Management of occipitocervical junction and upper cervical trauma

The Feasibility of Condylar Screws for Occipitocervical Fusion in Arabs: Computed Tomography-Based Morphometric Study

Study DesignRetrospective, cross-sectional study.ObjectivesOccipitocervical fusion is indicated for various conditions. Some techniques require placement of screws in the occipital condyle. The objective of this study was to analyze the morphometric features of the occipital condyle among Arabs.MethodsComputed tomography (CT)-based morphometric analysis of occipital condyles of 200 Arab skeletally mature patients (400 condyles) was done. Axial width of at least 8 mm and coronal height of at least 6.5 mm are the cutoff values for feasibility of condylar screw placement.ResultsThe mean age of the patients was 48.0 ± 18.3 years. Males were 53.5% (107) of the sample. The mean axial condylar width and length were 8.5 ± 1.5 mm and 20.3 ± 2.6 mm, respectively, while the mean axial screw angle was 35.9° ± 5.5° from midline. The mean sagittal condylar length and height were 16.1 ± 1.9 mm and 8.8 ± 1.5 mm, respectively. The mean condylar coronal height was 8.2 ± 1.4 mm. Based on axial width and coronal height measurements, 150 (37.5%) condyles could safely fit a 3.5 mm condylar screw. One hundred and four (55.9% female condyles) condyles cannot fit a screw in females, while 46 (21.5% male condyles) condyles cannot fit a screw in males.ConclusionsCondylar screw for occipitocervical fusion is feasible for the majority of Arabs in our sample; however, this applies to slightly less than half of the female condyles. Detailed preoperative radiological planning is critical to avoid complications related to occipital condyle screw placement.

Higher incidence of delayed bone fusion for atlantoaxial fusion versus occipitocervical fusion with navigation system

BACKGROUND

Due to the high stresses placed on the upper cervical spinal region, achieving firm fixation and solid bony fusion is essential for good surgical outcomes. However, few reports have addressed bony fusion in procedures involving this region. The present investigation evaluated bony union in fusion procedures for surgical treatment of the upper cervical spinal region and searched for factors associated with fusion failure.

METHODS

The medical data of 84 consecutive patients (38 male and 46 female; mean age: 68.7 years) who underwent upper cervical spinal fusion surgery were retrospectively examined. The surgical techniques used were occipitocervical (O-C) fusion in 45 patients and atlantoaxial fusion with trans-articular screws in 39 patients. To determine the incidence of bony union, the cohort was divided into O-C fusion and atlantoaxial fusion groups and examined for the presence of delayed bony union. Logistic regression models were employed to analyze the prevalence, characteristics, and risk factors of delayed bony union.

RESULTS

Overall, 20.2% of upper cervical spinal fusion surgery patients experienced delayed bony union. In comparisons of the O-C fusion and atlantoaxial fusion groups, we observed no remarkable differences for age, gender, or steroid use, although rheumatoid arthritis was significantly more common in the O-C fusion group (p < 0.001). Bony fusion rates tended to be higher in the O-C fusion group (86.6%) than in the atlantoaxial fusion group (71.7%). Multivariate analysis identified atlantoaxial fusion to be more strongly associated with delayed bony union (odds ratio: 2.6).

CONCLUSION

Approximately 20% of patients undergoing upper cervical spinal fusion surgery experienced delayed bony union. With an odds ratio of 2.6, atlantoaxial fusion was strongly related to this complication.

Management of Type III Occipital Condyle Fractures

Background/Objectives: Occipital condyle fractures (OCFs) can be seen in around 4-19% of patients who suffer from cervical spine trauma. Anderson and Montesano system type III OCFs, which are avulsion fractures, are potentially unstable and operative. This study evaluates the management of type III OCFs at our institution over a 22-year period. Methods: This retrospective study reviewed all cases of type III OCFs at our institution from July 2001 to March 2023, identified via imaging reports. Using the in-house radiology imaging informatics system "Doris" (Dig Our Radiology Information System), reports containing the terms subluxation, avulsion, unstable, or type 3/III with occipital condyle, occipital condylar, occipital fx, or occipital fracture were collected. We also searched for Montesano type III/3 fracture. Electronic medical records were used to collect clinical and demographic data. Patients evaluated by the neurosurgical team with at least 1 month of follow-up were included in the analysis. Results: A total of 563 patients were identified with type III OCFs. A total of 56 patients met the inclusion criteria. The majority (91%, 51/56) were treated conservatively with cervical orthosis. A small subset (8.9%, 5/56) underwent occipito-cervical fusion. Three had concomitant unstable C1 fractures, while the other two had significant coronal deformity associated with their type III OCF. Conclusions: At our institution, type III OCFs are predominantly managed with cervical orthosis. Only those with an associated malalignment of the occipito-cervical joint underwent fusion. These findings suggest that most type III OCFs can be treated conservatively with orthosis once stability is confirmed with an upright radiograph.

Management of combined atlas and axis fractures: a systematic review

Background

Combined atlas-axis fractures are rare occurrences with substantially higher rates of neurologic deficits compared with isolated injuries. Given the intricate anatomic relationship between the atlas and axis vertebra, variable fracture patterns may occur, warranting special considerations from surgeons.

Methods

A systematic search of PubMed and EMBASE was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies on acute combined atlas-axis fractures that provided data on patient demographics, presentation (injury mechanism, neurologic deficits, fracture type), management, complications, and study conclusions were reviewed.

Results

A total of 22 articles published from 1977 to 2022, comprising 230 patients, were included in the final analysis. Thirty-seven of the 213 patients (17%) presented with neurologic deficits. The most common atlas injuries were posterior arch fractures (54/169 patients; 32%), combined posterior arch/anterior arch fractures (44/169 patients; 26%), and anterior arch fractures (43/169 patients; 25%). The most common axis injuries were type II odontoid fractures (115/175 patients; 66%). Of the 127 patients managed operatively (127/230 patients; 55%), 45 patients (35%) were treated with C1-C2 posterior spinal fusion, 33 patients (26%) were treated with odontoid screw fixation and anterior/posterior C1-C2 trans-articular screws, 16 patients (13%) were treated with occiputocervical fusion and 12 patients (9%) were treated with odontoid screw fixation alone.

Conclusions

Management strategies are generally based on the type of axis fracture as well as the condition of the transverse ligament. Patients with stable fractures can be successfully managed nonoperatively with a cervical collar or halo immobilization. Combined atlas-axis fractures with an atlantodental interval >5 mm, C1 lateral mass displacement >7 mm, C2-C3 angulation >11° or an MRI demonstrating a disrupted transverse ligament are suggestive of instability and are often successfully managed with surgical intervention. There is no consensus regarding surgical technique.

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

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.

Upper Cervical Spine Injuries: Profile and Management of 120 Cases

OBJECTIVES

To identify the profile and management of patients with upper cervical spine injury.

METHODS

Retrospective cohort study of patients with upper cervical spine injuries managed at Hospital da Restauração between 2014 and 2020.

RESULTS

It presents the profile of 145 injuries recorded by location and classification among the 120 patients, and the management performed. Men are more affected than women, almost half of the patients (42.5%) were aged 16 to 29 years. Neurological deficit was present in 18 cases (15%). Twenty cases presented injury involving the level C1. Most injuries (109 [90.8%]) occurred at the C2 level, the most frequent of which were as follows: isolated type II odontoid fracture (29.2%), miscellaneous fracture of C2 (20%), and isolated hangman's fracture (13.3%). The most used management in type II odontoid fracture was C1-C2 posterior arthrodesis (17/42) followed by odontoid osteosynthesis (12/42). Regarding isolated hangman's fracture, conservative management was performed in 37.5% (6/16), and the technical approach most performed was anterior C2-C3 discectomy and interbody fusion (5/16).

CONCLUSIONS

Upper cervical spine injury has a higher prevalence in young men and is most often caused by traffic accidents. The main level affected is C2, and type II odontoid fracture is the most frequent subtype. C1 injury is related to conservative treatment, while C2 or combined C1-C2 injury is related to surgical approach. The management of these injuries is mainly performed with surgical treatment, with C1-C2 posterior arthrodesis and anterior odontoid osteosynthesis representing most of the approaches.

