23 April 2007 RVI

Median Nerve Median Nerve Compression Compression syndromessyndromes

Median Nerve Median Nerve Compression Compression syndromessyndromes

Jeff Auyeung SpR FreemanJeff Auyeung SpR Freeman

23 April 2007 RVI

Content• Anatomy Median

Nerve• Pronator Syndrome• Anterior

Interosseous Nerve Syndrome

• Carpal Tunnel Syndrome

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Anatomy•Formed by 2 cords anterior to 3rd part of axillary artery

•Crosses Brachial artery from lateral to medial

•Lies medial to brachial artery in cubital fossa

•Passes between 2 heads of PT

•Lies between FDS and FDP then deep to flexor retinaculum

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XXXX Pronator SyndromeXXXX Pronator Syndrome

XXXX Anterior InterosseousXXXX Anterior Interosseous SyndromeSyndrome

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Pronator SyndromeSites of Compression• Supracondylar

process• Ligament of

Struthers• Bicipital aponeurosis• Between two heads

of pronator teres• Under origin of FDS

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Pronator SyndromeSymptoms:

• Forearm pain

• Hand numbness

• No night pain

Signs:• Resisted elbow

flexion with supinated forearm (bicipital aponeurosis)

• Resisted forearm pronation with elbow extended (PT heads)

• Isolated long finger PIPJ Flexion (FDS)

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Pronator SyndromeInvestigation

• Xray Elbow

• EMG/NCT

Treatment

• Splint/NSAIDs

• Release all potential sites of compression

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Anterior Interosseous Nerve Syndrome

• Characterised by motor loss without sensory involvement

• Muscles affected: FDP(radial half), FPL and Pronator Quadratus

• Beware bilateral cases - ?Parsonage-Turner syndrome

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Anterior Interosseous Nerve Syndrome

Sites of compresion• Fibrous bands in

PT• FDS origin• Enlarged bicipital

bursa• Gantzer’s muscle

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Anterior Interosseous Nerve Syndrome

• OK sign to test FPL and FDP

• Beware Isolated FPL rupture (Mannerfelt-Norman Syndrome)

• Pronation in max elbow flexion for PQ

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Anterior Interosseous Nerve Syndrome

23 April 2007 RVI

Anterior Interosseous Nerve Syndrome

Investigation

• EMG/NCT

Treatment

• Splint elbow at 90°/NSAIDs

• Release all potential sites of compression

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23 April 2007 RVI

Carpal Tunnel Syndrome-

Epidemiology• Most common peripheral nerve

compression syndrome • F>M• 43 to 74/100’000 decompression in

UK• Plus countless conservatively

treated

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Carpal Tunnel Syndrome –

Aetiology/Pathophysiology

• Increase pressure in Carpal tunnel ( 8mm vs 90mm Hg)• Ischaemia• Focal demyelination

• Risk factors: DM, RA, OA, Hypothyroidism wrist trauma, obesity, pregnancy

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Carpal Tunnel Syndrome –

Work• Prescribed disease if

related to use of vibrating tools

• Vibrating tool = more than 2 fold increase in risk

• Keyboard and computer work not risk for CTS

• Palmer KT, Harris EC, Coggon D.Carpal tunnel syndrome and its relation to occupation: a systematic literature review. Occup Med (Lond). 2007 Jan;57(1):57-66. Epub 2006 Nov 2

• No relationship between work and CTS

• Except “work that involves very cold temperatures (possibly in conjunction with load and repetition) such as butchery “

• Falkiner S, Myers S When exactly can carpal tunnel syndrome be considered work-related? ANZ J Surg. 2002 Mar;72(3):204-9.

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Carpal Tunnel SyndromeDiagnosis

• History and Exam (structured? – 85-100%)• Tinel’s ( 38-62%/57%), Phalen’s (77-86%/ 48%)

• Neurophysiology (?worse in men)

• Kamath V, Stothard J. A clinical questionnaire for the diagnosis of carpal tunnel syndrome. J Hand Surg [Br]. 2003 Oct;28(5):455-9. Erratum in: J Hand Surg [Br]. 2004 Feb;29(1):95..

• Gunnarsson LG, Amilon A, Hellstrand P, Leissner P, Philipson L. The diagnosis of carpal tunnel syndrome. Sensitivity and specificity of some clinical and electrophysiological tests. J Hand Surg [Br]. 1997 Feb;22(1):34-7.

• Padua L, Padua R, Aprile, Tonali P. Italian multicentre study of carpal tunnel syndrome. Differences in the clinical and neurophysiological features between male and female patients J Hand Surg [Br]. 1999 Oct;24(5):579-82.

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Carpal Tunnel SyndromeManagement - Conservative

• Oral Meds• Vit B6• Steroid injection(?

Most useful in reversible causes/holding measure)

• Splint - ? Positions ? Rigidity

Likely to fail:• 50+years• > 10/12 symtoms• Constant

paraesthesia• Atrophy of APB• +ve Phalen’s

Giele H. Evidence-based treatment of carpal tunnel syndrome. Current Orthopaedics 15, 249-255

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Carpal Tunnel Syndrome

Management - Surgical• Open CTR• Endoscopic CTR• Limited CTR• Lengthening of

Flexor Retinaculum

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Carpal Tunnel Syndrome

Open Release• Beware motor branch

• Reconstruction vs. Lengthening

• 24% increase in volume(AP)

• 96% Satisfaction• Pinch and grip strength

return 6-12 weeks

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Carpal Tunnel SyndromeEndoscopic

• Uniportal vs Two portal technique

• Leave palmar skin and fat alone, not disturbed thenar and hypothenar muscles

• Faster recovery

• No Difference by 12 weeks

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Carpal Tunnel SyndromeOutcome

• >80% satisfied (?meaning)• Boston Carpal Tunnel Questionnaire• Scar tenderness• Pillar pain• Weakness• Slower return to work in manual

worker

23 April 2007 RVI

Thank you!Thank you!Thank you!Thank you!