RESUMO
Objective To explore the advantages of computer assisted total knee arthroplasty(TKA)by comparing the post-operative 1 year short term effect of the computer assisted TKA and the conventional TKA .Methods A total of 60 patients from September 2013 to September 2014 were randomly divided into two groups and performed TKA by adopting the computer-assisted technology and the conventional technology respectively .The KSS score ,WOMAC score ,Oxford score and long-leg weight-bearing X-ray before operation and at postoperative 1 year were performed for each case and the statistical analysis was conducted . Results All cases were followed up for an average of 12 months (12—14 months) .The mechanical limb axis in the navigation as-sisted group was —0 .033o± 1 .470o ,which in the traditional group was 0 .600o± 2 .989o(t= —1 .711 ,P<0 .05);the proportions of within 3o varus/valgus force lines were 86 .70% and 73 .30% respectively ,the KSS scores were 88 .80 ± 3 .71 and 82 .63 ± 4 .15;the postoperative WOMAC scores were 23 .57 ± 3 .64 and 30 .00 ± 4 .89 respectively ;the Oxford scores were 18 .53 ± 3 .66 and 21 .83 ± 3 .99 ,the differences between the two groups were statistically significant (P<0 .005) .Conclusion TKA by computer navigation guidance can obtain more accurate lower limb force lines ,moreover the navigation group has more advantages in the clinical rehabili-tation effect .
RESUMO
PURPOSE: We analyzed the patterns and causative factors of early aseptic loosening after total knee arthroplasty (TKR) using a legacy posterior stabilized (LPS)-flex prosthesis. MATERIALS AND METHODS: We examined 483 cases that occurred in 311 patients who underwent TKR using LPS-flex by single surgeon between August 2001 and March 2007 and who were followed-up for at least 2 years. The loosened group included 25 cases that exhibited early aseptic loosening on radiograph, the remaining 458 cases were regarded as the control group, and analysis was performed. RESULTS: The mean loosening period was 34.7 months and femoral component loosening alone was found in 22 cases (88%). There were no statistically significant differences in age, body mass index, or pre-operative range of motion between the 2 groups, but varus deformity was more severe in the loosened group (mean 8.92degrees) than in the control group (mean 5.21degrees) (p=0.003). Protrusion of the femoral component proximally over posterior condyle of the distal femur were more prominent in the loosened group (mean 20.3%) than in the control group (mean 13.4%) (p=0.001). CONCLUSION: Early loosening after TKR using LPS-flex prosthesis developed mostly in the femoral component. Choosing a proper size for the femoral component and cutting level for the distal femur should be considered.