24. | Manual of Rheumatology and Outpatient Orthopedic Disorders (LB Spiral Manuals)

Chapter 17 Hand Disorders

Manual of Rheumatology and Outpatient Orthopedic Disorders

Chapter 17 Hand Disorders

Robert L. Merkow and Paul Pellicci

Anatomy and function
History
Physical examination
Diagnostic studies
Inflammatory conditions
Injuries of the fingers
Arthritic conditions
Tumor and swelling
Hand deformities
Abnormalities of sensation

Disorders of the hand are common; the primary physician is frequently called on to evaluate, diagnose, treat, or refer these important problems. The diagnosis of hand disorders can usually be made by appropriate history, physical examination, radiographs, and laboratory data. A knowledge of basic functional anatomy and physiology, together with a systematic approach to examination, will enable the practitioner to arrive at a working diagnosis and plan a rational therapeutic regimen.

I. Anatomy and function. Sir Charles Bell, the leading British anatomist, physiologist, and neurologist of the early nineteenth century, was among the first to recognize the unique qualities of the human hand: It is in the human hand that we perceive the consummation of all; perfection , as an instrument. This superiority consists in its combination of strength, with variety, extent, and rapidity of motion . . . and the sensibility, which adapt it for holding, pulling, spinning, weaving, and constructing; . . . with the hands, the laborer supports a family, the parent loves and cares for a baby, the musician plays a sonata, the blind ˜read' and the deaf ˜talk.' ¹ The hand is an essential, complex organ comprising many specialized tissues. The hand-wrist unit integrates 27 bones and joints and 36 intrinsic and extrinsic muscles innervated by branches of three major nerves. The hand is supplied by two blood vessels and contains a variety of highly specialized retinacula and cutaneous structures.

A detailed description of hand anatomy and dynamics of function is beyond the scope of this chapter; however, certain generalities deserve emphasis, for they relate directly to the discussion of common hand disorders.

The bones of the hand are divided into three groups: the carpal bones, metacarpal bones, and phalanges. These are functionally grouped into fixed and mobile units. The hand is not flat but rather is shaped with structurally and functionally important transverse and longitudinal arches.
The fixed unit of the hand is central and consists of the index and long-finger metacarpals and the slightly mobile capitate, trapezium, and trapezoid bones, which form the bony keystone foundation of the hand. The flanking mobile units consist of the strong, mobile thumb on the radial side and the powerful ring and little finger on the ulnar side.
The muscles and tendons are divided into two groups: the intrinsic muscles (arising from within the hand) and the extrinsic muscles (arising from the forearm and elbow , but inserting into the hand via long tendons). The extrinsic muscles consist of the long flexors and extensors and provide movement and power to the fingers and thumb. The intrinsic muscles are grouped into the thenar and hypothenar muscles, the lumbricals, and the volar and dorsal interosseous muscles. These provide a strong thumb and a fine balance of flexor-extensor mechanisms for the precise and coordinated motions of the fingers.
The three major nerves supplying the hand are the median, ulnar, and radial nerves. The hand has an enormous share of sensory and motor representation in the brain. It should be appreciated that all purposeful hand function is initiated in the cerebral cortex .
1. The radial nerve innervates the extensor muscles in the forearm and provides dorsal sensation to the thumb, first web space, index finger, long finger, and radial half of the ring finger to the level of the proximal interphalangeal (PIP) joint.
2. The median nerve supplies all motor branches in the volar forearm except to the flexor carpi ulnaris (FCU) and the flexor digitorum profundus to the ring and little finger (FDP4+5). The median nerve enters the forearm through the two heads of the pronator teres at the elbow; it courses down the forearm volarly within the deep fascia of the flexor digitorum superficialis (FDS) muscle group . The median nerve enters the hand superficially at the wrist through the carpal canal. It also innervates the thenar muscles, except the adductor (via the recurrent motor branch at the base of the thumb), and supplies the lumbricals to the index and long fingers. The median nerve provides important sensation to the thumb, the index and long fingers, and radial half of the ring finger.
3. The ulnar nerve supplies only the FCU and FDP4+5 in the forearm. It runs deep to the FCU, entering the hand via the canal of Guyon between the pisiform and the hook of the hamate bone. In the hand, the ulnar nerve supplies the hypothenar muscles and the remaining intrinsic muscles, and its sensory branches innervate the little finger and the ulnar half of the ring finger.
The blood and lymphatic vessels supply the hand with two major branches of the brachial artery: the radial and ulnar arteries entering the hand at the wrist. These anastomose in the palm, forming superficial and deep arches that give off arterial branches to the thumb and fingers. The venous and lymphatic networks run from the palmar to the dorsal side of the hand (this, together with the loose dorsal skin, accounts for the prominent dorsal swelling that can occur in the hand and fingers). The dorsal veins coalesce into the cephalic (radial side) and basilic (ulnar side) systems.

