scholarly journals Anatomical Parameters for Occipital Condyle Screws: An Analysis of 500 Condyles Using CT Scans

2021 ◽  
pp. 219256822098331
Author(s):  
David N. Bernstein ◽  
Tochukwu C. Ikpeze ◽  
Kenneth Foxx ◽  
Adan Omar ◽  
Addisu Mesfin
Keyword(s):  
Clinical Care ◽  
Ct Imaging ◽  
Occipital Condyle ◽  
Neoplastic Disease ◽  
Optimal Outcomes ◽  
Occipitocervical Fixation ◽  
Cervical Fractures ◽  
Length Width ◽  
Occipital Condyles ◽  
Anatomical Parameters

Study Design: Retrospective observational study. Objective: To establish occipital condyle dimensions (length, width, height), as well as the medialization angle necessary for safe occipital condyle screw placement in occipitocervical fixation. Methods: Between 1/2014-6/2014, patients who presented to a single level 1 academic trauma center emergency room and received computed tomography (CT) imaging of the cervical spine as part of routine clinical care were identified. After excluding patients with cervical fractures, neoplastic disease, or infection, 500 condyles representing 250 patients were analyzed. Condyle length, height, and width (all reported in millimeters [mm]) were evaluated on the sagittal, coronal, and axial series, respectively. Medialization angle (reported in degrees) was evaluated on the axial series of CT imaging. Measurements were compared by sex and age. Results: The average condyle length, width, and height were 18.6 millimeters (mm) (range, 14.5-23.0 mm), 10.5 mm (range, 7.4-13.8 mm), and 11.3 mm (7.1-15.3 mm), respectively. Additionally, the average occipital condyle medialization angle was 23° (range, 14-32°). Occipital condyles of men were significantly longer, wider, and taller (all comparisons, p < 0.05). The medialization angle was significantly steeper for women than men (p < 0.05). No measurement differences were appreciated by age. Conclusion: Our findings are similar to previous studies in the field; however, length appears slightly shorter. Further, measurement differences were appreciated by sex but not age. Thus, our measurement findings emphasize the importance of preoperative planning utilizing individual patient anatomy to ensure safe placement of occipital condyle screws for optimal outcomes.

Posterior occipitocervical (C0–3) fusion using polyaxial occipital condyle to cervical spine screw and rod fixation: a radiographic and cadaveric analysis

2010 ◽  
Vol 12 (5) ◽  
pp. 509-516 ◽  
Author(s):  
Bruce M. Frankel ◽  
Michael Hanley ◽  
Alex Vandergrift ◽  
Timothy Monroe ◽  
Steven Morgan ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Craniovertebral Junction ◽  
Basilar Invagination ◽  
Atlantoaxial Instability ◽  
Occipital Condyle ◽  
Anatomical Studies ◽  
Occipitocervical Fixation ◽  
Polyaxial Screws ◽  
Occipital Condyles ◽  
Ct Studies

Numerous conditions affect the occipitocervical junction requiring treatment with occipitocervical fixation. In this paper the authors present their technique of craniocervical fixation achieved with the cephalad extension of posterior C1–3 polyaxial screw and rods to polyaxial screws placed in the occipital condyles. They retrospectively analyzed occipital condyle morphology obtained from CT analyses of 40 patients with normal cervical spines, evaluated occipital condyle screw placement feasibility in 4 cadavers, and provided a case report of a 70-year-old woman with rheumatoid arthritis, basilar invagination, and atlantoaxial instability who was treated with this novel technique. Based on radiographic analysis of occipital condyle anatomy, they concluded that on average a 3.5-mm-diameter × 20- to 30-mm-long screw can be safely placed at an angle of 20–33° from the sagittal plane. Overall, measuring the condylar heights (mean [± SD] 10.8 ± 1.5 mm, range 8.1–15.0 mm), widths (mean 11.1 ± 1.4 mm, range 8.5–14.2 mm), lengths (20.3 ± 2.1 mm, range 15.4–24.6 mm), and angles (mean 32.8 ± 5.2°, range 20.2–45.8°) by using CT studies is an accurate and precise method. This finding correlates with the results of prior anatomical studies of occipital condyles and is important in the planning of craniovertebral junction surgery.

scholarly journals Biomechanics of Sports-Induced Axial-Compression Injuries of the Neck

2012 ◽  
Vol 47 (5) ◽  
pp. 489-497 ◽  
Author(s):  
Paul C. Ivancic
Keyword(s):  
Axial Compression ◽  
Time History ◽  
Occipital Condyle ◽  
Neck Injuries ◽  
Compression Force ◽  
Cervical Fractures ◽  
Human Cadavers ◽  
Clinical Awareness ◽  
Occipital Condyles ◽  
The Impact

ContextHead-first sports-induced impacts cause cervical fractures and dislocations and spinal cord lesions. In previous biomechanical studies, researchers have vertically dropped human cadavers, head-neck specimens, or surrogate models in inverted postures.ObjectiveTo develop a cadaveric neck model to simulate horizontally aligned, head-first impacts with a straightened neck and to use the model to investigate biomechanical responses and failure mechanisms.DesignDescriptive laboratory study.SettingBiomechanics research laboratory.Patients or Other ParticipantsFive human cadaveric cervical spine specimens.Intervention(s)The model consisted of the neck specimen mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Head-first impacts were simulated at 4.1 m/s into a padded, deformable barrier.Main Outcome Measure(s)Time-history responses were determined for head and neck loads, accelerations, and motions. Average occurrence times of the compression force peaks at the impact barrier, occipital condyles, and neck were compared.ResultsThe first local compression force peaks at the impact barrier (3070.0 ± 168.0 N at 18.8 milliseconds), occipital condyles (2868.1 ± 732.4 N at 19.6 milliseconds), and neck (2884.6 ± 910.7 N at 25.0 milliseconds) occurred earlier than all global compression peaks, which reached 7531.6 N in the neck at 46.6 milliseconds (P &lt; .001). Average peak head motions relative to the torso were 6.0 cm in compression, 2.4 cm in posterior shear, and 6.4° in flexion. Neck compression fractures included occipital condyle, atlas, odontoid, and subaxial comminuted burst and facet fractures.ConclusionsNeck injuries due to excessive axial compression occurred within 20 milliseconds of impact and were caused by abrupt deceleration of the head and continued forward torso momentum before simultaneous rebound of the head and torso. Improved understanding of neck injury mechanisms during sports-induced impacts will increase clinical awareness and immediate care and ultimately lead to improved protective equipment, reducing the frequency and severity of neck injuries and their associated societal costs.

Occipital Cervical Stabilization Using Occipital Condyles for Cranial Fixation: Technical Case Report

Neurosurgery ◽  
2009 ◽  
Vol 65 (6) ◽  
pp. E1216-E1217 ◽  
Author(s):  
Juan S. Uribe ◽  
Edwin Ramos ◽  
Ali Baaj ◽  
A. Samy Youssef ◽  
Fernando L. Vale
Keyword(s):  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Occipital Condyle ◽  
Occipitocervical Fixation ◽  
Vehicle Accident ◽  
Successful Case ◽  
Feasible Option ◽  
Craniocervical Instability ◽  
Fixation Points ◽  
Occipital Condyles

Abstract OBJECTIVE Presentation of a successful case of craniocervical stabilization involving a novel surgical technique using the occipital condyles as the sole cranial fixation points. CLINICAL PRESENTATION A 22-year-old man presented in a delayed fashion with neck pain after a motor vehicle accident. Evaluation revealed a type 2 odontoid fracture with pseudarthrosis and displacement of the dens superiorly and cranial settling of the dens. INTERVENTION The patient underwent posterior occipitocervical fixation with a polyaxial screw rod construct using the occipital condyle, C1 lateral mass, and C2 pars articularis for fixation. The patient had no immediate postoperative deficits. At the time of the 12-month follow-up examination, the patient was neurologically intact with a solid occipitocervical fusion. CONCLUSION Craniocervical stabilization using occipital condyle screws as the sole cephalad fixation points is a feasible option and can be used safely without neurovascular complication in the treatment of craniocervical instability.

scholarly journals Morphology and morphometric study of occipital condyles

2021 ◽  
Vol 9 (1.3) ◽  
pp. 7905-7911
Author(s):  
Asra Anjum ◽  
◽  
Gayathri Pandurangam ◽  
Supriya Garapati ◽  
Naveen Bandarupalli ◽  
...  
Keyword(s):  
Key Words ◽  
Foramen Magnum ◽  
Morphometric Study ◽  
Transcondylar Approach ◽  
Length Width ◽  
The Mean ◽  
Intercondylar Distance ◽  
Human Skulls ◽  
Occipital Condyles ◽  
Anatomical Parameters

Introduction: The occipital condyles are undersurface protruberances of the occipital bone in vertebrates, which articulate with the superior facets of the atlas vertebra. The condyles are oval or reniform in shape, and their anterior extremities directed forward and medially and are closer together than the posterior end. Aim: The aim of the study is to provide important anatomical parameters for lateral transcondylar approach. Materials and Methods: 200 occipital condyles in 100 dry human skulls ( 73 males and 27 females) were studied. The measured parameters included length, width, height, shape, anterior and posterior intercondylar distance, distance between basion and opesthion, distance from anterior tip of the condyle to the basion and opestion and distance from posterior tip to the basion and opesthion. Measurements were made using Vernier Callipers. Results: The mean length, width and height of the occipital condyles in males is greater than females. The anterior intercondylar distance is more in females whereas posterior intercondylar distance is more in males. The mean distance from basion to opesthion / anteroposteriordiamerer of foramen magnum is more in males than in females. The mean distance between the anterior tip of occipital condyles to basion is more in females than in males on both the sides. Conclusion: The knowledge of condylar anatomy helps the surgeon in making important decisions regarding extent and direction of condylar drilling and minimizing injury and retraction of neural structures. KEY WORDS: Occipital Condyles, Foramen Magnum, Intercondylar distance, Basion, Opesthion.

Cadaveric study for placement of occipital condyle screws: technique and effects on surrounding anatomic structures

2008 ◽  
Vol 9 (4) ◽  
pp. 347-353 ◽  
Author(s):  
Frank La Marca ◽  
Geoffrey Zubay ◽  
Thomas Morrison ◽  
Dean Karahalios
Keyword(s):  
Guidance System ◽  
Screw Placement ◽  
Occipital Condyle ◽  
Viable Option ◽  
Occipitocervical Fusion ◽  
Hypoglossal Canal ◽  
Occipitocervical Fixation ◽  
Fixation Devices ◽  
Fixation Techniques ◽  
Occipital Condyles

Object The occipital condyle has never been studied as a viable structure that could permit bone purchase by fixation devices for occipitocervical fusion. The authors propose occipital condyle screw placement as a possible alternative to conventional occipitocervical fixation techniques. Methods Six adult cadaver heads (12 total occipital condyles) were studied, and the StealthStation image-guidance system was used for preoperative planning of occipital condyle screw placement. Morphometric studies of the occipital condyle were performed. A 3.5-mm Vertex screw was then placed in the occipital condyle with image-guided assistance in 3 specimens. Operations in the remaining 3 specimens proceeded using anatomical markers and calculated degrees of angulation for screw placement with a free-hand technique. Postoperatively the cadaver heads were rescanned and reanalyzed to determine the success of screw placement and its effect on hypoglossal canal volume. Results All screws were successfully placed with no sign of lateral or medial cortical breach. Two screws had bicortical purchase. There was no change in hypoglossal canal volume in any specimen. Conclusions Occipital condyle screw placement is a safe and viable option for occipitocervical fixation and could be a preferred procedure in selected cases. However, further biomechanical studies are required to compare its reliability to other more established techniques.

scholarly journals SURGICAL TREATMENT OF MENINGIOMA WITH VENTRAL AND VENTROLATERAL LOCALIZATION IN THE REGION OF THE FORAMEN MAGNUM

2018 ◽  
pp. 84
Author(s):  
Luka Berilažić ◽  
Nebojša Stojanović ◽  
Radisav Mitić ◽  
Aleksandar Kostić ◽  
Zvonko Dželebdžić
Keyword(s):  
Spinal Canal ◽  
Complete Removal ◽  
Foramen Magnum ◽  
Posterolateral Approach ◽  
Surgical Approaches ◽  
Occipital Condyle ◽  
Atlantoaxial Joint ◽  
Bone Removal ◽  
Occipitocervical Fixation ◽  
Occipital Condyles

Meningiomas localized in the ventral part of the foramen magnum always represent a surgical challenge. Analysis was performed on the surgical approach to meningiomas with ventral localization in the craniocervical region in 6 patients. Two posterolateral surgical approaches were used, depending on whether the tumor was at the level of the foramen magnum or it transited into the cervical spinal canal. In the case of a tumor at the level of the foramen magnum, posterolateral approach was used, with the suboccipital bone removal, and removal of part of the occipital condyles, with the resection of the atlas arch and mobilization of a.vertbralis. In tumors propagated in the spinal canal, the same resection of the occipital bone and occipital condyle was done, with the removal of the atlas and part of the atlantoaxial joint. Due to destabilization, occipitocervical fixation was performed in the second posterolateral approach. The posterolateral approach with the suboccipital removal of the bones and the atlas or, if necessary, with the resection of the occipital condyle or atlantoaxial joint, enables a good ventral separation of the tumor attachment and subsequent gradual complete removal. Fixation is required in the event of a removal of the atlantoaxial joint or removal of more than half of the occipital condyle. Posterolateral approach is an absolute indication in all cases of the ventral and ventrolateral localization of meningiomas in the area of the cervico-occipital junction, because it provides complete visualization of the tumor and allows for its safe removal.

scholarly journals Anatomical and clinical correlates of the precondylar tubercle

2014 ◽  
Vol 31 (03) ◽  
pp. 182-186 ◽  
Author(s):  
A. Jaffar
Keyword(s):  
Anterior Margin ◽  
Surgical Intervention ◽  
Foramen Magnum ◽  
Occipital Condyle ◽  
Radiographic Images ◽  
Radiographic Appearance ◽  
Clinical Correlates ◽  
Clinical Community ◽  
Spiral Computerized Tomography ◽  
Occipital Condyles

Abstract Introduction: The possible presence of the precondylar tubercle should be considered in order to avoid misinterpretation in radiographic images and confusion during surgical intervention. This study is aimed to describe and report the frequency of the precondylar tubercle and similar variations at the anterior margin of foramen magnum in order to alert the clinical community of their presence and of the possible associated variations. Materials and Methods: Fifty dry skulls were examined for variations at the anterior margin of foramen magnum. One skull with bilaterally prominent precondylar tubercles was studied using a spiral computerized tomography in order to demonstrate the radiographic appearance of the tubercle. Results: Precondylar tubercles were observed in 10% of the skulls. Other simulating observations included the presence of a midline spur, bilateral depression anteromedial to the occipital condyles, third occipital condyle, and a partly divided occipital condyle. In 89% of the cases these variations were associated with septation of the hypoglossal canal. Conclusion: The presence of a mere precondylar tubercle is not expected to produce neurological manifestations. However, its possible association with other variations should be considered. The size and location of the precondylar tubercle might evade plain radiographic films, but it can be readily revealed in axial computerized tomograms.

scholarly journals Safe trajectory for an occipital condyle screw: A computer simulation study

2019 ◽  
Vol 27 (3) ◽  
pp. 230949901987954
Author(s):  
Zhen-Qi Lou ◽  
Yang Wang ◽  
Ding-Li Xu ◽  
Guo-Qing Li ◽  
Wei-Hu Ma ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Computed Tomographic Angiography ◽  
Screw Placement ◽  
Occipital Condyle ◽  
Anatomical Structures ◽  
Screw Insertion ◽  
Computed Tomographic ◽  
Left And Right ◽  
Tomographic Angiography ◽  
Occipital Condyles

Objective: The purpose of this study was to evaluate the feasibility of posterior occipital condyle screw (OCS) placement analysis of the safe trajectory area for screw insertion. Methods: Computed tomographic angiography scans of patients (46 males and 27 females) with normal occipitocervical structures were obtained consecutively. Vertebral artery (VA)-occiput distance <4.0 mm was defined as “unfeasible” for OCS fixation, and occipital-atlas angulation was measured to assess the feasibility of screw placement. Next, the placement of 3.5 mm diameter OCS was simulated, the probability of breach of structures surrounding occipital condyles was calculated, and placement parameters were analyzed. Results: OCS placement was feasible in 91.1% (133/146) of occipital condyles, and the feasible probability also presented a significant sex-related difference: The probability was higher for males than for females (95.7% vs. 83.3%, p < 0.05). The incidence of anatomical structures injured under screw placement limitation was 18.8% (VA), 81.2% (hypoglossal canal), 59.4% (occipital-atlas joint), and 40.6% (occiput bone surface). There were no significant differences between the left and right condyles in relation to the measured parameters ( p > 0.05). The screw range of motion was significantly smaller in females than in males ( p < 0.05). The feasibility of OCS placement and OCS range of motion were significantly greater in the kyphosis group (>5°) than in the other two groups ( p < 0.05). Conclusion: OCS placement is a feasible technique for occipital-cervical fusion. The male group and occipitocervical region kyphosis group had a wider available space for OCS placement. Tangent angulation may be useful for the accurate and safe placement of an OCS.

A microsaur from the Mississippian of illinois and a standard format for morphological characters

1999 ◽  
Vol 73 (5) ◽  
pp. 908-923 ◽  
Author(s):  
R. Eric Lombard ◽  
John R. Bolt
Keyword(s):  
Vertebral Column ◽  
Sister Group ◽  
Morphological Characters ◽  
Occipital Condyle ◽  
Sister Group Relationship ◽  
Neural Arch ◽  
Standard Format ◽  
Caudal Vertebrae ◽  
Early Tetrapods ◽  
Occipital Condyles

The oldest known microsaur is preserved in a nodule from the Kinkaid Formation (Mississippian; Elvirian) collected near Goreville, Illinois. At least eight individuals are represented: three by partial skulls plus vertebral column segments with associated limb elements, and five by postcrania only. Skulls are crushed, incomplete, and exposed mainly in palatal view. Palatal bones are denticulate and the palatine has in addition a single large tooth. The basipterygoid process is laterally directed and the basipterygoid joint is open. The atlas carries large articulating facets for proatlantes, a pair of which are identifiable in one specimen. These features have not been found previously in a microsaur. All vertebral segments are dominated by a biconcave pleurocentrum; sutures between the pleurocentrum and neural arch are visible in presacral vertebrae. Distinctive microsaurian intercentra occur between all presacral pleurocentra. Their presence reinforces the hypothesis that microsaur intercentra are homologous with those of other early tetrapods. Caudal vertebrae retain separate haemal arches and some have ribs.Observed microsaur synapomorphies include: atlas with large median odontoid; atlas with concave lateral facets for occipital condyle; paired occipital condyles that are broad and concave; and thin, straplike intercentra. No observed features support a sister-group relationship with any other microsaur species, or placement within any higher level microsaur group. Because significant portions of the skeleton are missing or inaccessible, the Goreville microsaur is not formally named. A standardized, hierarchical format for skeletal characters is introduced that facilitates data sharing and comparison and fosters rapid archiving and retrieval.

scholarly journals Anatomical and Radiological study of the posterior cranial base in relationship to occipital condyles and Foramen magnum

2020 ◽  
Vol 11 (3) ◽  
pp. 3528-3532
Author(s):  
Sharmila Aristotle ◽  
Balaji Ramraj ◽  
Shantanu Patil ◽  
Sundarapandian Subramanian
Keyword(s):  
Clinical Importance ◽  
Diagnostic Procedures ◽  
Cranial Base ◽  
Ct Images ◽  
Foramen Magnum ◽  
Ct Scans ◽  
Surgical Approaches ◽  
Occipital Condyle ◽  
Mortality And Morbidity ◽  
Occipital Condyles

Detailed morphometric analysis is required for various surgical approaches in the craniovertebraljunction. High mortality and morbidity are anticipated for the surgical procedures when undertaken without in-depth anatomical knowledge. With so much clinical importance in this area, our study will present a thorough understanding in terms of skull and CT values. The main aim of this study is to give the morphometric details of occipital condyles and foramen magnum in cadaveric skulls and CT scans. Seventy dried human skulls and 70 CT images on the three-dimensional volume-rendered reconstruction of the skull base was used for this study. The length and width of the occipital condyle of right and the left side was 22.21 ±5.20 mm; 22.05±4.83 mm; 12.57 ± 2.50 and 12.68 ± 2.92mm respectively in cadaver skull. The length and width of occipital condyles in CT scans for right and left side was 21.61 ± 3.09 mm; 21.58 ± 3.50 mm; 13.04 ± 1.58 mm and 13.13 ± 2.54 mm respectively. The Anteroposterior and transverse diameters of the foramen magnum in cadaveric skulls and CT images was 33.17 ± 7.23; 29.22 ± 6.17; 34.15 ± 2.88 and 28.14 ± 2.43 mm respectively. Each surgical approach and the radiological diagnostic procedures have their limitations. Moreover, analysis of cranial base dimensions of occipital condyles and foramen magnum can be considered as a reliable method for sex determination. Hence this study will a useful guide for surgeons, radiologists, anthropologists and forensic experts.

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