Five years ago, 23-year-old Xiaolin's cervical spine was repeatedly sore, her left hand was numb and her lower limbs were weak, and as her symptoms continued to worsen, it had seriously affected her work and life. Recently, Professor Yang Cao from the Department of Orthopedics of Union Hospital Affiliated to Huazhong University of Science and Technology led a team to independently design and develop a new laser 3D printed porous tantalum metal side block inter-articular fusion device for the treatment of skull base depression complicated with atlanto-occipital deformity and atlantoaxial dislocation, and successfully corrected torticollis deformity. This is also the first time in China to use a 3D printed porous tantalum metal side block inter-articular fusion device for the treatment of upper cervical deformity, and important breakthroughs and progress have been made in design concepts, technological innovation, and clinical applications.
Fig. 1 Actual image of a new 3D printed porous tantalum metal side block inter-articular fusion
The patient, Zhou Lin (pseudonym), a 28-year-old from Xianning, Hubei Province, suffered from torticollis and facial asymmetry when he was a child, and has not been taken seriously. 5 years ago, due to unexplained long-term soreness of the cervical spine, left hand numbness with lower limb weakness, symptoms aggravated in the past six months, seriously affecting work and life, she came to the outpatient clinic of Professor Yang Cao of the Department of Orthopedics of Union Hospital, and was later diagnosed with skull base depression + atlanto-occipital deformity + atlantoaxial dislocation, which is a complex head and neck junction deformity with high disability rate and mortality rate. The human cervical spine is divided into 7 segments, and the atlantoaxial vertebra is the first and second segments of the cervical vertebrae, surrounded by important nerves and blood vessels. Professor Yang Cao evaluated Zhou Lin's condition and found that the patient's spinal cord was compressed, which was very harmful, and recommended surgical treatment.
The general experts of the Department of Spine Surgery conducted a case discussion and formulated a detailed surgical plan: 3D printing was carried out on the patient's upper cervical vertebrae and vertebral artery, a three-dimensional geometric model of the atlantoaxial vertebra was established, and a porous tantalum metal side block inter-articular fusion device was implanted through the release of the atlantoaxial lateral block space, so as to restore the normal sequence of the craniocervical junction area, so as to relieve the compression of the dentate process on the extended spinal cord.
According to the preoperative CT data, Yang Cao's team designed personalized tantalum metal fuses of different sizes, and implanted fuses of different heights and widths in the joint space of the atlantoaxial lateral block, so as to "pull out" the odontoid process from the skull to achieve the purpose of atlantoaxial reduction and decompression, and at the same time correct the patient's torticollis deformity.
Professor Yang Cao's team fully considered the differences such as the surgical method and the implantation position of the fusion device to construct a simplified analysis model with approximate mechanical properties, and at the same time, with the help of surface structure topology optimization technology, the interface of the fusion device has excellent osteogenic performance, which is conducive to the long-term fusion effect, and finally designed an ideal 3D printed porous tantalum metal side block inter-articular fusion device.
The 3D printed model shows a skull base depression, atlanto-occipital deformity, atlantoaxial dislocation, elevated and coarse development of the left vertebral artery, winding posterior to the atlantovertebral lateral block, and dysplasia of the C2 pedicle on one side
On April 15, Professor Yang Cao's team carried out "posterior cervical atlantoaxial inter-block release reduction + 3D printed porous tantalum metal fusion implantation + occipital neck bone graft fusion internal fixation" for Zhou Lin, with a bleeding of less than 100ml and successfully completed the operation. After the operation, the patient recovered satisfactorily, the neurological symptoms and torticollis deformity were significantly improved, and he got out of bed to exercise one day after the operation.
Professor Yang Cao (first from right) during surgery
Postoperative X-ray and CT showed that the patient was well reduced, the position of the fusion device was satisfactory, the spinal cord compression was relieved, and the torticollis deformity was corrected.
Skull base depression is a complex craniocervical junction deformity, which is mainly caused by the skeletal tissue around the foramen magnum trapped in the cranial cavity, often combined with atlantoaxial dislocation, Klippel-Feil syndrome, Chiari malformation, syringomyelia, atlanto-occipital and other deformities. Skull base depression combined with atlantoaxial dislocation is clinically classified as type A. After dislocation, the odontoid process enters the foramen magnum posteriorly and upward, compressing the medulla, spinal cord or cranial nerves, causing sensory, motor, sphincter dysfunction, and even leading to the death of the patient, requiring surgical treatment.
According to Professor Yang Cao, skull base depression and atlantoaxial dislocation (type A skull base depression disease), which is released through posterior lateral interblock release and implantation of 3D printed tantalum metal fusion device, is the first operation in China to deal with complex craniocervical and vertebraic junction diseases, providing a new option.
Professor Yang Cao's team and the interdisciplinary scientific and technological research and development team crossed over and used a new 3D printed porous tantalum metal side block inter-articular fusion device for the treatment of upper cervical deformity. The new 3D printed tantalum metal fusion device was designed and invented by Professor Yang Cao. Professor Yang Cao's team will continue to devote itself to the research and development of 3D printed personalized bionic intraspinal implants, further improve the economy and universality of 3D printed intraosseous implants, relieve the pain of patients with spinal diseases, and contribute to the medical technology of orthopedic implants in mainland China.
Source: Union Hospital Affiliated to Huazhong University of Science and Technology
Correspondents: Chen Youwei and Feng Xiaobo
Editor: Huang Menglin
Reviewer: Chen Shirui
Issued: Daley Red
Picture: Some of the pictures in this article are from the Internet, the copyright belongs to the original author, if there is any infringement, please contact us to delete.