II. History. Because hand function is integral to all activities of daily living, the patient will usually be able to describe accurately the duration and degree of disability.

The general history should include the following:
1. The patient's age, occupation , hand dominance , and previous impairment .
2. Activities and hobbies.
3. Medical history, including any underlying systemic disorders, such as diabetes, vascular disease, and endocrine or collagen vascular disorders.
4. The distinction between traumatic and nontraumatic causes is useful; however, disorders may occur concomitantly or be noted after an unrelated injury .
The specific history regarding dysfunction of the hand should include duration of disability, precipitating causes, and specific loss of function. Cardinal symptoms include pain, swelling, deformity, and alteration in sensation or strength.
1. Type and severity of pain, as well as location and pattern, are important. What is its onset and progression? Is it constant or intermittent? Does it occur at night? Which specific acts make the pain worse ? Is the pain well localized, or does it radiate in a nerve or root distribution? Pain in the neck or other joints may also be helpful in determining a remote or systemic cause. Finally, what treatments or medication have been tried, and what have been the results?
2. Swelling and deformity may be subjective . They may be subtle or obvious. Inquiries regarding onset, progression, and response to treatment should be made.
3. Numbness, weakness, and paresthesia may indicate neurologic dysfunction. The severity, anatomic distribution, duration, and progression of the symptoms are important. Identifying precipitating activities or positions can be very helpful in localizing neurocompressive problems. A history of neck pain or radiation should also be sought.

III. Physical examination. The patient should be sitting, and the entire upper extremity should be exposed and evaluated.

Surrounding joints. Begin at the neck; check range of motion, and palpate for areas of tenderness.
1. The shoulder and elbow should be fully examined because either may be the source of a hand disorder . Assessment of active motion at the shoulder and elbow as well as of forearm pronation and supination is important because motion at these joints is necessary for proper positioning of the hand for function. Note any discrepancy between active and passive motion. Closely examine the shoulder, arm, and forearm for evidence of muscle atrophy.
2. Wrist. Evaluate both active and passive range of motion, including supination and pronation. Compare right and left sides. Observe and palpate for localized swelling or tenderness. Note whether areas of swelling appear to arise from the carpal joints per se, from the distal radioulnar joint, or from the more superficial dorsal tendons crossing the wrist (in the last case, the swelling may move with digital flexion-extension).
Hand. Observe the resting posture of the hand, and record specific areas of muscle atrophy, discoloration, abnormal swelling, or deformity. Comparison with the contralateral hand (if normal) can be helpful. Accurate recording of the findings is important; a simple sketch of the hand with appropriate notations and measurements is often helpful.
1. The attitude or position of the hand should be inspected for loss of the normal transverse and longitudinal arches, loss of the flexion cascade of the fingers, abnormal posturing, or deformities of the fingers and thumb.
2. Circulation is assessed by observing the color of the skin and fingernails as well as blanching and flush of the nail bed. Patency of the radial and ulnar arteries can be assessed by use of Allen's test. This test can also be applied to the digital vessels.
3. Skin is normally thick and moist on the palmar surface and thin and mobile on the dorsal surface. Examine for the presence or absence of swelling, wrinkles , moisture, scars, or cutaneous lesions.
4. Joints should be inspected for evidence of effusion, synovitis, osteophytes, or loss of normal alignment and motion.
5. Motions of the hand as a unit and individual joints should be checked for stiffness or abnormal mobility. Have the patient make a fist and fully extend the fingers. Evaluate and record action range of motion at the metacarpophalangeal (MCP), PIP, and distal interphalangeal (DIP) joints. Gently check passive flexion and extension of the finger joints and record any fixed contractures.
6. Flexor tendon function is evaluated by asking the patient to flex at the DIP joints while holding the MCP and PIP joints in extension. This action evaluates the FDP function. To test the FDS function, hold the other fingers in extension at the MCP, PIP, and DIP joints, and allow free the digit to be tested . Flexion should occur at the PIP joint, and the DIP joint should be flaccid.
7. Sensation is best tested for light touch with cotton and for two-point discrimination with the prongs of a paper clip. Measure the distance at which the distinction between one and two points is not accurate, and compare with the other digits and contralateral hand. Normally, a patient can distinguish two points 6 mm apart on the pulp of the fingers.
8. Grip and pinch strengths are useful objective measurements and should be recorded and compared with the contralateral side.
9. Simple functional tasks . The patient's ability to use the hand for activities of daily living should also be evaluated and recorded.

