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Ryuji Nagamine - One of the best experts on this subject based on the ideXlab platform.
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coronal alignment of the varus knees with medial shift of the Tibial articular surface
Orthopaedic Proceedings, 2018Co-Authors: Ryuji Nagamine, Chen Weijia, Mitsugu Todo, Kaoru Osano, M Takayama, M Kawasaki, Ryutaku KaneyamaAbstract:IntroductionThe hip-knee-ankle (HKA) angle between the mechanical axis of the femur (FM) and the mechanical axis of the Tibia (TM) is the standard parameter to assess the coronal alignment of the lower extremity. TM is the line between the center of the Tibial spines notch (Point T) and the center of the Tibial plafond. However, this theory is based on the premise that TM coincides the anatomical axis of the Tibia (TA). Fig.1a shows typical varus knee with medial shift of the Tibial articular surface. In this case, TM does not coincide TA. Fig. 2 demonstrates the error of HKA angle when Point T locates medial to TA. Fig.2a shows normal alignment. Fig.2b shows varus alignment. Fig. 2c shows the Tibia with medial shift of the Tibial articular surface. The Tibia has 7 degrees varus articular inclination in Fig.2b and 2c. However, HKA angle is 0 degree in Fig.2c. HKA angle underestimates varus deformity in knees with medial shift of the Tibial articular surface. However, the degree of medial shift of the tibi...
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ab0814 medial shift of the Tibial articular surface should be taken into account for one factor of medial osteoarthritis of the knee
Annals of the Rheumatic Diseases, 2017Co-Authors: Ryuji NagamineAbstract:Background Varus knee is one factor of medial osteoarthritis of the knee. According to the concept of the constitutional varus1), the bone growth disturbance at the growth plate in the medial proximal metaphysis of the Tibia results in proximal Tibia vara. In this situation, the Tibia is bent at the proximal metaphysis and the Tibial articular surface (TAS) may be shift medially. The medial shift of the TAS will increase the mechanical loading in the medial side of the knee. The medial shift of TAS will also influence the value of the Hip-knee-ankle (HKA) angle because the Tibial plafond that is the end point of the mechanical axis (MA) of the Tibia will shift laterally. Objectives The purpose of this study was to assess the extent of the medial shift of TAS in knees with medial osteoarthritis, and to assess the effect of this medial shift of TAS on the value of HKA angle. Methods This study consists of 116 knees with medial osteoarthritis. The mean age was 75.3 years old. The mean standing femoroTibial angle (FTA: lateral angle between femoral and Tibial anatomical axes) was 183.6°. The anatomical axis (AA) was the central line of the femoral and the Tibial shaft. On the anteroposterior view radiograph of the Tibia, AA, MA and Tibial plateau tangent were drawn. MA is the line between the center of the Tibial spines notch and the center of the Tibial plafond. Two angle parameters and two distance parameters were measured. Those are angle between AA and MA (Angle AA-MA) (the value was positive when MA located medial to AA), angle between the Tibial plateau tangent and the line perpendicular to AA (Angle plateau), distance from AA to the center of the Tibial spines notch on the Tibial plateau (Distance AA-MA) (the value was positive when Point M located medial to AA), and the length of MA. Results The mean (±SD) Angle AA-MA and Angle plateau was 1.0° ± 0.6° and 8.2° ± 2.9°, respectively. The mean Distance AA-MA and length of MA was 5.6±3.4mm and 347.3±3.4mm, respectively. Figure 1 shows the relationship between Angle Plateau and Distance AA-MA. The correlation coefficient between two parameters was 0.62. The more proximal Tibia had varus deformity, the more the Tibial articular surface shifted medially. The maximum Distance AA-MA was 16.1mm. In this case, HKA angle underestimated varus deformity up to 3°. Conclusions The knees with proximal Tibia vara have medial shift of the Tibial articular surface. There are three factors to influence the evaluations of the medial osteoarthritis of the knees. Firstly, varus