NONUNIONS AND MALUNIONS OF THE UPPER EXTREMITY

Because the scapula is totally enclosed in an envelope
of heavy muscles and lies on the posterior aspect of the thoracic cage,
fractures that progress to symptomatic nonunion or malunion are
exceedingly rare. Personally, I have never had to treat surgically
either a nonunion or a malunion of the scapula. There are reports of
nonunions of the base of the coracoid process, the scapular body and
spine, and the acromion (2,21,33,52,55,105). Gupta et al. (33)
reported successful treatment of a nonunion of the inferior third of
the body of the scapula (the only case reported in the literature) with
plate fixation and bone graft, resulting in dramatic improvement in
function and relief of pain.

The epiphysis of the acromion is one of the last to
unite and occasionally does not unite, remaining as an os acromiale.
This should not be mistaken for a nonunion. True nonunions, if
displaced inferiorly, can interfere with motion and cause impingement
on the rotator cuff tendons. If symptoms justify, a small fragment can
be excised. Reattachment of the deltoid must be solid and protected
until healed to avoid deltoid deficiency. Excision of any substantial
part of the acromion can lead to permanent deltoid weakness, and
therefore, nonunions producing large fragments deserve repair. Repair
can be challenging because of the thin cortical bone of the acromion,
in which it is difficult to obtain secure fixation. Dounchis et al. (21)
reported successful treatment of a nonunion of a fracture at the base
of the acromion with plate and screw fixation combined with a tension
band wire construct and autologous bone graft.

Nonunions of the coracoid process are more likely to be
secondary to an osteotomy performed for reconstructive shoulder surgery
as opposed to a fracture. If the nonunion is symptomatic, most can be
successfully treated with freshening of the fracture site and internal
fixation with a compression screw. Excision is also possible with
reattachment of the muscles originating from the coracoid to
surrounding soft-tissue structures.

Although the clavicle is probably the most commonly fractured bone, nonunions are rare (82). The incidence of nonunion in clavicle fractures managed nonoperatively is between 0.1% and 1.9% (16,41,68,109). In those managed operatively, the incidence is higher, particularly with intramedullary fixation (91). Functionally disabling malunions are probably even rarer. In the series of 33 patients reported by Wilkins and Johnston (106), nonunion appeared to be more common after refracture or when associated with severe trauma (108).
Patients with atrophic nonunions seemed to have fewer symptoms than
those with hypertrophic pseudarthroses. Atrophic nonunions seem to be
much more common than hypertrophic nonunions (39).

A nonunion of the clavicle in an adult is defined as an
ununited fracture at least 16 weeks after injury. The anatomic location
of the fracture affects the union rates; distal clavicular fractures
have a higher rate of nonunion than middle-third fractures. A
displaced, interligamentous distal-third fracture (Neer type II), in
which the proximal fragment is detached from the coracoclavicular
ligament, is unstable and has a higher nonunion rate (68,69,72).

Malunion of a clavicle is rarely a functional or
clinically significant problem. Most clavicles heal in a malunited
position, because they are usually treated in a figure-eight sling,
which does not provide adequate enough immobilization to ensure
anatomic position (see Chapter 15). It is very uncommon to require any form of treatment for a malunion of the clavicle, except for a cosmetic deformity (69).
Occasionally, brachial plexus impingement can occur when there is
abundant callus. Shortening of more than 15 mm can produce shoulder
discomfort.

Fractures of the proximal humerus account for 4% to 5% of fractures and occur most frequently in the elderly (40).
Failure of this fracture to unite within 6 to 8 weeks constitutes a
delayed union. At 12 weeks, an unstable fracture with no evidence of
callus formation is unlikely to heal. Therefore, operative treatment is
usually indicated. Nonunion of the surgical neck of the humerus is rare
(93). Displaced fractures that remain unreduced
owing to muscle forces, interposed deltoid or biceps, or treatment
producing distraction may result in nonunion. In Neer’s series (70,71),
nonunions were more commonly associated with hanging casts or skeletal
traction and displaced four-part fractures. The incidence of proximal
humerus fractures in women is twice that in men. Osteoporosis and a
short proximal fragment covered for the most part by articular
cartilage makes treatment difficult (Fig. 27.6) (35).
Therapeutic alternatives include symptomatic treatment only, open
reduction, and internal fixation combined with a bone graft or
prosthetic replacement. Because of the challenge of obtaining fixation
in the proximal articular fragment, many different approaches have been
used, including simple plate and screw fixation, double plate fixation,
multiple stiff and malleable wires, Rush rods or Ender pins combined
with malleable wires in a figure eight, and various types of blade
plates or specially designed reconstruction plates for the proximal
humerus (30,34,40,48,100).
In elderly and in middle-aged adults with severe avascular necrosis of
the humeral head, a reasonable alternative is prosthetic replacement of
the proximal humerus. Because the nonunion is typically through the
surgical neck, restoration of the insertion of the rotator cuff is
important. If there is coexisting osteoarthritis of the shoulder joint,
consider total shoulder replacement. In young patients who require a
stable pain-free shoulder for heavy labor, consider arthrodesis (see Chapter 103) (Fig. 27.7).

