Developmental anomalies of the lateral portion of the cervical neural arch: Multimodal imaging and clinical implications.

OBJECTIVE: This study aimed to describe the imaging spectrum of developmental anomalies of the lateral portion of the cervical neural arch. METHOD: This was a five-year retrospective review of consecutive computed tomography (CT) scans of the cervical spine for structural anomalies of the cervical vertebral pedicle and facets. CT, radiographs and, when available, magnetic resonance imaging studies were independently reviewed. Anomalies were grouped into the following three categories: the absence of a pedicle, clefts in the vertebral arch or isolated dysmorphism of the facet. Clinical data on demographics and neurological outcomes were documented. RESULTS: Among 9134 consecutive patients undergoing a CT scan of the cervical spine, 18 (0.2%) patients were found to have developmental anomalies of the pedicle and facets. Findings included 7/18 (39%) with congenital absence of a pedicle, 8/18 (44%) with clefts in the vertebral arch and 3/18 (17%) with isolated dysmorphism of the articular facets. No acute neurological deficits or spinal cord injuries were reported. Associated chronic symptoms included neck pain 10/18 (56%), radiculopathy 7/18 (39%) and myelopathy 1/18 (6%). CONCLUSION: Developmental anomalies of the pedicle and facet may mimic traumatic spinal pathologies. Recognising a diverse spectrum of imaging findings is vital to prevent misdiagnosis and unnecessary intervention.

Bilateral Accessory C1 and C2 Facet Joints; Clinical, Neuroradiological and Peroperative Findings in an Adult with Quadriparesis

Objectives Accessory C1 and C2 facet joints are very rare. Only few cases were reported in the literature.We report a case of bilateral accessory facets in an adult with special attention to clinical, neuroradiological, as well as peroperative findings. Case report A 37-year-old male presented with progressive quadriparesis. Radiology revealed bilateral posterior accessory C1 and C2 facet joints compressing the spinal cord with craniovertebral junction (CVJ) instability. Both accessory C1 and C2 facets with the posterior arch of the C1 were removed. Lateral mass screws and plates fixation at the C1 and C2 level, as well as fusion, were performed. Postoperatively, the patient recovered well. Conclusion In accessory C1 and C2 facet joints, when symptomatic, neuroradiological findings can guide to the proper diagnosis, to pathological understanding, and, ultimately, to management strategy.

Simultaneous odontoid excision with bilateral posterior C1-2 distraction and stabilization utilizing bilateral posterolateral corridors and a single posterior midline incision.

A simultaneous odontoid decompression and bilateral posterior atlanto-axial facetal distraction, C1-2 joint spacer/bone graft placement and stabilization may be performed utilizing the 'posterior-only' approach. This procedure may be performed utilizing a single posterior midline incision, a bilateral posterior approach to the C1-2 facet joints and a bilateral posterolateral approach to the odontoid process and C2 body. It may be carried out in situations where a C1-2 non-reduction/partial reduction using a 'posterior alone' procedure is anticipated due to the complex bony/soft tissue configuration anterior at the thecal sac existing at the cervicomedullary junction. In the four cases described in this report, the procedure led to a successful circumferential decompression at the level of foramen magnum along with posterior C1-2 facetal distraction and stabilization in various complex craniovertebral junction anomalies (atlantoaxial dislocation [AAD] and/or a high basilar invagination [BI] associated with a significantly retroverted dens, along with a rotatory component, due to grossly asymmetrical facet joints). This technique may also be utilized in those diseases that result in an anterior osteoligamentous mass at the CVJ associated with C1-2 instability.

Técnicas percutáneas con ozono en el quiste facetario lumbar: serie de casos / Percutaneous treatment with ozone for the treatment of the lumbar facet joint cyst: a case series

