BPI & Peripheral Nerve Injuries PDF

Susan said she wont ask brachial plecus but might be linked to work question OT for brachial plexus injuries The motor unit peripheral nerve goes to...

Susan said she wont ask brachial plecus but might be linked to work question OT for brachial plexus injuries The motor unit peripheral nerve goes to end organ where there is a motor and sensory function - result of injury or injsult at the peripheral nerve Basic functional unit of peripheral nervous system - injury at spinal cord is UMN lesion Consists of 4 elements: - median nerve lesion on right side clinical picture → Cell body of the motor neuron (in anterior horn of spinal cord) only looks at whats inevrated by theat nerve → Axon of motor neuron and distally that is affceted → Neuromuscular junction → Muscle fibres that are innervated by the neurons Anatomy overview of the brachial plexus  Randy travis Drinks M - Musculocutaneous nerve Cold beer A - Axillary nerve R - Radial nerve M - Median nerve U - Ulnar nerve this is NB for clinic ANATOMY REFRESHER: MYOTOMES: C5 supplies the shoulder muscles and the muscle that we use to flex our elbow. C6 is for extending the wrist. C7 is for extending the elbow. C8 flexing the fingers. T1 abducts the fingers If injury is at the level of the spinal cord = everything below will be affected (everything above will be unaffected) If it’s not at the level of the spinal cord = injury is isolated ANATOMY REFRESHER: DERMATOMES: Brachial plexus injuries (lesions) Avulsion: nerve has ruptured & pulled out of the spinal cord (no possibility of repair = total loss) Rupture: injury along the course of the nerve (can be repaired) Neuroma: conglomeration of nerve endings that are growing outside of its normal border = causes disruption of conduction (can be repaired)  Neuropraxia: compression of the nerve along its course (will heal by itself over time = the best prognosis) Upper trunk BPI (C5, C6 nerve fibres) The muscle of the shoulder and the elbow are affected. Hand movement is retained but inability to place the hand for function because there is no shoulder function & there are limitations in elbow function. Paralysis and atrophy occur in the deltoid, brachialis, biceps and brachioradialis muscles. Arm hangs in internal rotation and adduction of the shoulder. Elbow is extended, forearm in pronation, and the wrist flexed, resulting in the “waiters tip position” Called Erb-Duchenne syndrome. Also referred to as Erb’s palsy (specifically in babies) → Common obstetrical BPI. Lower trunk BPI (C8, T1 nerve fibres) Traction caused by a strong upward pull on the upper limb when it is in an abducted position can cause this (such as motorcycle accident) Wrist and finger flexion and abduction and adduction of the fingers are affected. Paralysis and atrophy of the wrist flexors and intrinsic muscles of the hand. Can place the hand for function but no intrinsic hand function (cannot use hand) Called Klumpke’s (Dejerine-Klumpke) syndrome or Klumpke’s palsy. Total BPI (all fibres involved) Devastating injury – cannot be repaired Completely flail upper limb No sensation Often experience a lot of pain Kerer’s palsy Can involve Horner's syndrome → Horner's syndrome, also known as oculosympathetic paresis, is a condition characterized by a combination of symptoms that result from damage or disruption of the sympathetic nerve pathway. The sympathetic nervous system is responsible for regulating involuntary functions of the body, including pupil dilation, sweating, and certain muscle movements. → Horner's syndrome typically presents with a triad of symptoms on one side of the face: 1. Ptosis: Drooping of the upper eyelid occurs due to the paralysis or weakness of the muscles that elevate the eyelid. 2. Miosis: Constriction of the pupil is observed, causing the affected pupil to appear smaller than the other pupil. This occurs because the sympathetic nerves that control pupil dilation are affected. 3. Anhidrosis: Decreased or absent sweating on the affected side of the face or neck is a common feature. The sympathetic nerves that regulate sweating are impaired. Prognosis is poor – especially if with Horner’s syndrome (because then it is likely that the entire brachial plexus was avulsed from the spinal cord) MUSCLE WASTING: MUSCLE WASTING & STIFFNESS: STIFFNESS & CONTRACTURES: OT assessment History Skin and soft tissue Postural attitude – how does the person carry the affected limb Sensibility ROM Muscle Testing Pain Assess limitations in activity and participation OT intervention of BPI Passive ROM to maintain joint mobility Tactile stimulation to upper extremity to increase awareness Proprioceptive stimulation to the upper extremity Bilateral hand use Slings and splints Retrograde massage (oedema management) Addressing limitation in activity and participation  OT for peripheral nerve injuries “The