Results of surgical treatment of pediatric spondylolysis and spondylolisthesis

Patients with low grade spondylolysis or spondylolisthesis rarely require surgery, as a majority respond to activity modification, NSAIDs, or physical therapy. For symptomatic patients who do not respond to conservative measures, surgical management is indicated. This may be accomplished with direct pars interarticularis repair by compression screw, wiring technique, sublaminar-hook-screw construct, or modifications thereof. Additionally, posterolateral fusion with or without instrumentation offers similar subjective, clinical, and functional long-term outcomes to direct repair with a tradeoff of longer surgical time with greater exposure needed. Overall, both procedures offer good and excellent outcomes, even with radiographic findings of pseudarthrosis. For patients with high grade slip, in situ fusion or reduction and fusion are both valid options and depend upon surgeon experience and underlying patient function and neurologic status. For patients undergoing reduction, wide decompression and instrumentation with either circumferential or interbody fusion provide stable long-term results. Interbody fusion techniques show greater long-term fusion rates, achieve greater reduction, and appear to have higher functional outcome compared to posterior-only fusion. Reduction carries increased risk of neurologic injury, but the majority of these including cauda equina resolve. Long-term follow-up comparing in situ fusion to reduction with fusion of high grade spondylolisthesis has shown improved ODI and SRS scores with fusion in situ. Grade V spondylolisthesis presents several unique challenges for surgical repair and may be fused in situ from an anterior or posterior approach, with partial reduction, or Gaines procedure. Current trends have moved towards posterior-only approach with combined posterior and interbody fusion.