The Forearm, Wrist, And Hand

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Chapter 7 The Forearm, Wrist, and Hand

The importance of the wrist and hand is evidenced by the fact that the rest of the upper extremity functions primarily to place the hand in a position where it can operate most effectively. Treatment of the wide variety of disorders that occur in the hand requires an understanding of its complicated anatomy and functional physiology.

Anatomy

SKIN, FASCIA, AND NAIL

The skin on the dorsum of the hand is loose and overlies a subcutaneous space through which pass many veins and most of the lymph vessels of the hand. This abundance of lymph vessels accounts for the dorsal lymphedema that commonly occurs secondary to infection in the palm or fingers. The palmar skin, however, is firmly attached to the underlying palmar aponeurosis, which is continuous with the palmaris longus tendon (Fig. 7-1). This thick fascia sends extensions into the fingers and protects the important deeper structures of the hand. It may become nodular and shortened in Dupuytren’s contracture.

Fig. 7-1 The palmar aponeurosis.

The nail of each finger originates close to the distal interphalangeal joint and is surrounded on the sides and at the base by thick folds of tissue, the paronychium, and the eponychium, respectively. It covers a rich capillary bed that may be tested to determine the circulation of the extremity. The nail should be retained, whenever possible, in fingertip injuries.

BLOOD SUPPLY

Most of the blood supply to the hand enters on the palmar aspect through the radial and ulnar arteries. Each of these arteries terminates in a superficial and a deep branch. The superficial branches join to form the superficial palmar arch, which is located at the level of the base of the first web space. The deep palmar arch, located 1 cm proximal to the superficial arch, is formed by the junction of the deep branches. The arches are named for their position relative to the flexor tendons. Many branches and anastomoses from these arches provide the blood supply to the fingers and hand. In the fingers, digital vessels (and nerves) lie just ventral to the flexor skin crease of the interphalangeal joints (Fig. 7-2).

Fig. 7-2 The neurovascular bundle is situated just ventral to the flexor skin crease.

MUSCLES OF THE HAND

Motions of the wrist and fingers are controlled by groups of muscles that are classified as either intrinsic or extrinsic. Intrinsic muscles arise within the hand and are responsible for the delicate movements of the fingers. Thenar refers to intrinsic muscles of the thumb. Hypothenar refers to those on the ulnar side of the hand. Extrinsic muscles are those that take origin within the forearm.

EXTRINSIC MUSCLES

Motion at the wrist is accomplished by the various wrist flexors and extensors. In addition to providing wrist motion, these muscles stabilize the wrist in slight dorsiflexion, a position that allows maximum function of the extrinsic finger flexors.

Nine finger flexors and the median nerve pass into the hand through the carpal tunnel beneath the transverse carpal ligament (Fig. 7-3). Five deep flexors pass to the distal phalanx of each finger and thumb, and four superficial flexors pass to the middle phalanx of each finger. Each of these finger flexors can be tested individually (Fig. 7-4).

Fig. 7-3 Structures proximal to the wrist joint. The ulnar nerve (U) and artery continue distally through the ulnar tunnel of Guyon. The nine finger flexors (F, FPL) and median nerve (M) pass through the carpal tunnel beneath the transverse carpal ligament. Note the superficial location of the median nerve and the sublimis to the long and ring fingers. FCR, Flexor carpi radialis; PL, palmaris longus.

Fig. 7-4 A, The sublimis is functioning if the proximal interphalangeal joint can be flexed while the adjacent fingers are held extended. B, The profundus is functioning if the distal interphalangeal joint can be flexed while the rest of the finger is stabilized.

The finger flexors pass beneath a series of ligaments between the distal palmar crease and the distal interphalangeal joint. These annular ligaments, or “pulleys,” prevent the tendon from bowstringing. Tendon repair in this area called “no-man’s land” is often unrewarding because of adhesions that form between the lacerated tendon ends and these ligaments.

The extensor tendons pass dorsally over each finger and thumb and insert into the phalanges. They extend the proximal phalanges and assist the intrinsic muscles in interphalangeal joint extension. The thumb extensors are easily palpated at the anatomic “snuffbox.”

INTRINSIC MUSCLES

The thenar (median nerve) and hypothenar (ulnar) muscles act primarily to position the thumb and small finger for the purpose of pinching. The rest of the intrinsic muscles (interossei and lumbricals) insert into the proximal phalanges and extensor hoods and assist in flexion of the metacarpophalangeal joints and extension of the interphalangeal joints.

NERVE SUPPLY

The ulnar nerve provides the motor supply to all of the intrinsic muscles of the hand, except the two radial lumbricals and the thenar muscles. It also provides sensation to the entire ulnar 1½ fingers (Fig. 7-5). Its function is easily evaluated by testing finger abduction and palpating the belly of the first dorsal interosseous muscle (Fig. 7-6).

Fig. 7-5 Dorsal (A) and palmar (B) sensation of the hand. R, Radial nerve; U, ulnar nerve; M, median nerve.

Fig. 7-6 A, Testing for ulnar motor function. B, Testing for median nerve function by determining thenar muscle strength. C, Testing for radial nerve function by examining wrist extension against resistance.

The thenar muscles and the two radial lumbricals are supplied by the median nerve, which also supplies sensation to the palmar aspect of the radial 3½ fingers as well as the tips of these fingers on their dorsal aspect. Its function is evaluated by testing opposition of the thumb to each finger and observing the thenar muscles for contractions.

The radial nerve has no intrinsic muscle supply but does provide sensation to the dorsum of the hand over the radial 3½ fingers. It supplies motor function to the extrinsic wrist and finger extensors.

BONES AND LIGAMENTS

The carpal bones contribute to the mobility of the hand by allowing flexion, extension, and radial and ulnar deviation to occur. The eight carpal bones are arranged into a distal and proximal row. Strong ligaments bind them together, one of the strongest being the transverse carpal ligament. At the metacarpophalangeal and interphalangeal joints, strong collateral ligaments provide mediolateral stability.

Roentgenographic Anatomy

The 27 bones of the hand are visualized by anteroposterior, lateral, and oblique roentgenograms when appropriate (Fig. 7-7).

Fig. 7-7 Roentgenographic anatomy of the wrist. H, Hamate with its prominent hook; C, capitate; L, lesser multangular (trapezoid); G, greater multangular (trapezium); T, triquetrum; P, pisiform; L, lunate; N, navicular (scaphoid); U, ulnar styloid; R, radial styloid. On the lateral view, note that the capitate, lunate, and distal portion of the radius are in a direct line.

Carpal Tunnel Syndrome

Carpal tunnel syndrome, or compression of the median nerve at the wrist, is the most common entrapment neuropathy in the upper extremity. Compression of the nerve beneath the transverse carpal ligament probably develops as a result of an increase in the volume of the contents in the carpal tunnel. The cause is unknown in most cases. Tenosynovitis of the flexor tendons may be present in some cases, but whether the disorder should be considered an “overuse” condition is controversial. The disorder may be seen in association with hypothyroidism, rheumatoid and gouty arthritis, and aberrant or anomalous muscles in the wrist. A deficiency in vitamin B₆ has even been postulated as a cause. Carpal tunnel syndrome is sometimes seen following fractures of the wrist and is not uncommon in the third trimester of pregnancy. (NOTE: When it does occur late in pregnancy, the symptoms of carpal tunney tend to subside after delivery, often quite dramatically within a few days. Thus, treatment is strictly symptomatic, and surgery is generally not recommended in these cases. The disorder often recurs in subsequent pregnancies.) The syndrome is bilateral in up to 50% of cases. Whether occupational and job-related activities are risk factors remains undetermined.

Sometimes, a combination of neck and hand pain can develop, especially in patients who suffer from degenerative cervical disc disease. This is termed the “double-crush syndrome” lesion and results from nerve compression at two separate levels, the neck and the wrist. This suggests that proximal compression may decrease the ability of the nerve to tolerate a second, more distal compression.

