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More than 30% of industrial accidents and approximately three-fourths of industrial injuries that cause partial disability involve the hand or hands.1 Each year, more than 16 million people in the United States seek emergency care for hand injuries, including amputations, fractures, infections, and ligamentous lacerations.
Successful evaluation and treatment of these injuries requires both knowledge of the relevant clinical anatomy of the hand and an understanding of the mechanism of injuries, complications, presentations, and disabilities the injuries produce. From an outcomes perspective, it should be stressed that the hand can only be fully functional if both sensation and appropriate motion are preserved.
With these considerations in clear focus, the purpose of this article is to review common injuries and infections of the hand. The goal is to provide a systematic, step-by-step approach that will guide the emergency physician through assessment and early therapy of the hand injury.
When it comes to hand injuries, appearances are often deceiving. Consequently, a comprehensive history of the injury and the patient's general condition are essential. Ensure that the ABCs of good emergency medical care are attended to, and do not be distracted from more serious injuries by a bleeding or deformed hand.
Two tasks should be given priority consideration. First, remove any rings, watches, or other jewelry with a ring cutter if necessary. This is important, because if the finger swells, the unstretchable metal ring will compromise circulation. Some patients may refuse to allow removal of a ring because of financial or sentimental value. If a patient persists in their refusal to have rings removed, you must warn them about the danger of vascular compromise and then have them sign an "against medical advice" form that documents this warning.
The second immediate task is to remove all clothing up to and including the chest. Some well-meaning bystander may have applied a tourniquet or the patient may have a more proximal injury. In extreme cases, the patient may have a chest injury. If the patient has been in a motor vehicle accident or industrial accident, be certain that no other injury exists or is masked by the pain of the hand injury.
History of the Injury. The patient's age, occupation, and dominant hand should be recorded. The ED physician needs to document whether the injury occurred in a clean or dirty environment. The circumstances in which the injury occurred also need to be recorded. Particular attention should be paid to injuries sustained in a fight; injuries involving crushing forces; injuries involving high-pressure air, paint, grease, or water hoses; burns caused by chemicals, steam, or electricity; and ring or jewelry injuries.2
Anytime the patient hears a snap or pop during the injury, the examiner should consider the injury to be serious. Certain activities or sports should increase the suspicion of specific injuries. Football, baseball, volleyball and basketball can have direct impact of the ball on a finger with resultant proximal interpharangeal (PIP) fractures or dislocations. Skiers and, to a lesser degree, baseball players may have thumb collateral ligament ruptures.
Initial Examination of the Hand Injury. The hand consists of five fingers (four fingers and the thumb), 14 finger joints, three major nerves, intrinsic and extrinsic muscles, and multiple intercarpal wrist joints among the ten carpal bones and the two bones of the forearm. Tissues specifically adapted for the function of the hand cover the hand. On the dorsum of the hand, the skin is thin and mobile. This skin stretches to completely cover without tension when the fist is clenched. The thin skin of the dorsum of the hand may be easily damaged in shearing type injuries. The palmar skin is adherent to the supportive fascia, and the fascia is adherent to the underlying skeleton. Even the fingerprint serves to increase friction and hence a more secure grasp of an object.
Frequently, injured hands are soiled and need to be cleaned before an adequate examination can be performed. Unfortunately, cleansing appropriately may require anesthesia. The safest approach is to check sensation before any anesthesia is used-even topical. If at all possible, get the patient comfortable in the supine position before starting the examination. Ensure that all jewelry is removed and that the patient's clothing is removed at least to the shoulder. Place the patient's hand on a firm support.
Start the examination by comparing the two hands for symmetry. Comparison with the uninjured extremity may show swelling from an infection, abnormal positioning from tendon or bone injury, color changes, or even lack of sweating. Note the presence of cyanosis, pallor, edema, erythema, ecchymosis, or blistering.
The location of the injury should be described as being on the radial or ulnar side and on the volar or dorsal (flexor or extensor) surface. Remember that the palmar aponeurosis and lymphatic drainage from palmar surface to the dorsum will cause infection or other palmar processes to be visible in the dorsum of the hand. If the patient has swelling of the dorsum of the hand, but is otherwise normal, turn the hand over. Often, a palmar puncture wound or other lesion will be found.
If the patient has an infected wound in the flexor tendon sheath of the digit, the palm of the hand may be quite tender. The flexor tendon sheath may conduct infection from these wounds directly into the palm of the hand. With fresh tendon injuries, blood in the flexor tendon sheath may cause pain on palpation of the sheath.
Vascular Status. The history of the injury may be helpful in suggesting the presence of vascular injuries. For example, a deep penetrating injury with subsequent pulsatile bleeding suggests arterial injury. This may be the only indicator of arterial injury, particularly in young, healthy patients. It should be noted that bleeding may stop rapidly in these patients due to spontaneous arterial retraction and constriction.
Check the skin color and then check for capillary refill. Repeat the test on an uninjured digit for comparison. The best place to test may be near the nail ridge. The pulp may be callous, or you may not be able to see refill in the pulp in patients with dark skin. Radial and ulnar pulses are often helpful if they are present and the patient has good color and capillary fill. If the radial and ulnar pulses are present and the patient has any signs of vascular trauma, use a Doppler probe. Doppler probes measure flow, while pulses indicate a pressure wave. The distinction is immaterial unless a flap or clot prevents flow but allows the pulse pressure wave to be transmitted. Digital pulses may not be palpable, but they may be auscultated with a Doppler probe.
The Allen test confirms that the patient has both ulnar and radial circulation and that there is collateral circulation between the two vessels through the palmar arch. Have the patient forcefully open and close the fist 10-20 times. The examiner should then compress the radial and ulnar arteries simultaneously as the patient opens the hand. When the ulnar artery is released, the patient's skin pallor should rapidly resolve. The process should also be reversed to ensure that the radial artery can perfuse the entire hand.
If the patient is bleeding, first try elevating the arm and applying a sterile wet-compression dressing. If bleeding continues despite elevation, a blood pressure cuff can be inflated to about 100 mmHg above the patient's systolic blood pressure. Never leave this cuff on for more than 30 minutes.
Since the nerves follow vessels, never ligate a hand vessel without directly visualizing the bleeding vessel and all surrounding structures. This will require better exposure, lighting, and instruments than are available in most EDs. Never blindly clamp a bleeding vessel. This invites trauma to nerve, tendon, or even associated vessels.
