Disorders of the Hand
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[edit] Disorders of the Hand
Joseph M. Lenehan
Approximately one third of all injuries involve the upper extremities.The National Safety Council estimated that 1.8 million disabling work injuries occurred in 1990, with 60,000 resulting in some permanent impairment.Upper extremity injuries accounted for 31% and hand injuries 24% of the cases.Thus these injuries represent a significant percentage of injuries seen by primary care physicians.Hand injuries cause not only significant physical disability but also deformities that are often a source of major psychologic trauma.
[edit] PATIENT EVALUATION
[edit] History
In addition to information regarding the patient's age, occupation, dominant hand, previous injury, and general health, a detailed history of the injury is needed.This should include the position of the fingers and hand at the time of injury, the degree of contamination, the initial treatment, and the interval between the injury and initial care.
[edit] Physical Examination
An understanding of functional anatomy is important in assessing the injured hand.Physical examination should be performed systematically to assess the skin, musculotendinous units, nerve and vascular supply, and bone and joint function.This is best accomplished by obtaining as much information by inspection as possible before asking the patient to actively move the hand, which may cause discomfort.Any gross positional deformity indicative of tendon or bone injury should be noted.The skin should be inspected for penetrating wounds or gross lacerations.An examination of the sensation in all digits, using the Weber two-point discrimination test, is important in determining median, ulnar, and radial nerve function (Fig.126-1).The vascular supply should be assessed by inspecting color and capillary filling.Once this information has been obtained, the musculotendinous units and motor function can be assessed.
[edit] Extrinsic Muscles.
The extrinsic muscles of the hand consist of the digital flexors and extensors; they should be tested individually.The flexor digitorum profundus tendons of the fingers are tested by stabilizing the proximal interphalangeal (PIP) joint of the fingers and asking the patient to flex the distal interphalangeal (DIP) joint actively (Fig.126-2).The flexor digitorum superficialis tendons of the fingers are tested by holding the adjacent fingers in full extension and asking the patient to flex the PIP joint of the involved digit (Fig.126-3).This effectively prevents the profundus tendon from acting on the digit being tested.The flexor pollicis longus tendon is tested by stabilizing the metacarpophalangeal (MCP) joint of the thumb and asking the patient to flex the interphalangeal (IP) joint (Fig.126-4).The extrinsic extensor muscles are first tested by passive motion at the level of the wrist to check for any gross positional deformities.Each extensor tendon is then tested individually for active function with the wrist held in theslightly extended position.The index and the little fingers have an additional tendon, the extensor indicis proprius and the extensor digiti minimi tendons, respectively.These can be tested by asking the patient to extend one digit alone while holding the others flexed.The extensor pollicis longus tendon is best tested by asking the patient to hold the hand flat on the table and then extend the thumb (Fig.126-5).The wrist extensors are tested by active extension against gravity with the fingers fully flexed in a fist with simultaneous palpation of the distal tendons.
[edit] Intrinsic Muscles.
Testing the intrinsic muscles requires a clear understanding of the motor supply from the median and ulnar nerves.The median nerve supplies the abductor pollicis brevis, opponens pollicis, and the superficial head of the flexor pollicis brevis muscles, which contribute to opposition of the thumb (Fig.126-6).The ulnar nerve supplies the interosseous muscles, the deep head of the flexor pollicis brevis muscle, the adductor pollicis muscle, and the hypothenar musculature.The lumbrical muscles to the index and long fingers are supplied by the median nerve and thoseto the ring and little fingers by the ulnar nerve.To test for thenar muscle function supplied by the motor branch of the median nerve, the patient must demonstrate opposition of the thumb, with the examiner palpating the thenar muscle group.Ulnar nerve motor function is tested (1) by observing the patient's ability to abduct and adduct the fingers and to flex the MCP joints with the IP joints in the extended position and (2) by checking the adequacy of the adductor pollicis muscle by assessing the power of a key pinch (Fig.126-7).
[edit] Sensory Testing.
