1. CUBITAL TUNNEL SYNDROME: Diagnosis and Management
Michael Zlowodzki MD
University of Minnesota
Department of Orthopaedic Surgery

2. OUTLINE Anatomy Epidemiology Clinical exam Treatment options
Submuscular transposition technique
OITE relevant stuff
Statistics:
Effect size
Meta-analysis

3. EPIDEMIOLOGY
Ulnar nerve compression at the elbow: Second most common compression neuropathy of the upper limb
Incidence: 25 per person years
USA: cases annually
World-wide: 1.5 million cases

4. HISTORY
Treated surgically for the first time in 1816 by Henry Early

5. TREATMENT OPTIONS
Simple decompression
Medial epicondylectomy
Ulnar nerve transposition
Subcutaneous
Intramuscular
Submuscular
ULNAR NERVE TRANSPOSITION IS THE MOST COMMON PROCEDURE (Dutch survey data)

6. PRO SIMPLE DECOMPRESSION
Preserves blood supply to ulnar nerve
Shorter operation
Earlier recovery because anatomical location of ulnar nerve is preserved

7. PRO TRANSPOSITION
Only transposition addresses the dynamic compression of the ulnar nerve seen with elbow flexion

8. ANATOMY Osbornes ligament: Struthers arcade
Between FCU heads where ulnar nerve enters forearm
Struthers arcade
Fascial thickening in medial upper arm intermuscular septum where ulnar nerve enters dorsal compartment

9. OSBORNE’S LIGAMENT

11. ARCADE OF STRUTHERS
INCIDENCE: 13.5%

14. STRUTHER’S LIGAMENT
MEDIAN nerve passes between ligament and humerus and can be compressed
Incidence: 1%
Can be associated with bony spur visible on xrays
Don’t confuse with Struther’s Arcade!!!

15. CLINICAL SIGNS
Sensory changes in ulnar nerve distribution (little+ring finger)
Intrinsic weakness (not always!)
Tinel’s sign at medial elbow
Elbow flexion test (3 120° flexion reproduces symptoms)
Wartenberg’s sign
Fromment’s sign

16. AUTONOMOUS ULNAR NERVE SENSORY ZONE

17. Most sensitive: 30 sec of elbow flexion in conjunction with direct pressure at ulnar nerve
93% SENSITIVITY

18. Wartenberg’s Sign
Ulnar abduction of 5th digit due to due to intrinsic weakness and unopposed abduction by extensor digiti minimi (because of it’s slightly ulnar insertion)
Don’t confuse with Wartenberg’s syndrome!

19. Wartenberg’s Syndrome
Sensory RADIAL nerve neuritis
Pain in radial distal forearm

20. FROMMENT SIGN Can’t adduct thumb (ulnar nerve)
Flexes thumb IP joint instead (median nerve)

21. Martin-Gruber Anastomosis
Median to ulnar nerve anastomosis
Mainly motor fibers
Incidence: 17%
Therefore intrinsic weakness not always present in cubital tunnel syndrome

22. Is Nerve Compression or Traction causing Symptoms?

23. BASIC SCIENCE
CLINICAL DATA

25. CROSS SECTION

26. Is Nerve Compression or Traction causing Symptoms?
Gelberman RH et al. Changes in interstitial pressure and cross-sectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow. JBJS Am. 1998

28. TRACTION IS THE PROBLEM - Simple decompression insufficient

30. LITERATURE REVIEW A systematic review based on non-randomized data
n=3024 patients in 60 studies
Potential selection bias: patients with less severe symptoms were treated more frequently with simple decompression
Bartels RH, Menovsky T, Van Overbeeke JJ, Verhagen WI. Surgical management of ulnar nerve compression at the elbow: an analysis of the literature. J Neurosurg. 1998;89:722-7.

31. BETTER RESULTS WITH SIMPLE DECOPMPRESSION
COMPRESSION IS THE PROBLEM

32. BASIC SCIENCE: Traction is the problem
BASIC SCIENCE: Traction is the problem! CLINICAL DATA: Compression is the problem!

