Bacteria: back pain, leg pain and Modic sign-a surgical multicentre comparative study

Area of Science:

• Spinal surgery
• Microbiology
• Radiology

Background:

• Cutibacterium acnes (C. acnes) has been implicated in painful degenerated discs, leading to suggestions for antibiotic treatment in lumbar disc herniation (LDH) and low back pain (LBP).
• The rise of multidrug-resistant bacteria necessitates strong scientific evidence for new antibiotic indications.

Purpose of the Study:

• To compare bacterial findings in degenerated discs of adults with LDH/LBP to non-degenerated discs in adolescents with scoliosis.
• To evaluate the association between bacterial findings and Modic changes on MRI.

Main Methods:

• Surgical samples from skin, wounds, discs, and vertebrae were cultured from 40 adults with LDH/LBP and 20 adolescent scoliosis patients.
• 16S rRNA-based PCR sequencing was used for DNA analysis of disc/vertebral samples.
• MRI findings, specifically Modic changes, were assessed preoperatively.

Main Results:

• Bacterial growth was similar in both groups (15%). C. acnes was the predominant species found.
• The majority of positive cultures originated from the skin or wound, not deep disc/vertebral tissue.
• No association was found between bacterial findings and Modic changes on MRI.

Conclusions:

• Bacterial presence in discs of adults with LDH may be due to contamination, as it mirrors findings in adolescent scoliosis patients.
• The similar prevalence of C. acnes in both groups, often linked to skin flora, challenges the notion of disc infection in LDH.
• Antibiotic therapy for LDH/LBP without clinical evidence of discitis/spondylitis warrants critical re-evaluation.