A sensory examination should include mapping of the areas of diminished sensation that are revealed by light touch and use of the Weber two-point discrimination test (see Fig.126-1).Normal subjects can distinguish two points 6 mm apart.Besides assessing pallor and capillary filling, vascular examination should include palpation of pulses and an Allen's test at wrist and, if indicated, digital levels.This may be accompanied by a Doppler examination.
[edit] INJURIES
The patient with an acutely traumatized upper extremity should have a routine examination of all potentially involved structures.A sterile saline gauze dressing should be applied to the wound and the patient placed in the supine position with the hand elevated.Bleeding in the hand should be controlled by direct pressure alone; clamping a bleeding vessel is avoided because of its proximity to vital structures (e.g., nerves, tendons).The sterile saline gauze dressing should be left in place and the extremity assessed distal to the site of injury.A systematic examination can determine whether tendon, vascular, or nerve injuries exist.This is especially true for children, who often become uncooperative once the physician causes pain when examining the injury or exploring the wound.
[edit] Tendons
Tendon injuries can occur with small, superficial-appearing wounds if the tendon is under tension at the time of injury.This is most evident with superficial lacerations over the flexor creases of the fingers or wrist, which often result in significant nerve and tendon injuries.
[edit] Flexor Tendons.
The flexor creases have no subcutaneous fat at the IP joint level, and a small puncture wound to that area often results in an injury to the flexor sheath.The patient with a partial tendon injury may not have a gross positional deformity but may complain of pain when flexing the finger actively.Testing finger flexion against resistance may elicit pain if there is a partial tendon injury; such testing must be done with caution, however, because it may cause a partial tendon transection to rupture.Critical areas include the flexor digitorum profundus tendon distal to the superficialis tendon insertion and distal to the flexor crease at the PIP joint.The transection of the flexor pollicis longus tendon at the level of the flexor crease at the MCP joint is also a common injury.In examining for flexor tendon injuries, the flexor digitorum superficialis and profundus tendons should be tested independently (see Figs.126-2 and 126-3).Examination of the flexor pollicis longus tendon requires demonstration of active flexion at the IP joint (see Fig.126-4).Many patients do not have significant independent flexion at the PIP joint of the little finger.The superficial tendon of the opposite little finger should be tested (Fig.126-8).A closed rupture of the flexor digitorum profundus tendon can occur.Usually it involves the ring finger in a sports-related grasping injury.If this injury is recognized early, the tendon can be reinserted on the distal phalanx.
[edit] Extensor Tendons.
Extensor tendon injuries occur with the fingers fully flexed or extended.Thus all dorsal wounds should be explored for tendon injuries.The fingers should be flexed and then extended so that the tendon can be examined through the full range of its excursion.The two tendons to the index and little fingers, which allow for independent extension of these digits, must be identified.When examining dorsal wounds for possible extensor tendon injuries, the physician must recognize the role of the juncturae tendinum, which are communications between the common digital extensor tendons on the dorsum of the hand (Fig.126-9).Lacerations over the dorsum of the MCP joint area usually result in a lack of MCP extension, provided the transection is distal to the juncturae tendinum.IP joint extension results from intrinsic muscle function and MCP joint extension from extrinsic tendon function.In the absence of the extrinsic tendons the IP joints can be completely extended.Any laceration over the MCP joint should suggest a human bite wound.
