The complex anatomy of the hand means that injuries result in substantial
loss of function. The damage must be repaired to regain the lost function.
Fractures need to heal in anatomic position, and the soft tissues must be
supple so that the fingers can move through a useful range of motion.
Evaluation and management of malunion, nonunion, bone loss, and stiff fingers
are discussed in this article.
Deformity is the most common complication following
fracture1,2.
While this paper focuses on the indications, techniques, and outcomes of
reconstructive surgery, it is clear that the optimal management of deformity
is prevention. Treatment of a fracture in the hand must include a careful
evaluation of rotational and angular alignment with the digits both extended
and flexed.
Deformity of the phalanges or metacarpals can be classified on the basis of
the involved bone, the location of the deformity (intra-articular or
extraarticular), the type of deformity (offset, angulation, rotation, or a
combination), the patient's age (child or adult), and whether it is an
isolated skeletal lesion or is associated with soft-tissue complications.
Phalangeal malunion may produce rotation; volar angulation; lateral
angulation; shortening; or, more often than not, a combination of those
deformities3-6.
Rotational deformities of as little as 10° can lead to scissoring of the
involved digit onto an adjacent
one7
(Fig. 1). Apex volar angular
deformities are more likely to occur following transverse phalangeal fractures
and result in a so-called pseudo-claw deformity. Lateral angular deformities
may be the sequelae of more complex injuries resulting in deficient bone on
one side of the diaphysis. Operative correction of either apex volar or
lateral angular malunion is achieved with either opening or closing wedge
osteotomies1,5,8,9.
Isolated phalangeal shortening may be the sequela of spiral, long oblique,
or highly comminuted fractures. On occasion, some compromise in digital
flexion results from an osseous spike projecting
volarly10,11.
Metacarpal deformity, a frequent result of fracture, is better tolerated
than deformities involving the phalanges and therefore may require operative
intervention less
often12-15.
Fractures of the metacarpal neck, or so-called boxers' fractures, are frequent
injuries and often result in flexion deformities at the fracture site, which
usually do not cause clinical problems. Deformities involving the metacarpal
neck of the index or long finger can produce functional problems such as a
prominent metacarpal head in the palm, especially if the volar angulation
exceeds 10°; deformities of as much as 50° may be well tolerated in
the metacarpal of the little
finger2,12-17.
Rotational deformities of <10° at the metacarpal level produce
minimal functional or cosmetic problems, but >10° of rotational
malalignment results in angular deviation and rotation of the involved
digit15,18-20.
While a volar angular malunion of the metacarpal neck may be well
tolerated, when this deformity lies closer to the middle of the diaphysis, the
functional and cosmetic problems are substantial. Midshaft malunion of
>20° in any of the four metacarpals usually requires operative
correction20-26.
Intra-articular malunions may result in pain, limited motion, and/or
deformity. Early intervention with osteotomy and realignment, when the
original fracture lines are still identifiable, may provide acceptable
results5,27-31.
The majority of reported cases in which intra-articular osteotomy was
performed have involved the proximal interphalangeal
joint27-30.
There is limited published experience regarding intraarticular malunions of
the metacarpophalangeal
joints21,30,31.
There has been more experience with intra-articular osteotomies of the base of
the thumb metacarpal, with the caveat that early recognition and intervention
are necessary for a successful functional
result30-36.
Alternatives to corrective osteotomy for intra-articular malunions include
excision of osteocartilaginous spurs, arthroplasty, or arthrodesis.
The evaluation of a malunited fracture should include a thorough assessment
of the overlying soft-tissue envelope, the neurovascular status, the articular
mobility, and the characteristics of the deformity itself. A simple deformity
consists of only a skeletal injury whereas a complex malunion involves
associated soft-tissue and/or articular dysfunction. Extra-articular malunions
can adversely affect the function of adjacent digits, limit the overall arc of
digital motion, disturb the normal muscle-tendon balance, or decrease grip
strength5,6,22,37,38.
Intra-articular malunions may result in a block to motion, capsular
contracture, synovitis, or
arthrosis5,27,29-31,38.
The radiographic evaluation must include anteroposterior, lateral, and
oblique projections, with similar views of the normal side for comparison. The
assessment of more complex deformities is aided by making true anteroposterior
and true lateral radiographs of the involved digit proximal to the deformity
and similar projections distal to the deformity. Tracings of these radiographs
can be used as cutouts to be superimposed on a tracing of the contralateral,
normal digit. Articular deformities may be better assessed with computed
tomography.
