Congenital Pseudarthrosis of the Tibia Dr. Dror Paley’s Treatment Protocol
14 years ago I developed a new method to treat congenital pseudarthrosis of the tibia. The results of this new method (in my hands) are: union in 100% of cases, refracture in less than 20% of cases, equal leg length in all, no deformity in all.
The method consists of all of the following once CPT occurs: 1. Open removal of the periosteum surrounding the bone of the CPT (this tissue is actually the pathologic tissue
2. Fitting the bone ends of the tibia one inside the other to thicken the bone healing area
3. Fixing the tbia and fibula with rods. The tibia is fixed with a special growing rod called the Fassier- Duval nail (I modified this nail for use in CPT, the original F-D nail was developed for osteogenesis imperfecta another disease and the lower end of the nail was not appropriate for CPT). The F-D nail is a telescopic nail fixed at each end to the epiphysis of each bone end. It expands with growth and does not restrict growth.
4. Obtaining a cancellous bone graft from the pelvis (most surgeons think it is not possible to get much bone from the pelvis in such a young child; I have developed a method to get the bone that is just above the hip joint without affecting the hip at all; this gives us plenty of bone graft)
5. Obtaining a periosteal graft from the underside of the iliacus muscle (this muscle is normally exposed when taking the bone graft (no additional incision is needed to get the periosteal graft)
6. The periosteal graft is meshed and then wrapped around the CPT site to replace the removed pathologic periosteum.
7. The bone graft is then placed circumferentially around the bone but especially between the tibia and the fibula to get the two bones to join together(getting them to heal together prevents refracture by creating a very wide bone healing area.)
8. Bone Morphogenic Protein (BMP) called INFUSE (manufactured by Medtronics in the USA) is placed around the bone graft and CPT site (CPT has reduced BMP response level which is important to bone healing and therefore adding BMP overcomes this deficit. (note this is an off label use of INFUSE)
9. Finally we add an external fixator to hold the bone together until it is healed ( we usually use an Ilizarov external fixator. An alternative to this that works just as well is to insert a subcutaneous locking plate. This acts as an internal external fixator. It offers the advantage that there are no pin infection and that it does not need to be removed early. If we use the Ilizarov it is used only as a holding device except in kids who have a leg length difference in which case we need to lengthen the leg at the same time. The Ilizarov is usually removed after 3 months. If we use the locking plate it can stay in for a year or more.
10. Two weeks after surgery we do a Zolidronic Acid infusion. Zolidronic acid (also called zolidronate or Zometa) is a 3rd generation biphosphonate. We use it in low dose and have never had a complication from it. In CPT the cells called osteoclasts whose job is to remove bone are overactive. ZA prevents this from happening by locking in all the calcium in the bone so it cannot be removed. This alters the balance between bone removal and bone formation in favor of bone formation which is being promoted by the BMP. The net result is healing of the bone with a lot of new bone formation.
While this protocol seems complicated it is designed to address the biomechanics and the pathologic biology of CPT.
No one has ever achieved as high a success rate of treatment of CPT. Success in CPT is dependant on understanding the pathoanatomy, pathobiology and pathomechanics as well as having extensive experience in the treatment of the condition. To my knowledge I have the largest personal experience in the treatment of this condition as well as the highest success rate.
Dror Paley, MD, FRCSC
ORTHOPEDIC EDUCATIONAL SITE BY THE MOST EXPERIENCED LIMB LENGTHENING SURGEON IN THE WORLD