Decompressive L5 Transverse Processectomy for Bertolotti's Syndrome: A Preliminary Study

Bertolotti's syndrome is a spinal disorder characterized by abnormal enlargement of the transverse process of the most caudal lumbar vertebra. The L5 transverse process may be enlarged either unilaterally or bilaterally and may articulate or fuse with the sacrum or ilium. Pseudoarticulation between the transverse process of the L5 and the alar of the sacrum can cause buttock pain and leg pain. In addition, the L4 exiting nerve root could be compressed by an enlarged L5 transverse process. The authors could have obtained satisfactory results from the selected cases of Bertolotti's syndrome by applying a selective transverse processectomy of the L5.

The objective of this study is to determine the effectiveness of L5 transverse processectomy for symptomatic Bertolotti's syndrome.

A retrospective study.

A total of 256 patients with Bertolotti's syndrome who had severe buttock pain and unilateral or bilateral radiating leg pain were selected. The correct diagnosis was made based on imaging studies which included computed tomography (CT), plain x-rays, and magnetic resonance imaging (MRI). The final diagnosis was made by confirming pain relief from anesthetic block. A total of 87 patients were classified into 2 groups: group A included 50 patients whose pain was relieved by block into the pseudoarticulation and group B included 37 patients whose pain was relieved by block into the L4 exiting nerve root. A total of 61 cases (group A: 39 cases, group B: 22 cases) were selected as pure L5 transverse processectomy.

The primary outcome measures were reduction in pain scores and improvement in quality of life.

Among 61 patients, there were 19 men and 42 women. The mean age of the patients was 53.2 ± 12 years (group A: 57.8 ± 14 years [16 - 86 years], group B: 53.4 ± 14 years [27 - 77 years]). The mean follow-up period was 6.5 months. The patients' mean visual analog scale (VAS) prior to surgery was 7.54 ± 0.81 (group A: 7.59 ± 0.93, group B: 7.50 ± 0.86), and the mean postoperative VAS was 2.86 ± 1.67 (group A: 3.82 ± 1.59, group B: 2.05 ± 1.00). According to Macnab's criteria, 12 patients showed excellent results (group A: 3, group B: 9), 41 patients showed good results (group A: 11, group B: 30), 6 patients showed fair results (group A: 5, group B: 1), and 2 patients showed poor results (group A: 2, group B: 0). Thus, satisfactory results were achieved in 86.89% of the cases.

In patients with Bertolotti's syndrome, pseudoarticulation as well as L4 nerve root compression can be the source of buttock pain and lower extremity pain. Bisectional cutting of the L5 transverse process and decompression of the L4 nerve root could be an optimal treatment for Bertolotti's syndrome, and it may be easily approached by the paraspinal approach.

This is a retrospective study and only offers one-year follow-up data for patients with Bertolotti's syndrome who have undergone L5 transverse process resection.Key words: Bertolotti's syndrome, pseudoarticulation, L5 transverse processectomy, paraspinal approach.