IV. Diagnostic studies

Radiographs should include anteroposterior, lateral, and oblique views of the hand and wrist. Additional cone-down views of an involved digit are often needed to look at specific bones and joints.
Nerve conduction and electromyographic studies should be obtained if there is evidence of nerve dysfunction (i.e., significant weakness, atrophy, or sensory abnormality). These studies supplement the clinical history and examination in documenting neurologic dysfunction and evaluating the anatomic location and extent of the process.
Joint aspiration should be performed when significant effusion is present (see Chapter 4 and Chapter 5). Synovial fluid is examined grossly and sent for cell counts and crystal, biochemical, and microbiologic studies.

V. Inflammatory conditions are common and may be caused by infections, sterile synovitis, tendinitis, or tenosynovitis, sometimes with calcifications. (Specific arthritic conditions are discussed in section VII. )

Stenosing tenosynovitis is the cause of trigger finger or thumb and de Quervain's disease of the thumb extensors. It is commonly encountered in patients with a history of repetitive manual trauma. The process is caused by tenosynovitis of the tendon, sheath, or synovium with a nodule-like enlargement of the tendons. These may catch on the pulley entrance to cause locking or triggering.
1. In trigger finger or thumb, digital motion is restricted when the tendon lesion impinges on the unyielding pulley at the base of the finger. The patient will describe a painful locking of the finger in flexion. Extension is often possible only by using the contralateral hand to extend (unlock) the finger forcefully , and this is accompanied by moderate pain. The patient will frequently describe this process as worse in the morning (because of swelling) and loosening up as the day progresses.
  1. Physical examination demonstrates a tender, palpable nodularity in the palm that moves with the flexor tendon and may catch with passive motion. The best way to demonstrate the locking phenomenon is to have the patient fully flex all fingers actively and then slowly extend; the locking fingers will either remain locked or will snap open on extension.
  2. Treatment
    1. Injection with 4 mg (1 mL) of aqueous dexamethasone (Decadron) and lidocaine into the inflamed tendon sheath may diminish the inflammatory process and swelling and allow for normal motion in approximately 50% of cases. Unfortunately, in a large proportion of cases, recurrence will be noted after several months.
    2. Surgical release of the tight pulley (and a limited tenosynovectomy, when needed) is indicated for severe cases with painful locking or when conservative treatment fails. This provides safe and effective resolution of symptoms.
2. De Quervain's stenosing tenosynovitis is similar in pathogenesis to trigger finger. Pain is the cardinal symptom, and it is located in the area of the anatomic snuffbox at the dorsoradial aspect of the wrist. Inflammation of the tendons and sheaths of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) may result from repetitive movements of the thumb and wrist. Frequently, pain will radiate up the dorsoradial aspect of the arm along the course of these muscles.
  1. On examination, there is swelling and tenderness over the first dorsal extensor compartment along the APL and EPB. Flexion-abduction of the thumb induces the pain, which is aggravated by passive ulnar deviation of the wrist (Finkelstein's test).
  2. Differential diagnosis includes arthritic conditions of the wrist or basal joint of the thumb and fracture, instability, or posttraumatic disorders of the carpal navicular bone. Injection of lidocaine into the tendon sheath can help establish the diagnosis.
  3. Treatment initially includes immobilization of the thumb and wrist with a splint and antiinflammatory medication [25 mg of indomethacin (Indocin) PO three times daily or 600 mg of ibuprofen (Motrin) PO three times daily] or injection with 4 to 8 mg of dexamethasone and lidocaine into the inflamed tendon sheath. In refractory cases, surgical release of the tight, thickened, inflamed tendon sheath has been uniformly successful.
Tendinitis and tenosynovitis with or without calcification. Any of the numerous tendons or sheaths about the hand and wrist may be involved with painful inflammation.
1. Physical examination. Localized swelling, tenderness, and crepitus will be present. Tenosynovitis commonly occurs in the extensor digitorum communis (EDC) along the dorsum of the hand or wrist; other extensors occasionally involved include the extensor carpi radialis, extensor pollicis longus, and extensor carpi ulnaris. On the palmar side, the flexor carpi ulnaris or radialis may be involved.
2. Laboratory studies. Radiographs may show calcifications along these tendons or in periarticular locations. Aspiration and crystal analysis may in some cases establish a specific diagnosis.