A number of parameters influence the timing of surgical intervention: the
time from the original injury, the state of the overlying soft tissue, tendon
mobility, articular mobility, and the neurovascular status. There is concern
about intervention between four and eight weeks after the injury, as
soft-tissue swelling may further limit the final motion and lead to a poorer
outcome5,38.
Therefore, before the corrective osteotomy is done, every effort should be
made to maximize joint mobility as well as limit soft-tissue swelling. This,
however, is not the case for an intraarticular malunion. The original fracture
lines often can still be appreciated for up to three months after the
fracture, and arthrosis is less likely to be present prior to six months after
the injury. It is better to correct the intra-articular malunion as soon as it
is recognized.
The type and location of an extraarticular osteotomy in the metacarpals or
phalanges depend on a number of issues. Whenever soft-tissue coverage permits,
the osteotomy should be performed as close as possible to the site of the
deformity. The type of osteotomy is based on the location of the malunion,
tendon balance, and any soft-tissue or articular contracture.
Proper exposure is crucial to gain access to the deformity, permit a
sufficient length of bone for skeletal fixation, and allow access for
capsulotomies or tenolysis, if needed. Before the osteotomy is performed, the
accuracy of the assessment as well as the correction of the deformity is
improved by using reference Kirschner wires placed perpendicular to the long
axis of the bone and proximal and distal to the site of the deformity.
Correction of the deformity is observed when the reference wires become
parallel in the frontal, axial, and lateral
planes5,39
(Fig. 2).
An incomplete osteotomy is appropriate for the vast majority of purely
angular deformities in the radial or ulnar
plane4,9,10,22,26,38,40.
Except when such deformities involve the middle or distal phalanges, an
opening wedge osteotomy restores skeletal length and resets the tension of the
extensor mechanism but requires more stable internal fixation. A closing wedge
can be created with use of sequentially larger burrs, with the opposite cortex
and periosteum left
intact40. Fixation
is obtained with use of small-gauge stainless-steelwire figure-of-eight loops
on the tension side. Dorsal or volar apex angular deformities are corrected
with an opening wedge osteotomy with an interposed bone graft, which requires
stable plate fixation as a result of the more substantial deforming forces of
the extrinsic
muscles5.
Pure rotational deformities require a complete, usually transverse
osteotomy. As thin a blade as possible should be used to create the osseous
cut. Some authors have suggested that a pure rotational malunion of the
phalanges can be corrected with a rotational osteotomy at the metacarpal
level4,20,41-43.
However, the amount of correction that can be achieved at this level is
limited. Gross and Gelberman found, in a cadaver study, that the deep
transverse metacarpal ligament limited metacarpal rotation to 19° in the
index, long, and ring fingers and to between 20° and 30° in the little
finger44.
Postoperative rehabilitation depends on the type of osteotomy, the security
of the fixation, and whether associated capsulotomy or tenolysis was done
(Fig. 3). When the fixation is
stable, early active motion is initiated, preferably under the supervision of
a trained hand therapist.
Nonunion involving the tubular bones in the hand is extremely
uncommon17,45.
While the definition of a nonunion depends to some degree on the time after
the fracture, the definition is best a functional one in that immobilization
of the hand for longer than three months to obtain union can lead to
functional
impairment46.
Causes of nonunion include loss of bone substance, inadequate immobilization,
fracture distraction, or infection. The indication for operative treatment
depends on both symptoms and functional disability. While a variety of
techniques have been described for the treatment of
nonunions47-50,
our preference has been stable internal fixation when the involved digit has
good functional
potential46.
Digital stiffness affects active or passive motion at the
metacarpophalangeal, proximal interphalangeal, or distal interphalangeal
joints. Stiffness may result from abnormal osseous or articular anatomy;
decreased compliance of the periarticular soft tissues such as the palmar
plate, collateral ligaments, fibrous flexor sheath, or skin; or loss of
differential excursion of any of the gliding tissues such as digital nerves,
arteries, flexor tendons, and extensor tendons. Once the abnormality is
properly identified and understood, the most efficacious treatment modalities
can be
instituted51-54.
The initial treatment must focus on the restoration of normal anatomy: the
reduction and stabilization of the joints and fractures with use of pins,
internal fixation, or external fixation; the repair of tendons, nerves, and
blood vessels; and the provision of adequate tension-free coverage with use of
local or distant flaps as required. Restoration of structure should supplant
the too-early attempt at restoration of function. Restoration of as many
injured parts of the finger as possible to their normal tension, length, and
continuity can improve the success rate of later treatment for restoration of
function.
