Nerves

Anomalous Innervations

1.  Richie-comeau

 

Site

- ulna to median in palm

- provides motor to the thenar muscles

- ulna dominate hand

- may be due to RC anastomosis

 

Clinical significance

- carpal tunnel syndrome with no thenar atrophy

 

2.  Martin-Gruber 

 

Site

- median to ulna in forearm

- provides motor function to hypothenar eminence

 

Clinical significance

- cubital tunnel syndrome with no hypothenar atropy

- may be due to MG anastomosis

 

 

 

Brachial Plexus

Anatomy

Composition

 

C5 - T1

- prefixed: C4 (more common)

- post fixed: T2

 

Roots (3 Branches / LSD)(Interscalene)

Trunks (1 Branch)(Posterior Triangle)

Division (Clavicle)

Cords (5,5,3)(Axillary Artery)

 

Nerve roots

 

Formed by ventral and dorsal nerve rootlets

- in foramen

- DRG has cell bodies of sensory nerves

- rupture proximal to DRG indicates preganglionic

 

Run between scalenius anterior and medius

 

Branches

- long thoracic nerve (C5/6/7)(serratus anterior)

- nerve to subclavius (C5/6)

- dorsal scapula nerve (C5)(rhomboids)

 

T1 sympathetic ganglion close to T1 nerve root

- frequently injured together

 

Trunks

 

A.  Upper 

- C 5/6

- merger is Erb's point

- where SSN exits

- injury: SSN, axillary, MCN (lose SS, IS, deltoid, biceps)

 

B.  Middle

- C7

 

C.  Lower

- C8/T1

 

Branches

- suprascapular nerve (C5,6) from upper trunk

 

Divisions

 

Trunks divide into anterior and posterior

- behind clavicle

 

Cords

 

A.  Posterior cord (5)

- all three posterior divisions

- C5 - T1

- posterior to axillary artery

 

Branches

- radial is terminal branch

- axillary

- upper and lower subscapular

- thoracodorsal

 

B.  Lateral cord (3)

- anterior divisions of upper and middle trunk

- C5/6/7

- lateral to axillary artery

 

Branches

- MCN lateral to artery

- lateral branch of median nerve / runs across artery

- lateral pectoral

 

C.  Medial cord (5)

- anterior division of lower trunk

- C8 / T1

- medial to axillary artery

 

Branches

- medial median

- medial pectoral

- MCNA, MCNFA (medial cutaneous nerve of arm and forearm)

- ulna nerve is terminal branch (runs medial to artery)

 

Sensation

 

Roots / ASIA

 

Peripheral nerves

 

Supraclavicular region  C4

 

Regimental patch C5

- axillary nerve

 

Radial forearm C6

- LCNFA / MCN

 

Dorsal first web space C6

- radial nerve

 

Thumb and thenar eminence C6

- median nerve

 

Middle finger C7

- median nerve

 

Little finger C8

- ulnar nerve

 

Ulnar forearm T1

- MCNFA

 

Medial arm T2

- MCNA

 

Motor

 

Nerve roots / ASIA

 

C5 / deltoid / bicep

C6 / wrist extensors

C7 / tricep

C8 / MF FDP

T1 / interossei

 

Adjacent nerves

 

Trapezius (CN Xl)

- patient shrugs shoulders against resistance

 

Branches from roots

 

Rhomboid (C5)

- dorsal scapular nerve

- patient retracts scapula

- examiner uses hand to palpate

 

Serratus anterior (C567)

- long thoracic nerve

 

A.  Patient pushes against wall

- observe for winging

- patient protracts shoulder against resistance 

 

B. Some pateints won't be able to get arm up to wall

- raise arm for them

- get them to push arm away

 

Branches from the trunks

 

Supraspinatus (C5)

- suprascapular neve

- patient tries to initiate abduction of the arm from the side

 

Infraspinatus (C5)

- suprascapular nerve

- patient tries to externally rotate shoulder with arm by side

 

Branches of the posterior cord (C5-T1)

 

Deltoid (C5)

- axillary nerve

- patient abducts arm against resistance

 

Latissimus Dorsi (C7)

- thoracodorsal nerve

- patient adducts horizonal arm against resistance

 

Subscapularis

- upper and lower subscapular

 

Radial nerve

 

1.  Triceps (C78)

- patient extends elbow against resistance

 

2.  Brachioradialis (C6)

- patient flexes the elbow with forearm pronated

 

3.  ECRL (C67)

- radial nerve

- extend IF against resistance

 

4.  ECRB (C67)

- PIN

- extend MF

 

5. Wrist extension (C67-ECR, C67-ECU)

- radial and posterior interosseous nerve

- patient extends wrist

 

5.  Supinator (C6)

- patient supinates forearm in extension

 

6.  EDC (C8)

- PIN

- patient extends MCPJ

 

7.  ECU (C67)

- PIN

- extend wrist

 

8.  Extensor pollicis longus (C7)

- PIN

- patient extends thumb IPJ against resistance

 

Branches of the lateral cord (C5,6,7)

 

Pectoralis major (clavicular fibres) (C6)

- lateral pectoral nerve

- patient pushes arm forwards with arm horizontal

 

Biceps (C56)

- musculocutaneous nerve

- patient tries to flex elbow with forearm supinated

 

Lateral median nerve

 

1.  PT (C6)

- pronate in flexion

 

2.  FCR (C6)

- wrist extension

 

Branches of the medial cord (C8 / T1)

 

Pectoralis major (sternocostal fibres) (C7,8)

- medial pectoral nerve

- patient places hand on hip and pushes in

 

Medial branch median nerve

 

Flexor digitorum profundus (C8)

- AIN

- patient makes fist and resists extension of index finger

 

Flexor pollicis longus (C8)

- AIN

- patient flexes distal phalanx of thumb against resistance

 

Abductor pollicis brevis (TI)

- patient abducts thumb at right angles to palm against resistance

 

Ulna nerve

 

Flexor carpi ulnaris (C8)

- patient flexes wrist against resistance

 

Flexor digitorum profundus (C8)

- patient makes fist and resists extension of little finger

 

Interossei (TI)

 

 

Examination

Diagnostic Issues

 

Supraclavicular

- nerve root patterns of sensation and motor disturbance

 

Infraclavicular

- peripheral nerve root pattern / cord

 

Supraclavicular preganglionic

- dorsal scapular / long thoracic / suprascapular nerves injured

- Horner's

- lack of sensation supraclavicular

- no tinel's

 

Supraclavicular postganglionic

- + Tinels

- tender posterior triangle

 

Look

 

Aids

 

Front

 

Horner's 

- suggests C8/T1 root avulsion

 

Posterior triangle swelling / bruising

 

Wasting deltoid / biceps / Pecs

 

Wrist drop

 

Side

 

Hand on head

- axillary scars

 

Back

 

Trapezius

Deltoid

Supraspinatus/ Infraspinatus

Static winging

 

Feel

 

Palpate post triangle

- tenderness

- supraclavicular post ganglionic

 

Tinel's in post triangle

- supraclavicular post ganglionic

 

Sensation

 

Ask patient about sensory loss

 

Supraclavicular C4 

- suggests preganglionic injury

 

Axillary nerve C5 

 

LCNF C6 musculocutaneous

 

SRN C6 (1st dorsal webspace) 

 

C6 median n (thumb)

 

C7 median n (MF)

 

C8 ulnar n (LF)

 

C8 MCNF m cord (med forearm)

 

T1 MCNA m cord

 

T2 ICBN

 

Motor

 

Trapezius 

- function of accessory nerve important

 

Roots / From Behind

 

Rhomboids

- shoulders back

- DSN C5

 

Rhomboid Testing

 

Serratus anterior

- push shoulder forward

- LTN C5-7

 

Suggest preganglionic

 

Trunk

 

Suprascapular Nerve (C5)

- supraspinatous

- infraspinatous

 

Front / Nerve Root innervation

 

Deltoid 

- C5

- axillary / posterior cord

 

Bicep

- C5

- musculocutaneous / lateral cord

 

Left biceps wasting

 

Tricep

- C7

- radial / posterior cord

 

Wrist extension

- C6

- radial / posterior cord

 

Finger flexion

- C8

- median / medial and lateral cord

 

Finger abduction

- T1

- ulna nerve / medial cord

 

Decide if fits root pattern

- Otherwise consider cord injury

 

Cords

 

Post Cord

- axillary nerve (deltoid + T minor)

- radial nerve

- subscapularis

- lat dorsi TDN C7 (hand on hip or cough)

 

Medial Cord

- medial median (FDP, FPL, AbPB)

- medial pectoral (sternal head)

- ulna nerve (interossei, LOAF)

- MCNA / MCNFA (decreased sensation medially)

 

Lateral Cord

- lateral median (FCR, PT)

- musculocutaneous (biceps, sensation lateral forearm)

- lateral pectoral (clavicular head)

 

Reflexes

 

Biceps C5

Triceps C7

BR C6

 

4Cs

 

Cephalad joint - Neck

Concealed - axilla

Circulation

Collagen

 

Injury

Classification Leffert "OCRO"

 

I Open

 

II Closed

 

A  Supraclavicular 

- Preganglionic / Avulsion of Roots

- Postganglionic / Rupture of Trunks

 

B Infraclavicular

- cords & branches

 

C.  Post anaesthetic

 

III Radiation / Other

 

Tumour

Iatrogenic e.g. patient positioning

Other

 

IV Obstetric

 

A Erb C5/6

B Klumpke C7/8 T1

C Mixed

 

Narakas Rule of 7's

 

