ĐẶT VẤN ĐỀ 1 INTRODUCTION Peripheral nerve injury in which the upper extremity nerve damage has dangerous or milder complications, leaving health damaging sequelae, greatly affecting the patient''''s qua[.]
1 INTRODUCTION Peripheral nerve injury in which the upper extremity nerve damage has dangerous or milder complications, leaving health-damaging sequelae, greatly affecting the patient's quality of life and work, causing serious damages economically harmful to individuals, families and society Nerve injury in the forearm segment usually consists of a single or combined lesion of the ulnar nerves, medial and radial One of the common causes of nerve injury in the forearm segment is trauma and injury in criminal cases Around the world, many authors have researched on peripheral nerve injury such as Kouyoumdjian JA (1999-2004), Zhang XY (2011), Castillo Galván ML (2008 - 2012) Most of the research results indicate the injury The upper extremity nerve accounts for the majority (> 60%), in which the ulnar nerve is injured alone or in combination with other nerves accounting for the most proportion In Vietnam, no author has studied peripheral nerve injury in subjects for forensic examination of injuries, using an adjuvant test of peripheral nerve electrophysiology We conducted the topic titled: Study on nerve injury in the forearm segment in the subject of injury assessment, with the two objectives: Describing the clinical characteristics, electrophysiological method for peripheral nerve in the group of injury assessment subjects with nerve injury in the forearm segment Assessing the relationship between some clinical characteristics and the electrophysiological method for peripheral nerve index of the study subjects New contributions of the thesis Scientific and valuable contributions of the thesis: Detailed and comprehensive description of clinical characteristics, electrophysiological method for peripheral nerve conduction index of victim with nerve injury in the forearm segment (ulnar nerve, median nerve and radial) nerve) The study showed that the conduction velocity of the nerve helps to diagnose the localization of the ulnar nerve, medial, radial lesions When examining the electromyogram, seeing spontaneous voltages or muscle fiber twitches helps in early diagnosis of complete or incomplete damage Research evaluating the recovery of nerve damage After months by electromyography is more valuable than conduction measurement The left lesion is related to the radial nerve lesion There is a relationship between the injured hand (left hand) and neuromuscular re-innervation The severity of the disease according to the Quick DASH score was only associated with radial nerve damage (myelin and axonal damage) and neuromuscular rewiring 2 The Thesis layout The layout of the thesis: The thesis consists of 121 pages of main content Introduction: pages; Chapter I: Literature Overview: 33 pages; Chapter II: Research Subjects and Methods: 20 pages; Chapter III: Research results: 33 pages; Chapter IV: Discussion: 30 pages; Conclusion: pages; Recommendation: page The thesis has 48 tables, 19 figures, charts, 116 references including 28 documents in Vietnamese, 88 documents in English CHAPTER - LITERATURE OVERVIEW 1.1 Basic characteristics of peripheral nerve injury 1.1.1 Neuroanatomical features of the upper forearm - Radial nerve: divided into branches, superficial branch and deep branch (posterior interosseous nerve) The superficial branch that descends posteriorly to the rotator cuff muscle provides sensation to the lateral dorsum of the hand The deep branch goes between the two layers of the back muscles and then radiates many branches between the two muscle layers of the posterior forearm to control movement for these muscles The posterior interosseous nerve innervates all muscles of the posterior forearm, except the radial radial muscle and the long radial wrist extensor, which is innervated by the lateral branches of the radial nerve - Ulnar nerve: In the upper part of the wrist, the ulnar nerve gives the ulnar carpal flexor motor branch and the inner half of the Flexor Digitorum Profundus (fingers IV and V) The ulnar nerve enters the hand and divides into two branches: the superficial branch and the deep branch The superficial branch supplies sensation to fingers V and ½ of the fourth toe and to the short palmar motor branch The deep branch moves the remaining muscles of the mammary gland, goes around the hook bone and goes deep into the hand, moving all the remaining muscles of the palm; minus muscles controlled by the median nerve: Abductor pollicis brevis muscle, Flexor Pollicis Brevis, Opponens pollicis and Lumbricales 1, - Median nerve: The median nerve crosses the ulnar artery in the upper third of the forearm, working all of the anterior forearm muscles, except the ulnar flexor carpal and the medial half of the Flexor Digitorum Profundus The motor branch for the quadriceps muscle is called the anterior interosseous nerve Median nerve in the hand supplies sensation to fingers I, II, III, outside the fourth finger of the palm and moves muscles: Abductor pollicis brevis muscle, Flexor Pollicis Brevis, Opponens pollicis and Lumbricales 1.1.2 Injury-causing object Non-sharp objects in forensic science are solid, hard (iron) or semi- rigid (hands, rubber sticks) objects that not have sharp blades and pointed tips at the place of impact with the body; Injury caused by non-sharp objects is created by the interaction between the body and non-sharp objects, in many different ways: impact, compression, friction, twisting non-sharp objects are more difficult to join and not very efficient Sharp objects are hard objects with sharp blades or edges, with or without a pointed tip; sharp objects have various shapes and sizes: knives, swords, glass shards, metal pieces ; The wound caused by sharp objects is formed by the impact of the sharp blade and sharp edge with the mechanism of pressing, pulling and pushing along its longitudinal axis In case of nerve breakage, it is easier to suture with higher efficiency 1.1.3 Classification of Peripheral nerve injury 1.1.3.1 Classification of SEDDON: divided into levels: - Loss of nervous practicality: Nerves only lose their conduction function Conduction function will recover after weeks or months - Axonal rupture: In the cord, some nerve fibers are severed or bruised Full neurological recovery will take longer - Nerve rupture: is an injury that causes complete or incomplete rupture of a nerve and its associated organization No self-healing 1.1.3.2 Classification of SUNDERLAND: divided into levels: Level 1: Loss of axon conduction Level 2: Discontinuous axonal loss, all capsule intact Level 3: Only axonal and interstitial nerve sheaths are involved, the nerve fiber bundle and the nerve bundle are intact Level 4: Injury to both axons, nerve sheath, nerve fiber bundle, and intact nerve bundle Level 5: Complete detachment of nerve 1.1.4 Clinical peripheral nerve injury * Ulnar nerve paralysis - Motor: Limit folding of the hand into the forearm Loss of flexion and extension of fingers The matching movement between the thumb and the ring finger is also difficult Limiting the flexion of the ring, little, and 1st vertebrae as well as the 2nd and 3rd vertebrae that cannot be performed, the 3rd flexion is affected while the 2nd flexion is still possible The hand is in the stroked position - Sensory: Decrease or loss of sensation in: palmar surface: little finger, inner half of ring finger, and palmar from the axis of the ring finger inward; dorsal surface of the hand: little finger, first and second middle knuckles of the ring finger, middle half of the first middle and back of the hand from the axis of the middle finger inward - Nutritional disorders: Muscle atrophy or bluish-purple skin on the little and ring fingers, redness on the inside of the hand, thin and edematous skin - Reflex: Loss of Réflexe cubito pronateur * Median nerve paralysis - Motor: Forearm pronation cannot be performed Limit hand flexion Unable to flex thumb and index finger When holding hands, there is a special shape “preaching hand” Thumbs can't finger counting Unable to fold and contrast the thumb Hand is shaped “monkey hand” - Sensory: Decrease or loss of sensation in: lateral part of palmar from the axis of the ring finger, excluding the lateral margin of the macular cell; liver surface of the thumb, index, middle and outer half of the ring finger; dorsal surface of the 2nd, 3rd and third index fingers, middle and outer half of the ring finger - Nutritional disorders: Muscle atrophy may be accompanied by cyanosis and dry skin in the fingers, especially in the 2-3 knuckles of the index and middle fingers * Radial nerve - Motor: Inability to stretch forearms, hands, and fingers The sign of the hand with the stork neck It is not possible to extend and extend the hand at the same time, difficult to close the hand However, the movement of opening and closing the hand can still be performed to a certain extent The hand cannot be turned upside down Flexion of the weakened forearm Weak thumb shape - Sensory: Decrease or loss of sensation of privacy in the hand: dorsal side of the thumb, first knuckle of the index finger, and the outer half of the first middle finger; Loss of sensation on the back of the forearm and the lateral half of the hand from the axis of the middle