RU2800564C1 - Method for surgical treatment of atlantoaxial instability - Google Patents

Abstract

FIELD: medicine; neurosurgery; orthopedics.

SUBSTANCE: invention can be used in the surgical treatment of adults and children with atlantoaxial instability. The method includes cutting the skin and subcutaneous tissue along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae, opening the capsules of the atlantoaxial joints along their posterior surface, removing the hyaline plates of the articular surfaces of the atlantoaxial joints, repositioning the deformity and distraction of the atlantoaxial joints under conditions of drug relaxation, introduction of tricortical autologous iliac bone grafts into the interarticular spaces, posterior screw fixation of C1-C2 vertebrae, layer-by-layer wound closure. At the same time, during the method, the posterior edges of the upper articular facets of the C2 vertebra and the anterior edges of the lower articular facets of the C1 vertebra are resected until a parallel orientation of the articular spaces of the atlantoaxial joints relative to the axial plane of the body is achieved. Tricortical autobone grafts formed from the iliac crest are inserted into the interarticular fissures of the atlantoaxial joints.

EFFECT: method provides increased efficiency of treatment by providing fixation of the atlantoaxial joints and increasing the frequency of bone block formation in the spondylosynthesis zone.

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Description

The invention relates to medicine, namely to neurosurgery and orthopedics, and can be used in the surgical treatment of adults and children with atlantoaxial instability.

A known method of surgical treatment of atlantoaxial instability, which consists in open reposition of the deformity followed by C1-C2 fixation (Yin YH, Qiao GY, Yu XG, Tong HY, Zhang YZ. Posterior realignment of irreducible atlantoaxial dislocation with C1-C2 screw and rod system: a technique of direct reduction and fixation Spine J. 2013 Dec 13(12): 1864-71 doi: 10.1016/j.spinee.2013.08.014 Epub 2013 Oct 30 PMID: 24183463.), in which the skin and subcutaneous fiber along the line of the spinous processes, skeletonize the spinous processes and arches of C1 and C2 vertebrae. Under conditions of drug relaxation, the deformity is repositioned. The main stage of the operation is completed with posterior screw fixation of C1-C2 vertebrae. The wound is sutured in layers.

The disadvantages of the method:

- preservation of capsules and hyaline plates of C1-C2 joints;

- preservation of deformation of the articular surfaces of C1 and C2 vertebrae;

- lack of primary stability of the C1-C2 vertebrae. In the postoperative period, this causes the impossibility or an increase in the time for the formation of bone union over the area of the articular surfaces, the preservation of conditions for the anterior translation of the C1 vertebra due to reliance on deformed and anteriorly inclined articular surfaces, and an increased load on the fixing structure. The development of these consequences, due to the technique of performing this method of treatment, has a significant impact on the quality of life of the patient and in some cases requires repeated surgical treatment due to instability of fixation and recurrence of deformity.

Closest to the claimed is a method of surgical treatment of atlantoaxial instability (Goel A, Shah A. Atlantoaxial joint distraction as a treatment south basilar invagination: a report of an experience with 11 cases. Neurology India. 2008; 56:144. https://doi .org/10.4103/0028 - 3886.41991) taken as a prototype. In a known method, the skin and subcutaneous tissue are dissected along the line of the spinous processes, the spinous processes and arches of C1 and C2 vertebrae are skeletonized. The capsules of the atlantoaxial joints are opened along its posterior surface, the articular surfaces are dehyalinized - the hyaline plates of the articular surfaces of the atlantoaxial joints are removed. Under conditions of drug relaxation, the deformity is repositioned. Autologous bone grafts are inserted into the interarticular spaces of the atlantoaxial joints. The main stage of the operation is completed with posterior screw fixation of C1-C2 vertebrae. The wound is sutured in layers.

The disadvantages of the prototype are:

- preservation of deformation of the articular surfaces of C1 and C2 vertebrae;

- the implant is supported by the cortical layer of the endplates of the atlantoaxial joints;

In the postoperative period, this leads to the preservation of conditions for the anterior translation of the C1 vertebra due to support on the anteriorly beveled articular surfaces, an increased load on the fixing structure, the impossibility or an increase in the formation of bone union over the area of the articular surfaces, and the creation of conditions for delayed destabilization of the fixing structure due to contact osteolysis against the background of slow consolidation of the vertebrae in the zone of osteosynthesis. The development of these consequences, due to the technique of performing this method of treatment, has a significant impact on the quality of life of the patient and in some cases requires repeated surgical treatment due to instability of fixation and recurrence of deformity.

The technical problem to be solved by the invention is to create a method for the surgical treatment of atlantoaxial instability, providing an increase in the effectiveness of treatment by ensuring the fixation of the atlantoaxial joints and increasing the frequency of formation of a bone block in the spondylosynthesis zone, which in turn reduces the duration of treatment.

The technical problem is solved due to the fact that in the claimed method, including dissection of the skin and subcutaneous tissue along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae, opening the capsules of the atlantoaxial joints along their posterior surface, removing the hyaline plates of the articular surfaces of the atlantoaxial joints, repositioning of the deformity and distraction of the atlantoaxial joints under conditions of medical relaxation, insertion of tricortical autologous iliac bone grafts into the interarticular spaces, performing posterior screw fixation of C1-C2 vertebrae, layer-by-layer suturing of the wound, according to the invention, the posterior edges of the upper articular facets of the C2 vertebra and the anterior edges of the lower articular facets are resected C1 vertebra until the parallel orientation of the articular spaces of the atlantoaxial joints relative to the axial plane of the body is reached, tricortical autobone grafts formed from the iliac crest are inserted into the interarticular spaces of the atlantoaxial joints. The main stage of the operation is completed with posterior screw fixation of C1-C2 vertebrae. The wound is sutured in layers.

Thus, the conditions for the formation of bone union in the area of spondylosynthesis are improved due to the support of the tricortical autologous graft on partially decorticated articular surfaces under conditions of posterior screw stabilization of C1-C2 vertebrae. This reduces the load on the fixing structure due to the correction of the angle of inclination of the joint space, which leads to an increase in the reliability of spondylosynthesis.

The method is carried out as follows. Dissection of the skin and subcutaneous tissue is performed along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae, the capsules of the atlantoaxial joints are opened along their posterior surface, the hyaline plates of the articular surfaces are removed; the edges of the upper articular facets of the C2 vertebra and the anterior edges of the lower articular facets of the C1 vertebra until a parallel orientation of the articular spaces of the atlantoaxial joints relative to the axial plane of the body is achieved. Tricortical autobone grafts formed from the iliac crest are inserted into the interarticular spaces of the atlantoaxial joints. The main stage of the operation is completed with posterior screw fixation of C1-C2 vertebrae. The wound is sutured in layers.

The inventive method has passed clinical trials in the treatment of 4 adult patients and 6 pediatric patients with atlantoaxial instability. 1 adult patient and 2 pediatric patients were operated on again due to instability of the previously performed fixation and recurrence of atlantoaxial instability. In all patients, during the preoperative examination, a violation of the tropism of the articular surfaces of the atlantoaxial joints was noted due to their unilateral or bilateral anterior angulation. In all patients, it was possible to achieve primary stabilization of the operated segments; in all patients, regression of vertebrogenic pain syndrome and torticollis was noted. All patients were discharged in a satisfactory condition 5-7 days after surgery. There were no infectious complications in any of the cases. Clinical results are tracked for more than two years. None of the patients had recurrence of pain syndrome and recurrence of torticollis during the follow-up period. In all patients, in the period from 3 to 5 months, the formation of bone fusion was noted in the area of spondylosynthesis. There were no signs of destabilization of the stabilizing structure in any patient.

The method is illustrated by the following clinical examples. Example 1. Patient D., born in 2018. Diagnosis: Anomaly of segmentation of the C2 vertebra. Tooth bone. Fixed atlantoaxial instability (Fielding&Hawkins 2). Stenosis of the spinal canal at the level of C1 vertebra. Compression-ischemic myelopathy at the level of the upper cervical segments of the spinal cord. Mixed tetraparesis. Arthrogenic torticollis. Down Syndrome.

Anamnesis of the disease: since April 2021, torticollis appeared. Conservative treatment with a positive effect. In September 2021, a recurrence of torticollis, mixed tetraparesis, stopped walking from the end of September.

Upon admission, the general condition was severe, the severity was due to a pronounced neurological deficit. Somatically compensated, without gross somatic pathology. The neurological status is represented by mixed tetraparesis - flaccid predominantly proximal in the arms up to 3 points; spastic proximal 3 points, distally up to 2 points in the legs. The functions of the pelvic organs are not impaired. Forced fixed head position with tilt and rotation to the right.

MPT of the cervical spine from 08/18/2021: anomaly in the development of the craniovertebral zone. Dentoid bone C2 vertebra. Anterior transdental translation of the C1 vertebra, complete rotational dislocation of the left lateral mass of the C1 vertebra. The spinal canal at the level of C1-C2 is narrowed to 2 mm. CT scan of the cervical spine dated October 31, 2021: complete rotational dislocation of the left lateral mass of the C1 vertebra. Anterior transdental translation of the C1 vertebra against the background of the odontoid bone of the C2 vertebra. The deformation of the articular surfaces of both atlantoaxial joints with their anterior angulation, more pronounced on the left, is determined.

Given the presence of gross deformity and stenosis of the spinal canal at the C1-C2 level, confirmed by neuroimaging data, clinically manifested by severe decompensated neurological and orthopedic deficits, the ineffectiveness of conservative treatment, in order to stop the leading clinical manifestations, a planned surgical intervention was performed on November 12, 2021: spinal cord decompression, correction atlantoaxial deformity, bilateral C1-C2 arthrodesis with autobone, posterior screw fixation of C1-C2 vertebrae. According to the claimed method: dissection of the skin and subcutaneous tissue along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae. The capsules of the atlantoaxial joints were opened along their posterior surface, the hyaline plates of the articular surfaces of the atlantoaxial joints were removed. Under conditions of medical relaxation, deformity reposition and distraction of the atlantoaxial joints were performed. The posterior edges of the superior articular facets of the C2 vertebra and the anterior edges of the inferior articular facets of the C1 vertebra were resected until the articular spaces of the atlantoaxial joints were oriented parallel to the axial plane of the body. Tricortical autologous bone grafts formed from the iliac crest were introduced into the interarticular fissures of the atlantoaxial joints. Performed posterior screw fixation of C1-C2 vertebrae. The wound was sutured in layers.

The postoperative period was uneventful, the neurological status showed partial regression of tetraparesis, regression of torticollis. The sutures were removed on the seventh day, the wound healed by primary intention.

On postoperative control computed tomograms of the cervical spine, satisfactory correction of the deformity - the axis of the odontoideum is parallel to the axis of the C2 vertebral body, the articular surfaces of the C1 and C2 vertebrae are parallel, tricortical autobone grafts are installed in the interarticular gaps. The spinal canal at the level of C1-C2 is not narrowed. Fixing screws were inserted transpedicularly bilaterally into the lateral masses of the C1 vertebra and into the body of the C2 vertebra. The position of the screws and autologous grafts is satisfactory.

On the control computed tomograms of the cervical spine 3 months after surgical treatment, the achieved correction was preserved, the position of the fixing screws was correct, without signs of instability. In the zone of arthrodesis of the atlantoaxial joints, a bone fusion is formed.

Example 2. Patient M., 43 years old. Diagnosis: An old fracture of the odontoid process of the C2 vertebra, type 2 according to Anderson-Alonzo. Anterior transdental dislocation of the C1 vertebra with severe local kyphotic deformity of the C1-C2 segment and secondary stenosis of the spinal canal at this level. Atlantoaxial instability. Compression-ischemic myelopathy at the level of the upper cervical spinal cord.

Anamnesis of the disease: in 2010, a fall at a construction site. On this occasion, he was not treated and was not examined. Two years later, he notes the appearance of intense pain in the cervical region, in the occipital region. The pain intensified with sudden movements in the cervical spine. Gradually, he began to notice an increase in weakness in the arms, more on the left, then in the legs. There was a decrease in sensitivity in the occipital region and in the hands. Periodically noted increased urination, choking when eating, hoarseness. He underwent conservative treatment in 2020 - without a positive effect. According to MRI of the cervical region, signs of an old unstable fracture of the C2 tooth with ventral displacement and rotation to the left of the C1 vertebra, compression of the spinal cord, and myelopathy were revealed.

