Hand Injury

　　Hand injuries include piercing, sharp instrument injury, blunt trauma, crush injury, and firearm injury, and their specific causes are described as follows.

　　1. Piercing Injury

　　Injuries caused by nails, needles, bamboo tips, wood splinters, small glass fragments, etc. The characteristics are small entry points, deep injuries, which can damage deep tissues, and can also bring foreign matter into deep tissues, leading to foreign body retention and tenosynovitis or deep tissue infection.

　　2. Sharp Instrument Injury

　　Cuts from knives, glass, cans, and other objects in daily life, and cutting injuries from paper cutters and electric saws during work generally have整齐 wounds, light contamination, abundant bleeding, and varying depths of wounds, resulting in different degrees of tissue damage. Commonly cause important deep tissue injuries such as nerve, tendon, and vascular lacerations, and in severe cases, finger tip defects, finger amputation, or limb amputation.

　　3. Blunt Trauma

　　Blunt trauma can cause tissue contusion, leading to skin lacerations, and in severe cases, skin avulsion, tendon, nerve injury, and fractures. Blunt trauma from heavy objects can cause severe damage to various tissues of the finger or whole hand; high-speed rotating blades, such as engine and electric fan blades, often cause amputation and finger amputation.

　　4. Crush Injury

　　Window and door crushing can only cause finger tip injuries, such as finger hematoma, nail bed rupture, and distal phalanx fracture; while wheel and machine roller crushing can cause extensive skin avulsion and even anterior hand skin avulsion injury, multiple open fractures, joint dislocation, and severe destruction of deep tissues. In some cases, finger and whole-hand destructive injuries may require amputation (digit).

　　5. Firearm Injury

　　Injuries caused by firecrackers, detonator explosions, and high-speed shrapnel, especially explosive injuries, have extremely irregular wounds. The range of injury is extensive, often resulting in large areas of skin and soft tissue defects, as well as multiple comminuted fractures. This type of injury is severely contaminated, with a high incidence of necrotic toes and prone to infection.

　　Patients with hand injuries who do not pay attention to early exercise after surgery may develop tendinous and joint adhesions, resulting in dysfunction, and in severe cases, can cause joint stiffness and traumatic arthritis. In addition, the most common complication of open hand injuries is infection, mainly due to severe tissue crush caused by mechanical entanglement, compression injuries, unclear distinction of viable and non-viable tissues, incomplete debridement, etc.

　　Hand injuries are divided into open injuries and closed injuries, and their specific clinical manifestations are described as follows.

　　1. Open Injuries:Such injuries often occur with bleeding, pain, swelling, deformity, and (or) dysfunction.

　　2. Closed Injuries:Closed injuries, due to the integrity of the skin, and the subcutaneous tissue is severely swollen after injury, which is easy to cause circulatory disorders, and some patients may even cause necrosis of distal limbs or soft tissues due to this.

　　Hand injuries are divided into puncture wounds, cutting wounds, blunt instrument injuries, door and window squeezing injuries, and firearm injuries. The prevention of this disease mainly focuses on the prevention of etiology. In daily life, it is necessary to avoid trauma and actively treat injuries once they occur. If the injury is severe, surgery should be performed as soon as possible.

　　Hand injuries involving nerve, muscle, and blood vessel injuries require corresponding relevant examinations. Sometimes, patients with amputation reimplantation need to test prothrombin time, fibrinogen, and other tests. For those affecting the overall condition, perform blood biochemical tests and blood gas analysis, etc.

　　First, Examination of Skin Injuries

　　1. Understanding the Location and Nature of the Wound:Based on the local anatomical relationship, preliminarily speculate the possibility of injury to various important tissues under the skin, such as tendons, nerves, and blood vessels.

　　2. Estimation of Skin Defects:Whether there is a defect in the skin of the wound, the size of the defect, whether it can be directly sutured, and whether direct suture will affect the healing of the wound.

