Background: There is a normal transition from the kyphotic alignment that is present in the spine of the newborn to the normal sagittal contours that are present in the adult spine. Although abnormal kyphosis at the thoracolumbar junction in infants is rare, it can result from congenital anomalies and bone dysplasias. We report the cases of seven otherwise normal infants who had thoracolumbar kyphosis due to lumbar hypoplasia, with total spontaneous resolution over time.

Methods: The medical records of seven patients who met the inclusion criteria were reviewed. Clinical data and radiographs were analyzed to rule out the presence of congenital anomalies or bone dysplasias. Progression of kyphosis was measured on serial radiographs made with the patient sitting and standing.

Results: All patients were managed conservatively with observation alone. No patient had a neurologic deficit. The average age at the time of the initial diagnosis was 5.3 months, and the average duration of follow-up was 5.7 years. Three cases of kyphosis were secondary to L1 hypoplasia, and four were secondary to L2 hypoplasia. The average initial kyphosis was 34.2°, which progressed to 0.4° of lordosis at the time of the latest follow-up.

Conclusions: Thoracolumbar kyphosis in normal infants secondary to lumbar hypoplasia may resolve spontaneously. After congenital anomalies and bone dysplasias are ruled out, a period of observation is advised.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.