Anatomy, Biomechanics, Pathomechanics
General description
 Skeletal architecture forms the basis of hand function
o 27 bones of the wrist
o Distal radius & Ulna
 Multiple articulations
o Multiple movements passing multiple joints allows for 3-D activity
 Potential negative side:
 Loss of stability of one segment increases risk of
mechanical dysfunction.
Distal fore-arm interaction
 Radius is broad forming a concave surface with
shallow depression for contacts with scaphoid and
lunate


This articular surface is 11°
palmarly (palmar tilt) sagittal
plane
23° medially (radial
inclination) frontal plane
Distal Ulnar:

The Distal ulna bears a small,
rounded head that forms the
CONVEX articular partner of DRUJ
 Distal articular surface of the ulna
is almost parallel with adjacent
radial surface (Neutral Variance)
 When the ulna lies proximal to the
radius is called (Negative ulnar
variance)
o Associated with lunate
necrosis (Kienbock disease)
 When the ulna lies proximal to the
radius is called (positive variance)
o Increases the risk DJD
triangular fibrocartilage
disk.
* it is important to identify proper
ulnar length.
Quick note: it is essential to restore anatomical
alignment after distal radius fractures
Radial Styloid process projects distally:
 Primary site of attachment for many radiocarpal
ligaments
Division of bones of the wrist and hand:
Lister tubercle:
 Projects dorsally
 Forms a pulley around the EPL
o Common site of wear and tear potential
tendon rupture
1. 8 carpal bones
a. 4 proximal row
b. 4 distal row
2. 5 Metacarpals
3. 14 Phalanges
Specific features characterize the carpal bones
Scaphoid:
Lunate
Triquetrum
Pisiform
1.
Radial side
6. Lateral view long axis
forms a 45° angle palmar
plane
1. Center of proximal row
1.
Adjacent to lunate
1. Pea shaped
2.
Proximal row
3.
Peanut shape
4. Narrow
5. Most
central waist common
fractured
* Blood supply enters the
scaphoid distally through a
leash of vessels in the
dorsal capsule; a fracture
on the waist can render the
proximal pole avascular.
7. Prominent tubercle of scaphoid offers attachment to the flexor retinaculum palpable at the distal crease
2. Medial to the
scaphoid
3. Essential roll in
mobility and stability
of the wrist
4. X-ray quadrangular
on an AP view and
crescent-shaped on
lateral view
2. Pyramid shape with oval face on the volar border during radial deviation
5. A triangular appearance on AP view indicative
of instability or Kienbock disease (avascular
necrosis)
2. Last carpal of
proximal row &
3. Rest of the facet of
triquetrum
5. Offers attachment to:
1. Pisohame, 2. Pisometacarpal ligaments, 3.
Flexor & Extensor retinacula, 4. Addcutor digiti
minimi,
It is a sesamoid bone in the Flexor carpi ulnaris
(palpable landmark)
4. Is the smallest of
carpal bones
Trapezium
1. Lateral side of distal
row
2. Saddle
shaped
3. 1st distal surface forms the critically
4. A volar groove houses
5. A tubercle provides attachment
important 1st carpometacarpal (CMC) Or
the flexor carpi radialis
for the flexor retinaculum.
basal joint of the thumb
(FCR)
3. Articulates distally with 2nd metacarpal (this is the most stable articulation of the wrist)
Trapezoid
1. Medial to the
trapezium
2. Irregular
shaped
Capitate
1. Forms the keystone of
distal row
Hamate
1. occupies the most
medial of distal row
2. Articulates with: 1. It proximal head with scaphoid and
lunate, 2. Distal body with trapezoid, hamate and 2 nd, 3rd, 4th
metacarpals.
3. its prominent hamulus (hook) offers attachment for the
Flexor retinaculum
3. Multiple ligaments attachments to its volar surface
3. Protect the branches of ulnar artery and nerve.
Longitudinal arch
Fixed proximal
transverse
Mobile distal transverse
Runs lengthwise from the wrist to the fingertips
Defined by the volar concavity of the distal carpal row
Is at the level of the met heads





Contributes to powerful grasping
Serves as a stable base for the hand
Forms the bony floor of the carpal tunnel
Allows the hand to adapt to objects held in the
palm
Unique feature enabling one to securely grasp
items that vary in shape from a rope to a softball.
Ulnocarpal ligament and Interosseous membrane:
Structural column formed:

Distal Radius

Distal Ulna,
hand by allowing balanced force transmission through the

Triangular fibrocartilage complex (TFCC)
entire upper extremity

Ulnocarpal ligament

And interosseous membrane

Support the complex and intricate movements of the
20% of force across the ulnar wrist (ulna
80% through the radial wrist
and TFCC)
Small changes in articular contact stress can greatly affect the force of distribution and cause pain.
From full Supination to Pronation : most motion
Radius and Ulna
Uniaxial pivot:
happens at the radius
Radius: moves to lie anteriomedial and slightly
Unite at
- Allows the Radius to ROTATE & GLIDE around the
proximal to the ulna.
DRUJ
relative fixed Ulna.
Ulna: moves in a reciprocal direction posterolaterally
and distal to the radius. This produces a slight positive
ulnar variance during pronation.
DRUJ
TFFC
1.
Radius
2. Ulna
1. Articular disk
3.
= Lax in Neutral
Articular = Volar portion becomes taut in supination
This provides Extrinsic support.
disk
= Dorsal portion becomes taut in pronation
2.Ulnar collateral ligament 3. ECU extensor carpi U. 4. Tendon sheath
5. Meniscus homologue
6. Dorsal radioulnar ligament
7. Volar radioulnar ligament
1.
Apex
attaches
to
ulnar
2.
Base
connects to the ulnar margin of radius
Disk styloid process
The base is shallow concavity = fovea (empty
of cartilage but fully has vascular foramina
that supply vessels to the TFCC)
6. The periphery of the disk is thick
whereas the center is thin
10. Most perforations are degenerative
rather than traumatic
Provides intrinsic joint stability
3. 15-20% is
5. Injuries near the avascular
vascularized this is
radial attachment require
Apex. (Only area
open repair.
treated with
immobilizer)
7. Superior and
8. Disk separates the ulna from
9. Powerful gripping increases the
inferior surfaces are
direct contact with the carpals.
load on the disk and continuous
concave.
loading may subject the disk to
degeneration
11. Disk perforations 50-60% in
12. The disk assist the interosseous membrane of the
people older than 50 years
forearm in connecting the radius and ulna and in
prevention the proximal radial migration.
Injuries such as Essex-Lopresti fracture involve injuries; such as a radial head fracture and DRUJ instability contribute to radial migration.
Link the fore-arm and hand through several associated such as:
Intercalated, Stacked
Force Distributions
Across the Radiocarpal Joints
Carpal Biomechanics
Mobile Row
Triquetrum
Lunate
Scaphoid
Immobile Row
Hamate
Capitate
Trapezoid
Luno-triquetral
Trapezium
ligament
Resting position: neutral
or slight flexion
Close packed position: extension
Proximal row
Distal row
Flexion /
Extension
Radial deviation
Ulnar deviation
Closed pack
position
No extrinsic muscles attach to the potential
less stable carpals, with the exception of the
pisiform. FCU
During axial loading
of the wrist, the
radius bears about
80% of the
compressive load,
the ulna about 20%
Scapho-lunate
ligament
Weakest link in the wrist and the site of most carpal dissociations
Bones are firmly bound together with ligaments and acts as a single unit with minimal motion independent of each
other.
Proximal and Distal
Moved together relative to the radius (according to the convex and concave arthrokinematic
row
principle)
Distal Row
Moves radially with the hand
Proximal Row Moves ulnarly on the radius and flexes
Distal Row
Proximal Row Moves radially and extends
Wrist extension is the CPP in which ligaments are taut and the position in which most fractures and dislocations occur.
The proximal and distal carpal row articulates with each other and adjacent to form 5 separates joints
1. Radiocarpal joint
Lies between the distal end of the radius and articular disk which is concave and the proximal row of carpals
(proximal pole of the scaphoids, the lunate, and triquetrum) which is convex.
2. The Midcarpal joint
More complex the
1. Distal pole of the scaphoid, the trapezium, and the trapezoid act as a unit.
2. The proximal pole of the scaphoid the lunate and the capitate form a “ball and socket” configuration.
3. The hamate articulates with the distal ulnar margin of the lunate in most adults
4. The triquetrohamate association is especially complex, with articular surfaces being both concave and
convex and therefore somewhat spiral shaped.
3. The first CMC
Saddle joint: Trapezium and first metacarpal. Loose capsular ligaments permit 55° thumb extension, 50° of
abduction and 17° of axial rotation.
4. The common (2-5) CMC’s Distal carpal row to base of metacarlpal 2-5: they permit gliding motion that is minimal, increases
progressively toward the base of the 5th. Movement here contributes to the mobility of the distal transverse
arch of the palm.
5. Pisotriquetral
Allows the pisiform to glide on the triquetrum and leverage forces. The sesamoid nature of the pisiform
allows a greater moment arm for the joint thus facilitating greater torque across the wrist from the FCU
Wrist flexion
From 65°-80°
Wrist extension
Wrist Radial Deviation
Wrist Ulnar deviation
From 68°-80°
From 10°-20°
From 20°-35°
-Motion required for functional task is generally believed to be 40°
each of flexion and extension and 40°of combined UD and RD.
-It is generally agreed that the axis of rotation of the wrist through the
head of the capitate = flexion/extension and Radial/ Ulnar movement
Description
Intracapsular ligaments
The following planes:
Classifications
Stabilize the carpus in the presence of the The names reflect the bones and they span:
Collagen fibers bundles:
following forces:
1. Proximally to distally
 Tightly packed
1. Static
2. Laterally to medially
 More important mechanically
2. Dynamic
Mechanoreceptors:
 Less structural
 More Proprioceptive in nature
Intra-Articular ligaments
Extracapsular ligaments
 3-D between bones or Interosseous ligaments
 Transverse carpal carpal ligament and
Scapholunate: (SL) one of the most common injured
 The two distal connections of the pisiform to the hamate and the
(Associated with a numerous of clinical disorders)
base of the 5th metacarpal
Lunotriquetral: (LT) : more kinematic congruent the
connecting fibers are taut with all motions.
Dorsal ligaments:
 Weaker protect against
hyperflexion.
 They are a few in numbers
 Functionally and
Structurally REINFORCED
by the floor and septi of the
fibrous tunnels through
which the EXTENSORS
tendons pass