importance of a normally functioning hand needs no emphasis, whether in earning a living, practicing a hobby or allowing independence in daily activities. The hand is capable of the strongest grasp and the most delicate touch; its rich and complex sensory innervation allows the finest judgement of texture, volume and temperature. The value of a strong and well-coordinated hand in such activities as writing, paining and manipulating tools is obvious. Less obvious perhaps is the extent to which the hand is a reflection of personality and a vital organ of expression. One has only to consider the manual signs and attitudes of an oriental dancer, the benediction of a priest, the gestures of a conduct or a Gallic raconteur, to realize how much more is the hand than a prehensile and sensory tool. Injury, disease or surgical interference, therefore, do much more than interfere with grip or touch; they attack the personality itself.” (Parry 1981) The motor unit Basic functional unit of peripheral nervous system Consists of 4 elements: → Cell body of the motor neuron (in anterior horn of spinal cord) → Axon of motor neuron → Neuromuscular junction → Muscle fibres that are innervated by the neurons The peripheral nerve: macroscopic view A neuron comprises a cell body, dendrites and an axon. The axon connects the neuron to the end organ. A nerve consists of axons, which are bundled together into groups called fascicles. Each fascicle is wrapped in a layer of connective tissue called the perineurium. The entire nerve is wrapped in a further layer of connective tissue called the epineurium. Schwann cells surround the axonal projections, producing myelin, which acts as an electrically insulating layer to aid conduction along the nerve. Wallerian degeneration Exam question: what is the process that occurs after nerve lesion: When a nerve injured a series of events start, know as Wallerian degeneration – named after Augustus Waller who first described this in the 1800’s  Trauma to a peripheral nerve initiates a sequence of events, proximally and distally. Wallerian degeneration starts in the in the distal nerve segment when the distal axon is separated from the cell body of the neuron (Allodi et al., 2012). This leads to a subsequent process of degeneration, resulting in cell death and atrophy of the denervated end organs (Terenghi et al., 2011). This occurs almost immediately after injury and acts as a process of clearing away debris in preparation for re-innervation of the distal segment. Sprouting of new axons growing from the proximal nerve segment into the distal nerve segment occurs as a result of various neurochemical signals When passing the site of injury, regenerating axons must travel through the correct endoneurial tubes so that they journey back to their original target organs: the sensory or motor receptors. However, it is common for misdirection to occur and this influences the outcome after a nerve injury. The level of injury is also a significant factor, with higher-level injuries requiring axons to travel a longer distance and thus take more time to reach the target organs. This, together with a slow rate of nerve regeneration, which typically occurs at 1 to 2mm/day, means that recovery from a nerve injury can take many months or years (Sulaiman and Gordon, 2013). The mechanism of a nerve injury is significant and different types of nerve injuries require different types of treatment. Types of injuries Question: what are the 3 classifications of peripheral nerve lesions  With damage to peripheral nerves, both the motor and sensory functions are affected which results in deformity and sensory loss. Recovery depends on the structures which have been affected, as well as the extent of the injury to the nerve. NEUROPRAXIS: A local conduction block as a result of a compressive force. This disrupts the conduction of electrical signals. However, as the axons remain intact, recovery from neuropraxia injuries is possible without surgery. All structures are intact Axons’ conduction Sensory – incomplete Motor – usually complete Recovery is spontaneous and complete – total recovery within 6 weeks  This process can take weeks or months and occurs when myelin repair processes restore local excitability of nerve fibres Best prognosis AXONOTMESIS: injuries where axons have been disrupted, but the epineurium and perineurium are intact. This allows for outgrowing axons to find their way back to the correct targets and therefore recovery is also possible without surgical intervention Usually as a result of traction or direct trauma Axons are damaged and sheath is intact Wallerian degeneration will follow with spontaneous recovery  Wallerian degeneration of the distal parts occurs and therefore recovery time is greater, as it corresponds to the time taken for axons to regenerate distally Prognosis is usually good, but recovery