　　3. Judgment of Skin Vitality:The nature of the injury is an important factor affecting the vitality of the injured skin. Cutting injuries have good vitality at the skin edges and are easy to heal; crushing injuries can cause extensive skin avulsion; skin stripping injuries have a complete skin surface, but the skin and the underlying tissue are in a subcutaneous separation, the blood circulation between the skin and its base is interrupted, which seriously affects the survival of the skin and should be highly valued. The following methods can help judge the vitality of the skin.

　　(1) Color and Temperature of Skin If it is consistent with the surrounding area, the skin vitality is normal; if the local injury is pale, blue, and cold, it indicates poor vitality.

　　(2) Capillary Return Test If the skin turns white when pressing the skin surface and quickly returns to red after releasing the finger, it indicates good vitality; if the skin recovers slowly or not at all, it indicates poor or no vitality.

　　(3) Shape and Size of Skin Flaps Lingual skin flaps and double pedicle bridge flaps have good vitality. The distal part of lobulated or polygonal flaps often has poor vitality, and the tip part is prone to necrosis after suture.

　　(4) Ratio of Length to Width of Skin Flaps In addition to the damaged part that is torn off, the blood supply from the pedicle of the peeled skin flap may also be damaged to varying degrees. Therefore, the length-to-width ratio of the skin flap that can survive is smaller than that of the normal skin flap obtained during skin harvesting. This should be determined according to the condition of the skin injury. It cannot be decided according to the conventional length-to-width ratio whether to keep or remove the damaged skin.

　　(5) Direction of the skin flap Generally speaking, the vitality of the pedicle is better when it is located at the proximal end of the limb than when it is located at the distal end.

　　(6) Condition of skin edge bleeding During the trimming of the skin edges, there may be spots of bright red blood, which then slowly flows out, indicating good skin vitality. If the skin edges do not bleed or dark purple blood flows out, the vitality is poor.

　　Two, Examination of Tendon Injuries

　　Tendon rupture changes the resting position of the hand. When the flexor tendon is ruptured, the straightening angle of the finger increases. When the extensor tendon is ruptured, the bending angle of the finger increases, and the active flexion or extension function of the finger is lost, and some typical deformities may appear, such as the rupture of the deep and superficial flexor tendons, and the finger being in a straightened state. The rupture of the extensor tendon on the dorsal side of the metacarpophalangeal joint causes the joint to be in a flexed position. The injury to the extensor tendon on the dorsal side of the proximal phalanx causes the proximal interphalangeal joint to be in a flexed position, and the injury to the extensor tendon on the dorsal side of the middle phalanx causes the distal phalanx to be屈曲 in a hammer toe deformity. It should be noted that when multiple tendons participate in the function of the same joint, the injury of one tendon may not show obvious dysfunction.

　　The examination method for flexor tendons is to fix the middle phalanx of the injured finger, allowing the patient to actively flex the distal interphalangeal joint. If it cannot be flexed, it indicates a deep flexor tendon injury. Fix the other three fingers except the one being examined, and allow the patient to actively flex the proximal interphalangeal joint. If it cannot be flexed, it indicates a superficial flexor tendon rupture. When both the deep and superficial flexor tendons are ruptured, the two interphalangeal joints of the finger cannot be flexed. To check the function of the flexor pollicis longus tendon, fix the proximal phalanx of the thumb and allow the patient to actively flex the interphalangeal joint, which means that the lumbrical and interosseous muscles have the function of flexing the metacarpophalangeal joint of the fingers. The rupture of the flexor tendons does not affect the flexion of the metacarpophalangeal joint and should be noted.

