CHAPTER 7 The hand
Note that the separation of conditions into those affecting the wrist and those affecting the hand has been done for convenience, and that in many cases examination of both regions is necessary.
Dupuytren’s Contracture
In this condition there is nodular thickening and a contracture of the palmar fascia. The palm of the hand is affected first, followed at a later stage by the fingers. The ring finger is most frequently involved, followed by the little and middle fingers. The index and even the thumb may be affected. In some cases there is corresponding thickening of the plantar fascia. The progressive flexion of the affected fingers interferes with the function of the hand and may be so severe that the fingernails dig into the palm. The condition mainly affects men over the age of 40. There is a definite genetic predisposition in 60–70% of cases, and in some cases there may be an association with epilepsy, diabetes or alcoholic cirrhosis. There is a distinct geographical distribution: it is rare in Africa, India and China. Below the age of 40, and in either sex, its onset may be precipitated by trauma. Under these circumstances it may pursue a particularly rapid course.
As far as treatment is concerned, a waiting policy may be pursued if the condition is confined to the palms. When the fingers are affected surgical treatment is usually advised, but this is complicated by a number of factors. If the fingers have been held in a flexed position for a long time, secondary changes in the interphalangeal joints may prevent finger extension even after the involved tissue has been removed. In the case of the little finger, amputation in these circumstances may be the best line of treatment. The digital nerve sheaths may blend with the fascia so that dissection is tedious and difficult; involvement of the skin may necessitate Z-plasties or other plastic procedures; and the patient’s age and general health may be adverse factors. In most cases wide excision of the affected fascia is advised. When this is not possible, improvement in function, often lasting for some years, may follow simple division of the contracted fascia in the palm.
Vibration Syndromes
Prolonged exposure to high-frequency vibration (such as may be experienced from the use of jack hammers or hand-held buffing, riveting and caulking machines) may affect bone, nerves and blood vessels. Bone is rarely affected to a significant degree, but new bone formation and hairline fractures (which are slow to heal) are sometimes seen. Involvement of the peripheral nerves may lead to pain and paraesthesia, numbness, tremor, loss of fine touch sensation, proprioception and discrimination. There may be muscle denervation and weakness involving especially the small muscles of the hand. In the case of the peripheral blood vessels there is disturbance of their autonomic control, and the arterioles of the hand become hypersensitive to cold and vibration. In the typical case there are attacks in which one or more fingers turn white on exposure to cold (‘episodic blanching’), with reactive hyperaemia on warming; and there is usually associated discomfort and clumsiness of the hand during attacks. As the condition progresses more fingers become involved, incidents occur both in summer and in winter, and hand function becomes permanently disturbed. The hand becomes weak and clumsy, and with impaired sensation and proprioception the patient has difficulty in dressing (e.g. doing up buttons and shoelaces), handling small objects (e.g. coins, nuts and screws), and carrying out many other tasks (e.g. tying fishing hooks). The differential diagnosis includes Raynaud’s disease, cervical rib and the costoclavicular syndrome, cervical spondylosis, and sensitivity to β-blockers.
There are a number of classifications of the stages of the condition, and the long-established Taylor–Pelmear scale is still widely used (Table 7.1). Well established cases are recognised as one of the prescribed diseases under the Social Security Act, and the qualifying criteria are clearly stated. (The condition must occur throughout the year, involve at least three fingers of one hand (with the middle and/or proximal phalanges being affected), and be due to exposure to vibrating tools.) No treatment is effective, but deterioration may be slowed or prevented by avoiding further exposure to vibration.
Table 7.1 The Taylor–Pelmear scale
| Stage | Condition of digits | Work and social interference |
|---|---|---|
| 0 | No blanching of digits | No complaints |
| 0T | Intermittent tingling | No interference with activities |
| 0N | Intermittent numbness | No interference with activities |
| 1 | Blanching of one or more fingertips, with or without tingling or numbness | No interference with activities |
| 2 | Blanching of one or more fingers, with numbness; usually confined to winter | Slight interference with home and social activities; no interference at work |
| 3 | Extensive blanching. Frequent episodes, summer and winter | Definite interference at work, at home, and with social activities. Restriction of hobbies |
| 4 | Extensive blanching. Most or all fingers affected. Frequent episodes, summer and winter | Occupation changed to avoid further exposure to vibration because of severity of signs and symptoms |
Tendon and Tendon Sheath Lesions
See also under Rheumatoid arthritis.