[edit] Nerves
When assessing lacerations of the hand, the physician should understand the anatomic characteristics of the nerves potentially involved (Fig.126-10).The proper digital nerves on the volar aspect of the thumb are immediately adjacent to the flexor pollicis longus tendon sheath near the MCP jointand are susceptible to injury.The radial and ulnar proper digital nerves at this point are approximately 1 to 1.5 cm apart.The dorsal sensory branch of the ulnar nerve and the superficial radial nerve with its multiple branches pass in the subcutaneous tissue over the dorsal ulnar and dorsal radial aspect of the wrists, respectively.They are easily palpated and susceptible to injury by relatively superficial lacerations.On the volar aspect of the fingers the proper digital nerves are volar to the digital arteries.A patient presenting with a volar finger laceration and arterial bleeding most likely has a transected digital nerve in addition to the transected artery.A digital sensory examination using a paper clip should be performed to determine two-point discrimination before any anesthesia is instilled.In addition, if regional block anesthesia is performed, motor muscle testing of the intrinsic musculature should be done first.Regional nerve blocks include the intermetacarpal block and, at the wrist, the superficial radial nerve, dorsal sensory branch of the ulnar nerve, the median nerve, and the ulnar nerve blocks.With the widely used techniques of magnification for nerve repairs, a proper digital nerve can be repaired at the level of the DIP joint.The timing of nerve repair is controversial, but for sharp, clean wounds with nerve injury, primary repair is usually indicated.
[edit] Radiographic Examination
X-ray examination of the hand or finger is needed for most hand injuries and for lacerations resulting from glass; however, wood and nonopaque glass often are not demonstrated radiographically.In addition to searching for foreign bodies, a radiograph should be obtained to assess the hand for fractures, puncture wounds of the bone, dislocations, and ligamentous injuries with small avulsion fragments.Additional x-ray studies can provide true lateral views of the PIP joint for assessment of intraarticular fractures or dislocations and oblique views of the ring and little metacarpals for assessment of fractures or dislocations of the carpometacarpal joints.Once a nerve, tendon, joint, or open fracture is confirmed, further exploration of the wound is not indicated.The injury requires surgical exploration and repair in the operating room.Local exploration of the wound only increases the risk of contamination and may cause a blood clot to be dislodged, resulting in bleeding and requiring emergency interventions.
[edit] Diagnostic Considerations
In the hand, vital structures lie immediately beneath a thin covering of skin, especially over the joint surfaces on the dorsum and over the flexor creases on the volar aspect.In open injuries it is important to recognize a partial flexor or extensor tendon laceration, a transection of the flexor digitorum profundus tendon distal to the superficialis insertion (see Fig.126-8), a transection of the common digital extensor tendon without extension lag because of the junctura tendons (see Fig.126-9), digital nerve injuries, and crush injuries to the fingertip with subungual hematoma and nail bed injuries.
In closed injuries, long-term morbidity can result from mallet deformity at the DIP joint, boutonnière deformity at the PIP joint, collateral ligament injuries at the MCP joint of the fingers and thumb and PIP joint of the fingers, and rupture of the flexor digitorum profundus tendon from its insertion.Minor hand injuries must be properly splinted to allowuncomplicated wound healing in areas over mobile joint surfaces.
[edit] SPECIFIC DISORDERS AND TREATMENTS
[edit] Fractures
Basic orthopedic principles for the treatment of fractures apply to the hand, with the understanding that accurate reduction is required to restore maximum function to small hand bones and joints.Stable fractures usually can be treated by closed reduction and splinting.Unstable and displaced intraarticular fractures often need open reduction with internal fixation.Fractures are classified as either open or closed; an open fracture communicates with the wound.
[edit] Rotational Deformities.
Gross angular or rotational deformity may allow easy recognition of a bone or joint injury.Palpation for tenderness at the injury site can be performed before x-ray examination.Motion or stress examination is usually reserved until after adequate radiographic assessment, which often includes anterior and true lateral views.Careful examination is required to evaluate for rotational deformities.Flexed fingertips normally point toward the scaphoid (Fig.126-11).Overlapping or malpositioning of the fingertips should be observed in both flexed and extended positions.In the extended position, rotation is assessed by noting the relationships of the curve of the fingernails with the adjacent fingers and comparing this with the opposite hand.
[edit] Radiographic Examination.
X-ray films may be misleading because overlapping structures can obscure a small fragment of bone.In hand injuries, small fragments of bone are often attached to a collateral ligament, a volar plate, or a displaced tendon (Fig.126-12).The fragment may signify a potentially unstable condition that must be treated to avoid deformity.Particular attention should be directed to intraarticular fractures.In the case of specific ligamentous injuries, x-rays should be obtained before testing for instability (e.g., MCP joint of thumb).Stress testing may displace a previously undisplaced intraarticular fracture that could have been treated by immobilization alone.