finger upward - Nutritional disorders: Discreet, edema on the back of the hand, muscle atrophy - Reflex: Loss of brachial triceps tendon reflex and rotator cuff reflex 1.1.5 Assessment of clinical injury Use the Quick DASH Scale to assess clinical severity Accordingly, 11 questions are divided into groups, each group has its own clinical assessment according to levels Victim answered questions based on their actual activities during the previous week Each activity will be given a score from to depending on the difficulty or limitation of doing that activity Divided into levels: Mild: 11-22 points Moderate: 23 - 33 points Severity: 34 - 55 points 1.2 Electrophysiological Method for peripheral nerve in the diagnosis of peripheral nerve injury 1.2.1 Measuring the conduction of ulnar nerve, median nerve and radial nerve 1.2.1.1 Measuring Motor conduction velocity The parameters recorded when investigating motor conduction include: peripheral locomotor time (DML), Motor conduction velocity (MCV), amplitude and duration of the total muscle action potential 1.2.1.2 Measuring Sensory conduction velocity Parameters recorded when investigating sensory conduction include: sensory latency time (DSL), Sensory conduction velocity (SCV), amplitude of sensory nerve action potential 1.2.2 Electromyography 1.2.2.1 Recording method Parameters recorded during electromyography: - Potential due to needle insertion: When the potential due to needle insertion is reduced, we consider there is evidence of a decrease in the number of healthy muscle fibers - Spontaneous voltage: reflects the neurodistribution in the subacute or chronic phase of neuropathy Based on the abnormality of muscle groups can help determine the location of nerve damage - Voltage of motor unit: high amplitude, wide interval, multiphase - Image of aggregation: phenomenon of late aggregation, incomplete interference or no interference 1.2.2.2 Muscle groups that electromyography + Muscles innervated by the ulnar nerve: ulnar wrist flexor, anterior ulnar muscle, deep flexor, thumb adductor, dorsal I interosseous muscle, little finger + Muscles innervated by the median nerve: superficial flexor flexor, deep flexor, thumb contralateral muscle, pronation round, and proximal square + Muscles innervated by the radial nerve: long supine muscle, common extensor finger, rotator cuff extensor, long thumb extensor, index finger separate extensor CHAPTER - RESEARCH SUBJECTS AND METHODS 2.1 Research subjects 2.1.1 Selection criteria - The victim came for injury assessment at the Institute of Criminal Science Victim with trauma, forearm injuries have peripheral nerve injury (ulnar nerve, median nerve and radial nerve); had surgery or not Clinical examination and complete Electrophysiological Method for peripheral nerve - Volunteer to participate in research and have good coordination ability 2.1.2 Exclusion criteria - History of other neurological damage not due to trauma: cerebral palsy (in children), after stroke (in adults), brain tumor - Lack of clinical and laboratory data for diagnosis - Duration of injury more than year 2.2 Research Methods 2.2.1 Research design Cross-sectional descriptive study 2.2.2 Sample size and selection of sample for research Convenient sample size, taking the entire sample during the study period, obtained 100 people who met the criteria 2.2.3 Research mediums - Nicolet Electrophysiology Machine (NIHON KOHDEN Model MEB-9400K), according to the method of Delisa et al (1994) - Research medical record: meticulously designed, including full content to evaluate the patient comprehensively 2.2.4 The method of data collection Victim will be asked directly by the researcher, have a comprehensive clinical examination, assess the degree of clinical damage to the upper extremities according to the Quick DASH scale, and perform tests according to the medical record with the aim of collecting data for recovery research service A cross-sectional descriptive study at two time points (at first assessment and After months), through the second time, victim were clinically re-evaluated and electrophysiological method for peripheral nerve to compare and evaluate the relationship between some clinical characteristics and the electrophysiological method for peripheral nerve index of study subjects between two different time points Nerve conduction study: collecting parameters including: time of peripheral motor potential (prolonged), amplitude of motor action potential and Motor conduction velocity (decreased or lost); sensory latency (prolonged), amplitude of sensory neuronal action potentials, and Sensory conduction velocity (decreased or lost) Investigation of needle electrodes: collecting