Surgical treatment of post-traumatic luxation of rib heads with spinal cord compression in a cat

Background Luxation of the rib head with intrusion into the intervertebral foramen seems to be rare in cats. Only one report has been published describing a cat with non-ambulatory paraparesis, which was managed conservatively. Here we report a case of rib head luxation that was managed surgically. Case presentation A 4-year-old, female domestic shorthair cat with a two-week history of non-ambulatory paraparesis was presented at our clinic. Based on history and neurological examination, a diagnosis of thoracolumbar spinal cord lesion of traumatic origin was made. Computed tomography scanning revealed mild scoliosis, a luxation of the 3rd and 4th right rib heads and penetration into the spinal canal through intervertbral foramina. Surgical management using right dorsal approach to the spine was performed. The spinal cord was decompressed by cutting and removing of proximal ribs’ fragments by rotation and pulling out from the intervertebral foramina. The cat was ambulatory and paraparetic four weeks after surgery. Two years after surgery the cat regained functional gait, but ataxia remained. Conclusions We report the first case of a surgical treatment of rib head luxation and intrusion into the spinal canal in a cat. The applied procedure resulted in an improvement of neurological signs.

Could Screw/Hook Insertion at the Apical with Rib Head Dislocation Effectively Retract the Corresponding Rib Head from Spinal Canal in Dystrophic Scoliosis Secondary to Type 1 Neurofibromatosis?

Background. Rib head dislocation (RHD) in dystrophic scoliosis of type 1 neurofibromatosis (DS-NF1) is a unique disorder caused by skeletal dystrophy and scoliotic instability. No particular surgical manipulation is mentioned in the literature to instruct the spine surgeons to effectively obtain more migration of the dislocated rib head without resection. The present study aimed to investigate the effectiveness of screw/hook insertion at vertebrae with RHDs on the retraction of penetrated rib head from spinal canal.Methods. 37 neurologically intact patients with DS-NF1 and concomitant 53 RHDs undergoing scoliosis surgery without rib head excision were retrospectively reviewed. We used pre and postoperative whole-spine radiographs to determine the Cobb angle and the vertebral translation (VT), and the CT scans to evaluate the intraspinal rib length (IRL) and rib-vertebral angle (RVA). The dislocated ribs were stratified into two groups according to the presence of screw/hook insertion at vertebrae with RHD: screw/hook group and non-screw/hook group. Results. 37 dislocated ribs with screws/hooks insertion at corresponding vertebrae were assigned into the screw/hook group and the remaining 16 dislocated ribs consisted of the non-screw/hook group. In the screw/hook group, the correction rates of Cobb angle and VT were significantly higher than the non-screw/hook group after surgery (58.7±16.0% vs. 30.9±12.4%, p=0.003; 61.8±18.8% vs. 35.1±16.6%, p=0.001; respectively). Similarly, more correction rates of IRL and RVA were found in the screw/hook group than the non-screw/hook group (63.1±31.3% vs. 30.1±20.7%, p=0.008; 17.6±9.7% vs. 7.2±3.6%, p=0.006; respectively). Multiple linear regression analysis revealed that the correction rates of Cobb angle, VT and RVA contributed significantly to correction of IRL (β=0.389, 0.939 and 1.869, respectively; p=0.019, 0.001 and 0.002, respectively).Conclusion. Screw/hook insertion at dystrophic vertebrae with RHDs contributed significantly to the degree of retraction of penetrated rib head from spinal canal. This effectiveness is mediated by more corrections of VT and RVA.

Gorham-Stout disease of the spine presenting with intracranial hypotension and cerebrospinal fluid leak: A case report and review of the literature

Background: Gorham-Stout (GS) disease or “vanishing bone disease” is rare and characterized by progressive, spontaneous osteolysis resulting in loss of bone on imaging studies. Treatment modalities include combinations of medical and/or surgical treatment and radiation therapy. Case Description: A 14-year-old female with GS disease presented with a 1-year history of thoracic back pain and atypical headaches consistent with intracranial hypotension. Magnetic resonance imaging and operative findings demonstrated a spontaneous thoracic cerebrospinal fluid leak (CSF) (e.g., that extended into the pleural cavity) and complete osteolysis of the T9-10 posterior bony elements (e.g., including the rib head, lamina, and transverse processes). The patient underwent repair of CSF fistula followed by a T6-11 instrumented fusion. Conclusion: This case of GS disease, involving a thoracic CSF fistula and absence/osteolysis of the T9-T10 bony elements, could be successfully managed with direct dural repair and an instrumented T6-T11 fusion.

Traumatic rib head subluxation through the intervertebral foramen causing spinal cord contusive injury in a cat

Case summary A 4-year-old cat involved in a road traffic accident presented with paraparesis, which was worse on the right-hand side. Neurolocalisation was to the T3–L3 spinal cord segments. Survey radiographs showed rib fractures but no definitive diagnosis for the paraparesis. CT revealed fracture of the dorsal rim and a T9 rib subluxation through the intervertebral foramen at T8–T9. This caused a contusive spinal injury. Treatment consisted of rest and analgesia. The cat recovered well, with the owner reporting no abnormalities 5 months following the injury. Relevance and novel information Road traffic accidents are a common cause of injury in the cat population, with a significant number having thoracic injuries. These include rib injures such as fractures. This is the first reported case of a traumatic rib subluxation causing a contusive injury in the spinal cord of any species. Previously reported rib subluxations have been seen in humans with spinal deformities. Conservative management in this case was sufficient.