Ulnar Tunnel Syndrome

Pain or numbness along the ulnar border of the hand secondary to compression of the ulnar nerve in its “tunnel” (Guyon’s canal) at the wrist is much less common than median nerve compression. It may result from pressure on the nerve by soft tissue tumors, ganglia, constricting bands or muscles, or thrombosis of the ulnar artery. The incidence is high in bike riders. The symptoms and signs are similar to those found with carpal tunnel syndrome, except that they are ulnar nerve in distribution. They are also similar to cubital tunnel syndrome, except that the forearm is not affected and sensation to the dorsum of the hand and dorsal ulnar 1½ fingers is intact, because the dorsal sensory branch of the ulnar nerve passes to the back of the hand proximal to the ulnar tunnel at the wrist.

The treatment is the same as that for carpal tunnel syndrome, except cortisone injections are not given. Surgical release of the Guyon’s tunnel is sometimes necessary.

Ganglion

Ganglions are soft tissue lesions that are commonly found in the extremities. They are always found adjacent to a joint or tendon sheath. The cause is unknown, but myxoid degeneration of connective tissue and repetitive trauma with chronic irritation are possible causes. The cyst contains a very thick mucinous material and usually has a stalk that can be traced to a tendon sheath or joint.

The ganglion cyst is the most common soft tissue mass in the hand. The usual location is the dorsum of the wrist at the scapholunate ligament, but volar cysts radial to the palmaris longus are not rare. A similar cyst can develop from the flexor tendon sheath near the base of the finger at the metacarpophalangeal (mcp) joint flexion crease. Ganglions are occasionally seen in children but frequently subside spontaneously in this age group in 2 to 3 years.

CLINICAL FEATURES

A history of trauma is rarely elicited. Local pain and a feeling of weakness may be noted, but many are asymptomatic. The mass may change in size, with this change often being related to the level of activity of the patient. Ganglia are most common on the dorsum of the wrist. They are more prominent with the wrist flexed and are usually freely movable (Fig. 7-10).

Fig. 7-10 A, Dorsal ganglion cyst. B, The volar wrist ganglion and flexor tendon sheath cyst in their usual locations.

An “occult” ganglion may be the source of local dorsal wrist pain. Clinically, it is difficult to detect because it is deep to the extensor tendons. Special imaging studies such as magnetic resonance imaging (MRI) may be needed to determine its presence.

TREATMENT

Simple observation is recommended if symptoms are minimal. Ganglia resolve spontaneously in approximately 40% to 50% of cases. A cure may be effected by aspirating or puncturing the cyst in multiple areas and injecting it with a steroid compound (Fig. 7-11). A large (18-gauge) needle is required to aspirate the thick gel. A compression pad is then applied over the lesion for 48 to 72 hours. Recurrence is common.

Fig. 7-11 Aspiration of ganglion. Because a large-gauge needle is needed to aspirate the thick fluid, the skin site should be first infiltrated with local anesthetic. Digital pressure of the cyst may help express the fluid toward the needle tip; 1 mL of steroid is injected when aspiration is complete.

If symptoms persist, excision of the cyst may be indicated. The recurrence rate is 5% to 10%.

Degenerative Arthritis

Although osteoarthritis of the wrist and hand is much less common than in the lower extremities, it is sometimes more disabling. In the hand, it is 10 times more common in the females than males, and the most common area of involvement is the trapeziometacarpal or “base joint” of the thumb (Fig. 7-12). Involvement at the base joint of the thumb is particularly bothersome because of the tremendous mobility required by this joint in daily use. Sometimes deformity of this joint even develops the appearance of a “mass” because of osteophyte formation, swelling, and subluxation. The arthritis is considered “primary” in most cases but can also develop secondary to fractures and other joint injuries. When the distal interphalangeal (DIP) joints become involved with arthritis, persistent nodular swellings called Heberden’s nodes may develop. Similar lesions at the proximal interphalangeal (PIP) joints are termed Bouchard’s nodes. Occasionally, mucous cysts also develop at these interphalangeal (IP) joints.

Fig. 7-12 A, Osteoarthritis (arrow) of the carpometacarpal joint of the thumb. Joint space narrowing and marked subluxation of the base of the metacarpal are present. B, Generalized osteoarthritis of the wrist.

TREATMENT

Treatment is similar to arthritis elsewhere. Anti-inflammatory medication, intermittent splinting, moist heat, and occasional local cortisone injections are usually successful in temporarily relieving symptoms (Fig. 7-13). Cystic lesions may be aspirated but should not be drained open. Patients with refractory symptoms should be referred. Arthroplasty and arthrodesis are occasionally necessary to control pain.

Fig. 7-13 Injection of the carpometacarpal joint of the thumb for osteoarthritis. Distal traction on the thumb may open the joint for easier access; 1 mL of medication is usually sufficient. The base of the metacarpal is usually prominent and serves as a landmark.

Dupuytren’s Contracture

Dupuytren’s contracture is a disease of the palmar fascia in which progressive contractures of the fascia occur and sometimes lead to a flexion deformity of the distal portion of the palm and fingers. The cause is unknown, but it is often hereditary and bilateral. Predisposing disorders are diabetes, alcoholism, epilepsy, and liver disease. It is seen more often in Scandinavians, and some northern Europeans have a 25% prevalence in patients over the age of 60. Lesions develop more often and earlier in certain families. It is 10 times more common in males, and 5% of patients develop a similar condition elsewhere, such as Peyronie’s disease or Ledderhose disease (involvement of the plantar fascia). Soft tissue “pads “in the knuckles may also be present. Individuals with these additional findings are considered to have Dupuytren’s diathesis, and their disease is generally more severe and recurrent.

Pathologically, the contracture consists of proliferating vascular fibrous tissue that later develops into mature collagen.

CLINICAL FEATURES

The disorder is usually painless. Age of onset is usually between 40 and 60 years. Deformity and interference with the use of the hand by the flexed, contracted fingers are the most common complaints. The process usually begins on the ulnar side of the hand, often starting at the ring finger. An isolated nodule may appear in this area that eventually hardens and later disappears. The overlying skin becomes adherent to the fascia, and a strong fibrous cord develops that extends into the finger (Fig. 7-14). In the later stages of the disorder, the cord may begin to contract and pull the finger into flexion. Multiple fingers may be affected.

Fig. 7-14 Dupuytren’s contracture. A flexion deformity of the finger is present, with nodular thickening of the fascia to the ring finger.

TREATMENT

The treatment is often surgical, although stretching exercises may help prevent contractures in the early stages. Fasciectomy is indicated as soon as joint contracture occurs. If performed early, complete restoration of extension can be anticipated. Nodules without contracture usually require no treatment. Referral is indicated if contracture begins to develop.

Stenosing Tenosynovitis

This common condition of unknown origin may develop from overuse or direct trauma. The resultant inflammation and irritation hinder the normal gliding motion of the tendon. Most cases are primary (idiopathic), although the condition can develop in patients with rheumatoid arthritis. Several distinct syndromes can be described, depending on the site of involvement.

DE QUERVAIN’S DISEASE

Tenosynovitis frequently occurs in the first dorsal extensor compartment of the wrist (Fig. 7-15). The extensor pollicis brevis and abductor pollicis longus occupy this compartment and are involved where they cross over the radial styloid.

Fig. 7-15 A, The first dorsal extensor compartment. B, Finkelstein’s test. Pain is reproduced in the first dorsal compartment by passively flexing the thumb and adducting the wrist.

CLINICAL FEATURES

Pain and tenderness are usually present at the first dorsal compartment, and crepitus with motion of the tendon may be noted. The pain may radiate up the forearm and down into the thumb. Active and passive motion of the thumb aggravates the pain, and local thickening of the tendon sheath is frequently present. Characteristically, pain is reproduced by passive stretching of the affected thumb tendons (Finkelstein’s test). The overlying radial sensory nerve may become involved because of adjacent inflammation, leading to tingling or numbness over the thumb and web space. Long-standing inflammation may even cause a tendon sheath cyst to develop near the radial styloid. Because of the close proximity of the basal joint of the thumb, de Quervain’s disease is often confused with osteoarthritis in this joint. Radiographic studies are usually helpful in differentiating the two disorders.

TREATMENT

Treatment in mild cases includes nonsteroidal anti-inflammatory drugs (NSAIDs), immobilization, avoidance of the offending activity, and steroid injections into the tendon sheath (Fig 7-16). Braces or other immobilizing devices should always include the thumb as well as the wrist. Moist heat is applied as necessary for comfort.

