A nine-year-old left-hand-dominant child sustained an injury
to the left upper extremity while competing in an equestrian event.
The child was riding a horse at a speed estimated at 10 mph as she approached
a jump. She came too close to the side post that provides support
for the jump, and, as the horse jumped, the girl’s left
forearm struck the post. At the time of impact the shoulder was
fully extended and slightly externally rotated, and the elbow was
flexed to 90°. She remained in the saddle, and her forward motion
continued, resulting in severe deformity of the left upper extremity.
She remained conscious throughout, and she was transported to an
outside institution for evaluation and treatment.
In the emergency room she was found to have a closed fracture
of the humeral shaft with a palpable left radial pulse and normal
motor and sensory function in the left hand. The emergency-room
physician noted an abnormal skinfold anteriorly over the humerus.
Radiographs demonstrated minimal apparent deformity, and the arm
was placed in a coaptation splint. Repeat anteroposterior and lateral radiographs
of the arm in the splint demonstrated acceptable fracture alignment.
The emergency-room physician expressed concern regarding the abnormal
anterior skinfold, and a magnetic resonance imaging scan of the
arm was obtained. However, no rotational abnormality of the humerus
was appreciated, and the position of immobilization was not changed.
The arm remained in the coaptation splint for a total of seven weeks.
When the splint was removed, she was noted to have an elbow flexion
contracture as well as an absence of external rotation of the shoulder,
which did not improve despite three weeks of occupational therapy.
The patient initially presented to our institution at ten weeks
after the injury with a cosmetically unacceptable skinfold over
the anterior aspect of the arm and severely limited elbow extension.
The left upper extremity was well perfused with a palpable radial
pulse, and the results of neurological examination of the hand and
arm were entirely normal. On clinical inspection she had an abnormal
spiral skinfold over the anterior aspect of the left humerus that
started proximally and medially and extended distally and laterally
(Fig. 1).
There was no deformity in the coronal or sagittal plane. The passive
range of motion of the left shoulder was 160° of abduction, 160°
of forward flexion, 220° of internal rotation, and 0° of external rotation
compared with 180° of abduction, 180° of forward flexion, 100° of
internal rotation, and 90° of external rotation on the uninvolved,
right side. Rotation was measured from a neutral position with the
forearm pointing straight ahead. The fracture site was nontender,
and there was no motion at the fracture site. Evaluation of the
passive range of motion demonstrated a 45° flexion contracture with further
flexion possible to 125°.
Radiographs demonstrated a healing fracture of the midpart of
the humeral shaft with 17° of valgus angulation (Figs. 2-A and 2-B). A scanogram revealed
7 mm of shortening at the fracture site. At the time of our initial
clinical examination, the diagnosis of rotational malunion of the
humerus with approximately 270° of external rotation of the distal
fragment was postulated. A repeat high-resolution magnetic resonance
imaging scan of the arm was made in order to ascertain the course
of the neurovascular structures, especially the radial
nerve. The scan confirmed the diagnosis of severe rotational malunion
of the humerus (Figs. 3-A and 3-B) and the position of the radial
nerve passing anteriorly over the midpart of the humeral shaft.
Four months after the initial injury, the patient underwent derotation
osteotomy and internal fixation of the left humerus with radial
nerve exploration. A "barber pole" spiral skin
incision was made over the anticipated course of the radial nerve.
The incision was located anteriorly over the midpart of the humeral
shaft, starting proximally and medially and extending in a distal
and lateral direction along the line of the abnormal skinfold.
The radial nerve was first identified distally on the lateral
side of the humerus at its anatomic location between the brachioradialis
and the brachialis. It was dissected proximally around the anterior
aspect of the humerus in the line of the skin incision. The triceps
muscle and tendon were found lying over the anterior aspect of the
humerus at the malunion site. At the level of the midpart of the
humeral shaft, the radial nerve was followed to its normal location
in the interval between the medial and lateral heads of the triceps
muscle. With the nerve directly visualized and protected, subperiosteal
dissection was performed for approximately 4 cm on either side of
the malunion site. An osteotomy was performed carefully with use
of an oscillating saw, and the entire distal humerus was internally
rotated 270° while the radial nerve was under direct visualization.
The osteotomy was then fixed with use of a seven-hole 3.5-mm dynamic
compression plate. The initial "barber pole" spiral
incision became a straight lateral incision at the completion
of the derotation maneuver, and the abnormal skinfold disappeared
completely. Immediately after derotation, the hand remained well
perfused, and the patient regained full extension at the elbow.
One year postoperatively the limb remained completely intact
neurovascularly. The patient had regained a full range of motion
of the shoulder with 180° of abduction, 180° of forward flexion,
100° of internal rotation, and 90° of external rotation. She also
had a full range of motion of the elbow, with 150° of flexion and
0° of extension. The skin incision had healed uneventfully, and
radiographs demonstrated union at the osteotomy site.
A review of the literature supports the idea that closed humeral
shaft fractures are, in general, forgiving fractures that are best
treated nonoperatively3,4,6-8. There are wide ranges of parameters
for acceptable reduction of closed fractures of the midpart of the
humeral shaft in children9. Between
1 and 2 cm of shortening is acceptable and, indeed, may be desirable
as overgrowth of approximately 1 cm may occur6,10,11. Rotational malunion with internal
rotation up to 15° is common and very well tolerated3,4. Up to 30° of varus and 20° of
anterior bowing may be present before becoming clinically apparent8. Several cases of humeral shaft fracture
caused by an external rotation force in arm wrestlers have been
reported, but none of them required operative intervention12. A single case of extreme (360°)
external rotation deformity secondary to a closed humeral fracture
in a child was described in the literature5.
The clinical appearance of the arm of this eleven-year-old girl
was identical to that of our patient, with "spiral skin
creases extending from just beneath the axilla to two transverse
finger breadths above the elbow."5 The
rotation deformity was not diagnosed on initial evaluation in the
emergency room in that case either, but the child was immediately
referred for further evaluation secondary to a radial nerve neurapraxia.
The rotation deformity was then diagnosed, and a closed reduction
was successfully performed under general anesthesia. The fracture healed
uneventfully, and the radial nerve neurapraxia resolved completely
by three months after the injury.
The indications for operative intervention in our patient were
the extreme loss of motion of the shoulder and elbow as well as
the cosmetically unacceptable skinfold over the anterior aspect
of the humerus. This patient could not externally rotate the shoulder
because of the 270° external rotation malunion. The 45° elbow flexion
contracture was secondary to functional shortening of the biceps
muscle as it spiraled around the humerus. Although this patient
had acceptable alignment radiographically, the decreased range of
motion and the clinical appearance suggested the possibility of a
persistent postinjury rotation malalignment of the humerus. The
repeat high-resolution magnetic resonance imaging scan confirmed
this diagnosis and provided details of the neurovascular and muscular anatomy
that helped with the planning and performance of the operation.
Despite 270° of external rotation at the site of the fracture,
this patient did not have neurological or vascular compromise. The
prevalence of radial nerve palsy with closed fractures of the midpart
of the humeral shaft in adults is as high as 17%13. In our patient external rotation
of the distal fragment and shortening at the fracture site may have decreased
the tension on the radial nerve. External rotation of the distal
fragment may have "unwound" the radial nerve so
that excessive stretch was avoided despite the substantial rotation deformity.
This case illustrates the importance of careful clinical examination
of the adjacent joints and overlying soft tissues in the setting
of skeletal trauma despite normal neurovascular status and grossly
normal radiographs. We believe that surgical intervention could
have been avoided in this unusual case if the rotation deformity
had been recognized promptly.