in 1 case, septic arthritis with bony ankylosis in 1 case, and rheumatoid arthritis in 2 cases, underwent artificial knee replacement. Before the operation joint activity was 0 degrees , Knee Society score (KSS) was 42 (11 - 63), and the function score was 17. Follow-up was conducted for 5 - 27 months. RESULTS: Follow-up showed that the average joint activity was raised to 83 degrees (60 degrees - 110 degrees ), KSS score to 83 (64 - 91) points, and function score to 77 points. No infectious case was found. CONCLUSION: Total knee arthroplasty has a satisfactory effect in treatment of ankylosed knee. Computer assisted navigation system is helpful in femoro-tibial osteotomy and soft tissue balance. Individualized and directed rehabilitation is a pivotal factor.

[Computer-assisted navigation for total knee arthroplasty: a comparative study with conventional methods].

OBJECTIVE: To compare the effects of Computer-assisted navigation (CAS) and conventional location technique in total knee arthroplasty (TKA). METHODS: Eight patients (11 knees) underwent CAS and 9 patients (11 knees) underwent conventional location technique for TKA. Follow-up was conducted for 5 - 12 months. The outcomes were compared. RESULTS: The mechanical axe error of the CAS group was (2.14 +/- 0.25) degrees, significantly less than that of the conventional group [(5.12 +/- 2.13) degrees, P = 0.005]. The soft tissue balance angle variable of the CAS group was (1.04 +/- 0.18) degrees, significantly less than that of the conventional group [(4.12 +/- 1.72) degrees, P = 0.005]. The soft tissue separation variable of the CAS group was (3.4 +/- 1.2) mm, significantly less than that of the conventional group [(6.1 +/- 2.4) mm, P = 0.005]. No fat embolism occurred in these 2 groups. The operating time of the CAS group was (82 +/- 18) min, significantly longer than that of the conventional group [(59 +/- 11) min, P = 0.005]. CONCLUSION: CAS causes more reliable artificial joint implantation and better soft-tissues balance, however, needs more operating time.