Paley Cross-Union Protocol for Treatment of Congenital Pseudarthrosis of the Tibia

Abstract

Success in treatment of congenital pseudarthrosis of the tibia (CPT) is defined as obtaining union without refracture. The success rate of most techniques (rodding, Ilizarov, rodding with Ilizarov, free vascularized fibula, etc.) is on average 50%. Recently a new technique has emerged that improves this success rate to as high as 100% in some reports. This new method involves creating a cross-union between the tibia and fibula. The Paley cross-union protocol starts with preoperative zoledronic acid infusion to protect the tibia, fibula and autogenous bone graft from resorption by the hyperosteoclastic cells in CPT. This is combined by radical circumferential hamartoma resection from tibia and fibula. The bones are fixed internally with telescopic rod and locking plate for the tibia and rodding with a wire for the fibula. Decancellousization, a new method of autogenous bone graft procurement from the ilium makes it possible to harvest enough graft even from the ilium of a 12-month-old child, to fill the interosseous space between the tibia and fibula. Insertion of BMP2 between the graft and the anterior and posterior muscles helps induce osteogenesis by cell recruitment from the muscles and from the bone graft. The cross-union is already bridged by 6 weeks in most cases and the CPT is healed by 12 weeks. The results are independent of association with NF1 or fibrous dysplasia, failed prior surgery or age under 3 years. This procedure has many steps and requires meticulous preparation and fixation of the tibia and fibula as well as great skill to harvest and adequate amount of bone graft in a small child. The author's technique has been reproduced by others with equal success.