70% MVA

70% of these MBA

70% associated injuries

70% supraclavicular

70% root avulsions 

70% C8/T1 involvement

70% persistent pain

 

Aetiology

 

MBA most common

 

Gunshot Injury

- deficit 2° nerve concussion

- usually improves

- observe for 3 /12

- explore if no improvement / large residual deficit

 

Position of arm

- abducted above horizontal (lower lesion)

- abducted below horizontal (upper lesion)

 

Associated Injuries

 

Axillary / subclavian artery 10-20%

 

Fracture humerus / clavicle / scapula / ribs

 

Dislocations GH / AC / SC joints

 

Rotator cuff tears

 

Patterns

 

Supraclavicular preganglionic (nerve root patterns)

Supraclavicular postganglionic (trunks)

Infraclavicular (cords)

 

Can be mixed

- 2 patterns can occur in one nerve root

 

Supraclavicular Preganglionic / Root avulsion

 

Clinical

 

Severe pain in anaesthetised arm

- starts day 1 in 50%

- constant burning + superimposed `lightning shocks`down limb

 

Tender & swollen in posterior triangle

- pseudomeningocoeles

 

Tinel's negative

- dorsal root ganglion intact so no wallerian degeneration of sensory nerve

 

Horner's if T1

 

Evidence of injury to branches from roots

- long thoracic / serratus anterior

- dorsal scapular / rhomboids

 

Investigations

 

NCS

- SNAP normal (as fibres in continuity with DRG)

- abnormal sensation

 

EMG

- denervation dorsal neck muscles (posterior rami)

 

Diaphram paralysis

- high nerve root lesion / phrenic nerve

 

MRI Neck

- pseudomeningocoeles

- empty root sleeves

 

Patterns

 

1.  Erb's Palsy

 

C5 & 6 +/- 7

- also lose branches from roots and trunk

- long thoracic / dorsal scapular / suprascapular

 

Clinical

- shoulder adducted & internally rotated

- elbow extended

- forearm pronated 

- waiter's tip

 

Brachial Plexus Erbs

 

Paralysis of 

- deltoid / abductors

- SS / abductor

- IS / external rotator

- biceps / supinator and elbow flexor

 

Sensory loss

- lateral shoulder

- lateral forearm and hand

 

2.  Klumpke's palsy

 

C8 & T1 lesion

- paralysis intrinsics, wrist and finger flexors

- sensory changes medial hand and forearm

 

Klumpkes Hand 1Klumpkes Hand 2Klumpes Forearm

 

Horner's 

- ptosis (drooped)

- miosis (small)

- anhidrosis (dry)

- enophthalmos (sunken)

 

Supraclavicular Postganglionic (trunks)

 

Diagnosis

 

Tinel's positive

 

SSN / DSN / LTN intact

 

No Horners

 

Patterns

 

Erb's Palsy

 

Klumpke's Palsy

- no Horner's

 

Infraclavicular

 

Peripheral nerve patterns

 

A.  Lateral cord weak (C5,6,7)

 

MCN

- biceps (C5)

 

Lateral cord median

- FCR (C6)

- PT (C6)

 

Lateral pectoral nerve

- clavicular head

 

B.  Posterior cord weak (C5-T1)

 

AXN (C5)

- deltoid

 

Radial nerve

- triceps (C7)

- ECRL / ECRB (C8)

- EDC (C8)

- EPL (C8)

 

Upper and lower SCN (C5,6)

- SSC, T major

 

LTN (C5,6,7)

- latissimus dorsi

 

C. Medial cord weak

 

Ulna nerve (C7,8 T1)

- FCU (C8)

- LF FDP (C8)

- interossei (T1)

 

Medial median Nnerve

- FDP IF / MF

- FPL

- Thenar / APb

 

Medial pectoral

- sternocostal P. major

 

X-rays

 

CXR

- elevated diaphragm (phrenic nerve injury)

- fractured 1st rib

- suggests root avulsion

 

C spine Xray

- avulsion of C7 TP 

- suggests root avulsion

 

Shoulder Xray

- fracture clavicle / Scapula / GHJ / ACJ / SC

 

NCS / EMG

 

Takes 3 weeks for Wallerian degeneration / denervation to occur

 

EMG

- muscle sample of specific groups of interest

- denervation / sharp waves & fibrillation potentials

- re-innervation / polyphasic AP on volitional activity

 

Preganglionic lesion

 

NCS

- Skin Anaesthetic 

- SNAP persist because of DRG

 

EMG Denervation in

- paravertebral muscles

- serratus anterior

- rhomboids

 

Postganglionic lesion

 

NCS

- skin anaesthetic

- no SNAP as due to wallerian degeneration

 

MRI

 

MRI C Spine

 

Nerve root avulsion

- displacement or oedema spinal cord

- empty foramen

- pseudomeningocoeles (takes 5 days to develop)

 

MRI Shoulder

 

Difficult to correctly image trunks and cords

- high amount of oedema / hard to define severity of injury

 

Hems et al J Hand Surg Br 1999

- some usefulness in identifying level of injury in postganglionic

 

Prognosis 

 

1.  Infraclavicular > Supraclavicular

 

2.  Upper trunk > Lower trunk

 

3.  Better in children and young adults

 

 

 

Management

Goals

 

1.  Shoulder abduction and ER

2.  Elbow flexion

3.  Wrist extension

4.  Median nerve / C67 / lateral cord sensation

5.  Finger flexion

 

Options

 

1.  Nerve repair / neurorrhaphy

2.  Neurolysis

3.  Nerve graft

4.  Nerve transfer / neurotisation

5.  Tendon / muscle transfer

 

Open injury / laceration

 

Immediate surgery

- can tag ends and return later

- primary repair / nerve graft

 

GSW

- can continue to improve over time

- blast injury to plexus

 

Surgical Approaches

 

Supraclavicular

 

Z incision

- longitudinal along posterior border SCM

- transverse along inferior clavicle

- longitudinal in deltopectoral groove

 

Supraclavicular approach

- posterior triangle

- SCM / omo-hyoid / clavicle / trapezius

 

Superficial dissection

- subcutaneous Tissue

- platysma

- elevate clavicular head of SCM

 

Deep dissection

- may need to divide omo-hyoid

- identify scalenius anterior and medius

- ligate external jugular vein

- suprascapular and transverse cervical arteries

 

Uses

- identify nerve roots / nerve stimulation

- nerve graft C5, C6, C7

- phrenic or accessory to SSN

 

Infraclavicular

 

Deltopectoral approach

- P. major tendon divided

- P. minor reflected from coracoid (leave stump to repair)

 

Uses

- nerve stimulate medial pectoral nerve

- if working transfer to MCN

- or ICN / Oberlin

 

Pre ganglionic lesion / Nerve root avulsions

 

Options

- spinal cord level nerve root reimplantation

- nerve transfers

 

Spinal Cord Level Nerve Root Reimplanation

 

Results

 

Carlsted et al Neurosurgical Focus 2004

- reimplanation of nerve root avulsion in 9 year old boy

- C5 - T1

- regained motor function in arm and hand use

 

Carlsted et al J Neurosurg 2000

- nerve reimplantation in 10 patients

- surgery from 10 days to 9 months

- 3/10 recovered MRC grade 3 power

- better with higher lesions and earlier reimplantation

 

Shoulder Nerve Transfers

 

A.  Accessory nerve to SSN

 

Technique

- test trapezius

- surgery performed in the posterior triangle

 

Suzuki et al J Reconstruct Microsurg 2007

- accessory nerve to SSN in 12 patients

- average shoulder flexion 70o

- average shoulder abduction 77o

 

B.  Consider ICN to axillary nerve

 

Biceps Nerve Transfers

 

Connect to motor unit MCN

 

A.  Medial pectoral nerve to MCN

 

Issue

- much simpler than ICN

- often not intact

- test with nerve stimulator

 

B.   ICN to MCN

 

Issue

- problem is disparity in axon number

- T3-6 in males

- T3,4,7,9 in females to avoid breast denervation

 

Merrell et al J Hand Surg Am 2001

- 90% achieved MRC grade 3 power

- 70% grade 4 power

 

C.  Motor branch ulna nerve to MCN / Oberlin transfer

 

Technique

- use nerve stimulator

- isolate motor branch to FCU, preserving intrinsics

 

Sensation median nerve

 

ICN to lateral median

 

Hatori et al Plast Reconstr Surg 2009

- 17 patients

- none recovered 2 point discrimination

- 13 had perception of cold, 8 had perception of head

 

Post ganglionic lesion

 

Timing

 

A.  Late / 3 months

- evaluate recovery on EMG

- look for renervation potentials

 

B.  Immediate repair

 

Options

- neurolysis

- nerve repair

- nerve grafting

 

Neurolysis

 

Indication

- nerve functioning with nerve stimulator

- release nerve

 

Nerve repair 

 

Indication

- ruptured

- able to perform tensionless repair

 

Nerve graft

 

Indication

- non functioning on nerve stimulator

- long segment of clearly severely damaged nerve

- rupture unable to be repaired primarily

 

Graft Options

- sural nerve (30cm)

- saphenous

- MCNFA

 

Options

- C5 to SSN for shoulder abduction

- C5 to posterior division upper trunk (axillary)

- C6 to anterior division upper trunk for elbow flexion

- C7 to posterior division middle trunk (wrist and elbow extension)

 

Late salvage

 

Options

- shoulder fusion

- elbow flexion / tendon transfers

- wrist fusion

- amputation

 

Shoulder fusion

 

Need functioning serratus anterior and trapezius

- for scapula control

 

Elbow Flexion

 