Despite ideal treatment of the initial traumatic injury, structural
problems may persist and must be addressed when identified. Osseous and
articular causes of stiffness, such as arthrofibrosis and malunion (both
intra-articular and extra-articular), alter considerations for therapy and the
timing of surgery in the stiff finger. For example, a large osseous prominence
located volarly in the subcondylar recess at the proximal interphalangeal
joint will prevent the restoration of full flexion of the proximal
interphalangeal joint while also limiting full tendon glide. The osseous
abnormality must be corrected to allow full functional recovery. In general,
severe arthrofibrosis or decreased digital flexion because of intra-articular
pathology, extra-articular osseous blocks to flexion or extension, or
extension-type malunion of the proximal phalanx should be treated before any
intervention is carried out to address the soft tissues. Therefore, a useful
principle of treatment is that arthrolysis, joint replacement, osteotomy, or
ostectomy be performed early to allow optimization of the postoperative
rehabilitation of the soft tissues and gliding tissues.
In addition, the successful surgical correction of a chronically stiff
digit requires a stable, complete, and compliant soft-tissue envelope. Split
or full-thickness skin grafts may provide stable coverage of epitenon, digital
sheaths, arteries, and nerves, but they form poor gliding surfaces for the
restoration of easy digital motion. Replacement of such grafts with local or
distant flaps may be necessary prior to the consideration of tenolysis and
capsulectomy.
Once the structural abnormalities have been addressed, therapy should be
designed to maximize the digital range of motion. Surgical intervention should
be considered only after a specific therapy protocol to address each cause of
the digital stiffness has been fully carried out without success. Surgical
decision-making hinges on accurate assessment of the active and passive ranges
of motion of the proximal interphalangeal and, to a lesser extent, the
metacarpophalangeal joints. While some have ascertained that a combined arc of
flexion (metacarpophalangeal, proximal interphalangeal, and distal
interphalangeal motion) of >170° is required for adequate
function1,2,4,
a greater total arc of motion is often required on the ulnar side of the hand
to facilitate power grasp and a lesser arc may be tolerated well on the radial
side of the hand for fine thumb-index pinch activities. Likewise, full digital
extension may be required on the radial side of the hand but is less important
on the ulnar side, where digital flexion assumes greater importance. Each
digit, and indeed each patient, must be evaluated individually to determine
the appropriate surgical tactics for the restoration of passive and active
flexion and extension. When the patient thinks that his or her digital arc of
motion is insufficient to allow daily activities of self-care, leisure, and
work, surgery is indicated to improve that motion.
The correction of soft-tissue-related stiffness begins with a clinical
examination of the active and passive flexion and extension of the finger.
Four questions are asked during clinical examination to help in preoperative
planning: (1) Can the finger be flexed passively? (2) Can the finger flex
actively? (3) Can the finger be extended passively? (4) Can the finger extend
actively? By definition, fingers that lack passive motion in a particular
direction also lack active motion in the same direction. The answers to these
questions will reliably reveal the location of the abnormal tissue as well as
the surgical approach needed to address it.
Six possible permutations of finger stiffness are seen clinically, and a
clearer definition of each aids in management decisions.
Type 1: Fingers that can be neither passively flexed nor passively
extended have both dorsal disease (extensor tendon adhesions and/or dorsal
capsular tightness and tightness of the dorsal collateral ligament) and palmar
disease (A2 pulley insufficiency, palmar plate contracture, tightness of the
accessory collateral ligament, checkrein contractures, or skin deficiency)
preventing motion. This clinical state is often encountered in stiff fingers
following replantation or penetrating trauma. The presence or absence of
adhesions of the intrasynovial flexor sheath cannot be assessed directly,
since the presence of dorsal disease precludes direct evaluation of active
finger flexion. It is our preference to release the volar capsular proximal
interphalangeal contracture and provide a stable compliant softtissue cover
(with either local or distant flaps) as initial treatment. Following
correction of the flexion deformity in these fingers, we perform a dorsal
capsular and collateral ligament release and an extensor tenolysis in the
initial surgical setting. We do not operate on both the dorsal and the palmar
aspects of the finger at the same time, as swelling may make it impossible to
maintain the surgical gains during postoperative motion therapy. We prefer to
obtain passive flexion first, and then, if necessary, to address the lack of
active flexion later. In addition, palmar contracture can be addressed at the
time of flexor tendon lysis or reconstruction. If a dorsal release and
extensor tenolysis is performed with the use of a local anesthetic, active
finger flexion can be evaluated directly by asking the patient to flex the
finger in the operating room. If a regional or general anesthetic is employed,
a traction test is performed with use of the flexor digitorum profundus tendon
of the affected finger. If these tests demonstrate flexor tendon adhesions,
the flexion contracture release and flexor tenolysis can be performed in the
same surgical setting.