parameters including: needle insertion potential, spontaneous potential, motor unit potential and aggregation image of each surveyed location Victim who complete the above steps will be selected to participate in the study Since then, we have studied the clinical and subclinical characteristics and evaluated the relationship between some clinical features and some nerve conduction indices, electromyography CHAPTER - RESEARCH RESULTS 3.1 General characteristics of the study subjects Table 3.1 General characteristics of the study subjects (n=100) Characteristics n Rate (%) Male 80 80% Gender Female 20 20% Minors ( < < > 0,05 0,05 19,9 ± 19,4 ± 0,05 45,84 ± 44,73 ± 0,05 < 18 1,8 ± 2,2 1,7 ± 2,2 2,9 ± 2,6 2,8 ± 2,9 26,9 26,3 38,36 37,21 10,6 ± 37,4 ± 36 ± Female 9,6 ± 21,4 23,7 34,15 32,95 > < 29,8 ± 29,2 ± 0,05 48,35 ± 47,35 ± 0,05 Male 28,6 28,2 33,73 32,81 64 ± 16,66 ± 16,33 ± < 1th 0 65 ± 3,46 0 3,46 1,52 3,78 28,6 ± 27,76 ± > 43,32 ± 42,44 ± > 2,68 ± 2,44 ± < 9,96 ± 8,84 ± > 1-6th 28,4 27,79 0,05 32,25 31,49 0,05 3,15 3,05 0,05 9,93 10,01 0,05 34,8 ± 34,8 ± 52,6 ± 50,6 ± 13,8 ± 12,8 ± th >6 4,4 ± 1,1 ± 0,7 31,7 31,7 48,6 46,75 14,2 14,6 39,3 ± 38,5 ± 42,08 ± 40,58 ± 4,16 ± 4,16 ± 8,58 ± 6,58 ± Right 29,4 29,1 39,87 38,39 > 2,79 2,72 11,59 11,11 < < > 19,8 ± 19,3 ± 0,05 49,33 ± 48,52 ± 0,05 1,85 ± 1,71 ± 0,05 12,61 ± 12,14 ± 0,05 Left 26 25,4 30,01 29,38 2,78 2,72 9,35 9,73 15 Table 3.15 Relationship between disease severity according to Quick DASH and some CLS indexes Conduction velocity of ulnar nerve Conduction Amplitude of ulnar nerve Motor p Sensory p Motor p Sensory p Initial After Initial After After Initial After Initial time time months time months months time months 5,9 ± 5,45 ± 5,81 ± 5,63 ± 0,81 ± 2,71 0,72 ± 0,72 ± 0,63 ± Mild 19,59 18,09 19,29 18,69 2,41 2,41 2,11 14,5 ± 14,08 ± > 1,5 ± 3,06 1,41 ± > 0 Disease Medium 0 > 0,05 > 0,05 21,72 20,9 0,05 2,5 0,05 level 5,35 ± 7,69 ± 1,13 ± 0,49 ± 1,5 0,77 ± 0,18 ± 0,16 ± Serious 1,26 ± 9,2 16,19 17,5 8,24 1,62 1,37 1,23 Table 3.16 Relationship between disease severity according to Quick DASH and some CLS indexes Conduction velocity of median nerve Conduction Amplitude of median nerve Motor p Sensory p Motor p Sensory p After Initial After Initial After Initial After Initial month time months time months time months time s Mild 0 0 0 0 0 > 0 > 0 > 0 > Disease Medium level 10,57 ± 10,57 ± 0,05 10,3 ± 10,24 ± 0,05 0,75 ± 0,6 ± 0,05 1,84 ± 1,6 ± 0,05 Serious 22,78 22,8 20,56 20,37 1,69 1,49 3,84 3,3 16 Table 3.17 Relationship between disease severity according to Quick DASH and some CLS indexes Conduction velocity of radial nerve Motor p Sensory p Initial After Initial After time months time months 56,33 ± 54,33 ± 65 ± 62,66 ± Mild 3,78 3,78 56,34 54,3 < 13,9 ± 13 ± 40,95 ± 40,13 ± > Disease Medium 0,0 23,26 21,75 28,96 28,46 0,05 level 51,75 ± 52,37 ± 55,62 ± 54,37 ± Serious 21,96 22,09 36,98 35,68 Conduction Amplitude of radial nerve Motor p Sensory p Initial After Initial After time months time months 5,33 ± 5,33 ± 8± 4,33 ± 1,52 1,52 6,92 3,78 > 1,54 ± 1,45 ± < 10,5 ± 9,4 ± 0,0 2,32 2,4 0,01 8,48 8,4 4,87 ± 4,75 ± 14,12 ± 14,25 ± 3,27 2,96 15,28 15,71 Table 3.18 Comparison of the degree of clinical damage (evaluated by the Quick DASH scale) in the group with neuromuscular loss at the time of assessment and with neuromuscular reintroduction After months (n=39) Quick DASH Score Group with loss of neuromuscular control at the time of assessment Group with loss of neuromuscular control at the time of assessment and with neuromuscular re-innervation After months Mean value Standard deviation 38,58 7,75 38,56 7,72 P 0,3 17 Table 3.19 Comparison of the degree of clinical damage (as assessed by the Quick DASH scale) in the group with neuromuscular loss at the time of assessment and without neuromuscular control After months (n=51) Quick DASH Score Mean value Standard deviation Group with loss of neuromuscular control at the time of assessment The group with neuromuscular loss at the time of assessment and no neuromuscular re-difference After months 33,39 1,27 33,33 1,26 P 0,08 Table 3.20 Relationship between disease severity according to Quick DASH and neuromuscular rewiring (Pearson) Mild Medium Serious Neuromuscular re-innervation (%) 2,56 20,52 76,92 p < 0,01 18 CHAPTER - DISCUSSION 4.1 Clinical characteristics, electrophysiological method for peripheral nerve in the subject of injury assessment had nerve injury in the forearm segment 4.1.1 Clinical features In our study, 80% of the study subjects were men, the ratio Male/Female = 4/1 The mean age is 32.9 years old (standard deviation 11.9), in which the youngest person is years old, the oldest is 65 years old The high proportion