A Comparative Evaluation of Surgical Techniques Applied in Lumbar Synovial Cysts in Accordance with the Literature

<b>Background/Objectives:</b> The aim of this study was to compare the clinical outcomes of cyst excision alone and the combination of excision and unilateral dynamic instrumentation in the surgical treatment of lumbar synovial cysts at the L4-L5 level and to determine which surgical approach is more effective. <b>Methods:</b> Thirty-three patients who underwent operations on the L4-L5-level synovial cyst in a single center between January 2015 and January 2021 were included in this retrospective study. Patients were divided into two groups: cyst excision only (<i>n</i> = 18) and excision with unilateral dynamic instrumentation (<i>n</i> = 15). The pain levels of the patients were assessed by VAS score, and their functional status was assessed by the Oswestry Disability Index. The mean follow-up period was 28.2 ± 4.0 months in the excision group and 27.6 ± 4.4 months in the instrumentation group. <b>Results:</b> VAS and ODI scores improved significantly in both groups (<i>p</i> < 0.001). The improvement in low back pain VAS scores was more significant in the instrumentation group (delta VAS: -5.8 ± 1.3 vs. -5.0 ± 1.2, <i>p</i> = 0.042). The complication rate was 27.8% in the excision group and 13.3% in the instrumentation group. The development of listhesis was significantly more frequent in the excision group (16.7% vs. 0%, <i>p</i> = 0.028). Reoperation rates were 16.7% in the excision group and 6.7% in the instrumentation group. <b>Conclusion:</b> Although both surgical approaches are effective in the treatment of synovial cysts at the L4-L5 level, the addition of dynamic instrumentation unilaterally seems to be more advantageous, especially in the control of low back pain and prevention of listhesis risk. The choice of surgical technique should be individualized by considering patient-specific factors.