Lumbar Facet Joints Injection

Chronic capsulitis

Causes and findings:
• Osteoarthritis or traumatic capsulitis, ankylosing spondylitis
• Spondylolysis/spondylolysthesis
• Unilateral low back pain, sometimes with dull vague aching down leg
• Painful limitation in the capsular pattern - most: loss of extension; less: loss of both side flexions; least: loss of flexion
• In younger patients with spondylolysis, often most painful movement is combined extension with side flexion to the painful side

Equipment:
Syringe - 1ml
Needle - 22G 3-3.5 inches (75-90mm) spinal
Kenalog 40 - 40 mg
Lidocaine - Nil
Total volume - 1 ml

Anatomy:
The lower lumbar facet or zygaphophyseal joints lie lateral to the spinous processes - approximately one finger width at L3, one and a half at L4 and two fingers' width at L5. They cannot be palpated but are located by marking a vertical line along the centre of the spinous processes and horizontal lines across between each process. The posterior capsule of the joint is found by inserting the needle the correct distance for that level laterally on the horizontal line.

Technique:
• Patient lies prone on small pillow to aid localization of the spinous interspace
• Identify and mark one or more tender levels
• Insert needle at first selected level vertically down to capsule
• Aspirate to ensure needle point is not intrathecal
• Deposit solution into and around capsule
• Withdraw needle and repeat at different levels if necessary

Aftercare:
Patient avoids excessive movement while maintaining activity. Abdominal strengthening and mobilizing exercises should be performed regularly. Occasional mobilization and hamstring stretching will help to maintain flexibility.

Comments:
If the capsule is not found immediately, gently 'walk' needle around bone until a hard end-feel is reached.

Alternative approach:
Some practitioners perform injection of the lumbar facets under fluoroscopy, but they can be safely reached in the above manner provided the end-point of the needle on bone is reached. This approach is more cost effective.