Background: Parosteal osteosarcoma is a
low-grade malignant bone tumor that arises from the surface of the metaphysis
of long bones. Parosteal osteosarcoma is usually well differentiated
and displays a low propensity to metastasize. Wide resection of
a parosteal osteosarcoma has been shown to provide a relatively
risk-free method of preventing local recurrence. We propose a new
method of resection of parosteal osteosarcomas located in the popliteal paraosseous
space of the distal part of the femur. This method involves resection
of the mass through separate medial and lateral incisions, which
allows for wide margins yet limits the amount of dissection of the
soft tissues and the neurovascular bundle.
Methods: Six patients with parosteal osteosarcoma
located on the posterior aspect of the distal part of the femur
underwent resection of the lesion and reconstruction with a posterior
hemicortical allograft through dual medial and lateral incisions.
The patients were evaluated with regard to pain, postoperative function,
union of the allograft (osteosynthesis), and the prevalence of local recurrence.
Results: The average time until the last follow-up
assessment was 4.3 years. No metastases developed, and there were
no local recurrences. All patients were free of disease at the last
follow-up evaluation. Postoperatively, the average range of motion
of the knee was 0 to 122 degrees. Five of the six patients were
free of pain at the time of the latest follow-up. Five of the six
patients returned to their preoperative active functional status.
Conclusions: We recommend resection of a parosteal
osteosarcoma located on the posterior surface of the femur through
separate medial and lateral incisions. This approach provides minimal
dissection of the neurovascular bundle but ample exposure for reconstruction
with a hemicortical allograft.