Minimally invasive lateral occipitocervical fixation: case series and technique description

PURPOSE

Occipitocervical junction (OCJ) instability is commonly treated with fixation via open posterior approach. The use of intraoperative navigation allows us to perform occipitocervical fixation via minimally invasive approach. We report a series of patients treated with percutaneous occipitocervical fixation, describing the surgical procedure in detail and discussing the technique.

METHODS

We prospectively enrolled 8 patients affected by OCJ instability secondary to trauma and rheumatoid arthritis. Traumatic patients were preoperatively evaluated with CT scan and MRI scan if needed. Rheumatoid arthritis group was evaluated with both CT and MR. Patients underwent percutaneous occipitocervical fixation with the assist of intraoperative 3D imaging and navigation. All patients were functionally and radiologically evaluated pre-, at 6 weeks, and at 1 year postoperatively.

RESULTS

Percutaneous occipitocervical fixation was successfully performed in all of the patients. 33 screws were placed. 29 (87.88%) were placed without any pedicle breach. In 3 (9.09%) screws we observed a minor; and in 1 (3.03%) screw we observed a major pedicle breach. We did not have any postoperative complications.

CONCLUSIONS

Described method of occipitocervical fixation is a minimally invasive method that has a similar outcome to the open technique. It requires the experience in open techniques and the assist of intraoperative 3D imaging and navigation to be performed efficiently.

Atlantoaxial posterior screw fixation using intra-operative spinal navigation with three-dimensional isocentric C-arm fluoroscopy

PURPOSE

Intra-operative image acquisition coupled with navigation aims to increase screw placement accuracy, and it is particularly helpful in complex spinal procedures. The aim of this study is to analyze the accuracy and reliability of posterior atlanto-axial fixation using spinal navigation combined with intra-operative 3D isocentric C-arm.

METHODS

We retrospectively reviewed all patients presenting with C1-C2 instability and treated by posterior atlanto-axial fixation in our center between December 2016 and September 2018. Screw positioning was guided by intra-operative navigation, registered with surface matching procedure on a previously obtained CT scan and controlled by intra-operative 3D isocentric C-arm. Age, sex, pre- and post-operative neurological status, duration of surgery, presence/absence of vertebral artery injury, and screw placement were retrospectively collected from patients' records. All patients underwent clinical and radiological follow-up at three months after surgery. Radiological assessment of screw positioning was performed by an independent radiologist using the Gertzbein and Robbins grading.

RESULTS

N = 11 (7F, 4 M) consecutive patients were included, with a mean age of 72 years (range from 51 to 85). N = 44 navigated screws were inserted and controlled with intra-operative 3D fluoroscopy at the end of the procedure. An acceptable screw positioning (Gertzbein-Robbins grade A and B) was obtained in all cases (100%). No vertebral artery injury was observed. Mean operating time was 123 minutes. At three months, no screw loosening or displacement was observed.

CONCLUSION

In our experience, spinal navigation coupled with intra-operative 3D fluoroscopy proved to be reliable and safe for C1-C2 screw placement.

Minimalistic reconstruction of exposed skull in a complex craniovertebral polytrauma

Background:

In stable craniovertebral injuries complicated by polytrauma, rigorous spinal immobilization is essential for neuroprotection. Scalp and forehead reconstruction in these circumstances are safest when performed under local anesthesia, maintaining cervical immobilization.

Case Description:

A sizeable 10 × 6.5 cm forehead defect was reconstructed utilizing regenerative principles under local anesthesia and sedation in a 54-year-old woman. After adequate debridement of gangrenous soft tissues, exposed outer skull bones were trephined, forehead defect covered with a synthetic biomaterial, and the patient was discharged thereafter. Granulating neodermis regenerated within the biomaterial over the next 6 weeks. Weekly platelet-rich plasma injections along the wound margins facilitated wound regeneration. Dimensions reduced by two-thirds to 6.5 × 3.5 cm with wound regeneration and contraction, while granulating neodermis covered the remaining skull-bones. Split skin-grafting over the neodermis ensured satisfying long-term results, with similar color, texture, soft-tissue thickness, and sensation. Multiple occipitocervical, spinal, scapular, and rib fractures healed well with strict immobilization.

