BACKGROUND:The greatest risk of osteoporosis in total knee arthroplastyisperioperative and long-term periprosthetic fractures. However, limited by the traditional concept of osteoarthritis patientswhousualy not associated with osteoporosis, domestic clinical trials have not given enough attention to the osteoporosis before total knee arthroplasty.
OBJECTIVE:To analyze the osteoporosis and its relative factors in osteoarthritis patients before total knee arthroplasty.
METHODS:Data of 81 cases (81 knees) of knee osteoarthritiswhounderwenttotal knee arthroplasty in the Department of Joint Surgery of Tianjin People’s Hospital from January 2012 to November 2014 were retrospectively analyzed. They received lumbar spine and hip bone mineral density examination before surgery. The correlation of bone mineral density with age, body mass index, knee motion range,and knee deformity was analyzed before surgery. The independent risk factors for osteoporosis before replacement were analyzed.
RESULTS AND CONCLUSION:(1) Of 81 patients, there were normal bone mineral density in 25 cases (31%), osteopenia in 35 cases (43%),andosteoporosis in 21 cases (26%). Al 10 males had no osteoporosis and 21 in 71 female cases suffered osteoporosis (30%). Theincidence of osteoporosis in females was significantly higher than in male patients (P=0.046). (2) There was a linear correlation of bone mineral density with age and body mass index (correlation coefficientr=-0.230, 0.225). (3) The age of≥65 years and body mass index≥25 kg/m2were independent risk factors of osteoporosis before replacement (P< 0.05). (4) Patients with knee osteoarthritis had higher incidence of osteopenia and osteoporosis before total knee arthroplasty. The degree of osteoporosis was negatively correlated with age, but positively correlated with body mass index. The age of≥65 years and body mass index < 25 kg/m2were independent risk factors for preoperative osteoporosis. Thus, bone mineral density examination is essential for those patients before total knee arthroplasty.