General Prosthetic Questions for ABC Written Exam Questions With Correct Answers

Bench Alignment for TT - Answer - 5*to 10* flexion -2* to 5* adduction -1/2" to 1" inset -3* to 5* outward rotation or parallel to the LOP -37mm posterior (18-65mm range) -1/4" anterior from ankle bolt to midline Bench Alignment for TF - Answer - 5* flexion + flexion contracture - Long's line + 2* to 5 * -outset foot 1" from ishium + 1*-2* ext -5* external rotation of the knee Cuff strap placement - Answer -1cm posterior and 1cm proximal to midline at PTB level Silesian Belt placement - Answer -1/4" posterior and proximal to G.T. (Lateral) -1/4" proximal and medial to bisection (Anterior) Scrapa's Triangle - Answer -Ingiunal Ligament -Sartorious -ADDUCTOR Longus Cycle the Elbow in TH prosthesis - Answer -3/4" excursion - 2lbs force Operation of TD and Elbow lift (Excursion) - Answer -2 1/2" to lift elbow -2" for TD Starting point for EFA - Answer - 1" distal and 1" anterior to elbow center Hip Bench Alignment - Answer -joint anterior to knee center 25-50mm -reference line knee center to 37mm posterior to heel -1/2" anterior and 1" proximal to GT Subischial Triangle - Answer -Inferior Pubic Ramus -Gracilis -Semitendenosis Adduction of the lateral wall of the socket - Answer Re-establishes the normal angulation (6-7*) of the femoral shaft, thereby placing the hip abductor muscles under their normal operation tension Proper contouring of the lateral wall - Answer -Allows for even distribution of force over the lateral aspect of the residual limb, specifically between the greater trochanter and the lateral distal aspect of the femur -Relief for the lateral distal end of the femur and for GT High medial wall - Answer -Proximal medial wall must be high enough to apply counter pressure to maintain good contact between the femur and the lateral wall Proper mediolateral dimension of the socket at ischial level - Answer -too large an ML will reduce the effectiveness of the lateral and medial walls to stabilize the femur -Divide the circ of the thigh by pi and subtract 1/4" Proper anteroposterior dimension of the socket - Answer -too large an AP will tend to permit the IT to be displaced forward, off of the ischial seat. -correct AP determined by subtracting 1/2" from the anatomically determined distance between the ADDUCTOR longus tendon and the IT Pressure on Scarpa's Triangle provides - Answer -relieves pressure at initial contact -comfort for sitting -relieves the ADDUCTOR longus tendon -controls rotation -keeps pelvis from rotating -IT on the seat Anterior-posterior forces - Answer -concentrated in the anterior distal tibia and posterior proximal soft tissue -Socket provides even pressure distribution in the popliteal area and anterior distal relief to prevent excessive pressure Media-lateral forces - Answer -forces at the proximal medial and distal lateral area force a varum moment at midstance -Socket must have relief for the distal lateral fibula and lateral stabilizing pressure over the shaft of the fibula and anterior compartment. Sheer force - Answer -Occurs when the socket moves in a direction opposite to the residual limb's motion. Torque - Answer -Tendency of the socket to rotate on the residual limb Joint Location for TT J&C designs - Answer -2 1/4" inches superior to the patella tendon protuberance, and slightly posterior to the sagittal midline. -joints must be square to each other and an equal height from the floor -line through JCs would be roughly perpendicular to LOP -slight anterior tilt -extension stop strap can prolong joint life. Corset Location and Configuration - Answer - generally 8" long -Proximal lateral border 1" higher -Anterior distal edge is proximal to patella -opening is 1" wide - When sitting tissue should not be pinched between proximal socket wall and distal corset aspect. 1" clearance needed. Transradial Amputation Levels - Answer -Long: 55-100% -Short: 35-55% -Very Short: 0-35% Voluntary Opening TD - Answer -Closed at rest -Body motion and effort used to open TD -Max force regulated by the # of rubber bands or springs (1 rubber band = 1lb of pinch force) -requires 2 1/2 times the pinch force to open the TD Voluntary Closing - Answer -Open at rest -Body motion and effort used to close the TD -Max force regulated by the patient effort and the mechanics of the device -requires user to overcome the spring/elastic cord NYU-Muenster - Answer -A-P compression -short to very short limbs -light to moderate duty -unilateral -LL =1 1/2" to 5 1/2" -achieve 70* ROM from 35* to 110* Northwestern Design - Answer -Supracondylar suspension -low anterior timelines -longer limbs, greater than 55% -good for bilaterals Otto Bock - Answer - mid range limbs -M-L & A-P compression -dynamic casting technique Elbow Flexion Attatchment Adjustment - Answer -more proximal = less required excursion -more distal = less required force Proximal Base Plate Retainer - Answer -more posterior and distal = less required excursion -more proximal and lateral = less required force -must be 25mm proximal to the cut end of the humerus Cable Housing and Length - Answer -Cable Length -- extend arm and pronate TD (3mm clearance between hangar and proximal housing) -Housing Length -- flex elbow, supinate and open TD (3mm clearance between triple swivel and distal housing, 6mm clearance between proximal and distal housings at the elbow joint) Force Problem -- when flexing the elbow joint, the TD begins to open - Answer -add tension bands -move EFA distal -move BPR lateral and proximal -add spring lift assist -add second BPR -lighter TD -shorten forearm -check cable efficiency -check proximal and distal fair lead upon flexion