Use of a three-dimensional-printed spine model for surgical planning in a feline vertebral chondroblastic...

A 2-year-old, male neutered domestic shorthair cat presented with a 1-month history of non-specific pain and inappetence, left-sided Horner syndrome, pelvic limb proprioceptive ataxia, upper motor neuron paraparesis and a plantigrade stance. Advanced imaging revealed a heterogeneous contrast-enhancing extradural mass dorsal to the T1-T2 intervertebral disc space, causing severe left-sided spinal cord compression. Medical image processing software was used to generate a patient-specific three-dimensional spine model based on MRI and CT data. A biomechanical three-dimensional-printed replica of the T1-T3 region allowed preoperative simulation of a left-sided hemilaminectomy and mass removal, confirming contiguity of the lesion with the T1 vertebral body and extension along the vertebral canal to T2-T3. The model aided intraoperative landmark identification and facilitated safe and effective spinal cord decompression. Histopathology from surgical biopsy was most consistent with either chondroblastic osteosarcoma or chondrosarcoma. Postoperative radiation therapy was initiated but discontinued owing to difficulties establishing reliable intravenous access. Progressive neurologic deterioration eventually led to euthanasia. Post-mortem CT and necropsy confirmed a diagnosis of chondroblastic osteosarcoma without evidence of metastatic disease. The cat had a survival time of 356 days after surgery (387 days from initial presentation).

This report describes the first known vertebral chondroblastic osteosarcoma in a cat. It highlights the value of biomechanical three-dimensional-printed spine models for preoperative planning in complex vertebral surgery and demonstrates that tumor debulking, even when combined with incomplete radiotherapy, can provide meaningful palliation and prolonged survival. Further studies are needed to define optimal treatment strategies and prognosis for feline vertebral osteosarcoma subtypes.