One of the most challenging problems of limb salvage is a large tumor involving the knee joint. Since 1970,79 patients, ranging in age from 14 to 74 years (mean, 27 years), have had reconstruction of the knee after en bloc resection of a primary bone tumor. Sixty-one patients had lesions involving the distal femur, with a mean resection length of 13.5 cm, and 18 patients had lesions involving the proximal tibia, with a mean resection length of 10.5 cm. Thirty-nine patients had malignant lesions, of which osteosarcomas predominated, and 40 patients had benign tumors, of which giant cell tumors were the most prevalent. Reconstruction was done with a custom total knee arthroplasty in 41 patients, a resection arthrodesis in 27, and an allograft in 11. The functional results were graded according to the rating system devised by the Musculoskeletal Tumor Society. Of the patients with resection arthroplasty, 70% had a good or excellent rating, although ten required revision. Of the patients with resection arthrodesis, 74% had a good or excellent rating, as did 55% of the patients with osteochondral allografts. When a limb salvage procedure is done, careful consideration must be given to the type of procedure chosen to reconstruct the knee. This decision is based on a number of factors related to the tumor and the patient. Although these various procedures promise functional restoration, the reconstructive procedure should be individualized and designed to meet the needs of the patient.
* Consultant, Department of Orthopedics, Mayo Clinic and Mayo Foundation; Professor of Orthopedics, Mayo Medical School, Rochester, Minnesota.
** Senior Resident in Orthopedics, Mayo Graduate School of Medicine, Rochester, Minnesota.
† Consultant, Section of Biomechanical Research, Mayo Clinic and Mayo Foundation; Professor of Bioengineering, Mayo Medical School, Rochester, MN.