In degenerative lumbar spinal stenosis (DLSS) variability of symptoms according to the severity of stenosis is not well understood. Therefore, another factor that impacts functional outcomes of DLSS patients has been evoked: patient's comorbidities. The aim of this study was to investigate influence of comorbidities on clinical symptoms and functional outcomes in DLSS patients.

In this prospective study, patients treated for DLSS were included during 12 consecutive months. Both clinical and radiographic exams were required to confirm DLSS diagnosis. Epidemiologic, clinical and radiographic data were collected. Two questionnaires were used to assess functional outcomes: a specific score dedicated to lumbar stenosis consequences assessment (self-administered Beaujon questionnaire, SABQ) and a non-specific score (Short Form 36, SF-36). Four comorbidity scores were calculated: Cumulative Illness Rating Scale, Charlson index, Functional Comorbidity Index and Index of Co-Existent Diseases Correlations between functional and comorbidity scores were calculated.

250 patients were included (65.6±12 years). The four comorbidities scores were significantly correlated to total SABQ, as well as lumbar and radicular ischemia components. Best correlations were observed for cumulative illness rating scale and SABQ. Two factors were observed that significantly influenced the relationship between SABQ and cumulative illness rating scale: herniated disc and SF-36 general health perception.

This study highlighted that preoperative function is influenced by comorbidities in DLSS patients. Relationships existed between comorbidities and symptoms related to low back pain and neurogenic claudication, contrary to radicular pain. Therefore, comorbidities might impact the variability of patients’ outcomes. This finding should be part of the patient's preoperative information. Moreover, role of comorbidities on postoperative outcomes need to be investigated.