Lg. Lenke et al., RECOGNITION AND TREATMENT OF THE PROXIMAL THORACIC CURVE IN ADOLESCENT IDIOPATHIC SCOLIOSIS TREATED WITH COTREL-DUBOUSSET INSTRUMENTATION, Spine (Philadelphia, Pa. 1976), 19(14), 1994, pp. 1589-1597
Study Design. A retrospective radiographic and clinical review of a co
nsecutive series of patients with adolescent idiopathic scoliosis (AIS
) instrumented/fused with Cotrel-Dubousset instrumentation (CDI) was u
ndertaken. Objective. The authors determined criteria when the upper t
horacic curve should be instrumented/fused in AIS treated with CDI and
assessed the results of surgical treatment. Summary of Background Dat
a. Failure to recognize and include the upper left thoracic curve in t
he instrumentation/fusion of a lower right thoracic idiopathic scolios
is may produce shoulder imbalance and coronal decompensation. Patients
with an elevated left shoulder clinically or a positive T1 tilt radio
graphically usually require instrumentation/fusion of the proximal tho
racic curve. However, the upper left thoracic curve may be structural
and require inclusion in the instrumentation/fusion when the shoulders
clinically are level or even if the right shoulder is elevated preope
ratively when using CDI. Methods. The authors compared 27 patients wit
h AIS with structural upper thoracic curves that were instrumented wit
h CDI to T2 (Group I) to 27 patients with King Type III curves treated
with CDI that did not have the upper thoracic curve instrumented/fuse
d (Group II). Results. The distinguishing Group I preoperative criteri
a indicating a structural upper thoracic curve included a proximal tho
racic curve greater than 30-degrees that corrected to no better than 2
0-degrees on sidebending; greater-than-or-equal-to Grade I rotation or
greater-than-or-equal-to 1 cm translation present at the apex of this
curve; any elevation of the left shoulder or tilt of T1 into the conc
avity of the upper thoracic curve; or when the transitional vertebra b
etween the two curves is at T6 or below. Conclusions. When these afore
mentioned criteria are present and surgical correction with CDI is pla
nned, we recommend extending the instrumentation up to T2 to produce l
evel shoulders and maintain coronal balance.