Axillary Nerve-AnatomyAxillary Nerve-Anatomy Arises from posterior cord of brachial plexus and runs alongside radial N behind Arises from posterior cord of brachial plexus and runs alongside radial N behind Axillary A, separating the latter form subscapularis muscle on the floor. At lower border Axillary A, separating the latter form subscapularis muscle on the floor. At lower border of muscle, it leaves radial N and turns posteriorly with the posterior humeral circumflex of muscle, it leaves radial N and turns posteriorly with the posterior humeral circumflex artery through quadrangular space to posterior aspect of humerus, where it divides into artery through quadrangular space to posterior aspect of humerus, where it divides into anterior and posterior branches. anterior and posterior branches. Posterior branch supplies to teres minor and posterior part of deltoid before it Posterior branch supplies to teres minor and posterior part of deltoid before it curves around the posterior border of deltoid to supply the skin over lower half of deltoidcurves around the posterior border of deltoid to supply the skin over lower half of deltoid (upper lateral cutaneous nerve of arm). The anterior branch proceeds laterally and (upper lateral cutaneous nerve of arm). The anterior branch proceeds laterally and anteriorly beneath the deltoid and in contact with surgical neck of humerus about 2 anteriorly beneath the deltoid and in contact with surgical neck of humerus about 2 inches below upper attachment of deltoid giving off numerous twigs to the muscle inches below upper attachment of deltoid giving off numerous twigs to the muscle throughout its course.throughout its course.

Axillary N injury-Clinical pictureAxillary N injury-Clinical picture Injury to main nerve in axilla or at surgical neck produces complete paralysis of Injury to main nerve in axilla or at surgical neck produces complete paralysis of deltoid with loss of abduction and anesthesia of small patch of skin over lower half of deltoid with loss of abduction and anesthesia of small patch of skin over lower half of deltoid (regimental badge area). First 20deltoid (regimental badge area). First 20ºº to 30 to 30ºº abduction is initiated by rotator cuff, abduction is initiated by rotator cuff, chiefly supraspinatus. Occasionally, with complete RD and atrophy of deltoid, the chiefly supraspinatus. Occasionally, with complete RD and atrophy of deltoid, the supraspinatus may hypertrophy in compensation and restore abduction.supraspinatus may hypertrophy in compensation and restore abduction. When the anterior branch is interrupted, the muscle anterior the point is When the anterior branch is interrupted, the muscle anterior the point is paralyzed. Partial muscle paralysis is frequently compensated by hypertrophy of paralyzed. Partial muscle paralysis is frequently compensated by hypertrophy of supraspinatus and activity of pectoralis major, especially with arm above the horizontal supraspinatus and activity of pectoralis major, especially with arm above the horizontal plane.plane.

Axillary N injury-TreatmentAxillary N injury-Treatment Prophylaxis consists of avoiding unnecessary extension of operative incisions Prophylaxis consists of avoiding unnecessary extension of operative incisions and rough handling of deltoid muscle. If the nerve is contused, spontaneous and rough handling of deltoid muscle. If the nerve is contused, spontaneous regeneration may take place in 4-6 months, during which time deltoid must be relaxed regeneration may take place in 4-6 months, during which time deltoid must be relaxed on abduction splint and light massage and electric stimulation given.on abduction splint and light massage and electric stimulation given. Daily active exercises are done to strengthen cuff muscles. Operative repair of Daily active exercises are done to strengthen cuff muscles. Operative repair of this nerve is exceedingly difficult and frequently impossible. Conservative treatment is this nerve is exceedingly difficult and frequently impossible. Conservative treatment is advised unless damage to main large nerve is evident. Operative exposures of shoulderadvised unless damage to main large nerve is evident. Operative exposures of shoulder should avoid muscle splitting incisions. If unavoidable, incision should be confined to should avoid muscle splitting incisions. If unavoidable, incision should be confined to anterior third of deltoid and not beyond 1 anterior third of deltoid and not beyond 1 ½½ inches distal to AC joint. inches distal to AC joint.

Axillary N injury-ArthrodesisAxillary N injury-Arthrodesis Complete deltoid paralysis, when not compensated by other muscle action, Complete deltoid paralysis, when not compensated by other muscle action, requires arthrodesis of shoulder. Trapezius and serratus anterior will raise the arm requires arthrodesis of shoulder. Trapezius and serratus anterior will raise the arm effectively.effectively.

Axillary N injury-Harmon OperationAxillary N injury-Harmon Operation When anterior portion of deltoid is paralyzed, muscle may be seriously When anterior portion of deltoid is paralyzed, muscle may be seriously weakened, particularly in forward flexion and humeral head may dislocate or subluxate weakened, particularly in forward flexion and humeral head may dislocate or subluxate anteriorly. This is corrected by transposing the posterior origin of functioning muscle to anteriorly. This is corrected by transposing the posterior origin of functioning muscle to new anterior position. new anterior position.

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Axillary N injury-Trapezius T TransplantAxillary N injury-Trapezius T Transplant Trapezius muscle insertion is transferred by fascia lata strip extension to deltoid Trapezius muscle insertion is transferred by fascia lata strip extension to deltoid tubercle. Prerequisite is good power in scapular muscles, including trapezius, serratus tubercle. Prerequisite is good power in scapular muscles, including trapezius, serratus anterior, pectoralis major, rhomboids and levator scapulae. Main contraindication is anterior, pectoralis major, rhomboids and levator scapulae. Main contraindication is subluxation of shoulder joint. subluxation of shoulder joint.

Axillary N injury-Biceps & Triceps TransplantAxillary N injury-Biceps & Triceps Transplant Tendons of short head of biceps and long head of triceps are fixed to anterior Tendons of short head of biceps and long head of triceps are fixed to anterior and posterior rims of acromion.and posterior rims of acromion.

Median N-AnatomyMedian N-Anatomy Formed from lateral divisions of 5Formed from lateral divisions of 5thth, 6, 6thth and 7 and 7thth cervical roots and medial divisions cervical roots and medial divisions of 8of 8thth cervical and 1 cervical and 1stst thoracic nerves. Enters axilla lateral to Axillary artery and lies thoracic nerves. Enters axilla lateral to Axillary artery and lies between MC N laterally and ulnar N medially. It descends in arm with brachial A and between MC N laterally and ulnar N medially. It descends in arm with brachial A and other nerves in a groove just medial to and slightly behind the biceps muscle and other nerves in a groove just medial to and slightly behind the biceps muscle and gradually crosses over in front of artery (rarely it crosses behind) until it lies medial to gradually crosses over in front of artery (rarely it crosses behind) until it lies medial to brachial A before it reaches elbow.brachial A before it reaches elbow. No branches are given off in arm. At elbow it lies deep to bicipital aponeuroses No branches are given off in arm. At elbow it lies deep to bicipital aponeuroses and median cubital vein. It enters forearm by passing between larger humeral and and median cubital vein. It enters forearm by passing between larger humeral and smaller ulnar head of pronator teres, descending in medial part of forearm between FDSsmaller ulnar head of pronator teres, descending in medial part of forearm between FDS and FDP muscles. Above wrist it is radial to FDS and directly beneath PL tendon. and FDP muscles. Above wrist it is radial to FDS and directly beneath PL tendon. Then it passes beneath transverse carpal ligament and after giving off motor Then it passes beneath transverse carpal ligament and after giving off motor branch to thenar muscle (OP, APB, superficial head of FPB) it inclines volarward to branch to thenar muscle (OP, APB, superficial head of FPB) it inclines volarward to supply by 6 terminal branches the thumb, index, middle and ring fingers. In hand it lies supply by 6 terminal branches the thumb, index, middle and ring fingers. In hand it lies in a plane superficial to tendons and deep to superficial vessels.in a plane superficial to tendons and deep to superficial vessels. First branches arising just above elbow are to humeral head of PT. Then below First branches arising just above elbow are to humeral head of PT. Then below elbow, branches supply rest of PT,FCR, PL and FDS. At upper border of PT a large elbow, branches supply rest of PT,FCR, PL and FDS. At upper border of PT a large interosseous branch arises, penetrates between the pronator heads and supplies radial interosseous branch arises, penetrates between the pronator heads and supplies radial portion of FDP and FPL, and then descends on the interosseous membrane along with portion of FDP and FPL, and then descends on the interosseous membrane along with AIA to end in PQ.AIA to end in PQ. In hand, it gives off 5 palmar digital nerves. First 3 supplies both sides of thumb In hand, it gives off 5 palmar digital nerves. First 3 supplies both sides of thumb and radial half of index finger. Each of other 2 divide at clefts distally to supply the and radial half of index finger. Each of other 2 divide at clefts distally to supply the opposing halves of index and middle fingers and middle and ring fingers. Motor and opposing halves of index and middle fingers and middle and ring fingers. Motor and sensory distribution of median and ulnar N frequently overlap. Normally median N sensory distribution of median and ulnar N frequently overlap. Normally median N supplies the palmar surface of thumb, index, middle and radial half of ring fingers and supplies the palmar surface of thumb, index, middle and radial half of ring fingers and dorsal surface of distal thirds of these fingers.dorsal surface of distal thirds of these fingers.

