ARTHRODESIS OF THE HAND AND WRIST

Osteoarthritis commonly affects the distal
interphalangeal (DIP) joints of the fingers and, to a lesser extent,
the interphalangeal (IP) joint of the thumb. Other diseases that less
commonly affect the DIP joints are psoriatic arthritis, rheumatoid
arthritis, and infection. In all these diseases, hand function is
limited by painful motion of the joints. Arthrodesis of the DIP joint
is a successful way to eliminate the pain associated with these
disorders.

The proximal interphalangeal (PIP) joints are more
commonly involved in rheumatoid arthritis as well as osteoarthritis.
Posttraumatic arthrosis of a single PIP joint is a common problem. The
disability for the rheumatoid patient is the associated swan-neck or
boutonnieére deformity, while for the posttraumatic arthritic patient
it is usually pain. Arthrodesis of the PIP joints is a reliable method
of returning function to these fingers, and it is especially
appropriate for the index and small fingers because of their unique
position as border digits.

Metacarpophalangeal (MCP) joints may be affected in
multiple fingers in rheumatoid arthritis, or singly in posttraumatic
arthritis. Arthroplasty is usually preferred for the MCP joints of the
fingers to preserve good motion and function. Arthrodesis is useful for
joints when arthroplasty is not indicated, or when a previous
arthroplasty has failed.

Carpometacarpal arthrodesis, although less commonly
performed, can also improve functional outcomes, particularly in the
fourth and fifth carpometacarpal joints, which may have osteoarthrosis
as a late sequela of fracture dislocations (15,17). Elimination of pain and increased stability improves hand function.

The thumb interphalangeal (IP) joint is not unlike the
IP joints of the digits. It is important for stable power pinch, which
may be compromised in osteoarthritis because of pain or connective
tissue disease caused by joint laxity.

The thumb MCP joint is different from the other MCP
joints in that significantly more stress is placed on the ligamentous
restraints than in the finger joints. This is because of the unique
position of the thumb and its role in pinch and grasp. Instability of
this joint is common because of chronic laxity after a missed acute
tear of the ulnar collateral ligament (gamekeeper’s thumb) and
rheumatoid arthritis (19,48).
While ligament reconstruction and soft-tissue procedures are usually
preferred, in the arthritic thumb MCP joint, arthrodesis (Fig. 72.1, Fig. 72.2) provides a more lasting option and is generally preferred to arthroplastic techniques for a number of different disorders (36).

In the thumb, the joint most commonly affected with osteoarthritis is the carpometacarpal (CMC) joint (6).
This is perhaps the most commonly involved joint in postmenopausal
women with early osteoarthritis. It has been postulated to be secondary
to laxity of the metacarpal volar beak ligament, allowing enough
subluxation and incongruity of the joint to become pathologic. A second
commonly affected group is young people with high demands on their
hands (e.g., manual laborers) who have posttraumatic arthritis after an
old intraarticular fracture of the base of the metacarpal (Bennett’s or
Rolando’s fracture). Eaton et al. (28a) have
classified this pattern of osteoarthrosis of the first CMC joint into
four stages. Stage I has normal intraarticular cartilage with
joint-space widening. In stage II, there is narrowing of the joint
space but the articular contours are normal. Stage III disease has

significant
destruction of the thumb CMC joint, but the scaphotrapeziotrapezoidal
(STT) joint is normal. In stage IV disease, there is destruction of the
STT joint in addition to the first CMC joint. Arthrodesis of the thumb
CMC joint is indicated for stage III disease but is contraindicated in
the presence of any scaphotrapeziotrapezoidal disease (stage IV).

