Synovial Cyst of Thoracic Spine: A Systematic Literature Review and Meta-Analysis.

Objective: Thoracic spine synovial cysts (TSSC) are rare. Only case reports and a few small series, but no systematic review, have been published so far. This article aimed to update all the TSSC cases and analyze data in addition to reporting three cases.

Methods: This is a retrospective systematic review and metanalysis of reported cases of TSSC, located between T1-2 and T12-L1, until 2024. Data extraction and collection were done by multiple reviewers, and statistical analysis was performed.

Results: A total of 39 reports were identified and 62 cases of TSSC were analyzed, the mean age being 64.05+/-18.14 years. Males were more numerous (61.66%) and were significantly older than females (P = 0.035). Myelopathy with gait difficulty was the most common presenting symptom (56.5%). Motor weakness was significantly associated with older age (P = 0.034) and back pain with females (P = 0.020). Resection of cysts without fusion was performed in 90% of cases. Surgical outcome did not vary with or without fusion. The three reported cases in this study are two males and one female. Two were at T11-12 and one at T1-2, underwent surgical resection of the cyst without fusion and had a satisfactory outcome.

Conclusions: TSSC are more common in elderly males, mostly occur in the lower thoracic spine, below T7. Most of them present with myelopathy and motor weakness and are cured with resection of the cyst without the need for spinal fusion. There was no report of recurrence or revision surgery.