may be incomplete due to scarring and insufficient re- innervation NEUROTMESIS: A complete transection of the nerve and its surrounding tissue, requiring surgery to restore its continuity. These types of nerve injuries require the longest recovery time and also have the added challenge of axonal regrowth across a scar or suture gap. All structures are damaged – both the axon and sheath are severed Recovery is only possible with nerve transplant or repair Has the longest recovery period Poor prognosis Causes of injuries Avulsion: Nerve roots are pulled from the spinal cord – proximal to dorsal root ganglion. Cannot be repaired. Compression and traction: A large section of the nerve may be damaged beyond repair. Crush / pressure injuries 1. Laceration 2. Gunshot wounds 3. Traction injury 4. Ischemia (Volkmann’s) 5. Compression 6. Radiation 7. Bone fractures Nerve degeneration & regeneration DISTAL NERVE END PROXIMAL NERVE END Undergoes Wallerian Degeneration Degeneration also occurs Regardless of whether the nerve is repaired Involves 40 to 50 percent of the nerve fibres primarily or not Surgical repair Epineurium repair (A) → Epineurium repair is performed during nerve surgery to ensure proper healing and protection of the nerve. → The procedure involves carefully reapproximating and suturing the torn or damaged epineurial tissue to restore its integrity. → The goal of this repair is to create a stable environment for the healing process and prevent the nerve from being exposed to further injury or stress → Corresponding nerves rejoined/found themselves Fasicular repair (B) → Peripheral nerves consist of multiple individual bundles of nerve fibers called fascicles. → Each fascicle contains a group of nerve fibers surrounded by a connective tissue called the perineurium. → In cases where a peripheral nerve is damaged or severed, the fascicular repair technique is employed to restore the continuity and function of the nerve. → Lengthy prodedure  → If the nerves are misdirected – can affect the outcome Nerve graft – sural nerve Prognosis The recovery of a nerve injury is usually difficult to predict, but the following should be considered: 1. Age: o The recovery in children is better than in young adults – the reason for this phenomenon is unknown. o In adults, recovery never reaches its pre-morbid level, except in the case of minor injuries. o The result in patients over 40 years is inferior to that of younger patients 2. Nature of injury: o The recovery in clean lacerations is better than in crush, traction and gunshot injuries. o Avulsion injuries are potentially more harmful – especially if avulsion has occurred in all the nerve roots. o The recovery in distal injuries is better as in proximal injuries.  The higher (more proximal) the level of injury, the more difficult the regeneration of the axons. o In high level injuries, there is a combination of sensory, motor and sympathetic fibres and the axons may therefore recover incorrectly. o In higher level injuries the end-organs remain without any innvervation which results in atrophy of the muscles 3. Timing of the surgery 4. Motor versus sensory recovery: o Muscles that lose their innervation can be re-stimulated for up to three years, but atrophy and fibrosis may however prevent re-innervation. o Sensory nerve ends degenerate at a more rapid rate than those of muscles and a delay of more than six months from injury to repair negatively affects the potential for recovery. o A delay of surgical repair of the nerve also affects the recovery – recovery can still occur up to two years and some researchers are of the opinion that a plateau of recovery-rate is only reached after three to four years. → Injuries at shoulder level: 2 – 3 year recovery period → Injuries at elbow level: 1 year recovery period → Injuries at wrist level: 3-6 month recovery period o The surgeon can repair the nerve in various ways: → Epineurium repair - sutures are inserted through the epineurium → Group fascicular repair – co-optation of individual fascicle groups o If the nerve is placed under any tension during the repair it has a poor chance of recovery. Rate of healing Post-operative occuptational therapy (following a nerve repair) A primary nerve repair is performed 1 to 3 weeks after injury and a secondary nerve repair 3 to 6 weeks after injury. After 6 weeks, a nerve transplant will probably have to be performed. 1. Immobilistion for ± 2 – 3 weeks with the hand in a position of least tension on the nerve. The reason for this is that the recovering nerve should never be stretched as this will hamper regeneration of the axon and lead to the development of scar tissue. 2. Latent period of ± 3 – 4 weeks, after which the nerve will start growing at a rate of 1 mm per day. 3. Prepare the patient for these events and encourage him not to lose hope once atrophy of the muscles starts occurring. Counter any tendencies of the patient to reject the affected limb and to stop using it. 4. The occupational therapist should not apply too much traction on the nerve. 