　　Three, Examination of Nerve Injuries

　　The motor and sensory functions of the hand are controlled by the median nerve, ulnar nerve, and radial nerve, which are composed of roots from the brachial plexus. The muscles involved in wrist and finger flexion and extension, as well as their nerve branches, are located in the proximal forearm. Nerve injuries caused by hand trauma mainly manifest as sensory dysfunction and dysfunction of the intrinsic hand muscles. The main manifestations include paralysis of the abductor pollicis brevis muscle due to median nerve paralysis, leading to dysfunction of thumb opposition and pinching between thumb and index finger. There are sensory disturbances on the palmar side of the hand, including the radial side of the thumb, index, middle, and ring fingers, and the radial side of the middle phalanx of the thumb and the proximal interphalangeal joints of the index, middle, and ring fingers. The ulnar nerve paralysis causes claw-like deformities of the ring and small fingers due to interosseous and lumbrical muscle paralysis. The Froment sign, caused by the paralysis of the interosseous and adductor pollicis muscles, is characterized by marked flexion of the proximal interphalangeal joint of the index finger, hyperextension of the distal interphalangeal joint, and hyperextension of the metacarpophalangeal joint of the thumb, as well as finger joint flexion, and sensory disturbances on the ulnar side of the hand, the radial side of the ring finger, and the palmar side of the small finger. The radial nerve, which has no motor branches below the wrist, only presents with sensory disturbances on the radial side of the back of the hand and the proximal interphalangeal joints of the three and a half radial fingers.

　　Four, the examination of vascular injuries

　　To understand whether there is any injury to the main blood vessels of the hand, the nature and degree of the injury, the condition of the hand blood circulation, and the blood vessel injury can be judged by the color, temperature of the fingers, capillary reflux test, and blood pulsation. Paleness of the skin, reduced skin temperature, indentation of the finger pulp, slow or disappearance of capillary reflux, and weak arterial pulsation indicate arterial injury. Blue and purple skin, swelling, rapid capillary reflux, and good arterial pulsation indicate venous return obstruction.

　　The hand has abundant blood supply and multiple collateral circulation, mainly supplied by the ulnar artery and radial artery. The ulnar and radial arteries communicate with each other through the superficial palmar arch and deep palmar arch in the palm. When the two arterial arches of the palm are intact, the single injury of the ulnar and radial arteries rarely causes obstruction of the hand blood circulation. The Allen test can check whether the ulnar and radial arteries are unobstructed and the anastomosis between them. The specific method is: let the patient clench their fists and drive the blood in the hand to the forearm, the examiner uses both thumbs to press the distal ulnar and radial arteries of the forearm to prevent blood flow, and then let the patient extend their fingers. At this time, the hand becomes pale and ischemic, and then release the pressure on the ulnar artery, allowing blood flow through, and the whole hand turns red rapidly. Repeat the above test. If the hand remains pale after releasing the pressure on the ulnar or radial artery, it indicates that the artery is ruptured or embolized.

　　Five, the examination of bone and joint injuries

　　For those with local pain, swelling, and dysfunction, suspected bone and joint injuries may be present. If there is significant shortening of the fingers, rotation, angular or lateral deviation deformity, and abnormal movement, it can be diagnosed as a fracture. For all suspected fractures, X-rays should be taken to understand the type and displacement of the fracture, prepare for treatment, and therefore, X-ray examination should be listed as a routine examination for hand injuries. In addition to taking anteroposterior and lateral X-rays, especially when the metacarpal bones overlap in the lateral view, oblique views should be added.

　　When checking the function of the wrist joint and finger joints, the fully extended joint is considered 0 degrees. There are individual differences in the range of motion of each joint, and there are no precise statistical figures. When checking, attention should be paid to the comparison of both sides. Normally, the wrist joint can flex 50 to 60 degrees, extend 50 to 0 degrees, radial deviation 25 to 30 degrees, and ulnar deviation 30 to 40 degrees. The comparison of the range of motion of the two wrist joints can be observed by pressing the palms together to extend the wrist and pressing the backs of the hands together to flex the wrist, respectively, to see the differences in the flexion and extension range of the wrist joints on both sides.

