Endoscopic and percutaneous minimally invasive repair of pars interarticularis defects: a systematic review of clinical outcomes

PURPOSE: Direct pars interarticularis repair preserves motion and avoids adjacent segment degeneration associated with fusion. Endoscopic and percutaneous minimally invasive techniques aim to reduce tissue disruption and accelerate recovery, but their outcomes have not been systematically reviewed to evaluate pooled safety, efficacy, and clinical outcomes of these techniques. METHODS: A systematic review was conducted according to PRISMA guidelines, searching PubMed, Embase, and Scopus from inception through January 2026 using ("pars interarticularis" OR "spondylolysis") AND ("endoscopic" OR "percutaneous" OR "minimally invasive") AND ("repair" OR "fixation" OR "surgery"). English-language human studies reporting clinical outcomes were included. Extracted outcomes included radiographic data, pain and functional scores (VAS, ODI, SF-36), return to activity, complications, and reoperations. RESULTS: Of 140 identified studies, 5 met the inclusion criteria, comprising 47 patients (94 pars defects). Techniques included microendoscopic-assisted, irrigation endoscopic-assisted, tubular retractor-based, and fully percutaneous repair. Computed tomography-confirmed pars union was achieved in a pooled weighted mean of 84.4% (range, 77-100%) at 6-12 months. All studies reported significant pain and functional improvement, with a mean reduction in VAS of 5.5 points. Overall, 91.4% achieved good or excellent Macnab outcomes, and 93.6% returned to preinjury activity or sport. The complication rate was 6.4%, with no major neurologic, vascular, or infectious complications. Heterogeneity existed in surgical techniques and outcome reporting. CONCLUSIONS: Endoscopic and percutaneous minimally invasive direct pars repair is a safe, effective motion-preserving option for selected patients with symptomatic lumbar spondylolysis, though further prospective studies with standardized outcomes and longer follow-up are needed.