Recently, Cover News reported on a case of 3D printed individualized vertebral body replacement and reconstruction surgery for a lumbar multi-segmental total vertebrae resection. The team of Professor Li Tao from the Orthopaedic Spine Surgery Centre at West China Hospital, Sichuan University, removed the whole lumbar vertebrae full of tumours from the patient Mr Li and reconstructed his artificial vertebrae with 3D printing technology, minimising the risk of tumour recurrence and preserving function.

It is reported that this is the first case of 3D printed individualised artificial vertebral body replacement and reconstruction surgery for multi-segmental whole lumbar spine resection in the southwest. Professor Li Tao's team, in conjunction with the multidisciplinary departments of vascular surgery, anaesthesia, operating theatre, ICU and rehabilitation, successfully completed the surgery after two phases totalling 22 hours of surgery.

Patient profile

According to Cover News, Mr Li, 47 years old, sought medical attention seven months ago for low back pain and anterolateral numbness and pain in his right femur. After a series of tests, it was discovered that Mr. Li had chordoma growths in the 2nd, 3rd and 4th vertebrae of his lumbar spine. The lumbar 2 vertebral tumour was growing into the spinal canal and had compressed the spinal nerves in the spinal canal, producing cauda equina cone damage; the lumbar 3 vertebral tumour was growing into the abdominal cavity, forming a large soft tissue mass. Chordoma is a rare malignant tumour that occurs in the skull base, spinal column and sacrum, with an incidence of approximately 0.8 cases per 1 million people per year and a 5-year survival rate of only approximately 30% without effective treatment. Because chordoma is prone to local infiltration and invasion and is insensitive to conventional radiotherapy, surgery is the main treatment modality. However, it is extremely prone to recurrence after surgery, and when it does, it often leads to incontinence, paralysis of the lower limbs and even death. Therefore, the ability to remove the tumour completely during the initial surgery is key to the treatment of chordoma.

For Mr. Li, there were only 5 vertebrae in the lumbar spine and 3 were involved by the tumour, which equated to the tumour having invaded 3/5 of the entire lumbar spine. a total excision of the entire 3 vertebrae was almost the only hope for the patient to be saved.

However, the operation was very difficult. Firstly, in order to minimise the recurrence of the tumour, the whole vertebral block had to be removed, and the difficulty lay in the complete separation of the intervertebral ventricular structures. The spine is located in the back of the body and is surrounded by complex anatomy, many important organs and organs, adjacent to the largest blood vessels in the body and containing important spinal cord nerve structures, making the surgery risky. It is also the most difficult and technically demanding surgery in the field of spinal surgery, and only a few of the best hospitals in China are able to perform this type of surgery. Secondly, the tumour involves a long and extensive range of lumbar spine segments; at different segments, the tumour breaks through the intervertebral compartment to form a huge soft tissue mass in the spinal canal and paravertebral area, which involves a wide range of areas.

At the same time, tumour removal alone is not enough. Because the length of the spinal defect is very large after resection, and the defect site is the body's most stress-loaded medial bone, the biomechanical environment is complex, and traditional titanium mesh, braces and other implants are prone to fracture and displacement. The preservation of spinal cord nerve function is also a major challenge. The patient had already shown significant cauda equina cone damage before surgery, indicating that the spinal cord nerves had reached their limit of compression by the tumour. It was difficult to fully preserve spinal cord nerve function by performing such a large tumour resection and reconstruction surgery at the limit of the spinal cord nerves.

3D printed prosthesis for effective reconstruction of the vertebral body

Faced with such a difficult operation, Professor Li Tao's team carefully designed a 3-stage two-stage surgical treatment plan of "posterior - anterior - posterior again". The lumbar 2-4 vertebral attachments and discs were first removed through a lumbar back incision and fixed with pedicle screws and titanium rods to reconstruct the posterior structure of the lumbar spine; an anterior mid-umbilical incision was then made to separate the inferior vena cava, abdominal aorta and iliac artery vasculature, expose the tumour vertebral body and release the nerves layer by layer, completely remove the diseased vertebral body and tumour, and reconstruct the anterior vertebral structure; finally, the original incision was made through the lumbar back to connect the anterior artificial vertebral body The lumbar spine is then reconstructed through the original incision in the lumbar back by connecting the anterior artificial vertebral body to the posterior nail bar fixation system.

The surgery was successfully completed in two phases and took a total of 22 hours, with multidisciplinary collaboration between Professor Li Tao's team, including vascular surgery, anaesthesia, theatre, ICU and rehabilitation.

To achieve effective reconstruction of the anterior vertebral body, Professor Li Tao's team used 3D printing technology to produce an individualised artificial vertebral body. It is personalised according to the patient's anatomy and is designed to perfectly fit the upper and lower normal vertebral junction surfaces. The 3D porous titanium printing design provides sufficient biomechanical strength for the artificial vertebral body. In addition, specially designed screw implant holes allow the artificial vertebral body prosthesis to be attached to the posterior nail bar system, forming a unique truss structure that increases the stability of the artificial vertebral body, allowing the patient to get out of bed for rehabilitation as early as possible and achieve a normal-like life and work. It is understood that this is the first time a 3D printed individualised long-segment truss structure artificial vertebral body has been used in clinical practice in the southwest.

After the operation, Mr Li was able to wear a lumbar support to get out of bed under the care of medical staff and gradually recovered. Follow-up imaging showed no residual tumour and the internal fixation and artificial vertebral body were in good position. Mr Li was successfully discharged from hospital on 8 May.