Management and Outcome of Dens Fracture Nonunions in Geriatric Patients

Comparison of intraoperative CT- and cone beam CT-based spinal navigation for the treatment of atlantoaxial instability

BACKGROUND CONTEXT

Due to the complexity of neurovascular structures in the atlantoaxial region, spinal navigation for posterior C1-C2 instrumentation is nowadays a helpful tool to increase accuracy of surgery and safety of patients. Many available intraoperative navigation devices have proven their reliability in this part of the spine. Two main imaging techniques are used: intraoperative CT (iCT) and cone beam computed tomography (CBCT).

PURPOSE

Comparison of iCT- and CBCT-based technologies for navigated posterior instrumentation in C1-C2 instability.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

A total of 81 consecutive patients from July 2014 to April 2020.

OUTCOME MEASURES

Screw accuracy and operating time.

METHODS

Patients with C1-C2 instability received posterior instrumentation using C2 pedicle screws, C1 lateral mass or pedicle screws. All screws were inserted using intraoperative imaging either using iCT or CBCT systems and spinal navigation with autoregistration technology. Following navigated screw insertion, a second intraoperative scan was performed to assess the accuracy of screw placement. Accuracy was defined as the percentage of correctly placed screws or with minor cortical breach (<2 mm) as graded by an independent observer compared to misplaced screws.

RESULTS

A total of 81 patients with C1-C2 instability were retrospectively analyzed. Of these, 34 patients were operated with the use of iCT and 47 with CBCT. No significant demographic difference was found between groups. In the iCT group, 97.7% of the C1-C2 screws were correctly inserted; 2.3% showed a minor cortical breach (<2 mm); no misplacement (>2 mm). In the CBCT group, 98.9% of screws were correctly inserted; no minor pedicle breach; 1.1% showed misplacement >2 mm. Accuracy of screw placement demonstrated no significant difference between groups. Both technologies allowed sufficient identification of screw misplacement intraoperatively leading to two screw revisions in the iCT and three in the CBCT group. Median time of surgery was significantly shorter using CBCT technology (166.5 minutes [iCT] vs 122 minutes [CBCT]; p<.01).

CONCLUSIONS

Spinal navigation using either iCT- or CBCT-based systems with autoregistration allows safe and reliable screw placement and intraoperative assessment of screw positioning. Using the herein presented procedural protocols, CBCT systems allow shorter operating time.

Multicenter retrospective cohort study of the association between surgery for odontoid fractures in the elderly and in-hospital outcomes

Odontoid fractures are increasingly prevalent in older adults and associated with high morbidity and mortality. Optimal management remains controversial. Our study aims to investigate the association between surgical management of odontoid fractures and in-hospital mortality in a multi-center geriatric cohort. We identified patients 65 years or older with C2 odontoid fractures from the Trauma Quality Improvement Program database. The primary study outcome was in-hospital mortality. Secondary outcomes were in-hospital complications and hospital length of stay. Generalized estimating equation models were used to compare outcomes between operative and non-operative cohorts. Among the 13,218 eligible patients, 1100 (8.3%) were treated surgically. The risk of in-hospital mortality did not differ between surgical and non-surgical groups, after patient and hospital-level adjustment (OR: 0.94, 95%CI: 0.55-1.60). The risks of major complications and immobility-related complications were higher in the operative cohort (adjusted OR: 2.12, 95%CI: 1.53-2.94; and OR: 2.24, 95%CI: 1.38-3.63, respectively). Patients undergoing surgery had extended in-hospital length of stay compared to the non-operative group (9 days, IQR: 6-12 days vs. 4 days, IQR: 3-7 days). These findings were supported by secondary analyses that considered between-center differences in rates of surgery. Among geriatric patients with odontoid fractures surgical management was associated with similar in-hospital mortality, but higher in-hospital complication rates compared to non-operative management. Surgical management of geriatric patients with odontoid fractures requires careful patient selection and consideration of pre-existing comorbidities.