Fig. 7-16 Injecting for de Quervain’s tenosynovitis. The synovial compartment is gently grasped between the thumb and index fingers. These fingers can be used as a “sight” with the needle being inserted midway between them. Flow of the fluid up and down the sheath confirms the needle is in the sheath and not the tendon. Resistance to injection indicates incorrect placement, and the needle tip should be repositioned.

The symptoms usually subside with conservative treatment, but if they persist, surgical release of the tendon sheath is indicated.

TRIGGER FINGER AND THUMB

If swelling of the flexor tendon and sheath occurs, passage of the tendon through the constricted sheath may become difficult (Fig. 7-17). This may result in snapping or “triggering” of the affected finger at the MP joint as the swollen, nodular tendon passes through the constricted sheath. The symptoms are frequently worse after rest and improve with active use of the finger. The effect of the triggering itself is transmitted distally to the DIP joint. The finger may even lock completely in either flexion or extension. If the digit locks in flexion, manipulation may be required to extend the finger, a maneuver usually accompanied by a palpable snap. In mild cases, however, the triggering effect may be subtle. Examination usually reveals tenderness and a firm swelling at the proximal flexor pulley. If multiple fingers are involved, rheumatoid disease should be suspected. A congenital form is occasionally seen in the thumb of children.

Fig. 7-17 Trigger finger. In (A), the nodule is proximal to the first pulley. With extension (B), the nodular tendon thickening (along with narrowing of the sheath) prohibits smooth passage of the tendon causing the typical “triggering” effect. The finger may even completely lock in flexion or extension. The nodular thickening is usually palpable and often quite tender.

The treatment is the same as that for de Quervain’s disease. Sometimes splinting only the DIP joint is needed. Surgical release is frequently necessary, but many patients, especially children, recover spontaneously.

EXTENSOR CARPI RADIALIS TENOSYNOVITIS

Pain and tenderness affecting the radial wrist extensors are occasionally seen in heavy laborers. The symptoms, signs, and treatment are similar to those in de Quervain’s disease.

Intersection syndrome is a term sometimes used to describe a tenosynovitis in which the extensor pollicis brevis and abductor pollicis longus cross over the wrist extensors. Symptoms and signs of inflammation are present with swelling and point tenderness, The area of involvement is 6 to 8 cm proximal to the radial styloid. Crepitus with active extension of the wrist is common.

Repetitive Motion Syndrome

This syndrome is a controversial diagnosis, in which pain develops in the forearm and hand during the course of normal activities, usually in the workplace. Among the other names used are cumulative trauma disorder and repetitive strain injury. Because of the inability to establish any clear source for the problem, the term idiopathic arm pain is commonly used. A similar chronic pain syndrome may be seen in the neck and shoulder area as well as the lower part of the back. The disorder has been the subject of much media attention and has even set labor against management in many large industries. It has also been the source of a great deal of litigation, mainly directed at workers’ compensation carriers. The condition appears to reflect a complicated mixture of physical and psychosocial factors.

Some reasons for the controversial nature of the disorder are as follows:

1 It is not known whether the condition is really an “injury” and is therefore compensable under law.

2 It is not known whether the syndrome is simply discomfort or whether any actual harm or damage ever results.

3 Frequently, there is an absence or paucity of objective physical findings to support any clear working diagnosis or explanation for the pain.

4 There is considerable controversy surrounding a number of epidemiologic studies based on data gathered from the workplace.

CLINICAL FEATURES

Typically, pain occurs in the forearms following activity. The pain may not even be improved by rest or restricted activities. The syndrome sometimes presents with symptoms consistent with one or more disorders known to cause upper extremity pain. Thus, some patients may present with symptoms compatible with tenosynovitis, whereas others may suggest occupational cramps, epicondylitis, reflex sympathetic dystrophy, thoracic outlet syndrome, carpal tunnel syndrome, or even a combination of several disorders. Frequently, the symptoms are vague. The patient often lacks specific objective physical findings, with only diffuse soft tissue tenderness being present.

Occasionally, however, there may be mild generalized hand swelling and tenderness of the median nerve. Results of electrical studies may even be abnormal in some patients without any symptoms suggestive of nerve compression. This causes difficulty in arriving at a specific diagnosis (and is misleading if surgery is being contemplated).

TREATMENT

The usual remedies are tried first: stretching exercises, moist heat, splints, rest, and anti-inflammatory medication. The splint should keep the wrist straight, not flexed or cocked, and the patient should avoid extremes of wrist position. Local steroid injections are occasionally useful if the condition is clearly defined. If possible, task modification, frequent breaks, and shortening the exposure time improve the situation, although this is not always possible in most job situations. Reassurance is important. Occasionally, surgery such as carpal tunnel release is indicated if the diagnosis is clearly established, but surgery often fails to resolve the patient’s symptoms and may even become a negative factor for returning the patient to work.

PROGNOSIS

Occasionally, some permanent “injury” may occur as a result of repetitive motion, but it is not common. There is little doubt that discomfort does occur, however, and many patients continue with symptoms despite job changes, with pain occurring even with slight domestic tasks. These patients can usually be allowed to work but frequently will experience discomfort with any light job. Unfortunately, very few jobs are available that do not require upper extremity use to at least some degree. Some patients may even have to completely change occupations.

Ulnar Nerve Entrapment (Cubital Tunnel Syndrome)

Cubital tunnel syndrome is the second most common nerve compression in the upper extremity. It may occur from several causes, but the most common is chronic trauma to the nerve where it passes behind the elbow. The nerve is most superficial at this location and is easily subjected to external pressure. Leaning on the elbow or repeated flexion and extension may also be factors in its onset. Elbow synovitis with synovial enlargement and muscular hypertrophy may also cause localized pressure in the tunnel. A cubitus valgus deformity at the elbow secondary to a growth plate fracture or infection may also cause paralysis (“tardy ulnar palsy”) by progressive stretching of the nerve in its groove behind the elbow (Fig. 7-18). The nerve may even sublux in and out of its groove on occasion, thereby giving rise to symptoms.

Fig. 7-18 Valgus deformity of the elbow that may gradually stretch the ulnar nerve and lead to paralysis (“tardy ulnar palsy”). This is often caused by growth plate damage of the lateral condyle.

Clinical Features

Minimal pressure against the elbow may lead to paresthesias and numbness along the distribution of the ulnar nerve in the forearm and hand, mainly the small finger (Table 7-1). Tinel’s sign is often positive. The elbow flexion test may be abnormal. This test is performed by having the patient flex the elbow for 30 to 60 seconds with the wrist extended. This maneuver increases the volume and pressure in the cubital tunnel and may reproduce symptoms. The test is not diagnostic, however, because it may be positive in asymptomatic individuals.

Table 7-1 Differential Diagnosis of Common Causes of Forearm and Hand Pain *

Disorder	Findings Present	Findings Absent
Carpal tunnel syndrome	Painful paresthesias along portions of median nerve (i.e., palm side of hand). Index and long often only fingers involved. May have night pain in long-standing cases. Pain may radiate as high as shoulder. Tinel’s sign may be positive at wrist.	Pain not worsened by resisted motion or stretching. No symptoms on dorsum of hand. Full range of motion.
Tenosynovitis	Pain and tenderness usually well localized to site of involvement. Pain may be reproduced by passive stretch or resistance against movement of affected tendon. May be local swelling.	No paresthesias. Full range of motion. No night pain.
Tennis elbow (most common lateral)	Pain may radiate from elbow to forearm and hand. Localized tenderness at epicondyle. Pain aggravated by resisted dorsiflexion of wrist (if lateral). Pain with gripping activities.	Full range of motion, no paresthesias or night pain.
Osteoarthritis	Local tenderness, sometimes with swelling of affected joint. Pain with motion. Decreased motion.	No paresthesias. Tinel’s sign negative.
Cubital tunnel syndrome	Painful paresthesias along ulnar nerve distribution in forearm and hand. Tinel’s sign may be positive behind medial epicondyle.	Full range of motion. Pain not worsened by resisted motion. No night pain.*

* Notes: Treatment and workup: 1. NSAID, moist heat, splint, and modification of activities as indicated for 2 to 4 weeks. 2. Roentgenogram, inject (if appropriate), change NSAID for 2 to 4 weeks. 3. Nerve conduction studies, referral as indicated.

