Synovial facet joint cysts of the spine have been documented in several investigations as a primary lesion. Although the specific pathophysiology of those cysts is unknown, degeneration and instability appear to be underlying causes. However, just a few studies have looked into spinal synovial cysts as a postoperative consequence of decompression surgery. The authors focused on synovial cysts of the lumbar facet joints as consequences after lumbar decompression surgery in this retrospective clinical investigation to clarify their etiology.

The study included 326 individuals with 384 segments who had posterior decompression surgery without fusion. About 107 pieces were surgically decompressed unilaterally, while 277 were surgically decompressed bilaterally. After surgery, 18 of the 384 segments developed asymptomatic facet synovial cyst as a side effect. They used plain radiographs, CT scans, and MR images to assess these segments’ anatomical and morphological characteristics.

Bilateral lumbar posterior decompression treated all 18 segments with a postoperative lumbar facet synovial cyst. Although 17 of the 18 segments showed facet articular spondylotic alterations, there was no significant radiological lumbar spinal instability in any of them. Furthermore, in the neutral posture, 12 of the 18 individuals had lumbar retrolisthesis.

According to the findings, patients with the lumbar degenerative disease who have a potential biomechanical lumbar instability such as disruption of the facet articular surface, hydrarthrosis, or lumbar facet tropism may have a high risk of lumbar facet synovial cyst formation following bilateral posterior decompression surgery.