A Predictive Model to Identify Treatment-related Risk Factors for Odontoid Fracture Nonunion Using Machine Learning

STUDY DESIGN

Multicenter retrospective analysis of routinely collected data.

OBJECTIVE

The underlying aim of this study was to identify potential treatment-related risk factors for odontoid fracture nonunion while accounting for known patient- and injury-related risk factors.

SUMMARY OF BACKGROUND DATA

Type II and III odontoid fractures represent the most common cervical spine fracture in elderly patients and are associated with a relatively high nonunion rate. The management of odontoid fractures is controversial and treatment strategies range from conservative treatment to extensive surgical stabilization and fusion.

METHODS

A total of 415 individuals who sustained odontoid fracture and were treated in either of four tertiary referral centers in Austria and Germany were included in the study. We included the following potential contributing factors for fracture nonunion in cross-validated extreme gradient boosted (XGBoost) and binary logistic regression models: age, gender, fracture displacement, mechanism of injury (high vs. low energy), fracture classification (Anderson II vs. III), presence of comorbidities (Charlson comorbidity index), and treatment (conservative, anterior screw fixation with one or two screws, posterior C1/C2 spondylodesis, cervico-occipital C0-C4 fusion).

RESULTS

In our cohort, 187 (45%) had radiologically confirmed odontoid nonunion six months postinjury. The odds for nonunion increase significantly with age, and are lower in type III compared to type II fractures. Also, odds for nonunion are significantly lower in posterior C1/C2 spondylodesis, and C0-C4 fusion compared to conservative treatment. Importantly, odds are not statistically significantly lower in the group treated with anterior screw fixation compared to conservative treatment. The factors gender, fracture displacement, mechanism of injury, and the presence of comorbidities did not produce significant odds.

CONCLUSION

Higher age, type II fractures, and conservative treatment are the main risk factors for odontoid nonunion. Anterior screw fixation did not differ significantly from conservative treatment in terms of fracture union.

LEVEL OF EVIDENCE

3.

Reevaluation of a classification system: stable and unstable odontoid fractures in geriatric patients-a radiological outcome measurement

Objectives

We carried out a retrospective cohort study to differentiate geriatric odontoid fractures into stable and unstable and correlated it with fracture fusion rates. Results are based on the literature and on our own experience. The authors propose that the simple Anderson and D’Alonzo classification may not be sufficient for geriatric patients.

Methods

There were 89 patients ≥ 65 years who presented at our institution with type II and III odontoid fractures from 2003 until 2017 and were included in this study. Each patient was categorized with CT scans to evaluate the type of fracture, fracture gap (mm), fracture angulation (°), fracture displacement (mm) and direction (ventral, dorsal). Fractures were categorized as stable [SF] or unstable [UF] distinguished by the parameters of its angulation (< / > 11°) and displacement (< / > 5 mm) with a follow-up time of 6 months.

SFs were treated with a semi-rigid immobilization for 6 weeks, UFs surgically—preferably with a C1–C2 posterior fusion.

Results

The classification into SFs and UFs was significant for its angulation (P = 0.0006) and displacement (P < 0.0001). SF group (n = 57): A primary stable union was observed in 35, a stable non-union in 10, and an unstable non-union in 8 patients of which 4 were treated with a C1/2 fixation. The overall consolidation rate was 79%. UF group (n = 32): A posterior C1–C2 fusion was carried out in 23 patients, a C0 onto C4 stabilization in 7 and an anterior odontoid screw fixation in 2. The union rate was 100%. Twenty-one type II SFs (91%) consolidated with a nonoperative management (P < 0.001). A primary non-union occurred more often in type II than in type III fractures (P = 0.0023). There was no significant difference in the 30-day overall case fatality (P = 0.3786).

Conclusion

To separate dens fractures into SFs and UFs is feasible. For SFs, semi-rigid immobilization provides a high consolidation rate. Stable non-unions are acceptable, and the authors suggest a posterior transarticular C1–C2 fixation as the preferred surgical treatment for UFs.