of men and the relatively young average age is due to the fact that the subjects with neurological damage are mostly in the collisions with the main participants being men, young age, not thinking yet mature, not able to keep calm, easily excitable, friction, collision, fight leading to injuries with serious and very serious consequences The rate in the study is also quite similar to the study of author Kouyoumdjian when the average age was 32.4 years old, the percentage of men was 74% and the author Miranda had an average age of 33.6 years old, the proportion of men was 74.7% In our study, 88% of the subjects were in the adolescent age group, 12% of the victim were in the juvenile age group The age ratio in the study is also similar to the results of author Zhang XY and colleagues when people aged ≤ 19 accounted for 8.9%, people aged > 19 accounted for 91.1%; author Castillo - Galván ML and associates with adolescent victim (≤ 18 years old) accounted for 19%, adolescent victim (> 18 years old) accounted for 81% The grouping of research subjects by occupation comes from the fact that the context of forearm nerve injuries is strongly related to the specificity of each occupational group In the process of working, there are objective and subjective factors that lead to conflicts from small to large, from arguing to fighting, causing injury The group of mental workers who mainly work with their brains, not with their muscles (cadres, civil servants and public employees) such as doctors, teachers, office workers, etc., this group has low sample risk hand and foot collision The group of self-employed workers who mainly work with their hands and feet, using muscles more than their brains include: farmers, drivers, freelancers, housewives, builders, porters this group there is a lot of risk of conflict of hand and foot collision In this study, 84% of the subjects were self-employed, only 16% of the subjects were mental workers The high rate of self-employed workers is partly due to the fact that the division of groups in society is already high, but it is undeniable that manual workers often have low incomes, they have to take care of their lives living, living simply, resigned, acting somewhat instinctively, so it is easy to get into conflicts, conflicts, then spontaneous actions can cause serious consequences, especially injuries, The wound leaves sequelae of nerve damage The study of Zhang XY and colleagues also has a similar distribution of occupations in the self-employed group of 82.9%, the group of intellectual workers is 17.1% The hand that was injured in the study was mainly the forearm and was more affected in the left hand (59%) This can be explained, in the process of collision, the 19 person being hit often uses both hands to block and counter the opponent's blow, in the two hands, the non-dominant hand usually reflexively moves forward the opponent, the dominant hand is usually in a defensive position to block or respond to the opponent later, so the non-dominant hand is more vulnerable than the dominant hand; Besides, the majority of non-dominant hands are left-handed, so the rate of injured left hand is higher than that of right hand Moreover, when using the hand to support, the forearm is most often injured Author JA Kouyoumdjian and colleagues also have the results through a retrospective survey on 1124 cases that found common nerve injuries in the forearm and wrist due to more exposure to injury-causing objects The frequency of injury to the nerves in the forearm in the study showed that the most common injury was in the ulnar nerve (76%), much less than the other nerves, with 36% in the median nerve and 30% in the radial nerve, shows that it is appropriate for many situations where the victim is directly attacked by an opponent while raising his arm for protection, where the back of the forearm is the most vulnerable to the impact and in terms of facial features Anatomically, the ulnar nerve is closest to the medial back of the forearm compared to the median nerve and rotates, making it more susceptible to injury In addition, the ulnar nerve is often injured alone and in combination with other nerves, in the case of combined damage, it usually damages ulnar nerve and median nerve (85.7%) because they are close to each other as in anatomy The results are similar to those in the study of the world's authors: JA Kouyoumdjian et al; LR Robinson; I Maclean et al found that the ulnar nerve is most commonly involved and when combined, it is often associated with the median nerve The detailed study of the location of the nerves in the forearm showed that the damage was mainly in the upper third (40%) and the lower 1/3 of the