Neurologic Evaluation. Accurate diagnosis of a nerve injury in the hand requires knowledge of the distribution of the major nerves and a disciplined thought process. Be sure to examine the patient's sensation prior to instilling anesthesia. Lacerated nerves are common, particularly when the patient sustains a laceration over the known position of a mixed or sensory nerve.
The hand is supplied by three major nerves: the median, ulnar, and radial nerve. The ulnar and median nerve enter the hand on the palmar side. The radial nerve crosses the radial styloid from the volar to the dorsal surface at the wrist. These nerves control the wrist, fingers, and thumb's motion and sensation. (See Figure 1.) Loss of a major nerve at any level can compromise function of the hand.
Clinical tests for sensation and motor function should always be done to test integrity of the nerve. Although the patient's cooperation is helpful, most of these tests can be done without complete cooperation. Sensation should be assessed without disturbing the injured hand whenever possible. Digital nerve transection may result in a painful neuroma as well as insensitivity of the finger distal to the nerve injury. Using appropriate microsurgical techniques may minimize these complications, so referral for digital nerve injuries is mandatory.
Nerve repair need not be done emergently but can be delayed for a more complete evaluation within the first week following the injury. If a surgeon is available to repair the nerve within a day or so, then the wound can be cleaned and dressed without suturing or with loose suturing of the wound. A splint should be applied and the patient sent promptly to the surgeon for repair.
Sensory Examination. A major clue to loss of sensation in the hand that does not require the patient's cooperation is loss of sweating. The skin supplied by an injured nerve dries rapidly. Another test for the uncooperative patient may be O'Riain's wrinkle test. The hand can be immersed in hot water for about 10 minutes. The skin will not wrinkle if the nerve supplying it was severed.
If the patient can cooperate, two-point discrimination is quick and reliable. This test can be rapidly and inexpensively performed with a bent paper clip. Normally, patients should be able to discriminate two points at somewhat less than 5 mm. Ensure that the two points are oriented in line with the digital nerve, rather than transversely across two nerves' distribution. Pinprick (sharp/dull) testing may be misleading and may make other parts of the exam unreliable in children.
Motor Examination. A simple screening test of motor function can be performed by having the patient bring the tips of the thumb and all fingers in a circle around the examiner's pen. Then ask the patient to spread the fingers widely. Finally, ask the patient to spread the thumb away from the palm. It's not possible to do all of these maneuvers unless the ulnar, radial, and median nerve are all intact. If the patient can't do these, you must look for the specific deficit.
Simple and quick tests can be performed that correspond to the major patterns of muscle innervation. A mnemonic can be used to remember this simple battery of tests. "Look for the demon RUM to be opposed by the WCTU." RUM stands for the Radial, Ulnar, and Median nerves that are respectively opposed by Wrist extenders, Claw hand, and Thumb Up maneuvers.
The radial nerve innervates the extrinsic wrist and fingers in extension, the ulnar deficit will cause a claw hand formation, and the median nerve is needed for the thumb up maneuver. Having the patient cock the wrist back (dorsiflexion) against resistance and then completely extend all fingers can check the radial nerve. (See Table 1.) If the patient can't extend at all, then look for nerve damage. If the patient can move it, but does so weakly, then painful range of motion may be at fault rather than nerve injury.
A wrist drop should clue the examiner that there may be a problem with the radial nerve. The radial nerve is close to the brachioradialis and the flexor carpi radialis tendons in the proximal wrist. If these tendons are damaged, look for injury to the radial nerve. If the little and ring fingers claw, look for damage to the ulnar here.
The ulnar nerve innervates all the intrinsic muscles of the ring and little fingers. (See Figure 2.) If the index and middle fingers claw, both the ulnar and median nerve must be damaged, since some intrinsic muscles are innervated by each.
Another important test of ulnar nerve function is to ask the patient to form an "O" with thumb and index finger. If the circle is askew (caved in), look for ulnar nerve damage with loss of thumb adductor function. This is called "Froment's sign."
Check for contraction of the second dorsal interosseous muscle as a further test of the integrity of the ulnar nerve. Ask the patient to abduct the extended index finger against resistance and palpate the webspace of the radial side of the second (index finger) metacarpal. Since the ulnar nerve is just deep to the flexor carpi ulnaris, suspect an ulnar nerve injury if the tendon is damaged. Having the patient bring the thumb out of the palm (toward the ceiling when the dorsal surface of the hand is flat on the exam table), while you palpate the thenar eminence and check function of the median nerve.
If the patient can't point the thumb up, then the intrinsic opponens and abductor function is lost. (See Table 1.) Remember that the median nerve supplies half a LOAF-half of the Lumbricals (the index and middle fingers) the Opponens, Abductors, and superficial half of the Flexor muscles of the thumb. It also supplies the flexor side of the forearm, so if the median nerve is damaged anywhere above the wrist, the patient will not be able to pronate the palm down. The median nerve is superficial right around the carpal tunnel. Lacerations about this area may point to damage to the median nerve.
Repair of a lacerated nerve demands an operating room, an experienced hand surgeon, good microinstruments, and an operating microscope. These techniques are beyond the scope of most emergency physicians and should usually be referred. Never "tag" nerve ends; if the surgeon needs a "tag" to find the nerve, find another surgeon.
A laceration of a mixed motor and sensory nerve such as the ulnar or median nerve should be repaired as a primary procedure if at all possible. Isolated lacerations of sensory nerves such as a digit may often be best repaired three or four days later. In some cases, sensation will return if the nerve is bruised (neuropraxia), and, in others, a better exam with a less painful hand will be more accurate.
Range of Motion. Recognition of tendon injuries requires a systematic examination of the flexion and extension of each finger at each joint. Although some tendon injuries can be seen in the depths of the wound, the most reliable way to detect injuries is functional testing of the hand. It is sometimes helpful to demonstrate the various normal motions and then have the patient mimic them. This is particularly helpful in examination of children.
Patients who are unable to flex one finger together with the others will often be found to have a tendon injury. Weak movement of the joint may mean that the tendon injury is incomplete. (It may also mean that the patient has too many other injuries and is simply moving the finger inadequately. This is a difficult judgment call.) Remember that some uninjured parts of the hand may not move normally if there is an injury close by. Some injured structures may be moved by uninjured parts of the hand. Occasionally, the fifth digit may be extended by the extensor communis, despite a fifth digit extensor tendon laceration.
