Abstract
Aim: Concerns have been expressed that DMARDS may interfere with bone healing. Previous studies give conflicting advise and no consensus exist in current practise especially with the newer DMARDS such as Leflunomide, Etanercept, and Infliximab. The aim of this study was to assess the in-vitro effect of DMARDS and cox-2 inhibitors on Osteoblast activity.
Method: Osteoblasts were cultured from femoral heads obtained from five young otherwise healthy patients undergoing total hip replacement The cells were cultured using techniques that have been previously described. A computer aided design of experiment was used as a model for setting up the experiment on samples obtained from the five patients. Normal therapeutic concentration of the various DMARDS was added alone and in combination to the media. The cell growth was estimated after two weeks using spectrophotometric technique using Roche Cell proliferation Kit. Multiple regression analysis was used to estimate the best predictor of the final result.
Results: The most significant factor (p< 0.001) in predicting the ultimate response was the patient themselves. Cox-2 inhibitor (Etoricoxib) was found to have the most consistent effect although always in combination with some other drug which varied amogst different patients. Etoricoxib in fact had a stimulatory effect (R=0.219) on the osteoblast growth.
Conclusion: Different patients respond differently to the drugs. None of the DMARDS tested inhibit osteoblast proliferation and differentiation in-vitro. If osteoblastic activity is considered to be the primary factor responsible for bone healing, then an inhibition should not result in patients who are on these drugs.
Correspondence should be addressed to the Honorary Secretary, BOFSS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