1.  Lat Dorsi transfer

- entire muscle mobilised on NV pedicle

- attached proximally & distally to replace biceps

 

2.  Triceps to Biceps transfer

 

3.  Steindler flexorplasty

- transfer of CFO to more proximally on anterior humerus

- need power of wrist flexors

- will often get some pronation deformity

- also need wrist extensors to prevent excessive wrist flexion

 

4.  Clark Pectoralis major transfer

- transfer of sternocostal P. major

 

5. Free Gracilis transfer

- innervated by ICN

 

Wrist arthrodesis

 

Mid humeral amputation

 

Indications

- flail limb

- limb is a hazard

 

Shouldn't be performed for pain relief

 

 

 

Nerve Conduction Studies / EMG

Pathological Processes

 

Two possible types of injury

1.  Axonal

2.  Myelin sheath

 

Myelin Sheath Damage

 

Causes

 

Commonly seen in compression

- i.e. CTD, ulna nerve at elbow

- area of focal demyelination

 

Can progress to a conduction block

- some or all axons simply stop working

- decreases the amplitudes

 

Effect

 

1.  Usually affects sensory fibres first

- affects motor fibres later

 

2.  Results in slowing of conduction velocity

 

3.  Prolonged distal latency

- i.e. long time for stimulation to reach recording electrodes

 

4.  Effect is focal

- slowed conduction velocity above block

- normal below

- can isolate level of entrapment

 

5.  If progresses to conduction block

- decreased amplitude

 

Axonal Damage

 

Cause

 

Due to severe damage to the axon

- laceration / avulsion / severe contusion i.e. Sunderland type 3 and 4

 

Effect

 

1.  Decreased amplitude - related to number of axons affected

2.  Normal latency and conduction velocity

3.  In contrast to demyelination, cannot get normal result by stimulating below level of lesion

 

SNAP

 

Definition

 

Sensory nerve action potentials

 

Technique

 

Stimulate a sensory nerve and measure the action potential distally

 

Median nerve

- two stimulations over median nerve in forearm (S)

- ring type recording (R) electrodes on index and middle finger (sensory nerves only)

 

Ulna nerve

- stimulation over ulna nerve at elbow or wrist

- record over little finger

 

Measure

 

Latency

- time to reach distal electrodes

 

Conduction velocity

- simply measure distance between electrodes

- computer calculates velocity

 

Amplitude

- number of axons being stimulated

- also need all the axons transmitting at a similar velocity or get a wide, shorter velocity

 

NCS Sensory

 

Uses

 

Diagnosis of carpal tunnel syndrome

- measure conduction velocity

- in upper limb is usually > 50 m/s

- compare to ulna nerve / standard charts

- median nerve is slower than ulna, but difference should be < 0.2 ms

- usually use 0.3 ms as cut off

 

Ulna nerve compression

 

CPN compression

 

Radial nerve

 

Sciatic nerve

 

CMAP

 

Definition

 

Combined motor action potential

- called this because is difficult to stimulate just one muscle

- i.e. on thenar eminence want to stimulate just APB, but would get FPB also

 

Technique

 

Stimulate a nerve and record from a muscle that it innervates

 

Measure

 

1.  Distal latency

 

2.  Conduction velocity

- stimulate at 2 points and measure difference between times

- 50 m/s UL

- 40 m/s LL

 

3.  Amplitude

 

NCS Motor

 

Uses

 

Same as for SNAP

- entrapments

- slowing of conduction velocity and latency with demyelination

- +/- decreased amplitude if any axonal damage (severe entrapment, traumatic contusions, lacerations)

 

MNAP

 

Principle

Combine sensory and motor

- measuring electrodes simply in palm in median nerve distribution

- measure sensory and motor components

- see in delayed latency or conduction velocity

- very simple for CTD

- can move onto more specific SNAP and CMAP if needed

 

Responses

 

Amplitude

 

Proportional to number of functional axons

- loss of axons causes decrease in response amplitude

- amplitude is a measure of the total number of functioning axons in the nerve

 

Conduction Velocity

 

Calculated fro

m the latency values

- reflects only the function of the fastest conducting fibres

- fortunately most compressive or traumatic disorders affect the largest fibres

 

Calculated by

- dividing the latency by the distance between the stimulating and recording electrodes

 

Problem in CMAP

- the response is measured over the muscle

- the delay at the motor end plate must be considered

- conduction slowed by the small, unmyelinated terminal branches of the motor axon

- and by the time taken for release of Ach

- typically ~1 mS

- because the delay is fairly constant the terminal latency can be compared with the range of normal values

 

The Late Responses

 

Uses

 

Nerve root or proximal nerve lesions 

- cannot use simple NCS

- stimulate a peripheral nerve and recording over a muscle

- wait for a delayed signal

-  has travelled up the nerve to the anterior horn cell then returned to the muscle

 

F Response

 

Technique

 

Supramaximal stimulus is applied to a nerve

- motor nerves are directly depolarised

- like all axons they conduct equally well in all directions

 

2 impulses

Orthodromic 

- which travels to the muscle and produces the typical M response

 

Antidromic 

- which travels back to the anterior horn cell and depolarizes the cell body

- to be detected, the second muscle contraction has to occur after the first has subsided

- only muscles in which the round trip takes over 15 - 20 mS can be used

 

Problem

 

Does not measure sensory nerves

 

Uses

 

Brachial plexus injury

- want to know if nerve roots intact

- look in muscles relevant for each nerve root

- i.e. stimulate median nerve, look in thenar eminence (T1)

- look to see if F wave intact, delayed or absent

- problem is most muscles supplied by more than one nerve root

 

Now

- use MRI to see if nerve root avulsion

 

H Reflex

 

This is the electrical equivalent of the deep tendon reflex

A mixed peripheral nerve is sub maximally stimulated

- stimulates the large myelinated sensory nerves that convey muscle stretch

- they are the most easily depolarised of the axons

- following a relatively weak stimulus these sensory fibres are selectively depolarised

- a signal ascends to the dorsal root ganglion and then through the monosynaptic reflex arc

- depolarises the anterior horn cells 

- causes a secondary signal in the motor axons with a subsequent muscle contraction

 

Characterised by having a consistent latency 

- is elicited by a stimulus so small that it does not cause a direct muscle contraction.

 

Unfortunately it can only be elicited in the tibial nerve (and recorded over the gastrocnemius)

 

Electromyography (EMG)

 

Technique

 

Needle placed in relevant muscle

- record electrical potential

- at rest and voluntary contraction

 

NCS Motor

 

NCS Waveform

 

Neuropathy

 

Denervation

- takes 3/52 to see

- amount of time for wallerian degeneration to occur

- if do earlier will get a false negative

- normal muscle electrically silent at rest

 

Findings

- spontaneous depolarisation in muscle

- fibrillations

- positive sharp waves

 

Reinnervation

- takes 3/12 to see

- due to surviving motor axons branching out and recruiting other motor units

 

Findings

- see large polyphasic motor unit potentials

 

Myopathy

 

Muscle problems

- specific patterns of EMG
- Duchenne's muscular dystrophy /myotonica dystrophy

 

Shortfalls of EMG

 

It is only a sampling technique

- normal areas in an abnormal muscle may have normal potentials

 

Specific uses of NCS / EMG

 

Conduction blocks

 

SNAP / CMAP

- median nerve, ulna nerve

- confirm entrapment

- evaluate site of entrapment

 

Axonal / Nerve damage

 

1.  Radial nerve palsy with humeral fractures 

 

Question

- is nerve in continuum or lacerated?

 

NCS / EMG cannot tell you that

- similar findings for Stage 4 and 5 Sunderland

 

Can give information regarding severity of injury

- denervation potentials at 3/52

- indicates Sunderland grade 3 or greater

 

Can give idea of prognosis

- i.e. is there any chance of recovery?

- reinnervation on EMG at 3/12

 

2.  CPN injury at knee, sciatic nerve injury following THR

 

Can give you idea of prognosis

- i.e. SNAP intact at 3/12

- neuropraxia

 

Neuropraxia

 

Minimal axonal damage

- demyelinating / conduction block only

- no Wallerian degeneration

 

Findings

 

3/52

- some SNAP and CMAP still seen

- minimal denervation signs i.e. fibrillation

- means nerve is not too badly injured

- prognosis good

- should be just a neuropraxia

 

Laceration / Neurotmesis

 

Both conditions will lead to Wallerian degeneration

- severity dependant on number of axons injured

 

3/52

- no SNAP / CMAP

- may be reduced or no amplitudes depending on number of axons injured

- see fibrillations in muscle in EMG due to denervation

 

3/12

- looking for reinnervation

- hoping to see large polyphasic AP due to surviving motor axons branching out and recruiting

- if this is not seen, is a poor sign as means no surviving axons

- can repeat later hoping some axons have sprouted down intact tube

 

Problems with NCS

 

1.  Obese patient

2.  Oedema

3.  Electrical inteference

- 50 MHz from fluorescent lights

- need to do in Faraday room

- difficult to do in ICU

4.  Must remove oils / moisturiser

5.  Sweat

 

Spinal Cord Monitoring

 

Used to assess spinal cord integrity during spinal instrumentation

 

Technique

 

Posterior tibial nerve stimulated

- scalp SEP used to monitor for surgical induced changes

- signal monitored is in the posterior column

- relatively immune to compromise of the anterior spinal artery

- motor control is located anteriorly in the descending corticospinal tracts

 

 

Nerve Entrapment

Median Nerve

Anatomy Median Nerve

 

