Copyright © 2009 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Jeffrey A. Rihn, MD, and Alexander R. Vaccaro, MD, PhD*,
Rothman Institute, Philadelphia, Pennsylvania
Posted January 2009
The optimal treatment of thoracolumbar burst fractures remains
a controversial topic. It is unclear from the current literature which fractures
require surgical treatment and, if surgery is necessary, which surgical
approach provides the best outcome. This study evaluates the surgical treatment
of unstable thoracolumbar burst fractures and proposes a technique that can
reliably restore anterior and posterior spinal column stability, prevent the recurrence
of deformity and failure of instrumentation in the postoperative period, allow
for neurological recovery, and preserve motion segments. Traditional teaching
suggests that unstable burst fractures with neurological compromise and substantial
anterior thecal sac compression should be treated with an anterior
decompression and stabilization with or without posterior stabilization. More
recent techniques, however, are an attempt to achieve the same goals while
avoiding the morbidity that is associated with an anterior approach. Furthermore,
these techniques focus on the use of short-segment posterior instrumentation to
spare motion segments and the use of cement support to avoid the dilemma of
anterior column insufficiency.
Short-segment reduction and fixation of unstable burst
fractures alone has resulted in an unacceptably high rate of instrumentation
failure and correction loss1. In 2001, Alanay et al.2 performed a prospective randomized study in which they compared short-segment
instrumentation alone to short-segment instrumentation combined with
transpedicular intracorporeal bone-grafting without objective end-plate
restoration. These authors found that short-segment instrumentation with or
without transpedicular grafting was associated with a failure rate of up to
50%. This study did not include patients with neurological injury2.
The current study evaluated the treatment of unstable burst
fractures, many of which had associated neurological deficit. In addition to
the traditional method of indirect fracture reduction with use of patient
positioning and posterior instrumentation, the technique described in this
study also involved transpedicular, balloon-assisted reduction and anterior
stabilization through injection of calcium phosphate cement. A posterior
decompression was also performed in patients who had neurological deficit or a canal
compromise of >50%. The authors found that this technique provided adequate
anterior and posterior stabilization, with little loss of correction and a low
rate of instrumentation failure (i.e., 7%) postoperatively. Furthermore, all
patients had maintenance or improvement of neurological function. Clinically
significant posterior cement extrusion does not seem to be an issue if careful
technique is followed.
Short-segment instrumentation combined with anterior
stabilization with polymethylmethacrylate has been shown to produce similar
results, with maintenance of correction and a zero rate of instrumentation
failure3. Unlike polymethylmethacrylate, however, calcium phosphate
cement can theoretically facilitate rather than impede fracture-healing.
This study is limited in that it is an observational in
nature; it offers no comparison to nonoperative treatment, short-segment
posterior fixation alone, anterior decompression and stabilization, or combined
anterior and posterior decompression and stabilization. Nonetheless, this study
does suggest that the proposed technique is effective in providing lasting
correction of the kyphosis, in stabilizing the fracture, and in facilitating
neurological recovery. This effectiveness, we would conjecture, is the result
of end-plate elevation and conferred stability at the juncture between the disc
and the end plate. The technique of balloon-assisted fracture reduction of the
superior end plate and anterior column reconstruction with use of calcium
phosphate bone cement appears, from the results reported in this article, to provide
adequate vertebral height restoration and anterior column support. The obvious
concern, particularly when using cement in a patient with disruption of the
posterior vertebral wall, is posterior cement extrusion and spinal cord
compression. This, however, has not been shown to be an issue in this and other
series4,5. Nevertheless, continued skepticism is necessary on this
issue until more predictable methods of preventing this catastrophic
complication are developed. In our view, there is certainly a learning curve
when performing this technique, and it is likely that operative experience is
paramount to obtaining a good result and avoiding cement-related complications.
Further studies are needed to adequately study this
technique with use of appropriate comparison groups. In the meantime, this
study provides some evidence that supports the use of this technique in the
setting of unstable burst fractures.
*The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
References
1. McLain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. A preliminary report. J Bone Joint Surg Am. 1993;75:162-7.
2. Alanay A, Acaroglu E, Yazici M, Oznur A, Surat A. Short-segment pedicle instrumentation of thoracolumbar burst fractures: Does transpedicular intracorporeal grafting prevent early failure? Spine. 2001;26(2):213-7.
3. Cho DY, Lee WY, Sheu PC. Treatment of thoracolumbar burst fractures with polymethyl methacrylate vertebroplasty and short-segment pedicle screw fixation. Neurosurgery. 2003;53:1354-61.
4. Verlaan JJ, Dhert WJ, Verbout AJ, Oner FC. Balloon vertebroplasty in combination with pedicle screw instrumentation: a novel technique to treat thoracic and lumbar burst fractures. Spine. 2005;30:E73-9.
5. Korovessis P, Repantis T, Petsinis G, Iliopoulos P, Hadjipavlou A. Direct reduction of thoracolumbar burst fractures by means of balloon kyphoplasty with calcium phosphate and stabilization with pedicle-screw instrumentation and fusion. Spine. 2008;33:E100-8.
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