Hand and Wrist

The superficial nature of the wrist relative to the dorsum of the hand facilitates easy exposure (2).
The dorsal aspect of the wrist is characterized by a loose skin and
subcutaneous tissue. A thin superficial fascia covers the dorsal aspect
of the wrist and hand including fatty and fibrous layers, cutaneous
nerves, and venous and lymphatic vessels. When approaching the wrist
joint, the vessels should be preserved whenever possible to facilitate
venous return from the hand which is largely dependent upon these
cutaneous vessels (3). The dorsal nerves and
subcutaneous veins should be raised in continuity with the skin and
subcutaneous tissues. The dorsal aspect of the hand is supplied by
branches of the superficial branch of the radial nerve and the dorsal
sensory branch of the ulnar nerve in a variable pattern with an
inconsistent contribution of the lateral and posterior antebrachial
cutaneous nerves (5, 6, 7).
These cutaneous nerves should be identified and preserved. Use of
vessel loops to isolate and protect the nerves may be helpful.

The extensor retinaculum is the next deepest structure
encountered. The wrist and finger extensors travel beneath the extensor
retinaculum in six dorsal compartments, delineated by fibrous septae
attaching from the extensor retinaculum to the periosteum of the
radius. Palmer et al investigated the anatomy and biomechanical role of
the extensor retinaculum of the wrist (8). This
fibrous thickening of the antebrachial fascia lies in a band over the
dorsal aspect of the wrist joint and is continuous with the volar
carpal ligament palmarly and the dorsal fascia over the distal hand and
metacarpal region (8). Fibrous septae
traversing from the retinaculum palmarly to insert upon the radial
periosteum or wrist capsule create five fibro-osseous tunnels and one
fibrous canal, the 5th compartment. From radial to ulnar, the
compartments are as follows: first dorsal compartment: abductor
pollicis longus and extensor pollicis brevis; second dorsal
compartment: extensor carpi radialis longus and brevis; third dorsal
compartment: extensor pollicis longus; fourth dorsal compartment:
extensor digitorum communis and extensor indicis proprius; fifth dorsal
compartment: extensor digiti minimi; and sixth dorsal compartment:
extensor carpi ulnaris.

Deep to the extensor tendons lies the capsule of the
wrist joint. The capsule is comprised of ligamentous tissue and
nonligamentous tissues. The major dorsal wrist ligaments are the dorsal
radioulnar ligament, the dorsal radiocarpal ligament, and the dorsal
intercarpal ligament. The dorsal radioulnar ligament spans from the
radius at the dorsal margin of the sigmoid notch over the distal
radioulnar joint (DRUJ) to attach to the head of the ulna and along the
styloid process. It contributes to the extensor carpi ulnaris subsheath
and the triangular fibrocartilaginous complex (TFCC). Similarly, the
dorsoradioulnar ligament attaches to the radius at a site ulnar to the
Lister’s tubercle then spans the radiocarpal joint obliquely to attach
to the dorsal horn of the lunate and to form the lunotriquetral
interosseous ligament superficially. The dorsal intercarpal ligament is
confluent with the dorsal radiocarpal ligament at their insertions upon
the triquetrum. It courses distally and obliquely from the triquetrum
to the dorsal ridge of the distal half of the scaphoid and to the
dorsal cortex of the trapezoid (2). To expose
the dorsal aspect of the wrist, a dorsal capsular flap (the Mayo flap)
can be raised by elevating a split dorsal radiotriquetral and dorsal
intercarpal ligament with a radial based flap.

Dorsal exposure of the wrist joint is useful for
procedures to address pathology of the carpus, the extensor tendons,
the PIN, or fractures. The subcutaneous location makes this approach
readily available and relatively simple. Attention to ligament sparing
capsulotomy can preserve stability and motion in certain cases.

Regional or general anesthesia is routinely used and the
exploration is performed in a bloodless field provided by a tourniquet.
The ulnar nerve can be explored through a volar approach, which is
located 1 to 2 cm more medially than the typical approaches for open
release of the carpal tunnel. A consideration in planning the skin
incision is the location of the palmar cutaneous branch of the ulnar
nerve. Although this nerve was found to be present in only 25% in
previous cadaveric studies (2), injury to it
can lead to painful neuromas. The ideal incision should be located in
the internervous plane between the palmar cutaneous branch of the ulnar
and median nerve. Unfortunately, cadaveric studies have identified that
there is not such a plane. This plane is innervated by the nerve of
Henle (the nerve of the ulnar artery) and multiple ulnar cutaneous
branches (3). Therefore, the dissection of the
skin and subcutaneous tissue should be performed carefully, possibly
under loop magnification, preserving any emerging cutaneous branches.