Formation

- medial and lateral branches median nerve

- from medial and lateral cords respectively

- C5 - T1

- median branch crosses artery, such that median nerve lies lateral to artery

- no branches in arm

- medial nerve crosses brachial artery to lie medial to it

 

Elbow

- nerve medial to artery at elbow

- passes under bicipital aponeurosis then between heads of pronator teres

(sublime tubercle and CFO)

- medial nerve supplies PT, FCR, PL, FDS 

 

AIN 

- arises as pass between two heads PT from the dorsal aspect of median nerve

- occasionally passes deep to deep head of PT

- passes beneath arch of FDS

- runs distally along intra-oseous membrane between FDP & FPL

- branch to FDP / FPL ~ 4 cm distal to origin then branch to PQ

 

Median nerve 

- runs under arch of FDS to run on FDP

- crosses the ulna artery  

- at wrist it is lateral to FDS tendons, medial to FCR with PL above

- palmar cutaneous branch emerges on radial side of PL to run over TCL

 

Branches

 

1.  Motor recurrent 

- usually arises laterally

- sometimes comes off medial side and runs over distal edge of TCL (danger during endoscopic CTD)

- can pass through TCL

 

2.  Medial sensory branch

- gives two common digital nerves

- motor to first 2 lumbricals

 

3.  Lateral branch 

- supplies thumb and lateral index finger

 

 

 

Anterior Interosseous Nerve Palsy

Definition

 

Symptoms & signs due to compression of AIN

 

Sites of Compression

 

Fibrous

- Pronator Teres (most common)

- FDS arch

- Fascial bands 

- Bursa

 

Vascular

- thrombosis in leash vessels over AIN

 

Muscular

- aberrant belly FPL (Gantzer's)

- palmaris profundus

- aberrant FCR ulnar origin

- anomalous FDS origins

 

History

 

1.  Pain in proximal forearm

- vague pain

- most common symptom

 

2.  Motor deficiency

- FPL

- IF FDP

- PQ

 

3.  No sensory disturbance

 

Examination

 

Discomfort over site of compression

 

Inability to tip-to-tip pinch grip IF &Thumb

- weak pulp-to-pulp pinch possible

- Weak FPL / Index FDP / PQ

 

Provocation

- resisted pronation with elbow flexed 90o

 

Investigation

 

EMG FDP / FPL / PQ

 

DDx

 

Rupture FPL / FDP

Median N entrapment

C8 lesion

 

Management

 

Non operative Management

 

Avoid Aggravating Factors

RICE

NSAIDS

 

Operative Management

 

Technique

 

Release

- as per pronator syndrome

 

Results

 

Schantz et al J Hand Surg Br 1992

- 20 cases of AIN compression

- operated on 15 with 12 good results / 3 required tendon transfer

- non operative on 5 / 3 continued palsy at 4 years

- recommended operative release

 

 

Carpal Tunnel Syndrome

Definition

 

Symptoms & signs due to compression of median nerve in carpal tunnel

 

Epidemiology

 

Middle aged female

- F:M   2:1

- peak age 40-50 years

- often bilateral

 

Aetiology

 

Underlying process is decreased microvascular perfusion 

- normal press in CT is 2.5mmHg

- most CTS > 30 mmHg & > 90 mmHg with palmar flexion

 

Commonest cause in tenosynovitis

 

Anatomical

 

1. Decreased size

- bony abnormality / thickened TCL

 

2. Increased contents

- hypertrophic synovium / fracture callus / hematoma

- neuroma / lipoma

- abnormal muscle bellies / persistent median artery

 

Physiological

 

1. Neuropathic Conditions

- diabetes / alcoholism / proximal lesion of median nerve (Double Crush)

 

2. Inflammatory Conditions

- tenosynovitis / RA / infection / gout

 

3.  Altered fluid balance

- pregnancy / eclampsia / OCP

- thyroid problems / CRF / acromegaly / obesity

 

Patterns of Use

 

1.  Repetitive flexion / extension

- manual labour / typing

 

2.  Weight bearing with wrist extended

- paraplegia (weight bear on palms) / long-distance cycling

 

3.  Vibration

 

Anatomy

 

Transverse carpal ligament / TCL

- tuberosities of scaphoid and trapezium laterally

- pisiform and hook of hamate medially

- distal volar wrist crease proximal limit

- Kaplan's line (apex of interdigital fold between thumb and IF) distal limit

 

Carpal tunnel

- FCR in separate tunnel with FPL separate and below

- median nerve radial to 4 FDS

- IF / LF below MF / RF

- 4 FDP at base

- FPL separate 

 

MRI Wrist Carpal TunnelMRI Wrist Carpal Tunnel 2

 

Motor Branch of Median nerve

 

Most important structure at risk / location can vary

 

1. Extraligamentous Recurrent / 50%

- branches distal to TCL with recurrent course to thenar muscles

 

2. Subligamentous / 30%

- branches beneath TCL / lies close to median nerve

- recurrent course to thenar muscles distal to TCL

 

3. Transligamentous/ 20%

- branches beneath TCL and pierces TCL to enter thenar muscles

 

4. Other

- proximal division

- branch from ulnar border of median nerve

- nerve superficial to TCL

 

Palmar Cutaneous Branch of Median Nerve

- arises in distal 1/3 of forearm from palmar-radial side of median nerve

- usually 5 cm proximal to wrist

- Pierces deep fascia between FCR & PL

 

History

 

Often diverse 

 

Classic

- pain & numbness radial 3± digits

- nocturnal wakening with relief from shaking

- worse with driving

 

Examination

 

Look

- thenar wasting

 

Feel

- abnormal thenar sensation suggests higher compression

- decreased sensation lateral 3 1/2 digits

 

Move

- APB weakness

 

Augmented Phalen's 

- elbow extended & supinated

- wrist held flexed 60° 2 fingers for 30 seconds

- sensitive 80% / specific 99%

 

Tinel's

- percussion of the median nerve at wrist 

- paresthesia in distribution of median nerve indicate a positive test   

- sensitive 75% / specific 95%

 

DDx

 

EJ compression

- more proximal pain / AIN weakness

 

T1 lesion

- check interossei power

 

C6/7 lesion 

- similar sensory loss

- check wrist extension / triceps

 

NCS

 

SNAP

 

Stimulate proximally

- measure in IF and MF (sensory only from median)

- measure latency / conduction velocity / amplitude

 

Conduction velocity

- compare to ulna nerve

- usually > 50 m/s

- median nerve slightly slower

- should be within 0.2 / 0.3 m/s

- can compare to tables or to contralateral median nerve (may be bilateral pathology)

 

Latency

- > 3.5 ms = Abnormal

- > 1 ms between sides

 

Results

 

90% sensitive

 

10% false negative rate

- intact conduction in a small number of fibres will give normal conduction velocity for whole nerve

- normal study does not rule out CTS

 

EMG

 

Denervation activity (late change)

- spontaneous depolarisation

- fibrillations

 

Re-innervation

- large polyphasic AP

 

X-ray

 

Exclude wrist arthritis / tumour

 

Management

 

Non-operative management

 

Options

 

Splint

 

Wrist in neutral / Night splints

 

NSAID

 

HCLA

 

Risk

- must avoid intraneural injection

- can cause chronic pain and disability

 

Pregnancy

 

Incidence

- 2%

- most recover 6/52 after delivery

- very rarely require decompression

 

Management

- splints

- HCLA

 

Operative Management

 

Indications

 

Failure non operative management

Permanent numbness / weakness

- indicates nerve damage which may not resolve

 

Options

 

Open carpal tunnel release

Endoscopic carpal tunnel release

Neurolysis

 

Open Carpal Tunnel Release 

 

Effect

 

1.  Increase volume carpal tunnel by 25% 

 

2.  Increases Guyon's canal

- may relieve compression ulna nerve / LF numbness

- Guyon's canal goes from triangular to circular

 

Technique

 

LA infiltration over site of release

- incision in line with radial side ring finger

- parallel to and ulna side of thenar crease

- if cross wrist, ulna side of PL to avoid palmar branch of median nerve

- divide palmar aponeurosis which has longitudinal fibres

- divide TCL which has transverse fibres

- ensure released proximally and distally

- inspect for ganglion etc

 

Endoscopic CTR

 

Issues

- transection of recurrent branch median nerve

- especially with abnormal anatomy and inexperienced surgeons

 

Technique

 

GA, Tourniquet

 

Proximal transverse incision at wrist crease

- insert spatula

- under TCL, feel it, clear soft tissue

- insert cannula

- exits in palm through distal incision

- wrist DF over bump with strap

 

Insert camera looking up at TCL

- must see transverse fibres in full for entire length

- clean with Q tip, or with probe if needed

- ensure nerve branches not crossing plane

- cut with hook knife under vision

 

Results

 

Trumble et al JBJS Am 2002

- RCT of 192 patients open v endoscopic

- better grip strength in first 3 months

- less scar tenderness and earlier return to work

- no complications from endoscopic technique

 

Complications

 

Incorrect diagnosis

 

Incomplete decompression

 

Division of palmar branch

 

Palm dysaesthesia with is difficult to salvage

- sensitivity often precludes use of hand

- avoid by always staying ulnar to thenar crease

 

Diagnosis

- confirmed by LA block

 

Management

- explore and bury nerve ending

 

Hypersensitive Scar

- much more common if cross wrist crease

 

"Pillar Pain" 

- 4% at 10 months post surgery

 

RSD

- decreased with minimal nerve trauma & avoiding neurolysis

 

Division of recurrent branch 

 

Management

- operative repair

 

Tenderness / sensitivity of median nerve

 

Cause

- due to superficial course post op

 

