Long-term results of alloplasty and endoprosthetics of the knee joint with a tumor lesion of the distal end of the femur. Clinical observation (to the 100th anniversary of the birth of Professor A.S. Imamaliev)

BACKGROUND: Alloplasty of the articular ends of bones in cases of tumor lesion with canned grafts was actively used in 1960–1980. A study by A.S. Imamaliev on obtaining and preserving bone grafts and their application in clinical practice played a crucial role. A prospective direction for the development of this method was the use of a graft of the articular end of the bone combined with an endoprosthesis. With the development and improvement of joint replacement, modern designs of oncological endoprostheses have replaced the use of allografts of the articular ends of bones. Despite continuous improvements in the designs of oncological endoprostheses and surgical intervention techniques, the incidence of infectious complications, instability, and mechanical damage of the endoprosthesis in the postoperative period remains high.

AIM: to investigate the complex path of alloplasty of articular bones in a tumor lesion from replacement with a preserved transplant to the use of an oncological endoprosthesis and analyze the difficulties and complications encountered using a clinical observation lasting 45 years. Based on the study of medical histories and radiographs, the results of treatment of a patient with a giant cell tumor of the distal end of the femur were traced from 1979 to 2023.

CLINICAL CASE DESCRIPTION: The use of massive grafts of the articular ends of bones to replace bone defects in cases of tumor lesions restores the anatomical shape and normal interposition of the surrounding tissues. Fusion of the graft with the bone occurs 6–12 months postoperatively. However, achieving a strong connection of the graft with the bone, restoring stability in the joint, and early onset of movements and operated limb loading are challenging. Reconstruction of the graft reduces its mechanical strength and can cause a fracture of the graft, which requires its removal. The combined use of an allograft reinforced and interstitial endoprosthesis enabled operated limb loading and joint movement immediately after the operation. The function of the joint and ability to support the limb were restored; however, fractures in the legs of the endoprosthesis and their loosening in the bones were observed, which required several revision interventions.

CONCLUSION: The use of implants made of composite materials reinforced with modern designs of high-strength wear-resistant endoprostheses will improve the results of treatment of patients with defects in the articular ends of bones.