Extensor Tendon Repair Flashcards
The mainstay of rehabilitation at the digital level (zones
1-4) remains static splinting
T
early motion protocols have shown promising results in more proximal injuries (zones 5-8
T
extensors exhibit minimal excursion
T
Due to the superficial position of extensor tendons, they are vulnerable to injury and exposure
T
The
stronger opposing action of the flexor system makes early rehabilitation even more problematic
T
The deffiuclities with extensors tendons
the proximity of the tendons to bone, the high incidence of associated periosteal stripping and capsular injuries, and
the limited excursion of the extensors makes repair prone to adherence. Furthermore, the mechanical strength of the repair and status
of local soft and hard tissues may not allow early mobilization. The
stronger opposing action of the flexor system makes early rehabilitation even more problematic
BR is not a wrist or
digital extensor-it flexes the elbow and it supply by radial nerve
T
BR and ECRL are innervated above the elbow,
whereas ECRB is innervated below the elbow
T
a radial nerve
laceration at or below the elbow is likely to maintain wrist extensor
function
T
the last muscle to receive innervation
from the PIN
the extensor
indicis proprius (EIP)
the last to recover after a nerve injury
the extensor
indicis proprius (EIP)
EIP . EDM they typically lie ulnar to the EDC
at the level of the MP joints
T
The attachments of the extrinsic finger extensors onto the sagittal band make them effective extensors of the MCP
T
EPL forms the dorsal boundary of the anatomic snuffbox
T
the interossei
are the primary flexors of the finger MP joints
T
the interossei course dorsal to
the deep transverse metacarpal ligament
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here are no juncturae that link to the thumb extensors.
T
The lumbrical muscles lie on the ulnar side of the
respective flexor tendon
T
They course volar to the deep transverse
metacarpal ligament before attaching to the radial lateral band of the
respective finger
T
The intrinsic extensor tendons lie volar to the axis of rotation of
the MP joint and dorsal to the axis of rotation of the IP joints
T
Intrinsic muscle action
is also responsible for volumetric grip that starts with coordinated
MP joint flexion and simultaneous IP joint extension
t
Patients with
combined lower median and ulnar nerve palsy are unable to perform volumetric grip, and instead initiate finger flexion at the IP
T
The intrinsic muscles of the thumb are mainly involved in rotational motion.
T
Why patient still be able to extend the thump in case of EPL in jury ?
the adductor pollicis (ulnar) and the
abductor pollicis brevis (radial) insert onto the EPL tendon at the
MP joint level, which along with the EPB, gives them the ability to
extend the IP joint of the thumb at least to neutral
The lateral slips pass on either side ofthe PIP joint and merge with
the lateral bands forming the conjoined lateral bands
t
The lateral slips pass on either side ofthe PIP joint and merge with
the lateral bands forming the conjoined lateral bands
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The oblique retinacular ligament (ORL, of
Landsmeer) arises from the lateral aspect of the flexor tendon sheath
at the neck of the proximal phalanx (A2 pulley) and passes volar to
the axis ofrotation ofthe PIP joint, inserting onto the extensor mechanism along the middle phalanx
t
What is the medaiter of MCP extension ?
Historically, it was thought to be mediated by the sagittal bands
recent evidence suggests that the extensor continuation to the extensor hood and middle phalanx is the major mediator
of MP extension
Digital extensor tendon excursion is much wider at the forearm
and wrist level than the digit
T
The excursion of a common extensor
proximal to the wrist is approximately 5 cm
T
Every millimeter of extensor tendon lengthening over the proximal phalanx leads to 12° of extension deficit at the PIP joint.
T
the DIP joint where each millimeter of
relative terminal tendon lengthening results in 25° of extension lag.
T
zone 1 and 2 injuries requires static splinting for
6 weeks followed by night splinting and range of motion exercises
T
Early controlled motion
using dynamic splinting has shown promising results for zone 4 to 7
T
dynamic splinting suited for patients who are compliant
and have associated bony and soft tissue injuries
T
The idea is that
early controlled gliding of the tendon will break up impending adhesions while minimizing risk of rupture.
