Usefulness of the preoperative thoracic inlet angle in comparison to the T1 slope for predicting cervical kyphosis after laminoplasty.

PURPOSE: Thoracic inlet angle (TIA) is a sagittal radiographic parameter with a constant value regardless of posture and is significantly correlated with the sagittal balance of the cervical spine. However, the practical use of TIA has not been studied. This study aimed to investigate the usefulness of the preoperative TIA for predicting the development of kyphotic deformity after cervical laminoplasty in comparison to the preoperative T1 slope (T1S). METHODS: A total of 98 patients who underwent cervical laminoplasty without preoperative kyphotic alignment were included (mean age, 73.7 years; 41.8% female). Radiography was evaluated before surgery and at the 2-year follow-up examination. The cervical sagittal parameters were measured on standing radiographs, and the TIA was measured on T2-weighted MRI in a supine position. Cervical alignment with a C2-C7 angle of ≥ 0° was defined as lordosis, and that with an angle of < 0° was defined as kyphosis. RESULTS: Postoperative kyphosis occurred in 11 patients (11.2%). Preoperatively, the kyphosis group showed significantly lower values in the T1S (23.5° vs. 30.3°, p = 0.034) and TIA (76.1° vs. 81.8°, p = 0.042). We performed ROC curve analysis to clarify the impact of the preoperative TIA and T1S on kyphotic deformity after laminoplasty. The optimal cutoff angles for TIA and T1S were 68° and 19°, respectively, with similar diagnostic accuracy. CONCLUSION: This study demonstrated the clinical utility of the preoperative TIA for predicting the risk of postoperative kyphotic deformity after cervical laminoplasty. These findings suggest the importance of the preoperative assessment of thoracic inlet alignment in cervical spine surgery.

Risk factors for early mortality in elderly patients with unstable isolated C2 odontoid fracture treated with halo-vest or surgery.

The aim of this study was to compare in-hospital mortality of three procedures -halo-vest immobilization, anterior spinal fixation (ASF), and posterior spinal fixation (PSF)- in the treatment of elderly patients with isolated C2 odontoid fracture. We extracted data for elderly patients who were admitted with C2 odontoid fracture and treated with at least one of the three procedures (halo-vest immobilization, ASF, or PSF) during hospitalization. We conducted a generalized propensity score-based matching weight analysis to compare in-hospital mortality among the three procedures. We further investigated independent risk factors for in-hospital death. The study involved 891 patients (halo-vest, n = 463; ASF, n = 74; and PSF, n = 354) with a mean age of 78 years. In-hospital death occurred in 45 (5.1%) patients. Treatment type was not significantly associated with in-hospital mortality. Male sex (odds ratio 2.98; 95% confidence interval 1.32-6.73; p = 0.009) and a Charlson comorbidity index of ≥ 3 (odds ratio 9.18; 95% confidence interval 3.25-25.92; p < 0.001) were independent risk factors for in-hospital mortality. In conclusion, treatment type was not significantly associated with in-hospital mortality in elderly patients with isolated C2 odontoid fracture. Halo-vest immobilization can help to avoid adverse events in patients with C2 odontoid fracture who are considered less suitable for surgical treatment.

Radiographic Predictors of Subaxial Subluxation After Atlantoaxial Fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to clarify preoperative radiographic predictors associated with the development of subaxial subluxation (SAS) after surgery. BACKGROUND: The incidence of atlantoaxial fusion for atlantoaxial instability has been increasing. SAS can develop after surgery despite atlantoaxial fusion with the optimal C1-C2 angle. We hypothesized that preoperative discordant angular contribution in the upper and subaxial cervical spine is associated with the occurrence of postoperative SAS. MATERIALS AND METHODS: Patients who underwent surgery for atlantoaxial instability with a minimum 5-year follow-up and control participants were included. The O-C2 angle, C2 slope (C2S), C2-C7 cervical lordosis (CL), and T1 slope (T1S) were measured. We focused on the angular contribution ratio in the upper cervical spine to the whole CL, and the preoperative C2/T1S ratio was defined as the ratio of C2S to T1S. RESULTS: Twenty-seven patients (SAS=11, no-SAS=16; mean age, 60.7 y old; 77.8% female; mean follow-up duration, 6.8 y) and 23 demographically matched control participants were enrolled. The SAS onset was at 4.7 postoperative years. Preoperatively, the O-C2 angle, C2-C7 CL, and T1S were comparable between the SAS, no-SAS, and control groups. The preoperative C2S and C2/T1S ratio were smaller in the SAS group than in the no-SAS or control group (C2S, 11.0 vs. 18.4 vs. 18.7 degrees; C2/T1S ratio, 0.49 vs. 0.77 vs. 0.78, P <0.05). The receiver operating characteristic curve analysis demonstrated that the C2/T1S ratio had higher specificity and similar sensitivity as a predictor of postoperative SAS than C2S (specificity: 0.90 vs. 0.87; sensitivity: 0.73 vs. 0.73). The estimated cutoff values of the C2S and C2/T1S ratio were 14 degrees and 0.58, respectively. CONCLUSIONS: The preoperative C2/T1S ratio was closely associated with postoperative SAS. Patients with a C2/T1S ratio <0.58 were at a high risk of SAS after atlantoaxial fusion. LEVEL OF EVIDENCE: Level 4.