Level of evidence

Level III.

Odontoid Type II fractures in elderly: what are the real management goals and how to best achieve them? A multicenter European study on functional outcome

Odontoid fractures constitute the most common cervical fractures in elderly. External immobilization is the treatment of choice for Type I and III; there is still no wide consensus about the best management of Type II fractures. Observational multicenter study was conducted on a prospectively built database on elderly patients (> 75 years) with Type II odontoid fracture managed conservatively during the last 10 years. All patients underwent CT scan on admission and at 3 months; if indicated, selected patient had CT scan at 6 and 12 months. All patients were clinically evaluated by Neck Disability Index (NDI), Charlson Comorbidity Index (CCI), and American Society of Anaesthesiologists classification (ASA) on admission; NDI was assessed also at 6 weeks, 3, 6, 12, and 24 months; furthermore, a quality of life (QoL) assessment with the SF-12 form was performed at 3 and 12 months. Among the 260 patients enrolled, 177 (68%) were women and 83 (32%) men, with a median age of 83 years. Patients were followed up for a minimum of 24 months: 247 (95%) showed an excellent functional outcome within 6 weeks, among them 117 (45%) showed a good bony healing, whereas 130 (50%) healed in pseudo-arthrosis. The residual 5% were still variably symptomatic at 12 weeks; however, only 5 out of 13 (2% of the total cohort) required delayed surgery. This study showed that a conservative approach to odontoid Type II fracture in elderly is an effective and valid option, resulting in an excellent functional outcome (regardless of bony fusion) in the majority of cases. Failure of conservative treatment can be safely addressed with surgical fixation at a later stage.

Odontoid fractures: impact of age and comorbidities on surgical decision making

Background

Surgical fixation is recommended for type II and III odontoid fractures (OFx) with major translation of the odontoid fragment, regardless of the patient’s age, and for all type II OFx in patients aged ≥50 years. The level of compliance with this recommendation is unknown, and our hypothesis is that open surgical fixation is less frequently performed than recommended. We suspect that this discrepancy might be due to the older age and comorbidities among patients with OFx.

Methods

We present a prospective observational cohort study of all patients in the southeastern Norwegian population (3.0 million) diagnosed with a traumatic OFx in the period from 2015 to 2018.

Results

Three hundred thirty-six patients with an OFx were diagnosed, resulting in an overall incidence of 2.8/100000 persons/year. The median age of the patients was 80 years, and 45% were females. According to the Anderson and D’Alonzo classification, the OFx were type II in 199 patients (59%) and type III in 137 patients (41%). The primary fracture treatment was rigid collar alone in 79% of patients and open surgical fixation in 21%. In the multivariate analysis, the following parameters were significantly associated with surgery as the primary treatment: independent living, less serious comorbidities prior to the injury, type II OFx and major sagittal translation of the odontoid fragment. Conversion from external immobilization alone to subsequent open surgical fixation was performed in 10% of patients. Significant differences the in conversion rate were not observed between patients with type II and III fractures. The level of compliance with the treatment recommendations for OFx was low. The main deviation was the underuse of primary surgical fixation for type II OFx. The most common reasons listed for choosing primary external immobilization instead of primary surgical fixation were an older age and comorbidities.

Conclusion

Major comorbidities and an older age appear to be significant factors contributing to physicians’ decision to refrain from the surgical fixation of OFx. Hence, comorbidities and age should be considered for inclusion in the decision tree for the choice of treatment for OFx in future guidelines.