[edit] Terminal Phalanx.
Fractures of the terminal phalanx are usually the result of crush injuries and are associated with subungual hematomas and nail bed injuries.In most cases the subungual hematoma should be evacuated; if nail bed injuries exist, the nail should be removed and the laceration of the nail bed repaired with fine absorbable sutures.Adequate repair of the nail bed in soft tissue injuries usually results in a satisfactory reduction of the fracture fragments.Occasionally, with more proximal terminal phalanx fractures, open reduction and internal fixation are indicated.If there is a concomitant flexion deformity at the DIP joint, a tendon injury may exist in addition to the fracture.
[edit] Middle and Proximal Phalanx.
Fractures of the middle and proximal phalanx can be displaced by a number of forces.Because of the extrinsic flexor and extensor tendons' longitudinal pull and the potential for rotational deformities, these fractures must be assessed for both rotational and angulation deformities (see Fig.126-11).Furthermore, intraarticular fractures at the PIP and DIP joints may produce unstable fragments involving the articular surface (see Fig.126-12).These fractures may be complicated by subluxation or fracture dislocation, requiring open reduction and internal fixation.Small fractures involving one fourth of the articular surface on the volar lip of the middle phalanx may be associated with late dorsal dislocation.Intraarticular injuries with small fragments, even if not displaced, have a potential for significant morbidity.
[edit] Metacarpal.
Fractures of the metacarpal are usually treated by closed reduction.These fractures must be assessed for overriding with shortening and angulation.Rotational alignment is critical in metacarpal fractures and is checked by observing position of the fingernails and alignment of thefingertips (see Fig.126-11).Postreduction rotation should be checked clinically and radiographically.With open injuries and multiple displaced fractures, internal fixation is often recommended.
Bennett's fracture is an oblique intraarticular fracture through the base of the thumb (Fig.126-13).The metacarpal shaft, the larger segment, is displaced proximally by the pull of the thumb's long abductor tendon.The volar ulnar fragment of the metacarpal usually remains in its normal position because of ligamentous attachments; it requires reduction and often internal fixation.A similar intraarticular fracture or fracture dislocation can occur at the base of the fifth metacarpal, involving the carpometacarpal joint.This fracture also requires reduction and frequently internal fixation.
[edit] Scaphoid.
Fracture of the scaphoid usually results from a fall on an outstretched hand.The patient presents with pain and tenderness elicited by palpation in the anatomic snuff-box (Fig.126-14).Fracture of the scaphoid is the most common fracture of the carpal bones and the upper extremity fracture most often undiagnosed.When a scaphoid injury is suspected, the wrist should be immobilized despite a negative radiograph and treated for presumed scaphoid fracture.X-ray examination should be repeated in 2 weeks, when a fracture may be visualized.
[edit] Dislocations
Dislocations in the hand occur primarily at the IP and MCP joint levels.At the IP level, fractures result from hyperextension force or direct trauma on the fingertip and may produce a burst wound along the flexor crease at the DIP or PIP joint.Closed injuries often can be reduced without difficulty and splinted in slight flexion at the IP joint level.MCP joint dislocation usually results from a hyperextension injury.The volar plate is usually disrupted proximally at its metacarpal attachment, and the joint is dislocated so that the proximal phalanx lies dorsal to the metacarpal head.The metacarpal head can become trapped through a buttonhole of tissue and usually cannot be reduced by closed technique.The thumb MCP joint often can be reduced closed, but it occasionally requires open reduction.The most common dislocation of the carpals is a volar dislocation of the lunate, which may be associated with acute median nerve compression, requiring immediate reduction.If the physician is not familiar with techniques of reduction, the patient should be referred.
