Traumatic Atlanto-occipital Dislocation: Analysis of 15 Survival Cases With Emphasis on Associated Upper Cervical Spine Injuries.

STUDY DESIGN: Retrospective case analyses. OBJECTIVE: The aim of this study was to investigate the incidence and characteristics of associated upper cervical spine injuries in 15 survival cases of traumatic atlanto-occipital dislocation (AOD). SUMMARY OF BACKGROUND DATA: Traumatic AOD is a rare and generally fatal injury. Information regarding associated upper cervical spine injuries that may affect treatment methods, outcomes, and prognosis is limited. METHODS: Fifteen patients (11 patients with posterior-type AOD and four patients with vertical-type AOD) who survived traumatic AOD were included in this study. Plain radiographs, computed tomography, magnetic resonance imaging, and medical records were reviewed. The incidence and characteristics of associated upper and lower cervical spine and thoracolumbar spine injuries and brain injuries were evaluated. RESULTS: Thirteen patients with traumatic AOD (11 patients with posterior-type AOD and two patients with vertical-type AOD) showed associated upper cervical spine injuries; the overall incidence was 87% (100% in posterior-type AOD and 50% in vertical-type AOD). In posterior-type AOD, eight (72.7%) patients had C1 fractures (four patients had three-part fracture, three patients had two-part fracture, and one patient had four-part fracture), four (36.4%) patients had C1 lateral mass fractures, two (18.2%) patients had transverse atlantal ligament injuries. In vertical-type AOD, two (50%) patients had C1-C2 vertical subluxation with C1 anterior arch horizontal and sagittal split fractures. In posterior-type AOD, two (18%) patients had lower cervical spine injuries and one (9%) patient had brain injury. In vertical-type AOD, one (25%) patient had thoracic spine injury, and three (75%) patients had brain injuries additionally. CONCLUSION: Survival cases with traumatic AOD showed a high incidence of associated upper cervical spine injuries and brain injuries. High index of suspicion and careful radiologic examination are needed to investigate the presence of associated upper cervical spine injuries and brain injuries in traumatic AOD, which affects treatment, outcome, and prognosis. LEVEL OF EVIDENCE: 4.

Prognosis of Hardware-Related Problems in Anterior Cervical Discectomy and Fusion with Cage and Plate Constructs.

OBJECTIVE: To analyze hardware-related problems and their prognoses after anterior cervical discectomy and fusion (ACDF) using cages and plates for degenerative and traumatic cervical disc diseases. METHODS: The study included 808 patients who underwent anterior cervical discectomy and fusion for degenerative and traumatic disc diseases with >1 year of follow-up. We investigated time of onset and progression of problems associated with instrumentation and cage usage. The mean follow-up time was 3.4 years. Type of plate, range and level of fusion, patient factors (age, sex, body mass index, and bone mineral density), and local kyphosis were evaluated. RESULTS: Complications were found in 132 cases (16.5%), including subsidence in 69 cases, plate loosening in 8 cases, screw loosening in 8 cases, screw breakage in 1 case, and multiple complications in 36 cases. In 3 cases, additional posterior cervical surgery was performed. One case needed hardware revision. There were no esophageal, tracheal, or neurovascular structural injuries secondary to metal failure. There were no significant differences in type of plate, level of surgery, or patient factors. The greater the number of fusion segments, the greater the incidence of complications (P = 0.001). The clinical outcomes improved regardless of the complications (P = 0.083). CONCLUSIONS: Most hardware-related complications are not symptomatic and can be treated conservatively. Only a few cases need revision surgery. Precise surgical techniques are needed in multilevel anterior cervical discectomy and fusion (>3 levels) because of the increased complication rate.

Radiologic criteria to predict injury of the transverse atlantal ligament in unilateral sagittal split fractures of the C1 lateral mass.

