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Cubital tunnel syndrome
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CUBITAL TUNNEL SYNDROME:
Diagnosis and Management
OUTLINE• Anatomy• Epidemiology • Clinical exam• Treatment options• Submuscular transposition technique• OITE relevant stuff• Statistics:
– Effect size– Meta-analysis
EPIDEMIOLOGY• Ulnar nerve compression at the elbow:
Second most common compression neuropathy of the upper limb
• Incidence: 25 per 100000 person years– USA: 75000 cases annually – World-wide: 1.5 million cases
HISTORY
• Treated surgically for the first time in 1816 by Henry Early
TREATMENT OPTIONS• Simple decompression• Medial epicondylectomy• Ulnar nerve transposition
– Subcutaneous– Intramuscular– Submuscular
ULNAR NERVE TRANSPOSITION IS THE MOST COMMON PROCEDURE (Dutch survey data)
PRO SIMPLE DECOMPRESSION
• Preserves blood supply to ulnar nerve• Shorter operation• Earlier recovery because anatomical
location of ulnar nerve is preserved
PRO TRANSPOSITION
• Only transposition addresses the dynamic compression of the ulnar nerve seen with elbow flexion
ANATOMY
• Osbornes ligament:– Between FCU heads where ulnar nerve
enters forearm • Struthers arcade
– Fascial thickening in medial upper arm intermuscular septum where ulnar nerve enters dorsal compartment
OSBORNE’S LIGAMENT
ARCADE OF STRUTHERS
INCIDENCE: 13.5%
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!!!
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 min @ 120° flexion
reproduces symptoms)• Wartenberg’s sign • Fromment’s sign
AUTONOMOUS ULNAR NERVE SENSORY ZONE
• Most sensitive: 30 sec of elbow flexion in conjunction with direct pressure at ulnar nerve
93% SENSITIVITY
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!
Wartenberg’s Syndrome
• Sensory RADIAL nerve neuritis• Pain in radial distal forearm
FROMMENT SIGN
• Can’t adduct thumb (ulnar nerve)• Flexes thumb IP joint instead (median nerve)
Martin-Gruber Anastomosis
• Median to ulnar nerve anastomosis• Mainly motor fibers• Incidence: 17%• Therefore intrinsic weakness not always
present in cubital tunnel syndrome
Is Nerve Compression or Traction causing
Symptoms?
BASIC SCIENCE
CLINICAL DATA
CROSS SECTION
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
TRACTION IS THE PROBLEM - Simple decompression insufficient
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.
COMPRESSION IS THE PROBLEM
BETTER RESULTS WITH SIMPLE DECOPMPRESSION
BASIC SCIENCE: Traction is the problem!
CLINICAL DATA: Compression is the
problem!
PURPOSE OF THIS STUDY
• Less biased estimate of the true treatment effects
• Randomized data only
ELIGIBILITY CRITERIA
• No previous elbow trauma • No previous surgery • All patients failed initial
conservative treatment• Only randomized trials were
included to limit selection bias
DIAGNOSIS CONFIRMED BY EMG IN ALL CASES
STUDY IDENTIFICATION• Medline• Embase• Cochrane Database of Systematic Reviews • Cochrane Central Register of Controlled Trials • CINAHL • Annual meeting archives:
– Academy of Orthopaedic Surgeons (2004-2006) – American Association of Plastic Surgeons (2005-2006) – American Association of Neurological Surgeons (2001-2006) – American Society for Surgery of the Hand (2001-2006)
INDPENDENT SEARCH BY 2 OF US
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
OUTCOME PARAMETER
•Post-op EMG•Post clinical score
– McGowan score– Bishop score– Medical Research Council score
RESULTS
Screening
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
AUTHORS OF IDENTIFIED STUDIES WERE CONTACTED AND ALL PROVIDED
THE RAW DATA
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)
Pre-op Nerve Conduction Velocity
Post-op Nerve Conduction Velocity
Post-op Clinical Scores: Effect Size
WHAT IS EFFECT SIZE?
• A number that expresses a difference between two groups as a multitude of standard deviations
COHEN’s EFFECT SIZE
•Mild: 0.2•Moderate: 0.5•Large: 0.8
CLINICAL SCORE EFFECT SIZE BETWEEN AT AND SD: -0.04 (-0.36 to 0.28)
CONCLUSIONS
1. No difference in motor nerve conduction velocities and clinical outcome scores
2. Confidence intervals around the points of estimate are narrow probably excluding clinically meaningful differences
SINCE ULNAR NERVE TRANSPOSITION IS THE MORE
INVASIVE OF THE TWO PROCEDURES, THIS DATA
SUPPORTS THE USE OF SIMPLE DECOMPRESSION OF THE
ULNAR NERVE.
TREND TOWARDS BETTER RESULTS WITH TRANSPOSITIONBEWARE: INCLUDES NON-RANDOMIZED DATA!!!
MEDIAL EPICONDYLECTOMY
NO MAJOR DIFFERENCES, BUT HIGHER SATISFACTION AFTER MEDIAL EPICONDYLECOMY
BOTTOMLINE:NO CONSENSUS
ON BEST TREATMENT
ANTERIOR TRANSPOSITION INDICATIONS
• Prior injury to elbow• Revision surgery • Intra-operative ulnar nerve subluxation
SUBMUSCULAR / INTRAMUSCULAR TRANSPOSITION
TECHNIQUE
OITE Reminder:• Struther’s Arcade• Wartenberg’s sign
• Struther’s ligament
• Wartenberg syndrome
ULNAR NERVE
MEDIAN NERVE
RADIAL NERVE
CASE ID: 19
THANK YOU