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[Comparison of total knee arthroplasty with computer navigation systems and conventional techniques].

OBJECTIVE
To evaluate the value of total knee arthroplasty (TKA) with computer navigation by comparing with conventional TKA.


METHODS
Between May 2010 and December 2011, 45 patients underwent primary unilateral TKA, and the clinical data were retrospectively analyzed. Of 45 patients, 22 cases were treated with TKA with computer navigation (group A), 23 cases with the conventional TKA (group B). There was no significant difference in gender, age, body mass index, side, cause of disease, disease duration, preoperative range of motion (ROM) of the knee, and preoperative Hospital for Special Surgery (HSS) score between 2 groups (P > 0.05). The operation time, intraoperative blood loss, incidence of patellar retinacular release, complication, and drainage volume were compared. The prosthesis loosening, postoperative HSS score, and ROM of the knee were also compared.


RESULTS
No difference was found in the incidence of patellar retinacular release during TKA, and it was 13.6% (3/22) in group A and was 4.3% (1/23) in group B, showing no significant difference (χ2 = 1.198, P = 0.346). The operation time of group A was significantly longer than that of group B (t = 7.557, P = 0.000). There was no significant difference in intraoperative blood loss during TKA between 2 groups (t = -0.295, P = 0.769), while the drainage volume of group A was significantly less than that of group B (t = -2.419, P = 0.020). Incomplete fracture during TKA and acute infection occurred at 8 days after TKA in 1 case of group A respectively, while no fracture or infection was found in group B, showing significant difference (Z = -0.509, P = 0.000). The patients of 2 groups were followed up 27-46 months. No significant difference in valgus and varus of knee, and malalignment of the femoral and tibial prosthesis was found (P > 0.05). There was no significant difference in HSS score and ROM of the knee at last follow-up between 2 groups (P > 0.05). No prosthesis loosening was found in 2 groups.


CONCLUSION
TKA with computer navigation has similar results to conventional TKA in the mechanical alignment, but it obviously prolongs operation time. It may also increase the incidence of infection and tractor pin related fracture.