5: Transtibial Flashcards
What type of flap is typically used for transtibial amputation and why?
Long posterior flap because of good vascularization and provides good weight-bearing surface
What is specifically done to the fibula during transtibial amputation surgery?
Is is transected 1-2 cm shorter than the tibia to avoid distal fibula pain
What is a short transtibial amputation?
Less than 20% of the tibia is preserved
What are the results of a short transtibial amputation?
Small moment arm that makes knee extension difficult
What is a standard transtibial amputation?
Between 20-50% of the tibia length is preserved
What is required for a standard transtibial amputation for optimal prosthesis fit?
At least 8 cm of tibia required below the knee joint
What is a long transtibial amputation?
More than 50% of the tibial length is preserved. Not typical due to poor blood supply to the distal leg
What is an Ewing amputation?
During surgery, AMIs are created by linking muscle pairs within the residual limb
What does AMI stand for?
Agonist-antagonist myoneural interface
What is the purpose of an Ewing amputation?
Provide proprioceptive feedback and better control of prosthetic device
What are the 5 pressure sensitive areas for a transtibial amputation?
- Fibular head
- Shin bone
- End of fibula
- End of tibia
- Hamstring tendons
What are the two socket designs for a transtibial prosthesis?
Patellar tendon bearing (PTB) and total surface bearing
What are the four suspension systems for a transtibial prosthesis?
- Thigh corset
- Pin system
- Suction suspension
- Vacuum assisted socket system
Describe the patellar tendon bearing (PTB) socket
Has an indentation over the patellar tendon with specific pressure points. Most basic design
Where is suspension generated with a PTB?
At the medial and lateral areas of the femoral condyles
What type of socket is shown in the image?
Patellar tendon bearing (PTB)
What type of socket is shown in the image?
Total surface bearing