Exam 5: Prosthetics TransTib ReadGuide/Lecture/Chart, Suspension Flashcards
What is the main goal of any type of suspension?
(3 points)
- suspension is the method by which the prosthesis is held to the limb
- Keep the limb in contact with the prosthesis
- When prosthesis is suspended perfectly, there is no relative motion between the socket and limb. When motion occurs because of a faulty or inadequate suspension system, the limb is subjected to pistoning.
What is a Waist Belt suspension?
What is it: connected by an elastic strap to the thigh corset (or other socket I think); encircle the pelvis between the iliac crest and the greater trochanters; have adjustable belts with buckles and an inverted Y-strap that is attached to the socket; have an elastic component to accommodate for motion at hip and knee
**older, less common
Waist Belt: Indications (2-3)
Indications: for early transtibial sockets; Good if large volume changes are expected.
May be used for an obese pt (class notes).
Waist Belt: Advantages (2)
Provides auxiliary suspension & decreases pistoning
Waist Belt: Disadvantages (4)
- Cumbersome to don and doff;
- Poor cosmesis;
- tension must be had in order to prevent pistoning- tension decreases hip flexion- straps
- must be loosened in order to sit
Joint and corset: What is it?
What is it: skillfully molded corset that can gain purchase over the smaller circumference of the thigh (just proximal to the knee joint); stiff leather corset- straps or laces that can be tightened as the prosthesis is donned.
Transfers some weight bearing to the thigh.
Includes a metal knee joint that can help with mediaolateral stability of the knee.
*Rarely used anymore
**older, less common
Joint and corset: Indications (2)
Indications:
- Good for short Residual Limb
- good for ligamentous instability in the knee
**rarely used anymore.
Joint and corset: Advantages (2)
- is somewhat load bearing.
- Provides ML knee stability (“may be the suspension of choice for ligamentous instability in the knee”)
Joint and corset: Disadvantages (2)
- Hot Initially;
- Poor Cosmesis
Cuff Strap: What is it?
**Also called supracondylar cuff
What it is: flexible leather cuff that attaches to the medial and lateral walls of the socket at the same point that orthotic knee joints would attach (just posterior and proximal to the anatomic knee center); has adjustable strap that completely encircles that thigh just proximal to the patella; the anatomical structures that provide suspension- patella and femoral condyles; for stronger hold- lower medial and lateral walls
**older, less common
Cuff Strap: Indications (1)
Indications:
- Longer, traumatic residual limb
**Almost no one would get this anymore
(also called Supracondylar Strap)
Cuff Strap: Advantages (5)
Advantages:
- Simple,
- durable,
- Easy to don,
- Volume changes have less impact
- Does not get as hot as some of the others
**Almost no one would get this anymore
(also called Supracondylar Strap)
Cuff Strap: Disadvantages 4)
- Tight, not so appropriate in presence of marginal circulation;
- reduced medial and lateral stability- not good for person with instability or shorter limbs;
- may be a problem for persons with much muscle or adipose tissue around the lower thigh
- Doesn’t look cool!
**Almost no one would get this anymore
(also called Supracondylar Strap)
List the transtibial suspension methods we discussed or are in the book: (10)
- Waste Belt
- Joint and Corset
- Cuff Strap (Supracondylar Cuff)
- Supracondylar
- Supracondylar Suprapatellar
- Sleeve
- Suction
- Locking Liners
- VASS (vacuume assisted socket suspension)
- Elevated Suction
Which suspension systems did Dr. Mincer say were “kinda old and less common” now? (5)
- Supracondylar
- Supracondylar strap (cuff strap)
- Supracondylar Suprapatellar
- Waist Strap
- Corset
**she said Sleeve Suspension was not so old, but I’m not sure if it qualifies as a newer suspension.
Which suspension systems did Dr. Mincer say were the “newer suspensions”? (4)
- Pin and Shuttle (a type of locking liner suspension)
- Suction
- Vacuum Assisted Socket Suspension (VASS)
- Sleeve?
**she said Sleeve Suspension was not so old, but I’m not sure if it qualifies as a “newer suspension.”
Supracondylar suspension: what is it?
