HAND AND WRIST TRAUMA

Fractures And Dislocations Of The Hand

These injuries may be classified:
1. Irreducible best treated surgically
2. Reducible-stable best managed with immobilization.
3. Reducible-unstable best treated surgically
When possible, treatment should allow for early functional rehabilitation and should
avoid periods of lengthy immobilization.
Phalangeal Fractures
Distal phalanx fractures are common, are frequently associated with a nail bed injury, and
can remain painful or sensitive long after fracture healing has occurred.
Most of these fractures can be treated with splinting or compressive wrapping.
Phalangeal Fractures
The treatment of extra-articular fractures of the proximal and middle phalanges is
predicated:
1. restoring of bony anatomy,
2. maintaining reduction until bony union,
3. achieving functional rehabilitation.
Fracture stability depends more on the injury mechanism than on the fracture pattern.
Traction splinting is an effective means of maintaining fracture reduction while allowing
for early motion
Phalangeal Fractures
The surgical treatment of extra-articular fractures of the proximal and middle phalanges
must take into account the overlying soft tissues.
Failure to do so may result in injury to the flexor or extensor apparatus and a stiff,
dysfunctional finger.
Distal Interphalangeal Joint Injuries
There is no consensus on the treatment of intraarticular injuries of the distal
interphalangeal joint.
Comminuted fractures can be treated with a short period of immobilization
 Bony mallet injuries should almost universally be treated with immobilization. For large
fragments, simple pin fixation or dorsal blocking pin fixation can be considered
Proximal Interphalangeal Joint Injuries
The PIP joint is central to functional digital motion
Closed, simple dislocations are reduced under digital block anesthesia and tested for
stability following reduction.
If the joint requires less than 40 of flexion to maintain stability, a dorsal block splint is
applied, and early active flexion is started.
Long-term thickening of the PIP joint and residual stiffness are common sequelae.

Hyperextension and axial loading injuries of the PIP joint often result in dorsal
dislocation with varying degrees of fracture to the volar surface of the middle phalangeal
base
Fractures comprising less than 30% of the joint surface can typically be stablized with
dorsal block splinting alone.

Fractures occupying 30% to 50% of the joint have tenuous stability. If closed treatment is
selected for these injuries, careful follow-up is essential to recognize recurrent instability.
Fractures requiring more than 40 of PIP joint flexion to maintain stability or those
involving more than 50% of the joint surface should be treated surgically.

Static dorsal block pinning is favored in some instances because it is simple and avoids a
larger surgical exposure.
Open reduction and internal fixation of the volar lip is effective if the fragment is large.
Although fracture reduction may not be perfect, the applied traction stabilizes articular
and metaphyseal comminution, allowing sufficient joint remodeling so that stable
proximal phalangeal condylar containment is maintained.

Volar plate arthroplasty advances the fibrocartilaginous volar plate into the defect left
after resecting the comminuted and irreparable volar lip.
Hemihamate arthroplasty is an alternative to volar plate arthroplasty. It is based on
reestablishing the anatomic concavity of the volar lip and is indicated for comminuted
 fractures involving 50% or more of the volar lip; these fractures are not amenable to
fixation.

Metacarpophalangeal Joint Injuries

Although many metacarpophalangeal (MCP) joint injuries are irreducible, dorsal
dislocations of the MCP joint warrant an attempt at closed reduction.
Irreducible dislocations generally result from the interposition of the volar plate in the
joint and buttonholing of the metacarpal head between the flexor tendons and the radial
lumbrical.
Metacarpophalangeal Joint Injuries
Open reduction can be safely performed through a dorsal or volar approach.
With the volar approach, great care must be taken to protect the digital nerves, which
may be severely tented over the metacarpal head. The A1 pulley may be released to allow
retraction of the flexor tendons. The volar plate is then incised longitudinally, allowing
for reduction.