[edit] Ligamentous Injury
Injury to the ulnar collateral ligament at the MCP joint of the thumb usually results from acute radial deviation of the thumb at the MCP joint (Fig.126-15).This injury usually is caused by a skiing fall and results in a complete or incomplete tear of the ulnar collateral ligament.The patient presents with swelling, pain, and tenderness on the ulnar side of the thumb's MCP joint.The area should be examined radiographically, and if no fracture is found, stress testing is recommended.With an incomplete lesion and minimal deviation on stress testing, immobilization with a thumb spica cast may be satisfactory.Significant laxity associated with completedisruption of the ulnar collateral ligament requires surgical repair of the ligament.
[edit] Mallet Finger
Mallet finger is a flexion deformity of the fingertip at the DIP joint secondary to avulsion of the extensor tendon from its insertion on the dorsal surface of the distal phalanx (Fig.126-16).The patient presents with absent or incomplete active extension at the DIP joint.The mechanism of injury is often direct trauma to the fingertip, resulting in an avulsion of the extensor tendon.Treatment of a closed injury with a tendon avulsion or a tendon avulsion with a small fragment consists of splinting the DIP joint in the neutral position for 6 weeks and night splinting for an additional 2 or more weeks.When a larger fragment representing one third or more of the articular surface is present, or when a fragment is associated with volar subluxation of the terminal phalanx, open reduction and internal fixation are indicated.Radiographic assessment requires a true lateral view of the DIP joint.
[edit] Boutonnière Deformity
Boutonnière deformity is a flexion deformity of the finger at the PIP joint with hyperextension of the DIP joint (Fig.126-17).This injury results from a rupture or laceration of the central slip of the extensor mechanism at or near its insertion into the base of the middle phalanx.The lateral bands of the extensor mechanism progressively dislocate in a volar direction from tearing or stretching of the transverse retinacular ligament, which normally maintains the position of the lateral bands dorsal to the axis of the PIP joint.As thelateral bands slip volar to the axis of the PIP joint, a flexion deformity of the PIP joint is created; shortening of the lateral bands results in a hyperextension deformity at the DIP joint.This deformity often is not present at the time of injury but develops slowly over weeks as the lateral bands drift progressively in a volar direction.If the injury is caused by an open wound, the central slip should be surgically repaired.The deformity is often seen late, and late closed injuries should be treated by splinting the PIP joint in extension and allowing active flexion at the DIP joint to stretch the shortened lateral bands.This injury requires a prolonged period of carefully supervised splinting.
[edit] Swan-neck Deformity
In a swan-neck deformity of the finger the PIP joint is in hyperextension and the DIP joint is in flexion.This condition can be caused by traumatic injury to the volar plate, a previous mallet finger deformity, rheumatoid arthritis, or intrinsic contraction.
[edit] Dupuytren's Contracture
Dupuytren's contracture results from a proliferative fibroplasia of the longitudinal band of the palmar aponeurosis that forms in nodules and cords (Fig.126-18).The area involved is between the skin and the flexor tendon in the distal palm and fingers and can produce contractures at the metacarpal and PIP joints.The flexor tendons are not involved.The cause of this disorder is unknown, although heredity is a factor.The most common areas affected are the ring and little fingers, with occasional involvement of the thumb and long fingers.The condition may be associated with thickened knuckle pads over the PIP joint of the fingers and involvement of the plantar fascia.Surgical intervention is not recommended until definite flexion contracture develops at the metacarpal or PIP joints.
[edit] Trigger Finger and Thumb
Trigger finger and thumb may be congenital, occurring in infancy, but usually develops in adulthood from a nonspecific tenosynovitis of the flexor tendon sheath.The inflammation at the level of the proximal pulley of the flexor sheath produces a stenosis of the sheath, termed stenosing tenosynovitis. This causes telescoping of the fibers of the flexor tendon and results in a discrepancy between the size of the tendon and the opening at the level of the proximal pulley.The patient presents with a locking or snapping of the finger or thumb, with point tenderness and a nodule over the base of the flexor sheath near the MCP joint.The finger may be locked in the flexed or extended position.If the condition is chronic, referral for steroid injection or surgical treatment is often required.