Anatomic landmarks are the pisiform, the hook of the
hamate, and the hypothenar eminence. The typical incision is
curvilinear in shape with the distal limb following the radial limb of
the hypothenar eminence and the proximal limb extending on the volar
ulnar part of the forearm. The wrist crease should not be crossed
longitudinally but rather in an angle of 60 degrees to avoid skin
contractures. The total length of the incision is about 6 to 8 cm
centered over the wrist crease (Fig. 1-14).

The ulnar nerve and artery can be easily identified in
the proximal part of the incision where they lie on the lateral surface
of the tendon of the FCU (Fig. 1-15).
They can be traced easily distally incising all tissues more
superficial to these structures. The dissection of the subcutaneous fat
should be performed bluntly in order to avoid injury to any cutaneous
branches. The palmaris brevis muscle is elevated slightly ulnarly and
the volar carpal ligament and pisohamate ligament are incised resulting
in a complete decompression of the Guyon’s canal. The two branches of
the ulnar nerve at the level of the pisiform are identified.

The motor branch is more dorsal and more medial at the
level of the bifurcation. It can be traced beneath the fibrous arch of
the hypothenar muscles formed between the abductor digiti minimi and
the flexor digiti minimi, through the muscle mass of the opponens
digiti minimi and around the hook of the hamate. A careful exploration
of the floor of the distal ulnar tunnel is performed looking for any
pathology like ganglions, fibrous bands, anomalous muscle masses,
fractures of the hook of the hamate, and vascular aneurysms.

The tourniquet should be deflated before closure of the
wound and the ulnar artery and its branches should be examined for any
injury. Thorough hemostasis should be achieved since a post-operative
hematoma can result in compression neuropathy of the ulnar nerve.

An alternative surgical approach is through an open
carpal tunnel syndrome incision extending slightly more proximally and
distally. The ulnar nerve and artery are located on the volar medial
surface of the transverse carpal ligament and can be identified tracing
the superficial palmar arch proximally. Several hand surgeons prefer to
decompress the Guyon’s canal and the carpal tunnel simultaneously.

Around the pisiform the ulnar nerve divides into two
branches, the superficial and the deep branch. The superficial branch
gives immediately after the bifurcation motor branches to the palmaris
brevis muscle and becomes purely sensory. It continues its course
distally deep and medial to the ulnar artery providing sensory supply
to the small finger and the ulnar side of the ring finger. The deep
branch of the ulnar nerve bifurcation is purely motor and supplies the
hypothenar muscles, all the interossei, the medial two lumbricals, and
the adductor pollicis. The motor part of the ulnar nerve is located
dorsally in the ulnar nerve at the level of the distal forearm and
emerges from the nerve on the dorsal medial surface. The motor branch
leaves the tunnel and passes beneath the fibrous arch of the hypothenar
muscles and enters the interval between the abductor digiti minimi and
flexor digiti muscles. It pierces the opponens digiti minimi and curves
radially and dorsally around the distal part of the hook of the hamate,
lying on the floor of the carpal tunnel (Fig. 1-16).

Compared to the carpal tunnel syndrome, ulnar tunnel
syndrome is less common because the space within the Guyon’s canal is
much more yielding. Compression within the canal can produce motor or
sensory or combined motor and sensory symptoms. The Guyon’s canal can
be divided in three zones to allow more accurate localization of the
pathology of the compression in respect to the neurological symptoms (4).

Zone I is the most proximal and is bounded palmarly and
radially by the volar carpal ligament, medially by the FCU and the
pisiform, and dorsally by the transverse carpal ligament. This region
includes both the sensory and the motor branches of the ulnar nerve;
therefore, compression in the region results in combined motor and
sensory deficits. Compressions within this region are usually produced
by fractures of the hook of the hamate and ganglions (Fig. 1-17).

