Prevention of Inflammation in Perthes Disease Using Steroid Injections

All study patients will continue to get the routine orthopaedic treatment for Perthes Disease that is currently offered by their orthopaedic surgeon. The standard of care for Perthes disease varies widely. Going to the operating room to remove fluid (synovial) from the affected hip and placing a dye in the joint is one of the most common treatments for Perthes that assist the surgeon to better understand the hip and decide on future treatment. In addition to the above, patients in the study will be randomised into one of two (2) groups: Group 1 Will go to the theatre and undergo fluid aspirate of the hip (have fluid removed from the hip through a needle), arthrogram (dye in the hip joint), as well as an intra-articular injection of Triamcinolone Hexacetanide at 1mg/kg/joint which is a long acting steroid, mixed with 1% Ropivacaine (anesthetic). They will then have broomstick casting applied to both legs to keep the legs abducted (i.e. spread). At the time of the anaesthetic, they will also have a blood test done (5ml), through the same needle used to insert a cannula for the surgery. The operative procedure consists of performing, with the patient under general anaesthesia, a hip joint aspirate of synovial fluid (fluid removed from the hip) with a needle syringe. Once the aspirate is taken, a dye is injected into the joint and appropriate position is confirmed by fluoroscopy. The active or placebo syringe is then attached to the needle and the fluid is injected. The needle is then removed and the hip examined fluoroscopically in differing positions (Anterior-posterior (AP), abduction AP and frog lateral). A broom stick cast is then applied to maintain an abducted position post-operatively for 2 weeks. During the procedure, whilst the patient is asleep, a blood test will be drawn and sent for analysis for markers of inflammation that appear in the serum. Patients (regardless of randomised group) who fail to show significant improvement in their range of movement (Abduction more than 10 degrees AND Abduction < 20 degrees in extension) at Week 12 will have re-surgery and treated with an intra-articular injection of Triamcinolone Hexacetanide at 1mg/kg/joint which is a long acting steroid, mixed with 1% Ropivacaine along with a second Arthrogram.