forearm (41%) The middle third of the forearm is uncommon (19%), possibly due to the reflex swinging the arm in many positions when having an accident or fighting so injuries are common at both ends (distal end, proximal end) of the forearm, Anatomically the proximal part (elbow and wrist joint) is the more mobile site in contact with the object causing more injury Similar to the results of author JA Kouyoumdjian et al., described common nerve lesions in the elbow and wrist region Evaluation of the most common lesions of the ulnar nerve, median nerve and radial nerve in the upper forearm segment clinically by each nerve showed that radial nerve damage was most common in the upper third of the forearm (48.5 %), in the lower third of the forearm, ulnar nerve (47.4%) and median nerve (52.8%) Injury to multiple nerves is also common in the lower third of the forearm with the ratio of nerves combined is 57.2% and nerves combined is 60% In this study, victim with ulnar nerve, middle, and radial lesions had relatively clear clinical symptoms and high sensitivity because most of the nerve damage was axonal damage The results reflect correctly for cases of nerve damage, regardless of the nerve, all victim have sensory disturbances (100%) with reduced, 20 loss of sensation or numbness, pain in the area controlled by the corresponding nerve; Basic clinical symptoms of movement such as restriction of flexion, extension, flexion, extension, adduction, rotation, pronation, supine, etc., were evident in all victim (88.9 - 100%), however expressed in varying degrees different degrees; In addition, the typical clinical manifestations of injury to each ulnar nerve, medial, and radial nerve are not as many as the patient with the hand in the "claw" position in the ulnar nerve lesion only 5.3%, the disease Victim with hands in “monkey hand” shape in median nerve lesions only 5.5%, victim with “drooping position” hands in radial nerve lesions only 6.1% This is easy to explain because in the study, the victim mainly came to the clinic not too late (the time to visit was months before with the rate of 71%), so the clinical manifestations of sensation and movement were very clear, while The typical clinical picture often appears when long-term complications are in the later stages Another reason is that the time to clinical examination is related to the statute of limitations for injury assessment, that is, after an injury, the patient is always interested in the health status and severity of the situation by the police investigation injuries, are taken to the doctor for assessment as soon as possible to serve the investigation and trial, so late clinical manifestations are less common Clinical severity (forearm function) will be assessed using the Quick DASH scale The study showed that the average score of the Quick DASH Scale was 34.7 ± 9.1 points, the patient's Quick DASH score in the study was the lowest 16, the highest score was 48 Evaluation of the results, showed: The group of victim with severe clinical lesions accounted for the majority (56%), the moderate and mild group less, 30% and 14% respectively Research results of other authors such as Toshihiko Imaeda have an average score of Quick DASH scale of 28 points The difference in mean score may be due to Toshihiko Imaeda's study on 72 victim, 02 victim did not respond to any item, 01 patient did not respond to item 5, the remaining patient did not respond to item 7, only 55 out of 72 (76%) victim responded fully The mechanism of injury formation in injury-related injury assessments is very diverse, caused by many types of impact objects, mutual collisions in many situations Regarding injury-causing objects, the research is divided into two groups: sharp objects and non-sharp objects The study showed that most of the victim in the study had nerve damage caused by sharp objects (knife, sword, glass shards, metal shards) (94%); only 6% are caused by non-sharp objects (sticks, cones, falls, bumps) similar to the study by authors Zhang XY et al., KlineDG, Yurdal Gezercan et al In the study of Zhang XY and colleagues with 72 cases of nerve injury, up to 68 cases were caused by the impact of sharp objects (94.4%), only cases were caused by the impact of non-sharp objects (5.6%) When evaluating the group of objects according to the injured nerves in the forearm, sharp objects are the main cause of all nerves, in which the median nerve group is the most (100%), followed by the ulnar nerve group and rotation are ... people aged ≤ 19 accounted for 8.9%, people aged > 19 accounted for 91.1%; author Castillo - Galván ML and associates with adolescent victim (≤ 18 years old) accounted for 19%, adolescent victim