Zone II is bounded palmarly by the palmaris brevis
muscle and the fibrous arch of the hypothenar muscles; dorsally by the
pisiform and hamate ligaments and the oppenens digiti minimi; medially
by the superficial branch of the ulnar nerve and the abductor digiti
minimi; and laterally by the transverse carpal ligament, flexor digiti
minimi, and the hook of the hamate. This region surrounds the motor
branch of the ulnar nerve and compression within this region results in
motor symptoms. Ganglions and fractures of the hook of the hamate can
produce compression within this region, as well as anomalous intrinsic
muscles within the canal (Figs. 1-18 and 1-19).

Zone III is bounded palmarly by the ulnar artery and the
palmaris brevis muscle, dorsally by the hypothenar fascia, laterally by
the motor branch of the ulnar nerve, and medially by the abductor
digiti minimi muscle. This region surrounds the superficial branches of
the ulnar nerve, and compression within this region produces
exclusively sensory symptoms (Fig. 1-19).
The most frequent causes of compression within this region are synovial
inflammation, vascular lesions of the ulnar artery (thrombosis,
aneurysm, or pseudoaneurysm), and anomalous size and location of
abductor digiti minimi.

The flexor muscles originate in the proximal two-thirds
and provide the respective flexor tendons in the distal third of the
volar compartment of the forearm. Three flexor tendons insert around
the area of the wrist; the flexor carpi radialis located on the radial
side of the forearm inserts at the base of the second metacarpal; the
FCU located in the ulnar aspect of the forearm inserts at the pisiform
bone; the palmaris longus located in the most superficial layers along
the midline of the forearm inserts at the palmar fascia of the hand.
The palmaris longus is absent unilaterally or bilaterally in 12% and is
useful in grafting because it is readily accessible and expandable.

The remaining nine flexor tendons are the flexor tendons
of the fingers and the thumb; two for each of the fingers and one long
flexor for the thumb. They all enter the hand through the carpal tunnel
and diverge towards the respective digit where they insert.

There are two flexor tendons for each finger, the flexor
digitorum superficialis (FDS) and the flexor digitorum profundus (FDP).
The FDS tendons lie more anterior to the FDP within the forearm and the
palm and are grouped in two layers within the carpal tunnel. The
tendons of the middle and ring fingers lie volarly to those of the
index and small fingers. At the palm all the tendons of the FDS lie in
the same plane, volar to the tendons of the FDP.

The tendons of the FPD are all in the same plane and are
usually not so distinct at the level of the palm with the exception of
the tendon to the index. They become more distinct distal to the carpal
tunnel. An important anatomical relationship helpful in distinguishing
the tendons of the FDP from the FDS in multiple tendon lacerations
within the palm is that the four lumbrical muscles take their origin
from the tendons of the FDP.

At the level of the metacarpophalangeal joint, the FDS
splits into bands. The FDP passes between these two bands becoming more
superficial to the FDS forming the Camper’s chiasm. The two bands of
the FDS rotate away from the midline so that the most medial fibers
become the most volar ones and the most lateral ones become the most
dorsal, and insert at the two lateral edges of the base of the middle
phalanx. The FDP continues more distally and inserts at the base of the
distal phalanx.

The thumb has only one flexor tendon, the flexor
pollicis longus (FPL), which enters the carpal tunnel in its most
radial aspect. Following the carpal tunnel, the tendon courses around
the scaphoid, beneath the thenar musculature, and inserts at the base
of the distal phalanx of the thumb.

The tendons of the FDS and FDP for each finger enter a
well-defined fibro-osseous tunnel just proximal to the respective
metacarpophalangeal joint of the finger. This digital fibrous sheath
consists of thick fibrous bands in oblique or transverse orientation,
known as pulleys, which keep the tendons close to the phalanges and
prevent bowstringing during flexion of the finger. The current
nomenclature for the pulley system was established by Doyle and Blythe (1,2),
who described five annular “A” (A1-A5) and three cruciate “C” (C1-C3)
pulleys. A1, A3 and A5 are located over the metcarpophalangeal,
proximal interphalangeal, and distal interphalangeal respectively. A2
and A4 are located over the middle part of the proximal and distal
phalanx respectively. The C1 pulley is over the distal end of the
proximal phalanx, the C2 pulley over the proximal end of the middle
phalanx, and the C3 pulley over the distal end of the middle phalanx (Fig. 1-20).