In contrast to ulnar tunnel syndrome at the wrist, symptoms are also present on the dorsum of the hand and ulnar forearm. More severe involvement leads to progressive forearm, hypothenar, and intrinsic motor weakness (weak fanning of the fingers) and atrophy, especially the first dorsal interosseous muscle (Fig 7-19). If the nerve subluxes, the subluxation is usually palpable with elbow flexion and extension. Nerve conduction studies usually reveal delayed conduction at the elbow.

Fig. 7-19 Testing for intrinsic (ulnar) motor weakness. Always look for atrophy of the first dorsal interrosseus (curved arrow) when ulnar nerve lesions are suspected.

TREATMENT

Protecting the nerve from pressure may improve the symptoms in most mild to moderate cases. Elbow pads may be helpful. The patient should avoid keeping the elbow flexed for long periods of time, such as when talking on the phone. Keeping the elbow straight may be beneficial at night as well. A rolled towel wrapped around the elbow may be sufficient for this purpose. Otherwise, the treatment is usually surgical. The ulnar nerve is usually transferred anterior to the medial epicondyle, and any constricting bands are released. The pain is usually relieved immediately, but sensory recovery is often delayed, and motor function may not be completely restored. It is important, therefore, that all compression neuropathies undergo definitive treatment before significant motor weakness develops.

Kienbock’s Disease

Avascular necrosis of the carpal lunate bone is an uncommon disorder that may follow an injury. The cause is unknown, but the condition is considered to represent a circulatory disturbance to the bone. An abnormally short ulna (negative ulnar variance) may be a risk factor. A similar involvement of the navicular is termed Preiser’s disease.

CLINICAL FEATURES

The disorder is most common in men between the ages of 20 and 40. Although it is uncertain if trauma plays a role, a history is sometimes obtained of a single major injury. Multiple minor injuries, such as those that occur with certain manual occupations, may also lead to symptoms. Chronic pain, tenderness, swelling, and restriction of wrist motion (especially dorsiflexion) are common. The pain may be aggravated by passive dorsiflexion of the long finger in Kienbock’s disease or the index finger in Preiser’s disease. The initial roentgenogram findings are usually normal, but eventually the affected bone becomes abnormally dense and white (Fig. 7-20). Later, fragmentation and collapse occur. The end result is frequently degenerative arthritis throughout the wrist.

Fig. 7-20 Kienböck’s disease. The lunate is dense and sclerotic (arrow).

TREATMENT

In the early stages before collapse has occurred, intermittent immobilization for several months may permit reconstitution of the normal bony architecture. Surgery is often effective if performed before collapse has occurred.

Soft Tissue Injuries

FINGERTIP INJURIES

A variety of fingertip injuries are encountered in daily practice. By definition, these are injuries that occur distal to the DIP joint. Bone, skin, and nail may all be involved in varying degrees. Examination and treatment of most of these injuries may be performed under a metacarpal block using 1% lidocaine anesthesia. The anesthesia is instilled into the web space rather than the digit to prevent pressure on the digital vessels (Fig. 7-21). Epinephrine should not be used. A small Penrose drain applied to the base of the finger makes a satisfactory tourniquet. Some general principles in the treatment of these injuries should be followed:

1 Proper healing occurs only in a clean wound. Gentle cleansing and thorough debridement are mandatory.

2 The nail should be retained. It protects the nail bed, acts as a splint for bone and soft tissue, and prevents excessive dorsal scar formation. The partially avulsed nail should be restored to its normal position and held in place with one or two sutures through the nail into the adjacent soft tissue.

3 Repair the nail bed whenever possible. Sometimes, this requires elevation or even removal of the nail. Debride but try not to discard nail bed tissue if possible. Use 6–0 or 7–0 absorbable suture. Following repair, the nail is replaced and attached. Failure to repair the bed can result in scarring and future nail deformity. After repair, apply a nonadherent dressing that allows drainage.

4 Working surfaces should be replaced with as near-normal skin as possible.

5 Preserve length, especially the radial three digits (thumb, index, and long fingers).

Fig. 7-21 Metacarpal block. The anesthesia should be instilled into the web space. (The tourniquet is added later when the block becomes effective.)

The treatment of all fingertip injuries is directed toward coverage of the deeper tissue. This may be accomplished by simple closure, free grafts, or flaps. Major wounds should not be allowed to heal by the “open” treatment method without closure or coverage. Epithelialization of the wound will eventually occur but may take up to 12 weeks, and the resultant skin coverage is often thin and tender and breaks down easily.

SIMPLE CLOSURE

Simple closure is effective when skin loss is minimal and sufficient looseness of the surrounding skin and soft tissue is present to permit suturing of the wound without undue tension. A small portion of the distal phalanx may be removed with a rongeur. The scar line should be kept on the dorsal aspect if possible to prevent a tender scar on the volar aspect of the finger. Never trim “dog ears.” They will usually disappear with time, and trimming them may compromise healing.

Many minor soft tissue amputations of the pulp without bone loss that are less than 1 cm square can be treated by thorough cleansing, debridement, and healing by secondary intention, especially if the amputation is transverse or dorsal oblique (Fig. 7-22). (Even some amputations with minimal exposed bone may be treated in the same fashion if the protruding bone is shortened first.) Dressings are changed in 2 days and then daily, using tube gauze and petroleum jelly. Recovery is usually rapid (2 to 3 weeks). Significant volar pulp loss may be a contraindication to this method of care, where a padded flap graft might be more appropriate. If there is any question, it is always acceptable to temporize on fingertip injuries. The wound may be cleaned and dressed and referred for further care at a later date.

Fig. 7-22 A common type of fingertip amputation easily treated by epithelialization.

Even wounds larger than 1 cm in diameter may heal by secondary intention, and the maximal size of wound for which this technique is acceptable has not been determined. In children, this technique may be able to heal wounds up to 2 cm².

FREE GRAFTS

Free grafts are usually split thickness or full thickness. The thinner grafts tend to “take” better than do thicker grafts but do not afford the protection of a full-thickness graft. Although they may heal over bone or tendon, secondary revisions are often necessary. Their use should be limited to dorsal wounds or those without exposure of bone or tendon. These thin grafts may be obtained from a number of areas. The donor area often ends up being unsightly after healing, however, and should be chosen carefully. The thigh or lateral aspect of the buttock is a satisfactory donor site. Full-thickness grafts provide better protection for the volar aspect of the finger but have the same limitations as split-thickness skin grafts when used over bone and tendon. They are less sensitive and may be used on volar injuries. The flexor creases of the wrist and elbow are excellent donor sites. The donor wound is easily closed without undue tension in these areas. The graft should include no subcutaneous tissue. As with all grafting procedures, it is wise to plan backward and be certain that the graft will completely cover the area of the wound. If the patient brings in the amputated fingertip, it may be used as a full-thickness graft if it is in good condition. All fat must be removed before application. In children younger than 5 years of age, defatting the tip is not necessary. As healing progresses, full-thickness grafts may become dark after a few days. This should not be a cause for alarm, because the deeper portion is usually viable, despite the appearance of the more superficial layers.

FLAP GRAFTS

Extensive wounds may require local flaps. A variety of flap grafts are available depending on the need. These grafts provide more bulk and protection and are used when subcutaneous tissue is needed, for example, over bone and tendon. They are occasionally used by the experienced surgeon.

CRUSH INJURIES

Crush injuries are the result of direct violence to the tip of the finger. A painful subungual hematoma or fracture of the distal phalanx may occur (Fig. 7-23). The treatment of these injuries is directed at the soft tissues. After proper surgical site preparation and cleansing, an isolated painful hematoma may be drained before it has coagulated by gently drilling a hole into the nail with a No. 11 blade or an 18-gauge needle spun between the fingertips. A heated paper clip may also be used. When the hematoma involves 50% of the plate, nail bed laceration should be suspected. In these cases, the nail may need to be removed to repair the bed. The nail should be cleaned and replaced after the bed has been sutured. The nail may be perforated to allow drainage, but do not place the hole over the site of the repair.

Fig. 7-23 Fracture of the distal phalanx.

