Background: Lumbosacral agenesis is a rare congenital
anomaly. There is no consensus regarding the optimal orthopaedic
management of the spinal anomaly and the concomitant lower-extremity deformities.
We propose a method to predict ambulatory potential and to identify
patients who will benefit from early operative treatment of the
lower-extremity deformities to facilitate walking.
Methods: We reviewed the records and radiographs
of eighteen patients with total or partial absence of the lumbar
spine and total absence of the sacrum. Thirteen patients (Group
I) had lumbosacral agenesis alone, and five patients (Group II)
had a concomitant myelomeningocele. Three types of spinal deformity
were identified. In Type A, there was either a slight gap between
the ilia or the ilia were fused in the midline. One or more lumbar
vertebrae were absent. The caudad aspect of the spine articulated
with the pelvis in the midline, maintaining its vertical alignment.
In Type B, the ilia were fused together, some of the lumbar vertebrae
were absent, and the most caudad lumbar vertebra articulated with
one of the ilia, with the most caudad aspect of the spine shifted
away from the midline. In Type C, there was a total agenesis of
the lumbar spine, the ilia were fused together, and there was a
visible gap between the most caudad intact thoracic vertebra and
Results: In Group I, all seven patients with Type-A
deformity were community ambulators and one patient with Type-B
was a household ambulator. No other patient in the series was able to
walk. Nine patients had cervical spine anomalies, and seven patients
had scoliosis. No patient was managed with a spinopelvic fusion.
Conclusions: We believe that all Group-I, Type-A
patients should have correction of lower-extremity deformities as
they have a very good potential to walk. The other patients should
have operations on the lower extremities only if the deformities
preclude sitting or wearing shoes or braces. The cervical spine
should be examined radiographically for atlantoaxial instability
or congenital anomalies.