Tandem Spinal Stenosis: A Proposed Therapeutic Algorithm Based on a Systematic Review and Meta-Analysis

Tandem spinal stenosis (TSS) is characterized by stenosis in two or more noncontiguous spinal regions. Surgical management may involve simultaneous decompression or staged procedures; however, no universally accepted decision-making algorithm exists.

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. PubMed, Scopus, and EMBASE databases were searched for studies reporting outcomes of simultaneous and/or staged surgery for TSS. Fifteen studies were included in the qualitative review, and 12 were eligible for meta-analysis. Surgical strategies were compared based on postoperative functional outcomes.

A total of 1,006 interventions (604 staged and 402 simultaneous) were analyzed. Overall, significant postoperative improvement in Japanese Orthopaedic Association scores was observed (pooled SMD, 2.87; 95% CI, 1.88 to 3.86). Subgroup analysis demonstrated the greatest improvement with staged surgery using a cervical-first approach (SMD, 4.31; 95% CI, 3.87 to 4.76; I 2 = 0%), followed by simultaneous surgery (SMD, 2.65; 95% CI, 1.76 to 3.53). Lumbar-first staged surgery showed smaller and statistically negligible improvement (SMD, 1.94; 95% CI, -1.69 to 5.56). Complication rates were higher in older patients and in those with longer operative times and greater estimated blood loss.

Surgical strategy for TSS should be individualized. In the presence of myelopathy, staged surgery prioritizing cervical decompression is recommended. In the absence of myelopathy, simultaneous decompression may be considered in patients who can tolerate longer operative times. We propose a treatment algorithm to guide surgical decision-making based on symptom predominance, presence of myelopathy, and patient comorbidities.