Giant cell tumour (Osteoclastoma) is a benign, locally destructive tumour with low metastatic potential, but it has a tendency to recur after treatment. The primary areas of involvement are the ends of long bones, commonly the distal femur and proximal tibia. The most preferred treatment modality of the giant cell tumour is surgery.

Case report: A 52-year-old male presented with pain and slight swelling localized over the proximal left tibia and limited range of motion in the left knee. After histological confirmation of the diagnosis with open biopsy, en bloc resection of the lesion was made with a reconstruction of a knee joint with semi-constrained knee endoprosthesis and trabecular metal.

Conclusion: Selecting the appropriate treatment method is very important for the recovery of the function of the affected joint and for the whole extremity, as well. There is an advantage of en bloc resection and reconstruction with semi-constrained knee endoprosthesis in combination with trabecular metal in cases with extensive destruction of bone structure, recurrence, pathological fracture or difficulty in reconstruction after intralesional curettage. Advantages in functional aspect of this treatment modality are retaining the stability of the knee joint, substituting the bone defect and fast recovery of the function of the affected joint and limb.