This study aims to evaluate the effectiveness of prolotherapy using 5% dextrose compared to steroid and saline injections in patients with lumbar facet joint-related low back pain. The study is designed as a randomized, double-blind clinical trial conducted in a tertiary physical medicine and rehabilitation center. Participants will be randomly assigned to receive one of the three treatments. Clinical outcomes including pain intensity, functional status, and physical performance will be assessed at baseline, 1 month, and 3 months. The results of this study may help determine the short-term effectiveness of prolotherapy as a treatment option for chronic low back pain.

Lumbar facet joint osteoarthritis is a significant contributor to chronic low back pain and is associated with functional limitation and reduced quality of life. Interventional treatment options such as corticosteroid injections are commonly used; however, alternative approaches such as prolotherapy have gained attention due to their potential regenerative and neuromodulatory effects.

This study is a prospective, randomized, double-blind clinical trial designed to compare the effectiveness of 5% dextrose prolotherapy with steroid and saline injections in patients with chronic low back pain predominantly related to lumbar facet joint osteoarthritis. A total of 60 patients with symptoms lasting at least three months and inadequate response to conservative treatment are included. Participants are randomly allocated into three groups (1:1:1) using a computer-generated block randomization method.

All participants undergo ultrasound-guided bilateral facet joint injections at L2-3, L3-4, L4-5, and L5-S1 levels with a standardized volume per joint. Outcome measures include pain intensity assessed by the Visual Analog Scale (VAS), functional status evaluated using the Oswestry Disability Index (ODI), and physical performance tests such as the Fingertip-to-Floor Test, 6-Minute Walk Test, and Milgram test. Assessments are performed at baseline, 1 month, and 3 months.

The primary objective of this study is to evaluate the short-term clinical effectiveness of prolotherapy compared to steroid and placebo injections in lumbar facet joint-related low back pain.

Inclusion Criteria:

Adults aged 40-70 years Chronic low back pain lasting at least 3 months Inadequate response to at least 2 months of conservative treatment Predominantly axial low back pain aggravated by lumbar extension and rotation Absence of radicular symptoms No objective neurological deficits on physical examination

Clinical findings consistent with facet-mediated pain, including:

Localized facet joint tenderness Positive Kemp (lumbar extension-rotation) test Supportive positive Milgram test MRI evidence of lumbar facet joint osteoarthritis (L2-3 to L5-S1), including degenerative changes such as joint space narrowing, osteophytes, subchondral sclerosis, or facet hypertrophy

Exclusion Criteria:

• Significant lumbar disc herniation with nerve root compression Central canal or foraminal stenosis Vertebral fractures Inflammatory spinal diseases (e.g., spondyloarthritis) Predominant discogenic or vertebrogenic pain Neurogenic claudication Spinal deformities Objective neurological deficits Systemic inflammatory or neurological disorders Severe comorbid conditions that may affect functional outcomes Previous lumbar spinal interventions or injections Pregnancy Any other condition that may interfere with study participation or outcome assessment

Individual participant data (IPD) may be shared upon reasonable request, subject to institutional policies and ethical considerations.

Allocation concealment was achieved using identical opaque syringes labeled with participant codes. Syringes were prepared by an independent assistant who was not involved in outcome assessment or data analysis. Participants, care providers, investigators, and outcome assessors were blinded to group allocation throughout the study.