Innervation of the distal part of the vastus medialis muscle is endangered by splitting its muscle fibers during total knee replacement: an anatomical study using modified Sihler’s technique

The aim of this study has been to develop a dynamic model of the knee joint after total knee replacement (TKR) to analyse the stress distribution in the distal femur during daily activities. Using MSC/ADAMS and MSC/MARC software, a dynamic model of an implanted knee joint has been developed. This model consists of the components of the knee prosthesis as well as the bones and ligaments of the knee. The femur, tibia, fibula, and patella have been modelled as mixed cortico-cancellous bone. The distal part of femur has been modelled as a flexible body with springs used to simulate the ligaments positioned at their anatomical insertion points. With this dynamic model a gait cycle was simulated. Stress shielding was identified in the distal femur after TKR, which is consistent with other investigators' results. Interestingly, higher stresses were found in the bone adjacent to the femoral component peg. This dynamic model can now be used to analyse the stress distribution in the distal femur with different load conditions. This will help to improve implant designs and will allow comparison of prostheses from different manufacturers.

Download Full-text

Anatomical Study of Femoral Condylar Index in Magnetic Resonance Imaging: Implication to Total Knee Replacement Surgery for Vietnamese People

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2019.836 ◽

2019 ◽

Vol 7 (24) ◽

pp. 4362-4367

Author(s):

Dung Tran Trung ◽

Phuong Nguyen Huy ◽

Tung Pham Son ◽

Thien Chu Dinh ◽

Toi Chu Dinh

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Total Knee Replacement ◽

Knee Replacement ◽

Rotation Angle ◽

Anatomical Study ◽

Femoral Rotation ◽

Resonance Imaging ◽

Transepicondylar Axis ◽

Total Knee

BACKGROUND: The femoral rotation angle is important element in total knee replacement (TKR). AIM: To measure this angle, we determine through the axes: the transepicondylar axis (cTEA and sTEA), the posterior condylar axis (PCA), the anteroposterior axis (APA – Whiteside axis). METHODS: Measuring the angles created by the four axes: cTEA, sTEA, PCA and APA in magnetic resonance imaging (MRI); determining the femoral rotation angle and application TKR. RESULTS: the angle between APA and cTEA: 90.41° ± 3.35°, the angle between APA and sTEA: 94.47° ± 3.31°, the angle between APA and PCA: 96.40° ± 4.59°, the angle between cTEA and sTEA: 4.00° ± 1.02°, the angle between cTEA and PCA: 6.53° ± 2.55°, the angle between sTEA and PCA: 3.48° ± 1.91°. CONCLUSION: The angle between sTEA and PCA is the angle that best represents the femoral rotation angle. However, in case of sTEA or PCA is difficult to identify, it can be measure via the APA or cTEA. These angles don’t differ by age, gender and place of knee joint.

Download Full-text