Surgical Treatment of Bone Sarcoma

Abstract

Bone sarcomas are rare primary malignant mesenchymal bone tumors. The three main entities are osteosarcoma, chondrosarcoma, and Ewing sarcoma. While prognosis has improved for affected patients over the past decades, bone sarcomas are still critical conditions that require an interdisciplinary diagnostic and therapeutic approach. While radiotherapy plays a role especially in Ewing sarcoma and chemotherapy in Ewing sarcoma and osteosarcoma, surgery remains the main pillar of treatment in all three entities. After complete tumor resection, the created bone defects need to be reconstructed. Possible strategies are implantation of allografts or autografts including vascularized bone grafts (e.g., of the fibula). Around the knee joint, rotationplasty can be performed or, as an alternative, the implantation of (expandable) megaprostheses can be performed. Challenges still associated with the implantation of foreign materials are aseptic loosening and infection. Future improvements may come with advances in 3D printing of individualized resection blades/implants, thus also securing safe tumor resection margins while at the same time shortening the required surgical time. Faster osseointegration and lower infection rates may possibly be achieved through more elaborate implant surface structures.

Keywords: Ewing sarcoma; bone; chondrosarcoma; megaprosthesis; osteosarcoma; rotationplasty; tumor resection; tumor surgery.

Figure 1

Osteosarcoma of the distal femur treated with rotationplasty. A 5-year-old girl presenting with pain in the left thigh. (A) The plain a-p radiograph showed an osseous tumor (white arrow) of the distal left femur highly suggestive for osteosarcoma. Histopathologic analyses after open biopsy confirmed high-grade osteosarcoma. In MR imaging, it could be determined that it was located near vessels and nerves, respecting the epiphyseal plate. Due to the young age and the suitable location, we performed rotationplasty according to the technique of van Nes. Different techniques of rotationplasty have been proposed depending on the location of the tumor in the femur [47]. (B) Antero-posterior radiograph showing the osteosynthesis by means of an LCP plate in the subtrochanteric region. Clinical frontal (C) and lateral (D) image after wound healing.

Figure 2

Osteosarcoma treated with extraarticular knee resection and implantation of a megaprosthesis. A 20-year-old patient presenting with pain in the left knee and a progressive extension deficit. (A) Conventional radiographs showing osteolysis in the proximal tibia (red arrow). (B) MR imaging (T2-tirm coronal) was performed, suggesting that the corresponding medial femoral condyle might also be affected (gray arrow). Intraarticular contamination was, therefore, assumed. Biopsy sampling was performed, showing a G3 osteosarcoma (staging: T1, Nx, M0, IIA). The patient first received neoadjuvant therapy according to the EURAMOS protocol. Thereafter, we performed extraarticular tumor resection [53,54] and implanted a megaprosthesis (Implantcast, Femur RS/KRI and proximal Tibia MUTARS) (C). Although parts of the extensor mechanism can be preserved in this procedure, patients postoperatively do complain about problems with sufficient extension. Advanced soft-tissue management was required, with soft-tissue coverage over the proximal tibia being achieved by means of a medial gastrocnemius muscle flap and a medial soleus muscle flap. Histopathological examination showed complete resection of the tumor (R0) and a regression grade of 3 (according to Salzer-Kuntschik), for which reason adjuvant chemotherapy was continued according to the EURAMOS-1 protocol (“good response”).

Figure 3

Ewing sarcoma of the humerus treated with a vascularized fibula graft. A 6-year old boy presented in the ward with persisting pain for 2 months in the left upper arm accompanied by intermittent fever. The plain a-p radiograph shows the central osteolysis within the diaphysis (A). Open biopsy was performed, showing Ewing sarcoma. After neoadjuvant chemotherapy, we performed complete en bloc resection (R0). The defect was reconstructed using a vascularized fibula graft by our colleagues from the department of plastic surgery (B). Temporary stabilization was performed with an LC-DCP plating. Seven months postoperatively, the fibula appeared radiologically fully osseointegrated distally, but a non-union with fracture of the plate was present proximally between the second and third screw. The LC-DCP was removed, and a titan elastic nail inserted. Postoperative care was a total cast of the left arm. Three months postoperatively, autologous bone from the iliac crest was placed at the non-union site followed by again plating of the humerus (C). (D) One year thereafter, the osteosynthesis material could be completely removed. The patient could freely use his arm, with, in the plain a-p radiograph, only a slimmer silhouette of the diaphysis still reminding of the performed procedure. Even when using a vascularized bone, as in the present case, bone healing can be challenging due to the immediate continuation of chemotherapy after wound healing.

Figure 4

Chondrosarcoma treated with megaprosthesis. A 58-year-old patient presenting with a local prominence around the lateral knee. (A) Conventional radiographs showed an osteodestructive process in the region of the metaphysis affecting the bone cortex (red arrow). (B) A PDW-SPAIR MR coronal image illustrates the vast infiltration of the diaphysis distally (gray arrow). Open biopsy was performed, showing a highly differentiated chondrosarcoma (G1). Due to the destructive properties of this tumor, we performed complete resection (R0) and implanted a megaprosthesis matching the created defect (Implantcast, MUTARS proximal tibia) (C). A gastrocnemius and a soleus flap were performed to cover the foreign material at the site of the former tibia. The aponeurosis of the gastrocnemius was sutured on the patella tendon for additional stability of the extensor mechanism.

Figure 5

Chondrosarcoma of the pelvis treated with wide resection and reconstruction with allogenic and autologous bone graft. A 56-year-old patient presented in the ward with local low back pain. MR imaging showed a bone tumor in the postero-medial iliac crest (red arrow) with transgression of the sacroiliac joint (white arrow) (T2 tirm coronal (A) and axial (B)). Histopathological analyses after open biopsy showed a G1 chondrosarcoma with no other foci after staging. (C) En bloc resection was performed with a transiliacal osteotomy laterally and an osteotomy along the neuroforamina of the sacrum. Reconstruction was performed with a screw–rod system with three pedicle screws brought into the remaining iliac bone/acetabulum on the left and, on the right side, one S1 screw, one ilium screw, and one S2 ala-ilium screw. Allogenic bone was brought into the site of resection, augmented by an autologous rib. After 3 months of partial-weight bearing, the patient was allowed full-weight bearing. One year postoperatively, the patient had to be revised with a broken rod and incomplete osseointegration of the graft material. (D) Screw augmentation plus additional rod implantation were performed, accompanied by new autologous cancellous bone grafting. As an alternative procedure to the BMP-9 rich autologous rib, a vascularized fibula graft or the Capanna technique might have been used in this patient.