knees have higher loading condition in medial compartment because of proximal Tibia vara and medial shift of the Tibial articular surface. Secondly, HKA angle under-estimates varus deformity in knees with medial shift of the Tibial articular surface. Thirdly, FTA cannot reveal the exact loading condition, either. Even with the same FTA, it is clear that loading in the medial compartment is larger in knees with medial shift of the Tibial articular surface compared with knees with simple medial osteoarthritis. The medial shift of the Tibial articular surface should be taken into account for one factor of medial osteoarthritis of the knee. References Bellemans J, et al. The Chitranjan Ranawat award: is neutral mechanical alignment normal for all patients? The concept of constitutional varus. Clin Orthop Relat Res. 2012;470(1):45–53. Acknowledgements none. Disclosure of Interest None declared
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coronal alignment of the varus knees with medial shift of the Tibial articular surface
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Ryuji Nagamine, Chen Weijia, Mitsugu Todo, Kaoru Osano, M Takayama, M Kawasaki, Ryutaku KaneyamaAbstract:Introduction The hip-knee-ankle (HKA) angle between the mechanical axis of the femur (FM) and the mechanical axis of the Tibia (TM) is the standard parameter to assess the coronal alignment of the lower extremity. TM is the line between the center of the Tibial spines notch (Point T) and the center of the Tibial plafond. However, this theory is based on the premise that TM coincides the anatomical axis of the Tibia (TA). Fig.1a shows typical varus knee with medial shift of the Tibial articular surface. In this case, TM does not coincide TA. Fig. 2 demonstrates the error of HKA angle when Point T locates medial to TA. Fig.2a shows normal alignment. Fig.2b shows varus alignment. Fig. 2c shows the Tibia with medial shift of the Tibial articular surface. The Tibia has 7 degrees varus articular inclination in Fig.2b and 2c. However, HKA angle is 0 degree in Fig.2c. HKA angle underestimates varus deformity in knees with medial shift of the Tibial articular surface. However, the degree of medial shift of the Tibial articular surface is obscure. In this study, detailed anatomical configuration of the proximal Tibia was evaluated. The effect of the value of HKA angle on the coronal alignment in TKA was then discussed. Methods This study consists of 117 knees. On the AP view radiograph of the Tibia, three distance and two angle parameters were measured. Those were Tibial articular surface width, distance between medial edge of the Tibial articular surface and Point T, distance from TA to Point T. Angle between TM and TA, and the varus inclination angle of the Tibial articular surface relative to the perpendicular line to TA. Results The mean width of the Tibial articular surface was 87.8mm. The mean distance between Point T and medial edge of the articular surface was 43.6mm. Point T located at the center of the Tibial articular surface. The mean distance from TA to Point T was 5.6mm. The mean angle between TM and TA was 1.0 degrees. The inclination angle of the Tibial articular surface was 8.2 degrees. Discussion The results clearly showed that varus knees had medial shift of the Tibial articular surface. In such knees, the ankle shifts laterally relative to the Point T and HKA angle underestimates the varus deformity. The value of HKA angle also influences the evaluation of the coronal alignment of the lower extremity in TKA (Fig. 3). When the Tibial tray is set based on the Tibial articular surface width in order to cover the cut surface of the Tibia, HKA angle shows the alignment as valgus when the Tibial tray is set perpendicular to TA (Fig. 3a). In order to obtain zero degree of HKA angle, the Tibial tray should be set perpendicular to TM. This alignment is varus (Fig. 3b). Reduction osteotomy is one procedure to match the value of HKA angle and the true alignment (Fig. 3c). In this technique, HKA angle is zero degree, and TM and TA coincide. For figures, please contact authors directly.
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Alignment in total knee arthroplasty following failed high Tibial osteotomy.
