F. Fahim, F. Mohammad Moradi, A. Mojtahedzadeh, A. Shahinzadeh, A. Khorram, P. Amini, D. Farhadian, P. Sangtarashha, M. Faramin Lashkarian, F. Khazaei, A. Zali
Background: Pain relief is the principal patient-centered goal of surgery for symptomatic lumbar synovial facet cysts, yet comparative reviews have often emphasized cyst recurrence. Whether adding fusion improves postoperative pain or reduces later surgery remains uncertain. Objective: To compare decompression alone with decompression plus fusion, with postoperative back- and leg-pain outcomes as the primary domain. Methods: PubMed, Embase, Scopus, Web of Science, and the Cochrane Library were searched from inception to 2 June 2026. Comparative cohorts and case series with at least five patients were eligible. Twenty-two studies were re-extracted for VAS/NRS scores, change scores, and persistent or recurrent pain. Random-effects restricted maximum likelihood models with Hartung-Knapp inference were used; clinically distinct pain outcomes were analyzed separately. Results: Twenty-two studies (16 cohorts, 6 case series; 51,899 participants) were included. Two studies provided compatible final VAS data. Fusion did not improve postoperative back pain (MD -0.04, 95% CI -0.17 to 0.10; I2=0%) or leg pain (MD -0.03, 95% CI -0.28 to 0.21; I2=0%). Postoperative back pain (RR 0.58, 95% CI 0.14-2.30) and leg/radicular symptoms (RR 0.75, 95% CI 0.42-1.32) were also not significantly reduced. Fusion decreased confirmed cyst recurrence (RR 0.29, 95% CI 0.15-0.57) but not reoperation or subsequent lumbar surgery (RR 0.80, 95% CI 0.42-1.50). Conclusion: Current comparative evidence does not demonstrate superior postoperative pain control with routine fusion. Fusion reduces cyst recurrence without clearly reducing reoperation, supporting selective use when instability is present or anticipated.