OBJECTIVE: Autologous iliac bone is commonly used as a bone graft material to achieve solid fusion in craniocervical junction (CVJ) surgery. However, the developing iliac bone of children is less than ideal as a bone graft material. The matured rib bone of children presents a potential substitute material for iliac bone. The aim of this study was to evaluate the efficacy of autologous rib grafts for craniocervical junction surgery in children.
METHODS: The outcomes of 10 children with abnormalities of the craniocervical junction who underwent craniocervical junction surgery between January 2020 and December 2022 were retrospectively reviewed. All patients underwent posterior fusion and internal fixation surgery with autologous rib grafts. Pre- and post-operative images were obtained and clinical follow-ups were conducted to evaluate neurological function, pain level, donor site complications, and bone fusion rates.
RESULTS: All surgeries were successful. During the 8- to 24-month follow-up period, all patients achieved satisfactory clinical results. Computed tomography at 3-6 months confirmed successful bone fusion and regeneration of the rib defect in all patients with no neurological or donor site complications.
CONCLUSIONS: Autologous rib bone is a safe and effective material for bone grafting in craniocervical junction fusion surgery for children that can reduce the risks of donor site complications and increase the amount of bone graft, thereby achieving a higher bone fusion rate.

UNASSIGNED: The purpose of this study was to determine effect sizes (ES) for changes in self-reported measures of musculoskeletal pain and dysfunction resulting from the one-to-zero method using a repeated measures study design.
UNASSIGNED: Twenty participants presenting with articular dysfunction of the occipito-atlantal (C0-C1) complex were treated using the one-to-zero method, a high-velocity low-amplitude thrust administered between the C0-C1 complex before treating other restrictive segments in a cephalocaudal direction. The participants completed online questionnaires using Google Forms that assessed aspects of the biopsychosocial model of pain at baseline and within a week after treatment. The questionnaires included the following: (1) Demographic and Health Behavior Survey; (2) Neck Bournemouth Questionnaire (NBQ) or Neck Disability Index (NDI); (3) Beck Anxiety Index (BAI); (4) Insomnia Severity Index (ISI); and (5) 36-Item Short Form Health Survey (SF-36). Paired t test or Wilcoxon signed ranks test was performed, dependent on normality. Cohen\'s d values were calculated for each questionnaire score (0.20 indicative of small; ≥0.50 medium; and ≥0.80 large ES).
UNASSIGNED: The NDI, NBQ, BAI, and ISI had a large ES (all d ≥ 0.80). In the SF-36, 4 subscales had a small to near-medium ES, 1 subscale had a medium to near-large ES, and the remaining 2 had a large ES (d ≥ 0.80). The physical and mental component summary had a large (d = 0.88) and small ES (d = 0.35), respectively.
UNASSIGNED: The effect sizes suggest the one-to-zero treatment induces change in various aspects of the biopsychosocial model.

The cranio-vertebral junction (CVJ) was formerly considered a surgical \"no man\'s land\" due to its complex anatomical and biomechanical features. Surgical approaches and hardware instrumentation have had to be tailored in order to achieve successful outcomes. Nowadays, thanks to the ongoing development of new technologies and surgical techniques, CVJ surgery has come to be widely performed in many spine centers. Accordingly, there is a drive to explore novel solutions and technological nuances that make CVJ surgery safer, faster, and more precise. Improved outcome in CVJ surgery has been achieved thanks to increased safety allowing for reduction in complication rates. The Authors present the latest technological advancements in CVJ surgery in terms of imaging, biomaterials, navigation, robotics, customized implants, 3D-printed technology, video-assisted approaches and neuromonitoring.

Porcine models in injury biomechanics research often involve measuring head or brain kinematics. Translation of data from porcine models to other biomechanical models requires geometric and inertial properties of the pig head and brain, and a translationally relevant anatomical coordinate system (ACS). In this study, the head and brain mass, center of mass (CoM), and mass moments of inertia (MoI) were characterized, and an ACS was proposed for the pre-adolescent domestic pig. Density-calibrated computed tomography scans were obtained for the heads of eleven Large White × Landrace pigs (18-48 kg) and were segmented. An ACS with a porcine-equivalent Frankfort plane was defined using externally palpable landmarks (right/left frontal process of the zygomatic bone and zygomatic process of the frontal bone). The head and brain constituted 7.80 ± 0.79% and 0.33 ± 0.08% of the body mass, respectively. The head and brain CoMs were primarily ventral and caudal to the ACS origin, respectively. The mean head and brain principal MoI (in the ACS with origin at respective CoM) ranged from 61.7 to 109.7 kg cm2, and 0.2 to 0.6 kg cm2, respectively. These data may aid the comparison of head and brain kinematics/kinetics data and the translation between porcine and human injury models.

