Most carpal and hand injuries in children are treated nonoperatively. The
purpose of this lecture is to identify those clinical situations that require
operative intervention. Complications from pediatric hand fractures,
dislocations, and soft-tissue injuries are most commonly due to the failure to
identify and treat an injury requiring an operation acutely. This lecture will
also review surgical techniques for specific injuries of the carpus and hand
in children. With regard to the wrist, this discussion will include the
indications for open reduction of scaphoid fractures, treatment of scaphoid
nonunions, and arthroscopic examination and treatment of chondral and
ligamentous injuries. Distal injuries that are treated surgically include
Seymour fractures, phalangeal neck injuries, and intra-articular
fractures.
Look for this and other related articles inInstructional
Course Lectures, Volume 57, which will be published by the
American Academy of Orthopaedic Surgeons in March 2008:• "Surgical Management of Forearm and Distal Radius Fractures
in Children and Adolescents," by Charles T. Price, MD
Look for this and other related articles inInstructional
Course Lectures, Volume 57, which will be published by the
American Academy of Orthopaedic Surgeons in March 2008:
• "Surgical Management of Forearm and Distal Radius Fractures
in Children and Adolescents," by Charles T. Price, MD
A scaphoid fracture is the most common carpal injury in children, and it
has become more common during the last decade or
two1-3.
The increased participation in competitive youth sports may account for the
increased incidence of these fractures. As in adults, scaphoid fractures are
classified by the location, degree, and direction of fracture displacement.
Distal pole, waist, and proximal fractures all occur in children, with waist
fractures being the most
common4,5.
As in adults, displacement beyond 1 to 2 mm is associated with malunion or
nonunion in
children6.
Determining the amount of displacement can be difficult, and computed
tomography or magnetic resonance imaging is an important evaluation for this
purpose and can be of help as a guide in the treatment of these
fractures7-10.
Osteonecrosis also occurs in children, especially in those with a displaced
proximal waist or proximal pole
fracture11.
Nondisplaced distal pole fractures usually heal without
complications12-19.
Plain radiographs or, if appropriate, computed tomography scans are closely
inspected to detect distal intra-articular extension or displacement.
Immobilization in a long or short arm thumb spica cast for up to six weeks is
recommended to protect healing of the distal pole fracture. Nondisplaced waist
fractures in a child or adolescent are also generally treated with cast
immobilization, and there is some evidence that initial use of a long arm cast
is more
efficacious15.
Computed tomography scans are indicated to be certain of three-dimensional
anatomic alignment. Cast immobilization is continued until complete healing
has occurred. At times, a computed tomography scan is required to confirm
healing. Because there is a risk of both nonunion and osteonecrosis even with
nondisplaced waist fractures, and as a result of concerns about prolonged
immobilization, percutaneous intraosseous screw fixation has been used more
commonly in adults with nondisplaced scaphoid
fractures20,21.
This technique has been carried over to the treatment of adolescents who
desire earlier mobilization. Under fluoroscopic guidance, a cannulated screw
can be placed from distal-volar to proximaldorsal or vice versa. The technique
is demanding, and its use depends on the fracture's location and the surgeon's
skills. The pin and cannulated screw must be placed centrally in both the
anteroposterior and the lateral plane. Misplacement of the screw increases the
risk of nonunion with osteolysis about the screw.
Displaced waist fractures require anatomic reduction and stable fixation.
This is usually performed by open reduction and internal
fixation6,17,22-26.
A volar approach to the scaphoid is the most common because the dorsal blood
supply is protected and the flexion displacement can be reduced. On rare
occasions, bone graft is required in the acute setting to correct a humpback
deformity due to volar fracture comminution. Smooth-wire or intraosseous screw
fixation has been utilized after anatomic reduction. More recently,
arthroscopic-assisted reduction and fixation has been performed for acutely
displaced scaphoid fractures. This is more technically demanding. Arthroscopic
inspection and manipulation of the fracture site to obtain anatomic alignment
for cannulated pin and screw placement is performed under both fluoroscopic
guidance and arthroscopic visualization.
A splint or cast is used after surgery as deemed necessary by the surgeon
to prevent excessive stress on the healing fracture. Generally, postfracture
stiffness from prolonged immobilization is not as much of a risk in an
adolescent as it is in an adult.