3. Treatment should include splinting of the inflamed lesion in a resting position and a course of nonsteroidal antiinflammatory medications such as indomethacin (25 mg PO three times daily). If symptoms are not relieved by these measures, dexamethasone injection and further splinting are indicated. Rarely is surgical treatment needed.
Infections in the hand are common and can cause significant disability. Most will respond favorably when general principles of care are followed. These include rest, elevation, immobilization (with early mobilization ), bacterial identification, appropriate antibiotic coverage, and surgical incision, drainage, and debridement when indicated. In cases that do not promptly respond favorably when these principles are followed, specific causes for the increased severity or chronicity should be sought. Predisposing systemic conditions include diabetes, hematologic malignancies, and circulatory disorders such as Raynaud's, Buerger's, or atherosclerotic disease. Predisposing local factors that may be responsible for poorly responding infections include retained foreign body, necrotic or sequestered tissue , or ineffective drainage.
1. Paronychia, the most common finger infection, is usually a staphylococcal infection of the soft tissues around the nail. It frequently results from rough manicuring or ill-advised picking of a hangnail.
  1. Physical examination. Severe pain, swelling, erythema, and sometimes pus are present, located at the base of and alongside the nail.
  2. Treatment
    1. Initial treatment should include warm soaks three times daily, elevation, and oral antibiotics with coverage for Staphylococcus [250 to 500 mg of cephradine (Velosef) or dicloxacillin PO q6h].
    2. If there is no resolution in 24 to 47 hours, or if a visible purulent collection is present, surgical drainage is advisable.
2. Felon is a painful infection of the distal pulp of the fingertip, with swelling, erythema, tenderness, and deep abscess formation.
  1. Initial treatment, including elevation, antibiotics, and protective splinting, may occasionally be successful.
  2. Usually, careful surgical incision and drainage of the deep pulp space loculations are needed. Antibiotic coverage and local care with dressing changes are usually followed by rapid healing once effective drainage has been performed.
3. Cellulitis, lymphangitis, and subcutaneous abscess. These infectious conditions are frequently seen in a busy emergency department.
  1. They may be caused by a scratch, abrasion, or puncture wound that secondarily becomes infected. Introduction of foreign or contaminated material through intravenous or subcutaneous needles by a drug abuser is another source of these types of infections.
  2. Treatment
    1. Initial treatment should include immobilization with plaster splints, strict elevation, and antibiotics.
    2. If fever , lymphangitis, and axillary adenopathy are present, hospital admission is advisable for intravenous antibiotics and controlled treatment.
    3. Surgical incision and drainage are indicated for well-localized abscess collections after 12 to 36 hours of intravenous antibiotic saturation.
4. Acute suppurative tenosynovitis is a relatively rare but dramatic serious infection involving the flexor tendons and sheaths that extend into the palm.
  1. There is usually a history of prior puncture. Pain is severe, extending along the palmar aspect of the finger into the palm. Motion of the finger exacerbates the pain.
  2. Physical examination. There is marked uniform swelling and erythema of the finger, which is held in partial flexion. Dorsal swelling also occurs because of the venous and lymphatic drainage pattern.
  3. Kanavel's four cardinal signs
    1. Pain with passive extension.
    2. Flexed position of the finger.
    3. Uniform swelling into the palm.
    4. Tenderness along the flexor sheath into the palm.
  4. Treatment
    1. Initial treatment should include aspiration of the tendon sheath under sterile conditions. Gram's stain and culture are obtained before intravenous antibiotics are begun. Purulent tenosynovitis is a potentially destructive infection of the tendon sheath that can destroy the flexor tendon and extend into the palm, deep structures of the hand, and other tendons.
    2. Early surgical decompression , irrigation, and judicious debridement are indicated for this serious infection.
5. Septic arthritis is most commonly seen in the MCP joints.
  1. These infections are most often caused by a human or animal bite, tooth abrasion, or clenched fist in mouth injury.
  2. The presentation is one of severe pain, swelling, and erythema about the wound on the dorsum of the hand. Motion is painful and limited. Seropurulent discharge can frequently be expressed .
  3. Treatment. Hospital admission for surgical incision and debridement in addition to immobilization, elevation, and administration of intravenous antibiotics is recommended.