[edit] Bowler's Thumb
Bowler's thumb is an injury to the ulnar proper digital nerve of the thumb at the level of the MCP joint secondary to repetitive trauma while grasping a bowling ball or heavytools.Repetitive trauma can lead to perineural fibrosis.The patient presents with a tender mass on the ulnar aspect of the thumb just distal to the metacarpal joint, which usually represents a swelling of the nerve, with decreased sensation on the ulnar tip of the thumb.With early presentation, avoidance of the repetitive trauma usually allows the condition to resolve.
[edit] De Quervain's Stenosing Tenosynovitis
De Quervain's stenosing tenosynovitis is a nonspecific inflammatory condition involving the abductor and extensor pollicis tendons at the level of the first dorsal compartment.The condition usually affects women 30 to 50 years of age, who present with pain and tenderness, with palpable thickening in the first dorsal area.Finkelstein's test may be positive (Fig.126-19).De Quervain's tenosynovitis must be differentiated from a bony pathologic condition of the distal radius or carpus and from carpal metacarpal joint degenerative arthritis.Recommended early treatment consists of splint immobilization and antiinflammatory medications.Chronic conditions may require referral for steroid injection or surgical intervention.
[edit] Carpal Tunnel Syndrome
Carpal tunnel syndrome is a median nerve compressive neuropathy that occurs at the level of the wrist where the median nerve passes deep to the transverse carpal ligament.The condition usually affects women 30 to 60 years of age.The patient complains of numbness in the median nerve distribution, which may be exacerbated at night and is associated with some pain on the volar aspect of the forearm.The patient also may note tingling in the thumb, index, and long fingers and may tend to drop small objects.The condition usually involves the dominant hand but can be bilateral.Carpal tunnel syndrome may be associated with trauma (e.g., Colles' fracture), repetitive activity, edema secondary to trauma or infection, space-occupying lesions (e.g., lymphoma, ganglion), or systemic medical conditions (e.g., diabetes mellitus, thyroid dysfunction, amyloidosis, pregnancy).Often the cause is nonspecific but accompanies inflammatory conditions and rheumatoid tenosynovitis.
On examination the patient may have slight atrophic changes of the fingertips in the median distribution and atrophy of the thenar muscles, particularly the abductor pollicis brevis.Sensory testing may indicate abnormal two-point discrimination.Tinel's sign, the production of paresthesias in the hand by tapping over the median nerve at the level of the wrist or carpal tunnel, is often present with carpal tunnel syndrome (Fig.126-20).When a degree of compressive neuropathy exists, Phalen's test, flexing of the wrist for 1 minute, causes increased paresthesias in the median nerve distribution resulting from increased pressure within the carpal tunnel.Symptoms may improve with a volar carpal splint and antiinflammatory medications.Otherwise the patient should be referred for consideration of steroid injection of the carpal tunnel or surgical release.
[edit] Arthritis
The major forms of arthritis that affect the hand are osteoarthritis and rheumatoid arthritis (see Chapters 132 , 133 to 134 ).Osteoarthritis involves the IP joints and the carpometacarpal joint of the thumb and often presents with swelling, stiffness, pain, and deformity.At the DIP joints, osteophytes may be associated with mucous cyst formation dorsally over the joint or in the eponychium.Rheumatoid arthritis affects the MCP and PIP joints and presents with pain, swelling, and stiffness.The condition may progress to deformity.
[edit] Tumors
[edit] Ganglions.
Ganglions are the most common soft tissue tumor of the hand.These cystic masses arise from the tendon sheath or joint and may be related to acute trauma or recurrent chronic injury.The most common location is on the dorsum of the wrist over the radiocarpal joint in the area of the scapholunate ligament.Other locations include the volar surface of the wrist near the flexor carpi radialis tendon and the flexor sheaths of the fingers.Ganglions may present as an asymptomatic mass or may be associated with aching, pain, and weakness.They may disappear spontaneously.Persistent symptomatic ganglions may be referred for aspiration or removed completely through surgical intervention.