Median N-Clinical PictureMedian N-Clinical Picture Above elbow results in loss of flexion of thumb, index, and middle finger, wrist Above elbow results in loss of flexion of thumb, index, and middle finger, wrist flexion is weak and deviates ulnar side from unopposed action of FCU, pronation is flexion is weak and deviates ulnar side from unopposed action of FCU, pronation is weak or absent, thumb is in a position at the side of hand and cannot be brought into weak or absent, thumb is in a position at the side of hand and cannot be brought into

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opposition, upper forearm and thenar area are atrophied, loss of sensation in volar opposition, upper forearm and thenar area are atrophied, loss of sensation in volar aspect of thumb, index, middle and radial half of ring finger.aspect of thumb, index, middle and radial half of ring finger. Appearance of hand is similar to flat hand of monkey and is called simian hand. Appearance of hand is similar to flat hand of monkey and is called simian hand. Trophic changes occur at distal end of index finger, which becomes thin and conical. Trophic changes occur at distal end of index finger, which becomes thin and conical. Lesions at wrist occur from accidental cuts by knives or broken dishes or suicide Lesions at wrist occur from accidental cuts by knives or broken dishes or suicide attempts. It may be compressed against non yielding TCL by a dislocates lunate or by attempts. It may be compressed against non yielding TCL by a dislocates lunate or by strongly grasping an object particularly with wrist in flexion, whereby flexor tendons are strongly grasping an object particularly with wrist in flexion, whereby flexor tendons are strongly displaced volarly. strongly displaced volarly. Inflammatory synovial swelling due to RA or neoplasm encroaches on carpal Inflammatory synovial swelling due to RA or neoplasm encroaches on carpal tunnel and constricts the nerve. Lesions at carpal tunnel affects short abductors tunnel and constricts the nerve. Lesions at carpal tunnel affects short abductors (inability to abduct) opponens, superficial part of short flexors (FPB) and lumbricals to (inability to abduct) opponens, superficial part of short flexors (FPB) and lumbricals to index and middle fingers. Loss of sensation is same as in higher lesions.index and middle fingers. Loss of sensation is same as in higher lesions. Partial N injury or irritation is most common cause of causalgia. Severe burning Partial N injury or irritation is most common cause of causalgia. Severe burning pain in extremity and hand, aggravated by physical or emotional stimuli. Hand is initially pain in extremity and hand, aggravated by physical or emotional stimuli. Hand is initially swollen, red, warm, perspiring and hyper esthetic. Gradually skin becomes thinned, swollen, red, warm, perspiring and hyper esthetic. Gradually skin becomes thinned, glossy, cold, cyanotic and dry. The hand is held fixed with fingers extended and thumb glossy, cold, cyanotic and dry. The hand is held fixed with fingers extended and thumb adducted and joints may ankylose in this position. Pain becomes extremely distressing .adducted and joints may ankylose in this position. Pain becomes extremely distressing . Keeping the part moist seems to reduce the symptoms temporarily.Keeping the part moist seems to reduce the symptoms temporarily.

Median N-TreatmentMedian N-Treatment In nerve suture, better results are obtained from early intervention. Late repair In nerve suture, better results are obtained from early intervention. Late repair leads to partial restoration, particularly of sensation and paraesthesia. Nerve should be leads to partial restoration, particularly of sensation and paraesthesia. Nerve should be explored and ends obtained and sutured in exact rotary apposition. Gaps can be explored and ends obtained and sutured in exact rotary apposition. Gaps can be overcome in palm by flexing MCP joint. Above wrist the nerve is freed and wrist is overcome in palm by flexing MCP joint. Above wrist the nerve is freed and wrist is flexed. If elbow is also flexed and nerve is gently pulled distally, a 3 flexed. If elbow is also flexed and nerve is gently pulled distally, a 3 ½½ inch gap can be inch gap can be overcome.overcome. For larger gaps, dissect the nerve in upper arm and reroute it superficial to elbowFor larger gaps, dissect the nerve in upper arm and reroute it superficial to elbow structures by detaching humeral head of PT. A plaster cast maintains flexion of joints structures by detaching humeral head of PT. A plaster cast maintains flexion of joints and later very gradual extension is obtained over period of 1 month. If graft is needed, and later very gradual extension is obtained over period of 1 month. If graft is needed, Sural N may be used.Sural N may be used. At exploratory operation in causalgia states, nerve displays a lesion in continuity At exploratory operation in causalgia states, nerve displays a lesion in continuity (intraneural scarring). Complete division of nerve rarely causes causalgia. Treatment (intraneural scarring). Complete division of nerve rarely causes causalgia. Treatment consists of sympathectomy, preceded by procaine block of 2consists of sympathectomy, preceded by procaine block of 2ndnd thoracic ganglion. thoracic ganglion. Complete anhidrosis and increase in warmth of hand after 10 min of block. Pain is Complete anhidrosis and increase in warmth of hand after 10 min of block. Pain is relieved for 1 to 3 hours. A preganglionic sympathectomy is most effective. The white relieved for 1 to 3 hours. A preganglionic sympathectomy is most effective. The white rami communicates to 2rami communicates to 2ndnd and 3 and 3rdrd thoracic ganglia and sympathetic trunk below 3 thoracic ganglia and sympathetic trunk below 3rdrd are are divided.divided.

Radial N-AnatomyRadial N-Anatomy It is continuation of posterior cord formed by posterior divisions of brachial It is continuation of posterior cord formed by posterior divisions of brachial plexus. In axilla it lies directly behind Axillary A and runs on a floor formed by plexus. In axilla it lies directly behind Axillary A and runs on a floor formed by subscapularis muscle proximally and latissimus dorsi and teres major distally. Axillary subscapularis muscle proximally and latissimus dorsi and teres major distally. Axillary (circumflex) N which originates form posterior cord, descends alongside radial N, then (circumflex) N which originates form posterior cord, descends alongside radial N, then leaves it at lower border of subscapularis, where it passes backwards through leaves it at lower border of subscapularis, where it passes backwards through quadrangular space.quadrangular space.

