Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries

Evolution of Patient-Reported Outcome Measures, 1, 2, and 5 years after Surgery for Subaxial Cervical Spine Fractures, A Nation-Wide Registry Study

BACKGROUND CONTEXT

A longer duration of patient follow-up arguably provides more reliable data on the long-term effects of a treatment. However, the collection of long-term follow-up data is resource demanding and often complicated by missing data and patients being lost to follow-up. In surgical fixation for cervical spine fractures, data are lacking on the evolution of patient reported outcome measures (PROMs) beyond 1-year of follow-up. We hypothesized that the PROMs would remain stable beyond the 1-year postoperative follow-up mark, regardless of the surgical approach.

PURPOSE

To assess the trends in the evolution of patient-reported outcome measures (PROMs) at 1, 2-, and 5-years following surgery in patients with traumatic cervical spine injuries.

STUDY DESIGN

Nation-wide observational study on prospectively collected data.

PATIENT SAMPLE

Individuals treated for subaxial cervical spine fractures with anterior, posterior, or combined anteroposterior approaches, between 2006 and 2016 were identified in the Swedish Spine Registry (Swespine).

OUTCOME MEASURES

PROMs consisting of EQ-5D-3L_index and the Neck Disability Index (NDI) were considered.

METHODS

PROMs data were available for 292 patients at 1 and 2 years postoperatively. Five-years PROMs data were available for 142 of these patients. A simultaneous within-group (longitudinal) and between group (approach-dependent) analysis was performed using mixed ANOVA. The predictive ability of 1-year PROMs was subsequently assessed using linear regression.

RESULTS

Mixed ANOVA revealed that PROMs remained stable from 1- to 2-years as well as from 2- to 5-years postoperatively and were not affected by the surgical approach (p<0.05). A strong correlation was found between 1-year and both 2- and 5-years PROMs (R>0.7; p<0.001). Linear regression confirmed the accuracy of 1-year PROMs in predicting both 2- and 5-years PROMs (p<0.001).

CONCLUSION

PROMs remained stable beyond 1-year of follow-up in patients treated with anterior, posterior, or combined anteroposterior surgeries for subaxial cervical spine fractures. The 1-year PROMs were strong predictors of PROMs measured at 2, and 5 years. The 1-year PROMs were sufficient to assess the outcomes of subaxial cervical fixation irrespective of the surgical approach.

Clinical and surgical results related to anterior-only multilevel cervical decompression and instrumented fusion for degenerative disease

Introduction

Anterior-only multilevel cervical decompression and fusion surgery (AMCS) on 3-5-levels is challenging due to potential complications. Also, outcome predictors after AMCS are poorly understood.

Research Question

We hypothesize that in patients with at most mild/moderate cervical kyphosis (CK) of the cervical spine, restoration of cervical lordosis (CL) positively influences clinical outcomes.

Methods

Analysis of consecutive patients presenting with symptomatic degenerative cervical disease or non-union undergoing AMCS. We measured CL from C2 to C7, Cobb angle of fused levels (fusion angle, FA), C7-Slope, and sagittal vertical axis C2-7 (cSVA, stratified into ≤4cm∖>4cm). Patients with excellent outcome were grouped in BEST-outcomes and with moderate/poor outcomes in WORST-outcomes.

Results

We included 244 patients. Fifty-four percent had 3-, 39% 4-level and 7% had 5-level fusion. At mean follow-up of 26 months, 41% of patients achieved BEST-outcome and 23% WORST-outcome. Complications and reoperation rates did not significantly differ. Non-union significantly influenced outcomes. The number of patients with non-union was significantly higher in patients with a preoperative cSVA>4cm (OR 13.1 (95%CI:1.8-96.8). Our model, based on the multivariable analysis with WORST-outcome as outcome variable showed a high accuracy (NPV=73%, PPV=77%, specificity=79%, sensitivity=71%).

Discussion and Conclusion

In 3-5-level AMCS, improvement of FA and cSVA were independent predictors of clinical outcome. Improvement of CL positively influenced clinical outcomes and rates of non-union.

Quality of Life in Adult Patients Receiving Cervical Fusion for Fresh Subaxial Cervical Injury: The Role of Associated Spinal Cord Injury

Purpose

To study postoperative Health-Related Quality of Life (HRQOL) after instrumented fusion for fresh subaxial cervical trauma and the effect of spinal cord injury (SCI).

Methods

From a total of 65 patients, 17 (26%) patients suffered on admission from SCI. Twenty-five patients underwent anterior, 25 posterior, and 15 circumferential cervical surgery for a single cervical injury. Sagittal roentgenographic parameters were measured in 65 age-matched asymptomatic controls and in patients on admission, eight months postoperatively and at final follow-up (lower C₂-C₇ curvature, cervical sagittal vertical axis (cSVA), spinocranial angle (SCA), T₁-slope, neck tilt (NT), thorax inlet angle (TIA), cervical tilt (CT), cranial tilt (CrT), and occiput–C₂ angle (C₀-C₂)). In the last evaluation, SCI patients were compared with their counterparts without SCI using national validated HRQOL instruments (SF-36 and neck disability index (NDI)).

Results

Fusion included an average of 3 vertebrae (range 2-4 vertebrae). All 65 patients were followed for an average of 5.5 years, (range 3-7 years) postoperatively. In the last evaluation, 10 (15.4%) patients with incomplete SCI improved postoperatively at 1-2 grades. At the last observation, patients with SCI showed poorer HRQOL scores than their counterparts without SCI. In particular, each SF-36 domain score was correlated with SCA, T₁-slope, cSVA, and CT. At baseline, patients showed higher NT, CrT, and C0-C2 angle than controls. Eight months postoperatively, cSVA, NT, TIA, and cranial tilt (CrT) were increased in patients. In the last observation, there was difference in the sagittal roentgenographic parameters between patients with SCI compared to those without SCI. Patients aged ≥55 years had postoperatively increased cSVA, NT, and CrT compared to their younger counterparts.

Conclusion

At the final observation, HRQOL scores were lower in patients with SCI than in their non-SCI counterparts, obviously because of the associated neurologic impairment. SF-36 scores correlated with several sagittal roentgenographic parameters. These correlations should be taken in consideration by spine surgeons when performing cervical spine surgery for fresh cervical spine injuries.

A biomechanical analysis of four anterior cervical techniques to treating multilevel cervical spondylotic myelopathy: a finite element study

BACKGROUND

The decision to treat multilevel cervical spondylotic myelopathy (MCSM) remains controversial. The purpose of this study is to compare the biomechanical characteristics of the intervertebral discs at the adjacent segments and internal fixation, and to provide scientific experimental evidence for surgical treatment of MCSM.

METHODS

An intact C2-C7 cervical spine model was developed and validated. Four additional models were developed from the fusion model, including multilevel anterior cervical discectomy and fusion (mACDF), anterior cervical corpectomy and fusion (ACCF), hybrid decompression and fusion (HDF), and mACDF with cage alone (mACDF-CA). Biomechanical characteristics on the plate and the disc of adjacent levels (C2/3, C6/7) were comparatively analyzed.

RESULTS

Of the four models, stress on the upper (C2/3) adjacent intervertebral disc was the lowest in the mACDF-CA group and highest in the ACCF group. Stress on the intervertebral discs at adjacent segments was higher for the upper C2/3 than the lower C6/7 intervertebral disc. In all models, the mACDF-CA group had the lowest stress on the intervertebral disc, while the ACCF group had the highest stress. In the three surgical models with titanium plate fixation (mACDF, ACCF, and HDF), the ACCF group had the highest stress at the titanium plate-screw interface, while the mACDF group had the lowest stress.

CONCLUSION

Among the four anterior cervical reconstructive techniques for MCSM, mACDF-CA makes little effect on the adjacent disc stress, which might reduce the incidence of adjacent segment degeneration (ASD) after fusion. However, the accompanying risk of the increased incidence of cage subsidence should never be neglected.

Subaxial Cervical Spine Injuries: Outcomes after Anterior Corpectomy and Instrumentation

Study Design

This is prospective study.

Purpose

The purpose of this study is to assess the functional, neurological, and radiological outcomes of the patients of subaxial cervical spine injuries treated by anterior corpectomy and stabilization with anterior cervical locking plate and cage filled with bone.

Overview of the Literature

The principles in the treatment of unstable cervical spine injuries are reduction and stabilization of the injured segment, maintenance of cervical lordosis and decompression where indicated and ranges from nonoperative to combined anterior and posterior surgical fusion. There is, however, debate on the indications for anterior, posterior, or combined surgery.

Materials and Methods

The present study of 99 patients includes prospective patients of subaxial cervical spine injuries between February 2014 and February 2016 admitted and operated to Indira Gandhi Medical College, Shimla. Bony fusion, neurological recovery, Neck Disability Index and complication were studied in all patients. The mean follow-up period was 27 months (range 12-42 months).

Results

Of the 99 procedures, 77 (77.8%) involved a single vertebral level, 19 (19.2%) involved two levels, and 3 (3%) involved three levels corpectomy. The mean Neck Disability Index was 7.57 ± 5.42. Definitive Bridwell Grade 1 fusion was seen in 64.6% of the cases. No deterioration of neurological symptoms was seen. Dysphagia was the most common complication in 79 (79.8%) patients. One patient had minimal screw back out.

Conclusions

Anterior cervical corpectomy and stabilization with cage filled with bone and cervical reflex locking plate are good method for subaxial cervical spine injuries with good fusion rates and probably procedure of choice for posttraumatic multiple disc prolapse with reduced hazards of multiple grafts.

Is there an impact of cervical plating on the development of adjacent segment degeneration following Smith-Robinson procedure? A magnetic resonance imaging study of 84 patients with a 24-year follow-up

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) without and with cervical plating (ACDF+CP) are accepted surgical techniques for the treatment of degenerative cervical disc disorders. The effect of CP on the development of adjacent segment degeneration (ASD) remains unclear.

PURPOSE

To assess whether CP accelerates the degeneration of the adjacent and adjoining segments.

STUDY DESIGN/SETTING

This is an imaging cohort study.

PATIENT SAMPLE

Retrospectively, a total of 84 patients who underwent ACDF or ACDF+CP were identified. At final follow-up, an MRI was performed and evaluated in this study.

MATERIALS AND METHODS

An MRI of 84 patients who underwent ACDF (46 patients) and ACDF+PS (38 patients) was performed. The mean follow-up was 24 years (17-45 years). None of the patients had a repeat procedure in the cervical spine. The grade of degeneration of the segments adjacent and adjoining to the fusion was assessed via a five-step grading system (segmental degeneration index, or SDI) that includes disc signal intensity, anterior and posterior disc protrusion, narrowing of the disc space, and foraminal stenosis. Furthermore, the disc height (DH) and sagittal segmental angle (SSA) of fused segments were measured.

RESULTS

A significantly (p<.001) greater SDI was identified at the caudal adjacent segment following ACDF compared to ACDF+CP. No other significant differences were identified in patients following ACDF and ACDF+CP. Between 50% and 96% of all segments showed severe degenerative changes according to SDI. There was no significant difference in DH between the patients following ACDF and ACDF+CP. The SSA in patients who underwent ACDF+CP was significantly greater than in the ACDF patients (p=.002).

CONCLUSIONS

In this cohort of patients, cervical plating had no significant impact on segmental degeneration and decrease of DH in the adjacent and adjoining segments. ACDF+CP seem to preserve the lordotic alignment more with respect to the SSA than ACDF.

Early ventral surgical treatment without traction of acute traumatic subaxial cervical spine injuries

Background:

Spinal cord decompression after cervical spinal cord injury (SCI) is the standard of care. However, there is a lack of consensus regarding the optimal management of these injuries, including the role of traction and timing of surgery. Here, we report the safety/efficacy of ventral surgery without preoperative traction for intraoperative fracture reduction following acute cervical SCI.

Methods:

We prospectively collected a series of patients who sustained acute traumatic subaxial cervical (C3–7) spine fractures between 2004 and 2016. Patients underwent anterior cervical decompression and fusion within 24 h of injury without the utilization of preoperative traction.

