facet joint arthropathy-by dr ashok jadon

8/11/2019 Facet Joint Arthropathy-by Dr Ashok Jadon

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causing radiculopathy. Motor vehicle accidents or sports injuries may result in facet joint pain

secondary to hyper flexion, rotation, and distraction injuries.

Clinical presentation: Pain arising in cervical facet causes pain in upper or lower neck,

shoulder and also headache if upper cervical facets are involved. Thoracic facets causes pain in

lower neck, upper back and inter scapular area. Pain from lumbar facet joints causes low backpain with unilateral radiation to the buttock and posterolateral thigh (rarely below knee) which

may be exacerbated in extension and relieved with flexion. Pain frequently is also referred into

the groin, buttocks and hip. All lumbar levels are capable of producing groin pain, though it ismost common in the lower levels. Pain from the upper lumbar facets tends to extend into the

flank, hip, and upper lateral thigh, whereas pain from the lower lumbar levels is likely to

penetrate deeper into the thigh, usually in the lateral and posterior aspects. Infrequently, the L4-5

and L5-S1facet joints can provoke pain in the lateral calf, and rarely into the foot. Patients withosteophytes, synovial cysts, or facet hypertrophy also may manifest radicular symptoms. Pain is

often described as a "deep, dull ache" and maybe either unilateral or bilateral. On physical

examination increased pain with extension, tenderness to palpation over the affected joints, and

normal findings on neurologic examination. Facet joint pain is often worse after periods ofimmobilization (difficulty in getting up in morning due to stiffness) and improves with motion.

Hyperextension and the tilt test during examination and local tenderness on direct pressure overthe facet joint during fluoroscopic correlation can also be helpful for isolating symptomaticlevels. When the facets become pain generators, it is unusual that a single joint is involved.

Bilateral involvement has been reported in about 70% of cases and includes more than 3 regional

joints in many patients

Diagnosis:Diagnosis is mostly clinical as anatomical changes due to degeneration seen on x-

rays, CT or MRI does not correlate well with symptoms. Fractures or dislocation of facets jointsdue to injury and other symptomatic conditions like cysts pressing over nerves can be diagnosed

by imaging techniques (Table-1). Electrical stimulation of the medial branch nerves may also

assisted in identifying referral pain patterns. Confirmation that pain source is facet joint is done

by injection of local anaesthetic either into facet joint (intra articular injection) or by medialbranch blocks. However, No historical or physical examination findings can reliably predict

response to diagnostic facet blocks and there is high incidence of false positive (20-50%) and

false negative (11%) results. Use of serial blocks using lidocaine and bupivacaine had a highdegree of specificity (88%) but only marginal sensitivity (54%). Although a high specificity will

result in a low false positive rate, the low sensitivity predisposes patients to a false-negative

diagnosis. The reasons for false-positive facet blocks are, placebo-response, myofascial pain andepidural spread. In lumbar area the specificity of lumbar medial branch block (MBB) increases if

volume of local anesthetic is kept low (0.5 mL) and target point of injection is kept more caudad

(site midway between the upper border of the transverse process and the mamilloaccessory

ligament). There are also other Interventions that may reduce the incidence of false-positivelumbar facet blocks:

1. Placebo-controlled blocks, or comparative local anesthetic blocks.

2. Lower target point on the transverse process.


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block and more than 50% reduction in pain is taken as positive response. The response to medial

branch blocks has been reported to correlate with treatment outcome however, to avoid false-

positive response dual block (lidocaine and then bupivacaine) or placebo controls have beenadvocated before progressing to radiofrequency ablation.

Intra-articular Steroid Injections:Intra-articular injection of a steroid and a local anesthetic inthe facet joint is performed mainly for therapeutic purposes for relief of low back and neck pain.

The procedure may also be used for diagnostic purposes to establish the cause of pain. The joint

space can be entered directly or when direct access proves impossible or too difficult, an articularrecess can be targeted. CT guidance may be required if joint is severely degenerated and

osteophytes are present and there is inability to enter in to the joint during routine fluoroscopic

guided procedure. Once intra-articular access is confirmed (Fig-3) by contrast injection (0.2mL),

a combined solution of anesthetic and steroid can be injected. The most common long-actingsteroids include methylprednisolone, triamcinolone, and betamethasone. Intra-articular steroid

injections may be more effective when radiological evidence of joint inflammation and

degeneration is present. As with all steroid injections, attention should be given to the total

patient steroid dose during a 12-monthperiod, especially in patients with insulin-dependentdiabetes. Injection volume should also be limited to less than 2mL because intra-articular

injection may injure (rupture) joint capsule if large volume of drug is injected. Intra-articularinjection is still being used although outcomes from intra-articular injections limits conclusionsregarding their effectiveness. Recent reviews of available literature have concluded that facet

joint steroid injections have limited (level III) evidence of benefit it means either they are

ineffective, or have no benefit. However, there is general agreement among pain physicians thattherapeutic facet joint injection, per level affected, per year is reasonable if the patient has more

than 50% sustained relief for more than 3 months and RFA is contraindicated or refused by the

patient. Intra-articular facet steroid injections may also be considered if patient has posterior

fusion and access to both medial branch nerves is limited by hardware or bone graft material.

