1. ENTRAPMENT
NEUROPATHIES OF
THE UPPER LIMB
Jerry Antony

2. • Entrapment neuropathy is caused by the direct pressure
on a single nerve.
• Symptoms & signs depend on which nerve is affected.
• Earliest symptoms to occur: tingling & neuropathic pain.
• Followed by reduced sensation or complete numbness
• Muscle weakness is noticed later, followed by muscle
atrophy.

3. Pathophysiology
COMPRESSION
VENOUS
OBSTRUCTION +
ISCHEMIA
ANOXIC
SEGMENT
NEURAL
EDEMA &
DILATATION
OF SMALL
VESSELS
EXACERBATION
OF ORIGINAL
COMPRESSION
CONT OF
VICIOUS
CYCLE
PERSISTENT
EDEMA +
ANOXIA/
HYPOXIA
FIBROSIS
IMPAIRMENT
OF SUPPLY
DEFICIENCY
OF VITAL
NUTRIENTS
FUNCTIONAL
IMPAIRMENT
PERMANENT
IMPAIRMENT
OF FUNCTION
IF LEFT
UNTREATED

5. MEDIAN NERVE
• 3 important compression neuropathies from distal to
proximal
CARPAL TUNNEL SYNDROME
ANTERIOR INTEROSSEOUS SYNDROME
PRONATOR SYNDROME

6. CARPAL TUNNEL SYNDROME
• Results from compression of the median nerve within the
carpal tunnel.
• Most common compression neuropathy in the upper limb.
ANATOMY
Cylindrical cavity connecting the volar forearm with the palm.
• Floor: transverse arch of carpal bones
• Medially: hook of hamate, triquetrum & pisiform
• Laterally: scaphoid, trapezium & fibro osseous flexor carpi
radialis sheath.
• Roof: proximally flexor retinaculum, transverse carpal ligament
over the wrist and aponeurosis between thenar & hypothenar
muscles distally.

7. CONTENTS:
• Tendons of flexor digitorum superficialis & profundus in a
common sheath
• Tendon of flexor pollicus longus in an independent sheath
• Median nerve

8. ETIOLOGY:
• DECREASE IN SIZE OF CARPAL TUNNEL
Bony abnormalities of the carpal bones
Acromegaly
• INCREASE IN CONTENTS OF CANAL
Forearm & wrist fractures (colle’s, scaphoid)
Dislocations & subluxations (scaphoid rotary subluxation, lunate
volar dislocation)
Post traumatic arthritis (osteophytes)
Aberrant muscles (lumbricals, palmaris longus, palmaris profundus)
Local tumours (neuroma, lipoma, ganglion, cysts, multiple
myeloma)
Persistent medial artery
Hyrertrophic synovium
Hematoma (hemophilia, anti coagulation therapy, trauma)

9. • NEUROPATHIC CONDITIONS
DM
Alcoholism
Double crush syndrome
Exposure to industrial solvents
• INFLAMMATORY CONDITIONS
Rheumatoid arthritis
Gout
Non specific tenosynovitis
Infections
• EXTERNAL FORCES
Vibration
Direct pressure

10. • ALTERATIONS OF FLUID BALANCE
Pregnancy
Menopause
Eclampsia
Thyroid disorders (esp. hypothyroidism)
Renal failure
Long term hemodialysis
Raynaud’s disease
Obesity

11. CLINICAL FEATURES:
• SIGNS : Tinel's sign, thenar atrophy, sensory changes in the
distribution of median nerve
• Tinel’s sign: percussing the
median nerve at the wrist.
• Phalen’s test:
Patient places elbow on table,
forearm vertical with wrist flexed.
Numbness & Tingling in median nerve
distribution occurs in 60 seconds in + ve cases.
• Reverse Phalen’s test:
Sustained extension of the wrist may also
aggravate the symptoms. Not a reliable test.

12. • TOURNIQUET TEST:
Inflating a BP cuff on the arm to a pressure above systolic
pressure will initiate symptoms (paraesthesia & numbness).
• DURKAN’S TEST:
Application of direct pressure on the carpal tunnel with either
pressure manometer or by thumb of the examiner for 30
seconds will produce the symptoms.
SENSORY TESTS
• Weber’s 2 point discrimination test:
Test is positive in about one-third cases.
• Semmes - Weinstein monofilaments:
Monofilaments of increasing diameters are touched to
palmar side of the digit until the patient can tell which
digit is touched.