Palmar ligaments:
Thick and protect against hyperextension
Extrinsic and Intrinsic form inverted shapes that reinforce the wrist
o Capitate the Apex distally
 Distally of the Ulno-capitate and Radio-Scaphoid= Referred as the
ARCUATE LIGAMENT
o Lunate is the Apex proximally
 Ulnocarpal ligament (Ulno-lunate and Ulno-triquetral) and the short and
long Radio-Lunate legaments.
o The space between this two complexes = The Space of POIRIER
 Inherently weak and filled with synovium overlaying the capitolunate joint.
Extrinsic
Intrinsic








Connect the radius and ulna to the carpals
Connect carpals to the metacarpals
Stiffer and have lower yield strength.
May be prone to RUPTURE more in MID-substance
Connect adjacent carpal bones
Have a larger areas of insertion into cartilages
Have many less elastic fibers
May be fail more frequently by avulsion.
MP
Joints

Link the metacarpals and to proximal phalanges.
Strong proper collateral
ligaments:
Accessory collateral
ligaments:
Dorsal hood of the
extensors
Run oblique from the dorsal aspect of the metacarpals to the volar phalanges.
 Reinforce the articular capsule of the MP joints
This ligament become
To prevent ligament contractures during immobilization following
taut with flexion
injury or surgery, a practitioner shoulder splint the MP in as much
flexion as possible (eg, 70°-90°) in not contraindicated by other factors
Lie just volar to the proper collateral ligaments and insert on the volar plates as does the fibrous
digital sheath (pulley) that Holds the flexor tendon.
Reinforce the dorsal capsule of the MP Joint
It has a flat layer of fibers that are perpendicular and oblique to the long axis of the digits
 Sweep around from one edge of the volar plate to the other and are called
o Sagittal bands
 They are key centralizing the extensor tendon over the metacarpal
head.
Volar plate
 Thick fribrocartilaginous volar plates
 Are intimate parts of the joints capsule volar surface
 Attach firmly to the phalangeal bases
 Attach loosely to the metacarpal heads where they pleat during flexion
 Protect the joint from excessive hyperextension.
 Their superficial surfaces provide troughs that connect with fibrous tendon sheaths
(pulleys) that channel the flexor tendon.
Superficial and Deep Transverse metacarpal ligaments Tether the individuals metacarpal heads to one another
Differs from the other MP joints :



Uniaxial compared to biaxial
Hood mechanics is similar but the
Volar plate has 2 sesamoid bones
o Bones in it form a channel for the
 Flexor Pollicis Longs (FPL)
o This volar plate and sesamoid bone complex is also the site of partial insertion
 Ulnar side
 Adductor Pollicis
 Ulnar side is thicker and stronger when compared to the radial side
 Radial side
 Flexor Pollicis Brevis
 Dorsally:
 Forms an aponeursis and blends with:
o Extensor Pollicis Brevis
o Extensor Pollicis Longus

ROM
o 50° flexion
Limits extension to 0°
Thumb MP joints:
 Up to 90° Flexion
 Up to 25° Hyperextension
 Up to 20° of Abduction and Adduction
 Accessory movements include:
o Traction
o Rotation
o Gliding
Hinge joints between proximal and
middle phalanges
Thumb IP Joint
Proper Collateral
ligaments
Accessory
ligaments
PIP Joint capsule
Bony congruency provided:
 By sagittal oriented groove in the head of the proximal phalanx
 And by the corresponding ridge in the base of the adjacent phalanx creates inherent stability.
Permits up to 90° of flexion
And limits to 50° of extension.
They reinforce articular capsules
Contribute to medial and lateral
stability
PIP 2-5’s
Permits 110° of flexion
Accessory movement:
1. Traction; 2. Rotation; 3. Gliding
And limits to 0° of extension
Because the collateral ligaments are taut over the bony crest in extension and
phalangeal heads are not cam shaped like the metacarpals head the PIP joints
shoulder be immobilized near FULL Extension to prevent contracture of the
collateral ligaments and volar plates
They suspend the volar plates and adjacent flexor
As well as serve to improve the tendon efficiency by maintaining
tendon mechanisms in a SLING-Like fashion Pulleys them close to the joint axis.
Dorsal
Volar
Reinforced by the central slip of the extensor
Reinforced by the volarly by the PIP volar plate is the thickest
tendon (Which insert onto the dorsal surface of the distally and thins centrally and proximally. It attaches to the
middle phalanx)
proximal phalanx through two fibrous extensions (Check the
Rein Ligaments)
Pathological fibrosis can thicken these attachments so that they
become contracted and therefore limits PIP joint extension.
Description:
 24 Extrinsic
 19 Intrinsic
1. Hand position
Extrinsic
Torque:



These muscles act on bony and ligament attachments to produce wrist and hand motion.
Muscle units in the wrist and hand do not operate alone but cooperatively contribute to:
The function of the hand is to:
o To produce torque
o To produce tendon excursion
2. Stability
3. Motion by contraction or relaxation of agonist and antagonist.
Cross multiple joints
Intrinsic:
They balance opposite forces
flexor and extensors extrinsics.
The joints relative position alter
Combine with extrinsic to
muscle functions (length-tension
support the segments and
relationships)
therefore controlling the rays
 Is the product of tension (force)
 And the moment arm (The perpendicular distance between the joint axis and the tendon as it
crosses the joint)
o Increasing the moment arm improves the tendon’s mechanical advantage, making it easier
to generate torque
o A larger moment arm requires the tendon to glide more to produce the same amount of
joint motion
A gain in torque at the expense of the increasing the moment arm decreases the ROM
The amount of tendon excursion determines the ROM through which a joint moves.
Excursion: Is relative to muscle fiber length (longer fibers can produce more excursion than shorter fibers)
 A tendon connective tissue attachments, such as retinacula and pulleys, enhance excursion by preventing bowstringing across joints
o Thus limiting the limiting the distance the tendon must travel to execute it action.
1. Extensor retinaculum binds the 9 extensors
2. Vertical fibrous septa divide the retinaculum into 6 compartments
The First Dorsal
Holds:
It is the site of the De Quervain syndrome
Compartment
1. Abductor Pollicis Longus (APL)
2. Extensor Pollicis Brevis (EPB)
The Second Compartment
Contains:
ECRL & ECRB insert on the base of the second and third
1. Extensor Carpi Radialis Longus (ECRL)
metacarpal= extension of wrist *
2. Extensor Carpi Radialis Brevis (ECRB)
The Third Compartment
Holds:
Intersection syndrome can occur between the tendons
1. Extensor Pollicis Longus (EPL)
in the first and second compartment.
The fourth Compartment
Contains:
1. Extensor Digitorum (ED)
2. Extensor Indicis (EI)
The fifth Compartment
Is occupied by:
1. Extensor digiti minimi (EDM)
The sixth Compartment
Is filled by:
Subluxation of the ECU tendon can occur if the deep retinaculum
1. Extensor Carpi Ulnaris (ECU)
(sub-sheath) becomes unstable and dislocates due to repetitive
stress
ECU inserts on the into the base of the fifth metacarpal= extension
of the wrist *
ECRL+ ECRB + ECU= work together to extend the wrist
The juncturae tendinum join
the ED tendon to another = Limiting independent movement, particularly of the ring finger.
Sagittal bands:
Is the main connection of the extensor tendon to the proximal phalanges
 These bands of fibrous tissue form slings around the proximal phalanges and attach to the volar
plate
o They allow ED tendons to extend the MP joints by lifting the proximal phalanges
o They also prevent tendon bowstringing and
o They also stabilize the ED over the midline of the MP joint extension.
ED+EI +EDM tendons Are the only extensors of the MP Joint Therefore: Tendon lesions and radial nerve loss preclude MP
joint extension.
Dorsal Hood
As each ED tendon continues distally, it is joined by fiber from the intrinsic muscles forming a dorsal
hood.
Central Slip
Some fibers continue as central slip that attaches to the dorsal base of the middle phalanx and extend
the PIP joint
Lateral bands
Other fibers contribute to the lateral bands that lie dorsally on either side of the middle phalanx.
 The lateral bands join distally, forming the terminal tendon.
Terminal tendon
Inserts on the dorsal base of the distal phalanx and extend the DIP joint.
PIP & DIP Transverse
 Originates from the PIP joint volar plate and flexor tendon sheaths, encircling the joints as they
Retinacular
run dorsally to attach the lateral bands
Ligaments
o They prevent the lateral bands from bowstringing dorsally to the PIP joint.
o Laxity in pathological condition such as RA permits the lateral bands to slip dorsally,
placing and excessive extensor force on the joint
 This contributes to a SWAN-NECK deformity (PIP hyper-extension with DIP joint
flexion)
Oblique retinacular
 Also originate from the PIP joint volar plate and flexor tendon sheaths, running obliquely to
ligament
insert on the terminal extensor tendon
 Lies volar to the PIP joint & dorsal to the DIP joint
 The oblique ligament passively coordinates PIP and DIP joint motion
 Most hand activities requires both joints to extend together or flex together
 EXTENSION OF THE PIP joint tightens the oblique retinacular ligament that exert and extension
force on the DIP JOINT.
 FLEXION OF THE PIP joint relaxes the oblique retinacular ligament that allows the DIP to flex
farther.
 Twelve flexor muscles cross the volar wrist.
FCR
Inserting on the bases of the second and third metacarpals
Palmaris Longus
Attaching the palmar aponeurosis
FCU
Inserting on the pisiform (sesamoid bone) then continuing on as the pisohamate and pisometacarpal ligament
FPL
Pass deep to the flexor
After crossing the carpal tunnel the tendon travels distally to insert on the base of
retinaculum
the distal phalanx of the thumb.
FDS
With its 4 tendons pass deep to Insert on the bases of middle phlanages. Is capable of independent movement.
