Type II odontoid fractures in the elderly presenting to the emergency department: an assessment of factors affecting in-hospital mortality and discharge to skilled nursing facilities.

BACKGROUND CONTEXT: Type II odontoid fractures (OF) are among the most common cervical spine injuries in the geriatric population. However, there is a paucity of literature regarding their epidemiology. Additionally, the optimal management of these injuries remains controversial, and no study has evaluated the short-term outcomes of geriatric patients presenting to emergency departments (ED). PURPOSE: This study aims to document the epidemiology of geriatric patients presenting to EDs with type II OFs and determine whether surgical management was associated with early adverse outcomes such as in-hospital mortality and discharge to skilled nursing facilities (SNF). STUDY DESIGN: This is a retrospective cohort study. PATIENT SAMPLE: Data was used from the 2016-2020 Nationwide Emergency Department Sample. Patient encounters corresponding to type II OFs were identified. Patients younger than 65 at the time of presentation to the ED and those with concomitant spinal pathology were excluded. OUTCOME MEASURES: The association between the surgical management of geriatric type II OFs and outcomes such as in-hospital mortality and discharge to SNFs. METHODS: Patient, fracture, and surgical management characteristics were recorded. A propensity score matched cohort was constructed to reduce differences in age, comorbidities, and injury severity between patients undergoing operative and nonoperative management. Additionally, to develop a positive control for the analysis of geriatric patients with type II OFs and no other concomitant spinal pathology, a cohort of patients that had been excluded due to the presence of a concomitant spinal cord injury (SCI) was also constructed. Multivariate regressions were then performed on both the matched and unmatched cohorts to ascertain the associations between surgical treatment and in-hospital mortality, inpatient length of stay, encounter charges, and discharge to SNFs. RESULTS: A total of 11,325 encounters were included. The mean total charge per encounter was $60,221. 634 (5.6%) patients passed away during their encounters. In total, 1,005 (8.9%) patients were managed surgically. Surgical management of type II OFs was associated with a 316% increase in visit charge (95% CI: 291%-341%, p<.001), increased inpatient length of stay (IRR: 2.87, 95% CI: 2.62-3.12, p<.001), and increased likelihood of discharge to SNFs (OR=2.62, 95% CI: 2.26-3.05, p<.001), but decreased in-hospital mortality (OR=0.32, CI: 0.21-0.45, p<.001). The propensity score matched cohort consisted of 2,010 patients, matching each of the 1,005 that underwent surgery to 1,005 that did not. These cohorts were well balanced across age (78.24 vs 77.91 years), Elixhauser Comorbidity Index (3.68 vs 3.71), and Injury Severity Score (30.15 vs 28.93). This matching did not meaningfully alter the associations determined between surgical management and in-hospital mortality (OR=0.34, CI=0.21-0.55, p<.001) or SNF discharge (OR=2.59, CI=2.13-3.16, p<.001). Lastly, the positive control cohort of patients with concurrent SCI had higher rates of SNF discharge (50.0% vs 42.6%, p<.001), surgical management (32.3% vs 9.7%, p<.001), and in-hospital mortality (28.9% vs 5.6%, p<.001). CONCLUSIONS: This study lends insight into the epidemiology of geriatric type II OFs and quantifies risk factors influencing adverse outcomes. Patient informed consent should include a discussion of the protective association between definitive surgical management and in-hospital mortality against potential operative morbidity, increased lengths of hospital stay, and increased likelihood of discharge to SNFs. This information may impact patient treatment selection and decision making.

Biomechanical Assessment of Fracture Loads and Patterns of the Odontoid Process.

