Background: The knee is one of the most common places to develop a primary sarcoma. Malignant bone tumors are rare conditions that may be encountered by non-oncologic surgeons only a few times in their careers, but a delay in diagnosis or a misinterpretation of data can have limb and life-threatening consequences.
Methods: A retrospective analysis was conducted on 4 cases of knee joint problems. Patients admitted to the hospital between June 2016 to March 2019. We identified 2 males and 2 females with knee joint malignancy, aged 38 ~76 years. The diagnosis was confirmed by histopathology. All 4 patients underwent total knee joint tumor resection with prosthesis replacement.
Results: The interventions were successfully completed without vascular and nerve injury, but in 1 case, the wound healing was delayed. Knee function was recovered satisfactorily after 24-37 months of follow-up. At the last follow-up, the knee flexion angle range for the 4 patients was 95°, 100°, 100°, and 110°, respectively, and the delay of knee extension was 5°, 10°, 10° and 5°, respectively; tissue tumor association scores were 53%, 77%, 80%, and 83%. Quadriceps muscle strength was grade 4 in two cases and grade 5 in the other two cases. No tumor recurrence or metastasis was detected, and no death occurred.
Conclusion: We identified 4 cases of malignant tumor involving the knee in which total and partial excision and reconstruction were performed.