the flexor retinaculum
The primary function:
 PIP flexion
 Assist with MP flexion
FDP
With its 4 tendons pass deep to Insert on the bases of distal phalange
the flexor retinaculum
Divided at the forearm into two bundles the Radial and Ulnar:
Radial:
 This one continues as the FDP tendon to the index finger
Ulnar:
 This further divides in the carpal tunnel into tendons to the
o Long
o Ring
o And Small
 Which do not have independent movement. Producing a quadriga effect
o In which the distal tension on the one tendon limits active motion of
the other tendons.
Sole flexor DIP assist in PIP and MP flexion. FDP muscle is 50% stronger than FDS
and perform most unloaded flexion movement.
Restrain the flexor tendons to the metacarpals and phalanges and contribute to fibro-osseous tunnels through which the tendon travels.
By preventing bowstringing way from the phalanges
 These restrain improve the tendon’s efficiency and
 Decrease the excursion they need to execute finger flexion.
A1= Arises from the MP joint and volar plate
C1= Originates near the head of the proximal phalanx
A2= Arise from the proximal phalanx
C2= Originate near the base of the middle phalanx
A3= Arises from the PIP joint volar plate
C3= Originate near the head of the middle phalanx
A4= Arises from the middle phalanx
A5= Arises from the DIP joint volar plate
The pulley system of the thumb includes the A1 arising from the MP joint volar plate
 A2 arising from the oblique pulley from the proximal phalanx.
The intrinsic muscles play a vital role in balancing, and modulating extrinsic flexor and extensor muscles forces
The lumbricals are known as the workhorses of the extensor mechanism,
They contribute significantly to IP Joint extension
As well as MP flexion
- They achieved this by contracting and pulling the dorsal
hood proximally
- They have the unique ability to minimize force
antatonistic to their action because their contraction
- Also pulls the FDP tendon (their antagonist) distally,
lessening its resistance
Another example of the lumbrical muscles interconnections is a phenomenon known as PARADOXICAL EXTENSION
This occurs when the FDP is detached distally/ or is excessively  long (Attenuated tendon graft) therefore it can not flex the DIP rather the FDP contraction is
misdirected through the lumbrical muscles to the dorsal hood, resulting in DIP joint extension instead of flexion.
Dorsal
Volar
 4 Dorsal
 3 volar
 In general they abduct the digits away from the
 In general they adduct the digits towards the middle
middle finger
finger
The intrinsic position volar to the MP joint axes the and dorsal to the IP joint axes produces joint flexion and IP
extension
They are similar to the finger intrinsic muscles and contribute to movement and dynamic stabilization of the thumb
AP
APB
OP
FPB
Is the strongest and it has two heads
 It arises from the palmar surface of the second and third metacarpal, the capitate, the palmar ligament
and the sheath of the FCR
 Inserts into the medial sesamoid bone at the base of the proximal phalanx and the dorsal hood of the
thumb.
Adducts the thumb and reinforce the thumb Ulnar Collateral Ligament
 Arises from the flexor retinaculum, scaphoid, trapezium and APL tendons
 Inserts into the lateral base of the proximal phalanx and dorsal hood of the thumb.
It abducts the thumb both the AP and APB muscles assist in IP joint extension in addiction to adduction and
abduction respectively
It rotates the thumb into pronation and flexes and abducts the firs CMC joint, thus producing opposition
It has two origins similar to (APB)
 Both head inserts on the base of thumb proximal phalanx,
 Lateral sesmoid bone, and dorsal hood.
It flexes the MP joint and extends the IP joint
ADM
FDM
ODM
MUSCLES HAVE ORIGIN on the
flexor retinaculum= hamate
psiform.
Inserts are on the base of small finger
proximal phlalnx
Insertion on the fifth metacarpal shaft
Their functions mirror the
functions of the respective thenar
muscles.
Neurovascular structures
Median Nerve
Pronator teres
Flexor digitorium superficialis
FDP
Pronator quadratus
Crosses the wrist deep to the
Flexor retinaculum 9 flexors
tendons and sometimes is due
to compression
OP
Supplies the superficial head of
FPB
1,2 lumbricals
It gives two motor branches
FCU
Terminal sensory supplies the
lateral, palmar and volar aspect of
3 ½ digits extending dorsally
posteriorly over the fingertips to
the DIP
FDP (rign and small)
Palmar cutaneous
Sensory to skin over the medial
wrist and hypothenar eminence
Enters the ulnar tunnel (radial to
the pisiform and ulnar to the
hook of the hamate) divides
Deep motor branch
Dorsal Cutaneous branch
The ulnar nerve crosses the
wrist superficial to the flexor
retinaculum
Skin over the medial part of the
palm and the medial 1 ½ digits
All dorsal interossei
Anconeous
PIN
ED
FCR
After passing the pronator Teres
gives off Anterior Interosseous N.
4 cm proximal to wrist Palmar
Cutaneous branch
Palmaris longus
FPL
Supplies the skin over the
central part of the volar anterior
wrist
APB
ULNAR
NERVE
Superficial branch
Palmar and dorsal cutaneous
branches approximately 5cm to
10 cm proximal to the wrist
Sensory to the skin over dorsal
aspect of the medial 1 ½ digits
Supplies the palamris brevis
Hypothenar
3rd & 4th lumbrical