5. Splinting – substitute for weak muscles. Splints should be removed or adapted as soon as muscle strength returns. The unnecessary use of splints or assistive devices will delay full physical recovery. 6. Patients should learn the correct movement patterns to avoid trick movements. 7. Use visual precautionary measures for sensory loss e.g. burns, pressure, friction. Do sensory re- education as soon as protective sensation starts returning. 8. Assistive devices / new methods for performing ADL so that independence may be regained as soon as possible. 9. Return to work as soon as possible – with or without adaptations. 10. Muscle strengthening – maintain strength in the initial stages and start strengthening as soon as strength returns. 11. Weak muscles will contract with less effort if the joint is passively placed in the desired position than when they have to move the joint through the full range of motion. 12. Start with isometric movement followed by isotonic movement. 13. Eliminate gravity – with gravity – light resistance – full resistance. 14. Carefully selected activities require the cooperation of muscles and this will facilitate improved coordination and muscle strength. 15. Activity sessions may be prolonged as the patient’s endurance improves. 16. Maintain muscle strength in unaffected muscles. 17. Maintain the ROM – maintain as much as possible in the initial stages and start improving ROM as muscle strength starts returning. 18. Initial activities should be light and large. 19. Bilateral activities should be used to facilitate cross-stimulation, e.g. table games, computers. 20. Prevent deformities – prevent over-stretching and contractures. 21. Ensure good positioning (through the acute and regenerative stages). 22. Maintain the arches in the hand. 23. Adjust exercises and activities in accordance with improvement. 24. Re-assess regularly. 25. If no further recovery occurs, the patient should be taught how to compensate for any loss. 26. Recommend permanent assistive devices. 27. Recommend new, more suitable employment. 28. Preparation for surgery and treatment afterwards SPLINTING & ASSISTIVE DEVICES: Maintain PROM & hand arches Prevent deformities Substitute for weak muscles Remove as soon as muscle strength returns – may compromise full recovery  Grade eg. Radial nerve palsy Occasionally permanent devices PRECAUTIONARY MEASURES: Prevent muscle fatigue Prevent trick movements – so that the muscle is used when there is return of function Prevent excessive stress on the nerve Prevent contractures OT ASSESSMENTS THAT MAY BE PERFORMED: General background information Observation → condition of the wound after 7 days. → oedema after 7 days Muscle testing (Manual muscle testing) ROM - after 10 to 14 days (goniometry) Goniometer Sensation - 6 to 8 weeks before difference will be observed Hand function → Smith hand function test → Jebsen hand function test → Disabilities of the arms shoulder and hand questionnaire Functional assessment → Work → LTA → Personal management Psychological assessment Guideline for the progression on post-operative treatment in relation to the affected limb ULNAR AND MEDIAN NERVE INURY AR WRIST LEVEL: 0 - 6 days o In plaster cast with wrist in 30° flexion 7 days o Dorsal protection splint with wrist in 30° flexion during the day and at night o If the nerve has been damaged in the proximal half of the forearm the elbow should also be splinted in 90°flexion. o In a median nerve injury a C-bar is added. 2 to 3 weeks o Sutures are removed 2 weeks post-operatively. o Active and passive flexion of the IP joints can commence, but only with the wrist in flexion. o The splint is still worn during the day and at night. o Start with scar management. o Very light activities. o Full support. o No stretching of the repaired nerve. o No stretching of weak muscle tendons. o Place body part in optimal position to enable muscle action once movement starts to return. o No static positions. o Avoid trick movements. o Temporary assistive devices. 3 weeks o Wrist is now placed in the splint in the neutral position. o If the patient complains of a burning or pins and needles sensation, it gives an indication of how far the wrist can be extended. 4 weeks o Range of motion exercises of the wrist / elbow may commence. 5 weeks o Splint is only worn at night and in in when in large crowds. o Children should wear the splint for another week. o Use activities that offer little resistance – no muscle power may be used yet. o Support and positioning should still be sufficient. o Static positions should not be sustained for prolonged periods.. o Ulnar nerve injuries should receive an MP extension block splint and median nerve injuries should receive a short, opposition splint. 