VI. Injuries of the fingers

Subungual hematoma. This extremely painful condition usually results from trauma to the distal finger (e.g., car door slam, hammer blow).
1. Immediate elevation and immersion in ice water may reduce the nail pain and bleeding.
2. Relief of pain is dramatic if the nail bed is carefully punctured over the hematoma area with a paper clip prong that has been inserted in a flame until red hot. Soak the finger in antiseptic solution and then apply a bandage.
Flexor tendon rupture . Pain in the palmar aspect of the finger can be caused by rupture of the FDP tendon from its insertion into the distal phalanx.
1. A history of sudden pain in the finger while grabbing (e.g., a football jersey, a stumbling child) is classic.
2. Methodic testing of FDP function (see section III.B.6 ) establishes the diagnosis.
3. Treatment. Surgical repair is the treatment of choice.
Mallet finger. Similar trauma may rupture the terminal extensor tendon to produce a flexed distal phalanx and an inability to extend the DIP joint actively. The pain here is localized over the dorsum of the joint.
1. Radiographs of the affected finger are necessary, as avulsion fractures of the distal phalanx may occur as the tendon ruptures.
2. Treatment consists of application of an aluminum foam splint to the dorsal surface of the finger, immobilizing only the DIP joint in extension (avoid hyperextension). A dorsal splint spares the palmar tactile surface and allows PIP joint motion during the necessary 6 weeks of splinting.
Fractures and dislocations of the hand are classified by the nature and site of injury and whether the skin surrounding the injury is open or closed.
1. Careful examination of the hand for angular or rotational deformities and proper anteroposterior and true lateral radiographs are necessary.
2. Treatment. Intraarticular, displaced, or potentially unstable fractures usually require reduction and stabilization with Kirschner wires.

VII. Arthritic conditions involving the small joints of the hand and wrist are frequently seen in cases of rheumatoid arthritis (RA), osteoarthritis , or posttraumatic arthritis. Treatment depends on the sites and severity of involvement and is individualized based on the patient's functional disabilities and overall needs. General goals in the care of arthritic hands are to relieve pain, prevent or correct deformity, and maintain or improve function.

