Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventi...Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA.Methods：We conducted a retrospective analysis of 212 primary TKAs in 188 patients.Intramedullary （IM）-guided resection was applied on the femoral side while extramedullary （EM）-guided resection was used on the tibial side.Using full-length X-ray,the preoperative femoral valgus angle and lower extremity alignment,as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment,were measured.Results：Postoperatively,good prosthetic alignment was achieved in 191 cases （90.1%） on the tibial side and in 144 cases （67.9%） on the femoral side （χ^2 =5.441,P =0.02）.Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane.Data were divided into five subgroups based on the valgus or varus status of the prostheses.The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414,respectively;in varus on both sides were 0.658 and 0.377,respectively;in valgus,0.555 and 0.030;femoral side varus and tibial side valgus,0.702 and 0.211;femoral side valgus and tibial side varus,-0.416 and 0.287.The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment,except for the tibial prosthetic alignment when femoral prosthesis was in valgus （P =0.153）.Conclusions：In conventional TKA,tibial side EM-guided resection may offer satisfactory postoperative alignment,and femoral resection relying on IM guide may lead to more undesirable results.Postoperative coronal alignment is mainly affected by the femoral resection.Therefore,femoral side operation should receive adequate attention from the surgeons.展开更多
Background： Identification of the proper femoral intramedullary （IM） access point is an important determinant of final implant position in IM-guided total knee arthroplasty （TKA）. The aim of this study was to ide...Background： Identification of the proper femoral intramedullary （IM） access point is an important determinant of final implant position in IM-guided total knee arthroplasty （TKA）. The aim of this study was to identify the optimal entry point in Chinese participants using a new three-dimensional method. Methods： A series of computed tomography scans of 44 femurs in Chinese participants from October 2014 to October 2015 were imported into Mimics 17.0 software to identify the optimal entry point. The apex of the intercondylar notch （AIN） was used as the reference bony anatomical landmark to identify the proper entry point to insert the IM rod. The statistical significance was calculated on the basis of a 5% level （P 〈 0.05） using the Student＇s t-test. Results： For the males, the average ideal entry point was 1.49 mm medial and 13.39 mm anterior to the AIN. The values were 1.77 mm medial and 15.29 mm anterior to the AIN in females. A significant difference was present between males and females （13.39 ±2.46 mm vs. 15.29 ± 3.44 mm, t = 2.124, P = 0.040）. When using the recommended location as the entry point for the IM rod, the mean potential error differed significantly from the femoral trochlear groove （the potential error of IM in males in coronal plane： 0.93~ ±0.24~ vs. 1.27~ ± 0.32~, t = -4.166, P 〈 0.001; the potential error of 1M in males in sagittal plane： 1.40° ± 0.42° vs. 2.79° ± 0.70°, t = -7.155, P 〈 0.001; the potential error oflM in females in coronal plane： 0.73° ± 0.28° vs. 1.15° ± 0.35°, t = -3.940, P 〈 0.001 ： and the potential error of 1M in females in sagittal plane： 1.48° ±0.47° vs. 2.76° ± 0.83°, t = -5.574, P 〈 0.001 ）. A significant difference was present between the recommended point and the point 10 mm anterior to the origin of the posterior cruciate ligament （the potential error of IM in males in coronal plane： 0.93° ± 0.24° vs. 1.53° ±0.43°, t = -5.948, P 〈 0.001 ; the potential error of IM in males in sagittal plane： 1.40° ± 0.42° vs. 2.15°± 0.75°, t = -3.152, P = 0.003; the potential error of IM in females in coronal plane： 0.73° ± 0.28° vs. 1.28° ±0.42°, t = -4.632, P 〈 0.001; and the potential error oflM in females in sagittal plane： 1.48°± 0.47° vs. 2.40°± 0.93°, t = -3.763, P = 0.001）. Conclusions： The technique described here is an innovative method for swift, easy, and accurate access to the medullary canal during TKA, and it can optimize the position and orientation of the prosthetic components in knee arthroplasty.展开更多