Unilateral sagittal split fracture (USSF) of the C1 lateral mass (LM) has been recently recognized as a rare variant of C1 atlas fracture. To date, there has been no study to investigate whether radiologic criteria can be applied to determine the presence or absence of transverse atlantal ligament (TAL) injury in USSF of the C1 LM.Twenty six consecutive cases of USSF of the C1 LM were included in this study. According to Dickman classification, 16 cases were TAL injury, and 10 cases were TAL intact. Radiologic parameters were measured and compared between the 2 groups.Total LM displacement (LMD) of the 2 sides (5.9 ±â€Š2.0 mm vs 1.2 ±â€Š2.0 mm), unilateral LMD of the fracture side (4.3 ±â€Š1.2 mm vs 1.0 ±â€Š1.1 mm), atlanto-dental interval (ADI) (2.0 ±â€Š0.9 mm vs 1.5 ±â€Š0.4 mm), and fracture gap (6.9 ±â€Š2.7 mm vs 2.1 ±â€Š1.1 mm) were statistically higher in the TAL injury group than the TAL intact group. However, basion-dental interval, clivus canal angle, and atlanto-occipital joint axis angle were not different between the 2 groups. Total LMD and unilateral LMD positively correlated with ADI and fracture gap. The incidence of fracture gap larger than 7 mm was statistically higher in the TAL injury group than the TAL intact group (81% vs 30%).In conclusion, total LMD > 5.9 mm or unilateral LMD > 4.3 mm suggests the presence of TAL injury in USSF of the C1 LM. The possibility of diagnostic error for TAL injury can be further reduced in USSF of the C1 LM by considering the fracture gap larger than 7 mm.

Etiology and Related Factors of Postoperative Delirium in Orthopedic Surgery.

BACKGROUND: Delirium is a serious complication for elderly patients after orthopedic surgery. The purpose of this study was to assess the etiology and related factors of delirium after orthopedic surgery in Korea. METHODS: We retrospectively reviewed the medical records of 3,611 patients over 50 years who had orthopedic surgery. The age of patients (50s, 60s, 70s, and > 80s), type of anesthesia (general, spinal, and local), operation time (more than 2 hours vs. less than 2 hours), surgical site (spine, hip, knee, or others), and etiology (trauma or disease) were compared to determine possible risk factors of delirium after orthopedic surgery. RESULTS: Of 3,611 patients, 172 (4.76%) were diagnosed with delirium after orthopedic surgery. Postoperative delirium occurred in 1.18% in their 50s, 3.86% in their 60s, 8.49% in their 70s, and 13.04% in > 80s (p < 0.001). According to anesthesia type, 6.50% of postoperative delirium occurred after general anesthesia, 0.77% after spinal anesthesia, and 0.47% after local anesthesia (p < 0.001). More than 2 hours of operation was associated with higher occurrence of delirium than less than 2 hours was (5.88% vs. 4.13%, p = 0.017). For the etiology, 8.17% were trauma cases and 3.02% were disease (p < 0.001). Postoperative delirium occurred in 22 of 493 patients (4.46%) after spine surgery, 18 of 355 patients (5.07%) after hip surgery, 17 of 394 patients (4.31%) after knee surgery, and 15 of 1,145 patients (1.31%) after surgery at other sites (p < 0.001). CONCLUSIONS: Postoperative delirium was more common in older patients who had surgery under general anesthesia, whose surgery took more than 2 hours, and who were hospitalized through the emergency room.

Clinical and radiological outcomes of conservative treatment for unilateral sagittal split fractures of C1 lateral mass.

OBJECTIVE: The aim of this study was to assess the effect of transverse atlantal ligament (TAL) integrity on clinical and radiological outcomes in patients with unilateral sagittal split fracture (USSF) of the C1 lateral mass (LM). METHODS: Twenty-six consecutive patients (16 men and 10 women; mean age: 52 years (range: 32-69)) with C1 LM USSF were included in this study. Sixteen were TAL injury group (nine of type I injuries and seven of type II injuries according to Dickman's classification) and ten were TAL intact group. All cases were conservatively treated with a rigid brace for TAL intact or by halo-vest stabilization for TAL injury for three months. The mean follow-up was 16 months (range, 12-47 months). The results were compared with radiological assessment of fracture healing, LM displacement and Neck visual analog scale. RESULTS: At the last follow-up, for TAL intact group, total LM displacement (LMD), unilateral LMD of fracture side, atlanto-dental interval, basion-dental interval, clivus canal angle, and atlanto-occipital joint axis angle were maintained compared to initial presentation. However, for TAL injury group, all radiological parameters were worsened. The worsening of radiological parameters was more severe in type I injury than type II injury except for total LMD and unilateral LMD. Neck visual analog scale significantly decreased and patient's satisfaction was higher in TAL intact group compared to TAL injury group. CONCLUSION: Conservative treatment for USSF of C1 LM with TAL injury failed to achieve healing of the fracture, which resulted in lateral displacement of C1 LM. This caused coronal and sagittal malalignment of occipitocervical junction, resulting in unsatisfactory clinical outcomes. Our results suggest that early surgical stabilization should be considered in USSF of C1 LM with TAL injury, especially type I injury. However, conservative treatment may be sufficient for a USSF of the C1 LM with TAL intact. LEVEL OF EVIDENCE: Level III, Therapeutic Study.

