Keywords:
Musculoskeletal joint, Extremities, Musculoskeletal system, Plain radiographic studies, CT, Normal variants, Complications, Prostheses, Outcomes
Authors:
V. Augustinavicius, E. Mockiene, J. Anuzis, A. Brazaitis, G. Kvederas; Vilnius/LT
DOI:
10.26044/essr2019/P-0158
Background
The knee joint is a complex structure allowing movement in three-dimensions.
There are several bony landmarks that are significant for the proper placement of prosthesis components intraoperatively.
The most often used technique for total knee arthroplasty is the mechanical alignment: cutting articular surface perpendicular to the mechanical axis.
Misalignment in any plane can lead to biomechanical changes: ligamentous imbalance,
patellar maltracking,
dysfunction of quadriceps muscle,
prosthesis failure.
Right after the knee prosthesis operation,
the first X-ray is performed to evaluate the initial prosthesis position.
Later,
for better evaluation,
a weight-bearing joint and whole-leg X-rays are performed.
In whole-leg X-ray,
the main measurements are mechanical and anatomical leg axis,
proximal medial tibial and distal lateral femoral angles,
femur and tibia valgus/varus,
whereas in joint X-ray the main measurements are joint line high and tibial slope.
CT brings radiologist an advantage to evaluate components individually and enables to measure the rotation of components.
We illustrate the main radiological techniques to obtain these measurements,
discuss common pitfalls and their impact on clinical management.