Late-Onset Esophageal Perforation After Salvage Anterior Cervical Spine Surgery in a Patient With Systemic Sclerosis.

Systemic sclerosis (SSc) is a systemic, immune-mediated disease characterized by abnormal cutaneous and organ-based fibrosis that results in progressive organ dysfunction including the esophagus. We herein report our experience of a patient with SSc who underwent salvage anterior cervical spine surgery that led to late-onset esophageal perforation. A 57-year-old female had progressive cervical kyphosis after laminoplasty for cervical spondylotic myelopathy. We performed anterior cervical discectomy and fusion using a stand-alone cage. Despite prolonged use of a neck collar, migration of the anterior cage was noted three months after surgery. Rapid progression of kyphotic deformity prompted us to perform revision surgery of circumferential cervical correction. However, conventional posterior surgery was precluded due to the extremely poor condition of her neck, including severely sclerotic skin and atrophic muscles. To address this, she underwent a posterior fusion with the closed technique and C4-C5 corpectomy and bone grafting using a low-profile anterior plate. One year after the surgery, CT and routine upper gastrointestinal endoscopy (UGE) showed no evidence of esophagus injury. She remained asymptomatic thereafter. Over three years after her last surgery, however, follow-up CT incidentally revealed an abnormal air leak around the anterior plate. UGE demonstrated large esophagus perforation with the exposed metal plate. As she had already been on parenteral nutrition due to the disease progression of SSc, we decided not to remove the implant. Potential esophagus perforation after anterior cervical spine surgery, even years later, should be considered regardless of the patient's symptoms, such as chest pain and dysphagia. Spine surgeons need to be cognizant of the fragility of the esophagus, especially in patients with SSc. For patients with SSc, posterior reconstruction alone is recommended as a relatively safe option, even with a suboptimal skin condition.

Association Between Early Surgery and Postoperative Opioid Use in Patients With Lumbar Disc Herniation: A Propensity Score-Matching Analysis Using an Administrative Claims Database in Japan.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to investigate whether early surgery shortens the duration of opioid use in patients who underwent surgery with lumbar disc herniation. METHODS: We extracted patients who underwent surgery at least 2 weeks after they were diagnosed with lumbar disc herniation between April 2014 and May 2021. Opioid use after surgery was compared between patients who underwent surgery within 90 days (early surgery group) and 90 days or later (late surgery group). Propensity-score-matching analysis and multivariable Cox hazard regression analysis with a restricted cubic spline model were conducted to evaluate the association between the timing of surgery and termination of opioid use after surgery. RESULTS: A total of 1597 eligible patients were identified, with 807 (51%) in the early surgery group. In the propensity-score-matched cohort, the early surgery group had a significantly lower proportion of opioid use than the control group (28% vs 48%, percent difference -20%, P < .001). Multivariable Cox hazard regression analysis showed that early surgery was significantly associated with the earlier termination of opioid use (HR, 3.13; 95% CI, 1.97-4.97; P < .001). Restricted cubic spline model showed a monotonically decreased hazard ratio and decreased hazard ratio of .50 in patients who underwent surgery 111 days or later after the diagnosis. CONCLUSIONS: Early surgery, especially within 90 days, was associated with earlier opioid use termination after surgery. Regarding the duration of opioid use following surgery, surgical treatment may be preferable to perform within around 4 months after the diagnosis.

Impact of the preoperative nutritional status on postoperative kyphosis in geriatric patients undergoing cervical laminoplasty.