Esophageal Perforation after Anterior Cervical Spine Surgery.

STUDY DESIGN: Retrospective case analyses. PURPOSE: To investigate the causes, diagnosis, and management of esophageal perforation, depending on the time of diagnosis. OVERVIEW OF LITERATURE: To date, few studies have addressed these issues. METHODS: A total of seven patients were included in this study. The patients were classified into three groups based on esophageal perforation diagnosis time: intraoperative (diagnosed during surgery), perioperative (diagnosed within 30 days postoperatively), and delayed (diagnosed >30 days postoperatively) groups. RESULTS: In the intraoperative group (N=2), infectious spondylitis was the main cause of esophageal perforation. Anterior plate and screw removal, followed by posterior instrumentation, was performed. The injured esophagus was managed by omentum flap repair in one patient and primary repair in one patient. In the perioperative group (N=2), revision surgery for infection and metal failure were the main causes of esophageal perforation. In both cases, food residue was drained on the third postoperative day. The injured esophagus was managed conservatively. In the delayed group (N=3), chronic irritation caused by metal failure was the main cause of esophageal perforation. In all patients, there was no associated infection. The anterior instrumentation was removed, and the two patients were treated by primary repair, and one patient was treated using sternocleidomastoid muscle flap. One patient in intraoperative group died of sepsis. CONCLUSIONS: The main cause of intraoperative esophageal perforation was esophageal adhesions because of infectious spondylitis. However, perioperative and delayed esophageal perforations were caused by chronic irritation because of metal failure. Anterior plate and screw removal was necessary, and posterior instrumentation and fusion may be considered, depending on the fusion status.

Acute airway obstruction due to postoperative retropharyngeal hematoma after anterior cervical fusion: a retrospective analysis.

BACKGROUND: Acute airway obstruction (AAO) after anterior cervical fusion (ACF) can be caused by postoperative retropharyngeal hematoma, which requires urgent recognition and treatment. However, the causes, evaluation, and appropriate treatment of this complication are not clearly defined. The purpose of this retrospective review of a prospective database was to investigate etiologic factors related to the development of AAO due to postoperative hematoma after ACF and formulate appropriate prevention and treatment guidelines. METHODS: Cervical spinal cases treated at our academic institutions from 1998 to 2013 were evaluated. Demographic data, including factors related to hemorrhagic tendency, and operative data were analyzed. Patients who developed a hematoma were compared with those who did not to identify risk factors. Cases complicated by hematoma were reviewed, and times until development of hematoma and surgical evacuation were determined. Degrees of airway compromise and patient behavior were classified and evaluated. Treatment was selected according to the patient's status. RESULTS: Among 785 ACF procedures performed, there were nine cases (1.15%) of AAO. None of these nine patients had preoperative risk factors. In six patients (67%), the hematoma occurred within 24 h, whereas three patients (33%) presented with hematoma at a median of 72 h postoperatively. Four of the nine patients with AAO underwent evacuation of the hematoma. Two patients with inspiratory stridor, anterior neck swelling, and facial edema progressed to respiratory distress and their hematomas were removed by surgery, during which, sustained superficial venous bleeding was confirmed. Intubation was attempted several times in one patient with cyanosis, but is unsuccessful; cricothyroidotomy was performed in this patient and pumping in the small muscular arterial branches was confirmed in the operating room. All of the patients recovered without any complications. CONCLUSIONS: With rapid recognition and appropriate treatment, there were no long-term complications caused by postoperative hematoma. There were no specific preoperative risk factors for hematoma. Systematic evaluation and appropriate management can be helpful for preventing serious complications after development of a postoperative hematoma.

Limitation of previous Allen classification and subaxial cervical spine injury classification (SLIC) system in distractive-extension injury of cervical spine: proposal of modified classification system.