Functional Outcome After Odontoid Fractures in the Elderly

While several papers on mortality and the fusion rate in elderly patients treated surgically or non-surgically for odontoid fractures exist, little information is available on quality of life after treatment. The aim of treatment in these patients should not be fracture healing alone but also quality of life improvement.A literature search using PubMed identified seven papers including information on functional evaluation of 402 patients.Patients treated with anterior screw fixation had a good functional outcome in 92.6% of cases. This percentage seemed to decrease in octogenarians. Less information was available for patients treated with posterior approaches; it would seem that up to a half of such patients experienced pain and limitations in activities of daily living after surgery. Patients treated with a halo device had a functional outcome that was worse (or at least no better) than that of patients treated with surgery, with absence of limitations in activities of daily living in 77.3% of patients. Patients treated with a collar had a good functional outcome in the majority of cases, with absence of limitations in activities of daily living in 89% of patients.More studies are needed for evaluation of functional outcome, especially in patients treated with a collar, a halo device or a posterior approach.

Independent Correlation of the C1-2 Cobb Angle With Patient-Reported Outcomes After Correcting Chronic Atlantoaxial Instability

Objective

To investigate three-planar radiographic results and patient-reported outcomes (PROs) after correcting chronic atlantoaxial instability (AAI) by translaminar screw (TLS) and pedicle screw (PS) fixation, and to explore the potential association of atlantoaxial realignment with PRO improvements.

Methods

Twenty-three patients who underwent C1 lateral mass screw (LMS)-C2 TLS and 29 who underwent C1 LMS-C2 PS with ≥ 2 years of follow-up were retrospectively analyzed. Three-planar (sagittal, coronal, and axial) radiographic parameters were measured. PROs including the Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) score and the Short Form 36 Physical Component Summary (SF-36 PCS) were documented. Factors potentially associated with PROs were identified.

Results

The radiographic parameters significantly changed postoperatively except the C1–2 midlines’ intersection angle in the TLS group (p = 0.073) and posterior atlanto-dens interval in both groups (p = 0.283, p = 0.271, respectively). The difference in bilateral odontoid lateral mass interspaces at last follow-up was better corrected in the TLS group than in the PS group (p = 0.010). Postoperative PROs had significantly improved in both groups (all p < 0.05). Thereinto, NDI at last follow-up was significantly lower in the TLS group compared with PS group (p = 0.013). In addition, blood loss and operative time were obviously lesser in TLS group compared with PS group (p = 0.010, p = 0.004, respectively). Multivariable regression analysis revealed that a change in C1–2 Cobb angle was independently correlated to PROs improvement (NDI: β = -0.435, p = 0.003; JOA score: β = 0.111, p = 0.033; SF-36 PCS: β = 1.013, p = 0.024, respectively), also age ≤ 40 years was independently associated with NDI (β = 5.40, p = 0.002).

Conclusion

Three-planar AAI should be reconstructed by C1 LMS-C2 PS fixation, while sagittal or coronal AAI could be corrected by C1 LMS-C2 TLS fixation. PROs may improve after atlantoaxial reconstruction in patients with chronic AAI. The C1–2 Cobb angle is an independent predictor of PROs after correcting chronic AAI, as is age ≤ 40 years for postoperative NDI.

Functional Outcome of Elderly Patients Treated for Odontoid Fracture: A Multicenter Study

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVE

Analysis of impact of conservative and surgical treatments on functional outcome of geriatric odontoid fractures.

SUMMARY OF BACKGROUND DATA

Treatment of odontoid fractures in aged population is still debatable.

METHODS

One hundred fourty-seven consecutive odontoid fractures in elderly patients were classified according to Anderson-D'Alonzo and Roy-Camille classifications. Philadelphia type collar was always positioned and kept as a treatment whenever acceptable. Halo-vest, anterior screw fixation, C1-C2 posterior arthrodesis, and occipito-cervical fixation were the other treatments adopted. Conservative or surgical treatment strategy was more significantly influenced by antero-posterior displacement (< or >5 mm) and by surgeon decision. On admission ASA, modified Rankin scale (mRS-pre) and Charlson Comorbidity Index (CCI) were assessed. Modified Rankin scale (mRS-post), Neck Disability Index (NDI), and Smiley Webster Pain Scale (SWPS) were administered 12 to 15 months after treatment to estimate functional outcome in terms of general disability, neck-related disability, and ability to return to work/former activity. Risk of treatment crossover was calculated considering factors affecting outcome. Fracture healing process in terms of fusion-stability, no fusion-stability, no fusion-no stability was evaluated at 12 months through a cervical computed tomography (CT) scan. Dynamic cervical spine x-rays were obtained whether necessary. No fusion-stability was considered an adequate treatment goal in our geriatric population. Chi square/Fisher exact test and logistic regression were performed for statistical anal.