Isolated fractures of the tuberosities leading to
nonunion are usually accompanied by major ruptures in the rotator cuff.
The most likely avulsion fracture to progress to nonunion is one
involving the posterolateral aspect of the greater tuberosity,
involving the insertions of the infraspinatus and teres minor. On an
anteroposterior (AP) view, these tend to be visualized posterior to the
humeral head and, therefore, are easily missed. The major focus in
repair of these is reconstruction of the rotator cuff, which is
described in Chapter 79. Fixation of the
tuberosity is usually best accomplished by placing it back into its bed
and securing it with multiple figure-eight or horizontal nonabsorbable
sutures interwoven through the insertion of the rotator cuff and the
proximal fragment, and tied through drill holes in the proximal shaft
of the humerus. Screws and other metallic fasteners usually fail
because the avulsed fragment is a thin cortical shell and is usually
full of multiple cracks.

Before the current functional methods of treatment, nonunion rates were as high as 30% for humeral fractures (42,72). With functional bracing, union can now be achieved in 92% to 95% of these fractures (72,88).
Nonunion has been associated with inadequate immobilization,
distraction of the fracture, soft-tissue interposition (particularly at
the deltoid tubercle), and use of inappropriate nonrigid internal
fixation (24,29). A
fracture that is mobile and shows no evidence of callus at 12 weeks is
unlikely to heal, particularly if a gap can be seen on radiographs (13,43).
Hypertrophic delayed unions may be worth treating nonoperatively until
6 months, but I tend to intervene soon after 12 weeks to prevent
long-term permanent joint stiffness from prolonged immobilization. As
with nonunions in the proximal humerus, nonunions in the diaphysis are
frequently challenging. Esterhai et al. (26)
found that, in 46 nonunions, 62% were in elderly patients who were
senile and had disuse osteoporosis. Forty-two percent were synovial
pseudoarthroses; 20% were obese; and 5% had osteomyelitis. Of the
patients they elected to treat with electrical stimulation, only 46%
healed despite the fact that their group is the most expert in the
world in electrical stimulation. For that reason, I do not believe that
electrical stimulation is worth using in nonunions of the humerus
unless it is a hypertrophic nonunion, proven by computed tomographic
(CT) scan and bone scan not to be a synovial pseudoarthrosis. It must
be well immobilized. Internal fixation is best for most patients, but
consider electrical stimulation for patients in whom surgery is
contraindicated or risky.

Malunion of the humeral diaphysis is rarely a functional
or cosmetic problem. The soft-tissue coverage of the arm can obscure up
to 20° of anterior or posterior angulation and up to 30° of varus.
Shortening of as much as 2.5 cm does not lead to disability, and
rotational malalignment can easily be compensated through the shoulder (24).

Nonunions of the distal humerus can be classified as
nonarticular (that is, supracondylar) or intraarticular (usually
involving the lateral condyle, but involvement of the medial condyle is
possible as well) (56). Nonunions in this
region are exceedingly rare, because acute fractures about the elbow
make up only 2% of all fractures and the cancellous bone in this region
usually leads to union. Malunion is more common. Ackerman and Jupiter (1)
treated only 20 patients with nonunions of the distal humerus during a
16-year period at a major referral center. A general orthopaedic
surgeon may encounter only one of these nonunions in his or her career.
Patients treated nonoperatively and those with neglected fractures
frequently have considerable stiffness in the elbow joint and use the
nonunion as a false joint to gain additional motion at the elbow.
Knowledge of the available range of motion in the elbow is essential
for preoperative planning. Lateral radiographs of the elbow joint in
flexion and extension and the distal humerus usually demonstrate the
true range of motion in the elbow and the instability in the fracture.
In supracondylar nonunions, the cartilage of the joint is usually well
preserved; therefore, a comprehensive soft-tissue release to regain
elbow motion not only greatly enhances function but makes it more
likely that the nonunion will heal by relieving stress on the nonunion
site through the increased motion of the elbow joint. Previously open
supracondylar fractures with nonunion, such as in side-swipe injuries,
may have occurred because of bone loss. In a neglected nonunion that is
functioning as the elbow joint, mechanical erosion of the bone ends
frequently leads to shortening and loss of bone substance (Fig. 27.10 and Fig. 27.11). Reconstruction

of these injuries can be difficult owing to the short articular
fragment and the differential in size between the articular fragment
and the shaft. Although the risk of failure is somewhat higher, use of
a structural intercalary bone graft is sometimes necessary to
reconstruct these difficult nonunions, as illustrated in Figure 27.11.