Deep head of the FPB
AP
Radial nerve
Brachioradialis,
Just proximal to supinator
ECU
ECRL
ECRB
EDM
Divides into sensory and motor
Supinator
APL
EPL
EI
CONNECTIVE TISSUE DISORDERS
TENDONITIS
TENOSYNOVITIS
STENOSING TENOSYNOVITIS
Aseptic inflammation of tendons
Occurs when inflammation involves the synovial-lined tendon sheat
Is a condition in which irritated tendon sheath becomes thickened and
fibroses
* Repetitive motions is often the cause of tendonitis which can affect any of the extrinsic tendons
Tendons on the 1st, 2nd, 6th compartment and the digital flexors tendons beneath the A! pulley are the most commons involved.
Thickening of the tendon sheaths
Degeneration APL, EPB (1st Extensor
compartment)
Swelling in this compartment encloses the
MOI: scissors, opening jars, lifting a toddler
Clinical features: pain, swelling radial styloid,
space restrict tendon gliding.
discomfort with thumb movements
Testing:
Conservative treatment:
Modalities:
Goal: decreased pain, increased smoother
 Finkestein test +, occurs when patient
 Cold to reduce inflammation
excursion
of
the
tendons
through
the
flexion thumb and then ulnarly deviates
 Use of forearm-based thumb spica splint
compartment.
the wrist.
( IP joint free)
 Resistive thumb abduction and
 Ultrasound
extension also provoke pain
 NSAIDS
 Ergonomics
Therex:
Preventive measurement:
When indicated (symptoms may subside)
 Cortisol injection to 1st compartment
 Heat
o Complication if injections fails
 Depigmentation
 AROM pain free
 Subcutaneous atrophy
 Endurance activities
 Fat necrosis
Is a stenosing tenosynovitisof the digital
Area where the flexors are subject to significant  Inflammation,
flexor tendon sheath in the area of the A1
tension and friction
 Fibrosis and
pulleys
 Thickening of the tendon sheath
Clinical features: Produce snapping or
MOI
Pathophysiology:
triggering when the patient attempts to
1. Ideopatically produced
The tendon sheath extends more proximally
extend the involved digit from fully flexed
2. Or secondary to repetitive gripping or
than the pulleys system and a palpable, tender
position
grasping an object with a sharp edge
nodule may develop at the proximal edge of the
sheath
De Quervain disease
Trigger Finger or
thumb
Symptoms:
 Intermittent finger locking during active
flexion
 PROM is normal
Hand based or finger orthotic device that
position the MP joint at 0° and allows full
PIP joint movement
Tx post release:
 Active finger therex
 Progress to tendon gliding
 Light resistive exercise by 2 weeks
Commont locations:
 Dorsal SL (Scapo-Lunate) Interosseous
ligament (60%)
 Volar Radiocarpal ligament
 The FCR sheath
 Extrinsic flexor tendons
Prognosis:
 50% will disappear spontaneously.
Dupuytren Disease:
Genetically induced 8:1 more in men’s than
womens
Tx:
PT not effective before sx
PT after surgery:
 Dressing removal 1st week
 Scar massage
 Silicone gel pad if scarring is prominent
Week 3:
Stretching and resistive exercises
Often the impairment appears to present at the
PIP joint because the nodule release under the
A1 pulley as the PIP joint extend and becomes
painful
Tx: Injection of Cortisol to the tendon sheath if
symptoms do not improve.
Ganglions
Non Operative tx:
 Avoid repetitive gripping,
 NSAIDS
 Rest
If symptoms persist:
May require a surgical release of the A1 pulley.
(97% resolution)
Is a cyst mucin filled mass that protrudes from
the synovial membrane of a tendon sheath or
joint capsule.
Onset:
 Usually insidious
 10%- 15 % antecedent trauma such as
repetitive motions
Clinical presentation:
 May present with a visible palpable soft
mass that may be painful and interfere with
motion.
Conservative tx:
 Local compression
 Resting wrist orthotic device
 Aspiration
 NSAIDS
 Steroid injection
Is a progressive fibrosis of the palmar
aponeurosis, natatory ligaments (within the
web spaces), and digital fascia
Sx:
Fasciotomy, dermafasciectomy
May be a candidate for surgery:
Post sx rehab:
 AROM
 Resistive exercise
As symptoms permit
Evaluate:
 Wound edema
 Sensation
 ROM
If patient cannot achieve full extension:
 Splinting with a static progressive
dorsal, hand based orthotic that is
adjusted to increased extension.
Clinical presentation:
 Flexion contracture of MP and PIP (ring and
small finger and thumb)
 Web space
 Contractures are usually bilateral
Goals:
Gain extension caution when stretching the
incision (no tension on the wound better
healing)
Recent studies: Collagenase clostridium
histolyticum injection is a safe and efficacious
treatment for contractures.
20°-100° PIP and 20°-80° at the MP joint
reaseach does not includes thumbs.
After injection collagenase injection:
 Patient wears a night extension splint
for 4 months and performs finger
ROM exercises
Old school belief was that: in-growth of adhesions was necessary for revascularization and supplying fibroblast required for collagen
synthesis.
Practitioner routinely immobilized the hand to allow car adhesion
Investigator found that tendons have intrinsic ability to synthesize
and preserve the delicate capillary and fibrous meshwork essential
new collagen fibrils, they found that tendons rely not only on
to extrinsic healing
vascular perfusion from and extrinsic source for healing, but that
they also heal intrinsically through nutrition they derive from