If the bed requires repair, small dorsally displaced fracture fragments that are exposed can be reduced and sutured with absorbable material. Minimally displaced fracture fragments are stabilized by the adjacent soft tissue and can usually be ignored. A tube-gauze compression dressing and ice are applied, and the hand is elevated to combat swelling. Warm soaks are started within 48 to 72 hours, and gentle motion is encouraged. An aluminum or plastic four-prong splint may help protect the end of the finger. Recovery is usually rapid, but complete reforming of the new nail may take up to 4 to 6 months.

EXTENSOR TENDON INJURIES

The extensor mechanism of each finger is a complex system, only a part of which is the extrinsic tendon itself. Restoration of normal function requires accurate diagnosis and repair. All skin lacerations over the hand should be thoroughly inspected for tendon injury, but special attention should be paid to lacerations over the MCP joint. Extensor tendon lacerations in this area are particularly difficult to diagnose because the injury frequently occurs with the MCP joint in flexion, and the examination is usually carried out with the finger in extension. The tendon laceration will then lie at a different level than the skin laceration and often goes undetected. With any extensor tendon injury, there is variable loss of active extension of the finger.

Lacerations in the extensor complex must be repaired accurately, and there should be no hesitation to extend the wound proximally or distally to properly visualize the ends of the tendon. Direct end-to-end repair using nonabsorbable suture such as nylon is desirable (Fig. 7-24). The finger and wrist are splinted in extension to remove tension from the suture line. Immobilization is maintained for approximately 4 weeks.

Fig. 7-24 A, The Kessler technique for tendon repair: 4–0 nylon is used. A running suture of 6–0 nylon is added. B and C, Simple horizontal mattress sutures may be used instead of the Kessler technique.

Partial lacerations consisting of greater than one third of the tendon should also be repaired. Small “nicks” can usually be left alone.

Spontaneous rupture of extensor tendons can also occur in patients with rheumatoid synovitis or following wrist fractures. When this occurs, it can mimic a peripheral nerve entrapment.

FLEXOR TENDON INJURIES

Flexor tendon injuries are diagnosed by history and examination. Partial or complete loss of finger flexion is accompanied by a typical posture of the finger (Fig. 7-25). There are often associated digital nerve injuries. Repair of flexor tendon injuries is a complex problem that should be undertaken only in the operating room by an experienced surgeon. Primary repair of these injuries is indicated when the laceration occurs distal to the sublimis insertion or proximal to the distal palmar crease. Primary tendon repair between these two points, in so-called no-man’s land, is frequently unrewarding because adhesions are likely to form between the lacerated tendon ends and the flexor sheath and pulleys (Fig. 7-26). In selected cases of sharp wounds, primary tendon repair may be undertaken in this area. Otherwise, simple closure of the skin laceration followed by secondary tendon grafting in 6 to 8 weeks is often preferable.

Fig. 7-25 A, The position of rest. With the hand lying on a flat surface, the fingers will maintain a position of slight flexion. B, When the flexor tendon is lacerated, the affected finger will rest in extension.

Fig. 7-26 No-man’s land, the critical area of the annular ligaments.

Lacerations of the wrist that involve the palmaris longus tendon should always be carefully evaluated for median nerve injury because these two structures are close in this area.

Hand Infections

HUMAN BITES

These are common injuries that are often mistaken for innocuous lacerations. Serious complications and dis ability frequently result, however, usually from the inoculation of virulent oral bacteria into the wound. A variety of organisms may be involved, but the most common are mixed anaerobes and aerobes, streptococci, and Staphylococcus aureus. More than half of hospital admissions for hand infection are caused by human bites.

The usual mechanism of injury is a fist fight in which the clenched fist strikes the opponent’s tooth. Most commonly, the MCP joint of the index or long finger is involved. The injury may cause penetration of the tendon, MCP joint capsule, and even the metacarpal head. When the finger is extended, the site of injury is often obscured and obliterated. Thus, drainage is hindered, and infection is encouraged. (Laceration of the extensor tendon may also occur but is often overlooked because the finger is examined in the extended position.) The stage is set for spread of the infection into the joint and sometimes throughout the entire hand.

TREATMENT

Appreciation of the injury is most important so that the initial wound is properly treated. Always assume that puncture wounds on the dorsum of the IP or MP joints are clenched-fist injuries unless proven otherwise, and examine the hand with the fist clenched as well as extended. Thorough inspection, cleansing, and debridement are needed for all wounds except the most superficial. The laceration may need to be enlarged to fully visualize the extent of the wound. Cultures are taken, and the wound is left open. No structures are repaired. A wick may be placed in the wound, and a soft bulky dressing is applied. Tetanus prophylaxis is given. Antibiotics are administered on an empiric basis. Initially, they are given intravenously, followed later by the oral route. They are changed as needed, depending on the results of the initial culture and sensitivity.

If a wick is used, it is removed the next day, and daily wound cleansing and dressing changes are begun. The laceration is inspected closely, and if it is not improving, further surgical debridement and intravenous antibiotic therapy may be necessary. If the wound is healing satisfactorily, antibiotic coverage is continued for 2 to 3 weeks. Secondary closure of the wound is usually unnecessary. Complete extensor tendon lacerations may eventually require secondary repair, usually in 5 to 10 days when the wound is clean.

Wounds treated within a few hours can usually be managed on an outpatient basis. Older injuries may require hospitalization, because cellulitis and abscess formation are often well established. Roentgenograms are always taken to rule out fracture (or infection in late cases).

FELON

A felon is an infection of the closed space of the pad of the distal phalanx (Fig. 7-27). It occurs secondary to a local puncture wound and is characterized by rapidly increasing pressure and pain. The entire pulp of the fingertip is swollen, tense, and reddened. The swelling typically does not cross the distal flexion crease. Osteomyelitis of the distal phalanx and extension of the infection into the flexor sheath or adjacent joint may result. S. aureus is the most common offending organism. Early incision and drainage are indicated. A short 24-hour trial of conservative treatment with antibiotics and hot packs may be attempted, but if symptoms do not rapidly diminish, early drainage is advisable. A metacarpal block is adequate anesthesia. A tourniquet is applied to the base of the finger, and a direct incision is made into the point of maximum tenderness and swelling on the volar aspect of the pulp. The incision does not have to be any longer than 5 to 10 mm. If no specific “point” can be detected, a straight lateral incision, which may be extended around the tip of the finger, is made and extended down to bone (Fig. 7-28). The “fish-mouth” incision should not be used. A pack should be inserted that is removed in 2 days. Routine care of the wound after drainage includes dressing changes every 2 to 3 days and maintenance of antibiotic therapy. The wound is allowed to heal by secondary intention and usually heals within 2 weeks.

Fig. 7-27 Felon. The pus accumulates in the pulp of the distal phalanx.

Fig. 7-28 Drainage of a felon. The incision is placed posterior to the neurovascular bundle. Incisions in the thumb and small finger should be on the radial side. In the index, long, and ring fingers, the incision should be on the ulnar side.

PARONYCHIA

Paronychia is an infection of the distal phalanx that occurs along the edge of the nail. The organism, usually Staphylococcus, is often introduced by biting the nail or by a rough manicure (anything that breaks the seal between the nail plate and proximal nailfold). Local signs of infection, such as redness, swelling, and tenderness, are invariably present (Fig. 7-29).

Fig. 7-29 Paronychia. A, The abscess is present beneath the eponychium. B, The infection has penetrated under the nail and extended proximally.

Acute paronychia usually requires drainage, although oral antibiotics and local care occasionally result in a cure in 3 to 5 days. Once the pus has localized, incision and drainage are indicated. This is easily accomplished by passing a scalpel between the nail and the adjacent eponychium under local anesthesia (Fig. 7-30). If the infection has penetrated under the nail, a small portion of the lateral nail may have to be excised. Incision and drainage through the eponychium should be avoided.

Fig. 7-30 Drainage of acute paronychia. Under digital block, a scalpel blade is passed between the nail fold and the nail. This usually evacuates pus.

Once the infection spreads under the nail, a subungual abscess results. In this case, drainage is only effective if the proximal part of the nail is excised (Fig. 7-31). The nail usually regrows. Chronic paronychia is treated in a similar manner, although the organism involved is often Candida albicans, which may respond to topical antifungal agents. Dermatology referral may be needed in refractory chronic cases.

