Laterality of lumbar disc herniation.

Area of Science:

• Orthopedics
• Neurosurgery
• Spine Surgery

Background:

• Lumbar disc herniation (LDH) is common in men aged 20-40, typically at L4/5.
• Left-right differences in LDH occurrence and characteristics are not well-documented.
• Understanding laterality may improve estimations of intervertebral disc mechanical load.

Purpose of the Study:

• To investigate and compare left- and right-sided lumbar disc herniation (LDH).
• To analyze differences in patient demographics, surgical parameters, and clinical outcomes between right- and left-sided LDH.
• To assess the relationship between age and the laterality of LDH.

Main Methods:

• Retrospective analysis of 2,899 surgical LDH cases from the Nagoya Spine Group database.
• Comparison of patient characteristics including age, LDH level, surgical technique, operative time, blood loss, hospital stay, and preoperative JOA score.
• Inclusion criteria required observable right- and left-LDH sides within a single vertebral segment.

Main Results:

• LDH occurred more frequently on the left (1541 patients) than the right (1358 patients).
• Patients with right-sided LDH were significantly older (mean 47.9 years) than those with left-sided LDH (mean 45.0 years).
• Right-sided LDH incidence increased with age, from 42.7% in patients aged 10-29 to 54.7% in those aged 70-89.

Conclusions:

• Left-sided LDH is more prevalent, but right-sided LDH demonstrates a higher incidence with increasing age.
• No significant differences were observed in sex, age distribution, LDH level, surgical parameters, or outcomes (JOA score, recovery rate) between right- and left-sided LDH.
• Further research into the biomechanical factors influencing LDH laterality is warranted.