rhBMP-2 and Intramedullary Fixation in Congenital Pseudarthrosis of the Tibia.
BACKGROUND
In congenital pseudarthrosis of the tibia, use of intramedullary (IM) fixation and autogenous bone graft has long been the standard of care. This study was undertaken to determine whether the addition of rhBMP-2 to this treatment method further enhances healing potential.


METHODS
Twenty-one patients with congenital pseudarthrosis of the tibia were evaluated. Fifteen of these patients had neurofibromatosis type 1 (NF1). All had IM fixation and autogenous bone graft, followed by a BMP-soaked collagen sponge wrapped around both the fracture site and bone graft. A minimum 2 years' follow-up was required.


RESULTS
Follow-up averaged 7.2 years (range, 2.1 to 12.8 y). Sixteen of 21 tibias achieved bone union following the index surgery, at an average 6.6 months postoperatively. The 5 persistent nonunions occurred in NF1 patients. Further surgery was undertaken in these 5 NF1 patients, including the use of BMP. One of the 5 healed, 1 had persistent nonunion, and 3 eventually had amputation. Of the 16 patients who healed initially following the index surgery, 5 refractured (3 had NF1). Of these 5 patients, the IM fixation at the index surgery did not cross the ankle joint, and refracture occurred at the rod tip in 4. Three of these 5 patients healed following further surgery, 1 had persistent nonunion, and 1 had amputation. All of those with eventual amputation had NF1. No deleterious effects related to the use of BMP-2 were recognized in any patient.


CONCLUSIONS
The addition of rhBMP-2 appears to be helpful in shortening the time required to achieve fracture union in those who healed, but its use does not insure that healing will occur.


METHODS
Level IV-therapeutic, case series.
Texas Scottish Rite Hospital for Children, Dallas, TX.
B Stephens
BS
Richards
Walter Reed National Military Medical Center, Bethesda, MD.
Terrence D
TD
Anderson
D000293:Adolescent; D055396:Bone Morphogenetic Protein 2 / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D006801:Humans; D007223:Infant; D008297:Male; D009456:Neurofibromatosis 1 / Q000150:complications*; D011542:Pseudarthrosis / Q000150:complications / Q000151:congenital*; D011859:Radiography; D011994:Recombinant Proteins / Q000627:therapeutic use; D012189:Retrospective Studies; D013978:Tibial Fractures / Q000209:etiology / Q000601:surgery*; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*
D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2