The craniovertebral junction (CVJ) is a complex transition area between the skull and cervical spine. Pathologies such as chordoma, chondrosarcoma and aneurysmal bone cysts may be encountered in this anatomical area and may predispose individuals to joint instability. An adequate clinical and radiological assessment is mandatory to predict any postoperative instability and the need for fixation. There is no common consensus on the need for, timing and setting of craniovertebral fixation techniques after a craniovertebral oncological surgery. The aim of the present review is to summarize the anatomy, biomechanics and pathology of the craniovertebral junction and to describe the available surgical approaches to and considerations of joint instability after craniovertebral tumor resections. Although a one-size-fits-all approach cannot encompass the extremely challenging pathologies encountered in the CVJ area, including the possible mechanical instability that is a consequence of oncological resections, the optimal surgical strategy (anterior vs posterior vs posterolateral) tailored to the patient\'s needs can be assessed preoperatively in many instances. Preserving the intrinsic and extrinsic ligaments, principally the transverse ligament, and the bony structures, namely the C1 anterior arch and occipital condyle, ensures spinal stability in most of the cases. Conversely, in situations that require the removal of those structures, or in cases where they are disrupted by the tumor, a thorough clinical and radiological assessment is needed to timely detect any instability and to plan a surgical stabilization procedure. We hope that this review will help shed light on the current evidence and pave the way for future studies on this topic.

The anatomical features of the atlanto-occipital joint can be potentially useful in re-associating or excluding crania to atlases in commingled remains. This study investigated whether linear measurements and the 3-dimensional (3D) surface of occipital condyles and articular facets of atlases can represent valid insights for this purpose.
The variations among eight corresponding linear distances were analyzed in a sample of 150 individuals through six supervised machine learning techniques attempting to develop classifiers able to identify elements belonging to the same individual. Furthermore, a 3D analysis was conducted on the articular surfaces through superimpositions of 3D models of corresponding and non-corresponding crania and atlases obtained by using respectively stereophotogrammetry and laser scanning. This analysis investigated differences in terms of point-to-point distances (Root Mean Square, RMS) of superimposed 3D surfaces.
None of the six machine learning techniques were able to correctly detect a satisfying percentage of correspondent pairs in the overall sample by using the linear variables. The 3D analysis of the articular surfaces found RMS values over 0.53 mm only for superimposed non-corresponding surfaces, which sets a threshold value to identify 32% of incorrect pairs.
The re-association of cranium to atlas proved to be challenging and hardly possible when considering only metric variables. However, the 3D geometry of the articular surfaces represents a valid variable for this purpose and 3D analyses pave the way for an initial exclusion of incorrect re-associations, thus should not be considered as a re-association method per se, but as an exclusionary screening technique.

Our previous study suggested that atlanto-occipital instability (AOI) is common in patients with type II basilar invagination (II-BI).
To further understand the pathogenesis of AOI in Chiari malformations (CM) and CM + II-BI through systematic measurements of the bone structure surrounding the craniocervical junction.
Computed tomography data from 185 adults (80 controls, 63 CM, and 42 CM + II-BI) were collected, and geometric models were established for parameter measurement. Canonical correlation analysis was used to evaluate the morphological and positional relationships of the atlanto-occipital joint (AOJ).
Among the 3 groups, the length and height of the condyle and superior portion of the lateral masses of the atlas (C1-LM) were smallest in CM + II-BI cases; the AOJ had the shallowest depth and the lowest curvature in the same group. AOJs were divided into 3 morphological types: type I, the typical ball-and-socket joint, mainly in the control group (100%); type II, the shallower joint, mainly in the CM group (92.9%); and type III, the abnormal flat-tilt joint, mainly in the CM + II-BI group (89.3%). Kinematic computed tomography revealed AOI in all III-AOJs (100%) and some II-AOJs (1.5%) but not in type I-AOJs (0%). Morphological parameters of the superior portion of C1-LM positively correlated with those of C0 and the clivus and significantly correlated with AOI.
Dysplasia of the condyle and superior portion of C1-LM exists in both CM and II-BI cases yet is more obvious in type II-BI. Unstable movement caused by AOJ deformation is another pathogenic factor in patients with CM + II-BI.

The far lateral approach has been developed to access lesions at the craniocervical junction and upper cervical spinal canal. Associated morbidity triggered the development of less invasive tailored approaches.
In this lateral approach to the craniocervical junction, the occipital condyle is kept intact, vertebral artery manipulation is minimized, and the sigmoid sinus is not skeletonized. A linear incision through skin and muscles and use of an abdominal wall fat graft minimize the risk of cerebrospinal fluid leakage.
The exposure provided is sufficient for the majority of tumors in this region and allows for low complication rates.

OBJECTIVE: Craniocervical dissociation is a rare and life-threatening injury that results from a significant hyperflexion-hyperextension force. Occult craniocervical dissociation is defined as an unstable craniocervical injury in the absence of atlanto-occipital joint space widening or other skull base line abnormality. The early and accurate diagnosis of craniocervical dissociation is crucial since the early diagnosis and subsequent stabilization with occipital-cervical fusion has been shown to reduce neurologic morbidity and mortality. Several normative skull base lines have been developed to predict craniocervical dissociation. The purpose of our study was to measure the atlanto-occipital joint space and four other common skull base lines in patients who underwent occipital-cervical fusion for post-traumatic craniocervical instability.
METHODS: Patients who underwent occipital-cervical fusion for craniocervical injury were identified retrospectively using a keyword search of radiology reports using Nuance mPower software. The cervical CT and MRI exams for these patients were reviewed and the atlanto-occipital joint space, Powers ratio, Wackenheim line, posterior axial line, and basion dens interval were measured. Detailed descriptions of craniocervical ligament injuries on MRI were recorded along with patient demographic information, clinical history, management, and outcome.
RESULTS: Nine adult patients who underwent occipital-cervical fusion for an acute craniocervical injury were identified. Six patients demonstrated an atlanto-occipital joint space measuring 2 mm or less on cervical spine CT with no additional abnormality in the Powers ratio, Wackenheim line, posterior axial line, or basion-dens interval. Three patients demonstrated widening of the atlanto-occipital joint space with two patients demonstrating an abnormality in at least two additional skull base lines. Clinical outcomes were variable with nearly half of the patients demonstrating persistent neurologic deficits, including one quadriplegic patient.
CONCLUSIONS: A normal atlanto-occipital joint space and skull base line measurements on cervical CT demonstrated a low predictive value for detecting unstable craniocervical injuries. Occult craniocervical dissociation was present in two-thirds of patients who underwent occipital cervical fusion for acute, craniocervical trauma. A high clinical and radiologic index of suspicion for craniocervical trauma with subsequent follow-up cervical MRI to directly evaluate ligamentous integrity is necessary to accurately diagnose and triage patients with high velocity trauma.

OBJECTIVE: The concept of enhanced recovery after surgery (ERAS) has been proposed to provide guidance for the improved postoperative rehabilitation of patients with occipitocervical region disease (ORD).
METHODS: This study retrospectively investigated 208 consecutive patients (116 men and 92 women) ranging in age from 22 to 76 years with ORD between July 2014 and June 2017 in our medical center, who were divided into three groups that received different preoperative, intraoperative, and postoperative management plans: traditional group (n = 73), ameliorated group (n = 70), and ERAS group (n = 65). We compiled a range of data relating to demographics and postoperative changes in hemoglobin and albumin, surgery duration, intraoperative blood loss, number of postoperative hospitalization days and expenses, readmission rates, and visual analog scale pain symptoms. Data were statistically evaluated using one-way analysis of variance with Student-Newman-Keuls-q post hoc tests or chi-square tests.
RESULTS: There were no significant differences in terms of age (P = 0.235), gender (P = 0.691), body mass index (P = 0.723), American Society of Anesthesiologists grade (0.747), lesion character (P = 0.337) and lesion site (P = 0.957) between the three groups. Within a 6 months follow-up period, there was no significant difference between the three groups in terms of surgery duration (P = 0.225), blood loss (P = 0.172), changes in hemoglobin (P = 0.255) and albumin (P = 0.178). However, postoperative hospitalization days (P = 0.000), postoperative costs (P = 0.019) and improvement of pain symptoms (P = 0.000) in ERAS group were significantly lower or higher than those in traditional group or ameliorated group, respectively. There were 29 (39.73%), 22 (31.43%), and 13 (20.00%), recorded cases of postoperative complications in traditional group, ameliorated group and ERAS group, respectively; complications in ERAS group were significantly lower than those in other two groups (P = 0.043). Moreover, all of the complications were mitigated effectively by the infusion of fluid, analgesia, treatment of infections, or antiemetic medications. There were 2 (2.74%), 3 (4.29%) and 2 (3.08%), recorded cases of re-admission in traditional group, ameliorated group and ERAS group, respectively, but there were no statistically significant differences when compared across the three groups (P = 0.866).
CONCLUSIONS: ERAS can provide benefits when it applied to patients undergoing ORD surgery mainly in terms of reducing postoperative complications, however, ERAS does not increase the economic burden of patients or decrease the risk of readmission.