Radiofrequency ablation of Medial Branch Nerve: RFA of the medial branch nerve may be

considered to obtain prolonged pain relief when diagnostic medial branch block gives 50% to80% pain relief in patients without previous back surgery and whereas 35% to 50% pain relief in

patients with failed back surgery syndrome. The success of medial branch RFA is variable and

position of RF needle during nerve ablation is supposed to be a contributing factor. Therefore itis recommended that the ideal electrode position to be along the lateral neck of the superior

articular process rather than at the groove between the angle of the superior articular and

transverse processes.

Procedure:For RFA procedure, the patient is placed prone and appropriate levels are identified

under fluoroscope. The overlying skin is marked and area is cleaned and draped in sterile

fashion. Lidocaine is used for local anesthesia of the skin and soft tissues. Light sedation isoptional. At each level, a 22-ga 5- to 15-cm insulated 5- to 10-mm active-tip radio-frequency

cannula is inserted percutaneous and advanced under fluoroscopic guidance by using dorsal,

lateral, and oblique projections. Tip of needle should be directed to the base of the superiorarticular process. At lumbar level medial branch nerves lies between the intervertebral foramen

and the mamilloaccessory ligament. Aspiration is performed to exclude blood or CSF. Needle

placement is also confirmed with motor and/or sensory stimulation. Once needle position is


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confirmed mixture of preservative-free 2% lidocaine and steroid is injected at each level to

provide local analgesia during the heating process. The radio-frequency probes are then inserted

through the needles and heated in serial fashion either in the radio-frequency mode(80C for 1.5minutes) or pulsed mode at (42C for 2 minutes) (Fig-4 ). After the heating cycle has finished,

the needles are removed and sterile bandages are applied. Post-procedural examination and post-

sedation monitoring are performed and documented. Documentation of pretreatment and post-treatment pain perception, functional assessment, and analgesic/opiate requirements is must tomonitor outcome. Complications like bleeding, infection, or incomplete pain relief may occur.

Numbness or dysesthesias have been reported after RF denervation, but tend to be transient and

self-limiting.

A point to ponder:Diagnostic medial branch block is necessary to establish the diagnosis of

facet joint as pain generator in backache. It is advised that comparative block using short actinglidocaine followed by long acting local anaesthetic bupivacaine should be done as there is high

chances of false positive response. However, when determining the need for comparative LA

blocks due to relative risk for a false-positive or false-negative diagnostic block, the

complication rate of each diagnostic and RF procedure, the anticipated dropout rate, and costeffectiveness should be taken into account. Moreover, many patients respond with long-term

pain relief even to sham denervations therefore it is still not accepted as standard of care.

Review of efficacy: Uncontrolled trials have shown 18% to 63% success rate of intra-articular

steroid injection which could not be substantiated on randomized controlled trials. Intra-articular

steroid injections may provide intermediate-term relief to a small subset of patients with anactively inflamed facet joint. Many prospective and observational studies have supported this.

Opinion regarding therapeutic value of medial branch block with local anaesthetic with or

without steroid is divided. However, few patients may have long relief after medial branch blockwith local anesthetic irrespective of steroid is mixed or not. The results of medial branch RFA is

more definitive and sustained. Although, variable success have been claimed by various authors

the average relief is about 50% which last for 9months to 1year if conventional (thermal) RF is

done and maximum up to 6 months if pulsed RF is done. However, correct needle placement onthe target is must for good results.

Table-1 : Levels of degeneration of Facet Joints based on Magnetic Resonance Imaging

GRADE RADIOLOGIC FINDINGS

0 Normal zygapophysial joints (2-4 mm width)

1 Joint space narrowing or mild osteophyte formation or mild hypertrophy of the


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articular process

2 Narrowing of the joint space with sclerosis or moderate osteophyte formation or

moderate hypertrophy of the articular process or mild subarticular bone erosions

3 Narrowing of the joint space with marked osteophyte formation or severehypertrophy of the articular process or severe subarticular bone erosions or

subchondral cysts


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facet joint arthropathy-by dr ashok jadon

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