Question: In patients with burst fractures of the second, third, and
fourth lumbar vertebrae, what is the effectiveness of combined anterior and
posterior short-segment transpedicular fixation (SSTF) compared with posterior
SSTF alone?
Design: Randomized (allocation
concealed)*, blinded (manuscript
writers)*, controlled trial with
a mean 46 to 48-month follow-up.
Information provided by author.
Setting: A hospital in Greece.
Patients: 40 patients (78% men) with L2 to L4 lumbar Type-A3 burst
fractures caused by a fall from a height or a traffic accident. Inclusion
criteria were a Magerl classification of A3 with a combined load-sharing score
of =6, a single-level injury, and a fracture that had occurred within the
previous week. Exclusion criteria were multiple trauma, severe osteoporosis,
spinal deformity, degenerative or other spinal stenosis, or previous spinal or
abdominal surgery. Follow-up was 100%.
Intervention: Patients were allocated to combined anterior
(including partial corpectomy) and posterior stabilization with use of a mesh
cage filled with autologous iliac bone graft and SSTF, including 1 vertebra
above and below the fractured vertebra (n = 20), or to posterior SSTF alone (n
= 20).
Main outcome measures: Operative outcomes (time, blood loss, and
hospital stay), loss of correction (Gardner angle), neurologic deterioration
(Frankel grade), pain (visual analogue scale [VAS]), and functional outcome
(Short Form-36 [SF-36]).
Main results: Patients who received combined surgery had a longer
operative time, more blood loss, and a longer hospital stay than patients who
received posterior SSTF alone
(Table). The Gardner angle loss
of correction was 2° in the combined surgery group and 5° in the group
that had posterior SSTF alone. The Gardner angle was significantly correlated
with spinal canal encroachment in the posterior SSTF alone group before
surgery (p < 0.01), after surgery (p < 0.01), and at the time of final
follow-up (p < 0.001), while the correlation was only significant with the
combined surgery group at the time of final follow-up (p < 0.001). No
neurologic deterioration occurred after surgery in either group. At the time
of follow-up, the Frankel grade was correlated with spinal canal clearance in
patients who received posterior SSTF alone (p < 0.02). VAS scores did not
differ between groups; SF-36 scores in the domains of bodily pain and physical
function improved in the posterior SSTF alone group. VAS and SF-36 scores were
not correlated with loss of kyphotic angle correction or anterior or posterior
vertebral body height ratio in either group.
Conclusions: In patients with burst fractures of the second, third,
and fourth lumbar vertebrae, combined anterior and posterior short-segment
transpedicular fixation (SSTF) was associated with longer operative times,
more blood loss, and a longer hospital stay than posterior SSTF alone.
Although some increased loss of correction occurred in the group that had
posterior SSTF alone, the SF-36 scores were better.
Whether mid-lumbar burst fractures are best treated by combined anterior
and posterior SSTF, posterior SSTF alone, or anterior SSTF alone is
controversial. The study by Korovessis and colleagues attempts to address part
of the question by using a randomized trial design comparing combined anterior
and posterior surgery with posterior SSTF alone.
The conclusions depend almost entirely on what variables are deemed to be
important in patient care. Korovessis and colleagues conclude that posterior
SSTF alone "seems not to be an option for A3 fractures in mid-lumbar
spine" on the basis of a 3° difference in kyphosis on final
evaluation. I would draw entirely different conclusions. Although, at the time
of final follow-up, the combined anterior and posterior SSTF group had a
2° loss of correction in the Gardner angle whereas the posterior SSTF
alone group had a 5° loss, was this difference of any clinical importance?
It was certainly not, according to the data presented. The SF-36 scores for
physical and bodily pain were better in the group that had posterior SSTF
alone. I would also stress that the group that had posterior SSTF alone had
shorter operative times, less blood loss, and a shorter hospital stay than the
combined anterior and posterior group. We treat patients, not radiographs.
This study is very well done and, in my mind, confirms the usefulness of an
SSTF through a posterior approach alone for mid-lumbar burst fractures.