T
Dynamic splinting protocols
are just as effective as early active motion protocols with less risk of
tendon rupture
T
More proximal injuries in zones 8 and 9 carry the
least risk of adhesions and can be treated with static splinting for 3
to 4 weeks.
T
The EIP is absent in 4% ofindividuals
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The extensor digitorum brevis manus muscle is an anomalous dorsal
muscle, present in 3% ofhands, which arises distally on the wrist between
the index and middle finger metacarpals
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The zone one extensors tendons injury is more commonly closed rupture
T
The terminal tendon usually inserts
onto a thin area on the dorsal/proximal aspect of the distal phalanx. This area corresponds lo the dorsal ledge of the epiphysis prior to
skeletal maturity
T
swan-neck deformity can developed acutley at the time of mallet finger develpment
T in patients with
congenital or traumatic PIP volar plate laxity
Elderly patients with
osteoarthritis can present with a mallet deformity that is atraumatic
T
Injuries
presenting within 4 weeks of trauma are considered acute; after
4 weeks, they are chronic
T
If left untreated, hyperextension of the PIP
joint can develop because of proximal and dorsal migration of the
lateral bands,17 creating the swan-neck deformity
T
Type of mallet finger ?
- Closed injuries without subluxation encompass the great majority of mallet injuries (types I and IVb)
- Open injury with laceration to the terminal extensor
- Open injury with loss of skin and/or tendon substance
- IVA Transepiphyseal plate fracture in children (Seymour’s fracture)
IVB Hyperflexion injury with 20%-50% fracture of articular surface
IVC Hyperextension injury with >50% fracture of articular surface with
early or late volar subluxation of distal phalanx
extensor action on the IP joints
is mediated by the extrinsic system when the MP joint is flexed and by the
intrinsic system when the MP joint is extended.
T
Treatment of type 1 mallet
Best treated with continuous splinting of the DIP joint in extension for 6 weeks, followed by 2 weeks of night splinting
Residual extensor lag of 5° to 10° is common
T
Type mallet finger surgery?
- Technique ofskin imbrication! tenodermodesis
- Fowler tenotomy/central slip tenotomy
- Spiral ORL reconstruction
What is Fowler tenotomy ?
The principle underlying this procedure is a release of the central
slip, allowing the now centrally untethered lateral bands to move
proximally and reduce the slack within the extensor system distal to the PIP joint, correcting the extensor lag at the DIP joint.
A boutonniere deformity is prevented by keeping the triangular
ligament intact.
T
Spiral ORL reconstruction:
This procedure links the position of
the PIP joint to that of the DIP joint. Performed with a tendon
graft or a lateral band, it links the terminal tendon or distal
phalanx to the flexor tendon sheath or proximal phalanx, leading
to a dynamic tenodesis
A swan-neck deformity is flexion of the DIP joint with hyperextension of the PIP joint. It occurs after a traumatic (untreated) mallet
finger when the PIP volar plate is lax.
T
For PIP joint laxity, one should attempt conservative treatment with figureof-eight splinting
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volar plate imbrication
or FDS tenodesis may work for pip joint laxity
T
If the primary issue is DIP extension
deficit, then ORL reconstruction or Fowler tenotomy are advocated
T
Joints should be supple before operative correction is attempted
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DIP joint is invariably open and needs to
be washed out in type 2 mallet finger
T
Untreated Seymour fracture can lead to
osteomyelitis.
T
Seymour’s fracture required reduction and antibiotic
coverage.
T
In type IV 2.3 mallet , Operative and conservative methods of treatment are acceptable, even in the presence of volar subluxation of the distal phalanx.
T
Chronic zone 2 injuries can be treated with spiral ORL
reconstruction, as in chronic mallet injuries
T
Zone 2 injury They can involve the two conjoined lateral bands and the triangular ligament that restrains them in the dorsal midline.
T
Both lateral bands are required to achieve the DIP joint extension
F Only one
lateral band is sufficient to achieve full extension of the DIP joint
In the setting of an isolated (closed) central slip injury, PIP
joint extensor lag is usually not present at first
T
The intact lateral
bands and triangular ligament maintain an extension moment on
the PIP joint due to their position dorsal to the PIP joint rotation axis
T
the extension torque gets shifted completely
to the lateral bands, and over several weeks the restraining triangular ligament stretches out, thereby allowing volar translation
and shortening of the lateral bands
T
Type of ORL repair
anchored to the
side of the proximal phalanx (Thompson) or the flexor sheath (Kleinman
and Peterson).