RESULTS

Overall 67 patients were treated conservatively whereas 80 underwent surgery. Collar was adopted in 45 patients, while anterior odontoid fixation and C1-C2 posterior arthrodesis were preferred for 30 patients each. 79.8% of patients showed good outcomes according to NDI. No significant differences were observed between patients of 65 to 79 years and more than or equal to 80 years (P = 0.81). CCI greatly correlated with mRS-post, with higher indexes in 68.8% of cases characterized by good outcomes (P = 0.05). mRS-pre correlated with NDI (P < 0.000001) and mRS-post (P = 0.04). CCI, mRS-pre, and surgery were associated with worse NDI, while both C1-C2 posterior arthrodesis and occipito-cervical stabilization were associated with worse mRS-post, respectively in 40% and 30% of cases. Younger patients had a higher risk of treatment crossover.

CONCLUSION

mRS-pre and CCI provided two independent predictive values respectively for functional outcome and post-treatment disability. Compared with conservative immobilizations, surgery revealed no advantages in the elderly in terms of functional outcome.

LEVEL OF EVIDENCE

3.

Type II odontoid fracture in elderly patients treated conservatively: is fracture healing the goal?

PURPOSE

Analysis of functional outcome of elderly patients with type II odontoid fractures treated conservatively in relation to their radiological outcome.

METHODS

A total of 50 geriatric patients with type II odontoid fractures were treated with Aspen/Vista collars. On admission, each patient was assessed assigning ASA score, modified Rankin Scale (mRS-pre) and Charlson Comorbidity Index (CCI). From 12-15 months after treatment, functional evaluations were performed employing a second modified Rankin Scale (mRS-post) together with Neck Disability Index (NDI) and Smiley-Webster pain scale (SWPS). Radiological outcome was evaluated through dynamic cervical spine X-rays at 3 months and cervical spine CT scans 6 months after treatment. Three different conditions were identified: stable union, stable non-union and unstable non-union. Surgery was preferred whenever a fracture gap > 2 mm, an antero-posterior displacement > 5 mm, an odontoid angulation > 11° or neurological deficits occurred.

RESULTS

Among the 50 patients, 24 reached a stable union, while 26 a stable non-union. Comparing the two groups, no differences in ASA (p = 0.60), CCI (p = 0.85) and mRS-pre (p = 0.14) were noted. Similarly, no differences in mRS-post (p = 0.96), SWPS (p = 0.85) and NDI (p = 0.51) were observed between patients who reached an osseous fusion and those with a stable fibrous non-union. No effects of age, sex, ASA, mRS-pre, fracture dislocation and radiological outcome were discovered on functional outcome. At logistic regression analysis, female sex and high values of CCI emerged associated with worse NDI.

CONCLUSIONS

In geriatric type II odontoid fractures, pre-injury clinical status and comorbidities overcome imaging in determining post-treatment level of function. Hard collar immobilization led to a favourable functional outcome with mRS-post, NDI and SWPS values diffusely encouraging whatever a bony union or a fibrous non-union was obtained. These slides can be retrieved under Electronic Supplementary Material.

Mortality, complication, and fusion rates of patients with odontoid fracture: the impact of age and comorbidities in 204 cases

PURPOSE

The French Society of Spine Surgery (SFCR) conducted a prospective epidemiologic multicenter study. The purpose was to investigate mortality, complication, and fusion rates in patients with odontoid fracture, depending on age, comorbidities, fracture type, and treatment.

