Open Synovectomy and Open Reduction with Internal Fixation of Right Distal Femur Fracture in a Pediatric High Titer Factor VIII Inhibitor Patient under Cover of rFVIIa.

Background: The development of inhibitors in patients with hemophilia constitutes a major challenge in the management of bleeding episodes. In general, it interferes with the proper treatment and eventually results in irreversible damage to joints and osteoarthritis. Joint bleeds are the most common manifestations of severe hemophilia. Recurrent bleeds within a target joint affect the range of motion, muscle strength, and appearance. In pediatric patients the knee and ankle joints are especially susceptible to chronic synovitis. The inability to utilize prophylaxis and the use of factor concentrates can result in incomplete correction of the hemostatic defect and can result in joint damage. Frequently, synovectomies are used as a last resort to secure hemostasis and control pain. This report describes possibly the first combination open right knee synovectomy and patella realignment/open reduction and internal fixation of the right distal femur procedure performed in a pediatric severe hemophilia A patient with high responding inhibitors.

Patient and Methods: The patient is an 11-year-old male with severe hemophilia A and a high responding factor VIII inhibitor with a history of hemophilic arthropathy. He is known to have chronic synovitis, effusion of the right knee, and chronic subluxation of the right patella. Prior to admission the patient fell and fractured his right distal femur. It was decided to proceed with open reduction and internal fixation of right distal femur fracture as well as subtotal synovectomy right knee, right lateral retinacular release, and right vastus medialis obliquus plication. Recombinant FVIIa (rFVIIa) was chosen to manage bleeding during the surgical procedure. The patient received 90 mcg/kg rFVIIa at 2 hour intervals for 24 hours pre-operatively, just prior to surgical intervention, and 15 minutes before tourniquet release.

Results: Prophylaxis with rFVIIa provided successful hemostasis and the surgery was completed without event. The dose of rFVIIa was continued at 2 hour intervals for 24 hours, then every 4 hours for 48 hours, and then every 6 hours. On post-operative Day 5, the patient experienced severe pain and edema of the extremity. A computed tomography (CT) scan of the right knee confirmed the presence of a large hematoma, and the dosage interval of rFVIIa was increased to every 2 hours. On post-operative Day 8, bleeding was observed at the site of incision. The patient’s hemoglobin/hematocrit levels dropped from 8.6%/25.3 gm/dL to 6.7%/19.9 gm/dL, requiring blood transfusion. On post-operative Day 10, 50 units/kg activated prothrombin complex concentrate (APCC) was administered every 8 hrs. On post-operative Day 16, the patient was discharged and was instructed to maintain activated prothrombin complex concentrate (APCC) dosing until his next hemophilia treatment center (HTC) visit on post-op Day 21.

Conclusions: Recombinant FVIIa provided successful coverage for the surgery, but the due to the extremely invasive nature of the surgical procedure, additional hemostatic agents were required.