Afifty-five-year-old man who performed manual labor working as a machine
operator presented to an orthopaedic surgeon with a chief symptom of
difficulty using his upper and lower limbs. He reported the insidious onset of
increasing neck pain at the base of the skull over the preceding several
years, which had been associated with progressively worsening bilateral upper
and lower-extremity weakness for the previous three months. The patient had
been unable to work or participate in his normal activities of daily living
for approximately two months because of the arm weakness. The musculoskeletal
history revealed that he had sustained a cervical spine fracture at the age of
sixteen years while playing football, which was treated with a neck brace for
approximately three months.
On physical examination, the patient appeared to be a well-developed,
well-nourished man with a range of motion of the neck of 45° of rotation
bilaterally as well as the ability to perform chin-to-chest flexion and
vertical extension to neutral. Marked weakness was identified in the upper and
lower extremities bilaterally, with 3+ to 4- (of 5) global strength of the
upper extremities and 4+ to 5- global strength of the lower extremities. The
reflexes were symmetrical in the upper and lower extremities, and the patient
had continuous clonus in the right ankle with three beats in the left ankle.
He had decreased light-touch sensation in the ulnar distribution of the left
upper extremity. The results of Babinski testing were equivocal bilaterally.
Proprioception was within normal limits in the fingers and toes bilaterally,
and the gait was normal. The Hoffmann sign was negative, and he had no
evidence of difficulty performing rapid alternating movements.
Anteroposterior, lateral, and flexion-extension radiographs of the cervical
spine demonstrated a chronic Anderson and
D'Alonzo3 type-II
dens fracture with marked subluxation of 2 cm
(Figs. 1-A and 1-B). Forward
flexion made the subluxation slightly worse, whereas extension reduced it by
approximately 1 cm. Magnetic resonance imaging of the cervical spine revealed
a reduced space for the spinal cord, with several views revealing a tight
constriction of the spinal canal at the C1-C2 cervical vertebral levels as
well as mild C3-C4 stenosis (Figs. 2-A,
2-B, and 2-C). The diameter of the space available for the spinal
cord measured 5 × 12 mm at the level of the most severe stenosis, and a
signal change indicative of chronic spinal cord irritation was identified at
this level.
The patient was diagnosed as having an ununited type-II dens fracture with
anterior subluxation and spinal cord impingement resulting in progressive
myelopathy. He was taken to the operating room for placement of a halo vest
and subsequent closed reduction under cervical traction while he was awake.
The halo ring was placed and, under fluoroscopic guidance, gentle traction was
added in 5-lb (2.3-kg) increments to a total of 25 lb (11.3 kg). By keeping
the neck in extension, it was possible to partially reduce the subluxation.
The partial reduction was confirmed radiographically, and the halo ring was
secured to the vest.
For definitive treatment, the patient underwent open reduction of the C2
vertebral fracture-subluxation through a posterior approach two days later. A
posterior arthrodesis of C1 and C2 was accomplished with use of autogenous
iliac crest bone graft and was secured with atlantoaxial cable wiring. Open
reduction was accomplished by posterior translation of the C1 arch by means of
the sublaminar cables, and a 4.0-diameter fully threaded transarticular screw
was placed through the right C2 vertebral pars interarticularis across the C1
and C2 vertebral facets for fixation. The patient tolerated the procedure well
and had an uneventful postoperative course. Intravenous dexamethasone was
administered in the perioperative period. As a result of the degree of force
required to reduce the fracture and the relatively poor bone density, it was
thought that the patient would benefit from the use of the halo vest for an
additional ten weeks. The upper and lower-extremity strength returned to
normal within three months postoperatively and the clonus resolved as well,
allowing him to return to work as a laborer.
Four years after the spine operation, the patient returned for follow-up
and reported new-onset left-sided neck pain. He stated that he had no weakness
or paresthesias in the upper or lower extremities. On physical examination, he
had approximately 40° of neck rotation bilaterally, was able to perform
chin-to-chest flexion, and had vertical extension of approximately 20°
past neutral. The neurologic examination revealed 5 of 5 upper and
lower-extremity strength bilaterally with a normal gait. Radiographs revealed
a solid C1-C2 fusion with no evidence of abnormal alignment or instability
(Figs. 3-A and 3-B). A cervical
magnetic resonance imaging scan made at this time revealed adequate space for
the spinal cord and cervical roots, but there was mild multilevel spondylosis
and signal change in the cervical spinal cord consistent with myelomalacia.
The patient was referred to a physical therapist, and the pain resolved
without additional intervention.