STUDY DESIGN: Laboratory study. OBJECTIVE: This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process. SUMMARY OF BACKGROUND DATA: Odontoid fractures of the second cervical vertebra (C2) represent the most common spine fracture type in the elderly. However, very little is known about the underlying biomechanical fracture mechanisms. MATERIALS AND METHODS: A total of 42 C2 human anatomic specimens were scanned via computed tomography, divided in six groups, and subjected to combined quasistatic loading at -15°, 0°, and 15° in sagittal plane and -50° and 0° in transverse plane until fracturing. Bone mineral density (BMD), height, fusion state of the ossification centers, stiffness, yield load, and ultimate load were assessed. RESULTS: While lowest values for stiffness, yield load, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences were observed between the study groups ( P ≥0.235). BMD correlated positively with yield load ( r2 =0.350, P <0.001) and ultimate load ( r2 =0.955, P <0.001) but not with stiffness ( r2 =0.082, P =0.07). The specimens with clearly distinguishable fusion of the ossification centers revealed less data scattering of the biomechanical outcomes. CONCLUSION: Load direction plays a subordinate role in traumatic fractures of the odontoid process. BMD was associated with significant correlation to the biomechanical outcomes. Thus, odontoid fractures appear to result from of an interaction between the load magnitude and bone quality.

A Nationwide Analysis of Geriatric Odontoid Fracture Incidence, Complications, Mortality, and Cost.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To identify nationwide temporal trends in management of geriatric odontoid fractures and to compare comorbidities, inpatient complications, hospital characteristics, and cost between patients receiving operative versus nonoperative management. SUMMARY OF BACKGROUND DATA: The treatment of geriatric odontoid fractures remains controversial with some studies demonstrating decreased mortality and improved functional outcomes associated with operative management and significant morbidity associated with halo devices during nonoperative management. METHODS: Patients between ages 65 to 90 years with odontoid fractures who underwent operative or nonoperative management between the years 2003 and 2017 were identified in the National Inpatient Sample (NIS) database. Year of injury, demographic variables, comorbidities, inpatient complications, mortality, length of stay, inpatient cost, and hospital characteristics were compared between operative and nonoperative treatment groups. RESULTS: Thirty two thousand four hundred nineteen patients (average age 77 yr, 54% female) were included in the final analysis. Operative treatment occurred in 21,954 (67%) patients and nonoperative treatment occurred in 10,465 (32%). In 2003, operative treatment occurred in 46% of patients and nearly doubled to 86% in 2017, with an average increase of 3.7% per year (P < 0.001). Patients undergoing operative management had a lower prevalence of at least one major medical comorbidity (76% vs. 83%, P < 0.001). Patients undergoing operative treatment demonstrated higher odds of developing most complications, particularly pulmonary, gastrointestinal, and renal (P < 0.01). Inpatient mortality was 3.6% in patients receiving operative treatment and 5.9% in patients receiving nonoperative treatment (P < 0.001). Average cost per episode of care during the study period was $131,855 for operative treatment and $65,374 for nonoperative treatment (P < 0.001). CONCLUSION: This study demonstrates a clear national paradigm shift in the management of geriatric odontoid fractures, wherein operative management nearly doubled from 46% in 2003 to 86% in 2017.Level of Evidence: 3.

Assessment of cervical range of motion in patients after axis fracture.

BACKGROUND: Surgical treatment of odontoid fractures with posterior C1/C2 fusion always leads to severe limitations in mobility of the cervical spine and head. PURPOSE: To assess the mobility of the cervical spine in patients treated with various surgical methods after an axis body fracture. MATERIAL AND METHODS: A group of 61 subjects receiving surgical treatment in a group of 214 subjects treated for odontoid fractures at one ward of neurosurgery at a regional hospital. Studies also included odontoid peg and Hangman fractures. The range of motion of the head was compared to standards by the International Standard Orthopedic Measurements (ISOM) and to head mobility in a control group of 80 healthy subjects without any pathologies or complaints associated with the cervical spine. Ranges of motion were measured with the CROM goniometre with regard to flexion, extension, right and left lateral flexion and right and left rotation. The functional status was evaluated with Neck Disability Index (NDI) standard questionnaires indicated for patients with cervical spine pain. RESULTS: Except for flexion and extension, patients after odontoid fractures had a statistically significantly smaller range of motion of the cervical spine in all planes compared to the control group and ISOM standards. CONCLUSIONS: Odontoid fractures lead to limitations in mobility of the cervical spine even after treatment with methods that in theory should preserve the C1/C2 mobility.