PURPOSE: To verify the clinical applicability of a modified classification system in distractive-extension cervical spine injury that reflects the degrees of soft tissue damage and spinal cord injury while complementing previous Allen classification and subaxial cervical spine injury classification (SLIC) system. METHODS: A total of 195 patients with cervical spine distraction-extension (DE) injury were retrospectively classified. We added stages IIIA (with concomitant spinal cord injury without bony abnormalities) and IIIB (with concomitant additional soft tissue swelling) to the existing stages I and II of the Allen classification. We also supplemented the SLIC system by refining and assigning scores to bony morphology and soft tissue damage. The previous and proposed classification systems were compared by analyzing their scoring performances in terms of clinical features and prognosis. RESULTS: The Allen classification yielded 153 and 42 patients with stage 1 and 42 stage 2 injuries, respectively. Patients classified according to the proposed system were stratified as follows: stage I, 58; stage II, 27; stage IIIA, 33; and stage IIIB, 77. Regarding neurological symptoms and prognosis, stages IIIA and IIIB were poorer than stage I but significantly better than stage II (P < 0.05). On the SLIC system, 146 patients scored ≥5; and 37 and 12 patients scored 4 and ≤3 points, respectively, whereas the numbers of patients who scored ≥5, 4, and ≤3 points on the modified SLIC system were 170, 21, and 4, respectively. CONCLUSIONS: The proposed classification and scoring system to complement the Allen classification and SLIC system with respect to the degrees of soft tissue damage and spinal cord injury is considered effective for diagnosing and determining therapeutic directions and prognosis in cases of cervical spine extension injury.

Relationship between magnetic resonance imaging findings and spinal cord injury in extension injury of the cervical spine.

OBJECTIVE: The purpose of this study was to determine the relationship between magnetic resonance imaging (MRI) findings and neurologic symptoms in cervical spine extension injury and to analyze the MRI parameters associated with neurologic outcome. MATERIALS AND METHODS: This study included 102 patients with cervical spine extension injury, whose medical records and MRI scans at the time of injury were available. Quantitative MRI parameters such as maximum spinal canal compression (MSCC), maximum cord compromise (MCC), and lesion length showing intramedullary signal changes were measured. Furthermore, intramedullary hemorrhage, spinal cord edema, and soft tissue damage were evaluated. Fisher's exact test was used for a cross-analysis between the MRI findings and the three American Spinal Injury Association category groups depending on the severity level of neurologic injury: complete (category A), incomplete (categories B-D), and normal (category E). RESULTS: MSCC accounted for 23.05, 19.5, and 9.94 % for the complete, incomplete, and normal AIS categories, respectively, without showing statistically significant differences (P = 0.085). MCC was noted in 22.05, 15.32, and 9.2 %, respectively, with the complete-injury group (AIS category A) showing significantly higher. In particular, cases of complete injury had >15 % compression, accounting for 87.5 % (P < 0.001). The mean intramedullary lesion length was significantly higher in complete-injury patients than in incomplete-injury patients (24.22 vs. 8.24 mm). Intramedullary hemorrhage and spinal cord edema were significantly more frequently observed in complete-injury cases (P < 0.001). The incidence of complete injury was proportional to the severity of soft tissue damage. CONCLUSION: MCC, intramedullary lesion length, intramedullary hemorrhage, and spinal cord edema were MRI parameters associated with poor neurologic outcomes in patients with cervical spine extension injury.

Relationship Between Percutaneous Procedures and Lumbar Infections Based on Data From The National Health Insurance Review & Assessment Service of Korea.

STUDY DESIGN: A study from the National health insurance database. OBJECTIVE: To investigate the relationship between percutaneous procedures or open surgeries and spinal infections using the 5-year large unit national dataset. SUMMARY OF BACKGROUND DATA: There is no nation-based research data on the relationship between percutaneous procedures and spinal infections in Korea. MATERIALS AND METHODS: This study used disease codes (ICD-10: International Classification of Disease) and operation fee codes (national medical insurance) registered in the National Health Insurance Review & Assessment Service for the 5 years from 2007 to 2011. Using the above disease codes, the number of each percutaneous procedure, open surgery, and the number of lumbar infections were investigated by the regional and national units, and the relationship between procedures or open surgeries and lumbar infection was compared statistically. RESULTS: Lumbar infection showed a gradual growing annual trend, with a 3-fold increase in 2011 compared with 2007. Percutaneous procedures (nerve blocks) increased by approximately 2.6 times over 4 years. Kyphoplasty tended to decrease each year. Open surgeries (posterior fusion, discectomy, and laminectomy) were at a similar level each year. Lumbar infection and percutaneous procedures were positively correlated, and a negative correlation was observed between kyphoplasty and open surgeries. The incidence of lumbar infection was higher in large cities than provinces and increased 2-3 times in 2011 compared with 2007 in all regions. CONCLUSIONS: There was no significant difference in the number of open surgeries for the 5-year study, but the number of percutaneous procedures (nerve blocks) increased each year, showing an approximate 4-fold increase in 4 years. Lumbar infection showed a positive correlation with percutaneous procedures, and kyphoplasty and open surgeries were negatively correlated. Therefore, as selective nerve block procedure is also considered an important factor affecting the growing trend of lumbar infections, unnecessary procedures should be avoided to reduce the absolute number of infections.