Rheumatoid arthritis is a systemic autoimmune disease that frequently involves the hand and wrist (see Chapter 28).
1. The wrist, MCP, and PIP joints are most frequently involved.
2. Erosive synovitis, pain, stiffness, progressive deformity, and loss of function are the hallmarks of this disease process.
3. Radiographically, one sees generalized osteoporosis, joint space narrowing, and periarticular erosions, particularly of the carpal bones and metacarpophalangeal joints.
4. Pain and stiffness are frequently worse in the morning. As the disease progresses, the fingers may become deformed, and the classic ulnar drift may develop. Swan neck and boutonniere deformities are common.
5. Carpal tunnel syndrome, trigger finger or thumb, dorsal wrist synovitis, flexor tenosynovitis, and tendon ruptures are frequently encountered.
6. Treatment should be comprehensive. A team approach utilizes the combined expertise of rheumatologists, surgeons, and therapists, as well as psychologists and social workers.
  1. Initial treatment should include aspirin or nonsteroidal antiinflammatory medications, occupational therapy for splinting, and judicious functional exercises as indicated. Systemic steroids, intraarticular injections, and surgery are indicated in aggressive or refractory cases.
  2. Surgery is primarily indicated for severe pain, chronic aggressive synovitis that is unresponsive to adequate medical treatment, nerve entrapment syndromes, tendon ruptures, and deformities resulting in impaired hand function.
Osteoarthritis is common in adults (see Chapter 44).
1. It most frequently involves the interphalangeal joints, especially the DIP joints of the fingers and the carpometacarpal (CMC) or basal joint of the thumb.
2. It is caused by repetitive abnormal physical stress with subsequent activation of tissue factors and consequent joint wear, destruction, and juxtaarticular changes.
3. Pain, swelling, stiffness, and joint malalignment are hallmarks of the disease.
4. Radiographically, one sees joint space narrowing, marginal osteophytes, sclerosis, and subchondral cysts.
5. Heberden's nodes (marginal osteophytes), with or without mucous cysts, occur at the DIP joints. These are often inflamed and painful. Initial treatment with topical steroid cream and protective covering may provide a beneficial response in 1 to 2 months. Surgical excision of cysts and underlying osteophytes arising from the arthritic joint can provide relief of symptoms and cosmetic improvement.
6. Bouchard's nodes (marginal osteophytes) at the PIP joints and radial dorsal osteophytes at the thumb basal joint are indicators of degenerative arthritis at these joints. Pain, swelling, tenderness, malalignment, and loss of pinch strength are the characteristic clinical findings.
7. Treatment
  1. Antiinflammatory medications, occupational therapy, and a supportive abduction thumb splint can provide significant relief of pain and improve function.
  2. Surgical debridement of osteophytes, excision of cysts, arthroplasty, or fusion may be indicated for advanced disease.

VIII. Tumor and swelling

Ganglions
1. Ganglions are the most common soft-tissue tumor in the hand. They most frequently present as painless, firm dorsal swellings around the wrist. They may also occur over the volar wrist and in the hand near the MCP flexion crease at the base of the fingers. Although their etiology is unknown, ganglions are cystic swellings containing mucinous material that are closely connected to joints or tendon sheaths. They transilluminate in a darkened room.
2. Ganglions rarely interfere with hand function, but on occasion, particularly after strenuous activity, they may become painful.
3. Radiography may reveal underlying pathology (i.e., dorsal spurs of the carpal bones).
4. Treatment. Ganglions may be aspirated, providing diagnostic confirmation, and injected with a steroid suspension; however, recurrence is common. Aspiration, if attempted, should be performed with an 18-gauge needle, as ganglionic fluid is extremely viscous. Surgery is indicated for painful ganglion, symptomatic recurrence, and cosmetic complaints.
Giant cell tumor of the tendon sheath (pigmented villonodular synovitis) is a locally aggressive, benign tumor arising from synovium and periarticular tissues. It is the second most common tumorous growth in the hand. It is usually painless but may cause mild pain or local nerve compression. Joint motion is occasionally impaired when impingement is caused by the size or location of the growth. Generally, these reactive lesions are slow-growing, but they may invade tendon or bone. They are solid tumors and therefore do not transilluminate. Surgical excision is warranted to confirm the diagnosis and to relieve pain and nerve compression and improve cosmesis. Recurrence after excision is common.
Synovitis of rheumatoid disease may present as swelling over the PIP, MCP, and wrist joints and over the dorsum of the hand. Swelling over the dorsum of the hand should not be confused with an infectious process. Motion of the fingers and wrist may be limited.
1. Aspiration may be attempted if the diagnosis is doubtful, but care should be taken not to convert a synovial swelling into an iatrogenic infection.
2. Treatment. Immobilization by splinting, together with an appropriate antiinflammatory medication, is indicated for therapy of the acute attack. Tenosynovectomy may be indicated in selected patients with refractory dysfunction.
Swelling of disuse. Normally active hand motion is essential to promote venous and lymphatic drainage. Any condition that causes an absence or decline of hand motion will promote the collection of edematous fluid and lead to diffuse hand swelling, stiffness, and ultimately loss of function. Bed rest and inactivity resulting from an unrelated condition (myocardial infarction, skeletal traction, sciatica) may lead to this potentially disabling condition. Physician awareness of the problem and the services of a trained therapist are essential to manage the problem.
The carpometacarpal boss is a bony prominence involving the CMC joints of the index and long fingers. It may appear in conjunction with a ganglion.
1. Pain and tenderness are caused by underlying arthritis of the CMC joints.
2. Treatment with antiinflammatory medications and a short period of immobilization may provide symptomatic relief. If surgical treatment is indicated (rarely, for refractory pain), the underlying CMC joint arthrosis should also be addressed when the dorsal bony prominence is excised.

