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Discussion of the prevalence of osteomalacia in the elderly is complicated by the different definitions used and the fact that diagnostic criteria are rarely stated. In this study osteomalacia was defined as more than 25% of trabecular bone surface in an iliac crest biopsy sample covered with osteoid and a mean osteoid seam thickness of greater than 11 micron. All patients admitted to a geriatric unit over one year were screened and biopsy samples obtained from a high proportion. The estimated prevalence in this population was 3.7%; the prevalence was higher in women than in men and in those over 80 years than in those under 80.

Forty one elderly patients admitted to hospital for acute illnesses were also found to have subclinical osteomalacia. Immediately before discharge, therefore, all were randomised to receive either vitamin D2 25 micrograms daily, alfacalcidol 0.5 micrograms daily, or placebo. Treatment was given for at least three months, those allocated to placebo then being switched to an active drug. Within the first three months of treatment with either of the active drugs most patients had exhibited a fall to normal in osteoid values. In only four treatment periods was there a mild increase in serum calcium concentration, and in no patient was this accompanied by deterioration in renal function. Any increase in serum creatinine concentration was invariably attributable to the underlying disease for which the patient had been admitted in the first place. Subclinical osteomalacia in the elderly may be corrected by relatively low doses of alfacalcidol (0.5 micrograms daily) or vitamin D2 (25 micrograms daily) given for three months. Such treatment is safe and not accompanied by a serious risk of hypercalcaemia or renal impairment.

An elderly patient with nodular regenerative hyperplasia of the liver and hypothyroidism who presented with life-threatening bleeding from oesophageal varices is discussed. Progress has been uneventful following a semi-emergency portocaval shunt 5 years ago with no evidence of hepatic encephalopathy. This is presumably a tribute to the relatively well-preserved hepatic function in this condition.

Although osteomalacia is known to be common in some sections of the elderly population, the disease is often subclinical and there is uncertainty about the point at which treatment is necessary. Identification and treatment of osteomalacia are inseparably bound; the response of varying degrees of subclinical disease to treatment with vitamin D or alfacalcidol is described here. The response is assessed in relation to a simply derived reference range based on standard biochemical measurements together with a Jamshidi needle biopsy of the iliac crest. Although this technique does not define a truly normal range it identifies a treatable abnormality which could form the basis of further study of the problem of subclinical osteomalacia in the elderly.

Hypocalcaemia and hypophosphataemia either on admission or before discharge from hospital are poor discriminators for the presence of subclinical osteomalacia in the elderly. Reliance has to be placed on the measurement of alkaline phosphatase even though false positive tests are common. Use of paired admission and predischarge data reduces the false positive rate by approximately 50% thereby reducing the requirement for histological confirmation of the diagnosis of osteomalacia. Since the prevalence of osteomalacia is low in this type of hospital population, any measure which reduces the requirement for bone biopsy is of considerable practical value.

Bone samples were taken at post-mortem examination by Jamshidi needles from 88 elderly patients who were known to have normal bone biochemistry in life. The extent of osteoid in these samples is quantitatively described. In patients with normal creatinines the relative osteoid area ranges from 0 to 3.7% and trabecular osteoid surface percentage ranges from 0 to 23%, but higher values were seen in those with raised creatinines. Osteoid extent did not vary with age, sex or time of year. Descriptions of other series of control bone biopsies in the literature are reviewed and it is suggested that relative osteoid area greater than 3.5% or osteoid surfaces greater than 25% should be considered excess osteoid.

Four years experience in the use of a new orthogeriatric unit run jointly by the orthopaedic Trauma service and the Department of Health Care of the Elderly is presented. There were over 1000 admissions during this period. The Unit was opened in 1978 and was established to meet the increasing problems stemming from fractures of the proximal femur in elderly women. During the ten-year period from 1971 to 1981 the number of patients with fractures of the proximal femur admitted to the orthopaedic trauma unit in Nottingham has doubled--from 290 cases in 1971 to 612 cases in 1981. The effect of the orthogeriatric unit has been to reduce the average length of hospital stay for these patients from 66 days in 1977 before the unit opened, to 48 days in 1979 with a rate of discharge to home or to relatives of 69 per cent of patients: inpatient case fatality within the unit has been 5 per cent.