Rarely, a partially lacerated tendon will rupture during or after the examination and leave a complete tendon laceration. This can be appropriately repaired. Pain along the course of a tendon during motion is a nonspecific indication of injury. Because the vessels and nerves are so close to the flexor tendons, any injury that clearly involves one of these is likely to involve the others. Before any direct examination of the wound, ensure that both sensation and vascular status are recorded.
Flexion. There are two flexor tendons to each digit and one to the thumb. The deep digital flexor tendon inserts on the distal phalanx and flexes all joints during motion. It is the most important of the flexors and is tested by strong flexion of the distal joint. The profundus tendon produces all of the flexor strength at the distal interphalangeal (DIP) joint and more than half of the strength at the PIP joint. To test the deep digital flexor tendon, restrain the PIP joint and have the patient attempt to flex the DIP joint.
The superficial digital flexor tendon attaches to the middle phalanx. The tendons are formed in the forearm, pass through the carpal tunnel at the wrist superficial to the profundus tendons, and through the digital fibroosseous sheaths to a broad insertion on the middle phalanx.3
Movement of this tendon causes flexion of the proximal interphalangeal joint. Isolated injuries of this tendon are uncommon. To test this, hold three fingers and have the patient attempt to flex the fourth at the PIP joint. Test each finger in this way. Often the fifth digit superficial tendon may not be independent, small, or even absent. About 15% of people cannot actively flex the PIP of the fifth digit without flexing the adjacent ring finger PIP simultaneously.4
If there is a laceration of the flexor tendon sheath, then it should be assumed that the patient has a laceration (partial or complete) of the flexor tendon until proven otherwise. The wound should be carefully examined, including examination with the hand flexed as it was during the injury. If the digit was flexed at the time of the injury, then skin, tendon, and sheath will all be lacerated at different levels when the digit is extended.
Extension. Have the patient place the hand palm-down on a table and extend the fingers off the table one at a time. If you suspect an extensor tendon laceration but can't see one in the wound, try putting the hand in the position it was in when the injury occurred. This often shows an extensor tendon injury. Moving the appropriate finger also increases the chances of seeing a tendon injury in the wound.
Repair of Tendon Injuries. The extensor tendons are superficial and not constrained by a tight tendon sheath. This means that they can be relatively easily located and repaired, unlike flexor tendons. If the emergency physician has experience, training, appropriate tools, lighting, and exposure, and has a patient with a clean wound, then repair in the ED is possible. If all of these are not available, then the patient should be referred to a hand surgeon for repair in an operating room.
Flexor tendon injuries are not suitable for emergency repair. Although these injuries have been divided into several zones to identify complications associated with repair, classification of the injury does not change the appropriate emergency management of the patient.5 These injuries should be referred to a qualified hand or orthopedic surgeon for repair. This may be done within a few days if the wound is carefully cleansed and the skin is loosely closed over the injury.
Cleansing the Injured Hand. Do not use scrubs and cleanser solutions such as iodine and hexachlorphene directly on a wound. These substances may delay healing by shortening the life span and decreasing the migration ability of the polymorphoneucleocyte. These solutions may be used to disinfect the surrounding epidermis.
Large volumes of water delivered at high pressure are the best way to remove debris in the wound. There are many opinions about the best way to irrigate a wound, but almost all of these methods are controversial. There are multiple commercial aids to help with this irrigation, but all add expense to the procedure. About the only noncontroversial method of irrigation is to use an 18g or 19g needle and a 30cc syringe full of saline with rapid firm pressure.
Plain Film Radiographs. In all but the most minor lacerations or contusions of the hand, a standard series of radiographs should be obtained. These radiographs help to identify joint injury, fractures, or dislocations. They also help to locate retained foreign bodies. A laceration from glass or other foreign body such as porcelain should almost always have a radiograph of the hand to insure that no foreign body remains. X-rays should be obtained for all gunshot wounds.
Three views of the hand should always be obtained. These include a posteroanterior (PA), a true lateral, and an oblique presentation. Oblique views are essential to identify the metacarpal heads. The Brewerton view can demonstrate small fractures of the head of the second through the fifth metacarpals.6
If a phalanx is injured, then the beam should be centered on the phalanx and a PA of the entire hand and a true lateral and oblique projection of the injured digit. Eccentric soft-tissue swelling noted on one side of an interphalangeal joint is suggestive of a collateral ligament injury to that joint.
Small avulsion fractures may be noted with a mallet finger, avulsion of the profundus tendon from the insertion, or avulsion of the palmar plate of the phalanx. Scaphoid views show the entire length of the scaphoid bone. The fingers are flexed into a fist and the thumb is held straight. Both the wrist and the fist lie flat on the film. This dorsiflexes the long axis of the scaphoid into a plane that is parallel to the film. A second view is added with ulnar deviation of the wrist.7 Some acute fractures, particularly scaphoid fractures, are difficult to visualize. Osteolysis causes the fracture line to be more radiolucent some 7-10 days after the fracture.
It is often appropriate to splint patients based on the history and physical examination, even if the radiographs appear normal. A key to the identification of dislocations of the carpal bones is the position of the lunate in the lateral projection. The capitate rests in the concavity of the lunate, which in turn rests in the distal concavity of the radius. In a dorsal perilunate dislocation, the capitate is dorsally displaced out of its normal position in the lunate. In the palmar dislocation of the lunate, the capitate remains in line with the radius, but the lunate bone is displaced towards the palmar surface.
Other occult fractures and some dislocations may be heralded by loss of fat pads, soft tissue swelling, or changes in the angulation of the carpal bones. A gap greater than 2 mm between the scaphoid and the lunate is diagnostic of scapholunate dislocation.8
Special Studies. If initial films of hand injuries do not visualize an opaque foreign body, consider a xeroradiogram of the hand. These are better for wood and plastic foreign bodies than plain film radiograms. In patients with persistent pain from an injury to the hand, computed tomography (CT), scintigraphy, or MRI may be used to identify an occult fracture.9 In occult fractures of the radius, scaphoid bone, or the hook of the hamate bone, MRI may allow early evaluation of avascular necrosis.10
MRI may also be used to evaluate the soft tissue injury of distal avulsion fractures in patients with suspected trigger finger injuries or gamekeeper's thumb. Both MRI and CT can be used for identification of foreign bodies in the hand. An emergency physician would rarely order these studies.