Cranio-vertebral transition assessment by magnetic resonance imaging in a sample of a northeast Brazilian population.

METHODS: Cross-sectional analysis of craniometric parameters from individuals submitted to magnetic resonance at an outpatient imaging center between 2011 and 2012. RESULTS: Of 181 analyzed cases, the Welcker basal angle averaged 128.96º (SD 6.51), median distance between apex of the odontoid and Chamberlain's line was 2.27 mm (IQR -1.23-4.47) and the median clivus-canal angle was 150.5º (IQR 143.2-157.3). The Welcker basal angle was inversely correlated to the clivus-canal angle, and correlated to the distance between the apex of the odontoid and Chamberlain's line. CONCLUSION: There was a tendency to platibasia, basilar invagination and narrowing of the cranio-vertebral transition.

Cranio-vertebral transition assessment by magnetic resonance imaging in a sample of a northeast Brazilian population / Avaliação da transição crânio-vertebral por ressonância magnética em uma amostra da população do nordeste brasileiro

ABSTRACT Platybasia and basilar invagination are important alterations of the cranial-vertebral transition. Neuroimaging-based platybasia parameters include the Welcker basal angle, distance between the apex of the odontoid and Chamberlain's line, and the clivus-canal angle. This study aimed to measure and correlate these parameters in a sample from northeast Brazil. Methods Cross-sectional analysis of craniometric parameters from individuals submitted to magnetic resonance at an outpatient imaging center between 2011 and 2012. Results Of 181 analyzed cases, the Welcker basal angle averaged 128.96º (SD 6.51), median distance between apex of the odontoid and Chamberlain's line was 2.27 mm (IQR -1.23-4.47) and the median clivus-canal angle was 150.5º (IQR 143.2-157.3). The Welcker basal angle was inversely correlated to the clivus-canal angle, and correlated to the distance between the apex of the odontoid and Chamberlain's line. Conclusion There was a tendency to platibasia, basilar invagination and narrowing of the cranio-vertebral transition.

RESUMO Platibasia e invaginação basilar são importantes alterações da transição craniovertebral. Existem parâmetros importantes obtidos pela neuroimagem, como o ângulo basal de Welcker, distância do ápice do odontoide à linha de Chamberlain e o ângulo clivo-canal. Este estudo procurou medir e correlacioná-los em uma amostra do Nordeste Brasileiro. Métodos Estudo transversal com medidas de indivíduos submetidos a ressonância magnética craniana em um centro de diagnóstico por imagem entre 2011 e 2012. Resultados Dos 181 casos analisados, o ângulo basal de Welcker teve média 128.96º (DP 6.51), a distância do ápice do odontoide à linha de Chamberlain obteve mediana 2.27 mm (IIQ -1.23-4.47) e o ângulo clivo-canal mediano foi 150.5º (IIQ 143.2-157.3). O ângulo basal de Welcker foi inversamente correlacionado com o ângulo clivo-canal e diretamente correlacionado com a distância do ápice do odontoide à linha de Chamberlain. Conclusão Houve uma tendência a platibasia, invaginação basilar e estreitamento da transição craniovertebral, que poderiam ser influenciados pela natureza multirracial e por fatores antropológicos da população estudada.

Cost Effectiveness of Operative Versus Non-Operative Treatment of Geriatric Type-II Odontoid Fracture.

