Therapeutic genicular nerve blocks for chronic knee pain

Ian Zhao, Ph.D.

July 26, 2018

Genicular Nerve

Blocks

May be used for several purposes

o To determine the source of pain

o To predict how pain will respond to long-term treatments

o To treat painful acute conditions

o For short-term pain relief after some surgeries/procedures

o For anesthesia during some procedures, such as finger surgery

and foot surgery

Are also used to treat chronic pain by some providers

o Peripheral nerve blocks are being used to treat chronic pain

o The practice is controversial

Peripheral nerve blocks

2

Genicular Nerve

Blocks

64400 – trigeminal nerve

64402 – facial nerve

64405 - greater occipital nerve

64408 – cranial (vagus) nerve

64410 – upper spinal (phrenic) nerve

64413 – cervical plexus

64415 – brachial (arm) nerve bundle

64417 – underarm (axillary) nerve

64418 – suprascapular nerve (collar bone)

64420 – intercostal nerve (rib)

64421 – multiple rib nerves

64425 – ilioingubal iliohypogastric nerves

(groin)

64430 – pudental nerve (external genital)

64435 – paracervical nerve (uterine)

64445 – sciatic nerve

64447 – femoral nerve

64448 – thigh nerve

64449 – lumbar plexus nerve bundle,

posterior approach

64450 - Injection, anesthetic agent; other

peripheral nerve or branch

64455 – plantar common digital nerve

64461 – paravertebral block - thoracic

G9770 - Peripheral nerve block (new)

CPT and HCPCS codes for PNBs

3

Genicular Nerve

Blocks

On peripheral somatic nerve blocks for long-term treatment

ASA: the American Society of Anesthesiologists;

ASRA: the American Society of Regional Anesthesia and Pain Medicine

Rosenquist et al., 2010. Anesthesiology; 112:1–24

A Survey by the American Society of Anesthesiologists

4

N Strongly Agree

Agree Equivocal Disagree Strongly Disagree

ASRA 170 15.3% 30.6% 34.7% 15.3% 4.1%

ASA 298 17.4% 28.2% 34.6% 17.1% 2.7%

Genicular Nerve

Blocks

Practice Guidelines for Chronic Pain Managemento An Updated Report by the American Society of Anesthesiologists Task

Force on Chronic Pain Management and the American Society of

Regional Anesthesia and Pain Medicine – 2010

o Recommendation for blocks - Peripheral somatic nerve blocks

should not be used for long-term treatment of chronic pain

Rosenquist et al., 2010. Anesthesiology; 112:1–24

Treatment guidelines

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Genicular Nerve

Bocks

Therapeutic genicular nerve block (TGNB) for chronic

knee pain

o Exclusions

Diagnostic genicular nerve block

Treating painful acute conditions

Perioperative analgesia

Anesthesia for surgery/procedures

Genicular nerve ablation is outside the scope

o It will be addressed in an HTCC topic: “Peripheral nerve

ablation for lower limb pain”

Is TGNB effective and safe for chronic knee

pain?

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Genicular Nerve

Blocks

The genicular nerves injected

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SMG

IMG

SLG

Common peroneal nerve Tibial nerve

Genicular Nerve

Blocks

Cochrane Database of Systematic Reviews

o None

Hayes’ database o Genicular nerve blocks for knee pain (Search & summary, Hayes, Inc. 2015,

updated 2017)

PubMedo Two (2) RCTs

o Two (2) case studies

The evidence – therapeutic genicular nerve block

for chronic knee pain

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Genicular Nerve

Blocks

Outcome F/U RCTs N Results/Conclusion Quality

RF neurotomy of GN vs. GN block (After TKA)

Pain, function

(OKS, KSS),

AE, disability,

QoL (SF-36),

analgesic use

3, 6 and

12

months

Qudsi-

Sinclair

2016

28 No sham control; poor design and data analyses; “as

treated” analysis instead of ITT; high differential attrition

rate > 10%

The authors showed statistically significant reduction in

pain (NRS) and an improvement in joint function during

the first 3 to 6 months and concluded that no difference

found compared to GN block in pain and function.

The changes in NRS and function scales, however, were

so small that they were not clinically important. For

example, the mean NRS value at the baseline was 6.43

(±1.56) for the GNB group. The value dropped to 5.30

(±1.80) at 3 months and 5.50 (±3.51) at 6 months post

treatment. The differences in the NRS scores compared

to the baselines were 1.1 and 0.9, respectively. Overall

we are unable to draw any conclusion from the RCT

because of the low quality of the study.

●○○○

Very low

RCT on therapeutic GN blocks

9

Qudsi-Sinclair, S., E. Borrás-Rubio, J. F. Abellan-Guillén, M. L. Padilla del Rey, and G. Ruiz-Merino. 2017. Pain Practice, 17: 578-88.

