What are Hand Problems?

Injuries and conditions of the hand and wrist present frequently. A knowledge of the anatomy and a few basic facts will assist the GP in identifying those patients who require referral and those who can be managed in practice.

Conditions that affect the hand and wrist will make patients present to their doctors because of pain, functional disability and concern over appearance.

* Ganglion Ganglia are most commonly found around the wrist, and may be either dorsal or volar.

Dorsal ganglia (see figure 1 in hard copy) most commonly arise from within the wrist joint and are filled with a straw-coloured jelly. They rarely give rise to pain.

Once the diagnosis has been made and the patient reassured, a decision can be made as to whether or not treatment should be offered. Many patients are happy to be reassured and confidently informed of the diagnosis, but others will not be satisfied until the lump is no longer there.

It is important to inform patients that all treatments have a substantial recurrence rate. Simple aspiration with a wide bore needle after anaesthetising a small area of skin will confirm the diagnosis by inspection of the typical contents. It will also result in immediate disappearance of the swelling.

However, a large number of aspirated ganglia will recur (up to 80 per cent in some series), often within a few days. There is no evidence to support the injection of steroid into the empty cavity in an attempt to reduce recurrence.

Excision of the ganglion under regional or general anaesthetic is accompanied by a significantly lower recurrence rate of around 10-20 per cent. This is still substantial and would be considered unacceptable for many surgical procedures.

Further, surgical excision will always be accompanied by a scar that will be permanent. Scars may be tender for some time, and there may be small areas of numbness in the skin distal to the incision.

Volar wrist ganglia arise from the wrist joint, the basal joint of the thumb or the tendon sheath of flexor carpi radialis in equal proportions. Aspiration of these ganglia must avoid the radial artery that often overlies the swelling.

Excision of a volar wrist ganglion will require a potentially long scar in order to trace the swelling's pedicle to its origin.

* Carpal tunnel syndrome The carpal tunnel is found at the base of the palm. It begins at the wrist flexion crease and extends distally for approximately 3cm. The tunnel's walls and floor are formed by the carpal bones, and its roof is formed by the flexor retinaculum, a thick fibrous sheet designed to bind down the flexor tendons as they contract, and prevent bowstringing.

The median nerve passes through the carpal tunnel. Its sensory fibres give sensibility to the thumb, index, middle and (usually) the radial half of the ring finger. The motor fibres of the median nerve innervate the muscles of the thenar eminence via the recurrent motor branch.

The symptoms of carpal tunnel syndrome therefore have both sensory and motor aspects. Patients mostly present with tingling (sometimes painful) in the innervated fingertips, which may be more severe at night. They may complain of clumsiness since they will be unable to feel the objects they try to manipulate.

Examination of the hand will often reveal muscle wasting (often of the short thumb abductor). Signs of excitability of the `compressed' nerve include a Tinel's phenomenon, where percussion over the nerve at the wrist results in paraesthesia being experienced in the distribution of the nerve (that is, at the fingertips), or a positive Phalen's test, where flexion of the wrist results in fingertip paraesthesia within one minute.

Nerve conduction studies are helpful in differentiating those patients who suffer from paraesthesia originating from root entrapment in the cervical spine from a more peripheral entrapment.

The cause of carpal tunnel syndrome is not normally obvious, and the recognised associations are with diabetes mellitus, rheumatoid arthritis, thyroid disease and pregnancy.

Treatment consists of splintage (particularly for night symptoms), oral diuretics or steroid injection into the tunnel. These methods will often only temporarily relieve symptoms. Surgical release of the roof of the tunnel under local anaesthesia is a quick, simple and reliable method of treatment. It is, however, essential to fully visualise and release the entire tunnel roof. Complications are unusual, although the scar may be tender for some weeks.

* Trigger finger The flexor tendons, which bend the fingers, pass through a tunnel that begins at the level of the distal palmar crease and ends at the distal interphalangeal joint. The covering of the tendon and the lining of the tunnel consist of synovium, a richly vascular structure that is subject to inflammation and subsequent swelling. This can lead to a mismatch in the size of the tendon and the mouth of the tunnel.

Parts of the tendon that are naturally wider and/or thicker can exit the mouth of the tunnel as the finger bends, but cannot easily re-enter the tunnel as the finger straightens. This results in a `clicking' sensation on straightening the finger, or - at worst - sticking of the finger in flexion, often described as `locking'.

Trigger fingers occur more frequently in diabetics and those with rheumatoid arthritis.

Treatment consists of injection of steroid into the flexor sheath (either through the palmar skin over the proximal phalanx, or at the mouth of the tunnel), and is successful in most cases.

Resistant or recurrent cases can be treated by sectioning the roof of the first part of the tunnel under local anaesthetic. Great care must be taken to preserve the digital nerves that run nearby.

Once released, the patient can actively test that a sufficient release has been performed by active finger flexion. Recurrence after surgery is rarely seen and usually represents an inadequate primary release.

* De Quervain's tendonitis The tendons that straighten the thumb - abductor pollicis longus (APL) and extensor pollicis brevis (EPB) - travel to the thumb base around the radial side of the wrist. They are contained within a short fibro-osseous tunnel to prevent them subluxating as the wrist bends and straightens. This first extensor compartment has a synovial lining to match the covering of the tendons, and this can also become inflamed. Pain is experienced on the radial side of the wrist as the thumb (or wrist) moves.

De Quervain's tendonitis most commonly occurs in females aged between 30 and 60 years. There is no known association with injury or work practices.

It is best diagnosed by palpation for tenderness over the first extensor compartment, often accompanied by swelling. Stretching of the tendons by asking the patient to firmly grip their own thumb in the palm (Finkelstein's test) is pathognomonic of the condition.

