From this analysis, a method of cervical pedicle screw placement based on topographic anatomy was developed. Posterior stabilization of the cervical spine with lateral. An image analysis kuanyin tseng, chungching hsia, yuanhao chen, shini ma, chitun tang department of neurological surgery, triservice general hospital, taipei 114, taiwan, china. The medial cortical pedicle screwa new technique for. Objectives direct c1 lateral massc2 pars or pedicle screw fixation has been recently proposed as an alternative method to. In that same study, no patient in the lateral mass screw group had loss of reduction or the need for implant removal compared with one patient 3. Halo application, posterior wiring, and c1 to c2 transarticular screws have been used to stabilize the upper cervical spine. Cervical pedicle screws versus lateral mass screws. The use of the minipolyaxial screws is limited to placement in the cervical and upper thoracic spine c1t3. Posterior screw fixation utilizing c1 c2 transarticular screws and c1 lateral mass screws with c2 pars screws were the final two alternative methods of posterior c1c2 fixation. Pdf posterior cervical lateral mass screw fixation researchgate. A case is presented in this for easier understanding. Conclusion lateral mass fixation can be applied easily and safely for all levels of subaxial cervical spine from c3 to c6 with the following parameters. Objectives to determine the clinical safety of lateral mass screws by determining their anatomic location and clinical complications in a consecutive patient series.
The use of c1 lateral mass screws in complex cervical spine. Leconte first reported c2 pedicle screw insertion for osteosynthesis of the c2 hangmans fracture. The mountaineer oct spinal system can also be linked to the isola. In particular, tricks to avoid complications are presented. Although these systems are safe and reliable, they can be difficult to use in patients with abnormal cervical anatomy. Lateral mass screw lms fixation of the cervical spine is an important tool in the armamentarium of the spinal surgeon as it permits to associate a biomechanical sound instrumentation to a wide posterior decompression. In severe osteopeniaosteoporosis, lateral mass fixation may. Lateral mass screws lms and pedicle screws ps are the most commonly. In the second part of the study, 12 human cadaver cervical spines were instrumented with 3.
With time, many spine surgeons have adopted lateral mass screw lm fixation as representing the optimal balance between rigidity and safety for fixation in the subaxial cervical spine 5. This study evaluates the outcome and complications of decompressive cervical laminectomy and lateral mass screw fixation in 110 cases treated for variable cervical spine pathologies that included. Fracture separations of the lateral mass facet are uncommon injuries characterized by high degree of instability. Indications, techniques, and outcome in a prospective consecutive series of 25 cases. Sub axial cervical spine lateral mass screw fixation. Posterior cervical fixation with lateral mass screws. Lateral mass screw fixation of the subaxial cervical spine. The ideal screw entry point, direction, size and exit point are. Four lateral mass screw fixation techniques in lower. Misplaced lateral mass screw is not uncommon, and operationrelated complications still beset the surgeons, which may impair the clinical outcomes.
Posterior cervical screw placement without image guidance. Although the biomechanics of lateral mass and pedicle screw fixation of the subaxial cervical and upper thoracic spine are well described, there is no report comparing construct stability or screw pullout strength of translaminar, lateral mass, and pedicle screws in this region. Posterior cervical fixation using a new polyaxial screw. The purpose of this study was to compare pullout strengths of pedicle screws and lateral mass screws inserted into cervical. Posterior cervical laminectomy and fusion spine orthobullets. Cervical pedicle screw placement in sawbone models and. Cervical transfacet screw placement provides pullout resistance that is comparable to, if not greater than, lateral mass placement. This article explains in detail minimally invasive approaches to the posterior spine, the techniques for posterior cervical foraminotomy and arthrodesis via lateral mass screw placement, and anterior cervical foraminotomy. Lateral mass screw fixation of the cervical spine has been shown to be effective in adult patients. Clinical symptoms and asia classification were improved in all the patients.
Lateral mass plates and pedicle screws through posterior approach are safe and beneficial for patients with lower cervical spine. Posterior lateral mass screw fixation university of pennsylvania. It has the largest vertebral body and the longest spinous process in the cervical spine, but with a quite thin lateral mass compared with the other lateral masses from c3 to c6. The songer cable system, to be used with the mountaineer oct spinal system, allows for wirecable attachment to the posterior cervical spine. Posterior lateral mass plate fixation of the cervical spine. A possible complication of cervical lm screw placement is vertebral artery injury or impingement. The mean loadtofailure was 677 n for the cervical pedicle screws and 355 n for the lateral mass screws. This study establishes the threedimensional finite element model of the lower. Several methods of posterior cervical spine fixation have been described, including wiring, posterior plate and screw fixation and pedicle screw constructs 1, 2, 3, 4. The lnk cervical fixation system includes instrumentation and spinal implants for posterior spinal fixation in the c1t3 vertebral levels in the cervical and upper levels of the thoracic spine. Each technique has disadvantages, and c1 lateral mass fixation recently has gained popularity as a potential alternative.
The authors have used this system successfully, and without significant complications, to achieve posterior cervical arthrodesis. Posterior cervical arthrodesis and stabilization with a. Sub axial cervical spine lateral mass screw fixation saw model. The screws were cyclically loaded 200 times in the sagittal plane. Laminaguided lateral mass screw placement in the sub. A laminectomy is a procedure that removes some lamina and spinal processes at the back of the spinal canal to increase the space for, and decrease the pressure on, the spinal cord. Cervical lateral mass fracture separation spine orthobullets. The intervals of bilateral entry points and left and right lateral angles are obtained. The bone awl has a hard stop that limits insertion to 8 mm. Four lateral mass screw fixation techniques in lower cervical. Lateral mass screw fixation in sub axial cervical spine is a common technique in posterior cervical stabilisation. Screws placed in the pedicles of thoracic vertebra and in the lateral part of the cervical vertebra can be used to provide fixation for fusion across the low neck and upper thoracic spine. Despite increasing acceptance of the use of pedicle screws in the lumbar and thoracic spine, screw insertion into the cervical pedicle has been considered by spine surgeons to be too risky for the neurovascular structures, except at c2 and c7. Free hand technique of cervical lateral mass screw fixation ncbi.
Posterior cervical fixation techniques are commonly selected procedures in the surgical management of subaxial cervical spine diseases. Prospective, selfcontrolled, comparative study of transposterior arch lateral mass screw fixation and lateral mass screw fixation of the atlas in the treatment of atlantoaxial instability. Lateral mass screw placement viewed posteriorly, axially, and laterally. Sep 07, 2015 the best sleeping position for back pain, neck pain, and sciatica tips from a physical therapist duration. Posterior cervical lateral mass screw fixation nevada. Lateral mass lm screws are commonly used in posterior instrumentation of the cervical spine because of their perceived safety over pedicle screws. Lateral mass plating has become the technique of choice for posterior cervical fixation. The limitation of lateral mass screws as compared to. Pedicle screw fixation for nontraumatic lesions of the cervical spine. Use of spinous processes to determine the laterally angulated trajectory for placement of lateral mass screws. Cervical spine anterior and posterior fusion with intervertebral bone struts plugs young woman with traumatic locked facets at c67 and c7 body fracture. The c1 lateral mass screw with c2 pedicle screw construct was initially created with plates and screws by goel et al in the 1980s. Fda approval for use in the subaxial posteriorcervical spine. Cervical lateral mass screws for posterior fusion surgery.
These screws require an extremely precise positioning. Susceptibility artifact from cervical spine disk prosthesis. Safety and efficacy of lateral mass screws at c7 in the treatment of. There are 2 fixation techniques commonly used in the subaxial cervical spine.
How to insert a lateral mass screw into c6 duration. Oct 18, 2011 introduction the cervical spine is a highly mobile segment of the spinal column, liable to a variety of diseases and susceptible to trauma. Bailout screw placement in the posterior subaxial cervical. In the present study, lateral mass screwrod fixation avoided some of the limitations associated with plating systems. Dec 01, 2009 lateral mass lm screws are commonly used in posterior instrumentation of the cervical spine because of their perceived safety over pedicle screws. Aberrant posterior inferior cerebellar artery injury with. T2weighted sagittal magnetic resonance imaging may allow identification of neural compression and determination of the vascular anatomy figure 121.
To my fellow coders, my physician performed a wide cervical laminectomy at c3 to c6. This technical note describes the successful placement of lateral mass screw and rod constructs with the use of a minimally invasive approach by means of a tubular dilator retractor system. The overall goal of this in vitrostudy was to investigate the biomechanical differences between pedicle screw and lateral mass screw fixation in the subaxial cervical spine. A novel classification of screw placement accuracy in the cervical.
During the pedicle screw insertion, retracting dural sac by using microdissector, the pedicle should be visualized under the microscope figure 3. We agree with roche et al that the placement of lateral mass screws is safe and highly effective if, and only if, the surgeon is aware of neurovascular anatomy in the cervical spine and how to manage complications should they occur. Methodthe authors first describe the surgical anatomy of the subaxial cervical posterior approach. Direct c1 lateral mass screw for cervical spine stabilisation. He removed the spinous process which was later mixed with demineralized bone matrix and used in a bone graft.
This approach preserves the integrity of the muscles and ligaments that maintain the posterior tension band of the cervical spine. Surgical anatomy for pedicle screw placement in the cervical. Finecut 2mm computed tomography with twodimensional reconstruction allows assessment of the lateral mass quality in the lower cervical spine. Associated conditions anterior translation listhesis fractured vertebrae 77% superior adjacent vertebrae 24% inferior adjacent vertebrae 10% coronal translation 33% vertebral body collapse 33% lower in type a separation fracture subtypes. Despite the increasing acceptance among spine surgeons of the use of pedicle screws in the lumbar and thoracic spine, screw insertion into the cervical pedicle has been considered too risky for the surrounding neurovascular structures, except at c2 and c7.
Operative technique lateral mass screw fixation in sub. The medial cortical pedicle screwa new technique for cervical pedicle screw placement with partial drilling of medial cortex. However, there are situations when standard lateral mass screw placement is not possible. We used a kind of cervical pedicle screw system vertex, medtronic sofamor danek, memphis, tn, usa in all. Surgical anatomy for pedicle screw placement in the cervical spine tomomichi kajino, md, hiroshi taneichi, md, kota suda, md, kiyoshi kaneda, md bibai, japan introduction. The patient underwent a c36 laminectomy, c36 lateral mass, and c7 laminar screw placement. Articulo o rtigo a freehand placement of c7 pedicle screws. Pedicle and lateral mass dimensions were highly variable and not predictive of pullout strength. The use of c1 lateral mass screws in complex cervical spine surgery. Beware of patients with aberrant bony anatomy making screw placement difficult, such as those with erosive rheumatoid arthritis or osteoarthritis, or ectatic coursing of the vertebral artery.
Transpedicular screw fixation was first described in 1989 for the upper cervical spine 1,2, and five years later for the middle and lower cervical spine for traumatic lesions 3. C1 lateral mass is anatomically ideally suited for screw fixation to achieve c1c2 arthrodesis. In this report, we describe surgical technique for placement of c1 lateral mass screws, on our c1 specimen. Lower cervical spine injury treated with lateral mass. C1 lateral mass screw placement is a powerful technique for segmental control of the c1 vertebra. Cervical lateral mass screw fixation is indicated for the treatment of cervical subaxial c3c7 lesions associated with instability.
Safe placement of lateral mass screw in the subaxial cervical. The three techniques differ regarding their starting point in the mass, degree of divergence from the midline, and sagittal plane orientation relative to the facet joint. Anatomic consideration of transpedicular screw placement in the cervical spine. The amount of displacement was recorded every 50 cycles. There are only a few reports related to lsf applications, even though fracture fixation has become a severe complication. It is a complex region where many vital structures lie in close proximity. Computed tomography of the cervical spine confirmed the mr imaging findings as well as showed suboptimal lateral mass and pedicles for screw placement.
Indications and techniques of cervical pedicle screws c37. Decompressive cervical laminectomy and lateral mass screwrod. Jul 24, 2016 3 indications and techniques of cervical pedicle screws c37 for degenerative conditions. With the steady development of internal fixation techniques, lateral mass screw fixation lsf with plates or rods has become the standard method for posterior cervical spine fixation and stability on various surgical indications. Cervical pedicle screw placement is technically demanding procedure because cervical pedicles are small in size and this has potential risk. A laminectomy is present bilaterally through much of the cervical spine. Backgroundcervical lateral mass screw fixation is indicated for the treatment of cervical subaxial c3c7 lesions associated with instability. Posterior cervical stabilization with lateral mass screws limits arthrodesis to the pathologic segments and allows for a rigid posterior construct that in turn enables early mobilization 5, 6. Key words spinal fusion cervical spine lateral mass neurosurg. C1 lateral mass anatomy proper placement of lateral mass.
There are several techniques for screw placement in the subaxial cervical spine. It is always interesting to learn screw placement in sub axial cervical spine by observing a video clip. How to read a mri of the normal cervical spine neck. The critical technical aspect of posterior cervical plating is the safe placement of screws into the lateral mass with a screw length sufficient for maximal fixation. The second part of the investigation employed a human cadaver model to assess the accuracy of pedicle screw placement in the cervical spine using three surgical techniques. Placement of cervical lateral mass screws constitutes an offlabel use although this is standard surgical practice. Laminaguided lateral mass screw placement in the subaxial. This allows for lateral mass screw fixation in the cervical spine and standard pedicle screw or hook fixation in the thoracic spine using a single rod.
Thus, we only use fluoroscopy at the start of the surgery to insure proper alignment of the cervical spine and for localization of the levels for screw placement. Implications for screw insertion into the first cervical lateral mass by jason p. Lateral mass screwrod fixation of the cervical spine. Posterior cervical fixation using a new polyaxial screw and. Based on this analysis, guidelines for pedicle screw placement relative to posterior cervical topography could be derived. Lateral mass screw fixation is a safe and effective. Abstract placement of pedicle screws in the cervical spine. Postoperative mri scanning confirmed the satisfactory screw placement in all the cases. Four lateral mass screw fixation techniques in lower cervical spine. No significant correlations for either screw type were found between pullout strength and bone density, screw length, or vertebral level. Toploading polyaxial screws with friction heads enable quick and simple construct assembly selftapping flute centers screw for easy.
Neurovascular injury resulting from lateral mass screw placement. Abstract study design a prospective study evaluating screw position and associated complications in 21 consecutive patients treated with a plate and screw fixation system applied to the lateral masses of the cervical spine. Aberrant posterior inferior cerebellar artery injury with c1 lateral mass screw placement. Although these systems are safe and reliable, they can be difficult to. This study aimed to introduce a novel strategy for safe and accurate insertion of lateral mass screw in the subaxial cervical spine. Paravertebral foramen screw fixation for posterior. Daniel riew, md investigation performed at the cervical spine service, department of orthopaedic surgery.
This type of placement, although technically difficult, may be an alternative to lateral mass screws in cases with unusual anatomy, stripped screws, or when additional intermediate points of fixation are desired. Posterior plating utilizing lateral mass screw fixation has been widely accepted for treating the unstable cervical spine caused by trauma, neoplasms, significant. For lateral mass screw placement, a modified magerl screw placement technique is used. Precision and safety of multilevel cervical transpedicular. The ideal screw entry point, direction, size and exit. The limitation of lateral mass screws as compared to pedicle. The use of c1 lateral mass screws in complex cervical. Minimally invasive lateral mass screws in the treatment of. A posterior cervical fusion with lateral mass screws cervical spine and pedicle screws thoracic spine and rods extends from c4 to t2. The authors first describe the surgical anatomy of the subaxial cervical posterior approach. Pdf background lateral mass screw fixation lsf techniques have been widely used for reconstructing and stabilizing the cervical spine.
Screw placement the thickest part of the cranium is the dense ridge which runs vertically in line with the internal occipital crest. Despite ubiquitous usage, surgeon education regarding the application of lumbar mass screw. In the cervical spine, neither lateral mass or pedicle screw techniques are federal drug administration fda approved in the united states. Lateral mass screw fixation lsf techniques have been widely used for reconstructing and stabilizing the cervical spine. Twenty freshfrozen disarticulated human vertebrae c3c7 were randomized to receive both a 3. Cervical pedicle screw placement in sawbone models and traumatic lesions formed. Mar 31, 2020 surgeons employing this technique require an understanding of the cervical anatomy, screw placement methods, and clinical indications. C7 intralaminar screw placement, an alternative to lateral. Use of spinous processes to determine the laterally angulated. Jun 19, 2011 cervical lateral mass screw fixation is indicated for the treatment of cervical subaxial c3c7 lesions associated with instability. Posterior lateral mass plate fixation of the cervical. There is an unrelated posterior spinal fusion psf at c3t2 with lateral mass screws at c36 and pedicle screws at t12.
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