STUDY DESIGN: Cost-effectiveness analysis. OBJECTIVE: To examine the cost-effectiveness of operative versus non-operative treatment of type-II odontoid fractures in patients older than 64 years old. SUMMARY OF BACKGROUND DATA: Significant controversy exists regarding the optimum treatment of geriatric patients with type-II odontoid fractures. Operative treatment leads to lower rates of non-union but carries surgical risks. Non-operative treatment does not carry surgical risks but has higher non-union rates. METHODS: A decision-analytic model was created to compare operative and non-operative treatment of type-II odontoid fractures among three age cohorts (65-74, 75-84, >84) based on expected costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs; cost per QALY gained). Age-specific mortality rates for both treatments, costs for treatment, and complication rates were taken from the literature, and data from 2010 US life tables were used for age-specific life expectancy. Costs of complications were estimated using data obtained at a level-I trauma center using micro-costing. Sensitivity analyses of all model parameters were conducted. RESULTS: Among the 65- to 74-year-old cohort, operative treatment was more costly ($53,407 vs. $30,553) and more effective (12.00 vs. 10.11 QALY), with an ICER of $12,078/QALY. Among the 75- to 84-year-old cohort, operative treatment was more costly ($51,308 vs. $29,789) and more effective (6.85 vs. 6.31 QALY), with an ICER of $40,467/QALY. Among the over-84 cohort, operative treatment was dominated by non-operative treatment as it was both more costly ($45,978 vs. $28,872) and less effective (2.48 vs. 3.73 QALY). The model was robust to sensitivity analysis across reasonable ranges for utility of union, disutility of complications and delayed surgery, and probabilities of non-union and complications. CONCLUSION: Operative treatment is cost-effective in patients age 65 to 84 when using $100,000/QALY as a benchmark but less effective and more costly than non-operative treatment in patients older than 84 years. LEVEL OF EVIDENCE: 2.

Craniocervical instability in the setting of os odontoideum: assessment of cause, presentation, and surgical outcomes in a series of 279 cases.

BACKGROUND: Our clinical understanding of os odontoideum (OO) remains incomplete. Congenital and traumatic causes have been proposed and advocated. Clinical presentations range from asymptomatic to axial pain to myelopathy or vertebral-basilar ischemia. A consensus for surgical management exists for those found to have an unstable atlantoaxial complex or symptomatic cranial-vertebral junction compression. OBJECTIVE: To evaluate the clinical presentation and surgical outcomes of patients with OO and an unstable atlantoaxial complex or symptomatic cranial-vertebral junction compression. METHODS: Patients with a diagnosis of OO who underwent surgical management were included. Patients were excluded on the basis of previous C2 fracture, Fielding diagnostic criteria, and inadequate follow-up. History of trauma and presenting symptoms were assessed. Clinical and neurological improvements were measured with the use of patient satisfaction scores and the Japanese Orthopaedic Association scores. Fusion status was documented with the use of radiographs and computed tomographic imaging. RESULTS: Of 279 patients, 112 reported a history of cranial-vertebral junction trauma, whereas 28 were diagnosed with congenital malformations. Clinically, 84.9% of patients presented with myelopathy, with pain presented in 42.6%. Atlantoaxial fixation was performed in 240 patients, occiput-to-C2 fixation in 35 patients, and extended occipito-cervical fixation in 4 patients. Mean follow-up was 40.3 months. Complications were reported in 2.4% of patients. Japanese Orthopaedic Association scores improved from a preoperative mean of 12.4 to 14.8. Two hundred thirty-five patients (77.7%) improved, with 30 patients experiencing no change in symptoms and 14 patients deteriorating. Fusion was achieved in 96.8% of patients. CONCLUSION: Our data reveal that surgical treatment for OO using the indications and techniques delineated is associated with high satisfaction rates, improved functional scores, and high fusion rates with low complication rates.

[Efficacy of halo-vest fixation in the assessment and prediction of the effectiveness of permanent fixation in a patient with basilar invagination with ambiguous vertebral instability].

Basilar invagination is a developmental anomaly of the craniovertebral junction in which the odontoid abnormally prolapses into the foramen magnum. It is also associated with Chiari malformation, syringomyelia, and hydrocephalus. Patients require surgical treatment to prevent progression of neurological symptoms, but assessment of anterior or posterior decompression can be difficult owing to bone instability and ambiguous compression of neural structures. Here, we describe a case of basilar invagination in a young adult. He presented with neurological symptoms, including syringomyelia, 3 months after a traffic trauma that might have led to instability of the bony structures. Since it was unclear whether the instability of the bony structures contributed to the clinical deterioration, the patient was first treated using halo-vest fixation. Significant improvements were observed in both neurological symptoms and magnetic resonance images. These results justified the invasive fixation and the patient was treated further with an occipito-cervical fusion ; good results were achieved in this case. Owing to the invasiveness of the procedure, occipito-cervical fixation should only be adopted following strict indication criteria. Halo-vest fixation was effective in treating the instability of the bony structures and as a trial treatment for permanent fixation.

