MIDCARPAL INSTABILITY - U of T Division of Plastic
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Transcript MIDCARPAL INSTABILITY - U of T Division of Plastic
Therapy for Challenging
Wrist Conditions
Marianne Williams B.Sc.P.T., CHT
Objectives:
• To discuss the therapy interventions for
some wrist instability patterns
ANATOMY
• Intrinsic wrist ligaments
– Volar
– Dorsal
• Extrinsic wrist ligaments
– Volar
– Dorsal
Intrinsic Wrist Ligaments-Volar
Intrinsic Wrist Ligaments-Dorsal
Extrinsic Wrist Ligaments-Volar
Capito-triquetral lig
Radio-scapho--capitate lig
Extrinsic Wrist Ligaments-Dorsal
Radio-triquetral lig
Classification
• Carpal Instability Dissociative (CID)
– A dissociation within the interosseous ligaments
• Carpal Instability Non-dissociative (CIND)
– Instability of a carpal row as a whole
• Carpal Instability Complex (CIC)
– A combination of the 2 dissociations
• Carpal Injury Adaptive (CIA)
– Secondary changes in the carpus which results
from a non-union or malunion of the distal radius
or carpal bones
CID - Pathomechanics
• The proximal carpal row is the most common
site
• The scapho-lunate ligament disruption and
subsequent scaphoid rotatory subluxation is
the most common ligament injury pattern of
the wrist
• The clinical picture may range from complete
dislocation to a subtle form of dynamic
instability
• The carpal mal-alignment results in increased
stresses on the radio-scaphoid and capitolunate joints
Clinical Evaluation
• ROM
• Grip Strength
• Palpation over the Scapho-lunate(SL)
ligament
• Special tests :Watson’s test, SL
Ballottement test
• X-ray
Therapy Considerations
• Kinematics:
• As the wrist extends, there is a
tendency for the scaphoid to supinate
and the lunate to pronate, which
effectively separates the palmar
surfaces of the 2 bones.
• The reverse occurs in palmar flexion
» Berger 1996
Therapy Considerations (cont’d)
• Kinetics:
• The radial side of the wrist is
responsible for the major load transfers
across the wrist. In wrist neutral and
neutral forearm rotation, 80% of the
force is transmitted across the
radiocarpal joint and 20% across the
ulnocarpal joint with gripping.
» Berger 1996
CID-Therapy Intervention
•
•
•
•
Comfortable AROM
No PROM into end range
No repetitive gripping
Isometric vs isotonic strengthening
Post-Operative Therapy
• When ligaments are repaired, the patient may
be immobilized for up to 8 weeks
• Length of immobilization after a partial fusion
is dependent upon radiographic healing
• Initially AROM is started then PROM for
extension sooner than flexion. PROM is for
physiological range not accessory motion.
• Therapy goals need to parallel the surgeon’s
goals
Post-Operative Therapy (cont’d)
• Functional wrist ROM is 40/40 for
flexion and extension.
» Wright et al, 1996
• Principles of strengthening are based
on the kinetics. Initially start with
isometrics and retraining the wrist
extensors. Gradually progress to
concentric strengthening. Grip
strengthening is introduced judiciously.
Luno-triquetral Instability
• Less common than the SL ligament
dissociation
• Alter the special tests in your clinical
examination to this region
• Similar approach by Surgeon and
Therapist for both conservative and
post-operative interventions as in SL
dissociation
CIND: Clinical Characteristics
• Volar sag on the ulnar side of the wrist
• Painful clunk which occurs at the end
range of ulnar deviation
• Tenderness over the triquetral-hamate
and capito-lunate intervals
• Weakness of grip
Pathoanatomy
• Ligamentous laxity or disruption results
in the following:
– Volar flexed orientation of the proximal
carpal row in neutral deviation
– Palmar translation of the distal carpal row
• Ligaments involved:
– Ulnar arm of the volar arcuate ligament
– Dorsal radio-triquetral ligament
Pathomechanics
• Loss of intimate midcarpal joint contact
• Loss of the smooth transition of the proximal
carpal row from a flexed to extended position
as the wrist moves from radial to ulnar
deviation
• As the wrist moves from radial to ulnar
deviation, the proximal carpal row stays
flexed and the distal carpal row remains
palmarly subluxed until the end range of ulnar
deviation
Pathomechanics (cont’d)
• A painful “clunk” occurs at the end
range of ulnar deviation which
represents abrupt snapping of the
proximal carpal row into extension and
reduction of the palmar translation of
the distal carpal row.
» Wright et al ,1984
Clinical Evaluation
• Palpation over the triquetral-hamate and
the capito-lunate intervals
• Midcarpal shift test (Lichtman)
• Passive translation of the midcarpal
joint while stabilizing the distal forearm
and applying a palmar or dorsal directed
force to the carpus
CIND-Conservative Management
• This is attempted initially
• Immobilize – cast for 6 weeks
• Then wrist cock-up splint and initiation
of AROM
– PROM OFTEN NOT NECCESSARY
Midcarpal Stabilization Splint
• Dorsally directed
pressure on the
pisiform reduces the
ulnar sag and
corrects the volar
flexed position of the
proximal carpal row
• Midcarpal dynamics
are corrected and
wrist clunk is
eliminated
Midcarpal Stabilization Splint
• Splint allows
nearly full
extension, radial
and ulnar
deviation and
limits flexion
Midcarpal Stabilization Splint Pattern
Exercise Approach
• Midcarpal joint pathomechanics might
also be corrected by dynamic muscle
action
• Dynamic muscle compression achieved
by activation of the flexor carpi ulnaris
(FCU) and the hypothenar muscles
reproduces the normal joint contact
forces in the absence of adequate
ligament support
Abd DM
FCU
ECU
Abd DM
ECU
FCU
Exercise Approach (cont’d)
• Strengthening of both FCU and ECU,
would seem to be important in
counteracting the volar sag that occurs
prior to moving into ulnar deviation
• Position of the forearm – supination
• Isometric vs Isotonic exercises
Case Presentation
• 22 year old right-handed cashier with
idiopathic right dorsal wrist pain
• Diagnosis: Midcarpal Instability
• Right wrist was immobilized in a cast x6/52
• April 22, 2003 Right wrist cock-up splint
fabricated and patient initiated AROM
exercises
• Sept 17,2003 midcarpal stabilization splint
made for the right wrist
PRWE Results
• Sept. 17,2003
Pain: 37/50
Function: 29.5/50
Total: 66.5/100
– Right midcarpal stabilization splint made
• Nov. 4, 2003 Pain: 22/50
Function: 11.5/50
Total: 33.5/100
Surgical Intervention
• At our centre the approach is dorsal
• The Hand Therapist should be
cognizant that if a procedure is
designed to stabilize tissue and the
prolonged post-operative immobilization
is to limit motion, then therapy principles
should parallel these goals.
CIC-Perilunate Dislocation
• Surgery is the most successful form of
medical management
• Post-operative therapy is similar to that of SL
or LT repair
• However, ligament repairs are more
extensive and more dissection required
• Therefore, long extensor adhesions are more
common
• Significant wrist motion is lost postoperatively
CIA-Carpal Injury Adaptive
• Secondary changes in the carpus have
developed from a non-union or
malunion of the distla radius or carpal
bone
• The pattern is treated by correcting the
deformity eg Distal radius corrective
osteotomy
• This post-operative therapy focuses on
early AROM
Conclusion
“A good axiom to keep in mind is that a
painless, stable wrist with functional
ROM is superior to one with full ROM
that is unstable and painful”
Hendrycks et al, 2001