Abstract
BACKGROUND: Congenital lumbar facet joint defect is a rare congenital developmental disorder with only a few reported cases in the literature, primarily affecting the L5-S1 segments. This study reports the first case of a defect in the left L3 inferior articular process; and presents a review of the existing literature on the subject, proposes a classification system, and validates the inter-observer and intra-observer reliability of this classification system. CASE PRESENTATION: A 14-year-old boy presented to our orthopedic clinic with persistent lower back pain for 1 month. Imaging analysis, including CT scans, 3D reconstruction, and MRI, revealed a congenital lumbar facet joint defect at the L3 level, which has not been reported. Conservative treatment resulted in a significant improvement in his symptoms, and he is currently under follow-up care. CONCLUSION: Congenital defect of the lumbar facet joint is a rare spinal condition. This article reports the first patient with a defect in the left L3 inferior articular process and conducts a comprehensive literature review, proposing a classification of articular process defects into five types. The two most common types are Types B and C. We have demonstrated that this system is reliable and reproducible and have described the treatment of each type.