Assessment of intrasubject reliability of radiographic craniocervical posture of asymptomatic female subjects.

OBJECTIVE: The objective of this study was to measure the reproducibility of the craniocervical posture (intrasubject reliability) of asymptomatic female subjects. METHODS: Two radiographs of the craniocervical posture of 22 female subjects (mean ± SD: age, 28 ± 4.37 years; body mass index, 22.3 ± 3.24 kg/m(2)) in the sagittal view were taken 1 week apart and at the same time of day. Their posture was standardized in the self-balance position. Seven angles were measured in the digitalized radiographs and analyzed using the Alcimage software (Uberlândia, Minas Gerais, Brazil). Intraclass correlation coefficient (ICC), SEM, and 95% confidence intervals were analyzed. RESULTS: Good-to-excellent ICC (ICC, 0.90-0.98) and small SEM (SEM, 0.25-0.70) were found. CONCLUSION: The craniocervical posture of the subjects included in this study was reproducible (ie, intrasubject reliability) when measured a week apart using radiographs.

A comparison of the Gallie technique and casting versus the harms technique for the treatment of odontoid fractures.

OBJECTIVE: The objective of this study was to compare perioperative, clinical parameters, complications, and reoperation rate of the Gallie technique and head-neck-chest plaster with the Harms technique in the treatment of odontoid fractures. DESIGN: A retrospective study. SETTING: Level I spine center. PATIENTS: Fifty-seven patients with odontoid fractures treated either with the Gallie technique and casting or the Harms technique between July 2002 and June 2008. INTERVENTION: Surgery. MAIN OUTCOME MEASUREMENTS: At a minimum of 2-year follow-up, comparison of the two groups was conducted in terms of hospital stay, blood loss, operation time, cost of the first admission, total cost, time to fusion, time to return to previous occupation, Japanese Orthopedic Association scores, visual analog scale scores of neck pain, complications (nonunion, delayed union, hardware breakage, wound infection), and reoperation rate. RESULTS: There were no significant differences in terms of hospital stay, time to fusion, Japanese Orthopedic Association scores, neck pain visual analog scale scores, complications, or reoperation rate between the two groups. Blood loss, operation time, cost of the first admission, and total cost were significantly lower in the Gallie group than that in the Harms group. However, the Gallie group took longer to return to previous occupation than the Harms group (P < 0.001). CONCLUSIONS: Management of odontoid fractures by either the Gallie technique and casting or the Harms technique was found to be similar in clinical outcomes. Although the Harms technique was associated with more blood loss, operation time, and cost, the Harms technique was found to be superior to the Gallie technique with casting in terms of time to return to previous occupation.

Trends in epidemiology and management of type II odontoid fractures: 20-year experience at a model system spine injury tertiary referral center.

STUDY DESIGN: A retrospective cohort study of consecutive type II Odontoid fractures presenting to a Level 1 Regional Model Systems Spinal Cord Injury Center between June 1985 and July 2006. OBJECTIVE: To assess trends in management of type II Odontoid fractures presenting to a Level 1 Model Systems Regional Spinal Cord Injury Center over a 20-year period. SUMMARY OF BACKGROUND DATA: Type II Odontoid fracture management is controversial, and a majority of studies have had relatively small cohorts. There is no consensus regarding definitive treatment, particularly in older patients. METHODS: Medical records of 263 consecutive type II Odontoid fractures from June 1985 to July 2006 were retrospectively reviewed. Patients were excluded if they had neurologic deficits, nonacute fracture, or ambiguous fracture classification. A cohort of 192 neurologically intact, acute type II odontoid fractures were identified. Admission records were reviewed for age, date of injury, date of admission, date of discharge, mechanism of injury, associated injuries, medical comorbidities, and radiologic findings. RESULTS: There was a statistically significant increase in the rate of presentation of type II odontoid fractures with time. The average age and medical comorbidities of the patient did not change over time. The probability of operative management markedly increased over time, corresponding to a statistically significant increase in length of hospital stay for patients undergoing surgery. The discharge disposition correlated significantly to both age of the patient and associated injuries. CONCLUSIONS: The number and frequency of type II odontoid fractures compared with other spine injuries seems to be increasing over the last 2 decades, which may be correlated with the increasing number of elderly persons in the population, given that referral patterns have been unchanged at our institution. Prospective outcomes data are needed to better elucidate optimal treatment algorithms from both, an outcomes and cost-efficacy perspective.