Fig. 7-31 Drainage of paronychia when a subungual abscess is present. Lateral incisions are made through the eponychium, and the base of the nail is removed. Packing is applied, and the eponychium is replaced but not sutured.

TENDON SHEATH INFECTIONS

Infection may occur inside a flexor tendon sheath from extension of a felon or directly from a puncture wound. The rapid increase in pressure because of the accumulation of pus may obliterate the blood supply to the tendon and result in necrosis and complete loss of function of the tendon. The infection may also spread through the rest of the hand. Early diagnosis and treatment are therefore important.

CLINICAL FEATURES

The patient with suppurative tenosynovitis is febrile and often in a toxic condition. The disorder can usually be diagnosed by the presence of the four cardinal signs of Kanavel: (1) the finger is uniformly swollen; (2) the finger is held in slight flexion for comfort; (3) intense pain is present on passive extension of the finger; and (4) marked tenderness is present along the course of the inflamed sheath.

TREATMENT

Early treatment with high doses of antibiotics, elevation, and splinting may result in a cure. In addition, wide incision and drainage are usually necessary to prevent sloughing of the tendon and further spread of the infection.

High-pressure injection wounds of the hand can cause severe infections. These occur when paint, oil, or grease is accidentally injected into the soft tissues of the hand. The puncture wound may be quite innocuous, but extensive debridement of devitalized tissue and decompression are necessary to prevent infection and avoid the need for amputation, which is necessary in 15% to 30% of cases. Paint appears to be the most toxic substance. Prompt recognition of the problem is important.

Fractures of the Forearm

Fractures in Adults

Fractures that occur through both bones of the forearm in adults are usually shortened and displaced (Fig. 7-32). Accurate reduction of these injuries by closed methods is difficult, and there is a strong tendency for these unstable fractures to angulate after swelling subsides, in spite of a good reduction and cast immobilization. Strong muscular forces acting across the fracture fragments predispose to this loss of correction. Consequently, there is a high rate of nonunion. For these reasons, displaced fractures of both bones of the forearm in the adult are often treated by primary open reduction and internal fixation. Closed treatment may be attempted, but if it is unsuccessful the first time, operative intervention is usually indicated. The length of immobilization is shorter with surgery, and there is a more rapid return of function. Undisplaced fractures of both bones are treated with a long arm cast for 8 to 12 weeks. Isolated fractures of either the radius or the ulna are treated in a similar manner. If enough angulation is present to interfere with rotation, closed reduction is attempted. If it is unsuccessful, open reduction and internal fixation are indicated. Undisplaced fractures are treated with a long arm cast for 8 to 12 weeks or until healing is complete.

Fig. 7-32 Roentgenogram of a fracture of both bones of the forearm in an adult that required primary open reduction with internal fixation because position could not be maintained with casting.

FRACTURES IN CHILDREN

Fractures in children differ from those in adults in that surgery is rarely necessary. Reduction is usually possible by manipulation with the patient under light anesthesia. Angulated fractures are reduced by traction and countertraction, with manual correction of the angulation. It is often necessary to break the opposite cortex of the greenstick fracture to prevent reangulation from occurring in the cast (Fig. 7-33). Displaced fractures are treated by reduction with traction and countertraction (Fig. 7-34). Slight “bayonet” apposition is acceptable in young children if the alignment is satisfactory because subsequent remodeling of growth corrects minor deformities. Children are examined at weekly intervals for 3 weeks to determine whether any reangulation of the fracture is occurring after the swelling subsides. If angulation does recur before 2 weeks pass, it can usually be corrected manually. However, if more than 2 weeks has passed, the healing is so rapid in children that the angulation may be permanent. The cast is worn for 7 to 8 weeks.

Fig. 7-33 A, Greenstick fracture of the forearm. The tension side of an angulated greenstick fracture of both bones of the forearm requently acts as a spring and may cause the angulation to recur. B and C, These fractures should be manually broken through to prevent recurrence. The periosteum on the concave side will remain intact. Reduction is then accomplished by simple traction.

Fig. 7-34 Reduction of a forearm fracture by simple vertical traction and countertraction. A, The fingers are incorporated into finger “traps.” Countertraction is applied with a weight or water bucket. B, A long arm cast is applied with the elbow flexed 90 degrees and molded into an oval shape and straight by placing the hands on the anterior and posterior sides. C, An improperly molded circular cast may allow the forearm bones to encroach on the interosseus space, which could limit rotation. D, A properly molded elliptical cast will prevent this from occurring.

All forearm fractures in children and adults are immobilized by a long arm cast with the elbow flexed 90 degrees. The forearm portion is always molded to prevent encroachment on the interosseous space.

TRAUMATIC BOWING OF THE FOREARM

This is an unusual clinical entity in which “plastic deformation” of the radius and/or ulna occurs in the absence of typical clinical and roentgenographic findings for fracture (Fig. 7-35). The usual cause is a fall on the outstretched hand. There may be a fracture of one bone and bowing of the other or, less commonly, bowing of both bones. Management of these injuries is controversial. Persistent angulation could limit pronation and supination, although young children (younger than 5 years) will undergo bone remodeling and probably do not need reduction. An angulated fracture of one bone is also difficult to reduce until the bowing of the other bone is corrected. In older children, the angulation should be corrected. The reduction may require significant force, and general anesthesia is usually needed. These patients should always be referred for an orthopedic consultation.

Fig. 7-35 A, Traumatic bowing of the radius (arrow). B, Fracture of the ulna with bowing of the radius.

GALEAZZI FRACTURE–DISLOCATION

This injury is a fracture of the shaft of the radius with a dislocation of the distal radioulnar joint (Fig. 7-36). It is rare in children. The disorder is sometimes called the reverse Monteggia fracture. Usually, the radius is fractured in its distal third, and the radioulnar disruption is often missed. Surgery is usually required for repair.

Fig. 7-36 Galeazzi fracture–dislocation. There is a fracture of the distal portion of the radius with shortening. This shortening can only occur if there is injury elsewhere (in this lesion, a radio-ulnar dislocation). On the lateral view, the distal portion of the ulna is usually dislocated dorsally.

Fractures of the Wrist

Several common injuries occur in the region of the wrist joint: Colles’ fracture, fracture of the distal portion of the radius in children, epiphyseal fractures of the distal aspect of the radius, and fractures of the scaphoid. Treatment of all these injuries is very similar.

COLLES’ FRACTURE

Colles’ fracture is the most common injury of the wrist. It usually results from a fall on an outstretched hand. The force of the fall fractures the distal portion of the radius and displaces it into the typical “silver-fork” position. In addition to the dorsal angulation, there is shortening and radial deviation of the distal fragment (Fig. 7-37). There is usually an associated injury to the ulnar styloid or ulnar collateral ligament of the wrist. The fracture can usually be reduced under local anesthesia if reduction is performed within a few hours. If more time passes, a general anesthetic may be necessary, because the local anesthetic may not diffuse through the clotted hematoma after several hours have passed. The tip of the ulna should also be injected.

Fig. 7-37 A and B, Typical Colles’ fracture with dorsal and radial displacement. Normally, the tip of the styloid process of the distal portion of the radius extends 1 cm distal to the tip of the ulnar styloid. The articular surface of the lower part of the radius inclines 25 degrees ulnarward and 10 degrees volarward. C and D, Following complete reduction, the length and these angular relationships are restored.

With the assistant grasping the forearm for countertraction, the surgeon grasps the hand of the affected wrist (Fig. 7-38). The thumb of the surgeon’s other hand is placed over the distal fragment, and the wrist is hyperextended to break up any impaction. Traction and countertraction are then applied, and by using the thumb for pressure on the distal fragment, the rotation is corrected, and the dorsal cortex of the distal fragment is forced onto the dorsal cortex of the proximal fragment (see Chapter 2). Ulnar and volar pressure over the distal fragment will then correct the radial and dorsal angulation. The radial styloid is palpated to determine whether the length has been restored. With the assistant maintaining volar and ulnar tension on the hand, a well-molded cast is applied with the wrist slightly pronated. The cast is well molded over the dorsal and radial aspects of the distal fragments and the volar aspect of the proximal fragment to keep the dorsal soft tissue tight. A short arm cast is usually sufficient. Excessive volar flexion of the wrist should be avoided and is unnecessary if the cast is properly applied and molded. Excessive flexion of the wrist may cause median nerve compression. The base of the thumb may be included to the IP joint to help prevent radial collapse.