Patients who benefit most from an arthrodesis of the
thumb CMC joint are usually young, active people who require a strong,
stable, pain-free thumb to perform work activities (6,20). House et al. (43) found that arthrodesis of the first CMC improved hand function in patients with tetraplegia following spinal cord injury (see Chapter 68).
Arthrodesis is the best salvage procedure for failed arthroplasty or
previous infection of the first CMC joint. Older patients and patients
whose demands for strength of pinch and grip are not high are better
served with an arthroplasty (see Chapter 70). Moore et al. (72)
reported successful use of arthrodesis for a rare problem, laxity of
the thumb CMC joint in patients with Ehlers-Danlos syndrome. Thumb CMC
arthrodesis significantly limits thumb motion, although some
compensatory motion occurs at the STT and the MCP joints; therefore, in
patients who require motion of the thumb, arthrodesis is
contraindicated.

A patient who has disease throughout the small joints of
the hand will generally be better served with an arthroplasty of the
finger MCP joints and arthrodeses of the PIP and DIP joints. The
position for arthrodesis in the fingers is critical to hand function.
In general, there should be a gentle cascade from radial to ulnar with
more flexion of the ulnar digits, as can be appreciated in the normal
hand at rest.

Successful arthrodesis of a small joint in the hand requires careful preparation of the bone surfaces of the joint (15,48). Excellent cancellous-to-cancellous bone contact gives the best chance for fusion.

Many techniques to stabilize small-joint arthrodeses
have been used, and multiple studies have described consistent success
using different techniques (5,9,12,15,16,17,19,20,27,31,36,45,48,49 and 50,54,55,58,66,67,74,82,83,85,86,88,89,93,96,102,103,107).
They differ with regard to the degree of difficulty of using the
instrumentation, whether bone grafts are harvested from other surgical
sites, and technical difficulty.

In a biomechanical study, Kovach et al. (54)
compared crossed K-wires, tension band wiring, and an interosseous loop
supplemented by a K-wire in a PIP arthrodesis model. Tension band
wiring was found to be the strongest. In a

comparison
study of four methods of fixation for CMC arthrodesis using crossed
K-wires, cerclage wiring, and cup and cone with single K-wire and
tension band wiring, Stokel et al. (86) found that tension band wire and cerclage techniques provided the most stable construct. Bamberger et al. (6) have used the cup and cone method originally described by Carroll and Hill (19)
with staple or K-wire fixation. They found a 42% delayed union/nonunion
rate for the staple method compared to an 11% rate of delayed union for
the K-wire group.

The scaphoid is unique in that it spans both the
proximal and the distal carpal rows. Because of its unusual anatomy,
deformity of the wrist follows well-delineated patterns when the
scaphoid or its ligamentous restraints are injured (see Chapter 41 and Chapter 42).
One of these patterns, the scapholunate advanced collapse (SLAC)
pattern of wrist arthritis, accounted for 57% of degenerative wrist
arthritis when Watson and Ballet (98) reviewed
4,000 radiographs. These authors also reported primary triscaphe joint
arthritis in 27% of these patients and a combination of both in 15% of
patients. The primary disorder in the SLAC wrist is that of
scapholunate dissociation secondary to scapholunate interosseous
ligament rupture (3). This allows for unopposed volar flexion of the scaphoid and the dorsal intercalated segmental instability (DISI) pattern (26).
Lateral radiographs may show the scapholunate angle to be increased
beyond 60°, which is felt to be the upper limit of normal. On an
anteroposterior (AP) radiograph, the scaphoid appears foreshortened,
has a “cortical ring” sign and there is a scapholunate gap of greater
than 3 mm.

The SLAC pattern of arthritis begins in its earliest
stage, stage 1 arthritis, with destruction of the distal aspect of the
radioscaphoid joint (2). This is caused by the
incongruity between the scaphoid and the scaphoid facet of the radius
when the scaphoid is extremely volar flexed. In stage 2, the entire
radioscaphoid joint is arthritic. Stage 3 is characterized by further
separation between the scaphoid and the lunate, allowing the capitate
to migrate proximally. When this occurs, the SC and capitolunate joints
become arthritic. Stage 4, in which the radiolunate joint becomes
arthritic, is rarely seen because the spherical shape of the proximal
lunate and the lunate fossa of the radius make incongruity unlikely
except in the most severe cases.