The proximal fragment of a proximal pole scaphoid fracture is at high risk
of being necrotic and of not healing to the body of the scaphoid. Percutaneous
screw fixation before fracture displacement or fragmentation may be useful in
the treatment of this rare fracture in an adolescent. Perfect placement of the
screw, centrally in both planes, is necessary in this situation to lessen the
risk of complications. An established proximal pole nonunion with displacement
may require reduction, vascularized bone-grafting, and internal fixation to
achieve healing (Figs. 1-A,
1-B, and
1-C)11.
Nonvascularized grafting and internal fixation is not recommended because it
has a high rate of failure.
Treatment of scaphoid nonunions in adolescents is similar to treatment in
adults2,27-34.
If the fracture is truly nondisplaced, prolonged cast treatment or
percutaneous screw fixation can be considered. Adjunctive electrical
stimulation has been utilized. Most scaphoid fracture nonunions, however, are
displaced and may have a necrotic proximal pole fragment. This situation
requires internal fixation and bone-grafting
(Figs. 2-A and 2-B).
Smooth-wire fixation was used in the past, but screw fixation is preferred
now. Autologous bone-grafting techniques are most often used to restore
structural integrity and expedite
healing30,31,33,34.
Most nonunions treated with reduction, internal fixation, and bone graft heal
in children and adolescents. The reason to treat a nonunion surgically is to
prevent long-term complications such as pain, stiffness, and
arthrosis35,36.
The hand is the most commonly injured body part of a child. In the toddler,
the fracture is usually a crush injury, such as occurs when a hand gets caught
in a
door37-45.
In the older child, the fracture is usually secondary to recreational sports.
Most of these injuries heal without
complications46.
However, there is a subset of fractures, dislocations, and soft-tissues
injuries that have dire consequences if not treated appropriately
initially.
Distal Phalangeal Injuries
A crush injury to the distal aspect of the finger is the most common hand
injury in a toddler. The distal tip can be partially or completely amputated
by the injury. Nail bed and nail plate injuries are usually associated with
distal phalangeal fractures, which range from minor avulsions to comminuted
open fractures. The growth plate is usually not involved except in the case of
a Seymour fracture, which will be discussed below. Most of these injuries can
be cared for in the emergency department with use of local anesthesia and/or
conscious sedation, but more complicated injuries should be repaired in an
operating room with the patient under general anesthesia. With partial
amputations, the dorsal skin, nail bed, and eponychial regions are usually
lacerated but there is an intact, viable volar skin bridge. With adequate
facilities in the emergency department and with the aid of loupe
magnification, the nail bed can be anatomically and delicately repaired with
absorbable suture after removal of the nail
plate47-50.
Most of these injuries heal without permanent nail deformity. Parents and
primary care physicians are advised to obtain a reevaluation if there is a
nail deformity at six months after the injury.
Complete amputations of the distal tip are treated with various techniques,
depending on the surgeon's experience and preference as well as the size and
orientation of the
defect51-56.
If the skin loss is minimal, irrigation and débridement as well as
coverage with a sterile nonadherent dressing is appropriate. Healing by
secondary intention will be relatively rapid and uncomplicated in a young
patient. At times, acute treatment requires minimal débridement of
exposed bone with a rongeur. Since the proximal physis has not been violated,
longitudinal growth will be unimpaired and the length of the digit eventually
will be nearly normal. More extensive loss can be treated with composite
grafting with use of the amputated part, pedicle grafting such as with an
advancement or a thenar flap, or skin or composite grafting from distant donor
sites. Attachment of the amputated part as a composite graft can be performed
acutely in the emergency department after débridement of both the part
and the amputation site. Healing following use of this technique is more
prolonged than that following use of local dressings alone, but it may result
in greater bulk and less risk of nail deformity from an extensive injury.
Injuries through the proximal quarter to third of the nail area are candidates
for surgical correction. Flap or donor grafting is usually performed
semi-acutely.