　　The屈伸 range of the thumb's掌指 joint is large, up to 90 degrees, usually 30 to 40 degrees. The thumb's shoulder joint is 80 to 90 degrees. The thumb's abduction is when the thumb extends parallel to the palm, and the abduction to the index finger's proximal radial side is 0 degrees. The thumb's opposition is when the palmar aspect of the thumb and the palmar aspect of the little finger are opposed to each other as the standard.

　　The掌指关节 of the finger should be屈曲80 to 90 degrees, overextension 0 to 20 degrees, the proximal interphalangeal joint屈曲90 to 100 degrees, and extend 0 degrees. The original interphalangeal joint屈曲70 to 90 degrees, and extend 0 degrees. The fingers take the middle finger as the center, and the movement range of abduction and adduction is 30 to 40 degrees.

　　Hand injury patients should eat high-protein, high-sugar, collagen-rich, trace elements (copper, zinc, iron, calcium) and vitamin (A, C) rich foods such as lean meat, pork skin, liver, egg yolk, dairy products, carrots, fresh vegetables and fruits, etc., to supplement sufficient nutrition, which can promote wound healing and body recovery.

　　Four things should not be eaten in the diet of hand injury patients

　　1. Seafood and other 'inducing' foods should not be eaten:Such as seafood, goose meat, rooster, donkey meat, horse meat, pork, pork head meat, and leeks, etc.

　　2. Spicy foods should not be eaten:Such as chili, scallion, garlic, etc.

　　3. Foods high in fat should not be eaten:Such as fatty meat, fried food, oil-fried food, butter, cheese, etc.

　　4. Foods that should not be eaten due to their heat-promoting properties:Such as mutton, deer meat, dog meat, cinnamon, white wine, etc.

　　Hand injuries are divided into open and closed injuries, and the specific treatment methods are described as follows.

　　First Aid Measures

　　1. Open Wounds

　　(1) First Aid Principles

　　It must be handled in a timely manner. Generally, open wounds should strive to close the wound within 6 to 8 hours after the injury to greatly reduce the occurrence of postoperative infection.

　　(2) First Aid Methods

　　When an open hand injury occurs, it should be sent to the nearest hospital for treatment in a timely manner, and the routine injection of tetanus antitoxin should be given.

　　During the transportation to the hospital, if there is severe bleeding, local compression can be applied, or a belt or elastic band can be used to tie around the upper arm to stop the bleeding. However, if this method is used for止血, it is important to loosen the belt or elastic band for 10 to 15 minutes every hour or so, otherwise it may lead to the necrosis of the entire limb.

　　If the injury results in a fracture of the limb, it is best to perform a simple fixation before transportation, using materials such as wood planks, iron rods, or hard books and magazines, in order to avoid secondary injury to the surrounding soft tissues such as nerves, blood vessels, and tendons during transportation.

　　If there is a limb or finger amputation injury, it is best to wrap the amputated limb or finger in a plastic bag and place it in a low-temperature保温桶for preservation, and send it to the hospital with the patient, never freeze the residual limb or place it directly in ice water.

　　2. Closed injuries

　　First aid principles: In closed injuries, it is also necessary to seek medical attention in a timely manner, so that the doctor can make a comprehensive and accurate judgment of the condition, so as not to delay early treatment. If the patient feels that the limb is obviously swollen, there are pale or blue hands, numb fingers, disappearance of radial artery pulsation, and other conditions, it is necessary to seek medical attention promptly and deal with it in time.

　　Second, disease treatment

　　1. Early injury assessment

　　Since the structure of the hand is very delicate and complex, it is very important to accurately judge the condition after injury. In hand injuries, the skin is often the first tissue to be affected, followed by muscles, tendons, nerves, blood vessels, and bones and joints.

