Fractures of the Radial Head

(Canada—Canadian Family Physician, September 2000, p. 1759.) The radial head can be fractured by a direct blow, but is more commonly injured by a fall on the outstretched hand with the forearm in supination. The resulting force probably causes damage by impact of the radial head on the capitulum. Palpation shows maximal tenderness 2 to 3 cm distal to the lateral epicondyle when the elbow is at 90 degrees flexion. Examination of radial head fracture usually also reveals joint effusion and reduced range of motion in all directions. Collateral ligament injury is commonly associated with radial head fracture. Fractures of the scaphoid and capitulum are likely to result from the same mechanism of injury. Anteroposterior or oblique radiographs may show the fracture, but a change in the posterior fat pad may be the only radiographic sign of damage to the radial head. Treatment depends on the type of fracture, but in all cases prolonged immobilization of the elbow must be avoided because of the danger of flexion contractures. In type I fractures, there is little displacement or involvement of bone margins and treatment includes slings, ice and analgesia with mobilization as soon as tolerable. While the treatment of type II radial head fractures is controversial, many experts recommend closed treatment and early mobilization, with aspiration of hemarthrosis and injection of anesthetic. Type III fractures are comminuted fractures of the entire radial head and require excision of the bone fragments with or without insertion of a prosthesis.

Understanding and Assessing Chronic Pain

(Hong Kong—The Hong Kong Practitioner, July 2000, p. 345.) Chronic pain is devastating and demoralizing and causes numerous adverse effects, including insomnia, anxiety, impaired concentration and depression. The three main types of chronic pain are nociceptive (visceral and somatic), neuropathic and muscle spasm. Visceral pain originates in hollow organs and frequently presents as colic. Somatic pain originates in tissues such as muscle, bone or skin. Neuropathic pain, which originates in the central or peripheral nervous system, is under-recognized as a cause of chronic pain. Muscle spasm may present as tension headache or shoulder girdle muscle pain and is often related to anxiety and stress. Spinal column pathologies can cause muscle spasm in the paravertebral muscles. Taking a detailed history may be sufficient to identify the source and extent of pain, especially if the physician uses a systematic pain questionnaire. Numerical ratio scales, visual analog scales and verbal descriptor scales have been developed to measure the severity of pain. There are also three pain assessment instruments commonly used: the memorial pain assessment card, the Wisconsin brief pain inventory and the McGill pain questionnaire.

Geographic Choroidopathy

(Canada—Canadian Family Physician, October 2000, p. 1977.) Geographic choroidopathy is a rare cause of decreased vision in adults. Although the condition is usually bilateral, patients may present with decreased vision in one or both eyes. Ophthalmoscopic examination shows typical atrophy near the optic disc, which gives the appearance of yellow-gray patches that progress to serpentine areas without pigment. As the affected area expands and the macula becomes involved, vision is reduced. The condition is relentlessly progressive and 20 percent of patients have less than 20/400 vision. The cause of geographic choroidopathy is unknown, but it is associated with autoimmune conditions and tuberculosis. Patients with geographic choroidopathy have an increased prevalence of HLA-B27. Treatment is usually based on systemic steroids and regular follow-up.

Safety of Drugs During Breast-feeding

(Canada—Canadian Family Physician, September 2000, p. 1753.) Relatively few drugs taken by breast-feeding mothers pose clinically significant risks to their infants. Because even low doses of chemotherapeutic agents are highly toxic to infants, most anticancer drugs are considered incompatible with breast-feeding. The anticonvulsive drugs that are most likely to be excreted in breast milk are phenobarbital, ethosuximide and primidone. Exposed infants have shown symptoms of sedation and withdrawal. Drugs of abuse, including alcohol, amphetamines and marijuana, should be avoided by nursing women because of possible symptoms in breast-fed infants. The use of ergot alkaloids is generally not advised during lactation, but this recommendation is based on a report of ergotism in an infant in a 1934 study and has not been confirmed by more recent detailed studies. Other drugs that should be used with caution during lactation include amiodarone, cyclosporine, lithium, estrogens and radiopharmaceuticals. While cigarettes are not often regarded as a drug, smoking may be the most common exposure to avoid during lactation.