Assessing a 12-month course of oral alendronate for adults with avascular necrosis of the hip: MANTIS RCT with internal pilot.

ABSTRACT

WHAT WAS THE QUESTION?: The Managing Avascular Necrosis Treatments: an Interventional Study ( MANTIS ) trial was designed to compare ways of treating patients with avascular necrosis who are seeking to slow down the deterioration of their condition. Alendronate is a drug routinely available across the NHS in both tablet and injection form, and doctors and scientists believe that it might prevent ongoing hip deterioration and result in fewer patients requiring a total hip replacement. WHAT DID WE DO?: This trial attempted to compare alendronate taken as a tablet with an identical-looking tablet that did not contain any of the drug (a placebo) to find out if alendronate reduced the number of patients requiring a hip replacement and having pain (compared with patients who did not get alendronate). WHAT DID WE FIND?: Patients were willing to participate in the trial but we were able to recruit only a small number to the study. The main reason for this was difficulty in identifying potentially suitable patients and approaching them at the right point in their medical care. This was more challenging than anticipated, particularly because the NHS sites and professionals that patients with this condition seek out are extremely variable in the UK. It was also difficult to locate and identify patients with the condition at an early enough stage, and before they had already started taking the drug. WHAT DOES THIS MEAN?: More information on patients with this rare condition, such as NHS referral pathways, and an understanding of how the condition progresses may help to improve our understanding of this patient group. This information could also help us determine whether or not there is scope to carry out the study in a different way that might enable these patients to be more easily identified.