synovial fluids diffusion.
Motion not load is the critical factor when optimizing early tendon
Research found than controlled stress applied early in the healing
gliding.
process enhances the strength of the repair, minimizes repair site
deformation and stimulates wound maturation and scar remodeling.
FLEXOR TENDONS REPEARS
Laceration is primary Avulsion
MOI
May by complete
Crush
Disease process can also disrupt
tendon continuity.
Or incomplete
Ideally surgeons prefer to treat complete flexor tendon laceration immediately within 12 hours of occurrence.
Treatment of partial laceration (<50%) includes:
Protection in a dorsal splint for 6 weeks.
 Surgical debridement
Triggering
Entrapment
And rupture
If left untreated:
The strength of the flexor repair is roughly proportional to the number of suture strands crossing the repair
site
Research showed that 4-strand core suture combined with peripheral epitendinous suture safely permits light
composite grip during the entire healing period.
No clear benefit was showed to sheath repair. It is essential to preserve A2 and A4 to prevent tendon
bowstringing sway from the proximal and middle phalax
Surgical management by zone
Injury Zone 1
Injuries to Zone II
Injury to Zone III
Injury to Zone IV
Injury to Zone V
Involved the isolated FDP
The surgeon removes the pullout
suture after 4 to 6 weeks.
Sx:
 May involved direct suture to its distal stump
 Or by insertion into the distal phalanx
End to end repair is technically difficult because of the limited space within A5
pulley
Usually involves both FDS and FDP tendons
They required special consideration to
 Intimately contained within a tough immobile fibro-osseous sheath.
maintain gliding and prevent adhesions
formation between the two tendons.
Sx:
Usually repair both tendons primarily with judicious use of atraumatic
handling principles.
Injuries in the palm may be accompanied by damage to the:
* Suturing lumbricals muscles bellies may
 Distal nerves
increase tension and result in lumbrical plus
 Vascular structures
deformities; therefore, surgeons therefore
 Or lumbricals
elect not to repair the muscle.
Sx:
Primary repair of :
 Tendons
 And nerves produces de best results
Tendon injuries within the carpal tunnel may also involve the median
Results of repair are usually favorable
nerve
If release of flexor retinaculum is necessary, the wrist should be
splinted in neutral, not flexion, to prevent the tendons from
bowstringing away from the carpal canal
Injuries may occur with to neurovascular structures at this level the FDP Primary repairs have good prognosis
has not divided completely
Zone T1(thumb) and TII injuries are more likely to result in significant
proximal FPL tendon retraction . This necessitates a separate proximal
incision at the wrist to retrieve the tendon.
Postoperative Management
The goal
 Protect the healing tendon from:
Numerous approaches:
o Excessive forces (preventing gapping or rupture)
 Initial immobilization
 Restore tensile strength
o Young patients (non complaint)
 Promote gliding
o Cognitive impaired
 Prevent adhesion that limits tendon excursion.
o Multiple injures
Different protocols for different patients:
 Early passive mobilization
 For all protocols therapist should emphasize:
 Early active mobilization
o Tendon excursion rather than
 Increased force through the
musculotendinous unit.
Not mention on this monograph tendon repair based every zone
Most tendon protocols were developed for repairs in Zone II because
the rehabilitation is most difficult.
Immobilization
Early stage (day 3 to week 3-4)
 Forearm-based dorsal block splint
The patient performed PROM of uninvolved joint
 With the wrist 10° to 30° of flexion,
with HEP and sees the PT 1-2x per week for wound
 The MP joints in 40° to 60° of flexion
management.
 The IP joints extended
Intermediate stage begins ( 3-4 The patient progress to a
Begins:
weeks)
neutral wrist splint
 Passive finger flexion followed by
 Active extension, and
 Begins active differential tendon gliding exercises while the wrist is
extended to 10° to employ synergistic wrist motion (tenodesis)
* To progress asses movement after 4 to 4 days and active composite
flexion is > 50° the patient is assumed to have considerable adhesion
formation and is ready to progress to the next phase
Late Phase immobilization
The splint is D/C
This is dependent on tendon gliding. Therapist begins:
protocol (Starting @ weeks 4)
Gentle isolated blocking exercises.
If muscle-tendon unit is short then we have a problem the patient
may wear a splint with fingers and wrist in extension.
Early passive mobilization
This protocols were developed after it was noted that scar adhesions predominated after tendon immobilization.
Kleinert
Durant and Houser
Rubber band traction splint
Finger strapped into extension in a dorsal block splint when not performing the
exercises
Those protocols were used initially that now include variations by a wide range of surgeons and therapist.
Early stage 0- 3½ weeks after surgery
The basic rationale is to put slack on the
Nutrition to the healing tendons is
repair tendon (s) using a:
encouraged by:
 Forearm block splint with the wrist in  Passively flexing the finger (s)
HEP: Passive PIP, DIP the a composite
slight flexion
 And then actively extending it (them)