A nonunion of a fracture of the scaphoid also leads to a
predictable pattern of wrist arthritis when not treated. Because of its
similarity to the SLAC pattern in both progression and treatment, it
has been called the scaphoid nonunion advanced collapse (SNAC) pattern.
In it, volar flexion of the distal pole of the scaphoid leads to
radioscaphoid arthritis (101). The proximal
pole, restrained by the scapholunate interosseous ligament, remains in
normal alignment with the lunate. Given the dissociation between the
proximal and distal rows as a result of the nonunion, a DISI pattern of
deformity results. If left untreated, the

wrist will undergo the same degenerative pattern seen in a SLAC wrist.

Treatment of these two similar disorders has been mainly proximal row carpectomy (46) or scaphoid excision (52) and lunate-capitate-hamate-triquetral (four-corner) arthrodesis (Fig. 72.9 and Fig. 72.10). Although it is not yet clear whether proximal row carpectomy or four-corner fusion provides better results (106)
for stage 2 or 3 SLAC/SNAC disease, it is clear is that scaphoid
excision and four-corner fusion are preferred to proximal row
carpectomy when the capitate head is arthritic.

With this procedure, pain relief and resolution of
symptoms are predictable. In patients with stage 2 or 3 SLAC/SNAC
disease, when strength is important and the patient’s activities do not
require a full range of wrist motion, we perform scaphoid excision and
four-corner fusion, as described later.

Another common problem in the wrist is isolated STT
arthritis. The pain associated with this disorder can be surprisingly
debilitating. The disability associated with STT arthritis can be best
appreciated in activities that axially load the thumb (e.g., strong
pinch, key turning). Watson et al. (99)
attributed rotatory subluxation of the scaphoid as a possible cause of
isolated STT arthritis. They noted early degenerative changes in these
joints when performing rotary subluxation of the scaphoid (RSS
surgery). For isolated STT arthritis, STT arthrodesis has been found to
give good function and excellent pain relief and is preferred by other
authors (53,97).

A less common but equally disabling degenerative pattern
of arthritis in the wrist occurs between the lunate and the triquetrum (24,42,51).
This pattern of arthritis is most probably a result of a chronic
lunotriquetal ligament tear that has not healed. Patients typically
have the radiographic findings associated with volar intercalated
segmental instability (VISI). The scapholunate angle on a lateral
radiograph is less than 30°, the lower limit of normal. This indicates
that the ligamentous complex between the lunate and the triquetrum is
disrupted, allowing the lunate to volar-flex and align with the
scaphoid. Another cause of isolated LT arthritis is incomplete carpal
coalition of the lunate and triquetrum (1).

Degenerative wrist disease evolves when scaphoid
nonunion is left untreated, and in the SLAC wrist deformity. Watson and
Weinzweig (101) described the use of STT
arthrodeses to manage scaphoid nonunion for three specific indications:
scaphoid fractures with a very small proximal fragment, a distal
scaphoid nonunion causing malalignment of the triscaphe joint, and
scaphoid fracture in association with scapholunate dissociation. With
small scaphoid proximal fragments, Watson prefers a dorsal approach
with bone grafting of the nonunion, with a simultaneous triscaphe
arthrodesis. STT arthrodesis is used in distal scaphoid nonunions to
improve alignment in the STT joint. Scapholunate dissociation may be
treated by intercarpal arthrodesis when it is associated with scaphoid
fracture.

