Ulnar nerve compressionUlnar nerve compression

Michael Maru

Orthopaedic Postgraduate Teaching

23/04/07

Introduction Introduction

Second most common entrapment neuropathy M >F 5:1 Frequently bilateral Before 1959,it was thought to be posttraumatic ulnar palsy After 1959, Osborne called it tardy ulnar palsy referring to

idiopathic ulnar neuritis Feindel & Stafford in 1973 coined the term cubital tunnel

syndrome (CTS) Commonest cause of ulnar nerve compression is CTS

Relevant anatomyRelevant anatomy

Terminal portion of medial cord ( C8, T1) Supplied by post. ulnar recurrent arteryo Forearm : FCU, FDP, cutaneous ulnar 4/5th

digits

o Hand: All motor o Palmaris brevis o Interossei o Lumbricals (3rd & 4th) o Flexor pollicis brevis o Adductor polliciso Hypothenar muscles

Branches: all distal to elbowBranches: all distal to elbow

Anatomy Anatomy Sunderland 1987;

Described internal topography of ulnar nerve Sensory and intrinsics fibres superficial Motor fibres to FCU & FDP are deeply located Hence weakness of FCU/FDP not typically seen in ulnar nerve

neuropathy

Sunderland S: Nerves and nerve injuries . 2nd ed. New York, NY: Churchhill Livingston; 1987: 728-74

“Double crush” concept Proximal compression of nerve trunk may increase

vulnerability to distal compression This is due to disruption of axonal transport

Sites of compressionSites of compression

Elbow– Arcade of Struthers – Medial epicondyle– Olecranon groove– Cubital tunnel– Anomalous anconeus

– Flexor pronator aponeurosis

Sites cont…Sites cont… Guyons canal:

Ulnar tunnel syndrome Tunnel enclosed by piso-hamate ligament Commonly due to ganglion cyst, tumour,

aneurysm or fractured hook of hamate Involvement of dorsal sensory branch

indicates compression proximal

to Guyon’s canal

Risk factorsRisk factors Trauma;

Acute, chronic or repetitive Anaesthesia and bed-ridden

patients Pressure with flexed elbow

(occupational)

Bony deformities; Arthritis (RA) Shallow groove Valgus deformity

Soft tissue masses Ulnar nerve prolapse Alcoholism Diabetes

Clinical presentationClinical presentation Paraesthesia; ring and little

finger (night) Pain ( Elbow) Weakness of grip, dropping

objects Clawing

More in distal lesions “Ulnar paradox”

Hyperextension of MCPJ (lumbricals)

Flexion of IPJ (interossei)

Intrinsic muscle wasting

Classification Classification

McGowan;Types 1: recent, mild, intermittent dysaethesia

II: persistent dysaethesia, early motor loss

III: Marked atrophy and weakness

McGowan AJ. The results of transposition of the ulnar nerve for

traumatic ulnar neuritis. J Bone Joint Surg Br, 1950;32: 293-301.

Diagnosis Diagnosis

History & Examination Ask & look for risk factors Neurological examination of upper limb

Special provocation tests Elbow flexion test: supinate, flex elbow and hyperextend

wrist Froments sign : weak adductor pollicis Wartenburg sign: little finger adopts abducted posture “Making a wish” sign: unable to cross index over middle Tinels sign: tapping along the ulnar groove causes tingling to

ring and little fingers ( +ve in 24% normal popu)

Differential diagnosisDifferential diagnosis

Cervical root lesion/myelopathy Neck & Arm pain, UMN signs

Thoracic outlet syndrome Vascular anomalies Fatigue with arm overhead

Brachial plexus abnormalities Involvement of other nerves

Investigations Investigations

Radiographs Nerve conduction studies

• Conduction velocities < 50m/s

• Identify site of compression

Electromyography• Axonal degeneration

MRIUltrasound scan

ManagementManagement Conservative

• Indicated if paraesthesia is transient• Patient education about posture• NSAIDs for nerve irritation• Physiotherapy• Elbow extension splints

Treatment of ulnar nerve palsy at the elbow with a night splintSeror-P. Laboratoire d'Electromyographie, JBJS-Br. 1993 Mar. 75(2). P 322-7.

22 patients treated with night splint preventing elbow flexion beyond 60 degrees. Improvement of symptoms in every patient including 3 who had failed surgical decompression! Conclu: Nocturnal elbow flexion aggravates symptoms

Operative managementOperative management

Indications • Failure of conservative methods

• Persistent paraesthesia

• Progressive symptoms especially motor

Options• Decompression in-situ

• Decompression with transposition

Decompression in-situDecompression in-situ

Incision 8cm proximal and 6 cm distal to medial epicondyle

Osborne ligament incised to open tunnel Open or endoscopic May be combined with medial epicondylectomy

Decompression with Decompression with transpositiontransposition

May be indicated in:• Recurrence of symptoms after simple neurolysis

• Acute fracture ORIF ( prominent metalware)

• Elbow arthroplasty (scarring)

• Ulnar nerve repair

• Cubital valgus

• Arthritis with osteophytes formation

• Recurrent dislocation of nerve

Decompression with Decompression with transpositiontransposition

Anterior transposition to lengthen nerve and decrease tension

Can be submuscular, intra-muscular or subcutaneous

Held using fascio-dermal sling or suture

Transposition or not?Transposition or not? Cochrane Review; 5 RCTs, same conclusion

Simple decompression or subcutaneous anterior transposition of the ulnar nerve for cubital tunnel syndrome

NABHAN A et al ; The Journal of hand surgery 2005, vol. 30, pp. 521-524

Prospective randomised study; 66 patients, 32 had simple decompression, 34 had transposition. At 9 months , no significant difference in pain, sensory or motor deficits. Recommended simple decompression

Randomized, prospective study comparing ulnar neurolysis in situ with submuscular transpositionBiggs M, Curtis J; Neurosurgery 2006, Vol 58, issue 2, pg 296-304

RCT, 44 patients, 21 had neurolysis, 23 had transposition. Both procedures equally effective in objective neurological improvement. However, higher wound complications.in transposition group.Conclusion; Neurolysis in situ for idiopathic symptomatic ulnar nerve compression

Endoscopic or open?Endoscopic or open?

Endoscopic method becoming popular Thought to be less invasive, quick rehab No reported RCT Tsu-Min Tsai et al (1999)

85 elbows in 76 patients F/U of 32 months 42% excellent, 45% good, 11% fair,2% poor

Tsai TM, Chen IC, Majd ME: Cubital tunnel release with endoscopic assistance: results of a new technique. J Hand Surg [Am] 1999 Jan; 24(1): 21-9

Decompression at the wristDecompression at the wrist Zigzag incision Pisohamate ligament opened Identify and remove the cause Usually ganglion cyst (Sedon)

beware aneurysm!

Hence the need for appropriate

investigation before operating

Conclusion Conclusion

Commonest site of ulnar nerve compression is at the cubital tunnel in the elbow

Decompression in-situ (neurolysis) is recommended for idiopathic ulnar nerve neuropathy

Transposition should be considered in recurrent cases, arthritis and cubital valgus

Endoscopic release is the future trend.

Thank you

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