Discussion:
Osteosarcoma is the most common primary malignant bone tumor, occurring mainly in children and adolescents, and the limbs are the main affected sites. (1) Osteosarcomas are most commonly located in the metaphysis of long bones, especially around the knee in the distal femur or proximal tibia, Osteosarcoma incidence is bimodal, peaking at 18 and 60 years of age, and is slightly more common in males.(3) Osteosarcoma was treated with amputations to control the gross disease with survival rates of 20%–30%, Later on it was clarified that the best management plan for osteosarcoma is the introduction of neoadjuvant systemic chemotherapy followed by a surgical procedure to remove the malignant regions and adjuvant chemotherapy that has improved the survival rate to 70%–80%, Nowadays, Limb-salvage surgery (LSS) with neoadjuvant chemotherapy is the preferred option for osteosarcoma management by most surgeons. (10)
LSS refers to the surgical procedure to restore bone and joint function after extensive resection of malignant bone tumors of the limbs, Limb-salvage treatment has become one of the standard treatment methods for patients with limb osteosarcoma, with 90% of patients undergoing LSS and a success rate of 60%–80%. (13, 14) We followed this plan in this case and the surgery was success.
Patients treated with limb salvage or amputation experience similar survival, local recurrence, and complications, but better function is achievable for patients treated with limb salvage versus amputation. Local recurrence and complications are more common in patients with limb salvage. (11) LSS results in higher 5-year survival rates and better survival, while not increasing the risk of local recurrence; this study provided more evidences to support limb salvage surgery as a considerable treatment of osteosarcoma patients.(12)
Lower limb reconstruction is more acceptable psychologically to patients with severe lower limb trauma compared with amputation, even though the physical outcome for both management pathways was more or less the same.(15) Our patient was very young because of that LSS was the plan choice for him; his psychological status was preserved and had a better function.
Joint-preserving reconstruction using frozen autografts yielded excellent function in patients with osteosarcoma. (16)In this study patients sent to neoadjuvant chemotherapy, applied the affected bone to liquid nitrogen and underwent joint-preserving reconstruction. The result: patient responded to chemotherapy and their surgeries were success, patients could bend their knee more than 90 degree and some of them achieved full range of movement. Our patient had the same plan and got the same result.
Treating osteosarcoma around the knee with limb-salvage surgery can preserve most of the knee’s functionality. (17) In this study all patients were followed for 6-144 months (mean of 56.8 months), the overall 5-year survival rate was 61.8%, lung metastasis developed in 31 patients. (17) In our case most of the knee function was preserved, follow up was 5 years; during follow up patient came with small lung nodule. The flap transposition of the medial head of the gastrocnemius muscle can reconstruct the soft tissue defect, decrease the local complication rate and improve the clinical outcome of the limb salvage for the proximal tibia malignant tumor.(18) The flap transposition of the medial head of the gastrocnemius muscle can reconstruct the soft tissue defect, decrease the local complication rate and improve the clinical outcomes of the limb-salvage for the proximal tibia osteosarcoma. (19)
Transposition of the gastrocnemius muscle after resection of proximal tibial tumors can improve the local blood supply, cover the deep structures and prevent from the failure of limb-salvage operation due to wound complications. (20) The unique vascularization of the gastrocnemius muscle (one pedicle to each head), the size of the muscle belly, the fact that it is situated in the dissection field and that its transfer does not affect the function of the spared limb too adversely, makes it particularly suitable for limb sparing procedures for sarcoma in the region of the knee and popliteal fossa, the medial head is the workhorse muscle flap for soft tissue coverage of knee endoprothesis and reconstruction of extensor mechanism, this decreases the rate of complications and improves the functional outcome, reconstruction of the soft issue defect improves wound healing, protects exposed deep structures and subsequently prevents wound problems, delays adjuvant therapy and secondary amputation. (21)