文摘Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA.Methods：We conducted a retrospective analysis of 212 primary TKAs in 188 patients.Intramedullary （IM）-guided resection was applied on the femoral side while extramedullary （EM）-guided resection was used on the tibial side.Using full-length X-ray,the preoperative femoral valgus angle and lower extremity alignment,as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment,were measured.Results：Postoperatively,good prosthetic alignment was achieved in 191 cases （90.1%） on the tibial side and in 144 cases （67.9%） on the femoral side （χ^2 =5.441,P =0.02）.Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane.Data were divided into five subgroups based on the valgus or varus status of the prostheses.The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414,respectively;in varus on both sides were 0.658 and 0.377,respectively;in valgus,0.555 and 0.030;femoral side varus and tibial side valgus,0.702 and 0.211;femoral side valgus and tibial side varus,-0.416 and 0.287.The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment,except for the tibial prosthetic alignment when femoral prosthesis was in valgus （P =0.153）.Conclusions：In conventional TKA,tibial side EM-guided resection may offer satisfactory postoperative alignment,and femoral resection relying on IM guide may lead to more undesirable results.Postoperative coronal alignment is mainly affected by the femoral resection.Therefore,femoral side operation should receive adequate attention from the surgeons.
文摘Background： Identification of the proper femoral intramedullary （IM） access point is an important determinant of final implant position in IM-guided total knee arthroplasty （TKA）. The aim of this study was to identify the optimal entry point in Chinese participants using a new three-dimensional method. Methods： A series of computed tomography scans of 44 femurs in Chinese participants from October 2014 to October 2015 were imported into Mimics 17.0 software to identify the optimal entry point. The apex of the intercondylar notch （AIN） was used as the reference bony anatomical landmark to identify the proper entry point to insert the IM rod. The statistical significance was calculated on the basis of a 5% level （P 〈 0.05） using the Student＇s t-test. Results： For the males, the average ideal entry point was 1.49 mm medial and 13.39 mm anterior to the AIN. The values were 1.77 mm medial and 15.29 mm anterior to the AIN in females. A significant difference was present between males and females （13.39 ±2.46 mm vs. 15.29 ± 3.44 mm, t = 2.124, P = 0.040）. When using the recommended location as the entry point for the IM rod, the mean potential error differed significantly from the femoral trochlear groove （the potential error of IM in males in coronal plane： 0.93~ ±0.24~ vs. 1.27~ ± 0.32~, t = -4.166, P 〈 0.001; the potential error of 1M in males in sagittal plane： 1.40° ± 0.42° vs. 2.79° ± 0.70°, t = -7.155, P 〈 0.001; the potential error oflM in females in coronal plane： 0.73° ± 0.28° vs. 1.15° ± 0.35°, t = -3.940, P 〈 0.001 ： and the potential error of 1M in females in sagittal plane： 1.48° ±0.47° vs. 2.76° ± 0.83°, t = -5.574, P 〈 0.001 ）. A significant difference was present between the recommended point and the point 10 mm anterior to the origin of the posterior cruciate ligament （the potential error of IM in males in coronal plane： 0.93° ± 0.24° vs. 1.53° ±0.43°, t = -5.948, P 〈 0.001 ; the potential error of IM in males in sagittal plane： 1.40° ± 0.42° vs. 2.15°± 0.75°, t = -3.152, P = 0.003; the potential error of IM in females in coronal plane： 0.73° ± 0.28° vs. 1.28° ±0.42°, t = -4.632, P 〈 0.001; and the potential error oflM in females in sagittal plane： 1.48°± 0.47° vs. 2.40°± 0.93°, t = -3.763, P = 0.001）. Conclusions： The technique described here is an innovative method for swift, easy, and accurate access to the medullary canal during TKA, and it can optimize the position and orientation of the prosthetic components in knee arthroplasty.