Los quistes sinoviales de las articulaciones facetarias lumbares son intraespinales, pero extradurales. Estos quistes extradurales pueden localizarse en el ligamento intraespinoso, la articulación facetaria, el ligamento amarillo o el ligamento longitudinal anterior. Aparecen más comúnmente en la cuarta o quinta décadas de la vida y son más frecuentes en la mujer que en el hombre. Se han publicado muchas alternativas de tratamiento contra los quistes facetarios, incluidos el seguimiento, la inyección de esteroides, la aspiración percutánea del quiste, la hemilaminectomía o laminectomía bilateral con o sin fijación y la incisión mínimamente invasiva. El objetivo de este trabajo fue describir la evolución clínica y anestesiológica de una serie de pacientes con quistes facetarios, quienes recibieron tratamiento médico con ozono, sin necesidad de intervención quirúrgica. Se presentó la evolución clínica de dos pacientes a los que se les aspiró sus respectivos quistes facetarios y se les inyectó ozono. Una de ellos recidivó y se le aplicó igual tratamiento, cuya evolución ha sido satisfactoria hasta el momento. La aspiración percutánea de los quistes facetarios es un procedimiento eficaz y de mínima invasión, evita la intervención quirúrgica en la columna y la evolución es satisfactoria(AU)

Synovial cysts of the lumbar facet joints are intraspinal, but extradural. These extradural cysts can be located in the intraspinal ligament, the facet joint, the yellow ligament or the anterior longitudinal ligament. They occur more commonly in the fourth or fifth decades of life and are more frequent in women than they are in men. Many treatment alternatives for facet joint cysts have been published, including follow-up, steroid injection, percutaneous cyst aspiration, bilateral hemilaminectomy or laminectomy with or without fixation, and minimally invasive incision. The aim of this study was to describe the clinical and anesthesiological evolution of a series of patients with facet joint cysts, who received medical treatment with ozone, without the need for surgical intervention. The clinical evolution was presented of the two patients who were aspirated their respective facet joint cysts and injected with ozone. One of them relapsed and was given the same treatment, and whose evolution has been satisfactory so far. Percutaneous aspiration of facet joint cysts, an efficient and minimally invasive procedure, avoids surgical intervention in the spine and its evolution is satisfactory(AU)

Lumbar Facet Tropism: A Comprehensive Review.

BACKGROUND: Scattered reports exist in the medical literature regarding facet tropism. However, this finding has had mixed conclusions regarding its origin and impact on the normal spine. METHODS: We performed a literature review of the anatomy, embryology, biomechanics, and pathology related to lumbar facet tropism. RESULTS: Facet tropism is most commonly found at L4-L5 vertebral segments and there is some evidence that this condition may lead to facet degenerative spondylolisthesis, intervertebral disc disease, and other degenerative conditions. CONCLUSION: Long-term analyses of patients are necessary to elucidate relationships between associated findings and facet tropism. In addition, a universally agreed definition that is more precise should be developed for future investigative studies.

Are Locked Facets a Contraindication for Extreme Lateral Interbody Fusion?

BACKGROUND: Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive treatment allowing for indirect decompression of neural elements. However, evidence regarding the influence of facet degeneration (FD) and facet tropism (FT) toward indirect decompression is lacking. The aim of the study was to evaluate whether indirect decompression is impaired by FD and FT in patients undergoing ELIF. METHODS: Thirty-seven patients undergoing ELIF were included in a retrospective study. Radiographic parameters including disk height, segmental disk angle, foraminal area, FD, FT, and clinical outcome parameters (Oswestry Disability Index and Visual Analog Scale) were measured preoperatively and postoperatively. FD and FT were correlated with radiographic and clinical outcome parameters in order to determine predictors restricting indirect decompression. RESULTS: Thirty-seven patients with a total of 74 levels were analyzed. Clinical and radiographic outcome measures including central canal area (Δ = +17.2 mm2), mean disk height (Δ = +3 mm), and foraminal area (Δ = +9.9 mm2) revealed significant improvement compared with before surgery (P ≤ 0.05). Patients with severe FD (grade 4) were more likely to have FT ≥ 12 degrees (32.3%) than patients without/mild (grades 0 and 1; 10%) or moderate FD (grades 2 and 3; 13%), P ≤ 0.05. FD and FT did not affect disk height restoration, foraminal area, canal surface area, or clinical outcome measures (P ≥ 0.05). CONCLUSIONS: Indirect decompression of neural elements in ELIF is not impaired by FD and FT are not relative contraindications in patients undergoing ELIF.

Irregular Alteration of Facet Orientation in Lumbar Segments: Possible Role in Pathology of Lumbar Disc Herniation in Adolescents.

BACKGROUND: The role of the overall structural feature of facet joint in the development of lumbar disc herniation (LDH) is unclear. The present study aimed to investigate the role of irregular alteration of facet orientation (IAFO) in low lumbar segments in the pathology of LDH in adolescents. METHODS: Sixty-five adolescents with LDH were included in the study. Facet angles were measured in magnetic resonance imaging. The IAFO was defined as the irregular orientation of the included facet joints angle, which was regularly increased from L3 to S1 in the normal group, including small-large-small (SLS) type, large-small-large (LSL) type, and large-small-smaller (LSS) type. Thirty normal adolescents without lumbar lesions were selected into the control group. Statistical analysis was performed using χ(2) test. RESULTS: IAFO was observed in 20 of 65 subjects in LDH group compared with 3 of 30 in the control group [P = 0.038; OR=4 (1.086, 14.735)]. The SLS type was observed in 14 patients, and the LSL type was found in 6 patients, compared with 2 and 1, respectively, in the control group, no LSS type was found in the two groups. There were 8 subjects with IAFO of SLS style herniated in L5/S1 level compared with 6 subjects in L4/5. There was 1subject with IAFO of LSL style herniated in L5/S1 level compared with 5 subjects in L4/5. CONCLUSIONS: The findings of this study suggest that the IAFO in the lumbar spine was associated with lumbar disc herniation in adolescents.

'Pseudofacets' or 'supernumerary facets' in congenital atlanto-axial dislocation: boon or bane?

PURPOSE: Certain abnormal contact points, appearing like additional joints (pseudofacets) were observed between atlas and axis in a subset of patients with congenital atlantoaxial dislocation (CAAD). The origin, function and bearing on management of such pseudofacets remain largely undetermined. The object is to study 'pseudofacets'or 'accessory joints' in patients with CAAD and to analyze the possible genesis, role and bearing of these on surgery and fusion rates. MATERIALS AND METHODS: 35 patients with CAAD were analyzed. Reconstructed images of CT craniovertebral junction passing through these pseudo and true facets were studied. A novel method was devised to measure the faceto-isthmic angle of axis, both in patients with CAAD and normal subjects. Operative details and fusion rates were studied in patients with pseudofacets and compared with those without it. RESULTS: Eight out of 35 patients (6 Irreducible CAAD and 2 with RCAAD) had pseudofacets. These are seen posterior to the true facets and resemble partially formed joints. The C2 facet was acutely bent over its isthmus in these patients. The direction of these pseudofacets appeared to counter the abnormal mobility at C1-2 true facets. Intraoperatively, they posed a visual hindrance to reach up to true facets for placement of spacers and lateral mass screws, requiring extensive drilling. At the same time, they did help in distraction and increased the surface for fusion between C1 and C2 in cases where sublaminar wiring alone was used. Fusion rates were 100 % in patients with pseudofacets. CONCLUSIONS: Pseudofacets may be a result of genetic aberration and nature's mechanism to restrict abnormal C1-2 mobility in CAAD by imparting some stability. Their presence hinders the visualization making it difficult to reach upto the true facets, thus a bane. They may require extensive drilling when direct posterior approach is used, thereby disrupting the natural restrictive mechanism. However, the flattened surfaces provide an increased area for postoperative bony fusion between C1 and 2, making their presence a 'boon'.

Congenital absence of the lumbar facet joint associated with bilateral spondylolysis of the fifth lumbar vertebra.

A 14-year-old boy presented with a rare case of congenital absence of lumbar facet joint manifesting as low back pain. Physical examination showed no neurological or hematologic abnormalities. Radiography revealed absence of a facet joint on the right side of L4-5. Computed tomography and three-dimensional computed tomography revealed absence of the facet joint on the right side of L4-5 and spondylolysis on both sides of L5. Pain subsided after conservative treatment. This is an extremely rare case of congenital absence of lumbar facet joint associated with bilateral spondylolysis.

Ossicles of lumbar articular facets: normal variant or spondylolytic variant?

PURPOSE: The objective of this study was to establish the prevalence and significance of ossicles of lumbar articular facets (OLAF) in young athletes with backache diagnosed by multi-detector computed tomography (MDCT). MATERIALS AND METHODS: The MDCT examinations of the lumbar spine carried out for suspected spondylolysis on 46 consecutive symptomatic young athletes presenting to a sports injury clinic over a 1-year period were retrospectively reviewed. OLAF study included detailed correlation with the structural and morphological stress features of the posterior neural arches. This was then compared with a control group composed of 39 patients. RESULTS: Twenty-three OLAF were identified in 15 patients. Eleven of the 15 patients with ossicles had posterior element stress changes (PEST)/pars defects. In the control group, two OLAF were identified in two patients, one demonstrating PEST changes. CONCLUSION: The high prevalence of OLAF in young symptomatic athletes compared with the asymptomatic control group is indicative of stress fractures. The non-united articular process fractures should be regarded as part of the spectrum of stress-induced changes in the posterior neural arch in the same way as spondylolysis. MDCT with volumetric acquisition and multi-planar reformation is the most reliable investigation in the diagnosis of OLAF. KEY POINTS: 1) This CT study supports a traumatic aetiology for lumbar articular facets ossicles. 2) OLAF represent part of a spectrum of stress-induced changes in the posterior neural arch. 3) OLAF are associated with typical spondylolysis. 4) OLAF can be overlooked on reverse gantry angle computed tomography (RG-CT). 5) OLAF may account for some of the discrepancy between radionuclide and RG-CT studies.

Fusionless posterior hemivertebra resection in a 2-year-old child with 16 years follow-up.

PURPOSE: We present the case of a 2-year-old patient with congenital scoliosis due to a lumbar hemivertebra. The current gold standard treatment of such an abnormality would be hemivertebra resection and short level posterior spinal fusion. However, due to the young age of the patient, we considered that application of a fusionless solution might offer advantages in terms of retaining normal segmental motion and the potential for growth. METHODS: The incarcerated hemivertebra was resected and the facet joints of the neighbouring vertebrae were joined to create a new functional motion segment and correct the kyphoscoliotic deformity. Transpedicular screws were inserted on the convex side in L2 and L3 and a tension band was applied. RESULTS: 16 years after the surgery, the patient was completely pain-free, motion of the lumbar spine was preserved and the physiological curvatures were maintained. CONCLUSION: To our knowledge a fusionless surgical solution for the treatment of a hemivertebra has never been described before. Although this is only a single case, the good result with a long follow-up suggests the technique is worthwhile considering when planning the treatment of a lumbar hemivertebra in very young children.

Existence of two separate facet joints on the same side: case of a congenital anomaly.

We present a case that had two separate facet joints on the same side causing an intervertebral instability. The embryological pathogenesis of the congenital existence of two separate facet joints on the same side of the vertebra is not conclusively known. A 68-year-old woman presented with lower back pain and severe left leg pain. Neuroradiological evaluation including dynamic plain radiography, computed tomography, and magnetic resonance imaging of the lumbar spine revealed the existence of two separate facet joints on the same side of the first sacral vertebra, severe degenerative changes of both right and left L5-S1 facet joints, and Grade II L5-S1 spondylolisthesis. Subsequently, she underwent surgery. Intraoperatively, two separate facet joints on the same side of the first sacral vertebra were confirmed. The patient's symptoms were resolved after decompression and fusion surgery. This is a unique case of the congenital existence of two separate facet joints on the same side of the first sacral vertebra.

Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report.

We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent in the region innervated by L5 and S1 nerve roots. Preoperative multidetector three-dimensional computed tomography (3D-CT) showed complete absence of the right S1 superior articular process. Magnetic resonance (MR) images showed lumbar disc herniation at right L5-S1 level that migrated cranially. Intraoperative findings revealed that the right L5 nerve root and S1 nerve root were conjoined, and the conjoined nerve root was compressed by L5-S1 disc herniation, which led to impairment of the conjoined nerve root by a single-level lumbar disc herniation. After removal of the disc herniation, his right leg pain immediately subsided, however muscle weakness and sensory disturbance persisted. Surgeons should be aware of this nerve root anomaly when examining a patient who shows an unusual clinical presentation and/or congenital osseous anomaly.

Cervical myelopathy accompanied with hypoplasia of the posterior arch of the atlas: case report.

STUDY DESIGN: Case reports of 2 patients having cervical myelopathy accompanied with idiopathic hypoplasia of the posterior arch of the atlas. OBJECTIVE: A standard for the sagittal inside diameter (SID) of the vertebral foramen of the atlas was determined for use in the diagnosis of hypoplasia. From the point of view of short SID, the etiologies of myelopathy in patients with this disease were analyzed. SUMMARY OF BACKGROUND DATA: There is no established definition of hypoplasia of the atlantal vertebral foramen. The mechanism underlying the occurrence of this myelopathy in adulthood is unknown. METHODS: Lateral x-ray views of the cervical vertebrae of 150 Japanese men and 150 Japanese women were investigated, and the standard values of the SID were obtained. The features of myelopathy associated with this disease were analyzed in 2 cases managed at our facility and in the literature. RESULTS: The mean standard value was 34.4 mm in women and 37.1 mm in men, showing a significant sex difference (P<0.0001). When a case with a value -2 SD below the standard was regarded as having hypoplasia, case 1 (female) showed 25 mm, that is, -3.9 SD, and case 2 (male) showed 30 mm, that is, -2.7 SD. The space available for the spinal cord of the atlas was 8.0 mm in case 1 and 9.5 mm in case 2. Both patients showed atlantoaxial subluxation on images, but atlantodental interval on flexion in cases 1 and 2 was 3.8 and 4.5 mm, respectively, showing the degree to be mild. CONCLUSIONS: In the presence of congenital hypoplasia of the posterior arch of the atlas, the spinal cord is highly susceptible to injury because congenital spinal canal stenosis is present. Therefore, the presence of even a mild mechanical compressive lesion leads to myelopathy. Acquired mild atlantoaxial subluxation was associated with this hypoplasia, and the association was considered to be the mechanism underlying the occurrence of myelopathy in adulthood.

Treatment of pediatric atlantoaxial instability with traditional and modified Goel-Harms fusion constructs.

There are several treatment options for rigid fixation at C1-C2 including Brooks and Gallie type wired fusions and C1-2 transarticular screws. The use of a Goel-Harms type fusion, a construct with C1 lateral mass screws and C2 pedicle screws, has not been extensively described in pediatric patients. Here, we describe its relatively safe and effective use for treating pediatric patients by retrospective chart review of patients treated by the senior author for atlantoaxial instability with a Goel-Harms-type constructs during a 3-year period (2005-2007). Six patients were treated using Goel-Harms-type constructs. Five patients were treated utilizing a construct containing C1 lateral mass screws and C2 pedicle screws; one patient was treated using construct containing C1 lateral mass screws and C2 trans-laminar screws. The patients ranged in age from 7 to 17 years old (mean 12.7). All patients had findings of an os odontoideum on CT scans and three of the six patients had T2 hyperintensity on MRI. Three of the six patients presented with transient neurologic deficits: quadraplegia in two patients and paresthesias in two patients. In each patient C1 lateral mass and C2 screws were placed and the subluxation was reduced to attain an anatomical alignment. No bone grafts were harvested from the iliac crest or rib. Local morsalized bone and sub-occipital skull graft was used. All patients tolerated the procedure well and were discharged home on post-operative day 3-4. The patients wore a hard cervical collar and no halo-vests were needed. All patients had solid fusion constructs and normal alignment on post-operative imaging studies performed on average 14 months post-operatively (range: 7-29). The results demonstrated that Goel-Harms fusions are a relatively safe and effective method of treating pediatric patients with atlantoaxial instability and are not dependent on vertebral anatomy or an intact ring of C1. Follow-up visits and studies in this limited series of patients demonstrated solid fusion constructs and anatomical alignment in all patients treated.

Spontaneous rotatory atlantoaxial dislocation without neurological compromise in a child with Down syndrome: a case report.

Spontaneous atlantoaxial dislocation is a rare recognised complication of Down syndrome. In the majority of cases, dislocation takes place in an anteroposterior direction and is often associated with abnormalities of odontoid development or ossification. Rotatory atlantoaxial dislocation is extremely rare in Down syndrome and this is to our knowledge the first reported case in which modern imaging methods have been described; surface shaded reformats derived from a multislice CT scan were of fundamental importance in making the diagnosis.

Congenital absence of a lumbar pedicle presenting with contralateral lumbar radiculopathy.

The authors describe a rare case of a congenital absence of the right L5 pedicle in a 54-year-old man presenting with low back pain and radicular pain of his left leg. Plain x-ray films, computed tomography scan (CT) after myelography, and three-dimensional CT revealed the absence of the L5 pedicle and anomaly of the L4-L5 facet joint on his right side. On the left side, there were severe degenerative changes that were thought to be the result of an overload and instability. The degenerative changes led to late-onset neurologic impairment of the contralateral side, which was treated with spinal fusion. To our knowledge, this is the first report of contralateral symptoms due to unilateral defect of the facet joint accompanied by aplasia of a pedicle.