Understand Low back pain : Facet Joint Pain

Lumbar spines are composed of few structures which may cause low back pain. Spinal pathology usually involves few of those structures – not only one structure- making the diagnosis of low back pain sometimes tricky.

Conservative spinal treatment like Physical therapy, Chiropractor adjustments, Acupuncture sessions, Massage sessions, Meditation are not targeted treatments, meaning, same treatment may tackle all these structures at the same time.

The pattern of pain complaints and good physical examination assist to establish a “Differential Diagnosis” meaning, list of possible causative structure by order of possibility being the “The main generator of Pain”.

Interventional Pain Injections are targeted injections directed to a specific structure/s. These directed blocks have both diagnostic and therapeutic purpose. If you target a specific structure and got a good relief, so this structure is part of the pain process. If pain relief was 70-80%, so that structure is the main generator of pain and needs to be tackled to get the most pain relief. If you get pain 20-30% pain relief from targeting that structure, though it would be a pain generator but it is probably not the “main generator of pain”. Tackling that minor generator of pain is not essential but would also help to add more relief to patient if tackling the main generator is not giving enough relief.

There are few patterns of low back pain that help in diagnosis and tailoring a treatment plan;

I) FACET PAIN: Facet joint is a small joint the allows trunk extension and rotation movement. There is one facet joint on each side of spine at each level in lumbar spine. Facet joint pathology may be of degenerative “arthritis” process or injury of the lumbar spine during extension or rotation movement either due repetitive movements, or sudden lifting of heavy object, fall on the back especially with rotational movement.

Facet pain usually presents as an Axial pain than is;

1) limited to low back pain, on one or both sides,

2) not shooting down the legs below the knee level,

3) not accompanied by numbness and tingling down the leg,

4) might travel down the buttock/s to back of thigh/s,

5) but never beyond knee level,

6) getting worse with prolonged back extension like prolonged standing, sleeping flat on firm surface or twisting rotation of torso

7) might get better with bending forwards or stooping forwards.

After trying conservative treatment with no significant help, patient might try fluoroscopy guided Interventional Pain Injections or procedures. Physician usually start with,

a) Medial Branch Block (MBB): local anesthetic injection around a small nerve in spinal, different from the nerve root supplying the legs. This injection helps diagnostic purposes as it works for only few hours, but if it helps to eliminate significant amount of pain, that confirm the diagnosis of facet joint pathology. Few facets are targeted according to physical exam and MRI finding

b) Medial Branch Radio-Frequency Ablation (RFA): after a positive diagnostic MBB with significant but short term (only few hours) pain relief, physician may later target to the same Medial Branch nerves to “BURN” for a therapeutic long term pain relief usually about 3-4 months but may extend to 6-9 months in some cases. This “burning” does not involve any real heat or burning smell or sizzling!! Patient may only feel little warm or even nothing due to use of local anesthesia in burning site.

c) Facet Joint fusion: If patient did not get a satisfactory long term pain relief after one or few attempts of RFA or RFA started to give less sustainable pain relief due to arthritis got worse in those facet joints, your doctor may advice you to try a minimally invasive procedure to place a small device on the worst facet joint to fuse it via one inch skin opening. This device inhibits any pain producing movement at the targeted joint/s.

All above procedures are usually performed at an ambulatory same day surgical center under fluoroscopic guidance. Above procedures usually take about 6 minutes, 15 minutes, and 45 minutes respectively.