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Beyond TM, it proceeds posterior to humerus by entering interval between long Beyond TM, it proceeds posterior to humerus by entering interval between long and medial heads of triceps and reaching spiral groove. It passes around back of and medial heads of triceps and reaching spiral groove. It passes around back of humerus to lateral side, where it pierces LIMS to reach anterior aspect of arm. Here it humerus to lateral side, where it pierces LIMS to reach anterior aspect of arm. Here it lies in interval between brachialis medially and brachioradialis and ECRL laterally.lies in interval between brachialis medially and brachioradialis and ECRL laterally. At this level it gives off branches to lateral half of brachialis, all of brachioradialis, At this level it gives off branches to lateral half of brachialis, all of brachioradialis, ECRL and PIN. It then continues distally in forearm under cover of BR till about 2ECRL and PIN. It then continues distally in forearm under cover of BR till about 2”” above wrist. It then pierces deep fascia and turns laterally and dorsally, crossing above wrist. It then pierces deep fascia and turns laterally and dorsally, crossing superficial to APL and EPB tendons and reaching dorsum of hand where it supplies superficial to APL and EPB tendons and reaching dorsum of hand where it supplies digital branches of sensation to dorsum of thumb, index, middle and ring finger as far asdigital branches of sensation to dorsum of thumb, index, middle and ring finger as far as MP.MP. In spiral groove radial N gives off posterior and lower lateral cutaneous nerves ofIn spiral groove radial N gives off posterior and lower lateral cutaneous nerves of arm, posterior cutaneous nerve of forearm, and muscular branches to triceps and arm, posterior cutaneous nerve of forearm, and muscular branches to triceps and anconeus. anconeus. PIN arises form radial N at level of lateral epicondyle. It descends under cover of PIN arises form radial N at level of lateral epicondyle. It descends under cover of BR and gives branches to ECRB and supinator. Then it penetrates supinator and BR and gives branches to ECRB and supinator. Then it penetrates supinator and passes obliquely around lateral aspect of shaft to reach back of forearm and travels passes obliquely around lateral aspect of shaft to reach back of forearm and travels distally of surface of APL under cover of EDL.distally of surface of APL under cover of EDL. Then it lies on IM under cover of EPL and proceeds distally to supply wrist joint. Then it lies on IM under cover of EPL and proceeds distally to supply wrist joint. In back of forearm it supplies remainder of extensor muscles and APL. Thus it supplies In back of forearm it supplies remainder of extensor muscles and APL. Thus it supplies all muscles on lateral and dorsal aspect of forearm except the BR and ECRL which are all muscles on lateral and dorsal aspect of forearm except the BR and ECRL which are supplied directly by radial N.supplied directly by radial N.

Radial N-Clinical PictureRadial N-Clinical Picture If radial N is interrupted at axilla where it is usually involved by direct If radial N is interrupted at axilla where it is usually involved by direct compression such as arm resting over back of chair (Saturday night palsy), the compression such as arm resting over back of chair (Saturday night palsy), the extensors of elbow, extensors and supinator of forearm, extensors of wrist, extensors ofextensors of elbow, extensors and supinator of forearm, extensors of wrist, extensors of MCP joints of fingers and extensor and long abductor of thumb are paralyzed. A strip of MCP joints of fingers and extensor and long abductor of thumb are paralyzed. A strip of posterior and posterolateral surface of arm, posterior third of forearm and autonomous posterior and posterolateral surface of arm, posterior third of forearm and autonomous zone on dorsum of hand over 1zone on dorsum of hand over 1stst IO web space are anesthetic. IO web space are anesthetic. Patient holds extremity at side, elbow is slightly flexed, forearm is pronated, handPatient holds extremity at side, elbow is slightly flexed, forearm is pronated, hand dropped at wrist and fingers are dropped at MCP joints. Thumb is turned forwards into dropped at wrist and fingers are dropped at MCP joints. Thumb is turned forwards into palm and interferes with flexion of fingers. Patient cannot make fist because wrist drop palm and interferes with flexion of fingers. Patient cannot make fist because wrist drop tenses the extensors of fingers and thereby opposes their flexion.tenses the extensors of fingers and thereby opposes their flexion. Involvement of nerve in spiral groove may be caused by sharp jagged edge of # Involvement of nerve in spiral groove may be caused by sharp jagged edge of # bone or may be delayed by callus formation and incarceration of nerve. Here it permits bone or may be delayed by callus formation and incarceration of nerve. Here it permits function of triceps and anconeus and preserves sensation at back of arm and forearm. function of triceps and anconeus and preserves sensation at back of arm and forearm. Injury to radial N between BR and brachialis involves BR and ECRL. But the Injury to radial N between BR and brachialis involves BR and ECRL. But the brachialis which has dual nerve supply may continue to function. brachialis which has dual nerve supply may continue to function. If injury is at level of radius where PIN encircles the bone 1 finger breadth below If injury is at level of radius where PIN encircles the bone 1 finger breadth below the head of radius, these muscles escape.the head of radius, these muscles escape. Beyond this level supinator brevis is permitted to function, whereas wrist drop, Beyond this level supinator brevis is permitted to function, whereas wrist drop, finger drop at MCP joints and thumb rolled forward into palm are the deformities.finger drop at MCP joints and thumb rolled forward into palm are the deformities. EPL, EPB & APL gain their branches of supply little more distally than EDC, EPL, EPB & APL gain their branches of supply little more distally than EDC, ECRL & ECRB so it is possible to have thumb alone involved by properly placed point ECRL & ECRB so it is possible to have thumb alone involved by properly placed point of trauma. When superficial radial N alone is severed, loss is restricted to sensation in of trauma. When superficial radial N alone is severed, loss is restricted to sensation in

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autonomous zone. This area is main site of pain when a causalgia state results form autonomous zone. This area is main site of pain when a causalgia state results form incomplete lesions of superficial radial. incomplete lesions of superficial radial. Partial paralysis of one or several muscles and hypoesthesia or Partial paralysis of one or several muscles and hypoesthesia or hyperesthesia rather than anesthesia indicate that the nerve lesion is incomplete hyperesthesia rather than anesthesia indicate that the nerve lesion is incomplete and continuity of the nerve is preserved. and continuity of the nerve is preserved. Examination of extension of fingers should be limited to MCP joints only as Examination of extension of fingers should be limited to MCP joints only as lumbricals supplied by median and ulnar nerves extend the IP joints.lumbricals supplied by median and ulnar nerves extend the IP joints. Automatic movements at wrist like extension due to finger flexion leading to Automatic movements at wrist like extension due to finger flexion leading to extensor tendon tightening should not be interpreted as preservation of movements.extensor tendon tightening should not be interpreted as preservation of movements.

Radial N - TreatmentRadial N - Treatment Regardless of level, affected muscles should be kept relaxed by supportive Regardless of level, affected muscles should be kept relaxed by supportive splints and their tone maintained by galvanic stimulation and light massage until nerve splints and their tone maintained by galvanic stimulation and light massage until nerve regenerates. Anterior moulded splint counteracts wrist drop and should extend beyond regenerates. Anterior moulded splint counteracts wrist drop and should extend beyond MCP joints to support PP. An additional extension from splint holds thumb in complete MCP joints to support PP. An additional extension from splint holds thumb in complete extension and dorsal abduction.extension and dorsal abduction. If paralysis is immediate and complete, nerve should be explored and sutured If paralysis is immediate and complete, nerve should be explored and sutured promptly. Good results are proportionate to early repair. Nothing is lost by early promptly. Good results are proportionate to early repair. Nothing is lost by early exploration and finding the nerve intact. exploration and finding the nerve intact. Gaps between nerve ends may be overcome by flexing the elbow, externally Gaps between nerve ends may be overcome by flexing the elbow, externally rotating and adducting the arm and by freeing various branches. If distance is extensive,rotating and adducting the arm and by freeing various branches. If distance is extensive, nerve may be transposed anteriorly. Shortening of humerus is sometimes justified to aidnerve may be transposed anteriorly. Shortening of humerus is sometimes justified to aid approximation.approximation. Compression injuries are generally temporary and almost complete restoration ofCompression injuries are generally temporary and almost complete restoration of function is the rule. function is the rule. Possibility of complete nerve tears and their serious implications certainly Possibility of complete nerve tears and their serious implications certainly warrant operative exposure of # site, whereupon both nerve and bone injuries can be warrant operative exposure of # site, whereupon both nerve and bone injuries can be dealt with at the same time.dealt with at the same time. Following complete cut of nerve, NCV begins to slow after 2-3 days and is Following complete cut of nerve, NCV begins to slow after 2-3 days and is maximum at 2 weeks. Therefore within 24-48 hours eliciting this findings justifies maximum at 2 weeks. Therefore within 24-48 hours eliciting this findings justifies surgical exploration. If no conduction impairment develops by 1 week, nerve interruptionsurgical exploration. If no conduction impairment develops by 1 week, nerve interruption is physiological (neuropraxia) and non surgical treatment is pursued. During this period is physiological (neuropraxia) and non surgical treatment is pursued. During this period electrical stimulation, heat and massage to maintain tone, splinting to relax affected electrical stimulation, heat and massage to maintain tone, splinting to relax affected muscles and range of motion exercises are started.muscles and range of motion exercises are started. When causalgia occurs, an incomplete nerve lesion should be suspected, the When causalgia occurs, an incomplete nerve lesion should be suspected, the nerve explored, neuroma if any should be resected, if necessary by removal of portion nerve explored, neuroma if any should be resected, if necessary by removal of portion of nerve, F/B re approximation, or adhesions if any are freed. of nerve, F/B re approximation, or adhesions if any are freed. The Tinel sign may reveal the exact site of initiation of pain impulses.The Tinel sign may reveal the exact site of initiation of pain impulses.

