Oral Presentation 51st International Society for the Study of the Lumbar Spine Annual Meeting 2025

Introduction: 

Tandem spinal stenosis (TSS) refers to spinal canal narrowing in two distinct regions of the spine. TSS can be an asymptomatic radiographic finding, or it can present with neurological symptoms. TSS has a complex clinical presentation, and there is no consensus on the optimal surgical strategy.

Methodology:  

The data of 236 patients were recorded for treatment of TSS with a minimum follow-up of 2 year. The patients were grouped based on the areas of stenosis as seen in a whole spine MRI, namely cervico-lumbar (Type A -184), cervico-thoracic (Type B -11), thoracolumbar (Type C -24) and cervico-thoracic & lumbar (Type D - 17). The criteria for diagnosis of TSS were cord compression and T2 signal intensity changes in cervical and thoracic, and canal width less than 8 mm in lumbar. In the sequence of surgical algorithm, clinical severity was taken as the prime factor followed by cord signal changes. In clinical severity, symptoms were given predominance over clinical signs. The algorithm followed this protocol – clinical severity > MRI features; myelopathy > radiculopathy; symptoms>signs; proximal> distal.

Results: 

Type A cervico-lumbar TSS was divided into four sub-types. Type A1-patients with clinical myelopathy without symptoms of LCS underwent cervical decompression alone (n=61). Patients with symptoms of LCS (Type A2) without clinical myelopathy underwent lumbar decompression alone (n=97). None in A1 and A2 groups developed symptoms due to the non-operated segments requiring second procedure at two year follow-up. Patients with predominant LCS symptoms with ONLY signs of myelopathy (Group A3, n=7) and Group A4 (n=21) with both myelopathy and claudication symptoms were treated by staged decompressions procedures.

Group B (n=11) had patients with myelopathy with compression at cervical and thoracic regions. They were sub-divided based on hand myelopathy signs and symptoms. If patients had both upper and lower limb myelopathy (Group B1), cervical decompression was done first (n=5) followed by thoracic decompression as second procedure. If patients had predominant lower limb myelopathy with absent hand myelopathy signs (Group B2, n=6), underwent thoracic surgery only even though they had cervical cord signal changes in MRI. Only one required cervical surgery later.

In Group C, 16 were treated by thoracic decompression based on signs of myelopathy. 10 cases required lumbar level surgery later. 4 patients who had only lumbar stenosis symptoms underwent lumbar decompression first as they had no myelopathy signs but 2 required thoracic level surgery at a later date when they developed signs of myelopathy. Group D had stenosis at all three regions and underwent decompression of the whole spine (n=17). There was significant improvement in mJOA score and ODI in all patients at minimum 2 years.

Conclusion: 

The present study is the first study to comprehensively classify all possible types of TSS and to give specific surgical strategies for each type, giving preference to the clinical presentation followed by radiological parameters. In groups A and B, clinical criteria were helpful in limiting the extent of surgery but in Type C and D, all stenotic levels required surgery irrespective of clinical status.