1. Ulnar nerve compression
Michael Maru
Orthopaedic Postgraduate Teaching
23/04/07

2. 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

3. Relevant anatomy Terminal portion of medial cord ( C8, T1)
Supplied by post. ulnar recurrent artery
Forearm : FCU, FDP, cutaneous ulnar 4/5th digits
Hand: All motor
Palmaris brevis
Interossei
Lumbricals (3rd & 4th)
Flexor pollicis brevis
Adductor pollicis
Hypothenar muscles

4. Branches: all distal to elbow

5. Anatomy Sunderland 1987; “Double crush” concept
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:
“Double crush” concept
Proximal compression of nerve trunk may increase vulnerability to distal compression
This is due to disruption of axonal transport

6. Sites of compression Elbow Arcade of Struthers Medial epicondyle
Olecranon groove
Cubital tunnel
Anomalous anconeus
Flexor pronator aponeurosis

7. 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

8. Risk factors Trauma; Bony deformities; Soft tissue masses
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

9. Clinical 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

10. 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:

11. Diagnosis History & Examination Special provocation tests
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)

12. Differential 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

13. Investigations Radiographs Nerve conduction studies Electromyography
Conduction velocities < 50m/s
Identify site of compression
Electromyography
Axonal degeneration
MRI
Ultrasound scan

14. Management 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 splint
Seror-P. Laboratoire d'Electromyographie, JBJS-Br Mar. 75(2). P
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

15. Operative management Indications Options
Failure of conservative methods
Persistent paraesthesia
Progressive symptoms especially motor
Options
Decompression in-situ
Decompression with transposition

16. Decompression 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

17. Decompression with transposition
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

18. Decompression with transposition
Anterior transposition to lengthen nerve and decrease tension
Can be submuscular, intra-muscular or subcutaneous
Held using fascio-dermal sling or suture

19. 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. 
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 transposition
Biggs M, Curtis J; Neurosurgery 2006, Vol 58, issue 2, pg
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

20. 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

21. Decompression 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

22. 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.

23. Thank you ?