A mallet finger deformity in a child is similar to one in an adult, with
disruption of the extensor tendon as it inserts onto the dorsum of the distal
phalanx. The extensor tendon inserts on the epiphysis in a child, while the
flexor digitorum profundus inserts on the metaphysis. A true mallet injury
occurs either through an osseous avulsion or through an intrasubstance tendon
injury, whereas a Seymour fracture, which occurs through the physis, is not a
true mallet injury. A true mallet injury, regardless of type, can be treated
with immobilization of the distal interphalangeal joint in an extension splint
while allowing motion of the proximal interphalangeal joint. Successful
healing can be expected if the patient complies with instructions for splint
wear. This is true even for treatment of a chronic mallet finger deformity,
although there are rare cases of chronic mallet injuries requiring
reconstruction to achieve improved active extension. Tenodermodesis involves
advancement and repair of the disrupted tendon with advancement and suture
repair of the skin and subcutaneous tissues to the
tendon57. The risk
of this procedure is loss of flexion or the creation of a nail plate
deformity, but active extension can be improved.
A flexion injury in a child that results in a physeal separation between
the extensor tendon dorsally and the flexor digitorum profundus insertion
volarly is called a Seymour
fracture58.
The germinal matrix of the nail bed may be interposed in the physeal fracture
site and prevent reduction (Figs. 3-A and
3-B). Often, the flexed digit is misinterpreted as a mallet finger
and incorrectly treated with dorsal splinting. These open wounds can become
infected if left without appropriate treatment. Optimum treatment requires
early recognition and management. Treatment includes removal of the nail
plate, delicate removal of the entrapped germinal matrix from the physis,
reduction of the fracture, and repair of the nail bed. Usually, the phalangeal
fracture is stable after the soft-tissue repair. At times, pin fixation of the
distal phalanx and interphalangeal joint for three to four weeks protects the
nail bed repair and maintains fracture alignment.
Phalangeal Neck Fractures
Injuries to the subchondral region of the proximal or middle phalanx are
common with more proximal crush injuries, such as closure of a door on a
child's finger. As the child attempts to extract the digit from the door, the
greatest force occurs across the subchondral region and it fractures. The
resultant phalangeal neck fracture can displace dorsally and into extension
(Figs. 4-A, 4-B, and
4-C)59.
Radiographically, the distal fragment appears small because much of the
articular surface is cartilaginous in young patients; therefore, the severity
of displacement and its effect on adjacent interphalangeal joint motion can be
underappreciated. Failure to treat this injury with anatomic reduction and pin
stabilization can result in a malunion that limits digital flexion. At the
proximal interphalangeal joint, obliteration of the subcondylar fossa can
result in marked loss of digital motion. There also can be an element of
malrotation to the fracture. It is imperative that these injuries be
recognized and treated early. They are usually unstable injuries that
redisplace after closed reduction and cast immobilization. This is difficult
to appreciate on radiographs made with the hand in a cast. Closed reduction
and stabilization with one or more distal-to-proximal oblique pins for three
to four weeks is the recommended treatment. Children who present with an
incipient malunion can frequently be treated either with percutaneous pin
reduction and
stabilization60 or
with a careful open reduction that protects the blood supply to the distal
fragment through the collateral ligaments. Treatment of an established
malunion is more complex. In a very young patient, it may remodel with growth,
especially at the middle
phalanx60,61.
However, as the physis is proximal, this process will be slow (one to two
years) and may not be sufficient. Subchondral fossa reconstruction through a
volar approach will improve but not normalize
motion62. Clearly,
the best option is accurate recognition and treatment of this injury in the
acute setting.
Malrotation Fractures
Any phalangeal or metacarpal fracture can result in digital malrotation
regardless of its radiographic appearance
(Fig. 5). It is imperative to
perform a clinical examination to inspect digital alignment. Through a
tenodesis effect, passive wrist extension results in passive digital flexion
and allows assessment of digital alignment. Asymmetric convergence or
divergence of the fractured digit will be apparent even in the acute setting
with this examination. All malrotated digits require anatomic reduction and
operative stabilization. Most commonly, malrotation is caused by oblique
phalangeal and metacarpal fractures involving the border digits. However,
physeal, transverse, and intra-articular fractures can all lead to
malrotation. Treatment consists of smooth-pin stabilization or internal
fixation. A high index of suspicion and careful clinical examination are
critical to identify a potential malunion.
Intra-Articular Fractures
Any intra-articular fracture requires anatomic alignment and stability
during healing. Some injuries are nondisplaced and stable and can be treated
with closed means. However, careful follow-up clinically and radiographically
during the healing phase is necessary to be certain that there is no loss of
alignment. This may require out-of-cast radiographs to accurately assess joint
alignment. Displaced fractures require reduction and pin or screw
stabilization40,63,64.