Radial N - PrognosisRadial N - Prognosis Prognosis of radial N repair is usually very good. Failure of some portion to Prognosis of radial N repair is usually very good. Failure of some portion to regenerate necessitates tendon transplantations.regenerate necessitates tendon transplantations. Triceps paralysis needs no compensation other than that provided by gravity. Triceps paralysis needs no compensation other than that provided by gravity.

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Supination of forearm may be restored by osteotomy of radius and by rotating Supination of forearm may be restored by osteotomy of radius and by rotating the distal fragment. Tubby operation transplants the insertion of PT from volar to dorsal the distal fragment. Tubby operation transplants the insertion of PT from volar to dorsal aspects of radius. aspects of radius.

Radial N - TreatmentRadial N - Treatment Extension and abduction of thumb which stabilizes the thumb at CMC joint is Extension and abduction of thumb which stabilizes the thumb at CMC joint is necessary for proper apposition. FCR may be transplanted to APL and EPL and EPB. necessary for proper apposition. FCR may be transplanted to APL and EPL and EPB. FCU is transferred to EDC. FCU is transferred to EDC. If no tendons are available, dorsiflexion of wrist is provided by arthrodesis of If no tendons are available, dorsiflexion of wrist is provided by arthrodesis of wrist or by cutting tendons of EDC and tenodesing the proximal ends of distal segment wrist or by cutting tendons of EDC and tenodesing the proximal ends of distal segment to dorsum of radius.to dorsum of radius. Active flexion at MCP joints thereby tightens these tenodesed tendons and Active flexion at MCP joints thereby tightens these tenodesed tendons and automatically dorsiflexes the wrist. The CMC joint of thumb may also be stabilized by automatically dorsiflexes the wrist. The CMC joint of thumb may also be stabilized by arthrodesis.arthrodesis.

Ulnar N - AnatomyUlnar N - Anatomy Largest branch of medial cord, arising under cover of PMn, and descending Largest branch of medial cord, arising under cover of PMn, and descending along medial side of Axillary A and proximal half of brachial A. At middle of humerus it along medial side of Axillary A and proximal half of brachial A. At middle of humerus it leaves brachial A and in company with UCA it passes backwards through the MIMS to leaves brachial A and in company with UCA it passes backwards through the MIMS to posterior aspect of arm. Then it descends along medial head of triceps to back of posterior aspect of arm. Then it descends along medial head of triceps to back of medial epicondyle and passes between heads of FCU to enter forearm. Under cover of medial epicondyle and passes between heads of FCU to enter forearm. Under cover of FCU (which it supplies) it lies on FDP (supplies its medial half) and is immediately FCU (which it supplies) it lies on FDP (supplies its medial half) and is immediately lateral to ulnar A.lateral to ulnar A. Near pisiform bone it emerges through deep fascia lateral to FCU and descends Near pisiform bone it emerges through deep fascia lateral to FCU and descends anterior to FR, where it divides into superficial and deep branches. Deep branch passesanterior to FR, where it divides into superficial and deep branches. Deep branch passes medial to hook of hamate and along with deep branch of ulnar A, enters interval medial to hook of hamate and along with deep branch of ulnar A, enters interval between ADM and FDM to gain the deep area of palm. It supplies to hypothenar between ADM and FDM to gain the deep area of palm. It supplies to hypothenar muscles and turns laterally across palm deep to flexor tendons giving off 3 branches, muscles and turns laterally across palm deep to flexor tendons giving off 3 branches, each of which runs distally in front of IS, supplying the interosseous muscles.each of which runs distally in front of IS, supplying the interosseous muscles. Medial 2 branches also medial 2 lumbricals muscles. At lateral side of palm, Medial 2 branches also medial 2 lumbricals muscles. At lateral side of palm, main deep branch of ulnar N ends by breaking up into nerves of supply to adductor main deep branch of ulnar N ends by breaking up into nerves of supply to adductor pollicis and 1pollicis and 1stst dorsal IM. Superficial branch of ulnar N runs under PB, which it supplies, dorsal IM. Superficial branch of ulnar N runs under PB, which it supplies, and then divides into 2 digital branches, which provide sensation to palmar aspect of and then divides into 2 digital branches, which provide sensation to palmar aspect of little and ulnar half of ring finger.little and ulnar half of ring finger. Dorsal branch arises at middle of forearm and descends with parent nerve to Dorsal branch arises at middle of forearm and descends with parent nerve to carpus, where it becomes superficial and inclines backwards to gain to dorsum of hand. carpus, where it becomes superficial and inclines backwards to gain to dorsum of hand. Here it divides into 2 dorsal digital nerves, which supply skin of medial third of back of Here it divides into 2 dorsal digital nerves, which supply skin of medial third of back of hand and little finger and ulnar half of ring finger as far as second phalanx.hand and little finger and ulnar half of ring finger as far as second phalanx.

Ulnar N Ulnar N –– Clinical picture Clinical picture If FCU is paralyzed, on attempting flexion at wrist, hand deviates radially, S/O If FCU is paralyzed, on attempting flexion at wrist, hand deviates radially, S/O interruption of ulnar N above elbow. interruption of ulnar N above elbow. Otherwise ulnar N paralysis leads to extension of ring and little fingers at MCP Otherwise ulnar N paralysis leads to extension of ring and little fingers at MCP joints and flexion at IP joints, because of lack of lumbricals. When lesion is sufficiently joints and flexion at IP joints, because of lack of lumbricals. When lesion is sufficiently

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low in forearm, FDP is spared and unopposed by intrinsic, exerts strong flexion on DP, low in forearm, FDP is spared and unopposed by intrinsic, exerts strong flexion on DP, clawing of ring and little fingers is pronounced.clawing of ring and little fingers is pronounced. When FCU and ulnar portion of FDP are paralyzed by a high lesion, atrophy overWhen FCU and ulnar portion of FDP are paralyzed by a high lesion, atrophy over ulnar aspect of forearm is very apparent. Flexion of DP of ring and little finger is lost. ulnar aspect of forearm is very apparent. Flexion of DP of ring and little finger is lost. Demonstrated best by placing hand palm down where inability of little finger to scratch Demonstrated best by placing hand palm down where inability of little finger to scratch the surface of table is evident.the surface of table is evident. Hypothenar eminence is thinned and hollowing of IS suggests atrophy of Hypothenar eminence is thinned and hollowing of IS suggests atrophy of interosseous. Abduction and adduction of fingers is lost to great extent. Index and interosseous. Abduction and adduction of fingers is lost to great extent. Index and middle finger may still abduct because their lumbricals innervations is through median middle finger may still abduct because their lumbricals innervations is through median N.N. Pinch between thumb and index finger normally depends on ability to stabilize Pinch between thumb and index finger normally depends on ability to stabilize MCP joint in flexion (adductors and flexor brevis) so that action is strong and apposed MCP joint in flexion (adductors and flexor brevis) so that action is strong and apposed fingers form letter O. in ulnar paralysis, PP is hyper extended, IP joint of thumb hyper fingers form letter O. in ulnar paralysis, PP is hyper extended, IP joint of thumb hyper flexes and pinch is weak. Failure of stabilization at CMC joint by APL will likewise flexes and pinch is weak. Failure of stabilization at CMC joint by APL will likewise interfere with pinch.interfere with pinch. Inability of thumb to scrape across distal palm suggests loss of thumb adductors.Inability of thumb to scrape across distal palm suggests loss of thumb adductors. Instead it comes forward into opposed position. Another test is failure to resist attempts Instead it comes forward into opposed position. Another test is failure to resist attempts to extract a sheet of paper held between apposed sides of thumb and index finger. to extract a sheet of paper held between apposed sides of thumb and index finger. Trophic changes in ring and little fingers reflect sensory loss. Very frequently Trophic changes in ring and little fingers reflect sensory loss. Very frequently innervations form median N preserves function of intrinsic and thumb adductors. Fibers innervations form median N preserves function of intrinsic and thumb adductors. Fibers innervating these muscles proceed distally in median N to distal 3innervating these muscles proceed distally in median N to distal 3rdrd of forearm and by a of forearm and by a connecting branch enter ulnar N. in such case a high ulnar lesion fails to eliminate connecting branch enter ulnar N. in such case a high ulnar lesion fails to eliminate intrinsic action.intrinsic action.

