Conventional versus computer-navigated TKA: a prospective randomized study.
OBJECTIVE
The purpose of this study was to assess the midterm results of total knee arthroplasty (TKA) implanted with a specific computer navigation system in a group of patients (NAV) and to assess the same prosthesis implanted with the conventional technique in another group (CON); we hypothesized that computer navigation surgery would improve implant alignment, functional scores and survival of the implant compared to the conventional technique.


METHODS
From 2008 to 2009, 225 patients were enrolled in the study and randomly assigned in CON and NAV groups; 240 consecutive mobile-bearing ultra-congruent score (Amplitude, Valence, France) TKAs were performed by a single surgeon, 117 using the conventional method and 123 using the computer-navigated approach. Clinical outcome assessment was based on the Knee Society Score (KSS), the Hospital for Special Surgery Knee Score and the Western Ontario Mac Master University Index score. Component survival was calculated by Kaplan-Meier analysis.


RESULTS
Median follow-up was 6.4 years (range 6-7 years). Two patients were lost to follow-up. No differences were seen between the two groups in age, sex, BMI and side of implantation. Three patients of CON group referred feelings of instability during walking, but clinical tests were all negative. NAV group showed statistical significant better KSS Score and wider ROM and fewer outliers from neutral mechanical axis, lateral distal femoral angle, medial proximal tibial angle and tibial slope in post-operative radiographic assessment. There was one case of early post-operative superficial infection (caused by Staph. Aureus) successfully treated with antibiotics. No mechanical loosening, mobile-bearing dislocation or patellofemoral complication was seen. At 7 years of follow-up, component survival in relation to the risk of aseptic loosening or other complications was 100 %. There were no implant revisions.


CONCLUSIONS
This study demonstrates superior accuracy in implant positioning and statistical significant better functional outcomes of computer-navigated TKA. Computer navigation for TKAs should be used routinely in primary implants.


METHODS
II.
Department of Orthopaedic Surgery, Istituto Chirurgico Ortopedico Traumatologico (ICOT), Latina, Italy.
Alessandro
A
Todesca
Department of Orthopaedics and Traumatology, University of Rome Tor Vergata, Rome, Italy. garro.luca@gmail.com.
Luca
L
Garro
Department of Orthopaedic Surgery, Istituto Chirurgico Ortopedico Traumatologico (ICOT), Latina, Italy.
Massimo
M
Penna
Department of Orthopaedic Surgery, Istituto Chirurgico Ortopedico Traumatologico (ICOT), Latina, Italy.
Jacques
J
Bejui-Hugues
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005269:Femur / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D011183:Postoperative Complications / Q000188:drug therapy; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013977:Tibia / Q000601:surgery
Computer navigation; Computer-assisted surgery; Implant alignment; Implant survival; Knee prosthesis; Knee replacement; Knee surgery; Mechanical axis; Soft-tissue balancing; Total knee arthroplasty