Transfemoral Problem Solving

Question 1

List possible causes of medial brim pressure in the quadrilateral transfemoral socket.

Answer 1

• anterior-posterior dimension too wide, ischium fall into socket
• medial brim too wide or radius insufficient
• medial-lateral dimension too small
• medial wall too high
• unaccommodated adductor roll

Question 2

What are the indications for a polycentric style knee?

Answer 2

• the need for inherent stability
• more closely matching the anatomic knee center for knee disarticulation amputation
• short residual limb or hip disarticulation

Question 3

What is an indication for a single-axis foot in the transfemoral amputee?

Answer 3

• weak hip extensors

- knee stability

Question 4

How do you instruct the patient to activate the free-swinging feature of the Mauch S-N-S hydraulic knee?

Answer 4

Hyperextend the knee and flip lever up

Question 5

List possible causes of transfemoral socket rotation during gait.

Answer 5

• muscle bellies are unaccommodated for in socket contours
• inadequate suspension
• knee axis alignment incorrect
• shoe heel too firm
• socket not donned properly
• socket too loose

Question 6

How do you bench align a prosthesis when the patient exhibits a 10 degree hip flexion contracture?

Answer 6

Place the socket into 15 degrees of flexion

Question 7

What two types of contractures are most commonly present on the involved side of the transfemoral amputee?

Answer 7

• hip abduction

- hip flexion

Question 8

Order the following knees from most stable to least stable:

Weight activated stance control, single axis constant friction, polycentric knee, locking knee

Answer 8

• locking knee
• weight activated stance control
• polycentric
• single axis constant friction

Question 9

A patient presents with a soft fleshy mid-length transfemoral amputation. She has no other issues that would contradict prosthetic fitting. What suspension would you consider for this particular patient?

Answer 9

Suction suspension with an auxiliary Silesian belt to control socket rotation about the soft tissue.

Question 10

List advantages of the quadrilateral socket.

Answer 10

• total contact provides venous return and proprioception
• each wall serves a specific function
• supports anatomical structures