Ulnar N Ulnar N –– TreatmentTreatment Repair should be done with care. Nerve contains both motor and sensory fibers. Repair should be done with care. Nerve contains both motor and sensory fibers. Gaps are overcome by flexing wrist and elbow. Nerve at elbow may be transposed Gaps are overcome by flexing wrist and elbow. Nerve at elbow may be transposed anteriorly, and branches freed, permitting mobilization distally. Recovery of function anteriorly, and branches freed, permitting mobilization distally. Recovery of function requires > year in following order, forearm muscles, sensations, hypothenar muscles, requires > year in following order, forearm muscles, sensations, hypothenar muscles, interossei and thumb adductors.interossei and thumb adductors. During this period, hand is splinted with MCP joint in flexion and IP joint in During this period, hand is splinted with MCP joint in flexion and IP joint in extension to keep paralyzed muscles relaxed and prevent joint contractures. extension to keep paralyzed muscles relaxed and prevent joint contractures. When ulnar N paralysis is permanent, tendon transplantation is the treatment of When ulnar N paralysis is permanent, tendon transplantation is the treatment of choice.choice.

Ulnar N Ulnar N –– Repair of clawed fingersRepair of clawed fingers Claw hand is due to intrinsic muscle paralysis while long extensors and flexors Claw hand is due to intrinsic muscle paralysis while long extensors and flexors are still functioning. Loss of flexor power on PP allows extensors to pull PP into are still functioning. Loss of flexor power on PP allows extensors to pull PP into hyperextension, tension on long flexors pull DP into flexion, unopposed by lost hyperextension, tension on long flexors pull DP into flexion, unopposed by lost extension of intrinsic. extension of intrinsic.

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Extension of distal 2 phalanges takes place synergistically by long extensors andExtension of distal 2 phalanges takes place synergistically by long extensors and intrinsic. Action of long extensors is lost when PP is hyper extended. Any procedure thatintrinsic. Action of long extensors is lost when PP is hyper extended. Any procedure that prevents hyperextension of PP preserves extension of distal 2 phalanges and prevents hyperextension of PP preserves extension of distal 2 phalanges and eliminates claw deformity.eliminates claw deformity. Bunnell Technique : Transplants multiple slips of sublimis through lumbrical Bunnell Technique : Transplants multiple slips of sublimis through lumbrical canals into aponeurotic expansion. This procedure is not effective in claw hand of long canals into aponeurotic expansion. This procedure is not effective in claw hand of long standing in which patient has developed habit of flexing wrist to extend DP standing in which patient has developed habit of flexing wrist to extend DP automatically, thereby rendering the sublimis ineffective.automatically, thereby rendering the sublimis ineffective. Fowler Technique : Splits EIP and EDQ into 2 strands each, next each individual Fowler Technique : Splits EIP and EDQ into 2 strands each, next each individual slip is passed through IOS anterior to TMCL and inserted into aponeuroses.slip is passed through IOS anterior to TMCL and inserted into aponeuroses. Riordan technique : Tenodesis procedure. Half of ECRL & ECU is separated andRiordan technique : Tenodesis procedure. Half of ECRL & ECU is separated and each half is split longitudinally into 2 slips and then each slip is passed and attached each half is split longitudinally into 2 slips and then each slip is passed and attached into aponeuroses. Tendon should be under tension so as to obtain restriction of into aponeuroses. Tendon should be under tension so as to obtain restriction of extension.extension. Post operatively wrist is in dorsiflexion, MCP joints in flexion and distal 2 joints in Post operatively wrist is in dorsiflexion, MCP joints in flexion and distal 2 joints in extension.extension. Ulnar N Ulnar N –– Restoration of thumb adduction and archesRestoration of thumb adduction and arches When grasping small round objects, hand cups into arch and enables fingers to When grasping small round objects, hand cups into arch and enables fingers to converge during flexion, thus strength of grasp is obtained. These arches are produced converge during flexion, thus strength of grasp is obtained. These arches are produced mainly by thenar and hypothenar muscles. They are reduced considerably in ulnar mainly by thenar and hypothenar muscles. They are reduced considerably in ulnar paralysis and completely flattened in combined ulnar and median paralysis. It is paralysis and completely flattened in combined ulnar and median paralysis. It is essential to restore functions of pinch and grasp.essential to restore functions of pinch and grasp. Tendon Loop operation : EIP is removed just before its insertion and is Tendon Loop operation : EIP is removed just before its insertion and is prolonged by tendon graft around ulnar border of hand, placed volar to hypothenars andprolonged by tendon graft around ulnar border of hand, placed volar to hypothenars and beneath finger flexors and inserted into ulnar side of base of PP of thumb. The distal beneath finger flexors and inserted into ulnar side of base of PP of thumb. The distal remaining stump of tendon is attached to EI to avoid adduction and rotation deformity ofremaining stump of tendon is attached to EI to avoid adduction and rotation deformity of index finger. This procedure only adduction and is suitable only in pure ulnar paralysis.index finger. This procedure only adduction and is suitable only in pure ulnar paralysis. Tendon T Operation : Provides strong adduction to both thumb and index finger Tendon T Operation : Provides strong adduction to both thumb and index finger and reforms arches. Tendon graft is placed transversely across palm beneath flexor and reforms arches. Tendon graft is placed transversely across palm beneath flexor tendons and is attached to neck of 5tendons and is attached to neck of 5thth MC and ulnar side of base of PP of thumb. To its MC and ulnar side of base of PP of thumb. To its centre is attached motor tendon, usually one of sublimis. Contraction of motor tendon centre is attached motor tendon, usually one of sublimis. Contraction of motor tendon pulls on cross member and apposes thumb and index finger. This is more suitable whenpulls on cross member and apposes thumb and index finger. This is more suitable when median N is also involved with ulnar N and it becomes necessary to correct thumb median N is also involved with ulnar N and it becomes necessary to correct thumb opposition also.opposition also.

Compression of Ulnar N at elbowCompression of Ulnar N at elbow Also called traumatic ulnar neuritis, tardy ulnar N palsy and ulnar neuropathy at Also called traumatic ulnar neuritis, tardy ulnar N palsy and ulnar neuropathy at elbow. elbow. Chronic repetitive blunt trauma : Ulnar N is superficial within post condylar Chronic repetitive blunt trauma : Ulnar N is superficial within post condylar groove between olecrenon and medial epicondyle. Here it is vulnerable to single, severegroove between olecrenon and medial epicondyle. Here it is vulnerable to single, severe direct blow or to repeated external pressures, sustained under occupational conditions.direct blow or to repeated external pressures, sustained under occupational conditions. Post # : Nerve is held firmly within groove by firm dense fascia. Roughening of Post # : Nerve is held firmly within groove by firm dense fascia. Roughening of bone due to # imposes frictional force against gliding nerve.bone due to # imposes frictional force against gliding nerve.