Intraarticular nonunions are exceedingly rare and occur
most commonly in the lateral condyle of the humerus. More commonly,
fractures of the lateral condyle heal in malposition with cubitus
valgus and continue to function fairly well throughout life. Patients
with symptoms that require surgery usually present with tardy ulnar
nerve palsy, decreased range of motion, and pain and apprehension with
use of the elbow (53). Sometimes, corrective
osteotomy must be performed at the time of repair of the nonunion to
improve position using a tricortical graft in the nonunion site (53). Intraarticular debridement and release and balancing of the soft tissues may be necessary to improve or maintain motion.

Nonunion of the olecranon is usually due to neglect of
the original fracture (such as in alcoholics who fail to seek
treatment) or failed internal fixation (usually a tension band wire),
or is secondary to major bone loss such as in side-swipe injuries.
Neglected nonunions can do surprisingly well. They generally are free
of pain with a 2- to 4-cm gap, and the only functional deficit is
weakness in extension, which causes functional limitations but is
compatible with light activities of daily living. In my experience,
failure of internal fixation is most common when lightweight wires are
used to fashion a tension band repair that is then subjected to
repetitive heavy use by an uncooperative patient. It also occurs in
patients who have been victims of multiple trauma, are on enforced bed
rest, and tend to use their elbows for moving themselves in bed.
Failure tends to occur early before these become established nonunions
and can usually be treated by repeated internal fixation with stronger
devices. Nonunions due to bone loss are much more challenging because
they often involve a segment of the articular surface. Indications for
surgery include pain and functional loss. Alternative methods of
treatment in addition to bone graft include compression-plate fixation
with a 3.5 reconstruction plate placed on either the medial or lateral
surfaces of the olecranon and ulnar shaft; tension band plating with a
hook plate, as illustrated in Figure 27.12; or repeat tension band wiring, using a combination of screws and 18-gauge wire for the tension band.

This is an exceedingly rare nonunion; I was able to identify only one reported case of bilateral radial neck nonunion (58).
This was treated with an inlay cancellous iliac crest bone graft,
followed by long-arm cast immobilization for 4 weeks, resulting in
radiographic union by 10 weeks. Surprisingly, full pronation and
supination returned.

Open reduction and plate fixation of displaced fractures
of the diaphysis of the radius and ulna, whether both or only one is
involved, has generally been considered mandatory in adults (3,7,10,14,20,31,36,37,44,46,65,67,76,85,86,94,95,97).
Nearly anatomic reduction and early motion are necessary to avoid
restriction of pronation and supination. Although the ulna may be
treated with a closed reduction and functional bracing (87), plate fixation of the ulna and, on occasion, intramedullary nailing are necessary in significantly displaced fractures.

Current union rates for internally fixed forearm
fractures are 98% or better, with good to excellent functional results
and less than 30% loss of total pronation and supination (3,10,14,20,31,43,80). At least six to eight cortices of fixation, with a 3.5 mm system and compression techniques, should be used (65,94).
Nonunions of the fractures of the shafts of the radius and ulna are now
most commonly due to segmental bone loss, infection, or inadequate
internal fixation with mechanical failure. Poor surgical technique with
excessive soft-tissue striping can also lead to nonunion because of the
devascularization of the bone ends (61,62).

Malunions in the forearm resulting in loss of forearm motion or rotation can be related to fixation of the radius in

malposition; loss of the normal arc and spacing between the radius and
ulna due to collapse of the bones toward the interosseous membrane; or
to subluxation or internal derangements in the proximal radioulnar
joint or the distal radioulnar joint. The latter problems in the joints
are addressed in Chapter 43.
It can be corrected by osteotomy to place forearm motion in a more
functional range. It is difficult to increase the total range of motion
because of intraosseous membrane contraction and soft-tissue scarring.

With increased dissection through the soft tissue,
cross-unions may occur. Rotational problems are best managed at the
time of acute fracture care. Radioulnar synostosis (3,5,50)
may follow closed or open treatment. It appears to be related directly
to the extent of injury to the interosseous membrane, because it is
more common in fractures that are at the same level, in open fractures,
and after internal fixation. Early motion can significantly reduce the
incidence of this problem in internally fixed fractures.

Operative intervention for malunion is not always
indicated. As long as the hand can be used appropriately and can be
placed in the appropriate positions to perform day-to-day activities,
no additional treatment is required. This usually is in the neutral or
somewhat pronated position, allowing shoulder and elbow motion to
compensate.

