Cubital Tunnel Syndrome and Carpal Tunnel Syndrome: Current Concepts

David Moss, MD

Cubital Tunnel

Anatomy

H&P

EMG?

Non-op – splint/inj

SMUNT vs SQUNT vs ISUNT

Endoscopic

Carpal Tunnel

Anatomy

H&P

Fact or fiction?

Arises from C8-T1

Cubital Tunnel

Floor – elbow joint capsule

Walls – medial epicondyle and olecranon

Roof – Osbourne’s ligament

First branch is to the elbow joint

No branches in the brachium

Numb SF and half of RF

Grip weakness, intrinsic weakness

Positional exacerbation

Tinel’s test 23-34% + in normal

volunteers

EFT 10% + in normal

volunteers

Intrinsic strength

FDP SF and RF strength

Scratch collapse 99% PPV, 99% sensitive

C-spine exam

Adductor pollicis weakness & FPL compensation

• Similar to Froment’s, with MCP hyperextension

Wartenburg sign

Abduction of SF with attempted active extension due to unopposed EDQ action (ulnar insertion)

Clawing SF & RF (Duchenne’s sign)

more severe in low ulnar palsy

What to look for:

CV < 50 m/s

10 m/s delta slowing from contralateral side

20% amplitude reduction from contralat side

Shortcomings

Patient discomfort

~75% sensitive

Unclear location of nerve compression

Cervical?

Cubital tunnel?

Guyon’s canal?

Revision surgery

Not routinely recommended for “classic” CuTS

Some will obtain for a baseline measurement

Limited value unless prior fracture or suspicion of a mass

Anconeus epitrochlearis

Cubitus valgus

Activity modification

Avoid prolonged elbow flexion

Ergonomic workstation analysis

Night splinting in 45° extension (Gelberman)

Nerve glides and therapy

Mild symptoms (intermittent paresthesias)

42% resolution at 6 months

Moderate (no muscle wasting)

32% resolution at 6 months

False Hong et al. 2007

Medial epicondylectomy

Transposition

Subcutaneous - SQUNT

Intramuscular - IMUNT

Submuscular - SMUNT

In situ decompression - ISUND

Open

Endoscopic

High rate of nerve subluxation

Valgus instability

Bony tenderness

Of historic interest

SMUNT and IMUNT

Longer post-op immobilization to allow healing of the flexor/pronator mass

SQUNT

Shorter post-op immobilization

Relative contraindicated in very thin patients

Common if concommitant elbow trauma

Most data shows no difference in long term outcomes between SQUNT, IMUNT, AND SMUNT

Kose et al. Adv Ther 2007

Shi et al JHS 2011

Shortest operative time

Post-op immobilization is not necessary

Can be performed under local anesthesia

Endoscopic ISUND is trending

Higher patient satisfaction ratings compared to open ISUND in literature

More expensive

No difference! Macadam et al. JHS 2008

Callandro et al. Cochrane Database 2012

No difference between ISUND and transposition

No consensus on when to treat surgically versus conservatively

Most authors recommend transposition for frank subluxation

No consensus in the literature for treatment of perched ulnar nerve

63 yr old anesthesiologist c/o 6 month h/o medial elbow pain with occasional numbness to SF and RF. No c/o weakness.

No systemic disease or h/o trauma

PE:

+Tinel’s

+EFT

+ scratch collapse

Normal c-spine exam

No weakness or wasting

No subluxation

What is the next step?

I recommend activity modification, prescribe nighttime extension splint

Re-examine at 6-8 weeks

If no improvement then ISUND is offered

EMG is not routinely prescribed

No evidence that transposition is superior to simple decompression

Trend towards less invasive - ISUND

Unless frank ulnar nerve subluxation - SQUNT

Night pain

Tingling

Loss of dexterity and fine motor skills

Earrings

Buttons

Grip weakness

Women: Men = 3:1

Obesity

Diabetes

Hyperthyroidism

Pregnancy

Trauma

History

Physical examination

Nerve conduction test

Lalonde, Evidence based medicine: carpal tunnel syndrome. PRS 2014

Treatment of CTS, AAOS Clinical Practice Guideline Summary, 2008

Wrist flexion-carpal compression exam

82% sensitive

99% specific

Carpal tunnel (Durkan’s) compression test

87% sensitive

90% specific

MRI

Ultrasound

Nerve conduction studies

CT scan

73-100% sensitive

97.5% specific

Negative nerve test does not preclude positive surgical result

False

Splint in neutral is the most effective way to reduce neural pressure

Cortisone injection is acceptable for mild CTS

Acupuncture is equivalent to placebo

No literature to support splinting MCPs in extension

NSAIDs have not proven to be beneficial

Oral steroids have limited benefit

False

Large studies show no difference

Risk of adverse reaction to ABX > risk of infxn

Diabetics, TJA, stents, RA

True

18 days vs. 38 days

Improved scar sensitivity, pinch and grip at 3 months with ECTR

No long term difference

Critical element: complete division of the transverse carpal ligament regardless of he method

False

Post-op splint led to worse results in one study

No difference in most studies

No proven advantage or disadvantage of post-op therapy

73 yr old widow, lives alone, presents with 1 yr h/o nocturnal numbness in T, IF, MF. She c/o difficulty buttoning her blouse and putting in earrings.

Non-contributory PMH

PE:

Decreased sensation T, IF, MF to D2PD

+ Tinel’s test

- Phalen’s

+ CTCT

Thenar wasting

Normal c-spine

What is the next step?

I offer endoscopic CTR to expedite her return to independent living

EMG is not ordered in this scenario due to the clear diagnosis

Non-op treatment is not indicated in the setting of severe CTS (muscle wasting)