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Cubitus Valgus deformity : Nerve is supposedly stretched over medial Cubitus Valgus deformity : Nerve is supposedly stretched over medial prominence at elbow. Deformity may be congenital and associated with anterior prominence at elbow. Deformity may be congenital and associated with anterior dislocation of radial head, retarded growth of lateral portion of lower humeral epiphyses dislocation of radial head, retarded growth of lateral portion of lower humeral epiphyses following trauma or infection, or mal union of #.following trauma or infection, or mal union of #. Arthritis of joint : OA produces irregularities of post condylar groove or may Arthritis of joint : OA produces irregularities of post condylar groove or may compress nerve by prominent osteophyte or protruding ganglion. Rheumatoid synoviumcompress nerve by prominent osteophyte or protruding ganglion. Rheumatoid synovium may penetrate the medial capsule and compress nerve.may penetrate the medial capsule and compress nerve. Recurrent subluxation or dislocation of nerve : When fascia covering nerve in Recurrent subluxation or dislocation of nerve : When fascia covering nerve in groove is thin and lax, ulnar N moves out of its groove onto tip of medial epicondyle groove is thin and lax, ulnar N moves out of its groove onto tip of medial epicondyle when elbow is completely flexed, returning to its normal location when elbow is when elbow is completely flexed, returning to its normal location when elbow is extended. Repetitive subluxation normally occurs in 16% of population. extended. Repetitive subluxation normally occurs in 16% of population. Acute trauma, infection : Produce scarring which can incarcerate ulnar N.Acute trauma, infection : Produce scarring which can incarcerate ulnar N. Muscle compression : By an accessory muscle, anconeus epitrochlearis, which Muscle compression : By an accessory muscle, anconeus epitrochlearis, which bridges the groove.bridges the groove. Idiopathic : Not unusual.Idiopathic : Not unusual.

PathophysiologyPathophysiology 2 cm distal to medial epicondyle, an aponeurotic arch passes between 2 heads 2 cm distal to medial epicondyle, an aponeurotic arch passes between 2 heads of origin of FCU, one firmly attached to medial epicondyle and other loosely attached to of origin of FCU, one firmly attached to medial epicondyle and other loosely attached to olecrenon, with aponeurotic arch forming roof of cubital tunnel. Floor of tunnel is formed olecrenon, with aponeurotic arch forming roof of cubital tunnel. Floor of tunnel is formed by medial capsule of elbow. During flexion, space of tunnel is diminished by tightening by medial capsule of elbow. During flexion, space of tunnel is diminished by tightening of aponeurotic arch and by outward bulging of capsule.of aponeurotic arch and by outward bulging of capsule. INP is 3 times when elbow is flexed with wrist extended; adding abduction and INP is 3 times when elbow is flexed with wrist extended; adding abduction and external rotation of arm as when placing hand behind head, INP is 6 times that of external rotation of arm as when placing hand behind head, INP is 6 times that of relaxed N, such pressures are capable of damaging nerves.relaxed N, such pressures are capable of damaging nerves. Aponeurotic arch, is slack in extension. When this is divided, underlying N is Aponeurotic arch, is slack in extension. When this is divided, underlying N is often found flattened, and proximally it presents a fusiform swelling.often found flattened, and proximally it presents a fusiform swelling. Normally, ulnar N elongates by 5 mm during flexion and glides freely in groove. Normally, ulnar N elongates by 5 mm during flexion and glides freely in groove. Encroachment on groove or cubital tunnel, produce friction, pressure and tension, whichEncroachment on groove or cubital tunnel, produce friction, pressure and tension, which compromises IN vascularity and results in edema and scarring.compromises IN vascularity and results in edema and scarring. Symptoms are highly variable, from subjective dysesthesias to combination of Symptoms are highly variable, from subjective dysesthesias to combination of sensory and motor deficit. FCU and ulnar half of FDP are usually spared. Reason is, sensory and motor deficit. FCU and ulnar half of FDP are usually spared. Reason is, fibers to these muscles are deeply situated in nerve at elbow and are generally fibers to these muscles are deeply situated in nerve at elbow and are generally unaffected by external compression.unaffected by external compression.

Clinical PictureClinical Picture H/O Cubitus valgus deformity, severe direct trauma or repetitive trauma to ulnar H/O Cubitus valgus deformity, severe direct trauma or repetitive trauma to ulnar groove.groove.

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Symptoms are related to severity of involvement. Minimal nerve irritation causes Symptoms are related to severity of involvement. Minimal nerve irritation causes subjective dysesthesias in ulnar distribution and sensation of clumsiness.subjective dysesthesias in ulnar distribution and sensation of clumsiness. Moderate involvement produces pronounced subjective pain and paraesthesia Moderate involvement produces pronounced subjective pain and paraesthesia and IO weakness and atrophy. FCU & FDP to DP of little and ring fingers are rarely and IO weakness and atrophy. FCU & FDP to DP of little and ring fingers are rarely affected. Nerve may be tender and palpably enlarged at post condylar groove.affected. Nerve may be tender and palpably enlarged at post condylar groove. Severe N lesions are rare. Interossei are very weak and atrophied. FCU & ulnar Severe N lesions are rare. Interossei are very weak and atrophied. FCU & ulnar half of FDP are partially weakened. Sensory loss varies from marked hypoesthesia to half of FDP are partially weakened. Sensory loss varies from marked hypoesthesia to anesthesia. Sweating in reduced, although hyperhydrosis is not infrequent.anesthesia. Sweating in reduced, although hyperhydrosis is not infrequent. Cubital tunnel syndrome caused by compression of N by arcuate ligament is Cubital tunnel syndrome caused by compression of N by arcuate ligament is provoked by prolonged flexion attitudes of elbow, such as during sleep. Sometimes provoked by prolonged flexion attitudes of elbow, such as during sleep. Sometimes symptoms can be elicited by acutely flexing elbow for about 5 minutes (elbow flexion symptoms can be elicited by acutely flexing elbow for about 5 minutes (elbow flexion test).test). Recurrent ulnar N subluxation at elbow are usually asymptomatic, unless traumaRecurrent ulnar N subluxation at elbow are usually asymptomatic, unless trauma is superimposed. Complete anterior displacement is exceptional. Condition is nearly is superimposed. Complete anterior displacement is exceptional. Condition is nearly always bilateral. Enlarged tender N can be felt to slip beneath examining finger during always bilateral. Enlarged tender N can be felt to slip beneath examining finger during flexion and extension.flexion and extension.

DiagnosisDiagnosis Traumatic ulnar neuritis at elbow must be differentiated from ulnar N Traumatic ulnar neuritis at elbow must be differentiated from ulnar N compression at wrist. Dorsal cutaneous branch of ulnar N leaves parent N beyond compression at wrist. Dorsal cutaneous branch of ulnar N leaves parent N beyond elbow. So sensory impairment in dorsal ulnar aspect of hand localizes lesion proximally.elbow. So sensory impairment in dorsal ulnar aspect of hand localizes lesion proximally. Contrariwise, absence of this finding does not necessarily implicate ulnar N lesion at Contrariwise, absence of this finding does not necessarily implicate ulnar N lesion at wrist, because N may be only partially involved at elbow.wrist, because N may be only partially involved at elbow. Electro diagnostic studies will reveal slowing of conduction at elbow, and Electro diagnostic studies will reveal slowing of conduction at elbow, and differentiate whether N is involved proximally (at thoracic outlet) or distally at wrist. differentiate whether N is involved proximally (at thoracic outlet) or distally at wrist. Preoperatively it is important to determine compressive bone lesion about ulnar groove. Preoperatively it is important to determine compressive bone lesion about ulnar groove. In addition to routine x-rays, special view is taken to outline groove. The externally In addition to routine x-rays, special view is taken to outline groove. The externally rotated arm is placed against cassette, while elbow is acutely flexed, and central x-ray rotated arm is placed against cassette, while elbow is acutely flexed, and central x-ray beam is directed vertically.beam is directed vertically.