Injuries to the radial or ulnar collateral ligaments of the MCP joint are common,
particularly involving the thumb. Immobilization is adequate to treat partial tears or
nondisplaced avulsion fractures.
Acute injuries have been treated with primary repair and chronic injuries with tendon
graft reconstruction
Metacarpal Fractures
Metacarpal neck fractures may be treated nonsurgically with excellent functional
outcomes for angulations of 40 to 50 in the small finger, 30 in the ring finger, 20 in
the middle finger, and 10 in the index finger.
Deformities exceeding these limits should be reduced. If open reduction is necessary,
pinning across the fracture should be considered.
Metacarpal shaft fractures may be grouped into three general categories:
1. Transverse fractures are unstable but easily reducible. Some dorsal angulation is
acceptable, but generally, dorsal angulation exceeding 30 for the small finger, 20 for
the ring finger, and any dorsal angulation for the index and middle fingers should be
treated surgically
2. Oblique fractures introduce the potential for shortening and rotational malalignment,
which is poorly tolerated. Five degrees of malrotation can produce 1.5 cm of digital
overlap. The presence of malrotation is a key indicator for surgical management.
 3. Comminuted fractures lack inherent stability and should be treated surgically.
Surgical treatment is indicated in the presence of multiple fractures because of the loss of
supporting architecture in the adjacent digits, oblique fractures (especially those with
multiple comminuted fractures), open fractures (especially those associated with significant
soft-tissue injuries, and polytrauma patients who cannot tolerate cast immobilization.
A variety of percutaneous, interosseous, internal, and external fixation devices and
techniques are available for metacarpal fracture fixation. Each option offers the surgeon
relative advantages with respect to construct strength, ease of application, and cost. These
factors should be evaluated by the surgeon when selecting the appropriate treatment. All
options can afford excellent outcomes when properly applied.
Carpometacarpal Joint Injuries
Injuries to the carpometacarpal (CMC) joints are relatively uncommon. The metacarpals
are very congruously seated onto the distal carpal row with stout volar, dorsal, and
intermetacarpal ligament attachments. The CMC joints of the small and ring fingers act
as a mobile hinge allowing flexion, extension, and rotation toward the thumb; this
mobility predisposes those joints to injury more so than any of the other CMC joints.
Although pure dislocation is possible, these injuries more commonly occur as fracture-
dislocations with variable degrees of fracture through the hamate, metacarpal bases, or
both.
Closed reduction and percutaneous pinning of the metacarpal base to its neighbor or to
the carpus is frequently sufficient.
If a large portion of the hamate has been avulsed, open reduction and screw or plate
fixation may be performed.
A Bennett fracture is an intra-articular fracture of the thumb metacarpal base involving
avulsion of the thumb from the volar oblique ligament of the thumb CMC joint.
These injuries should be reduced with traction, extension, and pronation toward the small
finger. Once reduced, the position can be held with K-wires to the index metacarpal or
into the carpus.
A Rolando fracture is a pilon-type injury to the thumb CMC joint following axial
loading. This splits the thumb into diaphyseal, radial, and ulnar articular fragments.
Rolando fractures should generally be treated closed with joint unloading by means of a
mini- external fixator and supplemental K-wire stabilization of larger fragments
Fractures and dislocations of the wrist
Carpal Fractures and Nonunion
Acute Fractures
 Fractures of a carpal bone are usually caused by a fall onto an outstretched hand or by a
motor vehicle crash. Other causes include injuries caused by contact sports or a sudden
impact to the palm, as can occur in base- ball players or golfers.
The scaphoid is the most frequently fractured carpal bone, followed by the triquetrum and
lunate
Because the scaphoid is largely covered by cartilage and receives most of its blood
supply in a retrograde manner, fractures of this bone are more prone to complications
than fractures of the other carpal bones.
In general, scaphoid fractures that are nondisplaced or minimally displaced (< 1 mm) can