Study on accuracy and interobserver reliability of the assessment of odontoid fracture union using plain radiographs or CT scans.

In odontoid fracture research, outcome can be evaluated based on validated questionnaires, based on functional outcome in terms of atlantoaxial and total neck rotation, and based on the treatment-related union rate. Data on clinical and functional outcome are still sparse. In contrast, there is abundant information on union rates, although, frequently the rates differ widely. Odontoid union is the most frequently assessed outcome parameter and therefore it is imperative to investigate the interobserver reliability of fusion assessment using radiographs compared to CT scans. Our objective was to identify the diagnostic accuracy of plain radiographs in detecting union and nonunion after odontoid fractures and compare this to CT scans as the standard of reference. Complete sets of biplanar plain radiographs and CT scans of 21 patients treated for odontoid fractures were subjected to interobserver assessment of fusion. Image sets were presented to 18 international observers with a mean experience in fusion assessment of 10.7 years. Patients selected had complete radiographic follow-up at a mean of 63.3 +/- 53 months. Mean age of the patients at follow-up was 68.2 years. We calculated interobserver agreement of the diagnostic assessment using radiographs compared to using CT scans, as well as the sensitivity and specificity of the radiographic assessment. Agreement on the fusion status using radiographs compared to CT scans ranged between 62 and 90% depending on the observer. Concerning the assessment of non-union and fusion, the mean specificity was 62% and mean sensitivity was 77%. Statistical analysis revealed an agreement of 80-100% in 48% of cases only, between the biplanar radiographs and the reconstructed CT scans. In 50% of patients assessed there was an agreement of less than 80%. The mean sensitivity and specificity values indicate that radiographs are not a reliable measure to indicate odontoid fracture union or non-union. Regarding experience in years of all observers taking part in the study, there were no significant differences for specificity (P = 0.88) or sensitivity (P = 0.26). Further analysis revealed that if a non-union was judged present by an observer then, on average, each observer changed decision regarding the presence of a 'stable' or 'unstable non-union' in 4.2 of all the 21 cases (range 0-8 changes per observer). We investigated the interobserver reliability of the assessment of fusion in odontoid fractures using biplanar radiographs compared to CT scans. A sensitivity of 77% and a specificity of 62% for the radiographs resemble a substantial lack of agreement if different observers evaluate odontoid union. Biplanar radiographs are judged not a reliable measure to detect odontoid fracture union or non-union. The union rates of odontoid fractures have to be revisited and CT scans as the endpoint anchor in outcome studies of treatment related union rates are recommended.

Smear cytology in the intra-operative assessment of periodontoid pseudotumour of the craniocervical junction.

OBJECTIVE: Periodontoid pseudotumours are lesions of presumed degenerative aetiology which typically occur in elderly patients with cervical myelopathy. The clinical and radiological differential diagnosis includes neoplastic and inflammatory lesions, and the exclusion of such lesions may be of value in the intra-operative management of the patient. This audit aimed to examine the value of intra-operative smear cytology in the management of this condition. METHODS: The intra-operative smear cytological features of four cases of periodontoid pseudotumour were reviewed. RESULTS: In each case the intra-operative cytological interpretation was in keeping with a non-neoplastic and non-inflammatory process. CONCLUSION: These results suggest that intra-operative smear cytology can provide information on the value in the intra-operative management of patients with this lesion.

Atlantoaxial instability associated with an orthotopic os odontoideum: a multimodality imaging assessment.