Prognostic Factors for Postsurgical Recovery of Deltoid Palsy due to Cervical Disc Herniations.

STUDY DESIGN: Retrospective multicenter study. PURPOSE: We aimed to investigate prognostic factors affecting postsurgical recovery of deltoid palsy due to cervical disc herniation (CDH). OVERVIEW OF LITERATURE: Little information is available about prognostic factors affecting postsurgical recovery of deltoid palsy due to CDH. METHODS: Sixty-one patients with CDH causing deltoid palsy (less than grade 3) were included in this study: 35 soft discs and 26 hard discs. Average duration of preoperative deltoid palsy was 11.9 weeks. Thirty-two patients underwent single-level surgery, 22 two-level, four three-level, and three four-level. Patients with accompanying myelopathy, shoulder diseases, or peripheral neuropathy were excluded from the study. RESULTS: Deltoid palsy (2.4 grades vs. 4.5 grades, p<0.001) and radiculopathy (6.4 points vs. 2.1 points, p<0.001) significantly improved after surgery. Thirty-six of 61 patients (59%) achieved full recovery (grade 5) of deltoid palsy, with an average time of 8.4 weeks. Longer duration of preoperative deltoid palsy and more severe radiculopathy negatively affected the degree of improvement in deltoid palsy. Age, gender, number of surgery level, and disc type did not affect the degree of improvement of deltoid palsy. Contrary to our expectations, severity of preoperative deltoid palsy did not affect the degree of improvement. Due to the shorter duration of preoperative deltoid palsy, in the context of rapid referral, early surgical decompression resulted in significant recovery of more severe grades (grade 0 or 1) of deltoid palsy compared to grade 2 or 3 deltoid palsy. CONCLUSIONS: Early surgical decompression significantly improved deltoid palsy caused by CDH, irrespective of age, gender, number of surgery level, and disc type. However, longer duration of deltoid palsy and more severe intensity of preoperative radiating pain were associated with less improvement of deltoid palsy postoperatively.

Prognostic factors in distractive extension injuries of the subaxial cervical spine.

BACKGROUND: The subaxial spine has high risk of fatal damage by trauma and thereby requires more accurate and aggressive treatment. For the proper treatment and predicting the prognosis, the evaluation to reveal the risk factors for the prognosis is important. We analyzed the various factors contributing to the prognosis in distractive extension injuries of the subaxial cervical spine. METHODS: The study included 103 patients who were diagnosed as distractive extension injury of subaxial cervical spine. We evaluate the patient age, sex, cause of injury, initial neurological impairment, number and portion of injured segment, spinal stenosis, extent of soft tissue damage, ossification of the posterior longitudinal ligament, and degenerative spondylosis as a prognostic factor. To analyze the factor related with prognosis, the subjects were divided into group A, in which patients had neurological recovery ≥grade 2 on the ASIA scale or showed normal in final follow-up and group B, in which patients have no neurological recovery. RESULTS: Prognosis was not associated with age, sex, and cause of injury (P = 0.677, 0.541, and 0.965, respectively). Prognosis was poor in cases with spinal stenosis (P = 0.009), soft tissue damage ≥grade 3 on magnetic resonance imaging (MRI) (P = 0.002), or severe neurological impairment (P ≤ 0.001). Logistic regression analysis also showed that prognosis was poor in cases with spinal stenosis (OR 5.03; 95% CI 1.20-16.93), soft tissue damage ≥grade 3 on MRI (OR 7.63; 95% CI 1.86-31.34), or severe neurological impairment (ASIA C, D, OR 0.59, 95% CI 0.14-2.41; ASIA A, B, OR 18.43, 95% CI 1.64-207.69). CONCLUSION: The prognosis of patients with distractive extension injury of the subaxial cervical spine was poor in cases with spinal stenosis, severe soft tissue damage in MRI findings or severe initial neurological impairment.