Management

- if a real problem needs soft tissue to cover

- proximally can use pronator quadratus

- distally use hypothenar fat graft on vascular pedicle

 

Flexor tendon bowstringing or adhesions

- Bowstring tendons 2% of open CTR

 

Persistant numbness

- may take 12 months for all symptoms to resolve

- loss of Schwann cells resulting in persistent conduction block

 

Recurrence

 

History

- symptom free interval

- usually due to scar

 

 

 

Pronator Syndrome

Definition

 

Forearm pain caused by compression of median nerve

 

Sites of Compression

 

Pronator Teres

- commonest site

- hypertrophied / excess fascia

 

Ligament of Struthers

- remnant third head Coracobrachialis

- runs from supracondylar spur to medial epicondyle

- median nerve & brachial artery may be deep to it

 

Bicipital Aponeurosis

- lacertus Fibrosis

- from medial border of biceps to subcutaneous ulna border

- may be thickened

 

Arch of FDS

- runs from humeroulnar Head (origin CFO & Sublime tubercle medial coronoid) 

- inserts anterior oblique line on radius

- accessory muscle slips and anomalous origins of FDS

 

History

 

Pain in anteromedial EJ / volar aspect of distal arm 

- worse with repetitive pronation / supination eg tennis, tools

 

May have

- intermittent / nocturnal parasthesia

- some weakness

 

Examination

 

Tenderness at site of compression

- proximal flexors

 

Pain with resisted pronation elbow in flexion / PT

 

Other provocations test

- Ligament of Struthers - resisted flexion of elbow at 135°

- Bicipital aponeurosis - resisted supination flexed elbow 

- Arch of FDS - resisted flexion of FDS of MF

 

NCS

 

Aim

- confirm location 

- exclude CTS

 

Findings

- delayed conduction velocity across elbow 30%

- EMG abnormalities of PT or FCR

 

X-ray

 

Spur

- seen with ligament of struthers

 

MRI

 

May help identify site of compression / ligament of struthers

 

Management

 

Non-operative Management

 

NSAIDS

Avoid aggravating activities

RICE

 

Operative Management

 

Technique

 

Medial incision

- divide bicipital aponeurosis

- release pronator teres

- release FDS

- +/- ligament of struthers if present

 

 

 

 

Radial Nerve

Pin Syndrome

Definition

 

Loss of PIN motor function with no pain

- multiple potential causes

- may be caused by compression as per radial tunnel

- may be post fracture or surgery

- may be caused by synovits / ganglion / rheumatoid nodules etc

 

Symptoms

 

Often heralded by deep aching pain in forearm that resolves

- is followed by PIN weakness

 

Most commonly is incomplete lesion

- weakness of extension of index and middle or just thumb

 

Examination

 

No sensory loss

 

Characteristic radial deviation with wrist extension

- BR & ECRL functioning

- supplied by radial nerve

 

NCS / EMG

 

Can be helpful

 

EMG of appropriate muscles

- demonstrates denervation

 

MRI

 

Looking for mass lesion

 

Site of Compression 

 

FREAS

 

Trauma - Monteggia fracture

Iatrogenic - surgery radial head / radius

Inflammation - RA nodule / synovitis of radio-capitellar joint DRUJ

Masses - lipoma / ganglia

 

Local injections

Lead poisoning - usually bilateral / motor palsy without sensory

Conversion reaction

Polyarteritis Nodosa

Muscle rupture

 

DDx

 

Locked trigger finger

Tendon rupture

 

Management

 

Non operative

 

Splint / therapy

- wait 3 months for recovery

 

Operative

 

Indications

- ganglion / rheumatoid nodule / synovitis

- failure to recover post operatively

 

Technique

 

Operative release

- posterior approach

- between EDC and ECRB

- divide supinator

 

PIN in radial tunnel release

 

 

Radial Nerve Anatomy

Originates

- terminal branch posterior cord / C5 - T1

- runs anterior to subscapularis / teres major / lat dorsi

- passes into triangular space (between humerus / long head of triceps / teres major)

- enters posterior compartment of arm

 

Arm

- runs in the radial groove between medial and lateral head of triceps, with profunda brachii

- gives a branch to the long and medial head of triceps (this branch runs with the ulna nerve) before the groove

- also gives the posterior cutaneous nerve of the arm

- in the groove branches to the lateral head  again to the medial head (this branch also supplies anconeus)

- also the lower lateral cutaneous nerve of the arm and the posterior cutaneous nerve of the forearm, which perforates the lateral head

 

Elbow

- passes anteriorly through intermuscular septum

- runs between BR / ECRL laterally and brachialis medially

- supplies these muscles and the elbow joint

- at the level of the lateral epicondyle, the radial nerve divides into superficial branch radial and PIN

 

Superficial branch

- runs under BR until it emerges between it and FCR

- runs superfical to first extensor compartment

- supplies dorsum of hand

 

Supinator

- has superficial and deep layers

- originates from the supinator crest of the ulna

- inserts onto the lateral surface of the radius between the anterior and posterior oblique lines

 

PIN

- passes through the radial tunnel which is between the radiohumeral joint and the distal extent of supinator

- passes under a fibrous band of ECRB

- under the radial recurrent leash of vessels

- into supinator (arcade of Frohse)

- then out from under another fibrous band of supinator

- runs over APL

- dips to run on the interosseous membrane

- ending as a small nodule which supplies the wrist joint

 

PIN then divides

- a superficial branch (supplies EDC, EDM, ECU)

- the deep branch supplies APL, EPB, EI and EPL

 

 

 

 

Radial Tunnel Syndrome

Definition

 

Dynamic structural compression syndrome of PIN

- causing pain with little or no muscular weakness

- similar presentation to lateral epicondylitis / pain more distal

 

Anatomy

 

Radial tunnel begins at radiohumeral joint

Extends to end of supinator muscle

 

Sites of compression

 

PIN can be compressed by FREAS in radial tunnel

 

Fibrous bands

- level of radio-capitellar joint

 

Recurrent leash of Henry 

- radial recurrent artery

- vessels to mobile wad

 

ECRB 

- nerve branches caught between ECRB and supinator

 

Arcade of Frohse 

- free fibrous proximal edge supinator (superficial belly)

- most common site of compression

- thought to be more tendinous in some patients (30 - 80%)

- thought to become more fibrous in some patients with repetitive supination

 

Supinator distal edge

- occasional cause

- always decompress to here

 

Clinical

 

Pain is similar to tennis elbow

- lateral elbow joint / CEO area often radiating to wrist

- deep ache or similar to muscle cramp

- often at night

- exacerbated by exercise 

- relieved by rest

 

Examination

 

Point tenderness 5cm distal to CEO 

- more proximal with Tennis Elbow

- Often tender in normal individual --> compare to other side

 

Provocation test

- Arcade of Frohse 

- resisted supination

 

NCS 

- unhelpful / usually normal

 

Local Anaesthetic block

 

Best test

- inject LA in most tender spot

- usually distal to CEO

- must produce PIN palsy to confirm diagnosis

- A prior negative injection to lateral condyle for tennis elbow

 

DDx

 

Tennis Elbow

- failure of HCLA lateral epicondyle to relieve pain

- can have both tennis elbow and radial tunnel syndrome

 

Radiocapitellar pathology

- OA / RA / OCD / Loose body

- no pain with supination / pronation

 

Radiculopathy 

 

NHx 

 

Tends to resolve spontaneously

 

Management

 

Non-Operative

 

RICE

Avoid provocative activities

Splint

 

Operative

 

Options

- anterior (can release all potential sites of compression)

- posterior (can only release supinator)

- brachioradialis muscle splitting

 

Anterior approach

 

Henry's approach

- start 4cm proximal to elbow joint

- identify nerve between BR & Brachialis & then follow distally

- release any proximal fibrous bands / divide recurrent vessels

- pronate / supinate and release ECRB if any compression

- fully pronate and divide all fibres of supinator

 

Posterolateral approach

 

Thompson's

- incision just distal to lateral condyle for 8cm

- dissection between ECRB & EDC

- identify supinator

- find PIN distally and follow proximally

 

Trans-brachial approach

 

Brachioradialis splitting

- direct approach to radial tunnel

- longitudinal incision 6cm long over BR at neck of radius

- incise BR in line of incision

- identify fat covering superficial Radial Nerve

- beneath this branch is arcade of Frohse and PIN

- extend proximally and distally till released

 

Results

 

Jebson et al J Hand Surg Am 1997

- surgical release in 31 patients

- excellent or good results in 67%, fair or poor in 33%

 

Lee et al J Plast Recons Aesthet Surg 2008

- 86% good results in isolated radial tunnel syndrome

- dropped to around 50% if

- other nerve compression / lateral epicondylitis / workers compensation

 

 

 

 

 

 

Wartenberg's Syndrome

Definition

 

Compression of superficial branch radial nerve by ECRB / BR

 

Symptoms

 

Parasthesia first dorsal webspace

 

Associations

 

Up to 50% of patients also Dequervain's

 

Management

 

Non operative

 

Splint

HCLA

 

Operative

 

Surgical release / neurolysis

 

 

 

Ulna Nerve

Anatomy Ulna Nerve

Nerve supply

- C7, C8, T1 

- nerve picks up some branches of C7 from the lateral cord

 

Origin

- direct continuation medial cord

- runs between the brachial artery and the vein in the arm

- behind MCNFA

 

Arm

- pierces the medial intermuscular septum to run in posterior compartment

- runs anterior to the triceps

 

Elbow

- enters the cubital tunnel between the medial epicondyle and the olecranon

- running on MCL 

- covered by osbourne's ligament

- gives articular branches to the elbow

 