Mallet finger
In a mallet finger the distal interphalangeal joint is held in a permanent position of flexion; the deformity may be moderate or complete. The patient is unable to extend the distal joint of the finger, either not at all or only incompletely. The problem is that the extensor tendon, usually as a result of trauma, either ruptures close to its insertion in the distal phalanx, or it avulses its bony attachment. Healing may occur spontaneously over a 6–12-month period, but it is usual practice to treat these injuries for 6 weeks with a light splint that holds the distal interphalangeal joint in extension.
Mallet thumb
Delayed rupture of the extensor pollicis longus tendon may follow Colles’ fracture (see Ch. 6) or rheumatoid arthritis, and repair by tendon transfer (using extensor indicis proprius) is usually advised. If the tendon is damaged by an incised wound, repair by direct suture is undertaken.
Boutonnière deformity
Flexion of the interphalangeal joint of a finger with extension of the distal interphalangeal joint characterises this deformity, which is due to detachment of the central slip of the extensor tendon which is attached to the base of the middle phalanx. This may follow incised wounds on the dorsum of the finger and avulsion injuries, but is more commonly seen in rheumatoid arthritis. Surgical repair of the extensor band is often undertaken for isolated lesions of this type.
Extensor tendon division in the back of the hand
Extensor tendons divided by wounds on the back of the hand carry an excellent prognosis and are treated by primary suture and splintage for approximately 4 weeks.
Profundus tendon injuries
Trigger finger and thumb
This condition results from thickening of a fibrous tendon sheath or nodular thickening in a flexor tendon.
In young children the thumb is held flexed at the metacarpophalangeal (MP) joint, and a nodular thickening in front of the MP joint is palpable; not infrequently the deformity is wrongly considered to be congenital in origin and untreatable.
In adults, the middle or ring finger is most frequently involved. When the fingers are extended the affected finger lags behind and then quite suddenly straightens. Nodular thickening, always at the level of the MP joint, may also be palpable. Division of the sheath at the level of the MP joint gives an immediate and gratifying cure, although it should be noted that in children spontaneous resolution occurs in more than 60% of cases.
Rheumatoid Arthritis
Rheumatoid arthritis, as is well known, very frequently affects the hand, and as it progresses may involve joints, tendons, muscles, nerves and arteries, producing most severe deformities and crippling effects on hand function.
In the earliest phases the hands are strikingly warm and moist; later the joints become obviously swollen and tender. Synovial tendon sheath and joint thickening, with effusion, muscle wasting and deformity, then becomes apparent. Tendon ruptures and joint subluxations are the main factors leading to the more severe deformities.
Surgery of the rheumatoid hand is highly specialised, requiring particular skills and experience in judgement, timing and technique, and is difficult to summarise with any accuracy.
In the earliest stages of the disease, medications which have analgesic, anti-inflammatory and antiautoimmune effects may be prescribed, with the judicious use of physiotherapy and splintage to alleviate pain, preserve movement and minimise deformity. When there is much synovial thickening at a stage before joint destruction has advanced, synovectomy is often helpful in alleviating pain and delaying local progress of the condition. In a few well selected cases, where there is severe joint destruction and progressive deformity, joint replacement may be helpful; some cases of major tendon involvement may benefit from repair and other procedures.
Osteoarthritis of the Interphalangeal Joints
Nodular swellings situated dorsally over the bases of the distal phalanges (Heberden’s nodes), or less commonly over the bases of the middle phalanges (Bouchard’s nodes), are a sign of osteoarthritis of the finger joints. They occur most frequently in women after the menopause, and are often familial. They are not related to osteoarthritis elsewhere. In many cases they are symptom free, but they may be associated with progressive joint damage which does cause pain.
Carpometacarpal Joint of the Thumb
Osteoarthritic changes are common between the thumb metacarpal and the trapezium, and they may give rise to disabling pain and impaired function in the hand. There may on occasion be a history of a previous Bennett’s fracture, or of occupational overuse. Several surgical procedures (e.g. excision of the trapezium) are available which give relief of pain, sometimes at the expense of some functional loss.
Tumours in the Hand
Tumours in the hand are not uncommon. Most involve the soft tissues and are simple, but it need hardly be stressed that where the diagnosis is uncertain a full investigation is essential. Among the commonest tumours are the following:
Infections in the Hand
These three common infections are treated along well established lines, using antibiotics and surgical drainage if pus has formed.
Fig. 7.A. Some potential sites of infection in the hand and fingers. S = synovial tendon sheaths; U = ulnar bursa; R = radial bursa; M = midpalmar space; T = thenar space. Note: C = communication between the radial and ulnar bursae.
