Clinical outcome following decompression and short or long instrumented fusion in lumbar degenerative spinal stenosis. A prospective case-control analysis.

Objectives: There is limited data on the direct clinical comparison between short and long fusion following surgery for lumbar spinal stenosis. The hypothesis that regardless their baseline characteristics and morbidity, clinical outcome is similar in patients with lumbar stenosis treated with decompression plus posterior instrumented fusion in one or two versus three to five levels was tested.

Methods: Subjects were divided into Group A and Group B corresponding to stenotic pathology and instrumented fusion in one or two levels and three to five levels, respectively. Primary outcome measures at one year were the change in SF-36 physical component (PCS) and Oswestry Disability Index (ODI). Secondary outcome measures included the EuroQol-5D (EQ-5D), the Visual Analog Scale (VAS), the mental component (MCS) of SF-36 scale and the Zung Self-Rating Depression Scale.

Results: Seventy seven (77) patients were included (Group A, n = 42; Group B, n = 35). Patients in Group B were older, surgery lasted longer and intraoperative blood loss was greater than patients in Group A (p < 0.05). A significant clinical improvement was noted in both Groups on all scales (p < 0.01). Clinical outcome at one year was equally favorable in both Groups (p > 0.05). The evaluation of depression for Group A showed a significant improvement at one year (p = 0.02) compared to the preoperative status.

Conclusions: Older individuals are more likely to have multilevel stenosis and more co-morbidities and they were associated with longer instrumentation. However, complications are similar and clinical outcome is equally favorable compared to short instrumented fusion for fewer levels of disease.