Peter G. Passias, MD, 4th year resident, Tufts Affiliated Hospitals Orthopedic Surgery Residency Program, Medford, MA, USA.
James V. Bono, MD, Clinical Professor of Orthopedics, Tufts University School of Medicine; Director of Education, New England Baptist Hospital, Medford, MA, USA.

Total hip arthroplasty (THA) is one of the most commonly performed and successful operations in orthopedic surgery in terms of clinical outcome, implant survivorship, and cost-effectiveness. The average age for a patient undergoing a THA is 66 years. As life expectancy continues to increase in developed nations and the percentage of the population that is older than 65 years rises, THA surgery will be more frequently performed. This change in demographics is clinically relevant as the indications, risks involved, and outcomes are not identical to those of younger THA candidates. Osteoarthritis is by far the most common diagnosis among patients undergoing primary elective THA. Other common diagnoses include rheumatoid arthritis, other types of inflammatory arthritis, post-traumatic arthritis, and osteonecrosis of the femoral head. Patients that are candidates for THA have radiographic evidence of hip joint degeneration together with the clinical symptoms of disabling pain and functional limitation despite adequate nonsurgical management. The following article attempts to summarize some of the key issues regarding THA in an older population.
Key words: total hip arthroplasty, osteoarthritis, avascular necrosis, hip fracture, older population.

Barbara Liu, MD, FRCPC, Sunnybrook &Women's College Health Sciences Centre and the Kunin-Lunenfeld Applied Research Unit, Baycrest Centre, Toronto, ON.

Falls are a common problem among older patients. Medications in general, and psychotropic drugs in particular, have been shown to increase the risk of falls. The possible mechanisms whereby psychotropic drugs increase this risk include sedation, orthostatic hypotension, arrhythmias, confusion due to anticholinergic effects, and dopaminergic effects on balance and motor control. Several epidemiological studies have identified antidepressant use--both tricyclic and selective serotonin re-uptake inhibitors--as a risk factor for falls. When treating a patient with an antidepressant, efforts should be made to reduce other modifiable risk factors for falls by optimizing intrinsic and extrinsic risk factors for falls.
Key words: falls, antidepressant, hip fracture, tricyclic antidepressant, selective serotonin re-uptake inhibitor.

Use of oral contraceptives may lower the risk of hip fracture later in reproductive life, according to a report in the May 1st issue of the Lancet. Previous studies have shown a protective effect of postmenopausal oestrogen therapy on the risk of having a fracture. However, whether or not oral contraceptives, which also contain the hormone oestrogen, can confer a similar risk is not clear.

Dr Karl Michaëlsson and colleagues, from Sweden and the USA, collected data on all cases of hip fracture that occurred between October 1993, and February 1995, among women in Sweden. Questionnaires were then posted to these women who had had a hip fracture (the cases), and to a group of women who had not had a hip fracture (the control group) to ascertain details about the women's previous use of oral contraceptives.

Of the 1327 cases, 130 (11.6%) had used oral contraceptives. Of the 3312 controls, 562 (19.1%) reported previous use of oral contraceptives. The use of oral contraceptives was associated with a 25% reduction in risk of having a hip fracture later in life. Women who had previously taken an oral contraceptive containing a high dose of oestrogen had a 44% reduced risk of hip fracture.

Oestrogen in the oral contraceptive pill acts on bone, via a mechanism that is as yet unclear, making bones denser and stronger. After a woman has gone through menopause, her bone mass decreases naturally. The researchers postulatee that by increasing the bone mass before menopause, the mass will decrease by less overall, and state that oral contraceptive users appear to reach the menopause with a bone density 2 to 3% higher than that of non-users.

*Provided by The Lancet.

Contact: Dr Karl Michaëlsson, University Hospital, S 75185 Uppsala, Sweden
tel +46 18 663000; fax +46 18 509427; e-mail: Karl.Michaelsson@ortopedi.uu.se