About This File
This model is the right knee muscle rendering of a 65-year-old male with left thigh myxoid fibrosarcoma. At the time of diagnosis, the patient had metastases to his lungs. The patient therefore underwent neoadjuvant radiotherapy, surgery, and adjuvant chemotherapy and was found to have an intermediate grade lesion at the time of diagnosis. The patient is still living with the metastatic disease at 2.5 years since diagnosis. This is an STL file created from DICOM images of his CT scan which may be used for 3D printing.
The knee is a hinge joint that does not have true bony stabilization, so it requires soft tissue static and dynamic stabilizers to prevent excess motion through the joint. In addition, the knee goes through a “screw home” mechanism in which the tibia rotates externally and “locks” into extension during the last 15-20 degrees of extension. Multiple structures, therefore, are needed to work in concert to prevent excess strain through this joint during these daily motions.
On the medial aspect of the knee, the static stabilizers consist of the superficial and deep medial collateral ligaments (MCL) and the posterior oblique ligament (POL). The dynamic stabilizers are the semimembranosus, vastus medialis, medial gastrocnemius, and pes tendons (semitendinosus, gracilis, and sartorius). The lateral stabilizers are best known as the posterolateral corner, and consist of the static stabilizers (lateral collateral ligament (LCL), iliotibial band (ITB), arcuate ligament), and dynamic stabilizers (popliteus, biceps femoris, lateral gastrocnemius). Inside the joint, the anterior cruciate ligament provides resistance to anterior tibial translation varus, and internal rotation, whereas the posterior cruciate ligament provides resistance to posterior tibial translation, varus, valgus, and external rotation.
This model was created from the file STS_022.