Fig. 7-38 Reduction of Colles’ fracture. A, The needle is inserted dorsally into the fracture hematoma, and 5 to 10 mL of local anesthesia is injected. B, The distal fragment is disimpacted, and longitudinal traction is applied. Thumb pressure is then applied to the distal fragment to correct the dorsal displacement. C, The radial displacement is corrected by further digital pressure and ulnar deviation of the wrist. D, Upward pressure on the proximal fragment and tension on the slightly flexed, ulnarly deviated hand will maintain the reduction. A cast is then applied and properly molded.

Adapted from Compere EL, Banks SW, Compere CL: Pictorial handbook of fracture treatment, ed 5, Chicago, 1963, Year Book Medical Publishers Inc.

An alternative method of treatment is to use the method of traction previously described for forearm fractures. After anesthesia has been obtained, the fracture is disimpacted, and the patient’s index finger and thumb are placed in the finger traps. A counterweight is placed on the upper part of the arm, and the fracture is manipulated. A properly molded cast is then applied with the forearm in slight pronation. Roentgenograms are then repeated.

If the reduction is satisfactory, the wrist is elevated, and ice is applied for 48 to 72 hours. Active motion of the fingers is encouraged, and the roentgenogram is repeated in 7 to 10 days. The fracture is immobilized for approximately 6 weeks.

After the cast is removed, some temporary stiffness should be expected for several weeks. This usually subsides gradually as the activity level is increased. A temporary splint that is removed several times a day for exercise is frequently helpful in the transition period between cast removal and full use of the extremity.

Occasionally, some loss of reduction may occur in a week or two after the swelling subsides in the cast. This is particularly true if there is comminution of the dorsal cortex. In the elderly patient, this position should be accepted rather than attempting to remanipulate the fragments to improve the roentgenographic appearance. This would only lead to more swelling, stiffness, and loss of function. Accepting the minor cosmetic deformity caused by the slight malunion is preferable in the older patient. If this occurs in younger patients (especially radial shortening), remanipulation with pinning or the application of an external fixator is indicated.

SMITH’S FRACTURE

This fracture has often been called the reverse Colles’ fracture (Fig. 7-39). One form of this fracture may be considered as such. The type that does not involve the articular surface may be treated by traction, manipulation, and casting in supination. Treatment in supination is important. “Cocking up” the wrist (the reverse of the Colles’ treatment) will frequently not hold the reduction. One type of Smith’s fracture has an articular component that results in volar subluxation of the carpal bones. This injury often requires open reduction with internal fixation for satisfactory results.

Fig. 7-39 Smith’s fracture. Closed reduction is usually successful with the type that does not involve the articular surface (A), but surgery is usually necessary for the intraarticular type (B).

BARTON’S FRACTURE

This is an oblique fracture that is essentially the reverse of the intraarticular Smith’s fracture. The injury involves an oblique dorsal rim fracture–dislocation through the articular surface of the distal portion of the radius. Because this fracture involves the joint surface, accurate reduction is necessary, and open reduction is often required.

FRACTURE OF THE DISTAL RADIUS IN CHILDREN

In children and adolescents, a fracture may occur through the distal radial epiphysis. If it is displaced or angulated over 15 to 20 degrees, it is reduced in the same manner as Colles’ fracture and immobilized in a well molded cast for 5 weeks. Reontgenograms should always be repeated at 7 to 10 days to be certain that loss of position has not occurred. If the fracture is undisplaced, the diagnosis may be difficult. It should be kept in mind, however, that sprains of the wrist are very rare in children because the epiphyseal plate is weaker than the surrounding ligamentous structures, and trauma will usually produce an epiphyseal fracture rather than a ligamentous sprain. Clinical tenderness over the epiphysis is highly suggestive of a fracture, and a short arm cast should be applied to these injuries for 2 weeks even though the roentgenographic findings may be normal. If a healing callus is present at the end of 2 weeks, the cast is continued for an additional 2 weeks. If no callus is present, the cast is removed, and the “sprain” has had excellent treatment. Fractures of the distal portion of the radius also occur in children approximately 2.5 cm above the wrist joint. They are treated in the same manner as Colles’ fracture. Undisplaced or so-called torus fractures also occur in this area (Fig. 7-40). No displacement occurs with this injury, but it should be immobilized in a short arm cast for 3 weeks.

Fig. 7-40 The “buckle” or torus fracture of the distal portion of the radius.

FRACTURES OF THE SCAPHOID

The scaphoid is the carpal bone that is most prone to fracture (Fig. 7-41). This injury also occurs as the result of a fall on the outstretched hand. The blood supply to this bone frequently enters the distal portion. Consequently, fractures that occur through the midportion of the bone may lead to avascular necrosis of the proximal fragment. This complication almost always occurs in more proximal fractures. Nonunion is also more frequent following this injury. These fractures are important because a delay in the diagnosis can contribute to the risk of nonunion.

Fig. 7-41 Fractured scaphoid (arrow).

The diagnosis is sometimes difficult. It should be suspected, however, in any patient with a history of a “sprained wrist” who has persistent swelling and pain in the wrist. Clinically, tenderness and swelling in the anatomic snuffbox are characteristic findings.

Initial roentgenographic findings are often normal because there may be little or no displacement of the fracture fragments. The fracture usually becomes visible in 2 to 4 weeks, however, as decalcification around the fracture line occurs.

Whenever this injury is suspected by history and physical examination, even if the radiograph looks normal, a short arm cast including the thumb should be applied. The roentgenogram is repeated in 2 to 3 weeks. If a fracture line becomes visible confirming the diagnosis, the immobilization is continued until complete healing has occurred, which may take 2 to 3 months. If pain persists but the roentgenogram remains normal, MRI, computed tomographic (CT), or bone scanning is indicated.

The type and length of immobilization used in the treatment of the acute nondisplaced navicular fracture is controversial, but a short arm thumb spica cast for 8 to 12 weeks is usually recommended. Failure of the fracture line to fill in by this time may indicate the need for surgery.

Displaced or angulated fractures often require open reduction and internal fixation and should be referred.

THE SPRAINED WRIST

Although simple, uncomplicated ligamentous injuries of the wrist do occur, there are a number of conditions that are often misdiagnosed as sprains. Failure to appreciate and properly treat these disorders can lead to permanent disability and chronic pain. Among the more common injuries presenting as “sprains” are the following:

1 Fractures of the navicular (usually caused by a fall)

2 Undisplaced epiphyseal fractures of the distal portion of the radius in children

3 Fracture of the hook of the hamate (often occurring when a baseball bat handle strikes the palm)

4 Avulsion fractures of the triquetrum, an injury that may signify serious ligamentous disruption (Fig. 7-42)

5 Carpal instability, frequently manifested by scapholunate dissociation, a separation of lunate from the scaphoid that may require surgery

6 Subluxation of the distal ulna (usually resulting from complete ligamentous rupture between the ulna and its attachments to the radius and carpal bones)

Fig. 7-42 A, Avulsion fracture of the triquetrum (arrow). B, Scapholunate dissociation (arrow). Note the widening between the scaphoid and lunate. C, Dislocation of the distal ulna.

Careful clinical palpation usually reveals the site of injury. Routine wrist roentgenograms are always performed, and special views are added as indicated.

The true simple sprain is well treated by light immobilization for 10 to 14 days followed by reevaluation and further testing as indicated. Elastic wraps or “light braces” are inadequate. Patients with more serious fractures or ligamentous disruptions should be referred.

Fractures of the Hand

The principles of treatment of finger injuries are similar to other fractures except that the reduction must be more accurate in the hand. With certain exceptions, manipulation and external immobilization constitute satisfactory treatment. Principles of treatment include the following:

1 Avoid overimmobilization.

2 Be certain to correct rotational as well as angular malalignment.

3 Early surgery in the form of open reduction and internal fixation is often more “conservative” than are overzealous manipulation and prolonged, improper splinting.

4 Fingers should be immobilized in the position of moderate flexion. Avoid splinting the finger joints in extension, especially the MP joint (Fig. 7-43).

5 Displaced intraarticular fractures involving greater than 25% of the joint surface are unstable and usually require reduction and internal fixation (Fig. 7-44).