The precise definition of what constitutes a malunion in
the forearm has been elusive, but recent work provides reasonably good
guidelines (54,90,96).
This is particularly an issue when one considers the need for open
reduction and internal fixation in adolescents, in whom the amount of
remolding that is possible following healing in a nonanatomic position
can be somewhat unpredictable. Matthews et al. (54)
showed that with 10° of angulation in the radius, there was minimal
functional loss in pronation and supination, whereas over 20° of
angulation functional loss occurred. Tarr et al. (96)
provided more specific information, in that they demonstrated in a
cadaver study that greater than 10° of angulation in both bones located
in the distal third of the forearm resulted in an average loss of range
of motion of 12.5% ±pm 4.5%. If this same angulation was present in the
middle third of the forearm, this loss increased to 16% ±pm 5.7%;
therefore, angulation in the middle third of the forearm is tolerated
less well than in the distal third. They found that the loss in
supination and pronation secondary to rotational malposition was
directly proportional to the degree of malrotation. Schemitsch and
Richards (90), in a retrospective review of 55
patients with forearm fractures who underwent plate fixation at 6 years
of follow-up, provided a new method of assessing radial bow and
relating this to loss of motion. Although angulation over 10° in both
bones has adverse functional effects, it appears that preservation of
the normal bow of the radius is the more critical factor. In their
patients, they compared the radial bow on comparison x-ray studies to
the normal side and measured this according to the maximum distance
between the radius and the ulna at the interosseous membrane. Their
overall results in this group of patients were excellent, in that 54 or
55 fractures in the radius and ulna healed and 84% of the patients had
satisfactory functional results. They demonstrated that restoration of
the radial bow was directly correlated with the functional outcome and
that completely normal motion

required
restoration of the radial bow to normal. In spite of the efforts made
in their series to achieve anatomic reduction of both bones, their
results show that this is difficult; the mean outcomes in their series
were 64° in pronation and 74° in supination. The normal maximum radial
bow, as measured at the interosseous membrane, in their series was 15
mm. To get 80% of normal range of motion, this had to be within 1.5 mm
of normal. They found the same direct relationship to grip strength.
Stated another way, if the maximum radial bow was within 4% to 5% of
normal, then 80% of forearm range of motion and grip strength could be
expected. As emphasized in the study conducted by Tarr et al. (96),
both the location and the amount of the loss of radial bow were
important. The overall results in their series were somewhat less good
than previously reported; the unsatisfactory functional outcomes in
their study were 16%, as compared to 15% for Anderson et al (3) and 9% for Chapman et al (14).
They attributed this to the fact that the severity of injury was
greater in their series in that all of their patients had fractures of
both bones and greater numbers of fractures were open.

There is little in the literature on the use of osteotomy for correction of forearm malunion. Trousdale and Linscheid (99)
reported on 27 osteotomies for malunion of the forearm, including 20 in
the radius, two in the ulna, and five in both. Their indications were
loss of motion in 20 (average loss 74°, range 20° to 120°), a painful
distal radioulnar joint in six, and poor cosmesis in one. One of the
most important findings in their study was that time had a significant
effect on the improvement in range of motion. Patients operated on
sooner than 12 months after the original injury gained an average of
29° of supination and pronation (range 20° to 160°, and in those
operated on more than 12 months after injury the gains were less than
half, averaging 30° (range -25° to 95°). Of the six patients operated
on for distal radioulnar joint pain, three experienced marked
improvement of their pain and achieved a stable joint, but the average
loss of range of motion in the six patients was 7° (range -25° to 25°).
The patient operated on for cosmetic problems was pleased with the
appearance of the forearm but lost 10° of rotation. Their outcomes
point out that it is possible to achieve significant improvement in
patients with forearm malunions, but the surgery is better done earlier
than later and does not have consistent results, and the fact that
Trousdale and Linscheid had complications in 11 of their 27 patients
demonstrates that the surgery is challenging.

The complications of treating malunions and nonunions of
the upper extremity are similar to those of all major surgery in the
upper extremity, including infection, neurovascular injury, failure of
the fixation, loss of joint motion, and others. The risk of these
problems can be minimized by careful attention to patient selection and
details of the surgery. The outcome depends strongly on a fully
cooperative patient who is capable of performing exercises in the face
of discomfort and who is completely compliant with postoperative
instructions.

It is somewhat hazardous to generalize about the
treatment of nonunions and malunions in the upper extremity, because
these are uncommon problems that may appear only one or two times in
the lifetime of an average surgeon. Large series are rare even in the
hands of surgeons working in major referral centers. In addition, each
patient’s problem is unique and requires an individualized approach.
Recognizing these limitations, my recommendations for the treatment of
nonunions and malunions in the upper extremity are as follows: