Rodding in OI and Avery Boiko

Treatment with bisphosphonates allows clinicians to perform rodding surgery on younger children. Children taking bisphosphonates are more active and want to stand and walk sooner. Without bisphosphonates, the typical age for first rodding surgery was 3-4 years. With bisphosphonates, it can be as early as 18 months, or as soon as the child has begun trying to walk. Rodding appears to be justified if the femur is bowed 20% or more. Tibias could be braced or rodded at 20%. There is no method for evaluating the number of breaks required before rodding becomes necessary. The rod may not need to be removed if there are no problems. Growth rates with the rod and bisphosphonates are better than growth rates without.
The new Fassier-Duval rod was developed to protect joints and growth plates, reduce rod migration and offer less invasive surgery. It allows surgeons to avoid arthrotomy (opening the knee), and provides for quicker rehabilitation. Possible complications of all rods include joint intrusion, inability to telescope, epiphysiodesis (cessation of growth). Problems occurring with the new Fassier-Duval rods include some manufacturing defects that have been resolved and problems related to surgeon inexperience with the rod. It appears that 3/5s of the problems occurred during the learning curve. A 35% complication rate with the Fassier-Duval rod compares favorably with the 55% complication rate for the Bailey-Dubow rod. Fractures occur through the osteotomy site 20-25% of the time. It is not clear if a bone that is strengthened with rodding and/or bisphosphonate treatment will have enough muscle to protect and support it, especially when weight bearing activity increases, or starts soon after surgery.