The thumb has a similar fibro-osseous tunnel with an
annular A1 pulley over the metacarpophalangeal joint, an oblique
annular ligament extending from proximal ulnar to distal radial
direction over the proximal phalanx of the thumb, and an annular A2
pulley over the interphalangeal joint.

The nutrition of the flexor tendons within the digital
sheath comes from two sources: diffusion and vascular perfusion from
the vincular system. Each tendon has a long and short vinculum, which
are folds of the mesotenon running from the dorsal portion of the
dorsal wall of the tendon sheath, emerging from the digital vessels.
The short vinculae of the FDS and FDP, which are located respectively
over the ends of the proximal and middle phalanges, are considered the
important ones.

The course of the flexor tendons from their origin to the tip of the digits has been classified by Kleinert and Verdan (3)
into five zones, I-V, based on their peculiar anatomy and their
prognosis after primary repair. Zone I represents the region distal to
the insertion of the FDS. Zone II describes the region where the FDS
and the FDP share the fibro-osseous sheath of the digit, from the level
of the metacarpal neck to the middle of the second phalanx. This zone
is also known as the “no man’s land,” a term introduced by Bunnell (4)
to describe the poor earlier results of flexor tendon repairs within
this area. Zone III represents the region between the distal part of
the transverse carpal ligament and Zone II. The tendons under the
transverse carpal ligament are located within Zone IV. Finally, Zone V
represents the most proximal part of the tendons within the region
proximal to the carpal canal in the forearm. A similar zone system has
been described for the thumb flexor tendon (Fig. 1-21).

There are significant differences between the volar and
the dorsal skin of the palm and the fingers. The volar skin is thicker
and tougher to stand wear, and more firmly attached to the underlying
structures. The palmar aponeurosis is a specialized thickening in the
deep fascia located under the palmar skin extending from the level of
the wrist joint to the level of the metacarpal heads. At that level, it
divides into longitudinal fibers which continue into the fingers. Both
the palmar aponeurosis and the longitudinal fibers give off superficial
attachments to the skin resulting in a rather nonmobile skin allowing
little plastic maneuvering. A system of creases, where the skin is
adherent to the deeper layers, allows for closing of the hand without
bunching up in folds.

On each finger there are two flexion creases overlying the proximal interphalangeal joint called proximal digital creases, but only one overlying the distal interphalangeal joint called distal digital crease. A single crease at the base of each finger, the palmar digital crease,
identifies the distal end of the palm and is located over the proximal
third of the proximal phalanx. On the thumb, there is double flexion
crease over the interphalangeal joint called thumb interphalangeal crease and a wider double crease over the metacarpophalangeal joint called proximal thumb crease (Fig. 1-22).

Three distinct skin creases are normally seen in the palm. The proximal palmar or thenar crease designates the limit of thenar eminence and the level of motion of the thumb. The transverse or midpalmar crease
begins at the midpoint of the hypothenar eminence and extends almost to
the radial end of the thenar crease. It signifies the level of the
metacarpal heads of the fingers. The distal palmar crease
is situated distal to the midpalmar crease and runs from the index
middle finger cleft to the ulnar border. It represents the level of
motion of the metacarpophalangeal joints of the ulnar three fingers. A
number of oblique and vertical skin creases of minor clinical
significance exist proximal to the midpalmar crease. Finally, the
distal forearm is separated from the palm with a transverse skin crease
called the wrist crease (Fig. 1-22).

A standard operating table is usually used with the
ability to firmly anchor a hand board or table on its side. Most hand
surgeries can be performed with the patient supine on the operating
table.

Regional anesthesia in the form of supraclavicular,
axillary, brachial, and peripheral nerve blocks can be used in the
majority of the surgical procedures of the hand. In case of
apprehensive adults or children, general anesthesia is usually
preferred. The final choice of the type of anesthesia for each
procedure is made by the anesthesiologist after being presented with
the patient’s and surgeon’s concerns and wishes.