be treated by immobilization and have a union rate of approximately 90%.
Surgery is indicated for scaphoid fractures that are displaced, comminuted, located at the
proximal pole, have an intrascaphoid angle greater than 35, or those associated with an
ipsilateral distal fracture or perilunate dislocation
Open reduction can either be done through the volar or dorsal approach
Most triquetral and lunate fractures are avulsion in- juries of the dorsal capsule and are
the bony equivalent of a wrist sprain
Kienbck disease should be ruled out if a fracture line is seen in the coronal plane
through the body of the lunate.
Fractures of the hamate generally occur through the hook from a direct blow to the palm.
Nondisplaced fractures can be treated with im- mobilization. Internal fixation or fragment
excision can be considered for displaced hamate hook fractures
Symptomatic partial union or nonunion of the hook of the hamate is treated by excision.
Nonunion
Risk factors for scaphoid nonunion include proximal pole fractures, delayed diagnosis
and treatment, patient noncompliance, and comminution or displacement at the fracture
site
MRI with intravenous contrast is used to assess the vascularity of the proximal pole (such
as in cases of osteonecrosis) and the extent of arthritis
T1-weighted MRI scan with gadolinium intravenous contrast shows no enhancement of the
proximal pole of the scaphoid, indicating osteonecrosis in a patient with scapoid non union
CT is helpful in determining scaphoid morphology, including any humpback deformity.
The treatment of scaphoid nonunion is based on the location of the fracture, the presence
of osteonecrosis, the amount of deformity/collapse, and the extent of arthrosis.
Carpal Instability
 In an uninjured wrist, the bones of the proximal carpal row act together as an intercalated
segment to coordinate movements between the distal radius and ulna and the distal carpal
row.
It is believed that the scaphoid functions as a stabilizer of the midcarpal joint acting as a
bridge between the proximal and distal carpal rows.
In the proximal row, the lunate is attached to the scaphoid through the U-shaped
scapholunate interosseous ligament and to the triquetrum through the C-shaped
lunotriquetral interosseous ligament.
As the hand is radially deviated, the scaphoid flexes, causing the lunate and triquetrum to
follow into flexion. With ulnar deviation, the reverse occurs and the proximal row goes
into extension.
Scapholunate Dissociation
Disruption of the scapholunate interosseous ligament removes the scaphoid flexion
moment from the lunate, allowing it to assume an extended position under the influence
of the triquetrum. The scaphoid, in turn, falls into further flexion and supination, creating
incongruity at the radioscaphoid facet
This condition is termed dorsal intercalated segment instability.
Most patients with scapholunate dissociation will report wrist pain or weakness with
loading. Some patients will report a painful click or snapping sensation with motion.
Radiographs of a suspected scapholunate interosseous ligament injury should include PA
views in neutral, along with clenched fist, ulnar deviation, and lateral views
Radiographs of a scapholunate dissociation injury.
A, PA view shows widening of the scapholunate interval and a signet ring of the scaphoid. B,
Lateral view shows dorsal intercalated segment instability with a scapholunate angle of 90.
Lunotriquetral Dissociation
Lunotriquetral interosseous ligament tears usually occur in combination with other
intercarpal or radiocarpal ligament injuries, such as lunate or perilunate dislocations
Provocative maneuvers, such as the ballottement maneuver, and shuck and shear tests
may be positive
Magnetic resonance arthrography may show a dye leak at the lunotriquetral joint;
however, similar to other soft-tissue injuries about the wrist, arthroscopy remains the best
method for assessing the tear.
Immobilization is used to treat stable lunotriquetral ligament tears.
Lunate and Perilunate Dislocations
 Lunate and perilunate instability patterns are uncommon and represent injuries from
high-energy trauma.
In lunate dislocation, the lunate is completely displaced from its fossa (and capitate) and
comes to rest volar to the distal radius.
In a perilunate dislocation, the relationship between the distal radius and lunate is main-
tained, but the capitate assumes a position dorsal to the lunate