6 In the position of grasping, the axes of all flexed fingers point to the navicular bone (Fig. 7-45). Failure to appreciate this fact may result in rotational malunion.

7 “Chip” fractures near joints usually have a tendon or ligament attached. These injuries require careful evaluation (Fig. 7-46).

Fig. 7-43 Collateral ligaments of the MCP joint. These ligaments are normally lax in extension and tight in flexion. Prolonged splinting in extension may allow them to shorten slightly, thereby making future flexion difficult.

Fig. 7-44 A, A displaced intraarticular IP joint fracture (arrow). Open reduction with internal fixation (B), was required.

Fig. 7-45 Normally, the axes of the flexed fingers point to the navicular (dot). Malunion with rotation will cause the fingers to overlap when a fist is made. The resultant functional disability may be great.

Fig. 7-46 Collateral ligament avulsion fracture, which usually causes instability.

FRACTURES OF THE METACARPAL

Fractures of the shaft of the finger metacarpal often present with dorsal angulation because of the action of the interosseous muscles (Fig. 7-47). Fractures that are in good alignment and apposition will heal satisfactorily in 3 to 4 weeks. Slight shortening less than 4 to 5 mm may be accepted. A short arm ulnar or radial “gutter” splint or a volar splint incorporating an aluminum splint and extending over the finger provides adequate immobilization.

Fig. 7-47 A, Fracture of the metacarpal. B, Reduction is maintained by a metal splint incorporated in a cast or plaster splint.

Fractures of the neck of the metacarpal are common in the small finger (Fig. 7-48). These commonly occur in fist fights and are sometimes called “boxer’s fractures.” Clinically, there is swelling over the fracture site and depression of the “knuckle” of the affected finger. Impacted, stable fractures with minimal angulation are treated with a compression dressing for 1 week followed by gradually increasing active exercises. Radiographs are repeated in 1 week to assess position. Minimally angulated unstable fractures are immobilized in an ulnar gutter splint incorporating the ulnar two fingers. Fractures with angulation greater than 25 to 30 degrees should be reduced and immobilized in a plaster or fiberglass gutter splint for 4 weeks. Even if fractures of the ring or small finger metacarpal necks heal with a mild amount of angulation, the functional result is usually good because of the high mobility of the carpometacarpal (CM) joints of these fingers. However, the patient must be warned that the “knuckle” will never be as prominent when a fist is made. The same fracture in a small child will usually correct itself with further growth if the child is young enough. Open reduction is occasionally indicated in severely angulated fractures. Fractures of the index and long fingers are less forgiving than those of the ring and small fingers, and angulation of 15 degrees may require reduction. These should probably be referred if there is any doubt about the alignment.

Fig. 7-48 A, Fracture of the small finger metacarpal (arrow). B, Reduction is obtained by digital pressure against the distal fragment with counterpressure on the dorsum of the proximal fragment. C and D, Applying and molding the ulnar gutter splint. E, The end result.

Bennett’s fracture is actually an intraarticular fracture-dislocation that occurs at the carpometacarpal joint of the thumb (Fig. 7-49). The injury involves a large portion of the metacarpal base, creating instability. Because of the pull of the long abductor muscle that inserts at its base, the metacarpal is dislocated proximally, leaving a large fragment behind. Most of these injuries are displaced and require exact reduction and internal fixation to preserve the function of this important joint.

Fig. 7-49 A, Bennett’s fracture of the base of the thumb metacarpal. B, The roentgenographic appearance.

A similar fracture-dislocation, sometimes called the “reverse Bennett,” occurs at the CM joint of the small finger (Fig. 7-50). Although not as potentially serious as the injury to the thumb, reduction and internal fixation are often required. Failure to recognize and properly treat this injury may lead to a weakness in grip because more power is provided by the ulnar side of the hand than the radial side.

Fig. 7-50 Fracture-dislocation of the small finger CM joint (arrow), sometimes called the “reverse Bennett” injury.

The Rolando fracture is a comminuted intraarticular fracture of the base of the thumb metacarpal (Fig. 7-51). It is frequently difficult to restore normal anatomic alignment to the fracture, even by open reduction. The prognosis for return of normal use of this joint following a Rolando fracture is often poor. Early referral is indicated.

Fig. 7-51 Rolando fracture.

The extraarticular fracture of the base of the thumb metacarpal is common (Fig. 7-52). Up to 30 degrees of angulation is acceptable. A thumb spica cast is applied for 5 weeks.

Fig. 7-52 Extraarticular fracture of the base of the thumb metacarpal.

FRACTURES OF THE PHALANGES

The treatment of phalangeal fractures is usually determined by the pattern of the fracture (transverse, oblique, or spiral) and whether or not the injury is stable. Undisplaced stable transverse fractures can be safely treated by buddy taping to the adjacent finger and splinting proximal to the MCP joint for 4 weeks. If the fracture is potentially unstable, the treatment is the same, but close follow-up with radiographs is important. Fractures of the proximal phalanx often angulate to the volar aspect of the hand (Fig. 7-53). This angulation is produced by the pull of the intrinsic muscles. Usually, the displaced transverse fracture can be converted to a stable injury. Reduction is usually possible by traction on the flexed finger toward the tubercle of the scaphoid. Immobilization in moderate flexion with a splint for 4 weeks is usually sufficient time for healing to occur. Close follow-up is required. (Transverse fractures tend to angulate after reduction, and spiral fractures tend to rotate and shorten.) Immobilization for 4 weeks is sufficient for healing of these fractures, and protection beyond 4 weeks can lead to stiffness.

Fig. 7-53 A, Fracture of the proximal phalanx. B, Reduction by flexion of the distal fragment. The position is maintained by a splint.

Undisplaced spiral and oblique fractures can be treated by splinting. Those that are displaced have no inherent stability when reduced and usually require internal fixation to maintain reduction (Fig. 7-54). Oblique fractures of the proximal phalanx are a common cause of rotational malunion; prevention of this deformity must always be kept in mind when treating these injuries. Unstable displaced fractures usually require open reduction and internal fixation.

Fig. 7-54 Oblique fracture of the proximal phalanx with malrotation. Always evaluate for proper rotation.

The common epiphyseal fracture of the base of the proximal phalanx of the small finger is usually a type II Salter fracture and is usually displaced into abduction (Fig. 7-55). It is reduced with the patient under local anesthesia by applying traction with the finger in slight flexion and then adducting the finger against a pencil or the physician’s finger, which acts as a fulcrum. It is taped to the ring finger and immobilized with a padded splint for 3 to 4 weeks.

Fig. 7-55 A, Epiphyseal fracture of the proximal phalanx of the small finger in the typical position of ulnar deviation. B, Reduction by traction and pressure against the finger in the web space.

Fractures of the middle phalanx may angulate volarward or dorsally (Fig. 7-56). Traction with manipulation of the fracture will usually effect a reduction. The finger is splinted for 4 weeks.

Fig. 7-56 Fracture of the middle phalanx. If the fracture is proximal to the insertion of sublimis tendon, the fracture will tend to angulate into flexion (A). This fracture may require treatment in slight extension. Fractures distal to the sublimis insertion (B) frequently angulate into extension, and flexion is therefore required for reduction.

Dislocations of the Fingers

MP dislocations are not common and are most likely to involve the thumb. They may be classified as simple or complex. Simple dislocations may be reduced by traction and manipulation (Fig. 7-57). If the MP joint is stable after reduction, buddy taping to the adjacent finger for 2 to 3 weeks is usually sufficient. If it is unstable, referral is indicated. Most dislocations involving the thumb are simple.

Fig. 7-57 An MP dislocation that may be reduced by simple traction and digital pressure.

Dislocations of the fingers are more likely to be complex. These dislocations usually have soft tissue interposed in the joint, or the metacarpal neck is buttonholed through a window in the soft tissue (Fig. 7-58). It is usually impossible to treat them by closed methods. Some improvement may seem apparent after the attempted reduction, but the joint does not “snap” back into place and does not feel reduced. Reduction of the complex MP dislocation is prevented by the soft tissue interposed between the surfaces or tightened around the metacarpal head. The more traction and pressure applied to the finger, the tighter the soft tissue becomes. Open reduction is usually necessary.