Sterling Bunnell, the father of modern hand surgery,
emphasized the importance of atraumatic surgical technique in
reconstructive hand surgery. He mentioned: “A jeweler can’t repair a
watch in a bottle of ink and neither can we repair a hand in a pool of
blood” (4). A bloodless field achieved with a
tourniquet allows surgical dissection with accuracy and minimal trauma.
The tourniquet pressure should be at least 100 to 150 mm Hg higher than
the systolic blood pressure, reaching about 250 mm Hg in adults and 200
mm Hg in children. Wilgis (5) established that
the safe period of tourniquet inflation is about 2 hours since longer
use may lead to tourniquet palsy. In case there is a need for a longer
period than 2 hours, then the tourniquet should be deflated for 10 to
15 minutes and then reinflated.

Sharp dissection with the aid of magnifying loops or
glasses using small blades and instruments is essential in the
atraumatic technique advocated by Bunnell and other hand surgeons.

There are a great number of skin incisions in the hand
and the fingers. Certain basic principles should be followed at all
instances. The skin incisions should never be placed within deep skin
creases. The subcutaneous fat is very thin under these creases and
moisture tends to accumulate leading to maceration of the skin edges.
The incisions should be long enough to expose the underlying deep
structures without stretching the skin edges, since the mobility of the
volar skin in the hand is limited. The reflected skin edges should be
thick involving the underlying fat in order to avoid devascularization
of the skin edges. The direction of the dissection in the deeper
tissues can follow a different orientation than the direction of the
skin incision.

Straight-line incisions should be avoided; gently curved
or angled incisions provide better exposure and are less noticeable
cosmetically. Furthermore, they can be extended with freer choice of
direction.

The plane of motion of the different parts of the hand
is perpendicular to the long axis of the skin creases. Therefore, an
incision should not cross a crease at or near a right angle since the
resulting scar being in the line of tension during early motion will
hypertrophy resulting in function impairment.

Parallel or nearly parallel incisions should be avoided
because necrosis or delayed healing can occur due to limited blood
supply of the bridged skin flap, especially if the incisions are too
close to each other or too long.

Based on the principles mentioned above there are many
different finger incisions. The most popular are the zigzag incision
and the midlateral incision.

All the principles that apply to the fingers concerning
the skin and the skin creases apply to palmar incisions too. As a
general principle, the incisions in the palm tend to be more transverse
in the distal part and more longitudinal curving radially and parallel
to the closest skin crease in the proximal part. There is a great
variability of skin incisions in the palm, especially in the distal
part.

The most common incisions in the distal part of the palm
are the transverse incisions used in trigger fingers. The location of
these incisions is exactly over the midpalmar crease in most of the
patients, although they may be located slightly more distally in case
of the middle, ring, and small fingers. All these transverse incisions
can be extended more proximally towards the thenar crease keeping in
mind that the flexor tendon course is towards the midline from distal
to proximal as they exit from the carpal tunnel (Fig. 1-29).

After the dissection of skin and subcutaneous fat, the
latter is dissected from the palmar fascia trying to preserve any
perforating small vessels that may supply the more superficial layers.
The palmar fascia is incised in any desired orientation keeping in mind
that the vital structures are under it. If wider exposure is desired,
part of the palmar fascia can be excised. The tendons and the
longitudinally oriented neurovascular bundles can be seen. It is
advisable to always locate the neurovascular bundles at this level and
protect them at all times during the flexor tendon surgical procedure.

Most of the vital structures like arteries or nerves lie
under the palmar fascia in the proximal part of the palm. In the distal
palm, these structures are lying between the metacarpals heads and are
not protected by the palmar fascia. In the very distal part of the palm
the arteries and nerves are oriented longitudinally. In the proximal
part of the palm there are some structures with a transverse
orientation, like the superficial palmar arch and the thenar motor
branch of the median nerve.

The more proximal incision of the palm involves release
of the transverse carpal ligament and will be discussed in conjunction
with the surgical approaches of the flexor tendons in the wrist.

The surgical approach of the flexor tendons in the wrist
involves release of the carpal tunnel and approach of the flexor
tendons in the proximal part of the palm and the distal forearm.

Important landmarks for this approach are the thenar
crease, the transverse skin crease of the wrist, and the tendon of
palmaris longus whenever it is present. The incision is placed just
ulnar to the thenar crease at the level of the Kaplan’s cardinal line,
curving radially proximally, remaining always on the ulnar side until
the level of the wrist crease. At that point, the incision is curved
ulnarly in order to avoid crossing the wrist crease transversely and
continues along the midline of the forearm (Fig. 1-30A).