Journal of Knee Surgery, 2003Co-Authors: Tsutomu Kawano, Ken Urabe, Ryuji Nagamine, Taro Mawatari, Taka Aki Moro-oka, Shuichi Matsuda, Hiromasa Miura, Yukihide IwamotoAbstract:: In total knee arthroplasty (TKA) following failed high Tibial osteotomy, the mechanical axis does not intersect the center of the Tibial component if the Tibia has been resected perpendicular to the anatomical axis. Therefore, Tibial resection referencing the predicted postoperative mechanical axis instead of the Tibial shaft axis is advocated. To obtain the optimal Tibial resection, characteristics of the Tibial proximal deformity were measured radiographically and predicted postoperative lower limb alignment was calculated using full-length, weight-bearing, lower limb anteroposterior radiographs. Two finite element analysis models also were examined. The proximal Tibia was resected perpendicular to the Tibial shaft axis in model 1, and perpendicular to the predicted postoperative Tibial mechanical axis in model 2. When the proximal Tibia was resected perpendicular to the Tibial shaft axis, the predicted lower limb mechanical axis was significantly shifted medially to the center of the Tibial joint surface. The results of the finite element analysis reflected the medial shift of the lower limb mechanical axis in model 1, where stresses were increased in the medial Tibial compartment. Tibial resection referencing the predicted postoperative Tibial mechanical axis, instead of the Tibial shaft axis, should be performed, especially in cases with a deformed Tibia.
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Tibial shaft axis does not always serve as a correct coronal landmark in total knee arthroplasty for varus knees
Journal of Arthroplasty, 2003Co-Authors: Shuichi Matsuda, Ken Urabe, Hideki Mizuuchi, Ryuji Nagamine, Hiromasa Miura, Yukihide IwamotoAbstract:Predicted postoperative knee alignment was calculated when total knee arthroplasty was performed after 1 of 3 different methods of Tibia preparation in 30 osteoarthritic knees with varus deformity. In Method 1, the Tibia was cut perpendicular to the Tibial shaft. In Method 2, the Tibia was cut perpendicular to a line connecting the center of the Tibial plateau and the center of the talar dome. In method 3, Tibial resection was determined with an original template so that Tibial resection would be perpendicular to a line connecting the center of the resected Tibial plateau and the center of the talar dome. Methods 1 and 2 caused significantly more valgus alignment than Method 3 (P<.0001). The postoperative weight-bearing ratio was in Method 1, 57.7%, in Method 2, 53.6% and 50.0% in Method 3. These results suggest that cutting the Tibia perpendicular to the Tibial shaft can cause valgus alignment in total knee arthroplasty for varus knees. Copyright 2003, Elsevier Science (USA). All rights reserved.
Ryutaku Kaneyama - One of the best experts on this subject based on the ideXlab platform.
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coronal alignment of the varus knees with medial shift of the Tibial articular surface
Orthopaedic Proceedings, 2018Co-Authors: Ryuji Nagamine, Chen Weijia, Mitsugu Todo, Kaoru Osano, M Takayama, M Kawasaki, Ryutaku KaneyamaAbstract:IntroductionThe hip-knee-ankle (HKA) angle between the mechanical axis of the femur (FM) and the mechanical axis of the Tibia (TM) is the standard parameter to assess the coronal alignment of the lower extremity. TM is the line between the center of the Tibial spines notch (Point T) and the center of the Tibial plafond. However, this theory is based on the premise that TM coincides the anatomical axis of the Tibia (TA). Fig.1a shows typical varus knee with medial shift of the Tibial articular surface. In this case, TM does not coincide TA. Fig. 2 demonstrates the error of HKA angle when Point T locates medial to TA. Fig.2a shows normal alignment. Fig.2b shows varus alignment. Fig. 2c shows the Tibia with medial shift of the Tibial articular surface. The Tibia has 7 degrees varus articular inclination in Fig.2b and 2c. However, HKA angle is 0 degree in Fig.2c. HKA angle underestimates varus deformity in knees with medial shift of the Tibial articular surface. However, the degree of medial shift of the tibi...
