2001 CTOS Annual Meeting Posters— Surgery

DISTAL FEMUR RESECTION WITH ENDOPROSTHETIC RECONSTRUCTION: A LONG TERM FOLLOW-UP STUDY
Jacob Bickels¹,  James C Wittig²,  Yehuda Kollender¹,  Robert M Henshaw²,  Robert S Neff²,  Isaac Meller¹,  Martin M Malawer^2
1National Unit of Orthopedic Oncology Tel-Aviv Sourasky Medical Center,  ²Division of Orthopedic Oncology Washington Cancer Institute Washington Hospital Center

METHODS: There were 61 males and 49 females who ranged in age from 10 to 80 years. Nineteen patients were younger than 12 years of age. Diagnoses included 99 malignant tumors of bone, 9 benign-aggressive lesions, and 2 non-neoplastic conditions that had caused massive bone loss or articular surface destruction. Endoprosthetic reconstruction included 73 modular, 27 custom-made, and 10 expandable prostheses. Only eight patients had a constrained knee mechanism; the remaining patients underwent reconstruction with a rotating-hinge knee mechanism. All prostheses were fixed with bone cement. Soft-tissue reconstruction included 21 medial, 3 lateral, and one bilateral gastrocnemius flaps. All patients were followed for more than 2 years (range, 2-16.5 years; average, 5.2 years); Follow-up included physical and radiological evaluation and functional evaluation according to the American Musculoskeletal Tumor Society System.

RESULTS: Function was estimated to be good or excellent in 94 patients (85.4%), moderate in 9 patients (8.2%), and poor in 7 patients (6.4%). Patients who underwent reconstruction with a rotating-hinge knee mechanism were more likely to have a good-to-excellent functional outcome (91%) than those who underwent reconstruction with a constrained knee mechanism (50%). Complications included six deep wound infections (5.4%), which resulted in three amputations, two prosthetic revisions, and one wound debridement. There were six local recurrences, five of which were treated with wide local excision, and one necessitated amputation. Overall, there were 14 revision surgeries; these included replacement of failed polyethylene component in 6 patients and prosthetic revision in 8 patients (aseptic loosening – 5; deep infection – 2; and radiation bone necrosis –1). There were six local recurrences, five of which were treated with wide local excision, and one necessitated amputation. Prosthetic survival was 94% at 5 years and 91% at 10 years and overall limb salvage rate was, therefore, 96%.

CONCLUSION: Distal femur resection with endoprosthetic reconstruction is a safe and reliable procedure, which provides good local tumor control. The use of cemented endoprostheses, combined with a rotating-hinge knee mechanism provide immediate mechanical stability, allows early mobilization and good-to-excellent function in most patients. The use of endoprostheses is recommended by the authors for reconstruction of large segmental defects of the distal femur. Distal femur resection with endoprosthetic reconstruction is a safe and reliable procedure, which provides good local tumor control. The use of cemented endoprostheses, combined with a rotating-hinge knee mechanism provide immediate mechanical stability, allows early mobilization and good-to-excellent function in most patients. The use of endoprostheses is recommended by the authors for reconstruction of large segmental defects of the distal femur.