Amputations. Amputations represent about 5% of upper extremity injuries and involve about 150,000 people in the United States each year.11 Reimplantation of amputated digits has become commonplace. Survival and function depend on many factors including the type of injury, ischemia of the injured part (particularly if warm), and the patient's general condition and prior medical illnesses. Most surgeons would recommend reimplantation of a thumb, the index finger proximal to the PIP joint, multiple digits, and single amputated digits in children.12
Generally, sharp injuries do much better than crush or avulsion injuries.13 Hemophilia and sickle cell disease are strong relative contraindications. Remember that replantation of an amputation means that there is a prolonged healing time of many months.
Amputated or devascularized digits should be cooled as quickly as possible. Proper cooling of the amputated digit or extremity markedly extends the time that the amputated part can survive before revascularization. The amputated part should be placed in saline soaked gauze and put in a sealed container such as a baggie, on ice. The parts should not be immersed in nonphysiologic solutions and should never be frozen.
Survival rates of amputated parts may approach 90% in some centers, but survival of the digit does not necessarily mean that full function has been restored. To avoid unrealistic expectations on the part of patient and family alike, ensure that all understand that the decision to replant a digit or hand will be made by the surgeon at the referral center after a thorough examination.
Ring avulsion injuries may run the spectrum from a minor skin injury to complete avulsion of the digit with flexor tendon from the forearm.14 Simple avulsions with small amounts of skin may be safely repaired. If the skin is denuded from the finger, there may be a great desire to simply roll the skin envelope back onto the digit and suture it into place. This, unfortunately, may not restore sensation or blood flow to the skin. A hand surgeon should see these complex injuries.
Crush injuries. A crush injury to the hand is one of the most unpredictable and potentially devastating injuries. Because of the unique functions of the hand and the lack of protective muscle mass, the hand is particularly vulnerable to crush injuries. These injuries may involve multiple tissues and may have both normal and irreversibly damaged tissues side by side. Open wounds, massive levels of contamination, and thermal injuries often complicate these injuries.15,16
Ischemia may result from damage to local microcirculation from the crush, from damage to major blood vessels, or a combination of these. Severely mangled hands may require amputation or revascularization.17
Closed injuries. Closed or "roller" or "wringer" injuries of the hand and forearm are often much more serious than initially suspected. When the patient's hand is caught between two compressing rollers, hemorrhage deep within the muscle and fascial planes may be found. If the patient has pain on passive extension of the digits, then deep hemorrhage may be causing compression in the muscle compartments. In this case, decompression by a hand surgeon is indicated.
Forearm muscle compartment pressure may be monitored with Wick catheters. If immediate decompression is not needed, then the patient should be admitted to the hospital for hourly neurovascular monitoring for 24 hours. A bulky dressing with the elbow flexed, the wrist slightly extended, and the MP joints slightly flexed (anatomic position) should be applied. The arm should be elevated and ice applied.
Dislocations. Fingers can dislocate in a variety of directions. Dislocations, fractures, and ligament disruptions may present with identical deformities. Ensure that the patient has "only" a dislocation and not a fracture or fracture dislocation with a radiograph prior to any reduction maneuver.
Be certain that an adequate history of the injury is obtained. A finger that is forced upward may cause a volar plate rupture or dorsal dislocation. A finger that has been compressed is more likely to have a fracture or mallet finger. A joint that is pushed sideways should prompt the emergency physician to think of a collateral ligament injury.
Dorsal dislocation of the PIP joint produces a characteristically excessive prominence of the middle phalanx. This causes a distal rupture of the volar plate. It is often termed a simple dislocation since non-operative management is almost uniformly successful.
Reduction may be done with direct traction to the digit, followed by mild hyperextension. The physician may add direct pressure over the base of the middle phalanx as traction is applied. It may be remarkably easier and much less painful for the patient to use a digital block prior to the reduction maneuver. Ensure that the finger is well-aligned after the reduction.
The reduction is stable if the patient does not displace with usual range of motion or gentle lateral stressing. The joint should be splinted for three weeks with a foamed aluminum dorsal splint. After three weeks, unrestricted motion should be encouraged.
In some patients, rupture of the volar plate does not result in dislocation. The usual deformity is absent and only a small avulsion fracture is found at the base of the middle phalanx. These patients require splinting and referral to a hand surgeon. If there is a large fragment, then the patient may need operative reduction and stabilization of the fragments.
Anterior dislocation of the PIP joint is more easily overlooked on physical examination. The classic deformity of the dislocation is missing and the patient may be holding the finger in flexion. This should be suspected if the patient has a tender joint on palpation and is unable to extend the finger. In these patients, the extensor mechanism is often damaged and operative repair is often needed. These injuries should be splinted and the patient referred to a hand surgeon. If the injury is misdiagnosed because no radiograph was obtained, the patient may develop the boutonniere deformity.
Dislocation of the metacarpal joint may result in a proximal rupture of the volar plate and dorsal displacement of the proximal phalanx. In some patients, the volar plate becomes trapped in the joint space and simple reduction is not possible. Reduction of the simple metacarpal joint dislocation requires flexion of the wrist to relax the flexor tendons. Steady pressure is applied on the dorsal surface of the proximal phalanx. The phalanx is lifted up and over the metacarpal head into the reduced position. Excessive traction may cause the volar plate to enter the joint space and convert a simple dislocation into one that requires operative reduction.18
Phalangeal fractures are among the most common of hand fractures. The majority of these are stable injuries that can be adequately treated by simply buddy-taping them to the adjacent finger. Simple splinting with foam and aluminum splints for 14-21 days is another option.
Distal Phalanx. The most common distal phalanx fracture is the comminuted tuft fracture. Usually, angulation and distraction of the fragments is minimal because the phalanx is splinted dorsally by the nail matrix and volarly by the fibrous septa of the pulp. These fractures may be treated by splinting the finger. A foam and aluminum splint that extends from dorsal to volar surface up and over the distal tuft will provide more protection for the patient's distal fingertip than a dorsal or volar splint alone. Splint from the proximal phalanx to proximal phalanx and instruct the patient to keep the splint in place for 14 to 21 days.