Conclusion:

Good long-term results were achieved with significantly reduced dangers, complications, hospitalization, and costs than traditional reconstructive flap surgeries. Minimalistic reconstruction utilizing tissue engineering and regenerative medicine principles appears beneficial for patients with grave spinal injuries.

Tectorial Membrane Injury, Frequently Identified in Adult Trauma Patients Who Undergo Occipital-Cervical Fusion for Craniocervical Instability

Background In the absence of frank craniocervical dissociation, there is a lack of consensus regarding what patterns of craniocervical junction ligamentous injuries require occipital-cervical fusion. This study was undertaken to examine the integrity of the craniocervical junction ligaments and analyze clinical outcomes in patients who underwent occipital-cervical fusion for craniocervical junction injury. Methods Adult patients requiring occipital-cervical fusion were identified retrospectively utilizing keyword searches in cervical computed tomography and magnetic resonance imaging reports between 2012 and 2020 using Nuance mPower software (Nuance, Burlington, MA). The cervical magnetic resonance imaging examinations for these patients were reviewed for craniocervical ligamentous injury by two neuroradiologists. Descriptions of craniocervical junction injuries, demographic information, clinical history, surgical management, and global outcomes were recorded. Results Nine adult patients were identified with an acute, post-traumatic craniocervical junction injury requiring occipital-cervical fusion. All nine patients demonstrated a ligamentous tear in at least one of the four major craniocervical junction ligaments - the occipital condylar-C1 capsular ligaments, alar ligaments, tectorial membrane, and posterior atlantooccipital membrane. The tectorial membrane was the most commonly torn ligament followed by the alar ligament(s), posterior atlantooccipital membrane, and capsular ligament(s). There was wide variability in the number of major craniocervical junction ligaments torn, ranging from one ligament to all four ligaments. Four patients suffered persistent neurologic deficits following surgery. Conclusion Craniocervical injury is best evaluated by cervical magnetic resonance imaging. In the absence of overt craniocervical dissociation, we propose that an injury of the tectorial membrane in the adult population may indicate patients with significant craniocervical instability, possibly necessitating occipital-cervical fusion.

Morphometric analysis of occipital condyles using alternative imaging technique

PURPOSE

The occipital condyles (OCs) are crucial anatomical structures in the cranial base. To our knowledge, there is no cone beam computed tomography (CBCT)-based study on the morphometric analysis of OCs. The aim of this study was to evaluate the morphometric analysis of OCs using CBCT.

METHODS

CBCT images of 200 OCs from 100 patients of which 39 males and 61 females in the age group of 18-67 years were included in the study population. Linear and angular measurements of OCs were performed.

RESULTS

The average OC width, length, height, sagittal angle, and effective height were 10.3 ± 1.3 mm, 19.6 ± 2.0 mm, 9.1 ± 1.4 mm, 7.4 ± 1.7 mm, and 35.3 ± 5.2 mm. Condylar width and sagittal angle measurements were found significantly different between the right and left sides; and were not found significant difference between the right and left sides in the measurements of condylar height, length, and effective height. Also the average intercondylar anterior distance (ICAD), intercondylar posterior distance (ICPD), distance between the basion and the anterior apex of the occipital condyle (B-AAOC), distance between the basion and posterior apex of the occipital condyle (B-PAOC), distance between the opisthion and anterior apex of occipital condyle (O-AAOC), and distance between the opisthion and posterior apex of occipital condyle (O-PAOC) were 20.9 ± 1.5 mm, 44.0 ± 2.0 mm, 12.3 ± 1.9 mm, 34.5 ± 4.2 mm, 29.8 ± 1.7 mm, and 27.0 ± 2.1 mm. There was not significant difference in the morphometric measurements among age groups. All morphometric measurements showed a significant difference depending on gender.

CONCLUSIONS

The morphometric evaluation of OCs may be effectively examined using CBCT. Linear and angular measurements data of OCs in the present study may be used as a reference database for future morphometric and surgical investigations.