To investigate the time course of signal changes in the adjacent pedicle in fresh pediatric lumbar spondylolysis.
A recent study reported that high signal change (HSC) on T2-magnetic resonance image (MRI) in the pedicle adjacent to the pars interarticularis could be an indicator of early spondylolysis. In addition, the HSC-positive pars defects showed significant better bony healing than the HSC-negative pars defects. However, there has been no report on the time course and the duration of HSC.
We prospectively investigated 10 boys and 5 girls with fresh lumbar spondylolysis showing HSC in the adjacent pedicle. Their mean age was 15.1 years, ranging from 10 to 17 years. Two patients had multilevel unilateral spondylolysis. Among 15 patients, HSC was found in 22 (12 unilateral and 5 bilateral) pedicles. At the first presentation, the diagnosis of spondylolysis was made based on the plain radiograph findings, multidetector computed tomograms (CTs), and MRI. Every month from the first presentation, follow-up MRIs were taken. When HSC disappeared, multidetector CT was taken to confirm bony healing of the pars defect.
Bony healing of the pars was obtained in 21 out of 22 defects. The bony healing rate was 95.6%. In 19 pedicles of 12 patients, HSC gradually diminished by every month until it disappeared 3 months later, and radiologic osseous healing was confirmed by CT in all but 1 patient. In the 3 remaining pedicles of 3 patients, HSC took more than 4 months to disappear.
In this study, HSC disappeared in most pedicles on the 3-month follow-up MRI. In patients who did not comply with treatment, HSC tended to last longer. These results led us to hypothesize that MRI at the third month during follow-up can indicate whether the conservative treatment is being successful or not.
High signal change disappeared in most of the pedicles within 3 months of conservative treatment. These results led us to hypothesize that magnetic resonance image at the third month during follow-up can indicate whether the conservative treatment is being successful or not.
From the *Department of Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima; and †Department of Orthopedics, Suihou Daiichi Hospital, Hyogo, Japan.
Acknowledgment date: August 3, 2009. Revision date: October 12, 2009. Acceptance date: November 3, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Address correspondence and reprint requests to T. Sakai, MD, Department of Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan; E-mail: firstname.lastname@example.org