　　(1) Judgment of skin injuries:Skin damage is very直观, but the prognosis of different types of skin damage is different. Sharp object cuts are relatively easy to deal with. Hair comb injuries or large areas of skin stripping or damage are very difficult to handle. Since hair comb injuries cut the skin into strips, it is almost impossible to suture and repair it well. Large areas of skin stripping injuries are often difficult to determine whether the stripped skin still has blood supply, and whether it will necrose after replantation. Sharp object cuts should not be taken lightly either. If the wound is caused by a knife that cuts meat, due to the contamination of the wound with exogenous proteins such as meat juice, the wound is very prone to infection and non-healing. The same situation may also occur in wounds caused by human or animal bites.

　　(2) Judgment of nerve injuries:If there is a decrease, disappearance, and/or impairment of movement at the distal part of the injury site, it is highly suspected that the nerve may have been injured. At this time, it is not enough to go to a general hospital for debridement and suture. It is necessary to visit a hand surgery specialist to strive for early repair of nerve injuries to achieve the best possible efficacy.

　　(3) Judgment of vascular injuries:In open injuries, bleeding is inevitable. However, if there is喷射性出血 from the wound, it may indicate that an artery has been injured, and it is necessary to apply pressure to stop the bleeding immediately, or apply a tourniquet at the proximal end of the wound. Otherwise, the patient may quickly go into shock due to blood loss, even threatening life. In addition, if the distal part of the wound is pale, pulseless, and the skin temperature is significantly reduced, it often indicates that the blood supply to that area is extremely poor. Without吻合血管 and reconstructing blood circulation, the limb cannot be preserved. At this time, the patient should be sent directly to a hospital with a hand surgery specialist for treatment to avoid delaying treatment due to repeated transfers.

　　(4) Judgment of muscle and tendon injuries:If there is a functional impairment of one or more fingers without sensory减退, it may be due to tendon or muscle injury, and it is necessary to find a hand surgery specialist for repair at this time.

　　(5) Judgment of bone and joint injuries:If there are deformities, abnormal movements, or local obvious swelling and tenderness in the bones and joints, it often indicates the possibility of bone and joint injuries. At this time, it is necessary to take X-rays to determine the severity of the injury. When taking X-rays of the hand, attention should be paid not to take only the anteroposterior and oblique views of the whole hand, but to take anteroposterior, lateral, and oblique views of a specific finger or joint. This is to avoid misdiagnosis.

　　2. Anesthesia selection

　　Most general hospitals do not pay much attention to hand injuries and often perform surgery with simple local anesthesia in the emergency operating room. However, due to the poor analgesic effect of local anesthesia and the small anesthetic range, this is not conducive to thorough debridement and comprehensive exploration of injuries, which is very easy to lead to incomplete debridement or missed diagnosis and treatment.

　　Generally speaking, it is recommended to choose brachial plexus block anesthesia for hand injuries, which can cover the entire upper limb basically and is convenient for using a tourniquet. This can not only reduce bleeding during the operation but also make the surgical field cleaner, which is conducive to improving the efficiency of surgery.

　　Of course, if it is only a finger tip injury and other skin flap transposition surgery is not considered, finger root anesthesia combined with the use of finger root tourniquet can be performed. The currently popular finger root anesthesia is to inject anesthesia into the flexor tendon sheath, which has the advantage of achieving anesthesia with only one injection, reducing the patient's pain, and ensuring the effect of anesthesia.

　　If there are multiple limb injuries, or if other parts of the skin flap or tissue flap transposition surgery is planned, or if the patient is a child who cannot cooperate with anesthesia, general anesthesia can be considered.

　　3. Emergency debridement

　　Emergency debridement of open wounds is crucial. The quality of debridement directly determines whether the patient's postoperative wound can heal in one stage and whether infection will occur. During debridement, efforts should be made to thoroughly remove necrotic, non-viable tissues, and severely contaminated tissues. Then, the wound surface should be repeatedly flushed with physiological saline, hydrogen peroxide, and iodophor. If necessary, secondary debridement should be performed, until the wound surface is clean and fresh.