Ulna Nerve MRI Cubital Tunnel

 

Forearm

- runs between the two heads of FCU (anterior aspect medial epicondyle and proximal ulna)

- branches to (usually) medial 2 FDP and to FCU

- nerve descends on FDP, under the cover of FCU

 

Wrist

- nerve runs with the ulna artery to the wrist

- it emerges on the lateral aspect of FCU

- nerve is ulna to artery

- dorsal sensory branch which runs under FCU and supplies dorsum of hand in region of 1 and 1/2 fingers

- palmar cutaneous branch which supplies sensation over the hypothenar muscles

 

Guyon's canal 

- superficial to TCL

- under volar carpal / pisohamate ligament

- between hook of hamate and pisiform

- nerve is ulna to the artery

- at the distal edge volar carpal ligament divides into a sensory and motor branch

 

Motor branch 

- runs between abductor and flexor digiti minimi 

- through opponens 

- crosses the palm within the concavity of the deep palmar arch

- gives branches to the lateral 2 lumbricals, all the interossei and ends by supplying adductor pollicis

 

 

 

 

Cubital Tunnel Syndrome

Definition 

 

Symptoms & signs from compression of ulnar nerve near elbow

 

Sites of Compression

 

Proximal

 

Arcade of Struthers 

- thick myofascial band, 1.5-2cm wide

- present in 70%

- 8cm proximal to medial epicondyle

- from medial head of triceps to medial intermuscular septum, superficial to nerve

 

Medial intermuscular septum

- with subluxation, nerve may impinge on it 

 

Medial head of triceps

- hypertrophied (body builders)

 

Medial epicondyle

 

Tardy ulna nerve palsy / cubitus valgus

- compression due to valgus deformity of the bone

- previous supracondylar / lateral condyle fracture

 

Cubital tunnel / Osbourne's ligament

 

Anatomy

- walls are humeral & ulna heads of FCU

- floor is MCL

- roof is Osbourne's fascia (continuation of fibro-aponurotic covering of epicondylar groove)

 

Nerve compression 

- occurs in flexion as Osbourne's fascia tightens

- MCL bulges out and tunnel becomes flattened ellipse

 

FCU

 

Nerve passes intramuscular for ~5cm

- penetrates fascial layer to lie on FDP

- proximal and distal compression possible

 

Other

 

A. Lesions in the groove

- medial epicondyle fracture / arthritic spurs / HO

- lipomas / ganglia / osteochondromas / synovitis / rheumatoid nodule

- infection (TB, leprosy) /bleeding (haemophilia)

 

B. Conditions outside the groove

- external compression

- anomalous anconeus muscle

 

C. Subluxation / Dislocation from the groove

- laxity / traumatic tear of fibro-aponurotic roof

 

History

 

Pain on ulnar side of elbow

Pain & numbness in ulnar fingers

Provoked by elbow flexion

Weakness of fine movements

 

Examination

 

Look

- deformity or carrying angle

- full ROM

- wasting intrinsics dorsum hand

 

Wasting Adductor Pollicis Right Hand

 

Feel

- tenderness tunnel

- Tinel's

- subluxation ulna nerve

- sensation in hand / involvement of dorsal and palmar branches

 

Move

 

A.  Power FCU / FDP LF

 

B.  Hand

- intrinsics

- abductor digiti minimi

- adductor pollicis / 1st dorsal interossei (Froment's)

 

Froment's sign

 

Concealed

- C spine

- axilla

 

DDx

 

TOS

- symptoms worse with overhead position

 

C spine

- neck / shoulder pain

 

T1 nerve root lesion

- thenar muscle power will be reduced

- decreased sensation medial forearm

 

C8 nerve root lesion

- IF / MF FDP & FPL weakened

 

Ulna tunnel syndrome

- sensation normal palmar / dorsal branch

- FCU / FDP LF normal

 

Pancoast tumour

 

Systemic illness

- DM

- alcohol

- hypothyroid

- vitamin deficiency

 

NCS

 

High false negative

 

Test with elbow flexed

- < 50 m/s conduction velocity across elbow

 

EMG

 

Denervation in hypothenar muscles in severe cases

 

Management

 

Non-operative Management

 

Options

 

50% resolve with night elbow extension splint

Avoid leaning on elbows

NSAID

Rest / activity modification

 

Operative Management

 

Indications

 

Intrinsic weakness

Failed non-operative > 3/12

 

Options

 

1.  Open release

2.  Endoscopic release

3.  Open release + Nerve transposition

4.  Open release + Medial Epicondylectomy

 

1.  Open release

 

Indications

- mild disease

- normal anatomy

- no subluxation

 

Technique

 

Incision

- 10cm curved incision centred over cubital tunnel

- 1/2 way between olecranon & medial epicondyle

- extended proximally along medial edge of triceps & distally parallel to border of Ulna

 

Danger

- Posterior branch of MCNFA

 

Superficial dissection

- deepened through deep fascia

- nerve identified in proximal tunnel

 

Release

- proximally ensure no arcade of Struthers

- release Osbourne ligament

- distally release fibrous band of FCU

- ensure ulna nerve stable at end of case

- if unstable, transpose

 

Dangers

- protect distal muscular branches

- 2 branches to FCU 

- branch to FDP

 

Ulna Nerve ReleaseUlna nerve release test stability

 

Results

 

Ziowodzki et al JBJS Am 2007

- meta-analysis of decompression v anterior transposition

- no deformity or previous surgyer

- no evidence of improved outcome with anterior transposition

 

Vogel et al Br J Plastic Surg 2004

- revision surgery in 22 patients

- combination of simple release and subcutaneous transposition initially

- findings were scarring / incomplete release medial intermuscular septum / incomplete FCU release

- all had submuscular transposition and Z lengthening of CFO

- 78% satisfaction rate

 

2.  Endoscopic Release

 

Indication

- normal anatomy / simple release

- no SOL / ganglion requiring removal

 

Technique

 

Small incision over epicondylar groove

- release osbourne's ligament under vision

- lift skin flaps with special retractor proximally and distally

- insert 30scope

- release remainder ulna nerve under endoscopic vision

 

Results

 

Watts et al J Hand Surg 2009

- compared results from open and endoscopic release

- greater patient satisfaction in endoscopic with fewer complications

 

3. Nerve Transposition

 

Indication

- subluxation

- valgus deformity / FFD

- failed decompression / revision surgery

 

Advantage

- allows functional lengthening of nerve 3-4cm

- low recurrence rate

 

Disadvantage

- scar formation with possible new proximal site of compression

 

3 options

 

A.  Submuscular

- muscles elevated from CFO protecting MCL 

- nerve transposed anteriorly

- muscles reattached

 

B.  Intra-muscular

- 5 mm trough made in CFO 

- nerve transposed into groove

- superficial fascia closed over nerve

 

C.  Subcutaneous

- nerve transposed anterior medial epicondyle

- sutcutaneous tissue from skin flap sutured to muscle fascia behind nerve

 

4. Medial Epicondylectomy

 

Indications

- valgus deformity

- malunited fracture

- bony abnormality

 

Disadvantages

- produces scarring

- protection of medial epicondyle lost / pain if lean on elbows

- weakens flexors (contraindicated in athlete)

- MCL injury can occur

 

Technique

- nerve identified, released & protected

- CFO elevated

- medial condyle & supracondylar ridge removed

- guide is medial border of trochlea

- flexor origin attached to periosteum

- MCL should be left attached as it is deep & lateral

 

Complications

 

Hypertrophic scar

Neuroma MCNF

RSD

Non resolution of parasthesia

Ulna Tunnel Syndrome

Definition 

 

Symptoms & signs from compression of ulnar nerve in guyon's canal

 

May be purely sensory, purely motor or combination

 

Anatomy Guyon's Canal

 

4cm long ulnar tunnel

 

Floor - transverse carpal ligament

 

Roof - volar carpal ligament and pisohamate ligament

 

Walls - pisiform (ulna) & hook of hamate (radial)

 

Contents 

 

Ulna nerve and artery

- nerve ulnar to artery

 

Within canal at distal margin ulna nerve divides into 2

- superficial sensory

- deep motor branch

- separated by common tendinous origin of hypothenar muscles

 

3 zones

 

1.  Proximal to bifurcation ulnar nerve - motor and sensory branches

2.  Medial & distal to bifurcation - motor branch

3.  Lateral & distal to bifurcation - sensory branch

 

Aetiology

 

Intrinsic 

 

Soft tissue masses (including ganglia) 46%

Anomalous Muscles 16%

 

Extrinsic

 

Repeated blunt trauma 

 

Can also get

- thrombosis of ulnar artery / hypothenar hammer syndrome

- fracture of hamate (Golfer)

- aneurysm ulnar artery

 

History

 

Pain & paraesthesia in ulnar hand & fingers

 

Weakness hand

- difficulty fine motor skills

 

Examination

 

Look 

- hypothenar wasting / intrinsic wasting / ulna claw hand

 

Feel

- decreased sensation in LF

- decreased sensation hypothenar eminence / dorsal branch suggest higher lesion

 

Motor

- intrinsic weakness / abd digiti minimi / adductor pollicis / 1st dorsal interossei

 

Special

- Tinel's over Guyon

- Allen's test 

 

Cervical spine

 

DDx

 

Cubital Tunnel Syndrome

TOS

Cervical root compression

 

NCS / EMG

 

Confirm Guyon's canal site of compression

 

X-ray

 

Tunnel view

- hamate fracture / pisiform OA

 

MRI

 

Ganglion

 

Management

 