Upon admission, the general condition of moderate severity, the severity is due to a pronounced neurological deficit. Somatically compensated, without gross somatic pathology. The neurological status is represented by mixed tetraparesis - flaccid predominantly proximal in the hands up to 2 points on the right, 3 points on the left; spastic proximally 4 points, distally up to 3 points in the legs. The functions of the pelvic organs are imperative urges. Laterocollis on the left.

MRI of the cervical spine from 09/20/2020: consequences of a fracture of the C2 odontoid process of the vertebra type 2 according to Anderson. Post-traumatic stenosis of the spinal canal with signs of myelopathy at the level of C1-C2 due to ventral compression of the spinal cord against the background of atlantoaxial instability with anterior transdental dislocation of the C1 vertebra.

Given the presence of gross deformity and stenosis of the spinal canal at the C1-C2 level, confirmed by neuroimaging data, clinically manifested by severe decompensated neurological and orthopedic deficits, the ineffectiveness of conservative treatment, in order to stop the leading clinical manifestations, a planned surgical intervention was performed on November 19, 2021: spinal cord decompression, correction atlantoaxial deformity, bilateral C1-C2 arthrodesis with autobone, posterior screw fixation of C1-C2 vertebrae. According to the claimed method: dissection of the skin and subcutaneous tissue along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae. The capsules of the atlantoaxial joints were opened along their posterior surface, the hyaline plates of the articular surfaces of the atlantoaxial joints were removed. Under conditions of medical relaxation, deformity reposition and distraction of the atlantoaxial joints were performed. The posterior edges of the superior articular facets of the C2 vertebra and the anterior edges of the inferior articular facets of the C1 vertebra were resected until the articular spaces of the atlantoaxial joints were oriented parallel to the axial plane of the body. Tricortical autologous bone grafts formed from the iliac crest were introduced into the interarticular fissures of the atlantoaxial joints. Performed posterior screw fixation of C1-C2 vertebrae. The wound was sutured in layers.

The postoperative period was uneventful, the neurological status showed partial regression of tetraparesis, regression of torticollis. The sutures were removed on the fifth day, the wound healed by primary intention.

On postoperative control computed tomograms of the cervical spine, satisfactory correction of the deformity - the angle between the axis of the C2 odontoid process and the axis of the C2 vertebral body is 5 degrees, the articular surfaces of the C1 and C2 vertebrae are parallel, tricortical autobone grafts are installed in the interarticular gaps. The spinal canal at the level of C1-C2 is not narrowed. Fixing screws were inserted transpedicularly bilaterally into the lateral masses of the C1 vertebra and into the body of the C2 vertebra. The position of the screws and autologous grafts is satisfactory.

On the control computed tomograms of the cervical spine 3 months after surgical treatment, the achieved correction was preserved, the position of the fixing screws was correct, without signs of instability. In the zone of arthrodesis of the atlantoaxial joints, a bone fusion is formed.

The use of the proposed method for the surgical treatment of atlantoaxial instability makes it possible to perform correction and primary stable fixation of the atlantoaxial instability zone. At the same time, due to the correction of the angle of inclination of the joint space, the load on the fixing structure is reduced, which leads to an increase in the reliability of spondylosynthesis. Partial resection of the cortical layer of the endplates with exposure of the spongy bone of the articular processes providing support for the tricortical autologous graft on the partially decorticated articular surfaces provides optimal conditions for the formation of bone union in the spondylosynthesis zone without the threat of delayed loss of fixation and contact osteolysis.

Claims (1)

A method for surgical treatment of atlantoaxial instability, including dissection of the skin and subcutaneous tissue along the line of the spinous processes, skeletonization of the spinous processes and arches of C1 and C2 vertebrae, opening the capsules of the atlantoaxial joints along their posterior surface, removal of the hyaline plates of the articular surfaces of the atlantoaxial joints, repositioning of the deformity and distraction of the atlantoaxial joints under conditions of drug relaxation, the introduction of tricortical autologous iliac bone grafts into the interarticular spaces, the implementation of posterior screw fixation of the C1-C2 vertebrae, layer-by-layer suturing of the wound, characterized in that the posterior edges of the upper articular facets of the C2 vertebra and the anterior edges of the lower articular facets of the C1 vertebra are resected until parallel orientation of the articular spaces of the atlantoaxial joints relative to the axial plane of the body, tricortical autobone grafts formed from the iliac crest are inserted into the interarticular spaces of the atlantoaxial joints.