[edit] Lipomas.
Unusual soft tissue tumors of the hand, lipomas present as a soft, asymptomatic mass.They may be deceptively large, extending deep beneath the fascia of the hand.
[edit] Giant Cell Tumors of Tendon Sheath.
The second most common tumor in the hand, giant cell tumors of tendon sheath can occur at any age and are more common in women.They usually present as a painless, slow-growing mass on the volar or dorsal aspect of the finger.Giant cell tumors havebeen associated with repetitive trauma.These benign lesions may enter joint spaces and create extrinsic pressure defects on the bone.They should be distinguished from giant cell tumors of the bone, which are malignant lesions.
[edit] Inclusion Cysts.
Inclusion cysts of the digits result from penetrating trauma with implantation of epidermal elements beneath the skin.These painless cystic masses usually occur in the palm or on the volar aspect of the finger.
[edit] Glomus Tumor.
An abnormal growth from an arteriovenous anastomosis normally present in the digits, glomus tumor usually occurs in the nail beds and fingertips.Patients often complain of severe pain exacerbated by exposure to cold.Alteration in color of the nail bed may be associated with point tenderness over the area of the lesion.The lesion is often less than 1 cm in diameter.If large enough, glomus tumor may erode the bone of the terminal phalanx, as demonstrated radiographically.
[edit] Bone Tumors.
Usually benign, bone tumors are most often an enchondroma, or cartilaginous growth.They may present with posttraumatic pain and a pathologic fracture or may be discovered as an incidental finding on x-ray examination.
[edit] Infections
Infections can result in significant morbidity and functional loss; they are usually caused by a minor injury such as an abrasion.A significant infection can result in edema, tissue necrosis, and fibrosis and contracture.Antibiotics have significantly decreased the rate of mortality from hand infections but have not eliminated the need for incision and drainage.The timing and technique of surgical drainage are important in minimizing the degree of morbidity with infections.
The majority of hand infections are caused by coagulase-positive Staphylococcus aureus and Streptococcus. Infections caused by staphylococci often require incision and drainage.Streptococcal infections usually present as cellulitis with lymphangitis and lymphadenopathy.Human bite infections, common in the hand, often present with an injury over the MCP joint and sometimes with septic arthritis.The onset of symptoms resulting from the injury is rapid; classic signs of joint involvement include pain on passive range of motion at the MCP joint and point tenderness over the joint's volar aspect.The pathogenic organisms include anaerobic mouth organisms in addition to S.aureus and Streptococcus. An injury suggestive of a human bite infection with involvement of the MCP joint requires surgical exploration.In certain anatomic spaces the organisms may develop a localized abscess, requiring surgical incision and drainage.
[edit] Paronychia.
An infection of the soft tissue around the fingernail, paronychia usually begins as a hangnail (Fig.126-21).The most common organism is S.aureus, with the portal of entry being the eponychium.Paronychia may involve one corner of the nail or extend to the opposite side under the eponychium or fingernail.The patient presents with pain, erythema, and tenderness in the area of the eponychium or paronychium.Incision and drainage are indicated when a localized purulent collection is present.This may requireremoving a portion of the nail to obtain adequate drainage.Chronic recurrent paronychia should suggest a fungal infection.
[edit] Herpetic Whitlow.
Herpes infection can involve the fingertip (herpetic whitlow) and may resemble a bacterial paronychia.The distinction is important because incision does not help and may delay healing.Herpetic whitlow is a viral infection, and medical and dental personnel are at particular risk.Usual symptoms include pain or pruritus followed by the formation of vesicles, which may coalesce.The pain may become intense and is occasionally accompanied by bacterial infection.Healing usually takes 2 to 3 weeks.Therapy includes analgesia, saline soaks, and local wound care.
[edit] Felon.