13. INVESTIGATIONS:
• Electro diagnostic studies:
Most reliable confirmatory test.
Conduction time & latency for both sensory & motor conduction is
determined.
• CT & MRI:
If mass is suspected within the carpal tunnel
• LABORATORY TESTS: specific cause is suspected
Renal & thyroid function, RA factor, ESR, Anti nuclear antibody, uric
acid, blood sugars.
Radiographs: Wrist AP, Lateral, Carpal tunnel views. Useful in
detecting congenital anomalies, fractures, Calcific deposits or tumours
of carpal bones.
TREATMENT:
• NON OPERATIVE
• OPERATIVE

14. NON OPERATIVE:
Activity modification
NSAID’S
Splinting
Treating the underlying disease
Local steroid injections
OPERATIVE:
 OPEN CARPAL TUNNEL RELEASE
 ENDOSCOPIC CARPAL TUNNEL RELEASE
INDICATIONS:
Failure of non operative treatment
Weakness/atrophy of abductor pollicis brevis
Objective sensory changes
Electrophysiological evidence of thenar muscle denervation

15. OPEN CARPAL TUNNEL RELEASE:
• Incision & deeper dissection are performed ulnar to the
longitudinal plane between the ulnar border of the ring finger &
a point along the wrist crease noted by flexing the ring finger
against the palm.
• Transverse carpal ligament is divided proximally to distally.
• Complete demonstration of the recurrent branch of median
nerve should be performed.
COMPLICATIONS:
• Incomplete division of transverse
carpal ligament.
• Division of palmar cutaneous branch or
motor branch of median nerve.
• Injury to superficial palmar vascular arch.
• Reflex sympathetic dystrophy.
• Palmar hematoma.
• Loss of grip strength.

16. ENDOSCOPIC CARPAL TUNNEL RELEASE
Emerging technology for open decompression of the carpal
tunnel.
CONTRAINDICATIONS:
Co existent ulnar tunnel release.
Limited wrist & finger extension.
Tenosynovitis
Previous surgery

17. ANTERIOR INTEROSSEOUS SYNDROME
• Anterior interosseous branch of the median nerve
supplies the flexor digitorum profundus to the index finger,
flexor pollicis longus & pronator quadratus.
• Provides sensation to the volar aspect of carpus.
• POTENTIAL SITES OF COMPRESSION:
Fibrous bands of the flexor digitorum superficialis
Fibrous bands of the deep or superficial heads of the pronator
teres.
• LESS COMMMON CAUSES
Anomalous muscles
Enlarged / thrombosed vessels
Tumours
Enlarged bursae

18. CLINICAL FEATURES:
• Weakness of flexion in the IP joint of the thumb.
• Weakness of flexion in the DIP joint of index finger.
• No sensory loss
• Pain is exacerbated by exercise & relieved by rest.
• Number of cases occur due to a viral neuropathy.
TREATMENT
• INITIALLY: CONSERVATIVE
• SURGICAL: INDICATIONS
No resolution of symptoms
Severe symptoms
• SURGICAL EXPLORATION: Identification & division of the
offending structure.

19. PRONATOR SYNDROME
Anatomical sites of compression:
Below lacertus fibrosus
Between the 2 heads of pronator teres

20. CLINICAL FEATURES
• Ache or discomfort in the fore arm associated with
weakness or clumsiness of the hand.
• Numbness in the distribution of the median nerve.
• Night pain is not common.
• Phalen’s test & Tinel's sign: negative
• Difficult to demonstrate electrophysiological abnormality.

21. TREATMENT
• CONSERVATIVE:
NSAID’S
Splinting with the elbow at 90 degrees, slight forearm
pronation & wrist flexion.
• SURGICAL:
Exploration of distal 5 to 8 cm of the course of the
median nerve in the arm combined with its course in the
upper forearm.
Possible sites checked
Appropriate release is done.

22. ULNAR NERVE
• Ulnar nerve gets entrapped at 2 common sites:
At the elbow (cubital tunnel syndrome)
Guyon’s canal (ulnar tunnel syndrome)

23. CUBITAL TUNNEL SYNDROME
• Second commonest nerve entrapment of the upper limb
• ANATOMY: CUBITAL TUNNEL
Starts at the groove between the olecranon & the medial
epicondyle.
Tunnel is formed by a fibrous arch connecting the 2 heads of
the flexor carpi ulnaris & lies just distal to the medial
epicondyle.

24. CAUSES OF ENTRAPMENT
• ARCADE OF STRUTHER’S: Formed by superficial muscle
fibres of the medial head of triceps attaching to the medial
epicondyle ridge by a thickened condensation of fascia.
• Tight fascial band over the cubital tunnel.
• Medial head of triceps
• Aponeurosis of flexor carpi ulnaris
• Recurrent subluxation of ulnar nerve, results in neuritis.
• Osteophytic spurs
• Cubitus valgus following supra condylar fracture.