Results:

Thirty-six patients (27 male, 9 female), averaging 35 years of age, sustained 25 motor-vehicle accidents, 4 sports-related injuries, and 7 falls. Fracture dislocations were seen in 26 patients, whereas burst fractures were seen in 10. The majority of injuries occurred at the C4–5 (13 patients) and C5–6 (13 patients) levels. Complete SCI occurred in 10 patients, and incomplete SCI in 26 patients. All patients underwent anterior surgery only; 16 required vertebrectomy in addition to anterior cervical discectomy and fusion. Intraoperative reduction was achieved in all patients using a Cobb elevator or distraction pins without the use of preanesthesia traction. There were no intraoperative complications. Postoperatively, there were one postoperative hematoma, two wound/hardware revisions, one subsequent posterior fusion, and one reoperation anteriorly after screw pullout. The average hospital length of stay was 10.6 days (range 1–39).

Conclusion:

Early direct surgical stabilization/fusion for acute SCI because of subaxial cervical spine fractures is both safe and effective in selected cases when performed anteriorly without preoperative traction in select cases.

Functional Outcomes of Subaxial Spine Injuries Managed With 2-Level Anterior Cervical Corpectomy and Fusion: A Prospective Study

Objective

To evaluate the results of operative management of subaxial spine injuries managed with 2-level anterior cervical corpectomy and fusion with a cervical locking plate and autologous bone–filled titanium mesh cage.

Methods

This study included 23 patients with a subaxial spine injury who matched the inclusion criteria, underwent 2-level anterior cervical corpectomy and fusion at our institution between 2013 and 2016, and were followed up for neurological recovery, axial pain, fusion, pseudarthrosis, and implant failure.

Results

According to Allen and Ferguson classification, there were 9 cases of distractive extension; 4 of compressive extension; 3 each of compressive flexion, vertical compression, and distractive flexion; and 1 of lateral flexion. Sixteen patients had a score of 6 on the Subaxial Injury Classification system, and the rest had a score of more than 6. The mean follow-up period was 19 months (range, 12–48 months). Neurological recovery was observed in most of the patients (78.21%). All patients experienced relief of axial pain. None of the patients received a blood transfusion. Twenty-one patients (91.3%) showed solid fusion and 2 (8.69%) showed possible pseudarthrosis, with no complications related to the cage or plate.

Conclusion

Two-level anterior cervical corpectomy and fusion, along with stabilization with a cervical locking plate and autologous bone graft-filled titanium mesh cage, can be considered a feasible and safe method for treating specific subaxial spine injuries, with the benefits of high primary stability, anatomical reduction, and direct decompression of the spinal cord.

Biomechanics of anterior plating failure in treating distractive flexion injury in the caudal subaxial cervical spine

BACKGROUND

Operative level is a potential biomechanical risk factor for construct failure during anterior fixation for distractive flexion injury. No biomechanical study of this concept has been reported, although it is important in clinical management.

METHODS

To explore the mechanism of this concept, a previously validated three-dimensional C2-T1 finite element model was modified to simulate surgical procedure via the anterior approach for treating single-level distractive flexion injury, from C2-C3 to C7-T1. Four loading conditions were used including no-compression, follower load, axial load, and combined load. Construct stability at the operative level was assessed.

FINDINGS

Under these loading conditions with the head's weight simulated, segmental stability decreases when the operative level shifts cephalocaudally, especially at C6-C7 and C7-T1, the stress of screw-bone interface increases cephalocaudally, and in the same operative level, the caudal screws always carries more load than the cephalad ones. All these predicted results are consistent with failure patterns observed in clinical reports. In the contrast, under other loading conditions without the weight of head, no obvious segmental divergence was predicted.

INTERPRETATION

This study supports that the biomechanical mechanism of this phenomenon includes eccentric load from head weight during sagittal movements and difference of moment arms. Our study suggests that anterior fixation is not recommended for treating distractive flexion injury at the caudal segments of the subaxial cervical spine, especially at C6-C7 and C7-T1, because of the intrinsic instability in these segments. Combined posterior rigid fixation with anterior fixation should be considered for these segments.

Anterior cervical distraction and screw elevating-pulling reduction for traumatic cervical spine fractures and dislocations: A retrospective analysis of 86 cases

Treatment of cervical fracture and dislocation by improving the anterior cervical technique.Anterior cervical approach has been extensively used in treating cervical spine fractures and dislocations. However, when this approach is used in the treatment of locked facet joints, an unsatisfactory intraoperative reduction and prying reduction increases the risk of secondary spinal cord injury. Thus, herein, the cervical anterior approach was improved. With distractor and screw elevation therapy during surgery, the restoration rate is increased, and secondary injury to the spinal cord is avoided.To discuss the feasibility of the surgical method of treating traumatic cervical spine fractures and dislocations and the clinical application.This retrospective study included the duration of patients' hospitalization from January 2005 to June 2015. The potential risks of surgery (including death and other surgical complications) were explained clearly, and written consents were obtained from all patients before surgery.The study was conducted on 86 patients (54 males and 32 females, average age of 40.1 ± 5.6 years) with traumatic cervical spine fractures and dislocations, who underwent one-stage anterior approach treatment. The effective methods were evaluated by postoperative follow-up.The healing of the surgical incision was monitored in 86 patients. The follow-up duration was 18 to 36 (average 26.4 ± 7.1) months. The patients achieved bones grafted fusion and restored spine stability in 3 to 9 (average 6) months after the surgery. Statistically, significant improvement was observed by Frankel score, visual analog scale score, Japanese Orthopedic Association score, and correction rate of the cervical spine dislocation pre- and postoperative (P < .01).The modified anterior cervical approach is simple with a low risk but a good effect in reduction. In addition, it can reduce the risk of iatrogenic secondary spinal cord injury and maintain optimal cervical spine stability as observed during follow-ups. Therefore, it is suitable for clinical promotion and application.

Adjacent Segment Pathology after Anterior Cervical Fusion

Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion.

