An educational overview from OrthOpinions. Not case-specific and not medical advice for any particular patient.
What are facet joints, and why do they cause pain?
The facet joints (also called zygapophyseal or “z-joints”) are small paired joints at the back of every level of the spine. Each pair guides motion between two adjacent vertebrae and, together with the disc in front, forms a three-joint complex. Like any synovial joint, facets can develop osteoarthritic changes, capsular inflammation, and pain after injury or with age. Facet-mediated pain is a common and under-recognized source of neck pain and low back pain, especially in older adults, after motor-vehicle collisions with rotational or extension mechanisms, and in patients with degenerative spondylosis on imaging.
Clinical evaluation and diagnostic uncertainty
Facet pain has no single pathognomonic finding on exam or imaging. The clinical pattern typically includes axial (midline or paraspinal) pain worse with extension, rotation, and prolonged standing, with referral into the buttock or thigh from the lumbar facets, and into the shoulder or occiput from the cervical facets. It is usually NOT true radicular pain: it does not follow a dermatome and is not reproduced by nerve-root tension tests. Imaging findings such as facet hypertrophy, effusion, or synovial cysts are supportive but not diagnostic; asymptomatic degenerative facet changes are extremely common on MRI. The most rigorous confirmatory test for facet-mediated pain remains a diagnostic medial branch block (MBB) with a small volume of local anesthetic on the medial branches of the dorsal ramus that innervate the target joint.
Conservative care
Conservative management is first-line for most patients. Reasonable initial measures include:
- Activity modification to reduce extension and rotational loading of the painful segment.
- Structured physical therapy focused on core stabilization, hip and thoracic mobility, and posture retraining.
- Short courses of NSAIDs when appropriate for the patient, with attention to cardiovascular, renal, and gastrointestinal risk.
- Weight management, sleep, and general reconditioning, all of which meaningfully affect axial spine pain outcomes.
- Adjuncts such as heat, topical agents, and short-term manual therapy, chosen on a per-patient basis.
Most facet-mediated pain responds to a fair trial of conservative care over three weeks to three months. Escalation is considered when function does not improve and the clinical pattern still points to the facet joint.
Interventional injections
When conservative care has been given a fair trial and the exam suggests facet-mediated pain, image-guided interventional options are considered. The two most common are:
- Intra-articular facet injection — a small dose of local anesthetic (with or without steroid) placed inside the facet joint under fluoroscopic guidance. Useful in selected cases; the diagnostic value is limited by the small joint volume and by spread outside the capsule.
- Diagnostic medial branch blocks (MBBs) — targeted anesthesia of the medial branches that innervate the joint. Modern practice typically requires two positive blocks (a “dual block” protocol) to select patients likely to benefit from radiofrequency ablation. Concordant, time-limited relief after each block is the key finding.
Injections are diagnostic and therapeutic tools, not cures. The evidence for durable pain relief from steroid injections alone at the facet joint is modest and inconsistent; their most reliable role is helping identify the pain generator.
Radiofrequency ablation (RFA)
When two properly performed diagnostic MBBs give concordant, time-limited relief and function improves during the anesthetic window, radiofrequency ablation of the medial branches is a reasonable next step. RFA uses heat to interrupt the small medial branch nerves that carry pain from the target facet joints. Well-selected patients often experience meaningful pain relief for approximately six to eighteen months; because the nerve regenerates, RFA can be repeated. Reported benefits, durability, and complication rates depend heavily on patient selection, image guidance, needle technique, and the number of levels treated. RFA is not appropriate for radicular pain, discogenic pain, or non-facet mechanical pain, and its evidence base is stronger in the lumbar and cervical spine than in the thoracic spine.
Evidence-based indications and honest limits
The stronger indications for interventional facet care are: axial pain of at least several weeks’ duration; a clinical pattern consistent with facet mediation; failure of a reasonable conservative program; and concordant relief on properly performed diagnostic blocks. The weaker indications are: pain with prominent radicular features; unexplained neurological deficits; suspicion of infection, tumor, or fracture; or an unclear anatomic target on imaging. In those settings further evaluation is warranted before any procedure is scheduled.
When further evaluation is warranted
Red flags that prompt urgent or specialty referral include new weakness, bowel or bladder dysfunction, saddle anesthesia, unexplained weight loss, fevers, night pain, a history of cancer or immunosuppression, trauma with suspected fracture, and progressive neurological signs. These findings do not describe facet pain and should not be attributed to it without imaging and, when indicated, laboratory or specialty workup.
Related educational articles
This is the hub article for our facet joint cluster. Related material published on OrthOpinions:
- Cervical versus lumbar spine numbering — why the labels on a facet workup can mislead
- Treating facet-joint pain: intra-articular injections and radiofrequency ablation
- Medial branch blocks — what they are, which levels matter, and when they explain a headache
- The facet joints: what they are and why they matter in neck and back injury cases
- Radicular pain and referred pain are not the same thing
- Why an early MRI and a late MRI can tell different stories
Educational only. Not a substitute for individual medical evaluation and treatment. Questions or comments, or a topic you would like us to address in a future edition? Contact us through our website: OrthOpinions.