IX. Hand deformities may be associated with previous traumatic injuries to joints, tendons, or nerves, with arthritic conditions, or with progressive fascial contracture.

Dupuytren's contracture is a process of painless thickening and contracture of proliferative longitudinal bands of the palmar aponeurosis, which lies between the skin and flexor tendons. The tendons are not primarily involved. Dupuytren's contracture occurs most commonly in male subjects (90%), is often bilateral, and frequently is associated with diabetes, heavy alcohol consumption, seizure disorders, repetitive trauma, and a family history of the disease.
1. History. Patients complain of thickened bands, inability to open their hands fully, and difficulty with handshakes or grasping large objects. The ring and little fingers are most often involved.
2. Physical examination reveals the fixed flexed position of the finger, palpable nodules, and thickened longitudinal cords in the palm extending into the fingers.
3. Treatment. Surgical excision is recommended if the contracture impairs function or if fixed metaphalangeal and PIP contractures are progressive.
Swan neck. This abnormality consists of hyperextension of the PIP joint and flexion of the DIP joint. It may occur following trauma or, more commonly, in RA.
1. Anatomically, synovitis causes erosion of the volar stabilizing elements, allowing PIP hyperextension and dorsal displacement of the extensor apparatus. With contracture of the joint and extensor apparatus, PIP flexion is impossible , and deformity can be severe.
2. Treatment. In the early posttraumatic condition, splinting may be attempted with the deformity reversed (PIP flexed and DIP extended) for a 6-week period. Surgical correction is necessary if hand function is sufficiently impaired.
Boutonniere. Disruption of the extensor mechanism over the PIP joint from trauma, laceration, or synovitis will produce flexion of the PIP joint and extension of the DIP joint. The deformity is not as functionally disabling as swan neck deformity because grasp function is still possible. Acute therapy consists of splinting the finger with the PIP joint extended and the DIP joint flexed. Surgical reconstruction may be necessary if disability is marked.
Extensor tendon ruptures without laceration are uncommon except in patients with chronic RA. Rupture probably results from multiple factors, notably compromise of the tendon blood supply as a result of florid tenosynovitis. Rupture of EDC4+5 is common at the site of dorsal dislocation of the distal radioulnar joint from rheumatoid synovitis. The presenting complaint of inability to extend the thumb or finger should alert the examiner .
1. Examination of the resting posture of the hand will demonstrate increased flexion of the digit or digits; active extension of the digits will not be possible. These extensor tendon ruptures are usually painless and may go unnoticed by the patient.
2. Treatment. Early surgical consultation is advised because single extensor tendon rupture puts more strain on the remaining tendons and often heralds a chain of tendon ruptures across the dorsum of the hand.
Claw hand is a deformity manifested by flattening of the hand arches, hyperextension of the MCP joints, and flexion of the interphalangeal joints. It may be caused by ulnar or combined nerve paralysis, brachial plexopathies, or central nervous disorders. It results from an imbalance of the intrinsic and extrinsic muscles. In the presence of intrinsic weakness, overpull of the long extensors causes MCP hyperextension and clawing of the fingers as a consequence of powerful interphalangeal flexion from the long flexors.