A more reliable test for central slip disruption
Elson test
a boutonniere deformity with closed central slip injury can be treated withsplint
t
The patient performs active DIP flexion and
extension exercises to keep the lateral bands gliding
T
When treated early in a compliant patient, the injury
will usually respond to this conservative approach.
T
a single-core suture is sufficient IN
Open Zone 3 Injury
In addition to the trauma discussed earlier, arthritis, burns, and
synovitis can also cause Boutonniere Deformity and rupture of
the central slip
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Passively correctable deformities should initially be treated with splinting as even late treatment
can allow realignment of the lateral bands
T
Supple joints are a necessity before any surgical interventions for boutonniere
T
fixed chronic cases should be treated with serial
splinting and stretching to maximize joint mobility
T
fixed chronic cases of Boutonniere Deformity surgical options?
Fowler tenotomy transversely divides the extensor mechanism at the junction of the middle and proximal thirds of the middle phalanx while preserving the ORL. This effectively creates a surgical mallet finger
shifts the lateral bands dorsally and sutures them together
over the PIP joint
, Curtis proposed a four-stage process that involves tenolysis, sectioning of the transverse retinacular ligament, distal Fowler tenotomy, and advancement and reinsertion of
the central tendon
most injuries are partial. In zone 4
T The extensor mechanism in this zone is broad and the convexity
of the proximal phalanx shields the lateral bands
Surgical exploration is often necessary to diagnose the degree of injury.
T
The choice of repair
is variable and includes either figure-of-eight absorbable sutures,
or core sutures (2 or 4 of 4-0 or 5-0 nonabsorbable suture) augmented with a cross-stitch on the dorsal surface
T
injuries occur over the MP joint, are almost always open
T
Primary tendon repair will be required after thorough joint
irrigation
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Ulnar sagittal band injuries are particularly
prone to subsequent subluxation
F Radial sagittal band injuries are particularly
prone to subsequent subluxation
Isolated sagittal band injuries are most often closed injuries resulting
from resisted extension of the finger or direct trauma to the dorsum
of the MP joint
T
These are often mistaken for a trigger finger because
of the snapping that occurs when the extensor tendon shifts back and
forth between its natural position and the intermetacarpal groove
T
The
radial sagittal band is more often affected.
T
The affected finger can be extended normally but can’t maintain extension
F the affected finger
cannot be actively extended from a flexed starting position but can be
held in the fully extended position
Closed injuries are treated conservatively by relative motion splinting or casting
T
The ability to hyperextend the MP
joint and/or extend against resistance are often better indicators
of extensor integrity than direct visualization in the ER
T
Even if a single slip of the EDC is
involved, all fingers should be splinted.
T
In injuries
not suitable for early mobilization, figure-of-eight absorbable sutures
may also be utilized in zone 6
T
Partial release of the retinaculum is often necessary to
gain access to the injured tendons IN ZONE 7
T
maintain or repair part (about 50% of its
length) of the retinaculum to prevent subsequent bowstringing
while excising the portion over the repair site to minimize adhesions.
T
The close proximity of
tendons makes problematic adhesions more likely in this zone
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Dynamic splinting or early motion protocols should be considered postoperatively. IN ZON 7
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The extrinsic extensor tendons that have their muscle bellies
end most distally in the forearm
are the EIP (most distal), EPL,
EPB, and APB
The remainder of the extensor musculotendinous
junctions is approximately 4 cm proximal to the wrist
T
Repair of the joint capsule with 6-0 absorbable suture in zone 5
T
adhesions are unlikely to cause substantial tethering
in zone 9
T
repairs should be protected and immobilized for 3 to 4 weeks in zone 9
T
For zone TS injuries of the EPL (wrist), the tendon should
be displaced out of the third compartment and repaired over
the extensor retinaculum.
T
The change
in EPL tendon routing does not alter its mechanics significantly, but does provide a better soft tissue bed to decrease
adhesions
t
spontaneous rupture of the EPL tendon after distal radius
fracture. best treated with EIP tendon transfere
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