Subungual hematomas may produce significant throbbing pain from the pressure on the nail bed. Small subungual hematomas may be relieved by simple decompression of the hematoma.19 If the subungual hematoma is more than about 25%, then elevation of the nail and inspection of the underlying nail bed is more appropriate therapy. If there is a transverse fracture with displacement of the fragments, then a nail bed injury is common. Nail bed lacerations should be repaired by elevation of the nail and repair of the nail bed.
Volar and Dorsal Fracture Dislocations. Volar and dorsal fracture dislocations occur when the distal interphalangeal joint is not only fractured but also dislocated. In volar fracture dislocations, the distal phalanx is subluxed volarly and the dorsal fragment is displaced by the tension of the extensor tendon. In dorsal fracture dislocations, the distal phalanx is subluxed dorsally and the deep flexor tendon displaces the volar fragment. These injuries will often require open reduction and internal fixation of the fracture fragments.
Dorsal articular fractures in adults can cause a "mallet finger" deformity or "drop finger" as described above. There is considerable controversy about the best method of treatment for these injuries and options range from surgical exploration and fixation of the fragments to splinting alone. Certainly, the emergency physician's best course of action is to splint the injury and allow the hand surgeon to weather the controversy.
Proximal Phalangeal Fractures. These fractures may be treacherous and require open fixation and immobilization. Often the oblique x-ray does not show the true nature of the fracture, and a true lateral radiograph is needed to show the anterior angulation of the fracture. If this angulation is present, then the function of the tendon will be significantly impaired. Unstable fractures are usually rotated, spiral, or comminuted fractures.
Metacarpal Fractures. Metacarpal neck fractures are very common, particularly neck fractures of the fourth and fifth metacarpal (Boxer's fracture). They are usually the result of crush or direct impact injuries.
Most of these metacarpal neck fractures can be treated with closed reduction and casting. If there are several large fragments, open reduction and internal fixation are often recommended.20 Assess for rotational deformity by having the patient slowly make a fist with the palm facing upward.
With a rotational injury, the nails will no longer be in line and the finger may be obviously rotated. If there is any significant rotational deformity, this must be corrected. The fourth and fifth metacarpals may have up to 30° of rotation before reduction is necessary, but little rotational deformity is tolerated for the second or third metacarpal. Reduction of the fracture is generally beyond the training of most emergency physicians, and referral to an orthopedic or hand surgeon is appropriate.
For fractures of the fourth and fifth metacarpals, an ulnar gutter splint with the joints in about 60° of flexion is appropriate. Fractures of the second and third metacarpals can be treated with a radial gutter splint. For these splints, a hole must be made in the splint for the thumb.
Metacarpal shaft fractures can be transverse, oblique, or comminuted. Transverse fractures are usually due to a direct blow to the hand, while oblique fractures are the result of rotational forces to the hand. Transverse fractures may have unacceptable angulation, while rotational deformity may complicate oblique fractures. Either may be unacceptable and require reduction and fixation. This is best done by an orthopedic or hand surgeon.
Comminuted fractures of the metacarpal shaft are often associated with significant soft-tissue injury to the hand. These lesions should be treated by a hand or orthopedic surgeon and may require substantial surgical repair of the other lesions.
Metacarpal base fractures are usually the result of compression in line with the bone or from a direct blow. They may involve the joint, may be rotated, and may be stable or unstable. If the fracture is stable and does not have joint involvement, splinting followed by routine orthopedic referral is appropriate.
Displaced fractures of the metacarpal base or shaft are also unstable. Intra-articular fractures should be referred to an experienced orthopedic surgeon for management. Fractures of the thumb metacarpal are most common at the base of the thumb. The two most common intra-articular fractures of the thumb are Bennett's fracture and Rolando's fracture of the thumb.21,22 Bennett's fracture is a fracture dislocation that characteristically has an intra-articular fracture through the base of the metacarpal bone with an ulnar fragment that is pulled medially and ulnarward.
The rest of the bone is dislocated dorsally and radially by the pull of the abductor pollicis longus muscle and the adductor pollicis muscle. These fractures often require closed reduction and percutaneous pinning or open reduction and internal fixation.
Occasionally, the force that would cause a Bennett's fracture will produce a dislocation by rupturing the anterior oblique ligament that bridges the metacarpal base and the trapezium. The treatment is immobilization, but the injury may still cause an unstable joint and traumatic arthritis.
Rolando's fracture is similar to a Bennett's fracture but there is a comminuted Y or T fracture pattern. These complicated fractures deserve the prompt attention of a hand surgeon to maximize function of the thumb.
The hand has a unique anatomic arrangement that makes it possible for infections to extend throughout the various planes of the hand without resistance. Infections that start in the fingers may proceed through the flexor tendon sheath and enter the mid-palmar space. Pressure in the mid-palmar space extends rapidly into the thenar space. The resulting infection may be devastating for the entire hand and may occur despite massive treatment with antibiotics. These patients will require incision and drainage in the operating room.
The four cardinal signs of a flexor tenosynovitis are tenderness over the flexor tendon, swelling of the finger, pain on passive extension, and a flexed posture of the digit. The tendons have scanty blood supply and blood flow is easily interrupted by relatively little edema. An infection within the tendon sheath decreases this blood supply, and often destroys the underlying tendon. Peritendonous scarring may result in subsequent loss of function of the hand. These patients require prompt drainage in the operating room and should be admitted with appropriate intravenous antibiotic therapy.
In about half of the patients, there is communication between the ulnar and the radial bursae. This may cause a horseshoe shaped abscess in the palm. An additional concern is the "collar button" abscess. A palmar infection may extend through the intermetacarpal spaces to the dorsum of the hand. These abscesses may "point" both dorsal and volar.
Most hand infections require intravenous antibiotics and surgical drainage of the infection. This is not the usual province of the emergency physician, and these patients should have a hand or orthopedic surgical consult. Three specific types of hand infections may be treated by the emergency physician: the paronychia, the herpetic whitlow, and the felon.
Paronychia. An infection around the margin of the nail bed is a paronychia. The portal of entry is often between the nail and the soft tissue of the nail gutter. The collection of pus may extend under the nail and damage the nail bed. If treated early, a simple incision with a pointed blade along the nail fold will allow this infection to drain adequately. If there is pus under the nail, then the proximal end of the nail must be elevated and incised to expose the entire area of infection. The wound is left open, and antibiotics are only rarely needed for successful treatment of this infection. Warm soaks may be helpful. The most common organisms are Staphylococcus aureus and Streptococcus species.