Radiography, computed tomography (CT), and magnetic resonance imaging exams of the cervical spine were performed in a 29-year-old man who was ultimately diagnosed with an orthotopic os odontoideum during admission for injuries sustained in a motor vehicle collision. Initial radiography suggested either os odontoideum or an acute fracture of the dens. Further imaging with CT and flexion and extension radiographs confirmed os odontoideum and excluded a dens fracture. Although rare, os odontoideum is an important cervical spine anomaly to consider and to distinguish from an acute fracture of the dens.

An improved version of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth.

The present study aimed to provide a version of the Cervical Vertebral Maturation (CVM) method for the detection of the peak in mandibular growth based on the analysis of the second through fourth cervical vertebrae in a single cephalogram. The morphology of the bodies of the second (odontoid process, C2), third (C3), and fourth (C4) cervical vertebrae were analyzed in six consecutive cephalometric observations (T1 through T6) of 30 orthodontically untreated subjects. Observations for each subject consisted of two consecutive cephalograms comprising the interval of maximum mandibular growth (as assessed by means of the maximum increment in total mandibular length, Co-Gn), together with two earlier consecutive cephalograms and two later consecutive cephalograms. The analysis consisted of both visual and cephalometric appraisals of morphological characteristics of the three cervical vertebrae. The construction of the new version of the CVM method was based on the results of both ANOVA for repeated measures with post-hoc Scheffé's test (P < .05) and discriminant analysis. The new CVM method presents with five maturational stages (Cervical Vertebral Maturation Stage [CVMS] I through CVMS V, instead of Cvs 1 through Cvs 6 in the former CVM method). The peak in mandibular growth occurs between CVMS II and CVMS III, and it has not been reached without the attainment of both CVMS I and CVMS II. CVMS V is recorded at least two years after the peak. The advantages of the new version of the CVM method are that mandibular skeletal maturity can be appraised on a single cephalogram and through the analysis of only the second, third, and fourth cervical vertebrae, which usually are visible even when a protective radiation collar is worn.

MRI assessment of the alar ligaments in the late stage of whiplash injury--a study of structural abnormalities and observer agreement.

Our aim was to characterise and classify structural changes in the alar ligaments in the late stage of whiplash injuries by use of a new MRI protocol, and to evaluate the reliability and the validity of this classification. We studied 92 whiplash-injured and 30 uninjured individuals who underwent proton density-weighted MRI of the craniovertebral junction in three orthogonal planes. Changes in the alar ligaments (grades 0-3) based on the ratio between the high signal area and the total cross-sectional area were rated twice at a 4-month interval, independently by three radiologists. Inter- and intraobserver statistics were calculated by ordinary and weighted kappa. Cases classified differently were reviewed to identify potential causes for disagreement. The alar ligaments were satisfactorily demonstrated in all cases (244 ligaments in 122 individuals). The lesions, 2-9 years after the injury, varied from small high-signal spots to high signal throughout the cross-sectional area. Signal was highest near the condylar insertion in 82 of 94 ligaments, indicating a lesion near that insertion, and near the dental insertion in eight, indicating a medial lesion. No grade 2 or 3 lesion was found in the control group. At least two observers assigned the same grade to 214 ligaments (87.7%) on the second occasion. In 30 ligaments (12.3%) this agreement was not obtained. Pair-wise interobserver agreement (weighted kappa) was fair to moderate (0.31-0.54) in the first grading, improving to moderate (0.49-0.57) in the second. Intraobserver agreement (weighted kappa) was moderate to good (0.43-0.70). Whiplash trauma can cause permanent damage to the alar ligaments, which can be shown by high-resolution proton density-weighted MRI. Reliability of classification of alar ligament lesions needs to be improved.

[Instability of the atlantodental joint as a trauma sequela]. / Zur Frage der Instabilität des atlantodentalen Gelenks als Traumafolge.

In the region of the upper cervical spine a wide variety of morphological and functional positions is possible. This makes diagnosis and expert evaluation of whiplash injuries to the cervical spine very difficult. The problem is discussed with reference to a case report of a so-called whiplash injury. The upper cervical spine must be investigated in flexion and extension by means of MRT and/or CT as soon as possible.