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coronal alignment of the varus knees with medial shift of the Tibial articular surface
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Ryuji Nagamine, Chen Weijia, Mitsugu Todo, Kaoru Osano, M Takayama, M Kawasaki, Ryutaku KaneyamaAbstract:Introduction The hip-knee-ankle (HKA) angle between the mechanical axis of the femur (FM) and the mechanical axis of the Tibia (TM) is the standard parameter to assess the coronal alignment of the lower extremity. TM is the line between the center of the Tibial spines notch (Point T) and the center of the Tibial plafond. However, this theory is based on the premise that TM coincides the anatomical axis of the Tibia (TA). Fig.1a shows typical varus knee with medial shift of the Tibial articular surface. In this case, TM does not coincide TA. Fig. 2 demonstrates the error of HKA angle when Point T locates medial to TA. Fig.2a shows normal alignment. Fig.2b shows varus alignment. Fig. 2c shows the Tibia with medial shift of the Tibial articular surface. The Tibia has 7 degrees varus articular inclination in Fig.2b and 2c. However, HKA angle is 0 degree in Fig.2c. HKA angle underestimates varus deformity in knees with medial shift of the Tibial articular surface. However, the degree of medial shift of the Tibial articular surface is obscure. In this study, detailed anatomical configuration of the proximal Tibia was evaluated. The effect of the value of HKA angle on the coronal alignment in TKA was then discussed. Methods This study consists of 117 knees. On the AP view radiograph of the Tibia, three distance and two angle parameters were measured. Those were Tibial articular surface width, distance between medial edge of the Tibial articular surface and Point T, distance from TA to Point T. Angle between TM and TA, and the varus inclination angle of the Tibial articular surface relative to the perpendicular line to TA. Results The mean width of the Tibial articular surface was 87.8mm. The mean distance between Point T and medial edge of the articular surface was 43.6mm. Point T located at the center of the Tibial articular surface. The mean distance from TA to Point T was 5.6mm. The mean angle between TM and TA was 1.0 degrees. The inclination angle of the Tibial articular surface was 8.2 degrees. Discussion The results clearly showed that varus knees had medial shift of the Tibial articular surface. In such knees, the ankle shifts laterally relative to the Point T and HKA angle underestimates the varus deformity. The value of HKA angle also influences the evaluation of the coronal alignment of the lower extremity in TKA (Fig. 3). When the Tibial tray is set based on the Tibial articular surface width in order to cover the cut surface of the Tibia, HKA angle shows the alignment as valgus when the Tibial tray is set perpendicular to TA (Fig. 3a). In order to obtain zero degree of HKA angle, the Tibial tray should be set perpendicular to TM. This alignment is varus (Fig. 3b). Reduction osteotomy is one procedure to match the value of HKA angle and the true alignment (Fig. 3c). In this technique, HKA angle is zero degree, and TM and TA coincide. For figures, please contact authors directly.
Yukihide Iwamoto - One of the best experts on this subject based on the ideXlab platform.
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Alignment in total knee arthroplasty following failed high Tibial osteotomy.
Journal of Knee Surgery, 2003Co-Authors: Tsutomu Kawano, Ken Urabe, Ryuji Nagamine, Taro Mawatari, Taka Aki Moro-oka, Shuichi Matsuda, Hiromasa Miura, Yukihide IwamotoAbstract:: In total knee arthroplasty (TKA) following failed high Tibial osteotomy, the mechanical axis does not intersect the center of the Tibial component if the Tibia has been resected perpendicular to the anatomical axis. Therefore, Tibial resection referencing the predicted postoperative mechanical axis instead of the Tibial shaft axis is advocated. To obtain the optimal Tibial resection, characteristics of the Tibial proximal deformity were measured radiographically and predicted postoperative lower limb alignment was calculated using full-length, weight-bearing, lower limb anteroposterior radiographs. Two finite element analysis models also were examined. The proximal Tibia was resected perpendicular to the Tibial shaft axis in model 1, and perpendicular to the predicted postoperative Tibial mechanical axis in model 2. When the proximal Tibia was resected perpendicular to the Tibial shaft axis, the predicted lower limb mechanical axis was significantly shifted medially to the center of the Tibial joint surface. The results of the finite element analysis reflected the medial shift of the lower limb mechanical axis in model 1, where stresses were increased in the medial Tibial compartment. Tibial resection referencing the predicted postoperative Tibial mechanical axis, instead of the Tibial shaft axis, should be performed, especially in cases with a deformed Tibia.