The skin incision starts proximally in the palm where
the skin flaps should be incised carefully. The palmar cutaneous branch
of the median nerve lies superficially between the flexor carpi
radialis and the median nerve and enters the palm in a variable course.
Dissection of the subcutaneous fat should be performed carefully,
trying to identify and protect branches of this nerve. After incision
of the subcutaneous fat, the tendon of the palmaris longus is visible
proximally and its insertion, the fibers of the palmar fascia, is
visible distally. The fibers of the palmar fascia should be incised
longitudinally along the line of the skin incision. The tendon of the
palmaris longus inserting in these fibers should be retracted ulnarly.
The median nerve is located under the tendon of the palmaris longus
between the palmaris longus and the tendon of the flexor carpi
radialis. The muscle fibers of the palmaris brevis muscle are located
under the palmar fascia and are incised longitudinally. The fibers of
the transverse carpal ligament are visible with their most proximal
part located at the level of the transverse wrist crease. A blunt
spatula-like instrument is placed between the median nerve and the
transverse carpal ligament. Careful incision of the fibers cutting on
the instrument to avoid any injury to the median nerve is performed. It
is advisable to transect the fibers on the ulnar side of the median
nerve to avoid injury to the motor branch to the thenar muscles. The
flexor tendons are visible around the median nerve within the carpal
tunnel and in the distal forearm. The tendons of the FDS, FDP, and FPL
are directly accessible along this incision. The flexor carpi radialis
and the FCU are located at the most ulnar and radial parts of the
incision at the level of the distal third of the forearm.

Besides the palmar cutaneous branch of the median nerve,
several dangers exist in this extended approach of the flexor tendons
in the wrist. The superficial palmar arch lies exactly over the tendons
at the exit of the carpal tunnel and proximal extension should be
performed cautiously. The motor branch of the median nerve usually
emerges from the radial part of the nerve either distal or under to the
transverse carpal ligament. There are few cases where the motor branch
arises within the carpal tunnel and pierces the transverse carpal
ligament posing a possible danger during the release of the carpal
tunnel. In the most proximal part of the incision, the ulnar nerve and
artery, the median nerve, and the radial artery are located between the
flexor tendons and should be protected during dissection.

Several variations exist for the most proximal part of
the incision. Instead of a proximal midline extension in the distal
forearm, an ulnar longitudinal incision can be performed (Fig. 1-30B).
An advantage of this alternative approach is that the incision is not
performed exactly over the median nerve providing a well vascularized
skin flap over the nerve. A similar radial longitudinal incision should
be avoided because it places the palmar cutaneous branch of the median
nerve at risk.

Skin lacerations with flexor tendon lacerations are very
common clinical situations. In these cases, the previously mentioned
surgical approaches have to be modified in order to incorporate the
skin lacerations. As a general principle, the skin laceration can be
extended proximally or distally using the Brunner zigzag approach (Fig. 1-31).
Adequate surgical exposure is needed to identify and expose the tendon
ends. Lacerated flexor tendons retract frequently in the palm unless
there is intact vinculum or lumbrical muscle preventing further
proximal retraction. The proximal end of the tendon may retract so much
that a wide exposure is needed. Another alternative is to perform an
independent proximal surgical exposure and retrieve the tendon at that
point and retract it to the more distal surgical approach under the
intact skin bridge. Such incisions can be performed in the palm at the
level of the distal palmar crease. In case of FPL laceration at the
base of the thumb, the proximal part of the tendon usually retracts
under the thenar musculature or even in the palm. An isolated radial
longitudinal incision may be necessary to retrieve the tendon in the
palm and retract it to the thumb.

The skin wounds should be closed early, but not
necessarily immediately, to lessen the chance of a wound infection.
Whenever there is tendon, bone, or neurovascular structure exposed
immediate coverage is essential. Primary skin closure is preferable if
it can be achieved without tension; otherwise some type of skin
grafting is preferable.