flexion with MP joint in 
 The MP in a relaxed position of flexion * All this on the safety of dorsal block splint
Intermediate stage 3½ - 8 weeks after
Replacing the dorsal block splint with a
Another way of achieving this is by removing
surgery
wrist cuff and rubber band for tension
the dorsal block from the splint.
such that finger extension and wrist
extension cannot be done simultaneously.
The late stage (8 weeks and on) after surgery This stage focus on:
Care must be taken to prevent PIP joint
 Improving tendon gliding starting
contracture
 Start resistive exercises
Early active mobilization
Benefits:
Surgeons recommend active mobilization after 3-5 days post surgery.
However all programs limit active flexion for the first 3-5 weeks. What is done
on the initial stages is allow tendon gliding thus granting suffient glide under
the pulleys with a milking effect that provides nutrition to the tendon.
Candidates:
 Patient that able to handle parameter of this protocol
 Repair should be at least 4 strands of suture in the core
 In addition to a well-designed circumferential suture.
The Belfast and Sheffield protocol
Early active ROM 0- 3½
Protocol:
X2 reps of full passive finger flexion
Active extension with dorsal block splint
Requires a dorsal block splint with the wrist
at 20° of flexion and the MP joint at 80°-90°,
allowing full IP joint extension.
After two day of rest Post OP. Therapist
instruct patient begin early phase exercises
ever 4 hours to allow post-surgical edema to
subside.
Active flexion (patient should make a target with contralateral 4 finger across his palm
Small finger on the palm Then actively flex to try to touch the index finger
Over 3 weeks the target for active flexion decreased to 3 finger, then 2, and so until able to
touch the palm
Intermediate stage 3 ½ - 8 weeks
Discontinuing the splint if the patient has
restricted tendon glide.
 If not the splint can be worn one to two
weeks longer
Late stage 8-12 weeks
Progression is based on the response to the
amount of lag that is present
Strickland and Cannon protocol
Early stage 2
Most of the time:
days to 4 weeks.  Fore-arm based dorsal protective splint with the
(uses 2
wrist at 20° flexion
differential
 MP joint 50° flexion
splints)
Patient uses an exercise splint:
 Hinged component at the wrist allows full flexion
block extension at 30°
 It permits full IP joint extension
 Limits MP joint extension to 60°
Intermeidate
stage 4- 7-8
weeks
D/c splint.
Instruct the patient to use the dorsal block splint for
protection except for exercising
Late stage 8+
weeks
D/C dorsal block splint. Adds resistive exercises to the
program
If residual flexion contracture exists the
therapist fabricates a finger-based
orthotic device to promote extension.
 Passive PIP extension begins in a
protected position (MP held in flexion)
 Continue with active flexion and
extension exercises
Full flexion is expected at 12 weeks.
Exercises every hour:
 Passive hold the MP and PIP joints in flexion
 Then passively flex the DIP joint.
 Then passively hold the MP and DIP joint in flexion and
 Passively flexion the PIP joint.
 Follow with place and hold exercises performed in the
splint
 The patient passively flex the fingers
 Actively extends the wrist
 And then actively maintains finger flexion for 5 seconds.
The patient perform synergic wrist movement:
 Active finger flexion
 5-6 weeks PT adds blocking and hook fists for
tendon gliding
Special care given to the small fingers due to the propensity
for higher rates of rupture.
Evans and Thompson:
Have concluded that forces increase dramatically at the end range of flexion (full fist) and when digit flexion is combined with wrist flexion.
 They also question whether patient seen only weekly in therapy can reliably perform protocols at home
To help guide decision making, the pyramid progressive force application developed by Groth is helpful.
If a digital nerve has been repair:
Caution no to put tension on it in the splint
Flexor Pollicis
longus repairs
Using a soft strap to keep the IP joints extended at night in the splint will
help prevent PIP joint contracture
Early active motion and modified dynamic flexion protocols both provide adequate postoperative
mobilization
Extensor Tendons
Injuries that have increased scar tissue can disrupt the healing such as:
Dorsal hood,
periosteoum
Or the bone itself
50% less stronger than flexor due to thinner substance
Disruption at Zone 1 MOI: Most forceful extension of DIP joint such as being hit with a ball
 Occurs at <45° of DIP flexion = Ruptures the terminal tendon
 Occurs at 45° or greater = Produces a bony avulsion .
Some avulsion requires sx:
1. Presence of avulsion
2. Significant fragment displacement
3. Volar DIP joint subluxation
Mallet finger
1. Point of tenderness
2. Swelling over dorsal joint
3. Lack of active extension
Swan neck deformity
1. Occur on chronic
2. The entire extensor mechanisms 3. (Hyper extension at the PIP joint and flexion at
injuries
may retract proximally
the DIP joint.
Closed Injuries without
Inmobilization in slight hyperextension (no skin
Either custom splint or pre-fabricated .
fractures
blanching) 6-8 weeks
 Care to maintain passive extension during splint
removal.
After 8 weeks weans off splint (uses the splint for
heavy activity)