By simply adding a flexion plate to his existing alignment (purple arrow) the patient can now stand on his prosthesis with greater stability and confidence.
Although this is a dramatic depiction of a transfemoral patient with a significant hip flexion contracture, it is something many above knee amputees and their prosthetist deal with to various degrees. A Thomas test would show that this patient has a contracture of approximately 35 to 40 degrees.
The picture on the left shows the weight line or TKA line, bisecting the socket with the center of his mechanical knee so far in front of the line that weight bearing on this alignment would certainly cause the patient to feel unstable and possibly collapse. Even if the patient could stand on this alignment it would create a lordosis or arching of his lower back. He would be in pain in no time as his lordosis compensates for the lack of hip flexion aligned onto this prosthesis.
The weight line on the picture on the right shows it bisecting the socket and going slightly anterior to the center of his mechanical knee and down to the middle of his foot creating an inherently stable alignment from which the patient can feel safe ambulating on.
George is an American Board Certified Prosthetist with over 25 years of experience focused solely in the practice of prosthetics. As the Director of Prosthetics for Collier, he is responsible for lower and upper extremity prosthetic patient care. His experience ranges from infancy to geriatrics.