At the middle phalanx, these injuries can involve central osteochondral
fragmentation. Careful operative dissection and anatomic reduction is
necessary to lessen the already real risk of osteonecrosis in these fractures.
At times, acute bone-grafting is necessary to achieve stability. The olecranon
distal to the apophysis is a reasonable source of cortical bone graft in a
child.
These injuries can be unicondylar, bicondylar, or comminuted. The
interphalangeal joint is always at risk for permanent loss of motion with any
juxta-articular or intra-articular injury. Permanent articular incongruity
clearly increases that risk, and anatomic reduction is the treatment of choice
for these injuries. Most often, this can be achieved in children with
percutaneous pin reduction and fixation. If reduction or stabilization cannot
be achieved with closed means, an open procedure involving pin or screw
stabilization should be done. Extreme comminution requiring distraction
treatment is rare in children and
adolescents65,66.
Postoperative rehabilitation to regain interphalangeal joint motion is
necessary to lessen the risk of a flexion contracture. Intra-articular
malunion is a difficult problem to manage, with loss of motion and pain being
common and a substantial risk of arthrosis (Figs.
6-A and
6-B). Unfortunately,
intra-articular osteotomies performed late result in less-than-desired results
in terms of motion, even when the radiographic appearance is improved.
Displaced Salter-Harris type-III intra-articular fractures of the thumb are
the pediatric equivalent of the gamekeeper's injury in the
adult67,68.
Rather than the ulnar collateral ligament of the metacarpophalangeal joint
being injured in a fall, such as in downhill skiing, the epiphysis fractures.
A displaced epiphyseal fracture of the proximal phalanx results in articular
and physeal incongruity. Open reduction and pin fixation is required
(Figs. 7-A and 7-B). Surgical
dissection into the joint should be through the fracture site and distal to
the intact ulnar collateral ligament insertion. When anatomically realigned,
these injuries heal in four to six weeks without complications. When
unrecognized or left malreduced, they can result in a nonunion or malunion
that is painful and limits motion and function. Similarly, displaced
intra-articular fractures of the base of the first metacarpal require anatomic
articular reduction and pin stabilization. The oblique ligament between the
first and second metacarpals holds the ulnar basilar fragment in place while
the abductor pollicus longus dynamically displaces the larger radial fragment.
Reduction involves restoration of length and correction of the angulation and
malrotation. Two or three percutaneous pins placed into the adjacent
metacarpal base and the carpus provide stability until the fracture heals. The
rare comminuted intra-articular fracture requires careful open reduction.
Severely comminuted injuries that are best treated with distraction techniques
in adults almost never occur in children.
Dislocations
Most interphalangeal joint injuries are "jammed fingers" at the
proximal interphalangeal joint secondary to a hyperextension force such as
from a thrown basketball. This results in a volar plate injury and, at times,
a minor avulsion fracture of the volar aspect of the middle phalangeal
epiphysis. These injuries can be overtreated with immobilization, which can
result in stiffness of the interphalangeal joint. Complete dislocations can
usually be reduced with distraction without complications. If the joint is
reduced and stable with motion, treatment involves brief splint protection and
mobilization within five to ten
days69. Buddy
taping is frequently used for protection, while active and passive mobility is
stressed. The rare avulsion fracture of the base of the middle phalanx that
results in a displaced, unstable joint is drastically different
(Fig. 8). This injury requires
joint reduction and mobilization only within the stable flexion-extension
arc70. Fluoroscopic
examination is necessary to determine the safe arc of motion. Dorsal splint or
pin extension blocking is used to prevent joint subluxation. Progressive
extension as stability is restored with healing is performed carefully to
maintain joint reduction while achieving maximum interphalangeal motion. These
injuries heal over six weeks, and therapy to regain maximal motion can be
prolonged. Periarticular swelling often lasts three to six months.
Most interphalangeal joint dislocations are uncomplicated. Dorsal
dislocations are most common and often are treated at the site of the injury
with reduction with gentle distraction by the patient, trainer, parent, or
coach. These injuries are usually stable after reduction as long as another
hyperextension force is avoided during volar plate and collateral ligament
healing. Again, early protected mobilization is advocated to lessen the risk
of longterm stiffness. A metacarpophalangeal joint dislocation is more likely
to be irreducible (a so-called complex
dislocation)71-76.