METHODS

Out of 204 patients, 60 were ≤ 70 years and 144 were > 70 years. Demographic data, comorbidities, treatment types and complications (general medical, infectious, neurologic, and mechanical), and death were registered within the first year. Fractures were classified according to Anderson-D'Alonzo and Roy-Camille on the initial CT. A 1-year follow-up CT was available in 144 patients to evaluate fracture consolidation.

RESULTS

Type II and oblique-posterior fractures were the most frequent patterns. The treatment was conservative in 52.5% and surgical in 47.5%. The mortality rate in patients ≤ 70 was 3.3% and 16.7% in patients > 70 years (p = 0.0002). Fracture pattern and treatment type did not influence mortality. General medical complications were significantly more frequent > 70 years (p = 0.021) and after surgical treatment (p = 0.028). Neurologic complications occurred in 0.5%, postoperative infections in 2.0%, and implant-related mechanical complications in 10.3% (associated with pseudarthrosis). Fracture fusion was observed in 93.5% of patients ≤ 70 years and in 62.5% >70 years (p < 0.0001). Pseudarthrosis was present in 31.5% of oblique-posterior fractures and in 24.3% after conservative treatment.

CONCLUSIONS

Age and comorbidities influenced mortality and medical complication rates most regardless of fracture type and treatment choice. Pseudarthrosis represented the main complication, which increased with age. Pseudarthrosis was most frequent in type II and oblique-posterior fractures after conservative treatment.

Predictors of 30-Day Outcomes in Octogenarians with Traumatic C2 Fractures Undergoing Surgery

BACKGROUND

Predictors of surgical outcomes following traumatic axis (C2) fractures in octogenarians remain undercharacterized.

METHODS

Patients age ≥80 years undergoing cervical spine surgery following traumatic C2 fractures were extracted from the National Sample Program of the National Trauma Data Bank (2003-2012). Outcomes include overall inpatient complications, individual complications with an incidence >1%, hospital length of stay (HLOS), discharge disposition, and mortality. Demographics, comorbidities, and injury predictors were analyzed using multivariable regression. Odds ratios (OR), mean differences, and 95% confidence intervals (CIs) were calculated. Statistical significance was assessed at P < 0.05.

RESULTS

The cohort of 442 patients was 48.6% male and had a mean age of 84.3 ± 2.7 years. The distribution of admissions was 42.3% to the hospital floor, 40.3% to the intensive care unit (ICU), 7.7% to telemetry, 2.0% to the operating room, and 7.7% to other/unknown. Mortality was 9.7%, mean HLOS was 13.1 ± 9.2 days, the rate of complications was 38.5%, and 81.5% of survivors were discharged to a nonhome facility. Injury severity was predictive of mortality and overall complications. History of bleeding disorder/coagulopathy predicted mortality (OR, 4.02; 95% CI, 1.07-15.05), overall complications (OR, 3.01; 95% CI, 1.09-8.32), cardiac arrest (OR, 8.19; 95% CI, 1.06-63.54), and renal complications (OR, 10.36; 95% CI, 2.13-50.38). History of congestive heart failure predicted mortality (OR, 3.10; 95% CI, 1.10-8.69). ICU admission (vs. floor) predicted overall complications (OR, 2.01; 95% CI, 1.23-3.27) and pneumonia (OR, 4.65; 95% CI, 1.91-11.30). Telemetry admission (vs. floor) predicted unplanned intubation (OR, 7.76; 95% CI, 1.24-48.49).

CONCLUSIONS

In this cohort of octogenarians undergoing surgery for traumatic C2 fracture, injury severity and a history of bleeding disorder/coagulopathy were identified as risk factors for inpatient complications and mortality. Heightened surveillance should be considered for ICU and/or telemetry admissions for the development of complications. These findings warrant consideration by the clinician, patient, and family to inform clinical decisions and goals of care.