34. Less biased estimate of the true treatment effects
PURPOSE OF THIS STUDY
Less biased estimate of the true treatment effects
Randomized data only

35. No previous elbow trauma No previous surgery
ELIGIBILITY CRITERIA
No previous elbow trauma
No previous surgery
All patients failed initial conservative treatment
Only randomized trials were included to limit selection bias

36. DIAGNOSIS CONFIRMED BY EMG IN ALL CASES

37. STUDY IDENTIFICATION INDPENDENT SEARCH BY 2 OF US Medline Embase
Cochrane Database of Systematic Reviews
Cochrane Central Register of Controlled Trials
CINAHL
Annual meeting archives:
Academy of Orthopaedic Surgeons ( )
American Association of Plastic Surgeons ( )
American Association of Neurological Surgeons ( )
American Society for Surgery of the Hand ( )
INDPENDENT SEARCH BY 2 OF US

38. METHODS Duplicate assessment of methodological quality (Detsky scale)
Duplicate data abstraction independently by two of us
Assessment of heterogeneity (Hedges & Olkin)
Assessment of publication bias
Random effects model for pooling data
Outcome parameters converted to effect sizes

39. Post-op EMG Post clinical score OUTCOME PARAMETER McGowan score
Bishop score
Medical Research Council score

40. RESULTS

41. Screening

42. STUDY CHARACTERISTICS
4 studies identified
2 studies: simple decompression versus submuscular ulnar nerve transposition (n=117)
2 studies: simple decompression versus subcutaneous ulnar nerve transposition (n=218).
Total of 335 randomized patients, 327 of whom were followed up (98%).
Sample sizes: 47 to 152
Average age: 51 years
65% males

43. AUTHORS OF IDENTIFIED STUDIES WERE CONTACTED AND ALL PROVIDED THE RAW DATA

44. SEVERITY OF SYMPTOMS
Majority of patients with moderate or severe symptoms
Dellon grade (II or III)
Pre-operative Medical Research Council grade (avg. of 4.3 on 1-7 scale)
Pre-op EMG (avg. NCV of 35 m/s)

45. Pre-op Nerve Conduction Velocity
Post-op Nerve Conduction Velocity

46. Post-op Clinical Scores: Effect Size

47. WHAT IS EFFECT SIZE?
A number that expresses a difference between two groups as a multitude of standard deviations

49. Mild: 0.2 Moderate: 0.5 Large: 0.8 COHEN’s EFFECT SIZE
CLINICAL SCORE EFFECT SIZE BETWEEN AT AND SD: (-0.36 to 0.28)

50. CONCLUSIONS
No difference in motor nerve conduction velocities and clinical outcome scores
Confidence intervals around the points of estimate are narrow probably excluding clinically meaningful differences

51. SINCE ULNAR NERVE TRANSPOSITION IS THE MORE INVASIVE OF THE TWO PROCEDURES, THIS DATA SUPPORTS THE USE OF SIMPLE DECOMPRESSION OF THE ULNAR NERVE.

52. TREND TOWARDS BETTER RESULTS WITH TRANSPOSITION
BEWARE: INCLUDES NON-RANDOMIZED DATA!!!

53. MEDIAL EPICONDYLECTOMY

55. NO MAJOR DIFFERENCES, BUT HIGHER SATISFACTION AFTER MEDIAL EPICONDYLECOMY

57. BOTTOMLINE: NO CONSENSUS ON BEST TREATMENT

58. ANTERIOR TRANSPOSITION INDICATIONS
Prior injury to elbow
Revision surgery
Intra-operative ulnar nerve subluxation

59. SUBMUSCULAR / INTRAMUSCULAR TRANSPOSITION TECHNIQUE

75. OITE Reminder: Struther’s Arcade Wartenberg’s sign Struther’s ligament
Wartenberg syndrome
ULNAR NERVE
MEDIAN NERVE
RADIAL NERVE

76. CASE ID: 19

77. THANK YOU