NIPH Clinical Trials Search

Microplastic in lumbar spine tissue removed during surgery and their relationship to inflammation and spinal degeneration

Basic Information

Recruitment status	Pending
Health condition(s) or Problem(s) studied	lumbar spinal canal stenosis or lumbar intervertebral disc herniation
Date of first enrollment	09/02/2026
Target sample size	80
Countries of recruitment
Study type	Observational
Intervention(s)

Outcome(s)

Primary Outcome

Association between the presence of microplastics in ligamentum flavum and intervertebral disc tissues (particle count per gram) and the degree of intervertebral disc degeneration at the target lumbar level(s) on preoperative MRI (e.g., Pfirrmann classification).

Secondary Outcome

Association between microplastics in ligamentum flavum and intervertebral disc tissues and preoperative MRI findings, including: presence and type of Modic changes, ligamentum flavum thickness, and spinal canal cross-sectional area. Association between microplastic burden and the expression levels of genes related to intratissue inflammation, fibrosis, and extracellular matrix degradation, assessed by qPCR. Differences in transcriptomic profiles according to microplastic burden, including genome-wide gene expression patterns and enriched pathways identified by RNA sequencing (e.g., inflammation, oxidative stress, fibrosis). Association between microplastic burden and patient background characteristics, such as age, sex, BMI, smoking history, diabetes, and other relevant factors.

Key inclusion & exclusion criteria

Age minimum	>= 18age old
Age maximum	Not applicable
Gender	Both
Include criteria	Eligible participants must meet all of the following criteria: Patients who are diagnosed with lumbar spinal canal stenosis or lumbar intervertebral disc herniation at the Department of Orthopaedic Surgery, Shinshu University Hospital, and are scheduled to undergo lumbar decompression surgery (e.g., laminectomy, laminotomy, etc.) and/or lumbar discectomy (herniotomy). Patients aged 18 years or older at the time of enrollment. Patients who have undergone preoperative lumbar MRI, including at minimum T1-weighted and T2-weighted sagittal images and T2-weighted axial images. Patients who are able to receive sufficient explanation of the study purpose and procedures, and who are capable of providing written informed consent voluntarily based on their own free will.
Exclude criteria	Participants meeting any of the following criteria will be excluded: Patients with a prior history of surgery at the lumbar level(s) of interest (i.e., revision surgery). Patients with infectious spinal disease (e.g., spondylitis/vertebral osteomyelitis, discitis) or an apparent systemic infection. Patients with active systemic inflammatory disease (e.g., rheumatoid arthritis) in whom assessment of local tissue inflammation and degeneration is considered difficult. Patients for whom, at the time of surgery, it is determined that the minimum required amount of tissue (ligamentum flavum and/or intervertebral disc) for microplastic analysis and RNA analysis cannot be obtained. Any other patients deemed unsuitable for study participation by the principal investigator or co-investigators (sub-investigators).