6 weeks o Wrist extension with the fingers in extension may commence. o Sensation can now be assessed. o Start with sensory re-education and / or desensitization when indicated. 7 weeks o If stiffness has set in, a dynamic traction splint may be issued to the patient. o A lot more resistance can be applied. o Activates may be attempted without the splint or support. o Trick movements now become a bigger risk. o Static groups can now be used safely. o Grade muscle strength to full resistance according to the Oxford scale. o Improve muscle strength and hand dexterity. It may take up to 18 to 24 months before full strength is regained. 9 to 12 weeks o Attend to muscle strength and work rehabilitation. RADIAL NERVE INJURY IN, AND PROXIMAL TO THE FOREARM: 0-6 days o Rest in plaster cast with wrist in extension. 7-14 days o Plaster cast is removed. o Dynamic MP extension splint with the wrist in the neutral position, during the day and at night. 2 weeks o Sutures are removed.. o Start with passive and active range of motion of IP joints whilst keeping the wrist and MP joints in extension. o Massaging of the scar and / or silicone gel. 4 weeks o Start with range of motion of the wrist with the fingers in extension. 7 weeks o A dynamic traction splint can be applied if joint stiffness has set in. 9 - 12 weeks o Start with muscle strengthening and work rehabilitation. NERVE TRANSPLANT 0-9 days o Plaster cast with the wrist placed in the neutral position and the elbow in flexion. 10 days o Sutures are removed. o Start with light active and passive range of motion. 4 weeks o A Tinel’s sign should now be observed.. o Start with more progressive active and passive range of motion. 5 weeks o Treatment as for a normal nerve repair can now commence. Median nerve ANATOMY: Formed in the axilla from the joining of the lateral root of the lateral cord and the medial root of the medial cord of the brachial plexus. Runs close to the N Ulnaris in the upper half of the upper arm. Runs on the lateral side of the brachial artery to the centre of the upper arm and transverses to the medial side of the brachial artery – is in contact with M Brachialis. Anterior elbow – runs medially to the artery that runs on the medial side of the biceps tendon.. Branches to pronator teres, FCR and runs through the two heads of pronator teres. 5 – 8 cm distal to the lateral epicondyle – divides into the anterior interosseus branch that innervates those muscles anterior to the interosseus membrane, namely FPL, FDP 2 and 3 and pronator quadratus. Runs through the superficial and deep flexors and innervates FDS and palmaris longus. ± 5,5 cm proximal to the radial styloid process, it divides into the cutaneous branch that innervates the skin in the proximal palm over the 1, 2 and 3rd metacarpal. At the wrist the nerve runs through the carpal tunnel and divides into a branch that innervates the thenar muscles, namely Abductor pollicis brevis, Opponens Pollicis and FPB (opp head), as well as branches to the radial 2 limbricals and volar side of 1, 2 and 3, the radial side of 4 and the dorsal side of the fingers’ middle and distal phalanges. INJURIES: Humerus fracture Dislocation of the elbow Distal radius fracture Anterior dislocation of the lunatum in the carpal tunnel Lacerations due to stab wounds or glass cuts, especially at the wrist. Compression in the forearm and wrist. CLINICAL PICTURE OF INJURY: Injury at wrist level o Atrophy of thenar eminence o Loss of opposition o Thumb is held against index finger – EPL is not balanced by APB and Opp Poll. o Hyperextension of MP of index and middle finger o Sensory loss o Ape hand Injury at elbow and / or neck o Loss of finger flexion, wrist flexion and the pronators o Hyperextension of wrist o “Sign of benediction” when patient attempts to make a fist Functional o Inability to pression and power grip o Loss of fine and inferior pinch o Unable to grasp securely o Incoordination due to loss of sensation o Unstable thumb o Grips with FPL and Add Poll against radial side of the index finger (low lesion). o Writing is difficult due to the loss of flexion of index finger and thumb. RECOVERY: Motor: → FPB: 70 – 90 days → APB: 72 – 140 days Sensory: → 2-point discrimination takes years to recover. TREATMENT: Activities: o Activities requiring 3-point pinch and pronation: → Picking up light objects – grade size and weight → Macramé → Threading and stamping in leatherwork → Pinch pot in pottery → Table games – solitaire → Improve finger coordination – games, computer → Final stages – static activities – needlework, writing, wood carving → Sensory stimulation and re-education o Precautionary measures because of the sensory loss Splints: o Aims → Assist with function in the thumb for fine pinch grasp because of loss of thenar muscles → Prevent contracture of the first