Felon. A felon is a subcutaneous infection of the pulp space of the fingertip. This anterior closed space often can become infected after a puncture wound. The resulting infection is extremely uncomfortable. The swelling that ensues can compromise perfusion predisposing the patient to necrosis of the pulp, infection of the bone, and a chronic infection. A felon must be drained by a longitudinal incision along the lateral nail margin and extending along the tip of the finger just below the distal nail margin.
This will allow drainage of all of the septal spaces in the anterior closed space and adequate decompression of the wound. A "fishmouth" incision is not necessary for complete healing of this lesion. The most common organism is Staphylococcus aureus, and appropriate antibiotics are indicated.
Herpetic Whitlow. Herpetic whitlow is a viral infection of the fingertip. The lesions will be cutaneous bullae. The most common organism is Herpes species, but multiple digital involvement may also be seen with Coxsackie virus. The patient may be treated with antiherpetic agents such as Zovirax. A dry dressing should be used. These lesions may occasionally be misdiagnosed as a felon.
Lacerations. Simple, tidy, superficial hand lacerations can be readily closed.23 The wound must be cleansed as earlier described, cleared of dirty tissue, and closed. Even if the laceration is 6-10 hours old, infection is unlikely. Contaminated wounds are a different matter, of course. If the wound cannot be debrided to the appearance of an elective surgical wound, then it should be left open, packed with fine mesh gauze, and closed in 3-5 days. (This is known as delayed primary closure or DPC.) If there is any doubt about the cleanliness of a wound, then DPC is safest.
Fingertip Injuries. Distal fingertip amputations can be treated openly without grafting and preserve the maximum amount of length. Healing by secondary intention can be accomplished without infection, with good return of normal sensation, and with preservation of joint mobility.24 The healing tissue will pull normal tissue from the pulp to the very tip of the finger. This means that the pulp is free of scar tissue and is markedly less tender. The tip may have an adherent tender scar, but the pulp with grip and sensation is not tender.25
Fingertip Amputation. One of the most common problems in any ED is the amputated fingertip. The major object of our treatment must be the early rehabilitation of the hand with a painless and durable skin cover. There are a multitude of techniques that may involve complicated and novel skin flaps that have been developed for these injuries.
Nail-bed Injuries. The fingernail is a vital component of the hand, protecting and supporting the fingertip. It acts as a firm base so that our fingertips have enhanced sensation. Appropriate initial treatment of nail bed injuries will decrease deformity, discomfort, and help the nail heal. Nail-bed injuries can include lacerations, crush injuries to the nail, and avulsions of the nail. An avulsion may be incomplete with nail remaining attached to the underlying nail bed or complete separation of nail from nail bed. If the nail remains intact it can obscure the extent of the underlying damage. Likewise, an extensive subungual hematoma can obscure deeper damage to the nail bed. In these cases, removal of the nail and repair of the nail bed is appropriate.26
The radiograph may show a transverse fracture of the distal phalangeal tuft or an epiphyseal growth plate separation injury. This should be considered as an open fracture and the patient's wound should be irrigated and thoroughly debrided then fracture fragments reduced as appropriate. Suspect a nail bed laceration if the fragments are separated.
If the fracture fragments are unstable, then they need to be fixed in place with a fine Kirschner wire. This is best left to an orthopedic or hand surgeon unless the emergency physician has the training, time, and tools available to repair the injury appropriately.
The nail bed should be carefully inspected and any fragments restored to position. The nail bed margins need to be accurately approximated with 6-0 or 7-0 absorbable sutures. Lacerations of the fold and the fingertip pulp should be approximated and repaired.
If available, the nail is cleansed, trimmed, and replaced within the nail fold as both an organic splint and dressing. If the nail is not available or too damaged, then non-adherent dressing should be used. Without support of the palmar pulp tissue, about 25% of patients will have a tendency for the nail to grow over the end of the finger (a hooked nail). Routine nail grooming should provide relief for this injury.
Ligamentous injuries: Collateral Ligament Injuries (Gamekeeper's Thumb). Stability of the metacarpophalangeal joint of the thumb is maintained by an arrangement of capsular, ligamentous, and musculotendinous supporting structures. Mediolateral stability is principally provided by the strong collateral ligaments, which start at the metacarpal condyles and pass obliquely toward the palm and attach on the volar third of the proximal phalanx and volar plate. Ulnar collateral ligament injuries of the thumb are particularly common among skiers and ball players. They occur more frequently than radial collateral injuries. Injuries are often termed "gamekeeper's thumb."
This term is derived from anecdotal reports of British gamekeepers breaking small animal's necks by using the thumb as a wedge.27 The mechanism of injury is forced radial deviation-abduction often combined with hyperextension of the metacarpophalangeal joint. This can cause a complete or partial rupture of the ligament. This injury may be accompanied by an avulsion fracture at the site of the insertion of the collateral ligament at the volar base of the proximal phalanx. In most cases, however, the injury is purely ligamentous and the radiographs are normal.
Joint effusion and tenderness over the collateral ligaments are nonspecific indicators of collateral ligament tear. If the patient's joint opens with stress testing, there is no question of the collateral ligament injury, but pain and muscle spasm may limit passive abduction of the thumb and give a false negative result. Examination under anesthesia may reveal an injury when pain and muscle spasm intervenes, but this is usually left to the orthopedic or hand surgery consultant.28,29
Emergency therapy is a thumb Spica splint and referral to a hand or orthopedic surgeon for definitive care. The final treatment depends on whether the ligament tear is partial or complete. Partial tears respond well to immobilization for 3-6 weeks in a thumb Spica cast. Surgery is often recommended for complete tears. Associated fractures are also indications for repair if they involve 25% or more of the articular surface or if an avulsion fracture is displaced more than 5 mm.
Sprained Finger. Sprained finger is a diagnosis often made. Unfortunately, it should be reserved for patients who have had a thorough physical and radiographic evaluation of their injury. Several injuries masquerade as a sprain that requires more definitive treatment.
