Facet joint distance measurement using digital tomosynthesis while standing

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• The zygapophyseal (facet) joint is vital for spinal stability and load transmission.
• Facet degeneration, linked to aging and osteoarthritis, can cause lower back pain due to decreased facet joint space.
• Current static imaging methods cannot assess dynamic changes in facet joint space under load, impacting the understanding of spinal segmental stability.

Purpose of the Study:

• To demonstrate the feasibility of a novel 3D digital tomosynthesis (DTS) method for measuring facet joint space.
• To assess the accuracy and reliability of DTS in quantifying facet joint space changes under physiological loading conditions.
• To evaluate the potential of DTS for characterizing dynamic facet joint behavior relevant to spinal stability.

Main Methods:

• Development and application of a novel 3D digital tomosynthesis (DTS) imaging technique.
• Measurement of facet joint space in supine and standing positions to simulate varying physiological loads.
• Comparison of DTS measurements with microcomputed tomography (micro-CT) reference values for accuracy assessment.
• Pilot in vivo study involving seven participants to evaluate dynamic loading effects.

Main Results:

• Facet gap measurements using DTS showed strong correlation (r=0.98) and high accuracy (<20 µm error) compared to micro-CT.
• The DTS method successfully detected changes in median facet joint space under physiological loading.
• Significantly larger median facet joint space was observed in the standing position compared to the supine position (p < 0.0001).

Conclusions:

• The novel 3D DTS method provides accurate and feasible measurement of facet joint space.
• This technique can characterize dynamic changes in facet joint space under physiological load, which is critical for assessing spinal stability.
• The DTS approach offers a valuable tool for clinical assessment of facet joint conditions, potentially improving diagnosis and management of lower back pain.