Management of Odontoid Fractures in the Elderly: A Review of the Literature and an Evidence-Based Treatment Algorithm

Odontoid fractures are the most common fracture of the axis and the most common cervical spine fracture in patients over 65. Despite their frequency, there is considerable ambiguity regarding optimal management strategies for these fractures in the elderly. Poor bone health and medical comorbidities contribute to increased surgical risk in this population; however, nonoperative management is associated with a risk of nonunion or fibrous union. We provide a review of the existing literature and discuss the classification and evaluation of odontoid fractures. The merits of operative vs nonoperative management, fibrous union, and the choice of operative approach in elderly patients are discussed. A treatment algorithm is presented based on the available literature. We believe that type I and type III odontoid fractures can be managed in a collar in most cases. Type II fractures with any additonal risk factors for nonunion (displacement, comminution, etc) should be considered for surgical management. However, the risks of surgery in an elderly population must be carefully considered on a case-by-case basis. In a frail elderly patient, a fibrous nonunion with close follow-up is an acceptable outcome. If operative management is chosen, a posterior approach is should be chosen when fracture- or patient-related factors make an anterior approach challenging. The high levels of morbidity and mortality associated with odontoid fractures should encourage all providers to pursue medical co-management and optimization of bone health following diagnosis.

Anterior endoscopically assisted bone grafting for iatrogenic distraction of odontoid fracture after percutaneous anterior screw fixation: A case report

RATIONALE

The complication of iatrogenic distraction of odontoid fracture after anterior screw fixation has not been reported in the literature. We treated the patient with endoscopically assisted bone grafting with good results. The new technique was not reported in the management of odontoid fracture or nonunion before.

PATIENT CONCERNS

A 22-year-old man presented with neck pain after a motorcycle crash. The cervical spine radiograph and computed tomographic scan demonstrated the base of dens displaced 2 mm anteriorly.

DIAGNOSES

Radiographic images showed a type II odontoid fracture.

INTERVENTIONS

The patient was treated by percutaneous anterior screw fixation. The postoperative radiograph and CT demonstrated an iatrogenic distraction of the odontoid with a gap of 6 mm.The follow-up radiograph did not show any sign of bone union 1 month and a half later. A revision surgery was given by anterior endoscopically assisted bone grafting. The patient was encouraged to sit out of bed immediately after the surgery with the protection of a soft cervical collar for 3 months.

OUTCOMES

No complications such as neural structures or vascular injuries were found. Bone union was achieved at the 1-year follow-up CT scans. Physical examination showed a full range of motion in the neck.

LESSONS

We reported a case of iatrogenic odontoid distraction that was managed by anterior endoscopically assisted bone grafting. It is a technically feasible and minimally invasive procedure.

Predisposing Factors of Fracture Nonunion After Posterior C1 Lateral Mass Screws Combined with C2 Pedicle/Laminar Screw Fixation for Type II Odontoid Fracture

INTRODUCTION

The aim of this study was to explore the predisposing factors for fracture nonunion after a lateral screw was combined with C2 pedicle/laminar screw for a type II odontoid fracture and hopefully provide references in decision making and surgical planning for spinal surgeons.

METHODS

This is a retrospective study. By retrieving the medical records from January 2010 to July 2015 in our hospital, 117 type II odontoid fracture patients were reviewed. According to the occurrence of fracture union at the final follow-up, patients were divided into 2 groups: union and nonunion. To investigate the predisposing factors for fracture nonunion, 3 categorized factors were analyzed statistically: patient characteristics-age, sex, body mass index, preoperative Japanese Orthopaedic Association (JOA) scores, duration, comorbidity, and complicated injuries; surgical variables-surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2; radiographic parameters-preoperative and immediate postoperative data of C_0-2 curvature, C_2-7 curvature, C_2-7 sagittal vertical axis, C7 slope, fracture classification, congenital hypoplastic vertebral artery, and the separation and displacement of the odontoid fracture. Other variables including JOA and visual analog scale scores for neck pain, neck stiffness, and patient satisfaction at final follow-up were recorded and compared between the 2 groups.

