Biomechanical Characteristics of Kissing Spine During Extension Using a Human Cadaveric Lumbar Spinal Model

Area of Science:

• Biomedical Engineering
• Orthopedics
• Spinal Biomechanics

Background:

• Kissing spine syndrome, characterized by spinous process contact in the lumbar region, is common in older adults.
• Its biomechanical characteristics and relationship to lower back pain remain largely unexamined.
• Previous hypotheses suggested increased spinal rigidity and limited extension due to spinous process kissing.

Purpose of the Study:

• To investigate the biomechanical effects of kissing spine syndrome.
• To determine if spinous process contact during extension increases spinal flexural rigidity.
• To assess the impact of kissing spines on the range of motion and torque during spinal extension.

Main Methods:

• Three human cadaveric lumbar spine models (L4-L5) were utilized.
• Supraspinal/interspinous ligaments were removed, and spinous processes were approximated using dental resin to simulate kissing spines.
• Torque-range-of-motion (ROM) curves were measured using a six-axis material tester during flexion and extension.

Main Results:

• Maximum range of motion during extension was consistently lower than during flexion across all models.
• No sudden increase in torque was observed during the extension phase.
• The simulated kissing spine condition did not exhibit significant biomechanical alterations.

Conclusions:

• The study found no apparent biomechanical effects from kissing spinous processes.
• Contact between lumbar spinous processes appears to have minimal involvement in the onset of lower back pain.
• Further research may be needed to fully elucidate the etiology of lower back pain associated with this condition.