The Incidence of Osteopenia and Osteoporosis in Patients with Cementless Total Hip Arthroplasty

Abstract

PURPOSE OF THE STUDY The aim of the study was to evaluate the incidence of osteopenia and osteoporosis in the patients elected to cementless total hip replacement. MATERIAL AND METHODS The group evaluated comprised 100 patients with primary or secondary forms of coxarthrosis who underwent cementless total hip arthroplasty (THA). The results of densitometric examination of the lumbar spine and proximal femur were analysed. Based on the lowest T-score value, the patients were divided into three groups, i.e., first, normal bone density; second, osteopenia; third, osteoporosis. Clinical examination included patient medical history, Harris hip scores and visual analogue scale assessment for pain intensity; the Kellgren-Lawrence clasification was used to measure the grade of hip osteoarthritis; blood tests were made to assess the levels of total calcium, ionised calcium, phosphorus, vitamin D and the markers of bone resorption and formation. RESULTS Osteoporosis was found in 32 and osteopenia in 21 patients; 47 patients had normal bone density. Osteoporosis was detected in the lumbar spine of 21 patients, in the proximal femur of nine patients and at both sites in two patients. In 13 patients this diagnosis was made for the first time. The patients with osteoporosis had a significantly lower body mass index. There were no differences in the other characteristics, i.e., age, functional, radiological and laboratory findings, among the groups; all three showed the mean vitamin D concentration below the lowest level of its physiological range. Insufficient vitamin D levels were found in 54 women and 18 men. Of all patients, only 13 women and four men took vitamin D supplements. DISCUSSION Osteoarthritis and osteoporosis are the most frequent complex musculoskeletal diseases. Several studies have suggested that these disorders are mutually exclusive. This assumption has been based on the absence of radiographic evidence of osteoarthritis seen in many elderly patients with femoral neck fractures. Our relatively frequent findings of osteopenia and osteoporosis in this study show that patients with osteoarthritis may not be protected from the development of generalised osteoporosis. Our results are compared with the relevant literature data and potential effects of osteoporosis and vitamin D deficiency on total hip arthroplasty are discussed. CONCLUSIONS Hip osteoarthritis does not reduce the risk of generalised osteoporosis. We found a relative high incidence of osteopenia and osteoporosis as well as vitamin D deficiency in patient with advanced form of hip osteoarthritis.