What is it: is achieved by incorporating the femoral condyles within the rigid transtibial socket; extends medial and lateral trim lines- makes medial-lateral narrower at knee joint (prevents the knee joint from moving upward out of the socket by capturing the femoral condyles)
Points from class:
- not the same as supracondylar strap
- comes up above the condyles and indented in
- A couple ways to do don:
- Use removable wall: put leg in socket with removable wall piece off, then put removalble wall peice on (See picture)
- Use soft socket: first don soft socket, then put soft socket with limb into the hard socket
(the one in the picture has a removable wall in order to be able to slide the condyles into the socket before replacing the removable part to lock over the condyles)
**older, less common
Supracondylar suspension: Indications (1)
- May require good dexterity, depending on specific model
Two ways to don a supracondylar suspension:
A couple ways to do don:
- Use removable wall: put leg in socket with removable wall piece off, then put removalble wall peice on (See picture)
- Use soft socket: first don soft socket, then put soft socket with limb into the hard socket
Supracondylar Suspension: Disadvantages (3)
- Doesn’t accommodate well to changing volume;
- difficult to don bc of the width of the proximal opening is smaller than the width of the condyles;
- can be apparent though clothes (cosmesis issue)
When referring to suspensions, SC stands for what?
supracondylar
(specifically a supracondylar suspension)
Supracondylar suspension: advantages (1)
- Minimizes vascular problems because it doesn’t have a cuff that goes all the way around thigh
**DOES NOT provide significant mediolateral stability (despite what pg 631 of the book says). Dr. Mincer was very clear about this in class. It might provide a slight amount of mediolateral stability, but not enough to matter or for us to care about.
What is not an advantage of Supracondylar Suspension?
**DOES NOT provide significant mediolateral stability (despite what it says on pg 631 of book). Dr. Mincer was very clear about this in class. It might provide a slight amount of mediolateral stability, but not enough to matter or for us to care about.
What is it called when supracondylar suspension is combined with a PTB-style socket?
PTB-SC socket
Supracondylar suprapatellar suspension: what is it?
It is like a PTB-SC socket with the trim line of the anterior aspect extended to the proximal surface of the patella.
Then it is called PTB-SCSP (patellar tendon-bearing supracondylar/suprapatellar); and allows the formation of a quadriceps bar above the patella that provides suspension and resists hyperextension
Basically like a supracondylar suspension that is extended to the superior part of the patella
**older, less common
What does PTB-SCSP stand for?
Patellar Tendon Bearing - Supracondylar Suprapatellar
Type of socket suspension
Supracondylar suprapatellar: indications (1)
Indications: not appropriate for heavy thighs
Supracondylar suprapatellar: advantages (2)
- Minimizes vascular problems;
- may provide some ML knee support (but not enough to really matter - Dr. Mincer)
Sleeve suspension: what is it?
What is it: provides suspension through 2 biomechanical principles- friction and vacuum (book says this but later says only friction); sleeve is approx 20 cm prox and distal to knee center and fitted over the proximal end of the prosthetic socket; should fit snugly without hindering circulation. Uses friction only to suspend prosthesis because they allow air to flow through them.
Materials:
- Standard has been neoprene (like wet suit)
- There are now some silicone sleeves (dr mincer)
**one of the most versatile means of suspending a prosthesis
***not in the old, uncommon category; not sure if it is “new” either
What is critical about socks when using a suction suspension?
The sock must not be too long!
The sock must come above the proximal trim line, but not much higher. The sock is ouside the gel liner but inside the hard socket and sleeve. The gel inside surface of the sleeve and the gel outside surface of the gel liner must touch to make a seal. If the sock is too long, it will prevent this.
What looks like an intersting place to visit in Romania?
Peles Castle
Locking Liner, strap method
- describe it
- Good for/Advantages
- Problems
- strap: difficulties with the ring gave rise to the strap; strap manually fed through at the distal end of the socket and then secured to the outside of the socket; strap must be long enough.
- Good- the limb will be secured in sleeve once the strap is tightened (don’t have to be as worried about careful placement), requires less force to don, no additional clearance needed
- There is a variant of this system that uses a lanyard and a spacial lock mechanism to secure the lanyard in the distal end of the socket. The lanyard is permanently attached to the locking mehcanisms so it needs to be disconnected from teh liner each time the liner is taken off
Locking Liner, pin-and-lock method
- describe it
- Good for/Advantages
- Problems
- pin-and-lock: pin can range from 3 to 10 cm in length; pin works with a locking mechanism;
- pt can learn how many clicks are normal for them when donning
- can be frustrating to try and align the pin and locking mechanism; need to be able to disengage pin while pushing the socket off with the other hand
What looks like a fun thing to visit in Aiken, SC?
Aiken Steeplechase (Spring or Fall)
(unless lots of people get hurt)
What is alignment for a trans tib prosthesis?
Prosthetist stands prosthesis up on a table (bench) and looks at the alignment of the socket relative to the foot (and pilon)
bench alignment serves as the starting point for the dynamic alignment process
What is transtib socket flexion?
tilting the proximal end of the socket anteriorally (like how it would move in knee flexion)
what is transtib socket extension?
tilting the proximal part of the socket posteriorally (like how it would be in knee extension)
Where is a place I would want to take you if you came to Bend, OR
Lava River Cave
What is transtib socket abduction?
proximal socket moves medially (like if wearer had genu valgum)
what is transtib socket adduction?
proximal part of the socket tilts laterally (like if pt had genu varum)