web space due to the shortening of the thumb adductors → Correct above-mentioned contracture if already developed  → Prevent hyperextension of the MP if index finger is clawing – occurs less often o Types of splints: → Thumb opposition splint – can also maintain web-space → Web space splint – prevents stress on the collateral ligament of the MP of the thumb. Provide space for rotation of the first MC in a position of pronation. → Serial splinting – especially for contractures – keep web space in maximum abduction at all times. Only remove the splint for other exercises or ADL. Trick movements o Pinch grip with FPL and Add Poll against the radial side of the index finger. Ulnar nerve ANATOMY: The largest of two terminal branches of the medial cord of the brachial plexus. Runs distally and anteriorly to triceps on the medial side of the brachial artery and N Medianus At approximately the middle of the arm, the nerve runs through the medial inter- muscular septum and progresses on between the septum and the medial head of triceps. Enters the forearm between the medial epicondyle of the humerus and the olecranon.. Nerve is superficial here and can be easily palpated. Runs between the heads of FCU and innervates the muscle as well as FDP IV and V. Proximal to the pisiform, it divides into a palmar cutaneous branch which innervates the ulnar side of the proximal palm and into dorsal cutaneous branches that innervates the ulnar half of the dorsum of the hand as well as half of 3 and the whole of 5. The nerve runs through Guyon’s canal through the wrist and divides into a superficial branch to 5 and half of 4, as well as motor branches  to the hypothenar muscles (Abductor digiti minimi, Opponens digiti minimi), dorsal and palmar interossei, lumbricals 4 and 5, Adductor Pollicis and the deep head of FPB. INJURIES Fracture of the medial epicondyle of the humerus. Fracture of the olecranon process of the ulna.. Lacerations with glass or knife – especially at wrist level. Compression in the forearm and wrist. CLINICAL PICTURE OF INJURY: Injury at wrist level o Inability of thumb to perform lateral pinch against gravity o Claw hand – MP hyperextension of ring finger and pinkie (as a result of over-action of ED and EDM and the loss of flexion in the medial 2 lumbricals) and IP flexion of the same fingers (as a result of FDP and FDS that are not counter-balanced by the interossei). o Index and middle fingers are unable to cross each other. High lesion o Loss of grip strength secondary to the paralysis of FDP in the ring finger and pinkie. o Weak flexion of the wrist due to FCU paralysis. Functional o Usually unable to hold a knife between index and middle finger. o Handwriting is difficult as a result of the loss of sensation on the ulnar side of the hand. o Reduced grip strength Verminderde greepsterkte. o Power grip is more affected than precision grip. o Patient is unable to keep his hand around an object. o Unable to lift the hypothenar eminence. o Loss of thumb pinch action due to the loss of Add Poll. o Precision grasp is affected as a result of the loss of the interossei. o Inability to fully extend fingers in preparation for picking up an object – claw hand. o Inability to fully flex fingers during a cylindrical or spherical grasp. o Loss of sensation. RECOVERY Motor → First sign is a flicker in ADM (81 days) – especially during opposition of the thumb towards the pinkie. → MP-flexion (140 days) → Ab- and adduction of the fingers ( 150 – 200 days) → Full function – axonotmesis 7 months; neurotmesis 2 years. Sensory → Light touch is experiences as a numb feeling and pain as light touch. → Tinel’s sign at level of regeneration. TREATMENT: Muscle action seldom recovers in the adult hand and intrinsic repair is often indicated. Activities o Activities requiring IP extension and thumb lateral pinch. o Woodwork o Rolling out clay for an item of pottery (salt dough can be used before pottery clay is introduced). o Early stages –activities where the entire arm is used. o Later on in recovery – improve grip with MP flexion, IP extension, thumb lateral pinch and opposition. o Drafts o Macramé o String-and-nail articles o Wood carving o Later – static grip – sawing o Handwriting may still be affected. o Sensory stimulation on the ulnar side of the hand. o Visual VSM Splints o Aims: → Forearm claw hand → Assist with grip and release through facilitation of IP extension and MP flexion. → Correct claw hand deformity if it has already developed. o Types of splints: → Static or dynamic MP flexion splints. → Prevent MP hyperextension → Allow for full finger flexion → Shouldn’t interfere with gripping o Dynamic and / or serial splints for contractures Trick movements o Adduction of thumb to index finger – FPL and EPL (loss of Add Poll) – “Froment’s sign”. o Flexion of IP of ring finger and pinkie with flexion of MP of these two