Preliminary Analysis of Adjacent Segment Degeneration in Patients Treated with Posterior Cervical Cages: 2-Year Follow-Up

OBJECTIVE

Select patients with unremitting symptoms of cervical radiculopathy may be treated with indirect foraminal decompression and fusion via placement of a cervical cage placed bilaterally through a tissue sparing, posterior approach. Segmental fusion is known to affect adjacent segments. The aim of this study was to assess the affect of posterior fusion using bilateral cervical cages on adjacent segment degeneration (ASDegeneration) at 2 years postoperatively.

METHODS

Fifty-three patients enrolled in a prospective multicenter study who completed the imaging protocol were available for follow-up at 2 years. Lateral cervical radiographs were acquired preoperatively and at 1- and 2-years postoperatively. Imaging was evaluated for adjacent level degeneration using the following criteria: disk height ratio (DHR) defined as the ratio of the disk height and the lower vertebrae height measured at level above and below; proximal junctional kyphosis (PJK); Kellgren and Lawrence osteoarthritis severity grade (KLOSG); and heterotopic ossification (HO). The results were compared with a repeated analysis of variance test and Bonferroni correction; P < 0.05 was considered significant.

RESULTS

At 2 years postoperatively, there were no revision surgeries at the operated level or new surgeries at the adjacent levels. Of the 102 segments evaluated, ASDegeneration was identified at 21 levels cranial to and 21 levels caudal to the index level. At 2 years, new mild ASDegeneration signs developed at 3 levels: 1 in the level above and 2 in the level below the operated segment. In patients with pre-existing disk degeneration, mild progression of ASDegeneration signs developed in 6 upper and 2 lower segments. There were no significant changes in DHR and PJK in all patients; however, when patients with signs of ASDegeneration only were evaluated, a significant decrease of the DHR was found. The mean DHRs before surgery and 1 and 2 years after surgery in all patients were 44.0 ± 8.1, 44.0 ± 8.2, and 43.1 ± 8.4 (P = 0.1006) and in ASD patients were 43.8 ± 7.3, 41.9 ± 6.3, and 39.6 ± 8.3 (P = 0.0062), respectively. Overall, at 2 years postoperatively, ASDegeneration was identified in 9 patients (17.6% when compared with all evaluated patients before surgery).

CONCLUSIONS

In the current study, 5.9% of subjects treated with posterior cervical cages placed bilaterally between the facet joints developed adjacent segment degeneration at 2 years. Mild progression of existing degeneration was observed in 11.8% of subjects. Further evaluation to establish long-term incidence is needed.

Longer plate-to-disc distance prevents adjacent-level ossification development but does not influence adjacent-segment degeneration

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To clarify the association between plate-to-disc distance (PDD) and adjacent-level ossification development (ALOD) and adjacent segment degeneration (ASD).

SUMMARY OF BACKGROUND DATA

Anterior cervical discectomy and fusion with plating provides higher fusion rate and improved alignment but has been reported to result in ALOD and ASD.

METHODS

We retrospectively reviewed 218 patients with solid fusion after anterior cervical arthrodesis with plating at our institution between January 2004 and December 2010. PDD was measured on postoperative lateral radiographs for each adjacent disc space and used to assign patients to 1 of 3 groups: group L, long PDD (>5 mm); group S, short PDD (0 mm ≤PDD ≤5 mm); and group N, PDD (<0 mm, disk space encroachment). Mean follow-up was 5.3 years. Incidences of cranial and caudal ALOD and ASD with and without symptoms were compared among groups. Severity of caudal ossification was not measured in 30 patients because bony overlap precluded adequate visualization of the caudal level.

RESULTS

Ossification developed in 134 (61%) of 218 cranial adjacent disc spaces and 45 (24%) of 188 caudal adjacent disc spaces (P < 0.01). Mean cranial PDD was shorter than mean caudal PDD (P < 0.01). Ossification rate was higher in group N than in group S at the cranial adjacent disc spaces (100% vs. 66%, P < 0.01). Incidences of both cranial and caudal ALOD were significantly higher in group S than in group L (66% vs. 31%, P < 0.01; and 31% vs. 13%, P < 0.01, respectively). No significant differences in symptomatic and asymptomatic ASD were seen among groups.

CONCLUSION

Longer PDD does not decrease the incidence of ASD but it can prevent ALOD. We now attempt to place anterior cervical plates of 5 mm or greater from adjacent disc spaces.

LEVEL OF EVIDENCE

3.

Anterior surgical treatment of cervical spondylotic myelopathy: review article

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a common indication for cervical spine surgery. Surgical options include anterior, posterior, or combined procedures each with specific advantages and disadvantages.

QUESTIONS/PURPOSES

This article will provide a description of the various anterior alternatives and discuss the available evidence used in guiding the surgical decision making process with the aim of answering the following questions: (1) What anatomical/disease related factors favor anterior over posterior surgeries? (2) What are the common anterior procedures and how safe and effective are they? (3) What are the most effective options for multilevel CSM? (4) Is there a role for motion preservation? An additional objective is to discuss technical advances that have improved success rates for anterior procedures.

METHODS

The PubMed database was searched. Keywords were CSM and anterior surgery. Three hundred eighty two articles were found one hundred three were reviewed. Articles describing anterior cervical techniques were selected along with studies describing the various anterior techniques or comparisons of anterior to posterior techniques.

RESULTS

Anterior decompression and fusion procedures are more effective than posterior procedures for patients with primarily ventrally located compression especially in the presence of cervical kyphosis. ACDF, ACCF, and hybrid combinations are safe and effective treatment options for multilevel CSM. Anterior procedures may be more cost effective and result in significantly improved postoperative quality of life and health-related quality of life measures compared to posterior procedures.

CONCLUSION

Anterior cervical decompression techniques are safe and effective in the treatment of CSM. Anterior surgeries may be preferable to posterior approaches, when considering health-related quality of life measures and cost effectiveness.

In vitro biomechanical evaluation of four fixation techniques for distractive-flexion injury stage 3 of the cervical spine

PURPOSE

Anterior plate fixation has been reported to provide satisfactory results in cervical spine distractive flexion (DF) injuries stages 1 and 2, but will result in a substantial failure rate in more unstable stage 3 and above. The aim of this investigation was to determine the biomechanical properties of different fixation techniques in a DF-3 injury model where all structures responsible for the posterior tension band mechanism are torn.

METHODS

The multidirectional three-dimensional stiffness of the subaxial cervical spine was measured in eight cadaveric specimens with a simulated DF-3 injury at C5-C6, stabilized with four different fixation techniques: anterior plate alone, anterior plate combined with posterior wire, transarticular facet screws, and a pedicle screw-rod construct, respectively.

RESULTS

The anterior plate alone did not improve stability compared to the intact spine condition, thus allowing considerable range of motion around all three cardinal axes (p > 0.05). The anterior plate combined with posterior wire technique improved flexion-extension stiffness (p = 0.023), but not in axial rotation and lateral bending. When the anterior plate was combined with transarticular facet screws or with a pedicle screws-rod instrumentation, the stability improved in flexion-extension, lateral bending, and in axial rotation (p < 0.05).

CONCLUSIONS

These findings imply that the use of anterior fixation alone is insufficient for fixation of the highly unstable DF-3 injury. In these situations, the use of anterior fixation combined with a competent posterior tension band reconstruction (e.g. transarticular screws or a posterior pedicle screws-rod device) improves segmental stability.

Health-related quality-of-life outcomes after thoracic (T1-T10) fractures

BACKGROUND CONTEXT

The thoracic spine exhibits a unique response to trauma as the result of recognized anatomical and biomechanical differences. Despite this response, clinical studies often group thoracic fractures (T1-T10) with more caudal thoracolumbar injuries. Subsequently, there is a paucity of literature on the functional outcomes of this distinct group of injuries.

PURPOSE

To describe and identify predictors of health-related quality-of-life outcomes and re-employment status in patients with thoracic fractures who present to a spine injury tertiary referral center.

STUDY DESIGN

An ambispective cohort study with cross-sectional outcome assessment.

PATIENT SAMPLE

A prospectively collected fully relational spine database was searched to identify all adult (>16 years) patients treated with traumatic thoracic (T1-T10) fractures with and without neurologic deficits, treated between 1995 and 2008.

OUTCOME MEASURES

The Short-Form-36, Oswestry Disability Index, and Prolo Economic Scale outcome instruments were completed at a minimum follow-up of 12 months. Preoperative and minimum 1-year postinjury X-rays were evaluated.

METHOD

Univariate and multivariate regression analysis was used to identify predictors of outcomes from a range of demographic, injury, treatment, and radiographic variables.

RESULTS

One hundred twenty-six patients, age 36±15 years (mean±SD), with 135 fractures were assessed at a mean follow-up of 6 years (range 1-15.5 years). Traffic accidents (45%) and translational injuries (54%) were the most common mechanism and dominant fracture pattern, respectively. Neurologic deficits were frequent-53% had complete (American Spinal Injury Association impairment scale [AIS] A) spinal cord deficits on admission. Operative management was performed in 78%. Patients who sustain thoracic fractures, but escaped significant neurologic injury (AIS D or E on admission) had SF-36 scores that did not differ significantly from population norms at a mean follow-up of 6 years. Eighty-eight percent of this cohort was re-employed. Interestingly, Oswestry Disability Index scores remained inferior to healthy subjects. In contrast, SF-36 scores in those with more profound neurologic deficits at presentation (AIS A, B, or C) remained inferior to normative data. Fifty-seven percent were re-employed, 25% in their previous job type. Using multiple regression analysis, we found that comorbidity status (measured by the Charlson Comorbidity index) was the only independent predictor of SF-36 scores. Neurologic impairment (AIS) and adverse events were independent predictors of the SF-36 physical functioning subscale. Sagittal alignment and number of fused levels were not independent predictors.

CONCLUSIONS

At a mean follow-up of 6 years, patients who presented with thoracic fractures and AIS D or E neurologic status recovered a general health status not significantly inferior to population norms. Compared with other neurologic intact spinal injuries, patients with thoracic injuries have a favorable generic health-related quality-of-life prognosis. Inferior outcomes and re-employment prospects were noted in those with more significant neurologic deficits.

Post-traumatic lower cervical spine instability: arthrodesis clinical and radiological outcomes at 5 years

BACKGROUND

Anterior cervical fusion is widely used to treat spinal injuries. Radiological evidence of disc abnormalities may develop on either side of the fused segment, raising concern about the potential for inducing adjacent-segment disease. Here, we report the long-term clinical, functional, and radiological outcomes after anterior cervical fusion.

HYPOTHESIS

Anterior cervical fusion influences the development of adjacent-segment disease.

MATERIALS AND METHODS

In a retrospective study, 15 patients aged 17 to 50 years were re-evaluated more than 5 years after anterior spinal fusion to treat post-traumatic cervical-spine instability. We used the Neck Disability Index (NDI) to assess function. Static and dynamic radiographs of the cervical spine were obtained.

RESULTS

NDI values indicated good clinical and functional outcomes, and fusion was achieved consistently. Adjacent-segment disease was a consistent finding at last follow-up but induced no neurological manifestations. Complete fusion of a level adjacent to the treated level was noted in 2 patients. Revision surgery for adjacent-segment disease was not required in any patient.

CONCLUSION

The causative factors of adjacent-segment disease are controversial. Disc degeneration is a normal manifestation of the ageing process. Nevertheless, disc disease is more prevalent at levels adjacent to interbody fusion than in the normal population, suggesting accelerated disc degeneration due to increased loading of the adjacent levels. Furthermore, lesions that are missed during the pre-operative work-up may play a role, as the available investigations do not always have high negative predictive values.

LEVEL OF EVIDENCE

Level IV, retrospective study.

The Subaxial Cervical Spine Injury Classification System: an external agreement validation study

BACKGROUND CONTEXT

In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study.

PURPOSE

To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC treatment algorithm outcome improved agreement on treatment decisions among surgeons.

STUDY DESIGN

An external classification validation study.

PATIENT SAMPLE

Twelve spinal surgeons (five consultants and seven fellows) assessed 51 randomly selected cases.

OUTCOME MEASURES

Raw agreement, Fleiss kappa, and intraclass correlation coefficient statistics were used for reliability analysis. Majority rules and latent class modeling were used for accuracy analysis.

METHODS

Fifty-one randomly selected cases with significant injuries of the cervical spine from a prospective consecutive series of trauma patients were assessed using the SLIC system. Neurologic details, plain radiographs, and computed tomography scans were available for all cases as well as magnetic resonance imaging in 21 cases (41%). No funds were received in support of this study. The authors have no conflict of interest in the subject of this article.

RESULTS

The inter-rater agreement on the most severely affected level of injury was strong (κ=0.76). The agreement on the morphologic injury characteristics was poor (κ=0.29) and agreement on the integrity of the discoligamentous complex was average (κ=0.46). The inter-rater agreement on the treatment verdict after the total SLIC injury severity score was slightly lower than the surgeons' agreement on personal treatment preference (κ=0.55 vs. κ=0.63). Latent class analysis was not converging and did not present accurate estimations of the true classification categories. Based on these findings, no second survey for testing intrarater agreement was performed.

CONCLUSIONS

We found poor agreement on the morphologic injury characteristics of the SLIC system, and its treatment algorithm showed no improved agreement on treatment decisions among surgeons. The authors discuss that the reproducibility of the SLIC system is likely to improve when unambiguous true morphologic injury characteristics are being implemented.

Indication for spinal fusion and the risk of adjacent segment pathology: does reason for fusion affect risk? A systematic review

STUDY DESIGN

A systematic review.

OBJECTIVE

To determine whether different indications or reasons for spinal fusion are associated with different risks of subsequent adjacent segment pathology (ASP) in the lumbar and cervical spine.

SUMMARY OF BACKGROUND DATA

Pre-existing degeneration at levels adjacent to an arthrodesis may play a role in the development of symptomatic adjacent segment pathology. Although most spinal arthrodeses occur in patients with degenerative spinal disease, spinal fusion occurs in the pediatric and trauma population, and also congenitally. Evaluating the risk of ASP in these populations may shed light on its etiology.

METHODS

A systematic search was conducted in PubMed and the Cochrane Library for articles published between January 1, 1990, and December 31, 2011. We included all articles that described the risk of radiographical adjacent segment pathology (RASP) following surgical fusion for degenerative disease, for trauma, or for conditions requiring fusion in pediatrics in the lumbar or cervical spine. In addition, we included studies recording ASP in patients with congenital fusion.

RESULTS

Nineteen studies met our inclusion criteria. In patients who underwent fusion in the lumbar spine for degenerative reasons, the RASP rate averaged 12.4% during an average of 5.6-year follow-up. For patients who underwent fusion in the cervical spine for degenerative reasons, the average RASP rate was 25.3% during a 2.3-year follow-up. For patients with Klippel-Feil syndrome and congenital fusion, the RASP rate averaged 49.7% during an average of 23.5-years of follow-up. In patients who were fused for scoliosis, the average RASP rate was 20.3% of 3.9-year follow-up. However there is significant variation between studies in patient population, follow-up, and definition of RASP.

CONCLUSION

In the cervical spine, the rate of RASP in patients with fusion for degenerative reasons indications is greater than the rate of RASP in patients with congenital fusion suggesting that the pre-existing health and status of the adjacent level at the time of fusion may play a contributory role in the development of ASP. There is insufficient evidence in the literature to determine whether the indication/reason for fusion affects the risk of RASP in the lumbar spine

CONSENSUS STATEMENT

In the cervical spine, the rate of RASP in patients with fusion for degenerative reasons indications is greater than the rate of RASP in patients with congenital fusion suggesting that the pre-existing health and status of the adjacent level at the time of fusion may play a contributory role in the development of ASP. Strength of Statement: Weak.

Cervical pedicle screw fixation in traumatic cervical subluxation after laminectomy using the pedicle axis view technique under fluoroscopy

Cervical pedicle screw (CPS) fixation has recently been performed in patients in need of cervical reconstruction. We report the case of a 50-year-old man who was operated for traumatic cervical vertebra subluxation using CPS fixation, in whom laminectomy had been performed in the past. We performed CPS fixation using the pedicle axis view technique under fluoroscopy. The four pedicle screws were accurately inserted within the pedicles without perforating the bone cortex of the pedicles. A navigation system is useful for cervical spine surgery because it enables a surgeon to perform relatively safe and accurate surgery during transpedicular screw fixation. However, attachment of the stereotactic reference arc to the spinous process is impossible, and the application of a navigation system is limited in cases in which laminectomy has been performed in the past. We have been using the pedicle axis view technique under fluoroscopy and have found that if we take care of the entry point accurately, we can safely insert the pedicle screw in cases with fewer landmarks.

An evidence-based medicine process to determine outcomes after cervical spine trauma: what surgeons should be telling their patients

STUDY DESIGN

A systematic review of the available medical literature from 1980 to 2010 was conducted and combined with expert opinion from a recent survey of experts regarding cervical spine fractures. Using an objective, hierarchical approach, the best available evidence is presented for health-related quality-of-life outcomes for these injuries.

OBJECTIVE

To provide an evidence-based set of guidelines for cervical spine injuries in order to reduce variability in the information given to patients and their families.

SUMMARY OF BACKGROUND DATA

Patients' expectations regarding quality-of-life outcomes are highly dependent on the information provided by surgeons early in the treatment course. Our previous work has demonstrated that there is substantial variability in what surgeons tell patients regarding outcomes of cervical spine injuries, thus patients' expectations will differ and outcomes vary.

METHODS

Four common cervical spine injuries (C1 burst, Hangman fracture, odontoid fracture, and unilateral facet fracture) treated both surgically and nonsurgically were considered. We assessed the evidence regarding 5 health-related quality-of-life outcomes: time to return to work, activity level, hospital stay, the proportion of patients who are pain free and patients who have regained full range of motion at 1 year after the injury.

RESULTS

Published outcome data were available for most injuries. Using consensus expert opinion and the literature, answers to each question were achieved. Overall, expert opinion was relatively homogeneous across injury types, suggesting that experts do not distinguish between specific injuries when advising patients of expected outcomes such as pain.

CONCLUSION

By overcoming gaps in the literature with consensus expert opinion, our study provides surgeons and others with evidence-based medicine guidelines for patient-centered outcomes after cervical spine injury. This information can be presented to patients to frame expectations of typical outcomes during and after treatment to optimize patient care and quality of life.

Anterior approach for complex cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) is a slowly progressive disease resulting from age-related degenerative changes in the spine that can lead to spinal cord dysfunction and significant functional disability. The degenerative changes and abnormal motion lead to vertebral body subluxation, osteophyte formation, ligamentum flavum hypertrophy, and spinal canal narrowing. Repetitive movement during normal cervical motion may result in microtrauma to the spinal cord. Disease extent and location dictate the choice of surgical approach. Anterior spinal decompression and instrumented fusion is successful in preventing CSM progression and has been shown to result in functional improvement in most patients.

Long-term follow-up of cervical radiographic sagittal spinal alignment after 1- and 2-level cervical corpectomy for the treatment of spondylosis of the subaxial cervical spine causing radiculomyelopathy or myelopathy: a retrospective study

Object

Few data exist regarding long-term outcomes after cervical corpectomy for spondylotic cervical myelopathy and radiculomyelopathy. In this retrospective review, long-term radiographic outcomes are reported for 130 patients after 1- or 2-level cervical corpectomy for spondylotic myelopathy or radiculomyelopathy.

Methods

Electronic medical records including clinical data and radiographic images during a 15-year period (1993–2008) were reviewed at the Cincinnati Department of Veterans Affairs Medical Center. All patients underwent radiographic follow-up for at least 12 months (range 12–156, mean 45 ± 39.3 months), as well as clinical follow-up performed by neurosurgery staff for a mean of 29.3 ± 39.6 months (range 4–156 months). Clinical parameters at surgery and last examination included the Chiles modified Japanese Orthopaedic Association (mJOA) Myelopathy Scale. Measurements included cervical spine sagittal alignment on lateral radiographs preoperatively and postoperatively, focal Cobb angles at operated levels, and C2–7 regional alignment. Statistical analysis included the Student t-test and chi-square test. Perioperative complications and additional surgery in the cervical spine were recorded.

Results

The mJOA scores improved from a mean of 11.91 ± 2.4 preoperatively to 14.9 ± 2.33 postoperatively. The mean sagittal lordosis of the C2–7 spine increased from −16.2° ± 9.2° preoperatively to −18.5° ± 11.9° at last follow-up. Focal Cobb angles averaged a slight kyphotic angulation of 4.1° ± 2.3° at latest radiographic follow-up; of note, 7 patients (5.4%), all who had cylindrical titanium mesh cages (CTMCs), showed severe kyphotic angulation (+8.4° ± 2.4°). Patients with preoperative myelopathy showed clinical improvement at follow-up. The fusion rate was 96.2%; 3 of the 5 patients with radiographic evidence of nonfusion were smokers. Patients with postoperative kyphosis had significantly more chronic neck pain (visual analog scale score >4 lasting more than 6 months) and visits related to pain (p <0.01). Those with CTMCs had higher rates of postoperative kyphosis, chronic neck pain, and visits related to pain, irrespective of the number of levels fused (p <001). At latest follow-up, although a kyphotic increase occurred in the focal cervical sagittal Cobb angles, lordosis increased in C2–7 sagittal Gore angles. Two patients (1.5%) underwent revision of the implanted graft and/or hardware, and 5 patients (3.8%) had another procedure for adjacent-level pathologies 1–9 years later (mean 4.4 ± 2.7 years).

Conclusions

Long-term follow-up data in our veteran population support cervical corpectomy as an effective, long-lasting treatment for spondylotic myelopathy of the cervical spine. Use of CTMCs without end caps was associated with statistically significant increased postoperative kyphotic angulation and chronic pain. Despite an increase in focal kyphosis over time, regional cervical sagittal lordotic alignment had increased at the latest follow-up. Further investigation will include the association of chronic neck pain and postoperative kyphosis, and high fusion rates among a veteran population of heavy smokers.

Posterior approach for cervical fracture-dislocations with traumatic disc herniation

In the treatment algorithm for cervical spine fracture-dislocations, the recommended approach for treatment if there is a disc fragment in the canal is the anterior approach. The posterior approach is not common because of the disadvantage of potential neurological deterioration during reduction in traumatic cervical herniation patients. However, reports about the frequency of this deterioration and the behavior of disc fragments after reduction are scarce. Forty patients with traumatic disc herniation were observed. They represented 29.2% of 137 consecutive patients with subaxial cervical spine fracture-dislocations. Surgical planning was performed according to our two-stage algorithm. In the first stage, they were treated with posterior open reduction and posterior spine arthrodesis. In the second stage, anterior surgery was added for cases where neurological deterioration attributed to non-reduced disc fragments on postoperative magnetic resonance imaging (MRI). Neurological deterioration after posterior open reduction was not observed. Furthermore, 25% of total cases and 75% of incomplete paralysis cases improved postoperatively by ≥ 1 grade in the American Spinal Injury Association impairment scale. Reduction or reversal of disc herniation was observed in all cases undergoing postoperative MRI. For local sagittal alignment, preoperative 9.4° kyphosis was corrected to 6.9° lordosis postoperatively. The disc height ratio was 72.4% preoperatively and 106.3% postoperatively. The second stage of our plan was not required after the posterior approach in this series. The incidence of neurological deterioration after posterior open reduction was zero, even in cases with traumatic cervical disc herniation. Favorable clinical and radiological outcomes could be obtained by the first stage alone. Although preparations for prompt anterior surgery should always be made to cover any contingency, the need for them is minimal.

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.

The impact of fusion on adjacent levels in cervical spine injuries: Is it really important?

OBJECTIVE

Although the literature on degenerative disease of the cervical spine contains numerous articles studying the changes on levels adjacent to a fusion, there exist very few such studies concerning cervical spine stabilization for trauma.

METHODS

Over a 16-year period (1989-2005), one hundred and twelve patients underwent stabilization of the lower cervical spine (C3-T1) for subaxial cervical spine injuries, either with an anterior or posterior procedure, or both. Eighty-one patients with adequate follow-up were included in the study and 3 groups were identified: Group A, consisting of 8 patients who underwent anterior stabilization and developed Adjacent Level Ossification Development (ALOD), Group B, comprising 53 patients who were anteriorly plated but who did not develop ALOD and Group C, comprising 20 patients who received posterior stabilization.

RESULTS

Eight out of 61 patients (13.1%) who were anteriorly operated developed ALOD in 11 adjacent levels (Group A). Severe (grade 3) ossification was noted in 6/8 patients at the cranial adjacent level, and in 2/8 patients at the caudal one. Three out of 8 patients presented with early ALOD at 3, 4 and 18 months respectively. Despite the radiographic abnormalities showing ossification, all the patients had an uncomplicated course without symptoms. All the radiographs of Group B and Group C patients demonstrated grade 0 ossification for both the cranial and caudal adjacent levels.

CONCLUSION

Adjacent-level ossification in cervical spine injuries may appear very early in the postoperative period and it can have a different course than in the degenerative disc disease population, at least in some patients. The first cephalad level adjacent to a fusion appears to be at greater risk. However, even when ALOD is evident radiographically, it very rarely produces any symptoms.

In vitro study of accuracy of cervical pedicle screw insertion using an electronic conductivity device (ATPS part III)

Reconstruction of the highly unstable, anteriorly decompressed cervical spine poses biomechanical challenges to current stabilization strategies, including circumferential instrumented fusion, to prevent failure. To avoid secondary posterior surgery, particularly in the elderly population, while increasing primary construct rigidity of anterior-only reconstructions, the authors introduced the concept of anterior transpedicular screw (ATPS) fixation and plating. We demonstrated its morphological feasibility, its superior biomechanical pull-out characteristics compared with vertebral body screws and the accuracy of inserting ATPS using a manual fluoroscopically assisted technique. Although accuracy was high, showing non-critical breaches in the axial and sagittal plane in 78 and 96%, further research was indicated refining technique and increasing accuracy. In light of first clinical case series, the authors analyzed the impact of using an electronic conductivity device (ECD, PediGuard) on the accuracy of ATPS insertion. As there exist only experiences in thoracolumbar surgery the versatility of the ECD was also assessed for posterior cervical pedicle screw fixation (pCPS). 30 ATPS and 30 pCPS were inserted alternately into the C3-T1 vertebra of five fresh-frozen specimen. Fluoroscopic assistance was only used for the entry point selection, pedicle tract preparation was done using the ECD. Preoperative CT scans were assessed for sclerosis at the pedicle entrance or core, and vertebrae with dense pedicles were excluded. Pre- and postoperative reconstructed CT scans were analyzed for pedicle screw positions according to a previously established grading system. Statistical analysis revealed an astonishingly high accuracy for the ATPS group with no critical screw position (0%) in axial or sagittal plane. In the pCPS group, 88.9% of screws inserted showed non-critical screw position, while 11.1% showed critical pedicle perforations. The usage of an ECD for posterior and anterior pedicle screw tract preparation with the exclusion of dense cortical pedicles was shown to be a successful and clinically sound concept with high-accuracy rates for ATPS and pCPS. In concert with fluoroscopic guidance and pedicle axis views, application of an ECD and exclusion of dense cortical pedicles might increase comfort and safety with the clinical use of pCPS. In addition, we presented a reasonable laboratory setting for the clinical introduction of an ATPS-plate system.

C2-fractures: part II. A morphometrical analysis of computerized atlantoaxial motion, anatomical alignment and related clinical outcomes

Knowledge on the outcome of C2-fractures is founded on heterogenous samples with cross-sectional outcome assessment focusing on union rates, complications and technical concerns related to surgical treatment. Reproducible clinical and functional outcome assessments are scant. Validated generic and disease specific outcome measures were rarely applied. Therefore, the aim of the current study is to investigate the radiographic, functional and clinical outcome of a patient sample with C2-fractures. Out of a consecutive series of 121 patients with C2 fractures, 44 met strict inclusion criteria and 35 patients with C2-fractures treated either nonsurgically or surgically with motion-preserving techniques were surveyed. Outcome analysis included validated measures (SF-36, NPDI, CSOQ), and a functional CT-scanning protocol for the evaluation of C1-2 rotation and alignment. Mean follow-up was 64 months and mean age of patients was 52 years. Classification of C2-fractures at injury was performed using a detailed morphological description: 24 patients had odontoid fractures type II or III, 18 patients had fracture patterns involving the vertebral body and 11 included a dislocated or a burst lateral mass fracture. Thirty-one percent of patients were treated with a halo, 34% with a Philadelphia collar and 34% had anterior odontoid screw fixation. At follow-up mean atlantoaxial rotation in left and right head position was 20.2 degrees and 20.6 degrees, respectively. According to the classification system of posttreatment C2-alignment established by our group in part I of the C2-fracture study project, mean malunion score was 2.8 points. In 49% of patients the fractures healed in anatomical shape or with mild malalignment. In 51% fractures healed with moderate or severe malalignment. Self-rated outcome was excellent or good in 65% of patients and moderate or poor in 35%. The raw data of varying nuances allow for comparison in future benchmark studies and metaanalysis. Detailed investigation of C2-fracture morphology, posttreatment C2-alignment and atlantoaxial rotation allowed a unique outcome analysis that focused on the identification of risk factors for poor outcome and the interdependencies of outcome variables that should be addressed in studies on C2-fractures. We recognized that reduced rotation of C1-2 per se was not a concern for the patients. However, patients with worse clinical outcomes had reduced total neck rotation and rotation C1-2. In turn, C2-fractures, especially fractures affecting the lateral mass that healed with atlantoaxial deformity and malunion, had higher incidence of atlantoaxial degeneration and osteoarthritis. Patients with increased severity of C2-malunion and new onset atlantoaxial arthritis had worse clinical outcomes and significantly reduced rotation C1-2. The current study offers detailed insight into the radiographical, functional and clinical outcome of C2-fractures. It significantly adds to the understanding of C2-fractures.