25. CLINICAL FEATURES
• Numbness involving the little finger & the ulnar half of the
ring finger.
• Hand weakness & clumsiness
• Tenderness over the ulnar nerve at the elbow.
• Tinel’s sign is positive: exacerbation of paraesthesia’s with
light percussion over the ulnar nerve.
• Advanced cases : clawing of the ring & little fingers

26. TREATMENT
• NON OPERATIVE: Early stages
Activity modification
Immobilization of the elbow in 30 degrees of extension, followed by
periods of mobilization with elbow padding.
• SURGICAL:
Decompression of the nerve by dividing of the basic offending
structure.
Anterior transposition of the ulnar nerve
Medial epicondylectomy

27. ULNAR TUNNEL SYNDROME
• Ulnar nerve is compressed as it passes through
GUYON’S canal in the wrist.
• Less common than entrapment of the ulnar nerve at the
elbow.

28. ANATOMY:GUYON’S CANAL
• ROOF: composed of palmar carpal ligament blending into
the FCU tendon attaching to the pisiform & the pisiohamate
ligaments.
• Medial wall : pisiform & pisiohamate ligament.
• Lateral wall: hook of hamate & some fibres of the transverse
carpal ligament.
• Ulnar nerve enters guyon’s canal accompanied by ulnar A &
Ulnar V.
• Guyon’s canal lies in the space between flexor retinaculum &
volar carpal ligaments.

29. • The anatomy of distal ulnar tunnel is divided into 3 zones.
• Zone 1:proximal to the bifurcation of the ulnar nerve &
consists of both sensory & motor fibres of the nerve.
• Zone 2: represents the motor branch of the ulnar N distal
to the bifurcation.
• Zone 3: represents the sensory branches of the ulnar
nerve beyond its bifurcation.

30. Clinical presentations:
• ZONE 1 LESIONS : Mixed sensory & motor loss.
• ZONE 2 LESIONS : Isolated motor deficit.
• ZONE 3 LESIONS : Isolated ulnar N sensory loss.
• Common Causes in zone 1 & 2: ganglions, fractures of
the hook of hamate.
• Zone 3: ulnar artery thrombosis
OTHER CAUSES:
• Malunited fracture of fourth/fifth metacarpal.
• Anomalous muscles
• Occupational trauma

31. INVESTIGATIONS
• X RAY : Oblique/carpal tunnel views
Delineate bony anatomy to diagnose hook of hamate fractures.
• MRI: Ganglia, space occupying lesions
TREATMENT
• Operative release of the canal by reflecting the FCU,
pisiform & pisiohamate ligament ulnarly.
• Distal deep fascia of the forearm below the wrist crease
should be released.
• Resection of any space occupying lesion
• Treatment of hook of hamate fractures.

32. RADIAL NERVE
• POSTERIOR INTEROSSEOUS NERVE SYNDROME
• RADIAL TUNNEL SYNDROME
• WARTENBERG’S SYNDROME

33. PIN SYNDROME
ANATOMY
Proximal to the elbow joint, the radial nerve branches into the
superficial radial nerve & the PIN.
The PIN travels around the radial neck and through the interval
between the 2 heads of the supinator muscle.
This opening which has an overlying compressive fibrous arch is
known as arcade of frosche.

34. Clinical features:
• Initially, presents with a dull ache in the proximal
forearm.
• Later, there is difficulty in extending the fingers & the
thumb.
Etiology:
 Ganglion cyst
 Proliferative synovitis (rheumatoid arthritis)
• Electro diagnostic testing may localize the site of
compression.
• Initially : observation & non operative treatment.
• Operative methods: exploration & appropriate division of
compressing structures.

35. RADIAL TUNNEL SYNDROME
• The PIN passes between the 2 heads of the supinator
muscle in the radial tunnel.
• Boundaries of radial tunnel
Medial: biceps tendon
Lateral : brachioradialis & extensor carpi
radialis longus & brevis tendons
Roof: brachioradialis
floor :deep head of the supinator muscle

36. • Pain is often acute & can mimic tennis elbow.
• Electrophysiological studies shows no abnormality.
• Treatment: non-operative: Activity modification, splinting,
NSAID’S & rest.
• Surgical decompression is often combined with lateral
epicondyle release.

37. WARTENBERG’S SYNDROME
• Compression of the superficial branch of the radial nerve
can occur most commonly as it exits from beneath the
brachioradialis in the forearm.
• Nerve can get trapped b/w the ECRL & the
brachioradialis, especially with pronation in the forearm.

38. ETIOLOGY
• Mass effect
• Direct trauma
Clinical Features:
• Numbness and / pain in the dorsal & radial aspects of the
hand.
• Positive Tinel's sign
• Symptoms can be further elicited by forceful pronation of
the forearm.
• TREATMENT
• Conservative: activity modification, NSAID’S, Steroid
injections, splinting & occupational therapy.
• Failure of conservative therapy: surgical exploration &
decompression.

39. Thank You