Background and aims: Loosening of a hip prosthesis after total arthroplasty is related to periprosthetic bone loss. Calcitonin has been used in the treatment of bone loss in osteoporosis and prevention of fractures. The main purposes of the study were firstly to evaluate the effect of calcitonin on periprosthetic bone after total hip arthroplasty, secondly investigate possible loosening of the prosthesis and thirdly examine further clinical outcome.
Patients and methods: 60 patients who underwent total hip arthroplasty using cemented Exeter prosthesis were randomized in the treatment group (salmon calcitonin 200 IU nasal spray daily + calcium 500 mg) and the placebo group (inactive nasal spray + calcium 500 mg) for six months. Bone mineral density (BMD) was measured from different locations at the time of discharge and after six and 12 months. Dynamic histomorphometry on bone biopsies taken from femoral collum was performed. Serum bone-specific alkaline phosphatase (BAP), serum osteocalcine (OC) and cross-linked N-telopeptides (NTX) were measured after one week, one month, three months and 12 months. Clinical manifestations and the incidence of fractures and loosening of the prosthesis were followed up to eight years.
Results: Statistically there was not significant difference in bone histomorphometry between the groups. In both groups there was a significant BMD decrease in periprosthetic bone. However, the difference between the groups was not statistically significant. In the biochemical analysis NTX increased more in the Miacalcic group than in the placebo group (p = 0.013). There were no significant differences between the groups in serum BAP or OC even though the changes within the groups were statistically significant. No loosening of the prosthesis was seen during the follow-up and there was no need for revision of any reason. Four fractures were recorded in three patients. One patient sustained a periprosthetic fracture. All the patients with fractures were allocated in the placebo group.
Conclusions: Nasal salmon calcitonin 200 IU on a daily basis does not promote any additional value on calcium substitution to prevent bone loss after hip replacement. The durability of the Exeter prosthesis was good.