ABSTRACT
BACKGROUND: Metacarpal index (MCI), measured from hand radiographs as the ratio between combined cortical thickness and bone diameter, has been suggested for assessment of bone mass and risk of osteoporotic fracture. We studied MCI for its ability to predict hip fractures. METHODS: Hand radiographs were taken and MCI determined in 3,561 subjects from a representative population sample of 8,000 Finns who were 30 years of age or over in 1978-80. Record linkage to the National Hospital Discharge Register identified 117 subjects who had been hospitalized for primary treatment of hip fracture by the end of 1994. RESULTS: High age, low body mass index, tall stature and smoking at baseline showed, independently of each other, significant associations with low MCI. Low MCI was a strong predictor of hip fracture. When adjusted for all potential confounding factors, the relative risk of hip fracture per decrement of MCI by one standard deviation (0.1) was 1.5 (95% CI 1.2-1.8). INTERPRETATION: Low MCI is associated with known risk factors of osteoporosis and predicts hip fracture. Since hand radiographs are easily available at low cost, measurements of MCI can be used as an alternative approach to find osteoporotic individuals with a high risk of hip fracture.
Subject(s)
Hand/diagnostic imaging , Hip Fractures/diagnosis , Metacarpal Bones/diagnostic imaging , Metacarpus/anatomy & histology , Osteoporosis/diagnosis , Absorptiometry, Photon , Adult , Aged , Bone Density , Female , Follow-Up Studies , Hip Fractures/diagnostic imaging , Hip Fractures/etiology , Humans , Male , Middle Aged , Osteoporosis/complications , Osteoporosis/diagnostic imaging , Osteoporosis, Postmenopausal/complications , Osteoporosis, Postmenopausal/diagnosis , Osteoporosis, Postmenopausal/diagnostic imaging , Predictive Value of Tests , Prospective Studies , Risk Factors , Socioeconomic Factors , Surveys and QuestionnairesABSTRACT
BACKGROUND: This study was designed to investigate the prevalence of osteoarthritis in the carpometacarpal joint of the thumb in adults thirty years of age or older in Finland. METHODS: Between 1978 and 1980, a representative population sample of 8000 Finns thirty years of age or older were invited to have a comprehensive health examination; 90% accepted. Hand radiographs were made of 3595 subjects. Since the examination, the subjects have been followed systematically to assess work disability and mortality by reviewing registers covering the whole population. RESULTS: The age-adjusted prevalence of thumb carpometacarpal osteoarthritis of Kellgren grade 2, 3, or 4 was 7% for men and 15% for women. After adjustment for age, sex, and other alleged risk factors, body mass index was found to be directly proportional to the prevalence of thumb carpometacarpal osteoarthritis in both sexes. The adjusted odds ratio was 1.29 (95% confidence interval, 1.15 to 1.43) per 5-kg/m(2) increment in body mass index. No significant association was found between the physical workload history and thumb carpometacarpal osteoarthritis. Restricted mobility of the thumb and local tenderness and swelling were frequently found in conjunction with radiographic evidence of thumb carpometacarpal osteoarthritis. Advanced (grade-3 or 4) thumb carpometacarpal osteoarthritis predicted the total mortality rate in men (adjusted relative risk, 1.32; 95% confidence interval, 1.03 to 1.69). Radiographic signs of thumb carpometacarpal osteoarthritis did not predict work disability. CONCLUSIONS: and CLINICAL RELEVANCE: Obesity is a strong determinant of thumb carpometacarpal osteoarthritis in both sexes. The effect of thumb carpometacarpal osteoarthritis on disability and mortality in the general population is modest. Because of the rarity of ensuing disability, carpometacarpal osteoarthritis of the thumb is likely to be underdiagnosed in clinical practice.
