The Role of Cutibacterium Acnes in the Development of Degenerative Lumbar Intervertebral Disc Disease and the Clinical Effect of Microdiscectomy

The project is divided into retrospective and prospective parts. The retrospective part will consist of data processing and analysis using our large cohort of patients enrolled during the previous studies. The prospective part will include a) patient enrollment, b) preoperative data collection, c) perioperative tissue collection, d) microbiological examination, e) postoperative follow-up visits, and f) data management and statistical analyses.

Retrospective data processing and analysis For the retrospective part of the project, the investigators plan to use the C. acnes database stored at the Department of Neurosurgery, St. Anne's University Hospital, Brno, Czech Republic. This database contains 1200 anonymized adult patients with symptomatic lumbar disc herniation scheduled for microdiscectomy between 2015 and 2024. These patients were enrolled during the research project entitled "Presence of the low-virulence bacterium Propionibacterium acnes in the intervertebral disc tissue as a cause of chronic back pain". Each patient signed informed consent forms before enrolling in this study, enabling future data analyses. According to our preliminary review, at least 400 patients of the retrospective cohort have completed epidemiologic, MRI, microbiological, and clinical data. The epidemiological data include age, gender, disc herniation relapse, epidural steroid injection before the surgery, body mass index (BMI), the lumbar segment of herniation, type of herniation, and physical workload. The clinical data include microbiological findings from perioperatively collected disc tissue, preoperative spinal MRI, preoperative and postoperative pain intensity according to the visual analog scale (VAS), and functional disability for low back pain quantified by the Oswestry Disability Questionnaire (ODQ). Although the data is available, no hypotheses between C. acnes positivity and clinical outcomes have yet been tested on the dataset. Therefore, in this part of the project, microbiological findings will be studied together with radiological changes in preoperative MRI and clinical status before and after surgery.

Prospective data cohort

Patient enrollment - the investigators plan to enrol at least 400 patients with lumbar disc herniation indicated for microdiscectomy at the Department of Neurosurgery, Faculty of Medicine, Masaryk University and St. Anne's University Hospital, Brno, Czech Republic. Patients indicated for lumbar microdiscectomy will be prospectively screened, and those who pass the inclusion and exclusion criteria will be asked to sign the Informed Consent form to be enrolled in the study.

Preoperative data collection - baseline epidemiological and clinical data such as age, gender, disc herniation relapse, epidural steroid injection before the surgery, body mass index (BMI), the lumbar segment of herniation, type of herniation, and physical workload will be collected from each patient. Degenerative changes in the intervertebral discs and adjacent spinal structures will be evaluated on MRI as part of a standard preoperative examination. Clinical data will be obtained during the preoperative clinical exam and from patients in the form of questionnaires, including a numerical scale for leg and back pain, the Oswestry questionnaire evaluating the impact of low back pain on activities of daily living, and the Short Form quality of life questionnaire - 36 (SF- 36) to examine the quality of life before surgery.