RESULTS

Postoperative fracture nonunion was detected in 76 of 117 patients (65%) at final follow-up. There was no statistically significant difference between the 2 groups in patient characteristics of sex, body mass index, JOA score, comorbidity, and complicated injuries. The mean age at operation was younger in the union group than in the nonunion group, and the mean duration was shorter in the union group than in the nonunion group. There was no difference in surgical variables of surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2. There was no difference in radiographic parameters of fracture classification, congenital hypoplastic vertebral artery, preoperative and immediate postoperative C_0-2 curvature, C_2-7 curvature, C_2-7 SVA, and C7 slope. No difference was found in preoperative and immediate postoperative displacement of the odontoid fracture or immediate postoperative separation of the odontoid fracture, while the preoperative separation of the odontoid fracture was shorter in the union group than in the nonunion group. The logistic regression analysis revealed that advanced age (>45 years), long duration (>2 months), and preoperative separation of the odontoid fracture (>4 mm) were independently associated with the postoperative fracture nonunion. There were no differences between the 2 groups in JOA, neck pain, neck stiffness, and patient satisfaction at final follow-up.

CONCLUSIONS

Advanced age, long duration, and preoperative separation of odontoid fracture >4 mm are predisposing factors for fracture nonunion after posterior C1 lateral screw combined with C2 pedicle/laminar screw fixation for type II odontoid fracture. Our findings did not demonstrate any evidence of lower functional outcome and patients satisfaction for those patients who had odontoid nonunion.

Controversies in the Management of Geriatric Odontoid Fractures

Fractures of the odontoid process of C2 have become increasingly prevalent in the aging population and are typically associated with a high incidence of morbidity. Dens fractures comprise the majority of all cervical fractures in patients older than 80 years and remain the most common cervical fracture pattern in all geriatric patients. Type II odontoid fractures have been associated with limited healing potential, and both nonoperative and operative management are associated with high mortality rates. Historically, there has been some debate in the literature with regards to optimal management strategies to maximize outcomes in geriatric patients. Recent, high-quality evidence has indicated that surgical treatment of type II odontoid fractures in elderly patients is associated with improvements in both short- and long-term mortality. Additionally, surgical intervention has been shown to improve functional outcomes when compared with nonsurgical treatment. Factors to consider before surgery for geriatric type II odontoid fractures include associated comorbidities and the safety of general anesthesia administration. With appropriate measures of patient selection, surgery can provide an efficacious option for geriatric patients with type II odontoid fractures. We recommend surgical intervention via a posterior C1-C2 arthrodesis for geriatric type II odontoid fractures, provided that the surgery itself does not represent an unreasonable risk for mortality.

Odontoid Fracture in a Patient With Diffuse Idiopathic Skeletal Hyperostosis

Nonoperative management of fractures in the setting of diffuse idiopathic skeletal hyperostosis (DISH) or ankylosing spondylitis is often unsuccessful. The subaxial spine is a common site of hyperextension fractures in the setting of DISH. Fractures of the upper cervical spine are uncommon in DISH. We report, to our knowledge, the first case describing successful nonoperative management of a type 2 odontoid fracture in a patient with DISH. We discuss the patient’s initial presentation, physical examination, imaging findings, and management. A 73-year-old male presented with neck pain to the emergency department after sustaining a ground-level fall. Computed tomography of the cervical spine demonstrated a minimally displaced type 2 odontoid fracture in the setting of extensive DISH. He was immobilized with a hard cervical collar as the definitive management of his fracture. The collar was discontinued after 3 months. At his 2-year follow-up, he had a stable fibrous nonunion at the fracture site with tolerable neck pain. Flexion–extension radiographs demonstrated a stable alignment, and nonoperative management was continued. In selected patients with odontoid fractures in the setting of DISH, there is a role for nonoperative management alongside close monitoring.