The use of the dorsal radial exposure of the scaphoid is
most commonly employed in the setting of an acute proximal pole
scaphoid fracture; however, surgical exposure and internal fixation of
the scaphoid may also be indicated for (a) any displaced scaphoid
fracture; (b) scaphoid fractures with significant bone loss; (c)
fractures with angulation or rotation; or (d) scaphoid fractures
resulting in loss of the lateral intrascaphoid angle, fracture
dislocations of the scaphoid and greater arc injuries (1, 2, 3, 4, 5, 6, 7).
In addition, any scaphoid fracture which results in loss of carpal
alignment or which cannot be satisfactorily corrected or maintained by
manipulation and casting should be treated by operative reduction and
internal fixation (8).

The scaphoid may be exposed through a palmar or dorsal
approach. The palmar approach has been classically used for the
treatment of waist fractures and for the repair of nonunions (9).
A dorsal longitudinal approach to the wrist may also be used for
scaphoid exposure in cases of pan-carpal injury or in cases involving
concomitant distal radius fractures. When the scaphoid alone is
fractured one may utilize a dorsal radial exposure.
The dorsal radial approach to the scaphoid allows for exposure of the
proximal pole of the scaphoid, the dorsal mid waist, the
scapho-trapezial-trapezoid joint as well as the dorsal portion of
scapholunate interosseous ligament. The dorsal radial approach may be
used for cases of scaphoid non-union and allows for the utilization of
vascularized bone grafts from the dorsal distal radius (Fig. 1-43).
The dorsal radial exposure has the benefits of not violating the palmar
supporting ligaments of the wrist and preserves the palmar blood supply
to the scaphoid (1,10,11). The dorsal radial exposure may place the superficial branch of the radial nerve at risk (Fig. 1-44).
This approach provides only minimal exposure of the lunate and allows
for no visualization of the ulnar aspect of the wrist, because of this
the dorsal radial approach should not be used for the evaluation or
treatment of lesser or greater arc injury patterns, or in cases where
significant collapse is present within the scaphoid.

1. Incision: the exposure begins with a 3 to 4 cm
incision beginning over Lister’s tubercle and extending distally along
the line of extensor pollicis longus (EPL) (Fig. 1-45).

2. A dorsal longitudinal approach to the wrist may also
be used for scaphoid exposure in cases of pan-carpal injury or with
concomitant distal radius fractures and intercarpal or radiocarpal
arthrodesis. Subcutaneous dissection is carried out to identify the
branches of the radial nerve, passing over the 2nd compartment, which
are retracted radially.

3. The 2nd and 3rd extensor compartments are opened and the EPL is mobilized towards the base of the thumb (Fig. 1-46).

4. The ECRL and ECRB and EPL are the retracted radially (Fig. 1-47).
If necessary the EPL may be released entirely from its compartment and
transposed radial to Lister’s tubercle to facilitate retraction.
Mobilization of the EPL also allows for identification of the posterior
interosseus

nerve running on the ulnar side of Lister’s tubercle which may be excised for partial wrist denervation.

5. The wrist capsule is incised in line with the fibers
of the dorsal intercarpal ligament, with a straight axial cut, or a “T”
shaped incision (Fig. 1-48) (13).

6. Following capsulotomy, the scaphoid and the dorsal
portion of the scapholunate ligament is inspected. Loose fragments of
articular cartilage, loose bodies, synovitis, and hemarthrosis may need
to be removed to improve visualization. The proximal pole may be
further evaluated by flexing and radially deviating the wrist.

Potential complications from the surgical exposure are
few and may include injury to the radial sensory nerve branch, tendon
injury to the 2nd or 3rd compartment tendons, and post-operative
extensor tendon adhesions. Hypertrophic scarring and wound infection
may also occur. The dorsal radial exposure is not ideal for
scapholunate or perilunate fracture dislocations, where exposure of the
lunate is important for adequate reduction. In addition, this exposure
limits access to the dorsal capsule if formal dorsal capsulodesis is to
be performed for cases of static scapholunate instability. Also this
approach may be inadequate for restoring scaphoid height in cases of
scaphoid malunion or nonunions exhibiting significant humpback
deformity. In such cases we have found that the volar approach allows
for easier cortical graft placement and facilitates correction of
scaphoid alignment.

The blood supply to the scaphoid is theoretically at
risk with the dorsal radial approach and one must be wary not to injury
the vessels entering at the radial dorsal crest during fracture
exposure. Overall, however, the dorsal radial approach provides ample
and easy access to the scaphoid for most cases of acute fracture and
non-union.