Saturday, March 3, 2001
A long-term follow-up study, based on the experience with 55 patients who underwent proximal tibia endoprosthetic reconstruction, emphasizes reconstruction of the extensor mechanism.
Between 1980 and 1997, 55 patients underwent proximal tibia resection with endoprosthetic reconstruction. There were 34 males and 21 females whose age ranged from 8 to 56 years (median: 27 years). Diagnoses were: primary bone sarcomas--48; benign aggressive lesions--6; and failure of previous osteoarticular allograft reconstruction--1.
Intraarticular resection with en bloc removal of the tibial tuberosity was performed in all cases. Endoprosthetic reconstruction was performed with 39 modular, 16 custom-made prostheses. Reconstruction of the extensor mechanism included reattachement of the patellar tendon to the prosthesis with a Dacron tape and reinforcement with a gastrocnemius flap and bone grafting of the patellar tendon-prosthesis interface. Rehabilitation emphasized prolonged immobilization of knee joint in full extension.
All patients were followed for a minimum of two years (range 24-235 months, median: 75.5 months). Full extension to extension lag of 20 degrees was achieved in 44 patients (78 percent), extension lag of 20 degrees to 30 degrees was found in 10 patients (19 percent), and extension lag of 40 degrees was found in one patient (3 percent).
Eight patients required an additional procedure that involved reinforcement of the patellar tendon with either combined quadriceps tendon and Goretex graft construct (seven patients) or simple plication of the tendon (one patient). Seven of these patients gained an extension lag of less than 20 degrees. Overall, function was estimated to be good to excellent in 48 patients, fair in six, and poor in one patient.
The researchers said extension lag of up to 20 degrees is considered compatible with activities of daily living. "Emphasis on reattachment of the patellar tendon to the prosthesis and its reinforcement with a gastrocnemius flap and bone graft achieved that goal in the majority of the patients," the researchers said. "Secondary reinforcement of the patellar tendon is recommended for extension lag of more than 20 degrees."
The researchers are Jacob Bickels, MD, Sourasky Medical Center, Tel-Aviv, Israel: James C. Wittig, MD, Washington Hospital Center, Washington, D.C.; Yehuda Kollender, MD, Tel-Aviv Medical Center, Tel-Aviv, Israel; Robert S. Neff, MD, Washington, D.C.; Kristen L. Kellar-Graney, BA, Washington Cancer Institute, Washington, D.C.; Isaac Meller, MD, Sourasky Medical Center, Tel-Aviv, Israel; and Martin M. Malawer, MD, Washington Cancer Center, Washington, D.C.
|2001 Academy News March 3 Index B|
Last modified 20/February/2001 by IS