Mallet Finger. Disruption of the terminal extensor tendon mechanism can occur when a baseball or other object strikes the end of the finger. Three types of "mallet or baseball finger" can occur: disruption of the extensor tendon, avulsion fracture at the base of the distal phalanx (clinically this injury is indistinguishable from a laceration of the extensor tendon.), and a volar fracture subluxation of the distal joint. All three will have the classic drooping finger deformity. The difference can only be seen on x-ray.
Boutonniere Finger. A sharp force against the tip of the partially extended finger will result in hyperflexion of the middle joint and may rupture the insertion of the central slip of the extensor tendon into the base of middle phalanx. The middle joint becomes "buttonholed" between the two lateral extensor tendons. On examination, the emergency physician should look for point tenderness about the base of the middle phalanx and for diminished extensor tendon strength with increased pain when the middle joint is extended against resistance.
Treatment is splinting the joint in complete extension for four weeks. Surgical consultation for continued care is appropriate. Flexor digitorum profundus avulsion. The patient may also avulse the insertion of the flexor digitorum profundus tendon by forced extension of the finger when the flexor profundus is contracting. This happens when the finger is caught in a loop or pocket. The patient is simply unable to flex the tip of the finger. X-ray findings are usually normal, although a small avulsion fracture may be noted.
Collateral Ligament Injuries. Collateral ligament injuries of the fingers are less common than of the thumb as described above. In most cases, these can be splinted to an adjacent digit. If there is obvious deformity or instability, then operative repair and referral to a hand surgeon is indicated.
Foreign Bodies. When evaluating a puncture wound or laceration of the hand, the emergency physician must consider the possible presence of a residual foreign body in the tissues. The physician often misses initial diagnosis of the foreign body.30 The best defense for missing a foreign body is to document an adequate history, adequately explore the wound, and obtain a radiograph of the hand. In general, foreign bodies of the hand require removal. The major question is when to remove them. Circumstances under which foreign bodies should be removed within the first 96 hours include:
Considerations for timing of the removal include the location of the foreign body, the material of the foreign body, the existence or anticipation of infection, the functional or anticipated impairment, and the general condition of the patient. Unfortunately, removal of foreign bodies in the hand can be time-consuming and even dangerous when attempted without adequate anesthesia, hemostasis, exposure, and lighting.
It is equally unfortunate that unplanned delayed removal of a foreign body may be associated with more legal complications than medical. Ensure that a radiograph is obtained whenever there is a suspicion of a retained foreign body. Metallic foreign bodies are generally non-reactive and easily visualized on radiographs. Glass fragments are notoriously difficult to see in tissues but are quite easy to see on a radiograph.
Small fragments of these two materials may usually be removed on a delayed basis without significant complication. Wooden splinters are often parallel with the skin surface and can be either deep or parallel to the skin surface. In many cases, the splinter can be palpated. Unfortunately, the patient or well meaning friend may grasp the splinter with pliers or even forceps and attempt to remove it. This will often leave behind fragments of wood or thorn deep within the tissues.
The appropriate treatment is to open the entire tract and remove the foreign body with direct visualization. In general, wooden foreign bodies should be removed as soon as practical. Subungual splinters are a special case. These are often quite painful and may be wood, metal, or even plastic. Often the patient is seen after several home attempts to remove the splinter have occurred. These attempts may either leave fragments of the splinter behind, or may push fragments deeper under the nail. At this point, it is often easier on the emergency physician and the patient alike to instill a digital block, sharply incise a window of nail plate above the splinter and remove the splinter with direct visualization.
Puncture Wounds. The surface wound may be misleading when dealing with puncture wounds. Simple puncture wounds may be cleaned both before and after the removal of the penetrating object. Wounds produced by staples, nails, and needles may penetrate bone or introduce gross contamination into the hand. Tetanus immunization is particularly important in these wounds.
If the penetrating body punctures bone, carries in a plug of skin or a contaminating foreign body, then formal exploration is also required. These wounds must be opened, irrigated, debrided if necessary, and allowed to heal by secondary intention. If the flexor tendon sheath is penetrated, then surgical consultation is indicated and the patient should be referred.
Fight Bites. Human bites (fight bites) are among the most dangerous contaminated wounds that an emergency physician treats. They require thorough surgical debridement and excision to prevent any deep infection. Fight bites must be treated with antibiotics because they have an infection rate as great as 50%.31 Staphylococcal species, Streptococcus species, and Eichenella corrodens are the most common isolates.32 Eichenella corrodens will cause rapidly spreading cellulitis with profound tendon damage if present. Treatment is a first generation penicillin or amoxicillin/clavulanate or cephalosporin. Antistaphylococcal penicillins will not adequately cover this organism.
High-Pressure Injection Injuries. Grease gun, paint sprayers, or compressed air devices may produce serious penetrating injuries that require wide debridement.33 High-pressure injection devices may generate pressures that range from 1500 to 7000 psi and deposit substantial quantities of material into tendon and synovial sheaths.34 The most common site of injection is the index finger followed by the palm and long finger.35 The patient may develop intense throbbing and pain shortly after the injury.
Chemical properties of the substance injected may contribute to the severity of the injury. Paint and paint solvents appear to be the most irritating to tissue. Swelling due to injury, substance induced irritation, and material deposited within the sheath may rapidly compromise circulation to the digits.
The classic treatment of these injection injuries is early extensive surgical debridement and decompression of the wound. Prophylactic broad-spectrum antibiotics are often used in these patients, but there is no controlled data about their efficacy and cultures are frequently negative.36 Corticosteroids have been used, but again there is no controlled data about efficacy or complications.
Hand injuries result from many different traumatic events, including crush injuries, amputations, fractures, and dislocations. Much of the treatment of hand injuries falls within the province of the emergency physician. Initial assessment and stabilization can change the course and decrease morbidity in a patient with a significant hand injury.
A thorough examination should always be both performed and documented. The emergency physician should closely inspect the hand and then perform a thorough sensation, ligament, and motion examination of the injured hand. Remember that examination for tendon injuries can be misleading due to partial tendon injuries. Copiously irrigate all open wounds and explore them for tendon, tendon sheath involvement, and foreign bodies.
Administer appropriate antibiotics for bites, contaminated wounds, and wounds that involve open fractures, amputations, and tendon injuries. Admit those patients with a tendon or joint infection and those with palmar infections. Seek hand surgery consultation when the patient has an amputation, a deep space infection, flexor tendon lacerations, or an unstable or angulated fracture.
