S 03/10 CFP Hip Prothesis

"Bone Metabolic Response to CFP Hip Prothesis with and without Zoledronic Acid. A Clinical PET/CT and DXA Study."

Dr. Gösta Ullmark MD. PhD. Ortoped Kliniken, Gävle, Sweden
(Laufzeit: 05/10 - 07/18)

Abstract 1: Temporal changes in [18F]PET/CT and biomarkers in patients with unilateral osteoarthritis of the hip, OAH, operated with the uncemented CFP®-stem. Six months of Follow-up. A. Nyström1, D Kiritopoulos1, S Lazarinis1, G Ullmark2, J Sörensen3, J Milbrink1, N Hailer1, H Mallmin1. 1Ort. Klin. Akademiska sjukhuset, 2Ort Klin Gävle Lasaret, 3PetCentrum, Akademiska sjukhuset Introduction: Uncemented total hip arthroplasty (THA) is associated with periprosthetic loss of bone mineral density, BMD. Patients and Methods: We investigated the relation between periprosthetic Standardized Uptake Value, SUV(osteoblastic activity), by [18F]PET/CT, BMD, by DXA, and biochemical markers for bone metabolism, i.e. morning fasting blood samples for a bone formation marker, P1NP and a bone resorption marker, Crosslaps. Fifteen patients (age 60±4, 11 females), controls in a RCT, were operated with a CFP®-stem (hydroxiapatite coated titanium stem), Waldemar Link, and were followed for six months. Changes from baseline were analysed using Wilcoxon signed rank test. Statistical significant changes p<0.05 were considered relevant.
Results: SUV in “Gruen” 1-7 increased by 76% at 3 months and 54% at 6 months. Preoperatively P1NP was 46(±17), decreased direct postoperatively to 31(±14) and increased at 3 (80±38) and 6 months (56±24). S-βCrossLaps decreased direct postoperatively from 480(±209) ng/l to 383(±183)ng/l. At 3 and 6 months there was no change from baseline. BMD in Gruen zone 7 decreased by 16% at 6 months. Discussion: A previous study has shown that periprosthetic BMD for the CFP®-stem decreases already at 3 months. This study confirms this but also shows that bone formation measured as SUV and P1NP, increases during the first six months after THA. Conclusion: Bone formation increases during the first 6 months postop but there is a net loss of BMD in Gruen zone 7.

Abstract 2: Subgroup analysis of a Randomised Clinical Trial, RCT: Effects of Denosumab in patients with unilateral osteoarthritis of the hip, OAH, operated with an uncemented CFP®-stem. Six months of follow-up. A. Nyström1, D Kiritopoulos1, S Lazarinis1, G Ullmark2, J Sörensen3, J Milbrink1, N Hailer1, H Mallmin1. 1Ort. Klin. Akademiska sjukhuset, 2Ort Klin Gävle Lasaret, 3PetCentrum, Akademiska sjukhuset Introduction. Uncemented total hip arthroplasty (THA) is associated with loss of bone mineral density, BMD, at the proximal part of the femur after two years. Patients and Methods: We conducted an RCT to investigate whether the antiresorptive effect of Denosumab can prevent periprosthetic bone loss. Thirty one patients (age 59±5) patients were randomised to two subcutaneous injection with 1 ml Denosumab, or 1 ml NaCl starting within the first two days after surgery and after six months. The patients were investigated for Standardised Uptake Value, SUV(osteoblastic activity), by [18F]PET/CT, BMD by DXA, and biochemical markers for bone metabolism, i.e. morning fasting blood samples for a bone formation marker, P1NP, and a bone resorption marker, Crosslaps. Linear models were used to evaluate treatment differences with respect to, SUV, BMD, and biochemical markers of bone turnover. Results: The Denosumab group showed a 26% increase in SUV at six months, compared to 76% in the placebo group. (p=0.02). The Denosumab group showed a 12% reduction in P1NP level, compared to 23% increase in the placebo group. (p<0.05). The Denosumab group showed a 54% red