Expandable endoprosthesis reconstruction in skeletally immature patients with tumors

Between September 1984 and January 1996, 32 expandable endoprostheses were used for limb reconstruction after resection of malignant bone tumors in pa tients who were skeletally immature. The 20 boys and 12 girls ranged in age from 3 to 15 years (mean, 9.7 years). One patient had a Stage IIA tumor, 2 2 patients had Stage IIB tumors, and seven patients had Stage III tumors ac cording to the classification of the Musculoskeletal Tumor Society. There a lso were two patients with parosteal osteosarcomas. The histologic diagnosi s was osteosarcoma in 23 patients and Ewing's sarcoma in nine. All patients except the patients with parosteal osteosarcoma received standard neoadjuv ant therapy. Twenty-two Lewis Expandable Adjustable Prostheses, four modula r Wright Medical prostheses, four modular Howmedica prostheses, and two Tec hmedica expandable prostheses were used. Thirteen patients died, two have n o evidence of disease, and 17 are continuously disease free. Sixteen of 32 patients (50%) have not had an expansion procedure because of early death i n 10 and early amputation in three. Three patients are waiting to undergo a n expansion procedure. Sixteen of the 32 patients (50%) have undergone 32 e xpansion procedures, to a maximum of 9 cm, without any infection. To mainta in range of motion before the expansion procedure, a complete resection of the pseudocapsule was done routinely. Fourteen of the 32 patients did not h ave complications. Eighteen of the 32 patients had 27 complications. All Le wis Expandable Adjustable Prosthesis endoprostheses and the two nonmodular Techmedica prostheses were associated with a large amount of titanium debri s. The children's functional results were similar to the results reported f or adults with an average Musculoskeletal Tumor Society rating of good to e xcellent at the knee, fair to good at the hip, and fair about the shoulder. Rehabilitation of the knee in very young patients (5-8 years) remains prob lematic and careful selection of patient and family is necessary. The Lewis Expandable Adjustable Prosthesis probably should be reserved for very youn g patients (5-8 years) and modular systems should be used for large preadol escent and adolescent children.