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Tibial shaft axis does not always serve as a correct coronal landmark in total knee arthroplasty for varus knees
Journal of Arthroplasty, 2003Co-Authors: Shuichi Matsuda, Ken Urabe, Hideki Mizuuchi, Ryuji Nagamine, Hiromasa Miura, Yukihide IwamotoAbstract:Predicted postoperative knee alignment was calculated when total knee arthroplasty was performed after 1 of 3 different methods of Tibia preparation in 30 osteoarthritic knees with varus deformity. In Method 1, the Tibia was cut perpendicular to the Tibial shaft. In Method 2, the Tibia was cut perpendicular to a line connecting the center of the Tibial plateau and the center of the talar dome. In method 3, Tibial resection was determined with an original template so that Tibial resection would be perpendicular to a line connecting the center of the resected Tibial plateau and the center of the talar dome. Methods 1 and 2 caused significantly more valgus alignment than Method 3 (P<.0001). The postoperative weight-bearing ratio was in Method 1, 57.7%, in Method 2, 53.6% and 50.0% in Method 3. These results suggest that cutting the Tibia perpendicular to the Tibial shaft can cause valgus alignment in total knee arthroplasty for varus knees. Copyright 2003, Elsevier Science (USA). All rights reserved.
Alexander Katzman - One of the best experts on this subject based on the ideXlab platform.
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The use of the Taylor spatial frame in adolescent Blount’s disease: is fibular osteotomy necessary?
Journal of Children's Orthopaedics, 2008Co-Authors: Mark Eidelman, Viktor Bialik, Alexander KatzmanAbstract:Background The standard treatment of adolescent Blount disease includes proximal Tibial osteotomy and osteotomy of the fibula. Some believe that the fibula should also be fixed to prevent migration and subluxation. The purpose of the current study was to examine the results of treatment of patients with adolescent Tibia vara treated by Tibial osteotomy and Taylor spatial frame (TSF) without fibular osteotomy. Methods Correction of deformities was performed on eight patients (ten Tibias) with adolescent Blount disease using TSF. The fibula was not osteotomized in any patient and was not fixed in the last five patients. Results All patients had precise anatomical correction of deformities and no problems related to the fibula occurred during or after correction. Conclusion Based on our experience we believe that placement of the origin at the level of the proximal Tibial fibular joint in conjunction with external fixation eliminates the need for fibular osteotomy and the potential morbidity of this procedure in patients with mild to moderate Tibia vara.
Andrej Maria Nowakowski - One of the best experts on this subject based on the ideXlab platform.
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Total knee arthroplasty: posterior Tibial slope influences the size but not the rotational alignment of the Tibial component
Knee Surgery Sports Traumatology Arthroscopy, 2020Co-Authors: Petros Ismailidis, Valerie Kremo, Annegret Mündermann, Magdalena Müller-gerbl, Andrej Maria NowakowskiAbstract:Purpose The reasons leading to rotational Tibial malalignment in total knee arthroplasties (TKAs) remain unclear. A previous cadaver study has shown an increase in internal rotation of the anatomical Tibial axis (ATA) after the Tibial cut. This study investigates the influence of Tibial slope on the ATA and the size of the resected Tibial surface. Methods CT scans of 20 cadaver knees were orientated in a standardized coordinate system and used to determine the position of the centres of rotation of the medial and lateral Tibial articular surfaces and, hence, of the ATA, after a virtual resection of 6 mm with 0°, 3.5°, 7° and 10° slope, respectively. Furthermore, at each slope, the radii of the medial and lateral Tibial articular surfaces after resection were calculated. Results Compared to resection of 6 mm with 0° slope, a slope of 3.5° resulted in a mean external rotation of the ATA of 0.9° (SD, 1.5°; P = 0.025). A slope of 7° resulted in a mean external rotation of the ATA of 1.0° (SD 2.0°; P = 0.030) and a slope of 10° had no influence on the rotation of the ATA. The radii of the medial and lateral articular surfaces of the cut Tibiae were larger than those of the uncut Tibia ( P