A felon is a digital pulp space abscess (Fig.126-22).It usually causes significant throbbing pain, which develops over 48 to 72 hours.The fingertip is extensively involved and may become necrotic from ischemia.Interference with the blood supply to the diaphysis of the terminal phalanx may also result in aseptic necrosis.The bone can become secondarily infected, and osteomyelitis may develop.Treatment consists of incision and drainage after adequate anesthesia.In making the incision, the physician must avoid the digital nerves and not create painful scars on the contact points of the digit's volar pad.
[edit] Deep Space Infections.
The deep palmar space lies between the fascia covering the metacarpals and the fascia below the flexor tendon sheaths on the volar aspect of the palm (Fig.126-23).This space is divided into the thenar and midpalmar spaces by a septum that passes from the fascia beneath the index flexor sheath dorsally to the third metacarpal shaft.The adductor muscle of the thumb rises from the entire length of the third metacarpal bone and inserts in the thumb in the area of the MCP joint.This muscle divides the thenar space into anterior and posterior divisions.Both deep space infections cause systemic signs as well as local pain, tenderness, and decreased active range of motion of the fingers.A thenar space abscess causes tenderness over the thenar half of the palm and marked swelling of the thumb-index web space, which requires drainage.A midpalmar space abscess causes tenderness and swelling over the palm on the ulnar aspect with decreased range of motion of the middle, ring, and little fingers (Fig.126-24).This space is drained through a transverse incision at the level of the distal palmar crease.
[edit] Tenosynovitis.
Acute or purulent tenosynovitis is an infection of the flexor sheath that usually results from a penetrating wound over a flexor crease of the finger or palm.The patient usually presents with rapidly developing signs of infection (Fig.126-25).The four signs of flexor sheath infection are uniform swelling of the digit, slight flexion of the involved finger, tenderness over the length of the involved flexor tendon sheath, and increased pain on passive extension of the finger.The patient cannot actively flex the finger and experiences pain in the attempt.
Acute purulent tenosynovitis is a closed-space infection and often requires incision and drainage.The flexor sheath of the thumb extends from the tip of the thumb proximally through the carpal canal into the radial bursa on the distal forearm.The flexor sheath of the little finger extends from the tip of the little finger throughout the carpal canal into the ulnar bursa on the distal forearm.The flexor sheaths on the index, long, and ring fingers extend to the level of the proximal palmar crease (see Fig.126-23).Surgical drainageusually requires an incision in the palm and in the affected digit and, in the case of the thumb and little finger, possibly at the level of the distal forearm.
[edit] Interventions.
The general principles for treatment of hand infections are immobilization; incision and drainage when indicated; elevation of the infected part; systemic antibiotics; placement of the wrist, hand, and fingers in the position of function; and treatment of systemic diseases that can be exacerbated by the infection.Surgical intervention for closed-space infections of the hand should be carried out in a bloodless field under adequate anesthesia.Significant infection with associated edema may result in fibrosis and contracture of the affected area despite long-term therapy.
The removal of rings from a swollen finger is important.Rings usually can be removed with a soapy solution.Other techniques include using a ring cutter or the spiral string technique (Fig.126-26).
Removing fishhooks can be accomplished after adequate anesthesia by either pushing the tip through and cutting it off or trying to pass the bevel of a needle over the barb and removing the needle in a retrograde manner (Fig.126-27).
[edit] ADDITIONAL READINGS
- American Society for Surgery of the Hand:The hand: examination and diagnosis. New York: Churchill Livingstone; 1990:
- American Society for Surgery of the Hand: The hand: primary care of common problems,. New York: Churchill Livingstone; 1992:
- American Society for Surgery of the Hand: Hand surgery update,. Rosemont, Ill: American Academy of Orthopaedic Surgeons; 1996:
- Green DP: Green's operative hand surgery. ed 4. New York: Churchill Livingstone; 1999:
- Jupiter JB: Flynn's hand surgery. Baltimore: Williams & Wilkins; 1991:
- Lucas GL: Examination of the hand. Springfield, Ill: Thomas; 1972:
- Milford L: The hand. St Louis: Mosby; 1982:
- Zenz C: Occupational medicine. St Louis: Mosby; 1994:
