Lateral Mass Plate Research Articles

Os Odontoideum: Analysis of 190 Surgically Treated Cases

The aim of this study was to report an experience with 190 cases of os odontoideum over 20 years. The management outcome following atlantoaxial fixation was analyzed. From January 2000 to September 2018, 190 patients with os odontoideum were surgically treated. There were 113 male patients and 77 female patients; average age was 24 years (range, 2-68 years).The patients were divided into 3 groups depending on the nature of atlantoaxial dislocation (group 1, mobile and partially or completely reducible atlantoaxial dislocation; group 2, fixed or irreducible atlantoaxial dislocation; group 3, presence of basilar invagination). There were 65 pediatric patients (<18 years old). All patients underwent atlantoaxial joint manipulation and lateral mass plate and screw fixation. The goal of surgery was segmental atlantoaxial arthrodesis. No transoral or posterior foramen magnum bone decompression was done. Occipital bone was not included in the fixation construct. On direct bone handling and observation, atlantoaxial joint pathologic hyperactivity related instability was identified in all patients. Atlantoaxial segmental stabilization resulted in clinical symptomatic and neurologic improvement in 100% of patients. Os odontoideum signifies chronic or long-standing atlantoaxial instability. Segmental atlantoaxial fixation is a reliable form of surgical treatment. Bone decompression is not necessary. Inclusion of occipital bone and subaxial vertebrae in the fixation construct is not necessary.

Pedicle screw fixation in the lower cervical spine: Case series

Background: Pedicle screw fixation of lower cervical spine is a new technique that provides an alternative to posterior lateral mass plating. Although biomechanical studies suggest the use of pedicle screws to reconstruct the cervical spine, placing screw in small cervical pedicle poses a technical challenge. Penetreation of screw in pedicle is a primary complication associated with screw insertion in the lower cervical spine. Aim and Objective: To manage the cervical spine injuries by pedicle screw presented to department of Orthopaedics, BPKIHS, Dharan. Materials and methods: This is retrospective interventional study done at the department of Orthopaedics, B.P. Koirala Institute of Health Sciences, Dharan, Nepal over a period of 2 years from March 2012 to April 20014. A total of 55 patients with cervical spine injuries were treated by pedicle screw. The patient’s age ranged from 20 to 60 years and the mean follow-up was 12 weeks. Results: The study comprised of 55 patients with cervical spine injuries were treated by pedicle screw The age incidence in this series ranged from 20 years to 60 years. 40 patients were males and 20 was female. All had fractures or fracture dislocation at different levels of lower cervical spine. The mechanism of injury included falls from height (80%), motor vehicle accidents (18%) and sports related injury (2%). Discussion: Pedicle screw insertion into the pedicles in the lower cervical spine is technique that requires a solid knowledge of 3-dimensional anatomy of cervical spine and experience of pedicle screw fixation in thoracolumbar spine. The biomechanical advantages of pedicle screw fixation in cervical spine is obvious, but data are limited. However, safety and role of pedicle screw fixation in reconstruction in the lower cervical spine have not been defined. Conclusion: It is indicated in patients with osteoporotic bone or when rigid internal fixation can not be achieved by conventional techniques.

Surgical Treatment Outcomes in Metastatic Tumours Located at the Craniocervical Junction.

Cancer metastases to the upper section of the cervical spine are found in a low percentage of patients. Their conservative treatment consists in radio- and chemotherapy as well as immobilisation in an orthopaedic collar. Surgery is the treatment of choice in patients with lesions causing spinal instability or compressing neural structures. The aim of this study was to assess the outcomes of surgical treatment conducted in patients with metastases located in the upper section of the cervical spine. The study analysed the medical records of 20 patients who underwent surgical treatment at the Department of Oncological Orthopaedics in Brzozów in 2015-2016. The majority of the patients were female (75%). The mean age of the male patients was 58 years and that of the female patients was 68 years. The most common complaints were pain (90%) and neurological deficits (50%; mainly Frankel Grade C). The most common primary tumour was breast cancer (35%). 58% of the patients had slow-growing tumours according to the Tomita system. Surgical procedures lasted a mean of 117 minutes and involved fixation of a mean of 7.5 levels. The treatment reduced the patients' VAS score for pain by 3.89 points, improved function (Karnofsky scale) by 18 points and produced neurological improvement in 66% of the patients. The overall 2.5-year survival rate was 35%. The mean hospital stay lasted 14.5 days. One patient died on the 8th post-operative day due to cardiovascular complications. There was one case of delayed wound healing due to a haema-toma. No mechanical damage to the implants, infections, or cerebrospinal fluid leaks were found. 1. Metastases located in the upper cervical spine are rare and cause significant technical difficulties. 2. Fixation with lateral mass screws and plates fixed with screws to the occipital bone is a safe and effective method. 3. Surgical treatment allows for restoring spinal stability, reducing pain, and improving the patients' quality of life.

Anterior Fixation of Atlantoaxial Joints: Technique and Pitfalls

Both the atlantoaxial joints can be exposed adequately by an unilateral extrapharyngeal approach from the right side. The atlantoaxial dislocation can be reduced, joints can be decorticated and bone graft can be introduced into the joint. The odontoid process can be drilled and removed. The C1-C2 joint can be fixed either by (1) C1 lateral mass and C2 body screw plate bilaterally, or (2) bilateral anterior C2-C1 transarticular screws.

Spinous process plate fixation for cervical spinal fusion after spinal trauma: two case reports

Spinous process plate fixation for cervical spinal fusion after spinal trauma: two case reports

Alternative technique of cervical spinal stabilization employing lateral mass plate and screw and intra-articular spacer fixation.

Aim:The author discusses an alternative technique of segmental cervical spinal fixation.Material and Methods:The subtleties of the technique are discussed on the basis of experience with 3 cases with a follow-up of between 30 and 36 months.Technique:The technique involves debridement of facetal articular cartilage, distraction of facets, jamming of ‘Goel spacer’ into the articular cavity and fortification of the fixation by lateral mass plate and screw fixation. The ‘double-insurance’ method of fixation is safe for vertebral artery, nerve roots and spinal neural structures and the fixation is strong.Conclusions:The discussed technique is safe and provides a strong fixation and a ground for ultimate arthrodesis.

Posterior open-door laminoplasty combined with lateral mass plate fixation in the treatment of ossification of the posterior longitudinal ligament of the cervical spine

To evaluate the clinical effect of posterior decompression and open-door laminoplasty combined with lateral mass plate fixation in the treatment of ossification of the posterior longitudinal ligament of the cervical spine (OPLL). A total of 41 OPLL patients in our hospital, with differing extents of spinal compression, were analyzed retrospectively. All cases underwent a posterior open-door laminoplasty operation, and lateral mass plate fixation. The Japanese Orthopedic Association ( JOA) score was adopted to evaluate nerve function. All cases were followed up for 12 to 16 (14±2.0) months. The postoperative JOA score was increased 4.8 points compared with the preoperative. Posterior open-door laminoplasty combined with lateral mass plate fixation for ossification of the posterior longitudinal ligament of the cervical spine possesses the advantages of extensive applicability, simplicity and safety, and strong stability. It is an efficient and reliable method for ossification of the posterior longitudinal ligament.

Expert's comment concerning Grand Rounds case entitled "Temporary occipito-cervical stabilization of an unilateral occipital condyle fracture" (by Klaus John Schnake, Andreas Pingel, Matti Scholz and Frank Kandziora).

Expert's comment concerning Grand Rounds case entitled "Temporary occipito-cervical stabilization of an unilateral occipital condyle fracture" (by Klaus John Schnake, Andreas Pingel, Matti Scholz and Frank Kandziora).

Fracture-séparation du massif articulaire droit de la troisième vertèbre cervicale traitée par vissage des masses latérales

Facet joint dislocations of the cervical spine are distractive-flexion injuries that account for 6 to 10 % of traumatic lesions of the subaxial cervical spine. Distractive-flexion injuries of the cervical spine were classified into four stages by Allen and Fergusson. These unstable lesions predominate at the fifth and sixth levels and all aspects of their management are subject to controversy, including their classification. Attempting reduction before surgery, performing MRI before or after closed reduction, choosing between surgery and external contention, the anterior versus the posterior approach are still matters of controversy between experts. The authors report a stage 2 distractive-flexion injury of the right facet joint of the third cervical vertebra treated by lateral mass plating as described by Roy-Camille (1995).

Craniovertebral instability due to degenerative osteoarthritis of the atlantoaxial joints: analysis of the management of 108 cases

The authors retrospectively analyzed a series of 108 patients in whom was diagnosed atlantoaxial instability due to degenerative osteoarthritis of the atlantoaxial joints. The management issues in such cases are discussed. One hundred eight patients with osteoarthritis of the atlantoaxial joints and resultant craniovertebral instability-diagnosed on the basis of presenting clinical features, radiological imaging, and direct observation of the joint status during surgery-were retrospectively analyzed. Between 1990 and 2008, these patients were treated with a C1-2 lateral mass plate and screw method of atlantoaxial fixation and joint distraction using bone graft with or without the assistance of metal spacers. Patient ages ranged from 48 to 84 years (average 63 years). There was a history of mild to moderate head and/or neck trauma 2 months to 11 years prior to diagnosis in 40% of the cases. All patients had symptoms of neck pain, and 82% of the patients had progressive myelopathy. A reduction in the height of the atlantoaxial lateral mass complex (100%), mobile atlantoaxial dislocation (100%), basilar invagination (68%), and periodontoid degenerative tissue mass (90%) were the more frequently encountered radiological features. Two patients died in the immediate postoperative period. At an average follow-up of 64 months, all surviving patients remarkably improved to varying degrees in their neurological condition. Atlantoaxial joint arthritis frequently leads to craniovertebral instability and cord compression. Treatment by joint distraction and lateral mass fixation can be an optimum form of treatment.

Lateral atlantoaxial facetal dislocation in craniovertebral region tuberculosis: report of a case and analysis of an alternative treatment

A case of tuberculosis is reported in which there was extensive unilateral destruction of the bones of the craniovertebral junction. A lateral facetal subluxation of the relatively well-preserved contralateral atlantoaxial joint was identified. The patient was treated with unilateral fixation of the subluxated joint using a lateral mass plate and screw method of fixation. The pathogenesis of facetal subluxation and the rationale of the treatment adopted are discussed. A 63-year-old male patient had systemic tuberculosis and had been on drug treatment for 5 months. For about 1 month, he had experienced severe neck pain and progressive quadriparesis. Investigations revealed extensive unilateral destruction of the lateral masses of atlas and axis and occipital condyle. MRI showed altered cord signal at the level of the craniovertebral junction. CT scan showed contralateral lateral subluxation of the facet of atlas over the facet of axis. Unilateral fixation and distraction of the lateral mass of atlas and axis, external orthosis and antituberculous drug treatment resulted in rapid and sustained neurological recovery. Contralateral atlantoaxial facetal subluxation can be a result of osteoligamentous incompetence in cases of tuberculosis where there is unilateral facetal destruction. A coronal CT scan view can be diagnostic in such cases. Atlantoaxial lateral mass fixation can be a rational form of surgical treatment in such cases.

Posterior stabilization strategies following resection of cervicothoracic junction tumors: review of 90 consecutive cases

In this retrospective analysis the authors describe the assessment and outcomes of 90 patients who underwent placement of posterior instrumentation at the cervicothoracic junction following the resection of a primary or metastatic tumor during a 10-year period. All patients underwent a posterolateral laminectomy including uni- or bilateral facetectomy, and 44 patients additionally required vertebral body resection and reconstruction. In patients who underwent C-6 or C-7 decompression, the posterior instrumentation strategies changed from the use of lateral mass plate systems (LMPSs) to lateral mass screw/rod systems (LMSRSs). Similarly, for T1-3 tumor decompression, the strategy shifted from sublaminar hook/rod systems (SHRSs) to the use of pedicle screw systems (PSSs) in which the surgeon used either a 6.25-mm rod or dual-diameter rods with or without a connector. The overall surgical complication rate was 19% including fixation failure in 11 patients (12%), 6 of whom required reoperation. Fixation failure rates for cervical decompression decreased from 2 (29%) of 7 patients in the LMPS group to 0 (0%) of 8 in the LMSRS group (p = 0.2). The fixation failure rates for thoracic decompression were 7 (15%) of 48 patients in the SHRS group, and there was a decrease to 2 (7%) of 27 in the PSS group (p = 0.48). Neurological and functional outcomes including American Spinal Injury Association, Eastern Cooperative Oncology Group, and Medical Research Council muscle strength and pain scores remained stable or improved in 94, 96, 100, and 96% of patients, respectively. Current posterior instrumentation strategies involving LMSRSs and PSSs provide excellent and safe stabilization of the cervicothoracic junction following resection of primary or metastatic tumors.

Cervical Kyphosis and Thoracic Lordoscoliosis in a Patient With Cerebral Palsy

The management of cerebral palsy and spinal deformity can be challenging for spine surgeons. Scoliosis is the most common spinal deformity associated with cerebral palsy; however, the development of thoracic lordoscoliosis is rare. Cervical kyphosis in cerebral palsy patients is associated primarily with athetoid cerebral palsy. This article presents a case of progressive myelopathy and concurrent cervical kyphosis and thoracic lordoscoliosis in a 17-year-old spastic quadriplegic cerebral palsy patient who underwent 2-stage treatment. In the first stage, the cervical spine was managed with a 2-level cervical corpectomy of C5 and C6, with multilevel laminectomies, lateral mass plating, and wire fixation. In the second stage 3 months later, the thoracic deformity was corrected through a combined anterior spinal release of the thoracic spine with posterior spinal segmental instrumentation and sublaminar wiring. Postoperatively, the patient successfully returned to independent ambulation.

Vertical Atlantoaxial Index

An index for measuring the vertical relationship of atlas and axis is described. Deduction and application of vertical atlantoaxial index (VAAI) for quantifying the vertical atlantoaxial relationship of atlas and axis and classifying basilar invagination (BI) based on the VAAI. A number of craniospinal parameters have been described to quantify the amount of BI in relation to herniation of odontoid into the cranium. Successful treatment of BI by distraction of atlantoaxial facet joint, placement of a spacer to maintain the distraction, and lateral mass fixation has been described recently. The treatment is based on the understanding that BI is in fact a disease of the atlantoaxial facet joints and is a result of progressive vertical instability. With this new concept and technique that involves preserving all bony elements and reduction of BI in the form of reducing the vertical atlantoaxial subluxation, we thought it was prudent to formulate an index to quantify the relation of atlas and axis in the sagittal plane. Mid-sagittal computerized tomography (CT) scan films of 90 cases of BI treated by us between October 1999 and May 2005 with distraction and lateral mass plate and screw fixation were analyzed before and after surgery. The age of the patients ranged from 8 to 55 years and the male:female ratio was 2.5:1. Additionally, mid-sagittal CT scan films of hundred normal subjects in the same age group were analyzed as a control group. The VAAI was measured in all cases. VAAI is an index that measures the vertical relationship of the atlas and axis. The images were compiled and copies of the compilation were made. Two observers independently performed the measurements and intraobserver as well as interobserver agreement was assessed using the intraclass corelation (ICC) ) test (SigmaStat). The preoperative mean and mode values of VAAI in this series of patients were 0.53 (0.20 to 0.67) and 0.61, respectively. The postoperative mean and mode values of VAAI are 0.78 (range, 0.60 to 0.89) and 0.80, respectively. The mean and mode values of VAAI in general population were 0.80 (range, 0.76 to 0.85) and 0.80, respectively. The results in preoperative patients with BI demonstrated excellent intraobserver (ICC=0.96 and 0.98) and interobserver corelation coefficient (ICC=0.96). The results in normal subjects and postoperative CT scans of operated patients with BI also showed excellent intraobserver (ICC=0.97 and 0.98) and interobserver corelation coefficient (ICC=0.97). VAAI can be an excellent measurement tool for the assessment of relationship of atlas and axis. Nonrheumatoid BI can be graded and classified depending on the value of VAAI.

Circumferential fusion for sub-axial cervical spine fracture — subluxations

Fracture subluxation or traumatic spondylolisthesis of sub-axial cervical spine is a common but serious spinal injury encountered by neurosurgeons. It is frequently associated with spinal cord injury. Although decompression of spinal cord either anteriorly or posteriorly depending upon the site of compression is straight forward, there is no consensus regarding the approach for stabilization of spine either anterior or posterior or both, after decompression of spinal cord. Circumferential fusion involves combined anterior and posterior stabilization of sub-axial cervical spine. Some of the cases of circumferential fusion performed by the author are presented here. Anterior stabilization was performed with titanium cage or iliac graft insertion at corpectomy or discectomy site along with Anterior cervical plating and posterior stabilization was performed with Apofix clamps or interspinous wiring (cable) or lateral mass plating. Also one patient in whom only anterior stabilization was performed but who had recurrence of dislocation is also cited as an example of inadequacy of only one approach of stabilization to a 3 column cervical spine injury.

Single Level Arthrodesis as Treatment for Midcervical Fracture Subluxation

Although many different techniques exist for fusion of midcervical facet fracture dislocations, limiting arthrodesis to a single level could have a theoretical advantage: fewer fused segments could lessen long-term negative effects of fusion on adjacent segments. Therefore, we prospectively treated 22 consecutive patients with midcervical fracture dislocation without vertebral body fracture with single level arthrodesis even if anterior/posterior surgery were required. Twelve patients with unilateral facet subluxation underwent anterior cervical discectomy, distraction reduction with Caspar posts (AESCULAP, Tuttlingen, Germany) with allograft fusion and anterior cervical plating. Ten patients with any component of bilateral facet subluxation underwent anterior cervical discectomy, distraction reduction with Caspar posts, allograft fusion and plating followed by posterior lateral mass plating. No patients demonstrated worsening of nerve root or spinal cord function postoperatively. Interbody stability occurred in all cases. Only complications were 4 cases of pneumonia, 1 case of wound leakage, and 1 case of superficial wound infection. Good reduction was achieved for both unilateral and bilateral facet fractures. Single level interbody arthrodesis is safe and effective strategy with both unilateral and bilateral facet fractures. Single level arthrodesis may also offer long-term benefit compared with multilevel fusions.

Failure of reconstruction surgery using anterior fibular strut grafting to correct postlaminectomy kyphosis

A patient with postlaminectomy kyphosis with a neurological deficit which developed following the initial surgical treatment is reported. A 49-year-old man, complaining of neck pain, sought treatment in 1995. An extramedullary cervical spinal tumor was diagnosed and C2–C4 laminectomy and resection of the tumor were performed. Recurrence of the tumor was seen 1 year later and a second tumor resection and radiation therapy were performed. One year after the second resection of the tumor, X-rays of the cervical spine revealed kyphosis. Anterior spinal fusion without instrumentation was performed followed by immobilization using a halo vest for 4 months. However, pseudoarthrosis and progression of the kyphosis occurred postoperatively. Iliac bone grafting at the pseudoarthrosis site and posterior internal fixation with lateral mass plates was performed. Bony fusion between the graft and C6 vertebra was obtained after these procedures, but the neurological deficits were not completely resolved. Clinicians who treat spinal cord tumors may learn from this treatment failure.

One stage reduction and fixation for atlantoaxial spondyloptosis: report of four cases

We report four patients having an extremely rare and hitherto unreported clinical condition of spondyloptosis of the atlas over axis. Between the year 1999 and 2004, four patients with spondyloptosis were retrospectively analysed. The age of the patients ranged from 12 to 31 years. In three patients, the aetiology of spondyloptosis was probably congenital in nature and in one case it was secondary to rheumatoid disease. The patients presented with varying degrees of neck pain and spastic quadriparesis. All patients were successfully treated by atlantoaxial joint distraction, reduction of the dislocation and direct lateral mass plate and screw fixation by techniques described earlier by the senior author. Manipulation of the atlantoaxial joints and restoring the anatomical craniovertebral alignments is possible and probably an ideal treatment of cases with atlantoaxial spondyloptosis.

An Outcomes Analysis of the Treatment of Cervical Pseudarthrosis With Posterior Fusion

A retrospective review of 33 consecutive patients treated with posterior fusion and selective nerve root decompression for the treatment of pseudarthrosis following anterior cervical discectomy and fusion. Use standardized outcome measures to evaluate the results of posterior fusion with selective nerve root decompression as a treatment option for symptomatic pseudarthrosis of the cervical spine. Pseudarthrosis after anterior cervical discectomy and fusion has been recognized as a cause of continued cervical pain and unsatisfactory outcomes. Debate continues as to whether a revision anterior approach or a posterior fusion procedure is the best treatment for symptomatic cervical pseudarthrosis. To our knowledge, standardized outcome measures have not been used to evaluate the results of either surgical treatment option; therefore, it is difficult to evaluate outcomes in these patients, let alone compare surgical treatment options. Data on fusion rates in these two surgical treatment groups suggest a trend of a higher fusion rate with utilization of a posterior revision procedure, but the largest study to date includes the study of only 19 patients treated with a posterior fusion. Thirty-three consecutive patients with symptomatic pseudarthrosis following anterior cervical discectomy and fusion were treated with selective nerve root decompression and posterior fusion using iliac crest or local bone graft as well as posterior wiring and/or lateral mass plating. The average follow-up period was 46 months (range, 20-86 months). Patients were assessed using physical examination, flexion-extension lateral radiographs, and standardized outcome measures including the SF-36, Arthritis Impact Measurement Scales 2, and Cervical Spine Outcomes Questionnaire. All 33 patients (100%) demonstrated a solid fusion at their most recent follow-up, and all 33 patients noted significant improvement in their preoperative symptoms. No difference in fusion status was noted between those treated with iliac crest versus patients treated with local bone graft--all had a solid fusion; 72% of the patients were satisfied with the result of their surgery. Cervical Spine Outcomes Questionnaire pain scales demonstrated 52% of patients reported mild or nopain at follow-up, whereas 20% described their pain as "discomforting" and 28% of the patients continued to report moderate to severe pain. This is the first study to our knowledge to use standardized outcome measures to assess clinical outcome in patients treated with posterior fusion for pseudarthrosis after anterior cervical discectomy and fusion. Patients and surgeons need to understand the potential for success with this revision procedure but also be aware of the relatively high rate of continued moderate to severe pain observed in this patient population even after a solid fusion is achieved. All of the patients in this study fused with a single posterior fusion procedure, further supporting the relatively higher fusion rates observed in the literature using posterior fusion as a treatment for cervical pseudarthrosis. Our results also support the ability of surgeons to use local bone graft without iliac crest in a posterior fusion for cervical pseudarthrosis and therefore avoid the morbidity associated with iliac crest bone graft harvest.

Progressive Basilar Invagination After Transoral Odontoidectomy: Treatment by Atlantoaxial Facet Distraction and Craniovertebral Realignment

The issue of progression of congenital basilar invagination is evaluated on the basis of 3 clinical cases. The rationale of treatment of basilar invagination in general and, particularly, in the complex clinical situation encountered in the presented cases, by the authors' technique of atlantoaxial joint distraction, reduction of basilar invagination, and direct lateral mass plate and screw fixation is discussed. The subject of progression of congenital basilar invagination and recurrent craniocervical cord compression after an initial transoral decompression is analyzed, and an alternative surgical treatment involving craniovertebral bone realignment is suggested. This is a review of 3 cases of basilar invagination treated earlier by transoral decompression. No fixation procedure was performed. The patients presented with recurrent symptoms of high cervical cord compression. Investigations revealed a progression of basilar invagination and cord compression. The treatment of such a complex clinical situation by atlantoaxial joint distraction is discussed. Between September 2001 and January 2004, we treated 3 patients with congenital basilar invagination who underwent transoral odontoidectomy but did not undergo any posterior atlantoaxial or occipitoaxial fixation. The patients had postoperative improvement but worsening of their neurologic condition after an average duration of 26 months after transoral surgery. Repeat investigations revealed that basilar invagination and the craniovertebral alignments worsened during the period, and there was recurrent cervicomedullary cord compression. These patients were treated by atlantoaxial facet distraction, and attempts were made toward reduction of the basilar invagination and craniovertebral junction bony realignment, and atlantoaxial fixation by the technique recently described by us. During the average follow-up of 25 months, all 3 patients have had a neurologic recovery. The probable cause of basilar invagination and its progression is a congenital malformation ofalignment of the facets of the atlantoaxial joint. Distraction of the facets and direct interarticular atlantoaxial fixation presents a unique opportunity of reduction of the basilar invagination and fixation of the region.