X. Abnormalities of sensation

Carpal tunnel syndrome is produced by compression of the median nerve at the wrist. As the nerve passes through the unyielding carpal tunnel, it is at risk for compression by the transverse carpal ligament. In most patients, no specific etiology can be determined, but thickening and proliferation of the peritendinous synovium is seen. This condition is very common in RA, in diabetes, during or after pregnancy , and after wrist fracture. It is also seen in postmenopausal women and in patients with the myxedema of thyroid disease.
1. A history of wrist pain and paresthesias in the thumb, index finger, and long finger (the median nerve distribution), frequently occurring at night, is fairly typical. The patient may report being awakened by the pain and paresthesias and needing to shake the hand for relief. The lack of muscle activity at night allows fluid accumulation, and wrist flexion during sleep is thought to account for this exacerbation of symptoms. Patients may also report daytime paresthesias, clumsiness or dropping of objects, and weakness of pinch or grasp.
2. Physical examination may demonstrate a mild flattening of the thenar eminence. Light touch with a cotton applicator along the radial border of the ring finger and both sides of the index finger and thumb will demonstrate a decrease in sensation. Care must be taken to apply the applicator along the palmar surface of the digit, as the dorsum of the fingers is supplied by the radial and ulnar nerves. A decrease in two-point discrimination occurs late in the neuropathy. Thumb opposition , the ability to draw the thumb away from the palm and oppose the thumb pulp to the pulp of the little finger, may be diminished. Tapping the volar surface of the wrist over the median nerve may produce Tinel's sign, which appears as shooting pain in the long or index finger and indicates median nerve compression. Phalen's sign, also helpful, is performed by flexing both wrists for 30 to 60 seconds to elicit median nerve numbness in the affected hand.
3. Electromyography and nerve conduction studies may confirm a delay in nerve conduction across the carpal canal and denervation of thenar musculature.
4. Treatment
  1. Splints to hold the wrist in slight extension during sleep.
  2. A 40 mg dose of methylprednisolone injected into the area of the carpal canal provides some relief in early cases. Care must be exercised to avoid injuring the median nerve and flexor during injection.
  3. Surgical release of the transverse carpal ligament is indicated if the response to local measures is poor or if the neurologic deficit progresses.
Ulnar nerve entrapment may occur at the wrist as the ulnar nerve passes through the tight canal (of Guyon). It may be seen after wrist trauma, in patients with RA, and in jackhammer workers.
1. History. Symptoms include weakness of the intrinsic muscles of the hand and numbness in the ulnar nerve distribution.
2. Laboratory studies. Diagnosis is confirmed with nerve conduction studies and electromyography.
3. Treatment is usually local injections of methylprednisolone and surgical decompression if symptoms persist or neurologic dysfunction progresses.

¹ Bell, Sir Charles. The hand, its mechanism and vital endowments, as evincing design. Philadelphia: Coney, Lea and Blanchard, 1833.

Bibliography

Burton RI, Littler JW. Nontraumatic soft tissue afflictions of the hand. Curr Probl Surg 1975;July:1.

Burton RI, et al. The hand, examination and diagnosis, 2nd ed. American Society for Surgery of the Hand. New York: Churchill Livingstone, 1983.

Kleinart HE. Trauma of the hand. Curr Probl Surg 1978;10:1.

Lampe EW, Netter FHL. Surgical anatomy of the hand, with special reference to infections and trauma. Found Clin Symp 1969;3.

Lister G. The hand, diagnosis and indications . New York: Churchill Livingstone, 1983.

Books@Ovid
Copyright 2000 by Lippincott Williams & Wilkins
Stephen A. Paget, M.D., Allan Gibofsky, M.D., J.D. and John F. Beary, III, M.D.
Manual of Rheumatology and Outpatient Orthopedic Disorders

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