Elbow
Cubital Tunnel Syndrome
주관 증후군
Ulnar nerve compression at the cubital tunnel causing 4th-5th finger numbness and intrinsic muscle weakness
- How common
- Common
- Typical age
- Ages 30–60
What is it?
Ulnar nerve compression at the cubital tunnel (posterior groove of medial epicondyle) → sensory and motor dysfunction in ulnar nerve distribution
Commonly affected: Ulnar nerve (at cubital tunnel), hand intrinsics (interossei, hypothenar muscles, adductor pollicis)
How it develops
- Ulnar Nerve AnatomyUlnar nerve passes through cubital tunnel posterior to medial epicondyle, continues to forearm/hand
- Compression MechanismNerve tension increases with elbow flexion (9mm elongation). Repetitive positioning, trauma, osteophytes, cubitus valgus increase compression
- Neural IschemiaPersistent compression reduces intraneural blood flow → nerve damage
- Motor/Sensory DysfunctionUlnar nerve damage → 4th-5th finger sensory changes, intrinsic muscle weakness (possible claw hand)
Symptoms
- 4th-5th Finger NumbnessRing-little finger and ulnar palm numbness — ulnar nerve sensory distribution
- Worsening with Elbow FlexionSymptoms worsen with elbow flexion during phone use, driving, sleeping — increased nerve tension
- Intrinsic Hand WeaknessDecreased hand grip and pinch, difficulty picking cards, weak finger abduction/adduction
- Wartenberg SignLittle finger abduction — reflects weakness of 4th dorsal interosseous
How it is examined
- Elbow Flexion TestFull elbow flexion held for 60 seconds → reproduces 4th-5th finger tingling/numbness → Positive
- Tinel's Sign (Elbow)Tapping ulnar nerve posterior to medial epicondyle → electric shock sensation in ring-little fingers → Positive
- Froment's SignThumb flexion compensation when pinching paper → adductor pollicis weakness
- Muscle Strength TestingTest interossei (finger abduction/adduction), hypothenar, adductor pollicis strength
Imaging
Assess cubital tunnel osteophytes, elbow deformity (cubitus valgus)
- Perimedial epicondyle osteophytes
- Cubitus valgus deformity
- Joint damage if rheumatoid arthritis present
Identify nerve compression location and cause, pre-surgical planning
- Ulnar nerve thickening and T2 hyperintensity
- Compression cause within cubital tunnel (osteophytes, ganglion)
- Nerve subluxation
Non-surgical care
- Posture CorrectionAvoid elbow flexion posture — nighttime splint, sleep position modification
- Extension SplintNighttime elbow extension splint (30-45°) — prevents nerve tension during sleep
- Nerve Gliding ExercisesUlnar nerve gliding exercises to prevent neural adhesion
- Activity ModificationModify tasks requiring repetitive elbow flexion
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Failed conservative treatment 3-6 months, progressive motor weakness, abnormal nerve conduction
Procedures that may be discussed
- Medial epicondylectomy
- Simple decompression in situ
- Ulnar nerve anterior transposition — subcutaneous, intramuscular, submuscular
Outlook
Mild-moderate: 60-70% improvement with conservative treatment. Severe (motor weakness): 50-70% motor recovery with surgery