A detailed description of carpal instability can be found in Chapter 41. Instabilities result from a wide range of injuries that are either static or dynamic (24,65).
Static instabilities have malalignments seen on standard radiographs.
Dynamic instabilities may appear normally aligned on standard
radiographs but are often exhibited on stress views or other special
projections. Acute injuries (up to 1 week old) have the maximum
potential to go on to primary healing of the ligaments. Subacute
injuries (1–6 weeks old) still can heal and do not display fixed
deformity or arthrosis. Chronic injuries older than 6 weeks have the
least potential for healing, may have fixed deformities or

arthrosis,
and often require surgical repair and reconstruction. It is apparent
that early detection is most important. The position of the lunate as
seen on lateral radiographs is one of the key elements used to
determine loss of normal carpal alignment. The terms dorsal intercalated segmental instability and volar intercalated segmental instability describe the malaligned dorsal or volar tilted lunate of unstable wrists (61).
Although many instability classifications have been proposed, none have
gained universal acceptance, which underscores the complexities of
these injuries and the lack of our present comprehension of this
subject.

The effects of intercarpal arthrodesis on wrist
kinematics is not well understood. When choosing the surgical
procedure, consider the amount of wrist motion that will remain and to
what extent compensatory increases in wrist motion will occur over
time. Although the proximal and distal rows function separately, an
intercarpal arthrodesis that links these rows will have long-term
effects on wrist motion and on radiocarpal and ulnocarpal loading that
could lead to degenerative arthritis in the long term. Gellman et al. (35)
showed that fusion within a carpal row has minimal effect on wrist
motion in all planes. Their study demonstrated that two thirds of
flexion occurs at the radiocarpal joint and one third occurs at the
mid-carpal joint. It also showed that capitolunate fusion caused the
greatest loss of motion in a flexion/extension arc, with STT fusion
causing the greatest loss of motion in the radioulnar plane.

Garcia-Elias et al. (34) studied
the effects of intercarpal arthrodeses on wrist range of motion. They
showed that STT fusions had a greater loss of flexion than SC fusion,
which resulted in a greater loss of extension and radial deviation.
Shear stress was noted to be increased at the radiolunate joint. Viegas
et al. (95) reported that STT and SC fusions
decrease axial load through the radioscaphoid fossa, while
scapholunocapitate and capitolunate fusions distribute load through
both the radioscaphoid and radiolunate fossae.

Watson and Weinzweig (101) have outlined three major principles that apply to limited wrist arthrodesis:

Adherence to these principles is important. STT
(triscaphe) fusion results in a single bony unit that preserves the
external dimensions of these three carpal bones. Current indications
for STT fusion are STT arthrosis, Kienböck’s disease, and carpal
instability, including static or dynamic rotary subluxation of the
scaphoid.

Indications for scaphocapitate (SC) fusion include
rotary subluxation of the scaphoid and scaphoid instability, resistant
scaphoid nonunion, and Kienböck’s disease.

A SLAC wrist reconstruction along with excision of the
scaphoid is an excellent method to treat radioscaphoid degenerative
arthritis and chronic nonunion of the scaphoid, as well as advanced
destruction from scapholunate dissociation or idiopathic avascular
necrosis of the scaphoid.

Lunotriquetral (LT) arthrodesis is indicated in patients with LT instability, LT arthrosis, or LT ligament disruption.

Perform surgery with preoperative intravenous
antibiotics and axillary block or general anesthesia. All patients with
connective tissue diseases or in whom there is concern of cervical
spine instability are prescreened with cervical spine radiographs.
Perform all surgery under tourniquet control, through a dorsal
longitudinal skin approach to the extensor retinaculum.

We prefer a modification of techniques originally proposed by Clayton and Ferlic (21), Mannerfelt and Malmsten (64), and Millender and Nalebuff (68), as follows.

When performing radiocarpal arthrodesis for indications
other than rheumatoid arthritis, we prefer to use the AO method of
plate fixation popularized by Hastings (39) and others (81) (Fig. 72.12 and Fig. 72.13).
Most commonly, the indication for this type of arthrodesis is
posttraumatic arthritis of the wrist or failed wrist arthroplasty.