Proximal Tibia Resection with Endoprosthetic Reconstruction in a 17-year-old Patient. Case Report

Abstract

Resection is a limb-sparing option for low-grade bony sarcomas and most high- grade (stage II A or II B ) sarcomas arising from the proximal tibia. In the past, several surgical and technical problems made it impossible to perform limb-sparing surgery for tumors at this site. These problems included anatomic constrains, difficult surgical approach, inadequate soft tissue coverage, vascular complications, and the need to reconstruct the patellar/extensor mechanism. Being aware of these challenges, most surgeons recommended above-knee amputations for these lesions.

The limb-sparing technique illustrated by this case allows a safe approach to the dissection of the popliteal vessels and to resection and replacement of the proximal one-third to two-thirds of the tibia. Preoperative evaluation of the tumor extent requires a detailed understanding of the anatomy and careful evaluation by computerized tomography (CT), magnetic resonance imaging (MRI), bone scintigraphy, and biplane angiography. The major contraindications to limb-sparing are a pathological fracture, neurovascular involvement, or contamination from a poorly positioned biopsy. One- half to two-thirds of the tibia was removed, along with a portion of all muscle inserting on the tibia and the entire popliteus muscle, in combination with an extra-articular resection of the proximal tibiofibular joint. The peroneal nerve was preserved. The surgical options for reconstruction are primary arthrodesis, prosthetic replacement, or allograft replacement. We preferred a prosthetic replacement; allograft replacement entails a high rate of infection, fracture, and local tumor recurrence. One key to the success of this procedure is the use of gastrocnemius muscle transfer to obtain reliable soft-tissue coverage that helps prevent skin flaps necrosis and secondary infections, and provides for reliable extensor mechanism reconstruction. Most patients with low- grade sarcomas and approximately half of those with high grade sarcomas can be treated by limb-sparing resection.