A Human Knee Joing Model Based on Screw Theory and its Relevance for Preoperative Planning

Abstract

The human knee joint is subjected to a high demand when performing its biomechanical function and injuries are frequent. Rupture of the anterior cruciate ligament (ACL) is the most common injury of human knee and causes great instability to it, decreased functional ability as well as degeneration of the menisci and adjacent articular cartilage. Cartilage problems and ligament injuries are treated surgically using grafts in replacement of the ligaments, in case of ligament reconstruction, or using prosthesis, in case of osteoarthritis.
The surgical treatment for injuries involves the knee joint surgery, physiotherapy and rehabilitation procedures to restore the patient’s functional abilities of the knee. For the surgery, the orthopedic surgeon must plan the surgery in order to obtain better results postoperatively. The preoperative planning is a critical step in selecting the surgical technique and definition of parameters to be used in surgery for each patient and thus can directly affect the results of surgery.
For an appropriate preoperative planning, the orthopedic surgeon needs to know the exact problem to be solved, possible surgical solutions and the expected consequences for each solution.
This work propose a methodology for computational mechanical modeling of the knee based on the theory of mechanisms, screw theory and the Davies method, in order to assist the preoperative planning and provide to the orthopedic surgeon objective information simulated by model that assist in medical decision making.