Carbon Fiber Implants in Orthopaedic Oncology

Abstract

Carbon fiber offers numerous material benefits including reduced wear, high strength-to-weight ratio, a similar elastic modulus to that of bone, and high biocompatibility. Carbon fiber implants are increasingly used in multiple arenas within orthopaedic surgery, including spine, trauma, arthroplasty, and oncology. In the orthopaedic oncologic population, the radiolucency of carbon fiber facilitates post-operative imaging for tumor surveillance or recurrence, the monitoring of bony healing and union, and radiation mapping and delivery.

Keywords: carbon fiber; orthopaedic oncology; pathologic fracture; prophylactic fixation; radiation therapy.

Figure 1

(A) Radiation therapy plan for a patient with impending pathologic fracture of the femur status post-intramedullary fixation with carbon fiber nail. Note is made of the minimal artifact from the intramedullary nail and relatively small amount of artifact from the metallic interlock screws. (B) Radiation therapy plan for a patient with impending pathologic fracture of the humerus status post-intramedullary fixation with titanium nail. Note the increased artifact caused by the intramedullary nail and interlock screws leading to increased target volume.

Figure 2

(A) Pre-operative T1 post-contrast, fat-saturation coronal; T2 fat-suppression sagittal; and T1 post-contrast, fat-saturation axial magnetic resonance images of a right tibia demonstrating a myxoid liposarcoma. (B) Post-operative radiographs demonstrating interval placement of an intramedullary carbon fiber nail. Note is made of a cortical defect in the tibia to allow for adequate resection margins; as such, a carbon fiber was placed for fracture prophylaxis. (C) The 9-month post-operative T1 post-contrast, fat-saturation coronal; T2 fat-suppression sagittal; and T1 post-contrast, fat-saturation axial magnetic resonance images demonstrating interval resection of the myxoid liposarcoma. Reduced artifact from carbon fiber nail facilitated visualization of the resection bed for monitoring of local recurrence. (D) The 20-month post-operative radiographs of the right tibia with intramedullary carbon fiber nail in place and healed cortical defect from prior resection margin.

Figure 2

(A) Pre-operative T1 post-contrast, fat-saturation coronal; T2 fat-suppression sagittal; and T1 post-contrast, fat-saturation axial magnetic resonance images of a right tibia demonstrating a myxoid liposarcoma. (B) Post-operative radiographs demonstrating interval placement of an intramedullary carbon fiber nail. Note is made of a cortical defect in the tibia to allow for adequate resection margins; as such, a carbon fiber was placed for fracture prophylaxis. (C) The 9-month post-operative T1 post-contrast, fat-saturation coronal; T2 fat-suppression sagittal; and T1 post-contrast, fat-saturation axial magnetic resonance images demonstrating interval resection of the myxoid liposarcoma. Reduced artifact from carbon fiber nail facilitated visualization of the resection bed for monitoring of local recurrence. (D) The 20-month post-operative radiographs of the right tibia with intramedullary carbon fiber nail in place and healed cortical defect from prior resection margin.

Figure 3

(A) Pre-operative anteroposterior (AP) and lateral radiographs of the distal femur and T1-post-contrast fat-saturation coronal magnetic resonance (MR) image of the knee, demonstrating a grade 2 chondrosarcoma of the medial femoral condyle. (B) The 12-month post-operative AP and lateral radiographs and proton density coronal MR image of the knee, demonstrating interval hemicondylar resection and osteoarticular allograft reconstruction with a carbon fiber plate and supplemental screw fixation. Minimal susceptibility artifact from the plate is noted with comparatively higher artifact from the metallic screws.

Figure 4

(A) Pre-operative anteroposterior (AP) and lateral radiographs of the right distal femur, demonstrating a lesion in the distal metadiaphysis. (B) Pre-operative post-contrast, T1 fat-suppressed coronal, sagittal, and axial magnetic resonance (MR) images of the distal femur further characterizing the high-grade dedifferentiated chondrosarcoma. Note is made of the cortical breach and extramedullary soft-tissue component. (C) Immediate post-operative AP and lateral radiographs of the right femur, demstatus post intercalary resection with allograft reconstruction utilizing a carbon fiber cephalomedullary nail and carbon fiber plate. (D) 15-month post-operative AP and lateral radiographs of the right femur, demonstrating allograft non-union and hardware loosening. (E) The 6-week post-operative AP and lateral radiographs of the right femur status-post removal of the carbon fiber plate and non-union revision open reduction internal fixation with iliac crest bone graft with use of a carbon fiber plate. The carbon fiber hardware facilitated clearer visualization of the allograft–native bone interface to assess for subsequent bony union.

Figure 4

(A) Pre-operative anteroposterior (AP) and lateral radiographs of the right distal femur, demonstrating a lesion in the distal metadiaphysis. (B) Pre-operative post-contrast, T1 fat-suppressed coronal, sagittal, and axial magnetic resonance (MR) images of the distal femur further characterizing the high-grade dedifferentiated chondrosarcoma. Note is made of the cortical breach and extramedullary soft-tissue component. (C) Immediate post-operative AP and lateral radiographs of the right femur, demstatus post intercalary resection with allograft reconstruction utilizing a carbon fiber cephalomedullary nail and carbon fiber plate. (D) 15-month post-operative AP and lateral radiographs of the right femur, demonstrating allograft non-union and hardware loosening. (E) The 6-week post-operative AP and lateral radiographs of the right femur status-post removal of the carbon fiber plate and non-union revision open reduction internal fixation with iliac crest bone graft with use of a carbon fiber plate. The carbon fiber hardware facilitated clearer visualization of the allograft–native bone interface to assess for subsequent bony union.

Figure 5

(A) Pre-operative T1 post-contrast, fat-saturation coronal and axial magnetic resonance (MR) images showing a large, enhancing tissue mass on the left proximal humerus without marrow involvement. (B) The 1-month post-operative AP and lateral radiographs following left humerus intercalary resection and allograft reconstruction with carbon fiber plate and cortical screws demonstrating incomplete fusion between the allograft and the native humerus. (C) The 8-month post-operative coronal and sagittal computed tomography (CT) images showing partial fusion. The carbon fiber plate facilitated visualization of the site of allograft and native humerus fusion status.

Figure 6

(A) Pre-operative AP and lateral radiographs demonstrating prior segmental resection of the proximal right tibia with allograft secured with a medial plate and multiple screws. (B) Pre-operative coronal and axial computed tomography (CT) images demonstrating potential hardware failure and concern for allograft fracture. (C) Immediate post-operative AP and lateral radiographs showing carbon fiber intramedullary rod in place and transposed vascularized fibular autograft secured with two screws. Note is made of one broken screw fragment from her prior operation that was retained in the proximal tibia. (D) AP and lateral radiographs 4-months post-operatively demonstrating a new unicortical allograft fracture after mechanical fall. (E) AP and lateral radiographs 8-months post-operatively bridging callus at the site of the mid-tibial unicortical allograft fracture. (F) AP and lateral radiographs 2-years post-operatively showing healed mid-tibial unicortical allograft fracture.