PrognosisPrognosis Depends largely on degree of N involvement and time interval between onset of Depends largely on degree of N involvement and time interval between onset of symptoms and surgical intervention. In minimal involvement, anterior transposition of N symptoms and surgical intervention. In minimal involvement, anterior transposition of N leads to immediate relief of local discomfort and peripheral paraesthesia. With moderateleads to immediate relief of local discomfort and peripheral paraesthesia. With moderate sensory and motor impairment, following surgery, hand becomes stronger, but variable sensory and motor impairment, following surgery, hand becomes stronger, but variable weakness and sensory impairment persist in some. In advanced paralysis, surgery weakness and sensory impairment persist in some. In advanced paralysis, surgery results in partial recovery of motor power in some but sensory recovery is better, normalresults in partial recovery of motor power in some but sensory recovery is better, normal function is never regained.function is never regained. After 1 year, only about 1/4After 1 year, only about 1/4thth of patients will achieve satisfactory recovery after of patients will achieve satisfactory recovery after anterior transposition and improvement after simple aponeurotic release is poor. anterior transposition and improvement after simple aponeurotic release is poor. Muscle power continue to improve over 6 months to year. Long flexor muscles Muscle power continue to improve over 6 months to year. Long flexor muscles recover more completely than intrinsic. Variable sensory deficit often persists. Completerecover more completely than intrinsic. Variable sensory deficit often persists. Complete

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recovery is rarely attained if course exceeds 3 months and chances are poor when recovery is rarely attained if course exceeds 3 months and chances are poor when symptoms have existed for 1 year. symptoms have existed for 1 year.

TreatmentTreatment Nerve must be transposed anteriorly. Sites of potential kinking should receive Nerve must be transposed anteriorly. Sites of potential kinking should receive proper attention. MIMS extending proximally from epicondyle must be adequately proper attention. MIMS extending proximally from epicondyle must be adequately resected. Aponeurotic band is released. N should not be laid in groove cut in muscle, resected. Aponeurotic band is released. N should not be laid in groove cut in muscle, because scarring and IMS become adherent to N. Origin of common flexor pronator because scarring and IMS become adherent to N. Origin of common flexor pronator tendon should be elevated, the N placed beneath the muscle mass, and tendon origin tendon should be elevated, the N placed beneath the muscle mass, and tendon origin restored. Occasionally, it may be possible to remove local compressing lesion like restored. Occasionally, it may be possible to remove local compressing lesion like ganglion or osteophyte without need for anterior transposition.ganglion or osteophyte without need for anterior transposition.

Ulnar N compression at wristUlnar N compression at wrist Ulnar N courses through tunnel anterior to FR just lateral to pisiform, then dividesUlnar N courses through tunnel anterior to FR just lateral to pisiform, then divides into superficial (mainly sensory) and deep branch as it proceeds distally. Floor of narrowinto superficial (mainly sensory) and deep branch as it proceeds distally. Floor of narrow canal is formed by ligaments between pisiform, triquetrum and hamate. Because of canal is formed by ligaments between pisiform, triquetrum and hamate. Because of limited diameter, it is vulnerable to lesions that encroach on canal (OA osteophyte, limited diameter, it is vulnerable to lesions that encroach on canal (OA osteophyte, ganglion, rheumatoid pannus). When N is compressed proximal to point of bifurcation, ganglion, rheumatoid pannus). When N is compressed proximal to point of bifurcation, both sensory and intrinsic muscle deficit results. both sensory and intrinsic muscle deficit results. As dorsal branch leaves ulnar N proximal to wrist, sensation to medial third of As dorsal branch leaves ulnar N proximal to wrist, sensation to medial third of back of hand and entire dorsal surface of little and ulnar half of ring finger as far as MP back of hand and entire dorsal surface of little and ulnar half of ring finger as far as MP is preserved. When N compression is within tunnel distal to bifurcation, only deep is preserved. When N compression is within tunnel distal to bifurcation, only deep branch is affected, hypothenars are often spared, and intrinsic muscles denervated. branch is affected, hypothenars are often spared, and intrinsic muscles denervated. FDP to little and ring fingers and FCU is unaffected. FDP to little and ring fingers and FCU is unaffected.

Ulnar N compression at wrist-AnatomyUlnar N compression at wrist-Anatomy Ulnar A and N enter hand through triangular space (GuyonUlnar A and N enter hand through triangular space (Guyon’’s canal), which is s canal), which is bordered medially and proximally by FCU and pisiform, anteriorly by thin VCL blended bordered medially and proximally by FCU and pisiform, anteriorly by thin VCL blended with tendinous insertion of FCU and posteriorly by TCL overlying pisotriquetral joint. with tendinous insertion of FCU and posteriorly by TCL overlying pisotriquetral joint. Distal to GuyonDistal to Guyon’’s canal, under cover of PB muscle, nerve divides into superficial and s canal, under cover of PB muscle, nerve divides into superficial and deep branches. deep branches. Superficial branch supplies overlying muscle and passes through fat pad, Superficial branch supplies overlying muscle and passes through fat pad, courses distally and SC to provide sensory innervations to ulnar side of palm.courses distally and SC to provide sensory innervations to ulnar side of palm. Deep branch passes lateral to pisiform, then medial to hook of hamate, where it Deep branch passes lateral to pisiform, then medial to hook of hamate, where it makes an abrupt turn as it dips between origins of ADM & FDM. It enters narrow fibro-makes an abrupt turn as it dips between origins of ADM & FDM. It enters narrow fibro-osseous tunnel that is bounded proximally by pisohamate ligament.osseous tunnel that is bounded proximally by pisohamate ligament. Before it passes into this extremely narrow tunnel, deep palmar branch supplies Before it passes into this extremely narrow tunnel, deep palmar branch supplies motor N to hypothenar muscles; then passes through opponens and turns laterally motor N to hypothenar muscles; then passes through opponens and turns laterally under cover of deep flexor tendons along line of deep palmar arch and supplies under cover of deep flexor tendons along line of deep palmar arch and supplies branches to interossei, 3branches to interossei, 3rdrd & 4 & 4thth lumbricals, adductor pollicis and deep part of FPB. As lumbricals, adductor pollicis and deep part of FPB. As deep branch passes across palm, it lies in close relationship to proximal end of MC, deep branch passes across palm, it lies in close relationship to proximal end of MC, providing hard surface against which nerve may be compressed.providing hard surface against which nerve may be compressed. Within GuyonWithin Guyon’’s canal, ulnar N lies medially and ulnar A lies laterally, and s canal, ulnar N lies medially and ulnar A lies laterally, and remainder of space is occupied by fat globules. Beyond narrow rigid fibro-osseous canalremainder of space is occupied by fat globules. Beyond narrow rigid fibro-osseous canal as nerve courses deep in palm, nerve is most often damaged by penetrating injury.as nerve courses deep in palm, nerve is most often damaged by penetrating injury.

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Motor fibers are posterior and sensory fibers are anterior. Theoretically, if N is Motor fibers are posterior and sensory fibers are anterior. Theoretically, if N is compressed posteriorly, motor weakness should prevail over sensory loss. However, compressed posteriorly, motor weakness should prevail over sensory loss. However, this is not the clinical situation, because both motor and sensory deficits develop this is not the clinical situation, because both motor and sensory deficits develop concomitantly. Because dorsal cutaneous branch leaves main N 6 to 8 cm proximal to concomitantly. Because dorsal cutaneous branch leaves main N 6 to 8 cm proximal to wrist, an injury beyond this level spares the dorsal ulnar distribution.wrist, an injury beyond this level spares the dorsal ulnar distribution.

PathologyPathology Ganglion produce largest number of compressive lesions at wrist.Ganglion produce largest number of compressive lesions at wrist. Often H/O blunt trauma over hypothenar area by single severe blow from using Often H/O blunt trauma over hypothenar area by single severe blow from using hand as hammer or by fall on outstretched hand or repetitive trauma. Pisiform appear tohand as hammer or by fall on outstretched hand or repetitive trauma. Pisiform appear to sustain the brunt of injury, and OA changes develop at pisotriquetral joint.sustain the brunt of injury, and OA changes develop at pisotriquetral joint.