1. Markovick VJ, Pons PT, Wolfe RE. Emergency Medicine Secrets Philadelphia: Hanley and Belfus, Inc; 1993.
2. Gillespie CA, Rodeheaver GT, Smith S, et al. Airless paint gun injuries: definition and management. Am J Surg 1974;128:383-391.
3. Rooks MD. Rock climbing injuries. Sports Med 1997;23:261-270.
4. Rooks MD. Rock climbing injuries. Sports Med 1997;23:261-270. OP CIT.
5. Herndon JH. Tendon injuries-flexor surface. Emerg Med Clin North Am 1985;3:341-349.
6. Brewerton DA. A tangential radiographic projection for demonstrating involvement of metacarpal heads in rheumatoid arthritis. Br J Radiol 1967;40:233-235.
7. Stecher WR. Roentgenography of the carpal navicular bone. Am J Roentgenol 1937;37:704-705.
8. Frankel VH. The "Terry Thomas" sign. Clin Orthop 1977;129:321-322.
9. Eustace S, Denison W. Pictoral review: Magnetic resonance imaging of acute orthopedic trauma to the upper extremity. Clinical Rad 1997;52:338-344.
10. Horton MG, Timins ME. MR imaging of injuries to the small joints. Imaging Orth Trauma 1997;35:671-700.
11. Cunningham BL, Shons AR. Upper extremity replantation surgery. Minn Med 1982;65:463-466.
12. Moore JR, Weiland AJ. Current concepts of digit replantation. Am Fam Phys 1981;24:121-125.
13. Stevanovic MV, Vucetic C, Bumbasirevic M, et al. Avulsion injuries of the thumb. Plast Reconstr Surg 1991;87:1099-1104.
14. Burkhalter WE. Ring avulsion injuries, care of amputated parts, replants, and revascularization. Emerg Med Clin North Am 1985;3365-3371.
15. Buchler U, Hastings H II. Combined Injuries in Operative Hand Surgery New York: Churchill Livinston; 1993.
16. Muir L, Foucher G, Marin-Braun F. Ax injuries of the hand. J Trauma 1997;42:928-932.
17. Bomar KS, Calandruccio JH. Crush injuries to the hand and forearm. Orthop Nurs 1996;15:56-65.
18. Melone CP. Joint injuries of the fingers and thumb. Emerg Clin North Am 1985;3:319-331.
19. Zook EG. Injuries of the fingernail. In: Green DP (ed). Operative Hand Surgery. New York, Churchill-Livingston; 1982:902.
20. Coleman DA. Metacarpal and phalangeal fractures. Top Emerg Med 1988;10:39-64.
21. Bennett EH. Fractures of the metacarpal bones. Dublin J Med Sc 1882;73:72-75.
22. Rolando S. Fracture de la base du premier metacarpien, et principalement sur une variete non encore decrite. Press med 1910;33:303.
23. Altman RS, Harris GD, Knuth CJ. Initial management of hand injuries in the emergency patient. Am J Emerg Med 1987;5: 400-404.
24. Lamon RP, Cicero JJ, Frascone RJ, et al. Open treatment of fingertip amputations. Ann Emerg Med 1983;12:358-360.
25. Burkhalter WE. Fingertip injuries. Emerg Clin N Am 1985;3:245-253.
26. Zook EG, Guy RG, Russell RC. A study of nail bed injuries: Causes, treatment, and prognosis. J Hand Surg 1984;9:247.
27. Hankin FM, Wylie RJ. Gamekeeper's thumb. Am Fam Phys 1988;38:127-130.
28. Louis DS, Huebner JJ Jr, Hankin FM. Rupture and displacement of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Preoperative diagnosis. J Bone Joint Surg 1986;68:1320-1326.
29. Bowers WH, Hurst LC. Gamekeeper's thumb. Evaluation by arthrography and stress roentgenography. J Bone Joint Surg 1977;59:519-524.
30. Smoot EC, Robson MC. Acute management of foreign body injuries of the hand. Ann Emerg Med 1983;12:434-437.
31. Galloway RE. Mammalian bites. J Emerg Med 1988;6:325-331.
32. Stewart CE. Mammalian bites. In: Stewart CE. Environmental Emergencies. Williams and Wilkins; Baltimore; 1990
33. Parks BJ, Horner RL, Trimble C. Emergency treatment of high pressure injection injuries of the hand. JACEP 1975;4:216-217.
34. Lewis RC. High compression injection injuries to the hand. Emerg Med Clin North Am 1985;3:373-381.
35. Kaufman HD. The clinicopathological correlation of high pressure injection injuries. Br J Surg 1968;55:214-218.
36. Curca PA, Chisholm CD. High-pressure water injection injury to the hand. Am J Emerg Med 1989;7:165-167.
Physician CME Questions
65. When examining the patient with a hand injury, radiographs should be obtained:
A. for penetrating injuries of the hand.
B. for simple dislocations of the finger.
C. when examining a hand infection.
D. in all but the most minor of hand lacerations or contusions.
66. Subungual hematomas should be drained:
A. when they are less than 25% of the surface of the nail.
B. when they are greater than 75% of the nail surface.
C. when they are associated with a transverse fracture of the nail.
D. when the nail has been avulsed.
67. A metacarpal neck fracture of the fifth metacarpal is often called:
A. a Bennet's fracture.
B. a Boxer's fracture.
C. a Tuft's fracture.
D. a Brewerton's fracture.
68. A devascularized digit should be:
A. immersed in ice water.
B. immersed in milk.
C. carefully cleaned of all debris and nonviable tissue.
D. placed in saline soaked gauze and put on ice.
69. Dislocation of the MCP) joint can cause:
A. an unstable joint.
B. a joint that requires surgical reduction.
C. rupture of the volar plate.
D. all of the above.
70. Froment's sign is useful in testing:
A. damage to the flexor carpi ulnaris.
B damage to the median nerve.
C. damage to ulnar nerve.
D. damage to the radial nerve.
71. Major clues to loss of sensation in the hand include:
A. flinch reaction to sharp/dull testing.
B. loss of capillary refill in the digit.
C. loss of sweating.
D. increased pain on flexion of the digit.
72. The median nerve supplies the:
A. web space between thumb and first finger.
B. the fifth finger.
C. dorsal surface of the proximal first and second fingers.
D. All of above.