Type 2: Fingers that can be neither passively flexed nor actively
extended have dorsal extensor adhesions and/or dorsal joint and collateral
ligament contractures without palmar contracture. As in the Type-1 finger (but
more commonly encountered), the dorsal contracture prevents a preoperative
assessment of the flexor mechanism. Treatment includes a dorsal extensor
tenolysis and soft-tissue release followed, if necessary, by a flexor tendon
tenolysis or reconstruction as a staged procedure once full passive finger
flexion has been achieved. In cases in which internal fixation implants have
been used, removal of the implant with resection of the ipsilateral lateral
band and transverse retinacular ligament is combined with extensor tenolysis
to restore passive digital flexion.
Type 3: These fingers can be neither actively flexed nor passively
extended, but unlike the first two groups they can be passively flexed.
Passive flexion demonstrates that there are no clinically important extensor
adhesions, dorsal capsular tightness, or tightness of the dorsal collateral
ligament. Surgical treatment, therefore, focuses on the volar aspect of the
finger. A palmar contracture prevents finger extension; all potential
etiologies, as mentioned above, need to be considered in the preoperative
planning. With a palmar softtissue deficiency, as seen in a burn or a complex
palmar laceration with softtissue loss that has been allowed to heal by
secondary intention, new, vascularized skin may be necessary to restore a
gliding surface for the flexor tendon. Lack of active finger flexion suggests
either flexor tendon adhesions or flexor tendon discontinuity (as discussed
below for Type 6). Exploration of the flexor sheath is necessary to discover
the cause.
Type 4: Fingers that can be neither actively flexed nor actively
extended are very uncommon, and these limitations are related to an
incompetent flexor and extensor mechanism. There is full passive motion of
these fingers. Passive flexion indicates no clinically important dorsal
disease, and intact passive extension denotes the absence of a palmar flexion
contracture. These fingers typically have intrasynovial flexor adhesions
requiring tenolysis or they have flexor tendon discontinuity as well as
extensor dysfunction secondary to either lateral band subluxation palmar to
the axis of rotation of the proximal interphalangeal joint (i.e., boutonniere
deformity) or an extensor tendon repair that has healed in the lengthened
position, or both. The extensor side is reconstructed first, as prolonged
postoperative joint immobilization following extensor reconstruction is often
required. Once maximum active extensor improvement has been achieved, flexor
tenolysis or reconstruction is done as long as complete passive finger flexion
is maintained.
Type 5: Fingers that cannot be extended passively are very common,
and the limitation is caused by isolated palmar soft-tissue contracture. These
fingers can, by definition, be fully flexed actively, but the presence of a
flexion contracture prevents full digital extension. This situation is most
commonly seen in patients with Dupuytren contracture. It may also be seen in
patients with volar soft-tissue defects that were allowed to heal by secondary
intention. Patients often tolerate small degrees of deformity; however, when
the contracture becomes severe, surgical release with or without soft-tissue
reconstruction may be necessary.
Type 6: Fingers that have full active extension but lack active
flexion have a deficient flexor mechanism. The dorsal joint capsules,
collateral ligaments, and extensor tendons are continuous and of normal
tension and compliance, but either intrasynovial adhesions of the flexor
tendon or elongation or rupture of that tendon results in incomplete active
finger flexion. Direct surgical exploration is the only definitive way to
assess the cause of the lack of active flexion.