fingers (loss of lumbricals 2 & 3). o Abduction of fingers - EDC (loss of Dorsal interossi) o Adduction of fingers with a slackening of the extensors and contraction of the long flexors. o Opposition of pinkie and thumb – IP of the pinkie flexes and compensates for ODM. Radial nerve ANATOMY: Extension of posterior cord of the brachial plexus. Largest branch of the brachial plexus. Gets nerve fibres from all the nerves of the brachial plexus (C5-T1). Enters the arm posterior to the brachial artery, medial to the humerus and anterior to the long head of triceps and innervates the triceps. In upper arm it innervates anconeus and runs via the groove to the radial aspect of the humerus. ± 10 cm proximal to the lateral epicondyle – runs through inter- muscular septum and exits in the anterior flexor compartment of the humerus. Runs between brachialis, brachioradialis, ECRL and ECRB and innervates all these muscles. At the elbow, it branches into the superficial radial sensory branch and deep posterior interosseus branch. Superficial sensory branch o Smallest of the two branches. o Progresses to the radial aspect of the forearm and becomes superficial at the distal half of the forearm. o Runs anterior to pronator teres.. o At wrist level, between Lister’s tubercle and the radial styloid, it provides terminal sensory branches to the dorsal aspect of the thumb and dorsum of 2, 3 and half of 4 up to the PIP joints. Deep post-interosseus branch o Innervates ECR. o Runs through supinator and then down into the forearm. o Innervates supinator, EDM, ECU, Abductor Pollicis Longus, EPL, EPB and EL. INJURIES: Humerus fracture – the nerve runs very close to the humerus, especially at the mid-humeral area. Pressure in the axilla (Saturday Night Palsy or crutches). Lateral head of triceps, 2 cm distal to the deltoid insertion – pressure on nerve. Dislocation or fracture of the elbow or radius. Compression at the level of ECRB. Compression at the level of supinator. CLINICAL PICTURE OF INJURY: Injury of post-interosseus branch o Weakness or paralysis of finger and thumb extensors as well as ECU. Injury at mid-humeral level o Total loss of wrist extension – drop wrist. o Loss of thumb and finger extensors. o Thumb in abduction. o Flexion of the IP joints.  o Increased wrist flexion. o Atrophy of muscles in the forearm.. Injury high up in the arm o Loss of elbow extension, wrist and finger extension as well as supination. Functional o Drop wrist results in weakened grip. o Reduced grip strength due to the loss of wrist stability during grasping. o Release action can be obtained through either wrist flexion or passively. o Unbalanced flexors at the wrist and fingers result in a dysfunctional hand. RECOVERY: Depends on the level of the lesion and varies from patient to patient. The return of normal grip only realizes after a few months. Sensory loss is generally not complete and recovers well. TREATMENT: Activities o Activity requirements include a stable wrist and grip as well as wrist and finger extension and supination. o Initially light activities: o Table games Macrame o Roll pottery techniques o As muscle strength improves, activities offering more resistance can be used. o Wheel-pottery Woodwork – sanding and polishing of wood for wrist extension. Printing activities o Improve hand dexterity. o ADL o Return to work within ± three weeks with splint. Splints o Aims: → Assist with grip and improve grip strength by providing a stable wrist in extension. → Position the hand for functional use.. → Prevent over-stretching of wrist extensors. → Correct wrist flexion deformity. o Types of splints: → Dynamic dorsal extension splint.  → Wrist, thumb and finger extension. - Wrist in 30-40° extension. - MP in neutral position. - Wear splint all day. - If it is the non-dominant hand that is affected, a dynamic splint is not always required and a wrist extension splint can be provided. → Dynamic and / or serial splint for contractures. Trick movements o Strong flexion of the wrist and fingers followed by relaxing can present as a contraction of the extensors. o Flexion of the MP occurs when the patient wants to extend because the intrinsic muscles provide extension of the IP and flexion of the MP joints. o Thumb IP extension cannot occur through palmar abduction of the thumb as a result of the accessory insertion of APB in the extensor apparatus. Precautionary measures 1. Prevent over-exertion of muscles.. 2. Prevent trick movements. 3. Prevent injuries due to the sensory loss. 4. Prevent too much stress on the nerve initially – this may rupture the repair site. 5. Prevent the development of contractures principles for treating PNI, MSK condition - sensation, muscle strengthening, ROM she wont ask - details on days - muscles expected to know median nerve injury - opposition ulnar nerve injury - claw radial nerve - unable to extend wrist