Genicular Nerve

Blocks

Outcome F/U RCTs N Results/Conclusion QualityGNB with local anesthetic vs. local anesthetic + corticosteroid (Knee OA patients)

VAS; Oxford

knee score

(OKS)

1, 2, 4

and 8

weeks

Kim 2018 48

The VAS scores were significantly lower in the lidocaine

plus TA group than that in the lidocaine alone group at 2

weeks and 4 weeks after GNB. The authors concluded

that when combined with a local anesthetic and

corticosteroid, GNB can provide short-term clinically

significant pain relief (up to 2 weeks). However, the

clinical benefit of corticosteroid administration was not

clear in comparison with local anesthesia alone (1 week).

Given the potential adverse effects, corticosteroids might

not be appropriate as adjuvants during a GNB for chronic

knee OA

●●●○

Moderate

RCT on therapeutic GN blocks – cont.

10

Kim, D. H., S. S. Choi, S. H. Yoon, S. H. Lee, D. K. Seo, I. G. Lee, W. J. Choi, and J. W. Shin. 2018., Pain Physician, 21: 41-51.

Genicular Nerve

BlocksKim et al. 2018

11

TA = triamcinolone

Genicular Nerve

BlocksKim et al. 2018

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Genicular Nerve

Blocks

Summary

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The evidence regarding genicular nerve block is scant

Some evidence showed that GNB may provide short-

term pain relief (one week with lidocaine alone and up to

2 weeks with lidocaine plus steroid)

The effectiveness of this procedure on chronic knee pain

has not been established

The safety of repetitive anesthetic/steroid injections is

unproven

Genicular Nerve

Blocks

Payer Policy Note

CMS No NCD identified on the CMS website

Aetna Not covered for cluneal, ganglion, genicular, and obturator nerve blocks for

chronic pain or for repetitive peripheral nerve blocks for chronic non-malignant

pain

2018

Blue Cross

Blue Shield

Florida

Nerve block injection of the genicular nerve for the treatment of chronic knee

pain is considered experimental or investigational. The available scientific

evidence remains insufficient to permit conclusions concerning the effect of

this procedure on net health outcomes.

4/15 2018

Anthem Genicular nerve blocks and genicular nerve ablation are considered

investigational and not medically necessary for the treatment of chronic knee

pain, including but not limited to any of the following:

Degenerative joint disease;

Osteoarthritis of the knee;

As a treatment prior to knee replacement;

As a treatment following knee replacement;

As a treatment for individuals who are not candidates for knee

replacement surgery

3/29/2018

Selected payers’ policy on therapeutic genicular

nerve blocks

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Genicular Nerve

Blocks

Coverage decision: Not Covered (Effective date: xx/xx/2018)

o Genicular nerve block for treating chronic knee pain is not a covered

benefit.

o The knee joint is innervated by the articular branches of several nerves

including the femoral, common peroneal, saphenous, tibial and

obturator nerves. These articular branches around the knee joint are

known as genicular nerves.

o Genicular nerve block for treating chronic knee pain is controversial.

The effectiveness of the procedure on relieving chronic knee pain is not

established. The safety of repetitive anesthetic/steroid injections to the

genicular nerves is unproven.

Therapeutic genicular nerve block for chronic

knee pain – draft coverage decision

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Genicular Nerve

Blocks

Upper extremity blocks Lower extremity blocks

• Interscalene block• Supraclavicular block• Infracalvicular block• Axillary block • Intercostal nerve block• Supascapular nerve block • Ulnar nerve block• Median nerve block• Radial nerve block• Wrist nerve block

• Lumbar plexus block• Femoral nerve block• Fascia iliaca block• Obturator nerve block• Cluneal nerve blocks• Genicular nerve blocks• Sciatic nerve block• Popliteal block• Saphenous nerve block • Adductor canal block• Ankle block• Digital nerve block

Peripheral nerve blocks

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Genicular Nerve

BlocksPeripheral nerve blocks – cont.

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Nerve blocks of the scalp, neck and trunk

• Scalp block• Cervical plexus block• Intercostal nerve block• Thoracic paravertebral nerve block• Interfascial plane blocks• Transverse abdominis plane (TAP) block• Rectus sheath block• Ilioinguinal and iliohypogastric nerve

block• Transversalis plane block• Pudental and paracervical blocks

• Greater occipital nerve block• Lesser occipital nerve block• Auriculo-temporal nerve block• Supra-trochlear and supraorbital

nerves block• Spheno-palatine ganglion• Trigeminal nerve block (for headaches)• Ganglion impar block• Dorsal rami blocks