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)