Investigators of this study found 65% of skeletally immature patients who were implanted with an expandable endoprosthesis after distal femoral resection had less tibial growth in the operative vs. contralateral limb and of these patients, 43% had progressive shortening.
“The tibial growth plate may not resume normal growth after implantation of a distal femoral prosthesis,” the authors wrote. “Physeal bar resection, prosthesis revision and contralateral tibial epiphysiodesis may be needed to address tibial growth abnormalities.”
The study included 23 skeletally immature patients who had a distal femoral primary sarcoma and underwent wide excision of the distal part of the femur and reconstruction with an expandable prosthesis between 1994 and 2012. Patients had a mean age of 9.9 years at the time of surgery, and the minimum follow-up was 12 months.
Results showed 15 patients experienced tibial length shortening compared with the nonoperated limb. The mean tibial length reduction was 9.1 mm for all 23 patients in the study. Investigators noted the discrepancy worsened during growth in 10 patients, with a mean tibial length reduction of 17 mm. This was a 4-mm reduction per growth year. In five patients, investigators found this discrepancy stabilized after surgery.
At the last follow-up, five patients had a tibial length discrepancy of about 20 mm and seven patients did not develop a tibial length discrepancy. Of the 23 patients in the study, 13 underwent contralateral tibial epiphysiodesis. Due to angular deformity at the proximal part of the tibia, three patients underwent reconstructive surgery. ‒ by Monica Jaramillo
Disclosure: The study was supported by the NIH/National Cancer Institute under award number P30CA016672.