Non-operative Management

 

Restrict exacerbating activities

Splint in neutral

NSAIDs

 

Operative

 

Release

 

Incision

- radial border of FCU 

- 3 cm proximal to wrist crease 

- across crease and along line of ring finger 

 

Superficial dissection

- ulnar nerve isolated proximal to  wrist 

- followed into Guyon's canal 

 

Deep dissection

- divide volar carpal ligament

- divide pisohamate ligament

- resect hook hamate or pisiform if needed 

 

Dangers

- injury palmar branch ulna nerve

 

 

 

 

Peripheral Nerve Injury

Anatomy of the peripheral nerve 

 

Endoneurium 

- loose collagenous matrix

- surrounds the individual nerve fibers within the fascicle

 

Perineurium 

- thin, dense connective tissue sheath that surrounds each fascicle

 

Epineurium 

- a loose meshwork of collagen  and elastin fibers 

- provides a supportive and protective framework for the fascicles

- collagen fibers in the epineurium are thicker than those in the endoneurium / perineurium

 

Definition

 

Neuropraxia

- focal demyelination 2° ischaemia

- full recovery by 3 months

 

Axonotmesis

- axon disrupted

 

Neurotmesis

- nerve division

 

Seddon & Sunderland  Grading

 

1st Degree / Neuropraxia

- localised conduction block leading to segmental demyelination

- axons are not injured

- remyelination and recovery < 3 months, no Tinel's

 

2nd Degree / Axonotemesis

- axonal injury with distal segment Wallerian degeneration

- full recovery

- nerve fibres regenerate 1 mm per day

- but > 3 months, advancing Tinel's

 

3rd Degree / Endoneurium disrupted

- incomplete recovery due to fibrosis

- advancing Tinel's

 

4th Degree / Perineurium divided / Epineurium intact

 

Nerve is in continuity but complete block due to scar

 

Poor prognosis

- perineurium disrupted

- becomes filled with scar

- no recovery, no Tinel's

- no SNAP, denervation potential

- no rennervation at 3/12 (polyphasic AP)

 

Often needs repair 

 

5th Degree / Epineurium divided

- 100% divided / neurotmesis

 

6th Deg (added by Susan McKinnon)

- neuroma in continuity

- mixed recovery

 

Injury Response 

 

Wallerian Degeneration

 

Axon dies distally

- remains intact for 3/24 (until stores depleted)

 

Schwann cell proliferation and macrophage ingrowth

- clear distal stump of axoplasm & myelin

- prepares way for new axon 

 

Axon Regeneration

 

Axon sprouts enter distal endoneural tubes

- 1-2 mm/day

- survive if contact an end organ

- sprouts often enter wrong tube & wrong end organs

- some axons fail to cross repair site & form neuroma

 

Axon Guidance 

 

1. Directional Neurotropic Cues 

- target releases tropic factor

 

2. Survival Neurotropic Cues 

- tube supports correct axon

 

3. Mechanical Alignment 

- worst

 

4. Contact Recognition 

- path selection based on surface

 

Sensory Fibres

 

Survive years of degeneration

- sensory return order

- pinprick / moving touch / constant touch / vibration

 

Muscle Fibres

 

Myofibrils atrophy without nerve

- 50% in 2/12

- fibrotic by 12/12

- need to repair < 9/12

 

Neuromuscular Junction

 

Receptor dispersal over 12 months

- needs to be re-innervated prior to 12 months

 

Receptor becomes more sensitive to ACh

- spontaneous fibrillation start Day 10 

- significant EMG changes > 2/52 

 

Neuronal Response

 

Cell body dies if very proximal axon injury

- 2° ion leakage

- if neurone survives body & nucleolus enlarges

- regenerative proteins produced

- responsible for delay in nerve recovery / regeneration

 

Mechanism Injury

 

1. Open wounds

 

2. Compression

- pressures > 30 mmHg impair venular epineural flow

- retards axonal transport

- alteration in intraneural BV permeability

- leads to nerve function deterioration 

- relative to length of compression & absolute pressure 

 

Tourniquet

- UL 200 mmHg / Max 90 min

- LL 300 mmHg/ Max 120 min

 

3. Traction

 

4.  Thermal 

 

5.  Irradiation Neuritis

 

6.  Injection

 

Recovery Assessment

 

EMG

 

Denervation

- 3 weeks

- fibrillation potentials

- positive sharp waves 

- spontaneous AP

 

Reinnervation

- polyphasic AP  

 

Tinel's Sign

 

Percuss along the nerve

- transient tingling in nerve distribution not at injury site

- indicates axonal sprouts progressing along tube that haven't remyelinised

- response fades proximally secondary to progressive myelinization

 

Sweat Test

 

Sympathetic fibres very resistant to injury

- sweat preservation 

- 20+ magnification lens 

 

Management

 

Outcome Factors 

 

General

- age of patient / most important / < 30 best prognosis

- level of injury (proximal worse than distal)

- health of patient

- time delay to repair

- pure sensory nerves do better than mixed nerves

 

Local

- cut or crush

- single or double level

- surgeon factors

- nil gap, no tension on repair

 

Contraindications to Repair

 

Noncompliant patient

Elderly

Hopeless outcome

Insignificant nerve eg SRN -> surgery to avoid neuroma

Insufficient skills

 

Types of Repair

 

1.  Direct

 

Epineurium repair without tension

 

Primary repair

- best chance of fascicular matching / best fit

- minimal retraction & gap formation

- historically best results

- 8/0 or 9/0 nylon

 

Fascicular Repair

 

Not usually indicated except

- distal 1/3 forearm median nerve

- distal 1/3 forearm ulna nerve

- sciatic nerve in thigh

 

Approach

 

Median nerve

- release PT and FDS radial insertion

- can transpose anterior to pronator and FDS

 

Results

 

Rujis et al Plastic Recon Surg 2005

- meta-analysis

- age > 40 / proximal lesions / delay to repair poor prognostic indicators

 

2.  Nerve Grafting 

 

Indications

- gaps > 2.5 cm

 

Options

- cable graft

- vascularised graft

 

Cable graft

 

Graft options

- Sural / MCNF / LCFN / Saphenous

 

Vascularised graft

 

Technique

- mobilise on BV pedicle

 

Advantage

- faster recovery

 

3.  Neural tubes

 

Description

- absorbable synthetic tubes

- epineurium sutured to each end of tube

- nerve fibrils grow into and along tubue

 

Advantage

- tension free repair

 

Results


Aberg et al J Reconst Plast Aesthet Surg 2009

- RCT of epineural repair v tube in sharp distal median and ulna nerve injures

- no difference between two groups

 

3. Nerve Transfer 

 

4. Neuroma 

 

Resect, diathermy & bury nerve end deeply in good tissue not bone 

 

 

Tendon Transfers

Median & Ulna Nerve

IssuesMedian and ulna nerve injury

 

Extremely difficult

- goals of rehab must be realistic

- limited number of donors

- static procedures more prominent

- fusions, tenodesis and capsulodeses must be used

 

Goals

 

1.  Thumb Opposition

 

EIP to APB and EPL 

- via pulley around Pisiform and FCR

- alternative is Palmaris longus or ADM

 

2.  Thumb Adduction 

 

BR / ECRB + PL graft to P1

- via base of MC III as Adductor

 

3.  Thumb to index tip pinch

 

APL slip with free graft to 1st dorsal interosseous

 

+/- Arthrodesis thumb MP

 

4.  Thumb to LF tip pinch

 

EDM to deep transverse lig

EDC to little must work

 

5.  Power Flexion of fingers 

 

ECRL to all 4 fingers

 

Technique

- using 4 tail graft to lateral sheath or A2 pulley via lumbrical path

 

Alternative

- free gracilis graft

- into FDP

- insert vascularized ulna graft to power

 

6.  Sensation median nerve

 

Superficial radial nerve translocation

Median Nerve

Aetiology

 

High Lesion

- elbow fracture or dislocation

- forearm fracture

- penetrating forearm wound

 

Low Lesion

- laceration at wrist

- distal radius fracture

- carpal dislocation

- entrapment in carpal tunnel

 

Clinical Features

 

1.  Low Lesion

 

A.  Loss Thumb function

- paralysis of APB & Opponens 

- variable FPB

- 1/3 have enough opponens power not to need transfer

 

B.  Parasthesia Radial 3 1/2 fingers and palm

 

2.  High Lesion

 

Above +

 

C.  Loss flexion index and middle finger

- lose FDS IF / MF / RF / LF 

- lose FDP to IF / MF

 

D.  Unable to flex thumb IPJ

- FPL

 

E. FCR + PT 

 

3.  Anterior Interosseous Nerve Palsy

 

Benediction sign

- loss FDP & FPL

- index finger and thumb straight

- middle finger is flexed due to quadriga of MF / RF

 

Weakness of pronation

- pronator quadratus

 

No thenar weakness or sensory loss

 

Management

- thumb: BCR to FPL

- IF / MF: FDP buddy to RF / LF / ECRL to FDP / fuse DIPJ

 

Management

 

Initial

 

Open injury

- Explore & repair

 

Closed injury

- Reduce fracture or dislocation

- Explore if fails to improve after 3/12

- NCS / EMG first

 

Physiotherapy

 

Maintain Joint ROM / Prevent Contractures

 

Goals

 

1.  Flexion IF / MF

- ECRL to FDP IF / MF

 

2.  Flexion RF / MF

- fusion DIPJ or

- buddy to RF / LF FDP

 

3.  Thumb IPJ flexion

- BR to FPL

 

4.  Thumb Opposition

- EI to APB or

- RF FDS to APB

 