An irreducible dorsal dislocation of either the interphalangeal or the
metacarpophalangeal joint is usually secondary to volar plate entrapment. In
the metacarpophalangeal joint, this may be evident radiographically by
sesamoid interposition or bayonet apposition alignment. Closed reduction is
not feasible. Open reduction through either a
volar72,73,77-82
or a dorsal82
approach is necessary. If a volar approach to an irreducible
metacarpophalangeal joint dislocation is utilized, extreme care is necessary
to protect the displaced radial digital neurovascular bundle. Early protected
mobilization is important to lessen the risk of
stiffness80,81.
Soft-Tissue Injuries
The most common mechanism of a flexor tendon injury in a child is a
laceration from broken glass. In these injuries, the skin wound often appears
minor relative to the severity of the underlying soft-tissue injury. Failure
to perform isolated tendon and nerve testing can result in a delayed or missed
diagnosis. Wrist lacerations often involve multiple tendon and, at times,
major nerve or blood vessel lacerations. Obviously, an ischemic digit is an
operative emergency. Acute operative exploration and repair of these
soft-tissue lacerations in a young child are recommended because of the
limited ability to thoroughly examine the child. Palmar or digital lacerations
require careful examination to detect partial or complete nerve, tendon, or
arterial lacerations. Too often, digital nerve or isolated flexor tendon
injuries are missed acutely. A repair delayed for up to two to three weeks can
be uncomplicated, but beyond that the prognosis for recovery is worse.
Microscopic digital nerve repairs in children and adolescents generally enable
the full recovery of discriminatory sensibility. Postoperative protection is
necessary for only two weeks or so. Flexor tendon repairs are more
complicated, but the results are generally better than they are in adults.
There is debate about cast immobilization compared with protected mobilization
after a flexor tendon repair. Cast immobilization for four weeks has been
found to have more favorable results than protected flexor tendon mobilization
protocols with regard to the return of a total active arc of motion and a
lower incidence of tendon rupture in
children83.
So-called jersey finger avulsions of the flexor digitorum profundus
insertion occur in children and adolescents. The fusiform swelling in the
flexor tendon sheath can be mistaken for a jammed or sprained finger. Since
the flexor digitorum superficialis is intact, the patient can move or flex the
digit at the proximal interphalangeal joint when asked. Unless isolated
profundus tendon function is tested, the tendon rupture will be missed in the
acute or semi-acute setting. A true lateral radiograph may show the distal
phalangeal avulsion fracture and the location of the proximally displaced
tendon. Acute repair involves reinsertion of the tendon or the attached
osseous fragment into the volar aspect of the distal phalanx. This may require
repair over a dorsal button. Since the injury is in zone I, acute repair
usually has an excellent result. Late reconstruction, however, is much more
complicated. There is insufficient information in the literature to determine
whether it is better to leave the patient with a superficialis-only finger or
to perform a complicated free-tendon-graft reconstruction. Therefore, the
surgeon's and patient's preferences still play a large role in the
decision-making.
A complete amputation proximal to the level of the trifurcation of the
digital arteries in a child is considered an indication for replantation. A
crush injury that results in an amputation is associated with a higher rate of
failure of replantation than is an amputation caused by a sharp
laceration84.
Microscopic repair that results in prompt capillary refill and instantaneous
restoration of arterial flow intraoperatively is a positive sign of viability
of the reimplanted digit. The techniques of replantation in a child are the
same as those in an adult. Digital survival after replantation is most
probable with sharp amputations, a body weight in excess of 11 kg, repair of
more than one vein, bone shortening and interosseous wire fixation, and vein
grafting of arteries and veins as
needed84.
In summary, most carpal and hand injuries in children can be treated
nonoperatively. It is imperative that the treating physician identify those
clinical situations that require operative intervention. Complications from
pediatric hand fractures, dislocations, and soft-tissue injuries are most
commonly due to a failure to identify and treat an injury requiring an
operation acutely. The injuries include (1) intra-articular fractures, (2)
phalangeal neck fractures, (3) malrotated fractures, (4) scaphoid fractures,
and (5) tendon injuries. Prompt and appropriate surgical treatment of these
selected injuries usually leads to an excellent outcome.