Fabrication Instructions for Finger MCP

Fabrication Instructions for
Finger MCP-Stabilizing Orthosis for Ulnar Drift
These instructions correspond to the similarly named video file.
Prepared by Pat McKee
Associate Professor
Department of Occupational Science and Occupational Therapy
University of Toronto
[email protected]
416-978-1817
Pat McKee, 2008
Indications
•
Joint (and perhaps also tendon) instability, typical of inflammatory joint disease e.g.
rheumatoid arthritis
Objectives
•
To promote restabilization of the tendon restraints at MCPs To prevent or correct
MCP volar subluxation
•
To prevent or correct MCP ulnar drift and relieve pain
Materials
1. Rectangular piece of clear plastic
2. Black permanent marker
3. 1/16 in (1.6 mm) self-adhesive foam spacers (e.g. Plastazote)
4. 1/6 in (1.6 mm) suggest Ultraperf (13% perforated) Aquaplast Thermoplastic –
coated
5. For the finger supports:
a) 1/16 in (1.6 mm) self-adhesive foam spacers (e.g. Plastazote)
b) 3 pieces of unperforated thermoplastic or thermoplastic pellets
6. 1 in (2.5 cm) wide self-adhesive hook Velcro – 2 pieces
7. 1 in (2.5 cm) wide loop Velcro
Equipment and Tools
1. heating pan
2. spatula
3. heat gun or Butane torch
4. grease pencil
5. lipstick
6. scissors
7. smooth fabric (e.g. pillow case) for drying wet-heated thermoplastic
Joint Positions
•
Position the MCPs in slight flexion to maintain the MCP collateral ligaments on a
slack while enabling the thumb to easily oppose the tips of the index and middle
fingers.
•
If necessary, lift the proximal phalanges to correct the MCP volar subluxation
•
Mold the thermoplastic around the ulnar side of the fifth proximal phalanx and
correct ulnar drift (if appropriate).
•
The wrist, PIPs and thumb are unrestricted.
Pattern
B
A
A. Patterns and Spacers
1. Cut open a clear plastic bag, and cut a hole for the thumb
2. Slide the client’s thumb through the hole, and pull the excess plastic around to
the dorsum of the hand
3. Mark the PIP joint creases of D2-5 and the thenar eminence crease
4. Extend the pattern through the D1-2 webspace, onto the dorsum of the hand, up
the radial side of the index finger and up the ulnar side of the small finger
5. Cut out the pattern from the plastic and check the fit on the client’s hand
6. Transfer the pattern to thermoplastic – draw the outline lightly with a grease
pencil, cutting off all pattern marks
7. Apply 1.6mm (1/16 in.) thick self-adhesive foam spacers (approximately 1 cm x 1
cm) to the ulnar side of D2-4 to act as spacers during the molding process so
that there will be space between the fingers for the finger supports.
B. Molding, Finger Supports and Strap
Molding
1. Place thermoplastic in the heating pan and allow to heat through – water should
be steaming, not bubbling/boiling
2. Use the spatula to lift out of the pan
3. Apply heated thermoplastic to the client’s hand, positioning at the distal edge at
the PIP joints
4. Fold thermoplastic back around thenar eminence
5. Keep client’s hand relaxed to ensure good contour through the transverse arch
6. Maintain slight flexion of the MCP joints
7. Clients with ulnar drift often have volar subluxation of the MCP joints, so during
the molding process lift up on the proximal phalanges and correct the ulnar drift
8. Ensure that the 5th MCP head is cleared and there is unrestricted wrist motion
9. Remove finger spacers and discard
10. Apply lipstick at PIP joint line of fingers - apply orthosis and press fingers into the
thermoplastic to mark trim line for the PIPs
11. Heat distal edge of thermoplastic, reapply to the client’s hand and fully flex each
PIP joint to fold the distal edge of the thermoplastic
Finger Supports
1. Sand inside distal edge of orthosis to remove
coating and prepare for bonding of the finger
support
2. Heat unperforated thermoplastic pieces and
mold around volar and ulnar side of D2-4
proximal phalanges and allow each support to cool
3. Mark the web spaces of D2-4
4. Sand coating off of each finger support and dry heat the volar to bond to orthosis
5.
Strap
1. Apply a patch of hook Velcro to each side of the opening of the orthosis
2. Melt a few rows of the hook Velcro® at the edges that are vulnerable to peeling
away from the orthosis using a heat gun or torch, while protecting the remainder
of the hooks (not shown on video)
3. Apply 1 in (2.5 cm) wide loop Velcro strap across the dorsum of the hand
C. Alternate Finger Supports with the Thermoplastic Pellets
1. Put thermoplastic pellets in hot water – they
will turn clear when heated through
2. Gather the pellets – they will stick together
because they are uncoated
3. Mold pellets into a solid mass and form 3
finger supports coming up from a base of
thermoplastic
4. To adhere the finger supports to the
orthosis – sand the coating off the recipient
area of the orthosis, then dry heat the same area
5. Dry heat the base of the finger supports
6. Place orthosis on client’s hand and pull the warm thermoplastics of the finger
supports up between the fingers and mold over the ulnar and dorsal side of each
finger to create the support
7. Cut off the extra material while thermoplastic is still warm
8. Check fit of the orthosis
Wearing Regimen
•
All the time to prevent/correct deformity and reduce inflammation or just for night
use.
•
Continuous use for several weeks or months can sometimes permanently correct
mild subluxation
Precautions
•
Ensure full clearance of the PIPs, thenar eminence and uninvolved MCPs.
•
Ensure the strap is easy to manage for arthritic fingers.
•
Immobilization of the MCPs puts more stress on the PIPs and DIPs, which could
aggravate inflammation in susceptible arthritic joints.
Options
•
Only limit flexion at MCPs
demonstrating
inflammation/deformity, as
shown right where only D4 &
5 are stabilized.
•
Convert the pattern into a
thumb-hole design.
•
If thumb CMC is also
unstable, alter pattern to stabilize the thumb CMC.

Download Report