Background:

Controversy remains about the choice of reduction or arthrodesis in situ for surgical management of adolescent spondylolisthesis, while no systematic review and meta-analysis were performed to determine which one is the optimal surgical choice. The study aims to compare outcomes of the two surgical strategies for adolescent spondylolisthesis.

Methods:

A comprehensive search was performed through PubMed, Web of Science, Cochrane Library, Embase, OVID/MEDLINE, CBM, CNKI, and Wanfang with a cutoff date of May 21st, 2021. Search terms included “spondylolisthesis”, “in situ” and “reduction”. Included studies had following characteristics: (I) participants: adolescents with spondylolisthesis. (II) Intervention: reduction following arthrodesis. (III) Control: arthrodesis in situ. (IV) Outcomes: postoperative clinical and/or radiographic results. (V) Study design: randomized controlled trial (RCT), cohort or case-control study. Data were analyzed with Review Manager 5.4, and risk of bias assessment of studies was assessed via Newcastle-Ottawa quality assessment scale (NOS).

Results:

Six cohort studies were included, with NOS scores of all ≥6. There were no significant differences regarding operative time [mean difference (MD) =152.62; 95% [confidence interval (CI)]: -54.02 to 359.26; I 2 =96%; P=0.15], blood loss (MD =786.61; 95% CI: -646.82 to 2,220.04; I2 =90%; P=0.28), patient satisfaction (MD =1.98; 95% CI: 0.72 to 5.43; I2 =0%; P=0.18), neurological complications (MD =1.02; 95% CI: 0.25 to 4.18; I2 =0%; P=0.98), or total complications (MD =0.59; 95% CI: 0.29 to 1.19; I2 =0%; P=0.14). However, patients undergoing reduction achieved better radiographic results: fusion rate (MD =3.09; 95% CI: 1.22 to 7.84; I 2 =40%; P=0.02), postoperative pseudarthrosis (MD =0.35; 95% CI: 0.15 to 0.79; I2 =24%; P=0.01), percentage of slippage (MD =-20.58; 95% CI: -26.32 to -14.84; I2 =0%; P<0.00001), and slipping angle (MD =-10.05; 95% CI: -14.55 to -5.54; I2 =0%; P<0.0001). And no overt publication bias was found in the studies.

Conclusions:

Both reduction and arthrodesis in situ in adolescent spondylolisthesis are safe and demonstrate good clinical outcomes. However, reduction showed better radiographic results and was associated with less pseudarthrosis, better relief of disability, and improvements in self-image. In conclusion, reduction may be the optimal choice compared with arthrodesis in situ, but further verification of these findings is recommended using RCTs.