Scarring may develop weeks to months after an injury about hypothenar Scarring may develop weeks to months after an injury about hypothenar eminence, enveloping both ulnar N and ulnar A within Guyoneminence, enveloping both ulnar N and ulnar A within Guyon’’s canal. At surgery, s canal. At surgery, edematous fibrous tissue and thrombosed vessels are found. They appear to constrict edematous fibrous tissue and thrombosed vessels are found. They appear to constrict the nerve, and provided that collateral circulation is adequate, resection of scar tissue the nerve, and provided that collateral circulation is adequate, resection of scar tissue and affected segment of ulnar A and freeing the nerve will relieve neurological and affected segment of ulnar A and freeing the nerve will relieve neurological symptoms.symptoms. Ulnar A because of superficial location is vulnerable to injury. Single or repetitive Ulnar A because of superficial location is vulnerable to injury. Single or repetitive blunt trauma may damage intimae, resulting in thrombosis. Trauma also disrupts elastic blunt trauma may damage intimae, resulting in thrombosis. Trauma also disrupts elastic fibers resulting in progressively enlarging true aneurysm, or penetrating injury may fibers resulting in progressively enlarging true aneurysm, or penetrating injury may partially tear A, producing localized hemorrhagic mass whose interior becomes partially tear A, producing localized hemorrhagic mass whose interior becomes reanalyzed, developing a cystic, bulbous false aneurysm. Regardless of cause, ulnar reanalyzed, developing a cystic, bulbous false aneurysm. Regardless of cause, ulnar neuritis occurs, and majority of cases produce paraesthesia and objective sensory loss. neuritis occurs, and majority of cases produce paraesthesia and objective sensory loss.

Clinical PictureClinical Picture Dependant on site and degree of injury. Dependant on site and degree of injury. 2 anatomical patterns; lesion proximal to pisohamate ligament that causes both 2 anatomical patterns; lesion proximal to pisohamate ligament that causes both sensory and motor involvement and lesion deep in palm distal to pisohamate ligament sensory and motor involvement and lesion deep in palm distal to pisohamate ligament that affects interossei and ulnar lumbricals but spares hypothenar muscles and ulnar that affects interossei and ulnar lumbricals but spares hypothenar muscles and ulnar volar sensations.volar sensations. Compression at level of GuyonCompression at level of Guyon’’s canal presents following features :-s canal presents following features :- Compressive tissue (ganglion, RA pannus, bone fragment) is sometimes Compressive tissue (ganglion, RA pannus, bone fragment) is sometimes palpable. palpable. Sensory loss over volar ulnar distribution but spares dorsal area except over DP.Sensory loss over volar ulnar distribution but spares dorsal area except over DP. Motor involvement affects hypothenar, ulnar 2 lumbricals and interossei.Motor involvement affects hypothenar, ulnar 2 lumbricals and interossei. Clawing of little and ring fingers.Clawing of little and ring fingers. Compressive lesions that exerts pressure only on deep branch produces purely Compressive lesions that exerts pressure only on deep branch produces purely motor weakness of interossei but spares hypothenar muscles. Abducted attitude of little motor weakness of interossei but spares hypothenar muscles. Abducted attitude of little finger results from unopposed action of ADM. Clawing of little and ring finger is seen finger results from unopposed action of ADM. Clawing of little and ring finger is seen sometimes. In general development and effects take place silently i.e. without pain.sometimes. In general development and effects take place silently i.e. without pain.

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Penetrating injury within palm leads to involvement of motor structures beyond Penetrating injury within palm leads to involvement of motor structures beyond the point of nerve interruption. the point of nerve interruption. OA of pisotriquetral joint causes pain and tenderness over pisiform, crepts and OA of pisotriquetral joint causes pain and tenderness over pisiform, crepts and pain elicited by passively moving pisiform bone from side to side. Active ulnar deviation pain elicited by passively moving pisiform bone from side to side. Active ulnar deviation and flexion of wrist against resistance reproduce pain.and flexion of wrist against resistance reproduce pain. Rarely, superficial branch may sustain direct injury, leading to pain over ulnar Rarely, superficial branch may sustain direct injury, leading to pain over ulnar side of palm and ring and little fingers, where sensory loss may be detected with no side of palm and ring and little fingers, where sensory loss may be detected with no sensory loss over proximal portion of dorsal aspect of these fingers. sensory loss over proximal portion of dorsal aspect of these fingers. Positive TinelPositive Tinel’’s sign.s sign. X-ray evidence of bone fragment.X-ray evidence of bone fragment. Intrinsic muscles are not affected.Intrinsic muscles are not affected.

DiagnosisDiagnosis Muscle weakness and wasting are seen but is common to whole lot of Muscle weakness and wasting are seen but is common to whole lot of neurological and myopathic conditions. neurological and myopathic conditions. When symptoms suggest distal ulnar N involvement, inquire about injury such asWhen symptoms suggest distal ulnar N involvement, inquire about injury such as laceration, despite a time lapse. laceration, despite a time lapse. Detailed sensory examination to distinguish between nerve compression at Detailed sensory examination to distinguish between nerve compression at elbow from injury to distal portion. When sensation is lost over volar ulnar area, but elbow from injury to distal portion. When sensation is lost over volar ulnar area, but intact over dorsal ulnar area, injury is localized distal to point of origin of dorsal sensory intact over dorsal ulnar area, injury is localized distal to point of origin of dorsal sensory branch (6 to 8 cm above wrist).branch (6 to 8 cm above wrist). Muscle examination must be detailed.Muscle examination must be detailed. EMG studies of 1EMG studies of 1stst dorsal interossei may show fibrillation potentials S/O dorsal interossei may show fibrillation potentials S/O involvement of deep branch.involvement of deep branch. NCV studies between wrist and 1NCV studies between wrist and 1stst DI or adductor pollicis, is highly diagnostic DI or adductor pollicis, is highly diagnostic and any delay must be clearly demonstrated before surgical intervention. When and any delay must be clearly demonstrated before surgical intervention. When fibrillation potentials are already present on EMG studies, denervation is far advanced.fibrillation potentials are already present on EMG studies, denervation is far advanced. X-rays of wrist and hand, including special carpal tunnel and pisiform views are X-rays of wrist and hand, including special carpal tunnel and pisiform views are necessary to determine presence of OA, # and neoplasm.necessary to determine presence of OA, # and neoplasm.

TreatmentTreatment Immediate decompression of ulnar N is mandatory. Nerve is isolated adjacent to Immediate decompression of ulnar N is mandatory. Nerve is isolated adjacent to FCU tendon in distal forearm and then freed progressively by cutting volar carpal FCU tendon in distal forearm and then freed progressively by cutting volar carpal ligament and then fascial roof overlying interval between pisiform and hook of hamate. ligament and then fascial roof overlying interval between pisiform and hook of hamate. Any compressive lesion is identified and removed. When OA of pisotriquetral joint is Any compressive lesion is identified and removed. When OA of pisotriquetral joint is present or pisiform is dislocated, bone may be removed without impairing power of wristpresent or pisiform is dislocated, bone may be removed without impairing power of wrist flexion.flexion. When possibility of severance of deep palmar branch by penetrating injury When possibility of severance of deep palmar branch by penetrating injury exists, nerve should be explored beneath the flexor tendons in palm and repair carried exists, nerve should be explored beneath the flexor tendons in palm and repair carried out. Thrombotic occlusion of ulnar A at wrist requires segmental arterial resection. out. Thrombotic occlusion of ulnar A at wrist requires segmental arterial resection. Aneurysm of A requires excision of aneurysmal sac. If collateral circulation is Aneurysm of A requires excision of aneurysmal sac. If collateral circulation is insufficient, restoration of arterial continuity by end to end anastomosis or a vein graft is insufficient, restoration of arterial continuity by end to end anastomosis or a vein graft is necessary.necessary.

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