Exploration and restoration of active digital flexion may require one, two,
or three surgical stages. All surgical protocols begin with a direct
exploration of the flexor tendon, its pulley system, and its soft-tissue
surroundings. The flexor tendon may be intact, intact but lengthened, or
ruptured. In addition, the flexor sheath is assessed for the presence of
restrictive intrasynovial adhesions. If the tendon is in continuity but has
decreased intrasynovial excursion due to adhesions, a flexor tenolysis is
performed and early postoperative mobilization rehabilitation is begun. If the
flexor tendon is intact but elongated at the repair site and surrounded by
restrictive adhesions, aggressive surgical lysis of adhesions is performed. A
less vigorous rehabilitation protocol, a so-called frayed-tendon protocol, may
be required to decrease the risk of subsequent tendon rupture. If the tendon
is ruptured (or lengthened by >3 mm), the first decision to be made is
whether a primary repair of the tendon is possible. If the proximal
muscle-tendon unit is not adherent and has good excursion, and the proximal
stump can be advanced without undue tension, repair may be performed. Usually,
this is the case only in the first few weeks following laceration and repair,
although in our experience repairs done as late as three months following
injury are sometimes successful. If primary repair is not possible, either
intrasynovial tendon grafting or placement of an inert silicone rod can be
done. Primary tendon grafting can be performed if the A2 and A4 pulleys are
intact; typically, a silicone rod is placed if a pulley must be reconstructed
(or if the flexor tendon sheath bed is poor). If a silicone rod is placed,
tendon-graft reconstruction is typically performed between three and six
months later. Following rod placement and exchange, a third surgical
procedure, flexor tenolysis, may be required depending on the patient's
propensity toward scar formation and his or her adherence to the rigors of the
rehabilitation protocol.
The treatment of a ruptured flexor digitorum profundus tendon with an
intact flexor digitorum superficialis tendon is controversial; it is typically
our preference to avoid grafting of a flexor digitorum profundus in the
setting of an intact flexor digitorum superficialis tendon. We have found
fingers with only an intact flexor digitorum superficialis to be highly
functional and, if necessary, a distal interphalangeal stabilization procedure
can be performed.
Bone loss within the hand is defined as incomplete contact of the skeletal
segment despite anatomic positioning of the main osseous fragments. The
adverse sequelae of bone loss include delayed union or nonunion, progressive
deformity, and/or failure of internal fixation.
When analyzing this condition, one must consider a number of factors,
including the bone involved, the location in the bone (intra-articular or
extraarticular), whether the loss is terminal or intercalated within the bone,
and the actual size of the defect. Coexistent problems may include loss of
functional tissue, inadequate soft-tissue coverage, necrosis of adjacent bone
segments, and active
infection55-58.
Management of bone loss in the hand depends on both the functional deficit
and the specific features of the reconstruction. Bone grafts or bonegraft
substitutes may function to fill a void, to provide structural support, or
even to replace articular cartilage. Alternative techniques include skeletal
shortening, arthroplasty, and distraction osteogenesis.
Bone grafts are classified by their type, the location of the donor site,
and the intended function. Autogenous grafts include pure
cancellous59,
corticocancellous58,60,
cortical strut61,
osteochondral, and vascularized grafts either as isolated units or within
composite transfers such as vascularized
joints62 or
toe-to-hand transfers for the treatment of terminal loss.
Autogenous cancellous grafts offer the potential for both osteoinduction
and osteoconduction, limited donor-site morbidity, ease of filling of the
often three-dimensional aspects of an osseous defect, and rapidity of
incorporation. The major disadvantage is a lack of structural support, which
can be offset by either internal or external skeletal
fixation63. A
useful technique is to create a compact cancellous graft for defect
replacement. This is done by impacting cancellous bone into a small syringe
with a diameter equivalent to that of the missing bone segment
(Fig. 4).
Corticocancellous bone grafts provide some element of structural support
and are particularly useful when an osseous defect requires reconstruction.
Restoration of skeletal length in phalangeal reconstruction is important to
restore tendon balance and proper digital motion. Boulas et al. described the
use of interposition corticocancellous graft along with plate-and-screw
fixation in the reconstruction of a traumatic proximal interphalangeal
loss64.
We recommended placement of the cortical aspect of the bone graft
anteriorly to facilitate screw purchase as well as to enhance stability by
having the stronger aspect of the graft help to resist increased bending
forces on the flexor side of the digit
(Fig. 5). Buchler and Aiken
described reconstruction of an area with partial articular loss with use of
osteochondral grafts from the
foot65.
Vascularized bone transfers for the treatment of osseous defects in the
tubular bones in the hand are either composite vascularized toe-joint
transfers (Fig. 6) or
vascularized toe-to-hand transfers for the treatment of terminal osseous loss.
These transfers also offer the potential for longitudinal growth in a
child.
There are few indications for the use of allograft and bone-graft
substitutes to replace bone loss in the hand. Bone-graft substitutes provide
no structural support. Allograft bone replacement, while avoiding donor site
morbidity, has a number of potential disadvantages, including resorption,
infection, a potential immunogenic inflammatory response, and limited and slow
revascularization. Perhaps the optimal application is to enhance the
reconstruction of metacarpal lengthening by placing a corticocancellous
allograft following distraction lengthening with external skeletal
fixation.