Femoral fracture unmasking dedifferentiated chondrosarcoma: A 52-year-old's diagnosis

• 52 year-old man
• Suffering bilateral leg pain for several months, diagnosed as a sciatic on the left side and as a truncated cruralgia on the right side.
• The compressive herniated disc L4/L5 was operated on the 30/01/2023
• A spontaneous, non-traumatic, fracture of the right femoral shaft occurred during the immediate post-operation manipulation (30/01/2023)
• The X-ray showed a pathological diaphyseal fracture of the right femur

Further exams were done (CT, MRI, TEP-scan) and the case was discussed during the oncologic pluri-disciplinary meeting.

A biopsy of the lesion was done on the 10/02/2023, the analysis concluded to a dedifferentiated chondrosarcoma.

How would you manage this condition?

• ✔️Radiological biopsy, oncologic treatment and later removal and reconstructive tumoral surgery

Final strategy decision

• After anatomopathological results of the biopsy and discussion at the oncologic pluri-disciplinary meeting treatment plan was set up with neoadjuvant chemotherapy followed by surgery
• A trans-tibial traction of the leg was done, to try to relieve the fracture pain during the medical treatment time
• The follow-up scan at 4 months showed a very limited evolution of the tumor, without obvious regression and without consolidation of the fracture
• The operation was planned for 29/06/2023

Surgery 06/2023

• A monobloc resection of the tumor was made with a femur proximal section at 7cm distal to the small trochanter and a distal section at 12cm of the interlining joint of the knee
• An important muscle portion of the quadriceps was removed
• The diaphysis was then reconstructed with a masquelet technique, divided into an endo-osteal and an extra-osteal fixation.
• For the internal fixation of the masquelet we used 2 Fuse-3D implants impacted in the proximal and distal remaining diaphysis of the femur and 3 spindles diameter 1,5, length 40cm were fixed inside and surrounded by wire cerclage
• For the external fixation of the masquelet we used a lateral femur plate fixed by 11 screws (7 fixed in the remaining bone, 4 fixed in the masquelet)
• Around this montage, cement was sunk

Per-op pictures

Post-op x-rays

Patient follow-up

• Anatomopathological results: R0, with bad chemotherapy response
• Pulmonary metastases were discovered and no reconstruction is scheduled for now
• Clinically: able to stand up and walk for a few steps with a walker