Study Material Flashcards
Transhumeral Cabling System
Fair Lead
- Split Cable housing
Transradial Cabling System
Bowden
- Single Cable Housing
Krukenberg Amputation
- bilateral transradial amputations
- visually impaired
Anterior Cruciate Ligament
- back and forth motion of the knee
- posterior lateral distal femur to anterior medial proximal tibia
Posterior Cruciate Ligament
- posterior stabilizer of the knee
- anterolateral aspect of the medial femoral condyle to posterior aspect of tibial plateau
Upper Prosthetic Limb Length
Lateral epicondyle to thumb tip
Figure of 9 Harness
Terminal device activation only
Figure of 8 Harness
Suspension needed
Terminal device function
Rigid Hinge: Single-Axis
- protects RL from excessive torque loads
- extension stop prevents elbow hyperextension
Wrist Shapes
- Circular base more anatomical (WD or Long transradial)
- Oval base (mid length to short transradial)*
Step Up Hinge
- 2:1 ratio between forearm and residual limb
- requires 2x the force to fully operate
Flail Arm Hinge
- brachial plexus injury
- ROM is present, strength not present
Flexible Hinges
- medium to long TRs
- allow pronation/supination
- do not protect against torque
Required excursion to fully open TD from fully closed position:
2 inches
UE Self-Suspending Sockets
- prevent rotation by surrounding the medial and lateral epicondyles of the elbow
- northwestern, Otto bock, muenster
Long Transradial Shape
- ellipsoidal shape
- can prevent socket rotation
- screw-driver effect
Short Transradial Shape
- circular
- allows axial rotation
UE Self-Suspension Styles
- Supra-styloid (allows axial rotation)
- Supra-epicondylar (prevents axial rotation)
Elbow disarticulation amputation
- Humerus remains generally intact along with articular cartilage
- May include moderate contouring of the humeral condyles
- Soft tissue distally should be minimized for suspension/rotational control via humeral condyles
RL Length for Elbow Disarticulation
Max elbow discrepancy - 2 inches
Transhumeral Shape
- “D” shape in axilla
- Round in mid-humeral region
- Bulbous asymmetric shape at distal end
Dual Control System
Fair-Lead Split Housing (two-piece)
- Elbow flexion 2.5”
- Complete TD opening 2”
Elbow Lock cable
- 5/8”-3/4” excursion
- 2 lbs. force
Forearm Lift Tab Jig Operation
- closer to the elbow axis, more body power required, but cable excursion decreases
- farther away from the elbow axis, less body power required, but cable excursion increases
- initial placement: 3rd hole distal to the elbow axis on the bottom row
Humeral Base Plate Placement
- Middle of the humeral socket
- 50% or longer than the anatomical length
- Distal end of inner socket
- shorter than 50% of anatomical length
*Minimizes “adduction” torques on the px
Transhumeral Control Motion Sequence
- flex elbow to desired ROM
- lock elbow shoulder: depression, extension, and abduction
Carlyle Index (Bilateral Arm Amputee)
- Upper-arm px length = height (in) x 0.19
- Forearm px length = height (in) x 0.21
Forearm Lift Assist
- placed on the medial side to allow patient adjustment
- ideal for short ?? and shoulder disarticulations due to limited force generation secondary to weakening or pain
Excursion Amplifier
- 2x the force input generates 2x the excursion
- mount to posterior brim of socket
Shoulder Disarticulation/IST Disadvantages
- pressure sensitive
- excursion generation
- balance (arm ~ 4.9% of body weight)
Knee Joint
Polycentric hinge - rolling and sliding action
- Med Roll: first 10-15 degrees
- Lat Roll: roll for 20 degrees
Screw-Home Mechanism
Tibia
- internal rotation during knee flexion
- external rotation during knee extension
KAFO Clearance Guidelines
Perineum (30 mm or ~ 1") Knee - Medial: 6 mm - Lateral: 3 mm - Drop Locks: 3 mm Ankle (Ht.: Apex of lateral malleolus) - Medial: 6 mm - Lateral: 5 mm
Cervical Vertebrae Characteristics
- Transverse foramen present for blood supply
- Vertebral foramen is large and triangular
- C3-C6 have bifid spinous processes
Thoracic Vertebrae Characteristics
- Spinous process is spine like and is close to vertical
- Body is heart shaped
Lumbar Vertebrae Characteristics
- Spinous process is large, oblong and horizontal
- Vertebral foreman is small and triangular
- Body is kidney-shaped and longer transversely
Intertransverse Ligament
- Connect transverse processes
- Assist in controlling lateral bending
Spondylolysis
Bony defect at the pars interarticularis, which may be unilateral or bilateral.
Spondylolisthesis
Forward slippage of one vertebrae upon the other. (L5)
Jefferson’s Fracture (Diving Accident)
- 4 part burst fracture of Atlas (C1)
- axial compression, hyperextension
Odontoid Fracture
- Type I Avulsion of alar lig. off one side of tip of dens.