4.   Sensation thumb & radial side IF 

- for pinch grip

 

Oppensplasty

 

High median nerve / Extensor indicis to APB

 

Harvest EIP

- incision over index MCPJ

- EIP divided with some extensor hood

- hood repaired

 

2nd incision over dorsum of hand 

- free EIP from EDC

 

Incision over dorsoulnar wrist 

- displace tendon ulnarward

- tendon passed subcutaneously ulnar aspect of wrist to pisiform which acts as a pulley

 

Tunnel across palm to thumb MCPJ

- interwoven into APB & EPL tendon

 

Low Median Nerve / Opponensplasty with RF FDS

 

Reason

- have strong Adductor Pollicis / 1st dorsal interosseous / EPL 

- they will overpower a weak transfer

 

Technique

- loop of FCU at pisiform for pulley for donor

- pass donor through loop 

- tunnel subcutaneously across palm & attach to tendon APB

Principles

Rule of 13 S's 

 

In a Sensible patient, I will transfer a

- Strong, Sacrificeable, Synergistic tendon with Sufficient excursion

- Straight through a Scarless, Stable bed, Subcutaneously

- across a Supple, Sensate joint

- to achieve a Single function by Securing distally

 

Patient

- Sensible

 

Tendon

- Strong (will lose 1 grade of power)

- Sacrifice able

- Synergistic

- Sufficient excursion

 

Surgery

- Straight

- Subcutaneous

- Straight pull

- Secure distally

- Single function

 

Joint

- Supple

- Sensate

- Scarless

 

Definition

 

Tendon transfer

- tendon of a functioning muscle is mobilised, detached or divided

- reinserted into a bony part or into another tendon

- to supplement or substitute for the action of the recipient tendon

 

Tenodesis 

- the detachment of a tendon & its attachment across a joint

 

Tendon Graft 

- when proximal & distal ends of a tendon are transected

- interposed into another tendon pathology

 

Indications 3R's

 

1. Replacement for lost function

- nerve injury 

- neurological disease 

 

2. Replacement of ruptured or avulsed tendons

- RA

- EPL in wrist fracture

 

3. Restoration of balance to a deformed limb

- Cerebral palsty

- stroke

 

 

 

 

Radial Nerve

Issues

 

1. Loss of wrist extension

2. Loss of finger extension

3. Loss of thumb extension

 

Aetiology

 

High lesion (loss of wrist extension)

- humeral fracture (Holstein Lewis)

- compression (Saturday night palsy)

 

Low lesion (PIN - wrist extension intact)

- fracture / dislocation elbow

- trauma / laceration

- iatrogenic - ORIF proximal radius

 

Clinical Features

 

High lesion

- triceps weakness uncommon (lesion usually past triceps innervation)

- wrist drop (ECRL, ECRB)

- inability to extend MCPJ (EDC)

- inability to extend thumb (EPL, EPB)

- sensory defect in anatomical snuffbox

 

Low lesion

- triceps intact

- wrist extension ECRB / ECRL intact

- no sensory deficit

- inability to extend MCPJ (EDC)

- inability to extend thumb (EPL, EPB)

 

Splints

 

1.  Radial Splint / Lively splint

- rubber bands & outrigger

- bands replace EPL / ECRB / EDC

 

2.  Simple static extension splint

- passive ROM to maintain supple joints

 

Investigation

 

NCS at 3/52 

- SNAP intact - neuropraxia

 

EMG at 3/12

- no reinnervation potentials

- poor prognosis

 

Options

 

1.  Explore at 4/12 if no recovery

 

Terzis et al Plast Recon Surg 2011

- surgical repair in 35 radial nerves

- 77% good outcome

 

Lee J Hand Surg Am 2008

- sural nerve grafting of high radial nerve injury

- 80% good or excellent results in regards motor function

 

2.  Tendon transfers

 

Indications

- no recovery at 6 - 9/12

- usually 1 mm / day

- should see ECRL by 6 months

 

Tendon Transfers

 

Goals

 

1.  Wrist Extension / ECRB

 

Pronator Teres

 

2.  Digit Extension / EDC

 

A. FCU

 

Problem

- is the most important wrist flexor

- only ulnar deviator / may result in radial deviation

 

B.  FDS middle finger

 

C.  FCR

- many authors favour 

- gives strong grasp 

 

3.  Thumb Extension / Abduction

 

A.  PL to EPL 

- line of pull via 1st dorsal compartment

- works well as gives some abduction

 

B.  FDS to RF (if no PL)

- can pass through intra-osseous membrane or tunnel subcutaneously

 

High Radial Nerve Transfers

 

Basis is use of PT for wrist extension

 

Jones Transfer

1.  PT to ECRL / ECRB

2.  FCU to EDC

3.  FCR to EPL (+ EPB & APL)

 

Problem is that both wrist flexors are transferred

- loss of FCU may lead to radial deviation

 

Brand Transfer

1.  PT to ECRB

2.  FCR to EDC

3.  PL to rerouted EPL

 

Problem 

- PL absent in 20% 

- alternative FDS RF / MF

- take through interosseous membrane or tunnel subcutaneously

 

Boyes

1.  PT to ECRL / ECRB

2.  FCR to EPB & APL

3.  FDS MF / EDC

4.  FDS RF / EPL & EIP

 

Technique Brand Transfer

 

Set up

- tourniquet

- arm table

 

Incisions

 

1.  PT incision

- over insertion on midportion radius

- dissect between ECRL and ECRB

- take entire periosteal insertion off radius

- need to keep long

 

2.  FCR / PL incision

- distal volar incision

- take both tendons as distal as possible

 

FDS RF

- make incision in palm over A1 pulley of RF

- if need FDS to RF must take proximal to bifurcation

 

3.  Dorsal incision

- proximal to extensor retinaculum, expose EDC and EPL

 

Transfers / Tensioning

 

1.  PL to EPL

- tunnel PL / FDS subcutaneously under SRN to EPL

- place thumb abducted and extended

- pulve taft weave

- through tendon 4 times at 90 degrees to each other 

- 4.0 ticron stitches at each pass

- check tension

 

2.  FCR to EDC

- pass FCR through all 4 tendons of EDC

- may need to take through EDMB

- check tension

- fingers should be in cascade in wrist flexion

- full extension with wrist extension

 

3.  PT to ECRB

- PT passed through ECRB with wrist in full extension

- again check tension

 

Post op

 

0 - 4 weeks splint

- wrist and MCPJ extension

- active finger extension (DIPJ, PIPJ)

 

4 - 6 weeks

- active MCPJ extension

 

Wrist flexor to finger extensor

- teach patient to flex wrist & extend fingers

- after a while they can extend fingers without flexing fingers

 

Pin Palsy Transfers

 

Wrist extension not required

 

Transfers

- FCR to EDC

- PL to EPL

 

 

 

Ulna Nerve

Aetiology

 

Low Lesion (Below Elbow)

 

Injury usually at wrist

- laceration at wrist

- fenetrating forearm wound

 

Ulna nerve laceration wrist

 

High lesion / Above elbow

 

Injury usually at elbow

- elbow fracture / dislocation

- compression (GA) 

- tardy ulna palsy

 

Low Lesion

 

1.  Claw hand deformity

 

Characteristics

- hyperextension all MCPJ 

- flexion of IPJ of Ring & Little fingers

 

A.  Absent lumbricals - loss of MCPJ flexion / IPJ extension to RF & LF

 

2.  Unopposed MCPJ extension - EDC 

 

3.  IPJ flexed by long flexors - less marked in high lesion because ulnar FDP paralysed

 

2.  Loss of interossei 

 

Weak finger abduction / adduction

Positive Froment's sign

Hypothenar & Interossei wasting

 

Froment's

 

3.  Numbness of ulnar  1 & 1/2 fingers

 

May have numbness of ulnar dorsum of hand

- depends on level of lesion

- if forearm, take out dorsal branch ulna nerve

 

High Lesion


Above +

 

A.  RF / LF FDP loss

- ulna paradox with less clawing 

 

B.  FCU weak

- weak wrist flexion

 

Goals

 

1.  Restore pinch / thumb stability

- thumb adduction (interposition to BR/ECRB)

- index abduction (EPB to 1st Dorsal Interossei)

 

2.  Correct MCPJ clawing

 

Management Low Ulna Palsy

 

1.  Thumb adduction

 

No donor long enough

- FDP LF tendon to BR / ECRB

 

Technique

- need interposition graft  i.e. FDP to LF)

- graft fixed to base P1 / normal insertion

- tendon passed along a line form base of MC III /  line of pull of Adductor

- bring out through dorsum between III and IV MC's

- attach to donor tendon BR or ECRB

 

2.  Index Finger abduction

 

EPB to 1st dorsal interossei

 

3.  Clawing of MCPJ

 

Goal

 

Prevent hyperextension of MCPJ's

- Want to create FFD

 

Options

 

Static

- Zancolli Capsulodesis / volar plate advancement

 

Dynamic

- reconstruction lumbricals

- split MF FDS / ECLR into 4

 

Zancolli Capsulodesis 

 

Transverse palmar incision

- each A1 pulley opened

- flexor tendons retracted

 

Volar plate raised as distally based flap & advanced proximally

 

Finger flexed to 20°

- volar plate sutured to new position

- mild FFD MCPJ created

 

Management High Ulna Palsy

 

1. FDP to ring and little

 

Buddy to middle FDP

 

Problem

- FDP flexes IPJ's before MCPJ's

- this unopposed flexion of IPJ can push object out of palm

 

2. FCU

 

Split FCR to FCU