Current concepts of anterior cervical discectomy and fusion: a review of literature.

Anterior cervical discectomy and fusion (ACDF) is a safe and effective procedure for degenerative cervical spinal disease unresponsive to conservative management and its outstanding results have been reported. To increase fusion rates and decrease complications, numerous graft materials, cage, anterior plating and total disc replacement have been developed, and better results were reported from those, but still there are areas that have not been established. Therefore, we are going to analyze the treatment outcome with the various procedure through the literature review and determine the efficacy of ACDF.

The clinical efficacy of short-term steroid treatment in multilevel anterior cervical arthrodesis.

BACKGROUND CONTEXT: Dysphagia is the most common complication of anterior cervical discectomy and fusion (ACDF), and it is closely related to prevertebral soft-tissue swelling (PSTS). A few studies have found that local or systemic methylprednisolone is effective against laryngopharyngeal edema and airway obstruction. PURPOSE: To assess the effectiveness of short-term use of systemic methylprednisolone in relieving dysphagia and decreasing PSTS during the hospitalization period. STUDY DESIGN: A prospective study. PATIENT SAMPLE: Forty patients who underwent multilevel (more than three levels) ACDF with same plate fixation. OUTCOME MEASURE: Radiologic and clinical measures. METHODS: Twenty of these patients were given 250 mg of methylprednisolone intravenously (IV) four times a day only for 24 hours after the operation (at 6-hour intervals), whereas the remaining 20 did not receive methylprednisolone and served as controls. We used the Bazaz scale to compare the degree of dysphagia between groups during the hospitalization period. We used the C-spine lateral view to assess the degree of pre- and postoperative PSTS from C2 to C7. At the final follow-up, we assessed the relationship between the occurrence of complications and steroid use. RESULTS: The degree of dysphagia according to the Bazaz scale was less severe in the group that received methylprednisolone (p values; postoperative Day [POD] 2∼5<.05, POD 6=.014, POD 7=.019). Prevertebral soft-tissue swelling was also significantly lower in the group that received methylprednisolone (p values; POD 2∼POD 5 <.005, POD 1=.061, POD 6=.007, POD 7=.091). The amount of PSTS and dysphagia did not differ according to sex, age, smoking history, or length of surgery. The period of hospitalization in the experimental group was shorter than in the control group. No complications related to steroid use were found at the final follow-up. CONCLUSIONS: The short-term use of systemic methylprednisolone after ACDF appears to be effective in relieving dysphagia and decreasing the PSTS. Furthermore, the short-term use of methylprednisolone was not associated with any adverse effects of short-term IV steroid usage, such as peptic ulcer disease or postoperative infection. The clinical use of methylprednisolone in relieving dysphagia and decreasing PSTS deserves consideration during the early postoperative period.

Is OPLL-induced canal stenosis a risk factor of cord injury in cervical trauma?

The purpose of this study is to identify the relationship between trauma severity and the degree of cord injury in patients with ossification of posterior longitudinal ligament (OPLL). Four-hundred-one patients were classified into Group A (OPLL(+)), Group B (spinal stenosis (+) and OPLL(-)), and Group C (OPLL (-) and spinal stenosis(-)). Trauma severity and neurological injury severity were compared according to presence of OPLL and spinal stenosis. OPLL was associated with a higher incidence of neurological injury with statistical significance (p = 0.002), whereas spinal stenosis did not (p = 0.408). With Group B+C (no OPLL group) in M (minimal) trauma group as baseline, Group A in M trauma group showed about 5 times, and Group A in S (severe) trauma group showed about 16 times as many cord injury. Patients with OPLL more frequently sustained spinal cord injury from minimal trauma.

Positional change of hyoid bone after anesthesia in anterior surgery of upper cervical spine.

BACKGROUND CONTEXT: The hyoid bone is used as a landmark in anterior upper cervical spine operations and is supposed to represent the level of C3 body. However, this correspondence between hyoid bone position and cervical level is not static and changes during surgery (extension after anesthesia). PURPOSE: To find the cervical level corresponding to the position of hyoid bone before and after anesthesia and to evaluate the adequacy of its usage as a surgical landmark. STUDY DESIGN: A retrospective study. PATIENT SAMPLE: One hundred twenty-eight patients with degenerative cervical diseases who had undergone anterior cervical discectomy and fusion. OUTCOME MEASURE: Radiologic measure. METHODS: For each patient, preanesthesia neutral, preanesthesia extension, and postanesthesia induction extension C-spine lateral image were obtained. The level of cervical vertebra that midline of hyoid bone indicated was measured by radiological method. A cervical vertebra was divided into three segments, consisting of upper half, lower half, and disc space, and each of these segments was considered as one level. The differences between pre- and postanesthesia induction hyoid positions were classified as minimal change (one level or less) and significant change (two levels or greater). Relationship between positional change of hyoid bone to gender, obesity, and age were respectively investigated. RESULTS: There were 20 cases of one-level distal displacement of the hyoid bone, 40 cases of two-level distal displacement, 34 cases of three-level distal displacement, 16 cases of 4-level distal displacement, and two cases of five-level distal displacement. In eight cases, there was no level change, and in the remaining 8 cases, the hyoid bone had been displaced proximally. There were 34 cases of minimal change. The remaining 94 cases (73.4%) had significant changes. No respective relationship was found between sex, obesity, age and pre-and postanesthesia induction positional change of hyoid bone. CONCLUSIONS: Among the 128 cases studied, 73.4% hyoid bone positions had changed by more than one cervical vertebra body between the pre- to postanesthesia induction X-ray images. Sex, age, and body mass index were not associated with statistically significant differences in these positions. The hyoid bone should not be trusted as a landmark for upper cervical operations, and the cervical level to be operated should be confirmed by a radiological method before a skin incision is made.

Risk factors for the development of adjacent segment disease following anterior cervical arthrodesis for degenerative cervical disease: comparison between fusion methods.

This study aimed to determine the risk factors for developing adjacent segment disease (ASDz) after anterior cervical arthrodesis for the treatment of degenerative cervical disease by analyzing patients treated with various fusion methods. We enrolled 242 patients who had undergone anterior cervical fusion for degenerative cervical disease, and had at least 5years of follow-up. We evaluated the development of ASDz and the rate of revision surgery. To identify the risk factors for ASDz, the sagittal alignment, spinal canal diameter, range of motion of the cervical spine, number of fusion segments, and fusion methods were evaluated. The patients were divided into three groups according to the fusion method: Group A contained patients who had received autogenous bone graft only (53 patients), Group B contained patients who received autogenous bone graft and plate augmentation (62 patients), and Group C contained patients who underwent cage and plate augmentation (127 patients). ASDz occurred in 33 patients, of whom 19 required additional surgery. The risk of developing ASDz was significantly higher in male patients (p=0.043), patients whose range of motion of the cervical spine was >30° (p=0.027), and patients with spinal canal stenosis (p=0.010). The rate of development of ASDz was not different depending on the number of fusion segments. The rate of development of ASDz was 41.5% in Group A, 9.6% in Group B, and 5.51% in Group C (p=0.03). In patients who underwent anterior cervical arthrodesis for degenerative disease, the occurrence of ASDz was related to age, the cervical spine range of motion, and spinal canal stenosis. Additional plate augmentation for anterior cervical arthrodesis surgery can lower the rate of ASDz development.

Efficacy of combined anteroposterior fusion with no plate versus anterior fusion alone with cage and plate for multilevel degenerative cervical disease.

BACKGROUND CONTEXT: Many studies have reported that anterior fusion alone has high rates of complications, such as pseudoarthrosis, graft subsidence, and graft dislodgement, with multisegmental constructs. No previous studies have compared the outcomes of combined anteroposterior fusion with no plate and anterior fusion alone with a cage and plate. PURPOSE: To compare the efficacy of combined anteroposterior fusion with that of anterior fusion alone for the treatment of multisegmental degenerative cervical disorder. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: Sixty-two consecutive patients who underwent anterior fusion alone with a cage and plate or combined anteroposterior fusion with no plate for multisegmental (three or more segments) degenerative cervical disease. OUTCOME MEASURE: Radiological and clinical outcome measures. METHODS: Patients in group A (n=36) underwent anterior fusion with a cage and plate construct (AFA); patients in group B (n=26) underwent combined anterior fusion with a cage and posterior fusion with a rod/screw construct (CAPF). The degree and maintenance of the correction angle, fusion rates, and adjacent level degeneration were assessed with radiographs. Clinical outcomes were assessed with a visual analog scale (VAS) and Neck Disability Index (NDI) scores, operative time, blood loss, and rates of complications. RESULTS: The mean correction angle did not differ significantly between groups, but the loss of correction at final follow-up was greater in group A than group B (p=.001). Compared with group B, group A had a higher incidence of pseudarthrosis (p=.035), cage subsidence (p=.005), hardware-related complications (p=.032), and dysphagia (p=.012). The mean VAS score for arm pain and the mean NDI score were better for group B than group A (p=.0461, .0360), but the mean VAS score for posterior neck pain was better for group A than group B (p=.0352). Group B had greater blood loss and a longer operative time than group A (blood loss: p=.037; operative time: p=.0001). CONCLUSIONS: Although combined anterior/posterior fusion is associated with a longer operative time and greater blood loss than anterior fusion alone, the combined approach provides better maintenance of sagittal alignment, a higher rate of fusion, a lower incidence of cage subsidence and adjacent level disease, and better VAS and NDI scores.

Adjacent segment pathology following anterior decompression and fusion using cage and plate for the treatment of degenerative cervical spinal diseases.

STUDY DESIGN: Retrospective study. PURPOSE: To analyze the incidence and prevalence of clinical adjacent segment pathology (CASP) following anterior decompression and fusion with cage and plate augmentation for degenerative cervical diseases. OVERVIEW OF LITERATURE: No long-term data on the use of cage and plate augmentation have been reported. METHODS: The study population consisted of 231 patients who underwent anterior cervical discectomy and fusion (ACDF) with cage and plate for degenerative cervical spinal disease. The incidence and prevalence of CASP was determined by using the Kaplan-Meier survival analysis. To analyze the factors that influence CASP, data on preoperative and postoperative sagittal alignment, spinal canal diameter, the distance between the plate and adjacent disc, extent of fusion level, and the presence or absence of adjacent segment degenerative changes by imaging studies were evaluated. RESULTS: CASP occurred in 15 of the cases, of which 9 required additional surgery. At 8-year follow-up, the average yearly incidence was 1.1%. The rate of disease-free survival based on Kaplan-Meier survival analysis was 93.6% at 5 years and 90.2% at 8 years. No statistically significant differences in CASP incidence based on radiological analysis were observed. Significantly high incidence of CASP was observed in the presence of increased adjacent segment degenerative changes (p<0.001). CONCLUSIONS: ACDF with cage and plate for the treatment of degenerative cervical disease is associated with a lower incidence in CSAP by 1.1% per year, and the extent of preoperative adjacent segment degenerative changes has been shown as a risk factor for CASP.

Comparison of the osteogenic potential of bone dust and iliac bone chip.

BACKGROUND CONTEXT: There is no comparative study of the in vitro and in vivo osteogenic potential of iliac bone chips (autogenous iliac cancellous bone chips) compared with bone dusts generated during the decortication process with a high-speed burr in spine fracture or fusion surgery. PURPOSE: To compare the osteogenic potential of three sizes of bone dusts with iliac bone chips and to determine whether bone dusts can be used as a bone graft substitute. STUDY DESIGN: In vitro and in vivo study. METHODS: Bone chips were harvested from the posterior superior iliac spine and bone dusts from the vertebrae of 15 patients who underwent spinal fracture surgery. Bone dust was divided into three groups: small (3 mm), middle (4 mm), and large (5 mm) according to the size of the burr tip. A comparison was made using a cell proliferation assay, alkaline phosphatase (ALP) activity, the degree of mineralization in an in vitro model, and radiographic and histologic studies (the change of absorbable area and tissue density) after implantation of the various materials into back muscles of nude mice. RESULTS: Although all three bone dust groups were less active with regard to cell proliferation, ALP activity, and the degree of mineralization, than were bone chips, they still exhibited osteogenic potential. Furthermore, there was no significant difference among the three bone dust groups. The three bone dust groups did show greater absorbable area and change of the tissue density than did the iliac bone chip group. Again, there was no significant difference among the three bone dust groups in this regard. Histologically, specimens from the bone dust groups had a higher osteoclast cell number than specimens from the iliac bone chip group. CONCLUSIONS: The osteogenic potential of bone dusts is lower than that of iliac bone chips, and the absorption speed of bone dusts in vivo is faster than that of iliac bone chips. The increased resorption speed appeared to result from an increase in osteoclast cell number. Therefore, caution needs to be used when surgeons employ bone dust as a bone graft substitute.