- Rigid Collar
Type II (most common) Fx through base of odontoid via hyper flex or ext - Halo
Type III FX extends through body of C2
- Halo
Hangman’s Fracture
- Fx of pars interarticularis of C2
- Forceful extension of extended neck
Chance Fracture
- “seatbelt” injury mechanism
Spinal Orthosis Selection: T7-L3
TLSO Corset - Custom TLSO
Spinal Orthosis Selection: L1-L3
LSO Corset - Custom LSO
Spinal Orthosis Selection: L4-S1
LSO Corset - LSO Fracture Cast w/ Spica
Adams Forward Bending Test
- Spinous process rotate to the curve’s concavity, vertebral bodies to the convexity.
- Thoracic: Rib prominence
- Lumbar: Paraspinal prominence
Scheuermann’s Kyphosis
- interruption of endochondral ossification, leading to anterior wedging and increased kyphosis
- typical presentation around ages 10 to 12
- marked increase kyphosis upon forward bending
Zig Zag Deformity
- Radial deviation
- Rheumatoid arthritis
Buerger’s Disease
- Acute inflammation and thrombosis (clotting) of arteries and veins
- Affects the hands and feet
- 20-40 y. o. male cigarette smokers
Syme PTB Mod. Location
Lower than TB
- Heel off forces are on the patellar tendon instead of the on the crest of the tibia.
Anterior - Posterior
TB PTB Socket Forces
- popliteal
- distal tibia
Medial - Lateral
TB PTB Socket Forces
- medial tibial flare
- distal lateral socket
Adduction
TB Prosthetic Alignment
- distal medial increase
- varus knee
Abduction
TB Prosthetic Alignment
- distal lateral increase
- valgus knee
Px Joint and Corset Goals
- redistribute some residuum pressure on to thigh
- increase ML knee stability
- prevent genu recurvatum
- suspension (waste belt and fork strap)
TB Px Joint Attachment
- 2.25” proximal to MPT
- Socket midline
TB Px Corset Clearance
- 1” clearance between distal posterior aspect of the corset relative to the socket while sitting at 90 degrees
TB Endoskeletal Construction
Indications
- need for interchangeability of components
Advantages
- alignment adjustability after fabrication
Disadvantages
- requires more maintenance
TB Exoskeletal Construction
Indications
- appropriate for virtually all def. BK prostheses whether usage will be light or heavy duty
Advantages
- easy to keep clean
Disadvantages
- alignment is not adjustable without major fabrication
PTB Socket w/ Soft Liner
Advantages
- soft protective socket interference
- appropriate for the majority of residual limbs
Disadvantages
- not as hygienic as a hard socket
- increases bulk around the knee
PTB Hard Socket
Advantages
- less bulky at the knee than with an insert
- easy to keep clean
Disadvantages
- requires precision in casting and modification
Supracondylar Cuff Placement Location
- 12 mm proximal to MPT
- 12 mm posterior to a vertical line bisecting the A/P of the socket
Knee Disartic Advantages
- long lever arm and preserved musculature
- more balanced musculature
Quadrilateral Socket: Medial Wall
- pressure on adductors
- contain medial tissues
- line of progression
Quadrilateral Socket: Anterior Wall
- surface over which to distribute anterior forces
- Scarpa’s bulge
Quadrilateral Socket: Posterior Wall
- height refers to height from floor to ischial level
- 5-11 degree shape
Ischial Containment Principles: STML
Soft Tissue M/L
- derived from table based on circumferential measurement at 1” level
Ischial Containment Principles: Medial Wall Containment
- angled to match ischial-ramus angle
- prevents medial migration of ischium in socket
Ischium Location
Quadrilateral
- on brim
Ischial Containment
- in socket
TF Knee Center Alignment
Single Axis Knee
- 1/4” posterior to T-A line
- posterior to the T-A line, depends on type
Normal Step Length
Foot reaches 15 degrees behind vertical line originating at the hip.
- 3 degrees pelvic rotation (lordosis)
- 5 degrees hip extension
- 7 knee flexion
TF Hip Contracture
Add the amount of contracture to the 5 degrees of socket flexion needed for normal step length
Hip Disarticulation
Disarticulation at femoral head/acetabulum
HD Advantages
- ischial tuberosity is retained, will tolerate loading well
- balance and comfort for sitting is better than the hemipelvectomy
- ilium is retained - suspension, rotational control, pressure tolerant region
Transpelvic Management
Amputation at junction of sacrum/ilium Other Names - hemipelvectomy - hindquarter amputation - transiliac
Transpelvic Issues “Advantages”
- retains bowel, bladder, and sexual function
- life-saving procedure
- good px rehab among young patients
- pregnancy and successful delivery still possible
Transpelvic Issues “Disadvantages”
- weight bearing of IT is lost
- suspension and rotational control are much more difficult to achieve
- energy expenditure 200% of normal ambulation
- usually require crutches and cane for ambulation
- scoliotic changes may result over time
- more prone to postoperative infections
- issues with hygiene due to defecation and urination control
Scarpas Triangle
- inguinal ligament superiorly
- adductor longus medially
- sartorius laterally