Treatment consists of rest and splintage in the first instance since most episodes are self-limiting. Resistant cases are offered an injection of steroid directly into the first extensor compartment. This will result in relief in most cases. Surgical division of the compartment can be performed, but this risks injury to the radial sensory nerve and painful subluxation of the tendons on movement of the wrist.

* Dupuytren's contracture The palmar fascia is a thin sheet of tissue that lies under the skin and extends into each finger. Susceptible individuals can develop lumps in the palmar fascia (see figure 2) that may contract, resulting in a loss of full straightening (extension). Flexion is not affected by Dupuytren's contracture, and the condition is rarely painful.

The commonest cause is thought to be a genetic predisposition, although smoking, diabetes, alcoholic liver disease and the use of vibrating machinery have also been implicated.

The decision to treat is based entirely on a complaint of a functional disability. Surgery cannot guarantee complete correction of the deformity, and stiffness and/or nerve injury can occur.

Patients must be informed that this is a life-long condition and it will recur after surgery if the patient lives long enough. Surgical release of the contracture, if performed carefully, will result in a dramatic improvement in function.

ASSESSMENT OF HAND INJURY

Injuries to the hand are common, particularly in the working male. A systematic examination of all structures in the hand will allow diagnosis to be made early and correct treatment to be initiated; however, failure to recognise all components of a hand injury risks permanent disability.

The components of the hand can be divided into:

* Skin (including the nails);

* Skeleton;

* Muscle (that is, tendons); and

* Nerves.

Skin injury can be laceration, partial loss (abrasion) or complete loss. Skin flaps are likely to survive if they have a wide proximal base. Narrow or distally based flaps are likely to necrose.

Skeletal injuries can be suspected if pain, crepitus or deformity is present. Assessing the rotation of the finger by examining the nail plane or the pattern of flexion will spot those fractures that are malrotated (see figure 3).

A knowledge of the movements provided by each of the flexor and extensor tendons will enable the examiner to recognise injury. An initial inspection of the posture of the digits may give clues to underlying injury (see figure 4).

There are two flexor tendons in each finger. Flexor digitorum superficialis (FDS) bends the proximal interphalangeal joint (PIPJ) when all the other fingers are held fully straight (see figure 5). Flexor digitorum profundus (FDP) bends the distal interphalangeal joint (DIPJ) when the proximal joint is held fully straight (see figure 6).

The extensor tendon straightens the proximal interphalangeal joint (by the central slip) and the distal interphalangeal joint (by a conjoining of both lateral slips). Division of the central slip results in a boutonniere deformity (flexion of the PIPJ with hyperextension of the DIPJ). Division of the conjoined lateral slips results in a mallet finger (with loss of active DIPJ extension).

Digital nerve injury results in sensory loss in the affected half of the finger pulp. Sweating will also be absent. Injury to a more proximal nerve trunk will result in both sensory and motor dysfunction. The innervation of each peripheral nerve should be revised before examination.

All hand injuries will result in swelling, which is compounded by dependency and can be controlled by early elevation with a sling.

Swelling results in stiffness and immediate loss of function, which can be permanent. In all cases it is essential that the initial management of all injuries to the hand includes strict elevation. Prompt referral for specialist examination if doubt exists will result in significantly better outcomes.

WORK-RELATED ARM PAIN

The recent past has seen an enormous rise in diagnoses of work-related arm pain. This is, however, an area of huge controversy, and strong opinions are held on both sides.

The increase in computer use by many sections of the population has been implicated by proponents as a causative, rather than provocative, factor. No evidence exists to relate computer use to arm pain, although poor posture is associated with neck and shoulder pain.

Certain work practices involving repetitive actions may exacerbate some hand conditions, but it is difficult to prove that those practices cause the condition.

Great care must be taken before diagnosing the controversial condition known as repetitive strain injury (RSI): many recognised hand conditions present with arm or hand pain on use, and strenuous efforts to diagnose these conditions must be made before introducing the possibility of RSI. It can be difficult to change this diagnosis once it has been made, and the individual may have difficulty in gaining subsequent employment.

CLINICAL FOCUS

* Ganglia are most commonly found around the wrist. Many patients are happy to be reassured and confidently informed of the diagnosis, but others will not be satisfied until the lump is no longer there. It is important to inform patients that all treatments have a substantial recurrence rate

* The symptoms of carpal tunnel syndrome have both sensory and motor aspects. Patients mostly present with tingling (sometimes painful) in the innervated fingertips, which may be more severe at night. They may complain of clumsiness since they will be unable to feel the objects they try to manipulate

* Trigger fingers occur more frequently in diabetics and those with rheumatoid arthritis. Treatment consists of injection of steroid into the flexor sheath (either through the palmar skin over the proximal phalanx, or at the mouth of the tunnel), and is successful in most cases

* De Quervain's tendonitis most commonly occurs in females aged between 30 and 60 years. There is no known association with injury or work practices. It is best diagnosed by palpation for tenderness over the first extensor compartment. Treatment consists of rest and splintage in the first instance since most episodes are self-limiting. Resistant cases are offered steroid injection directly into the first extensor compartment

* Flexion is not affected by Dupuytren's contracture, and the condition is rarely painful. The decision to treat is based entirely on a complaint of a functional disability. Surgery cannot guarantee complete correction of the deformity, and stiffness and/or nerve injury can occur

Copyright: CMP Information Ltd.

Record Number: A109291940

SOURCE:
The Practitioner.  Oct 8, 2003 p800.

Full Text: COPYRIGHT 2003 CMP Information Ltd.