Young men are most prone to these injuries and often have associated injuries that may
require more urgent attention.
Closed reduction should be attempted for acute dislocations to prevent median nerve
compression.
Patients with progressive median nerve symptoms should be treated with a carpal tunnel
release; direct digital pressure on the lunate (through an extended carpal tunnel incision)
should readily reduce the dislocation.
Surgical exposure for this injury can be through a single dorsal incision or a combined
volar-dorsal approach.
Poor results can be expected after open injury or delayed treatment, and a primary
proximal row carpectomy should be considered.
Distal Radius Fractures
Distal radius fractures are the most common fractures of the upper limb and account for
approximately 20% of all fractures.
A large percentage of these injuries occur in older women with osteoporosis.
Despite the myriad of treatment options, restoration of painless function of the injured
wrist remains the ultimate goal.
The management of distal radius fractures should be individualized on the basis of the
fracture pattern, degree of displacement, other associated injuries, the patients activity
level, and the surgeons experience and preference.
Surgery is generally indicated for fractures that are open, unstable, have 2 mm or more of
articular displacement, or those that are a part of a multitraumatic injury.
The following conclusions can be reached from the literature on distal radius fractures:
1. Closed management or percutaneous pinning alone has worse radiographic outcomes
than external fixation augmented with percutaneous pins.
2. Internal fixation yields radiographic and clinical results that are at least comparable with
augmented external fixation.
 3. 3. Because internal fixation produces radiographic results comparable to external
fixation, internal fixation can be expected to provide radiographic results that are better
than those of casting or percutaneous pinning.
4. Internal fixation, especially with volar fixed-angle locking plates, is seemingly the
preferred treatment for most displaced or unstable distal radius fractures.
Distal Radioulnar Joint
The prime stabilizers of the DRUJ are the dorsal and volar radioulnar ligaments and the
triangular fibrocartilage.
The diagnosis of instability can be made with plain ra- diographs, although dynamic CT
with contralateral wrist comparison is more accurate
DRUJ instability most commonly results from a fracture of the distal radius
The conventional practice has been to fix associated ulnar styloid base fractures because
of the potential DRUJ instability caused by disruption of the radioulnar ligaments
SOFT TISSUE AND VASCULAR INJURIES
Trauma to the hand and wrist can result in injury to multiple structures depending on the
injury mechanism.
Tendons, joints, and bone are at risk with blunt trauma, whereas skin, blood vessels, and
nerves may be injured by sharp lacerations.
Partial tendon disruption from a closed injury may be difficult to diagnose with physical
examination; therefore, MRI or ultrasound may be needed.
Extensor Tendon Injuries
The treatment of extensor tendon injuries is largely dependent on the location and type of
injury.
Closed injury to the central slip (PIP boutonnire deformity) or terminal extensor tendon
(distal interphalangeal mallet finger) should be managed with splinting; in rare instances,
surgery will be needed.
Injury to the radial sagittal band can cause subluxation of the extensor digitorum
communis ulnarly, which can be managed with splinting orsurgery to centralize the
tendon over the MCP joint.
Flexor Tendon Injuries
Suspected flexor tendon injury warrants a careful examination to identify loss of active
flexion strength or motion, and any associated digital nerve injury
Injuries are classified by the anatomic zones:
 1. Zone I injury is distal to the flexor digitorum sublimis inser- tion, and the flexor
digitorum profundus is either avulsed from the distal phalanx or transected distal to the
A4 pulley.
2. Zone II flexor tendon injuries occur between the A1 and A4 pulleys. Both the flexor
digitorum sublimis and flexor digitorum profundus (along with the digital neurovascular
structures) can be involved.
3. Flexor tendon injuries that occur more proximally (zones III to V) are less common.
Acute lacerations should be repaired, but tendon transfers may be required for attritional
ruptures.
Nerve Injuries
Traumatic peripheral nerve injuries are a heterogeneous group of disorders that
commonly occur in conjunction with other soft-tissues trauma.
When possible, primary repair of the nerve should be done within the first 2 days after
injury to achieve the best possible functional result.
There should be minimal tension on the repair to allow for motion within 2 to 3 weeks.
When primary end-to-end coaptation is not possible because of tension or gapping,
autografting is the gold standard for treatment.
Tendon transfer can supplement a motor nerve re- pair. If done early, the transfer can act
as an internal splint to support function and prevent deformity during nerve recovery.
High-pressure injection injuries
Despite a relatively benign appearing entry wound, high-pressure injection injuries may
result in extensive soft-tissue damage.
The nondominant index finger is most commonly involved.
Grease, chlorofluorocarbon, and water-based paints are relatively less destructive, may be
successfully treated nonsurgically with parenteral antibiotics, elevation, and early
mobilization.
Industrial solvents and oil-based paints produce a high degree of tissue necrosis.
Emergent surgical dbridement and decompression is typically required following high-
pressure injection injuries
Broad-spectrum antibiotic coverage is important because the necrotic tissue resulting
from these injuries is a good culture medium for bacterial growth.
Compartment Syndrome
 Compartment syndrome has many causes, including decreased compartment volume
resulting from tight closure of fascial defects, the application of excessive traction to
fractured limbs, and the use of tourniquets, tight dressings, or splints.
It has been shown that no distinct fascia completely surrounds any of the intrinsic
muscles of the hand
Compartment syndrome of the hand is a surgical emergency.
If not treated within 24 hours, contracture becomes established in a matter of days with
muscle necrosis ultimately leading to fibrosis.
Late changes in missed diagnoses of compartment syndrome vary with the compartment,
but generally lead to a stiff hand and prolonged pain.
Digital Replantation
The criteria for digital replantation varies based on the experience of the surgeon, but the
goals are return of function of the replanted part and low morbidity to the remainder of
the limb and the patient as a whole
Typical indications include multiple digit traumatic amputations, thumb amputations,
through-the-palm amputations, major limb replantation, and almost any level of digital
amputation in a child
Typical contraindications to replantation include severe mangling of the amputated part,
segmental injury, serious comorbidities, and severely arteriosclerotic vessels.
Digital replantation in patients with psychiatric comorbidities is typically contraindicated.