　　Previous textbooks on hand surgery have emphasized thorough debridement, that is, to remove all contaminated tissues. After thorough debridement, reconstruction of some important tissues is carried out. However, for many important tissues (such as nerves, main arteries, etc.), once removed, the reconstruction effect may not be satisfactory. In addition, the advancement of modern antibiotic technology allows doctors to perform limited debridement in some cases, retaining some lightly contaminated important tissues, or only stripping the contaminated outer membrane tissues. By means of pathogenic culture and drug sensitivity test of local contaminated tissues, and supplemented with local or systemic use of antibiotics, the function of the affected limb can be preserved as much as possible.

　　For cases with severe contamination and long open wound time, the possibility of Clostridium perfringens infection should be considered. Therefore, before surgery, the wound exudate should be examined by smear to check for the presence of Gram-positive, large bacilli or capsules. If there is a suspicion of Clostridium perfringens infection, the operation should be performed in a single isolation operating room, and the surgical wound should not be closed in one stage (or the wound can be closed after repeated smears confirm that there are no large bacilli or spores). If conditions permit, hyperbaric oxygen therapy can be assisted after surgery.

　　4. Intraoperative injury assessment

　　During the operation, after debridement, the operating surgeon should further confirm the preoperative injury assessment results. If new injuries are found, they should be recorded in detail, and efforts should be made to repair them in one stage as much as possible.

　　5. Repair and Reconstruction

　　If the wound is not severely contaminated, it is advocated to perform the first-stage tissue repair and reconstruction for hand trauma, whether it is skin, tendons, or bones, nerves. If there are defects, in addition to some special cases, tissue transplantation should be performed because if it is勉强 to be matched, it is likely to cause tissue contracture or shortening, which will seriously affect function and appearance.

　　Of course, in the case of severe wound contamination, the一期 tissue repair is at certain risk. In this case, it is also possible to perform debridement first, and then perform tissue repair and reconstruction in the second stage.

　　6. Postoperative Management

　　The drainage tube in the hand wound is usually removed after 2 days, and if the wound is drained through a catheter, the time to remove the tube should be determined according to the amount of drainage. Generally, the tube can be removed when the drainage volume is less than 15ml within 24 hours. If there is no infection in the hand wound, it is not necessary to change the dressing frequently, and a dressing change can be performed once every 5 to 7 days. If there is a lot of exudate, the dressing can be changed every 1 to 2 days. If the patient's blood sugar is normal and there is no infection, the suture can be removed 12 to 14 days after surgery. For diabetics, the suture removal can be delayed.

　　For patients who have undergone reimplantation surgery of amputated fingers (limbs), concurrent vascular injury, or free tissue transfer surgery, it is necessary to minimize various factors that induce vasoconstriction after surgery to avoid surgical failure due to postoperative vascular crisis. First, it is necessary to minimize the stimulation of pain, which can be achieved by using analgesics, analgesia pumps, etc. Secondly, it is necessary to avoid the stimulation of cold and cigarettes. Of course, if it is possible to use appropriate antispasmodic and vasodilating drugs, it would be better, and it is also possible to use infrared lamps to照射 the affected limb.

　　For patients with concurrent vascular, tendon, and nerve injuries, it is generally necessary to use a cast for auxiliary fixation after surgery. Such casts usually need to be fixed for 3 to 4 weeks. During the period of cast fixation, do not remove the cast arbitrarily, otherwise it is easy to cause the re-tear of the sutured blood vessels, tendons, or nerves. After the cast is removed, functional exercise should be performed under the guidance of a doctor. For patients with special requirements or those allergic to the cast, various supports can also be used for fixation.

　　For patients who still have some functional disabilities after functional exercise, a second operation can be considered 4 to 6 months after the first surgery to release the tissues, repair or reconstruct the function.