PURPOSE: This study aimed to determine the association of preoperative malnutrition with an increased risk of cervical kyphosis after laminoplasty in geriatric patients with cervical spondylotic myelopathy (CSM). METHODS: Geriatric patients who underwent cervical laminoplasty were included. Malnutrition was defined as a geriatric nutritional risk index < 98 before surgery. The C2-7 angle and the global alignment parameters were analyzed on standing radiographs. The postoperative kyphosis was defined as a C2-7 angle < 0° during a 2-year follow-up. RESULTS: Ninety patients without preoperative kyphotic alignment were enrolled (mean age, 73.5 years old; 41.1% female). Twenty-one patients (23.3%) had malnutrition status (74.2 years old). Preoperatively, the global alignment parameters were comparable between the malnutrition and normal nutrition groups (SVA, 43.3 mm vs. 42.4 mm; T1S, 29.7° vs. 28.4°; TPA, 21.4° vs. 17.8°), with no significant difference in the C2-7 angle (15.1° vs. 15.2°). At 2 years postoperatively, the malnutrition group showed a significantly lower C2-7 angle than the normal nutrition group (9.3° vs. 15.8°, P = 0.03). Postoperative kyphosis was more prevalent in the malnutrition group (33.3% vs. 7.2%, P = 0.005). The preoperative nutritional status and C2-7 angle were independent predictors of postoperative kyphosis. The predictive C2-7 angles differed by preoperative nutritional status (malnutrition group, 11°; normal nutrition group, 7°). CONCLUSION: Among geriatric CSM patients, preoperative malnutrition was closely associated with the increased occurrence of cervical kyphosis after laminoplasty. Our results underscore the importance of preoperative nutritional assessment and management in geriatric populations undergoing cervical spine surgery, as malnutrition is a perioperative modifiable risk factor.

Effect of Intraoperative Tranexamic Acid on Perioperative Major Hemorrhage Requiring Transfusion in Patients Undergoing Elective Spine Surgery: A Propensity Score-Matched Analysis Using a National Inpatient Database.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to examine whether the use of intravenous TXA in elective spine surgery is associated with reduced perioperative massive hemorrhage requiring transfusion. METHODS: We extracted all patients who underwent decompression with or without fusion surgery for the cervical, thoracic, and lumbar spine between April 2012 and March 2019. The primary outcome was the occurrence of massive hemorrhage requiring transfusion, defined as at least 560 mL of blood transfusion within 2 days of spine surgery or the requirement of additional blood transfusion from 3-7 days postoperatively. Secondary outcomes were the occurrence of thrombotic complications (pulmonary embolism, acute coronary syndrome, and stroke) and postoperative hematoma requiring additional surgery. RESULTS: We identified 83,821 eligible patients, with 9747 (12%) patients in the TXA group. Overall, massive hemorrhage requiring transfusion occurred in 781 (.9%) patients. Propensity score matching yielded 8394 pairs. In the matched cohort, the TXA group had a lower proportion of massive hemorrhage requiring transfusion than the control group (.7% vs 1.1%; P = .002). There was no significant difference in the occurrence of thrombotic complications and postoperative hematoma requiring additional surgery between both groups. The multivariable regression analysis also showed that the use of TXA was associated with significantly lower proportions of massive hemorrhage requiring transfusion (odds ratio, .62; 95% confidence interval, .43-.90; P = .012). CONCLUSIONS: In this analysis using real-world data, TXA use in elective spinal surgery was associated with reduced perioperative massive hemorrhage requiring transfusion without increasing thrombotic complications. LEVEL OF EVIDENCE: Prognostic Level Ⅲ.

The Association Between the Rotator Cuff Status and the Severity and Recovery of Weakness in the Shoulder Abductor Strength in a Case of Proximal Type Cervical Spondylotic Amyotrophy.

STUDY DESIGN: Case series study. OBJECTIVE: We aimed to clarify the prevalence of rotator cuff tear (RCT), and the association between RCT and the severity and prognosis in patients with proximal type cervical spondylotic amyotrophy (CSA). METHODS: We retrospectively analyzed 35 proximal type CSA patients who were treated conservatively. The following data was collected: age, rotator cuff status on MRI, manual muscle test (MMT) score of shoulder abductor and biceps brachii muscles both at the first visit and final follow-up. We investigated the prevalence of RCT and the association between the rotator cuff status, and the severity and recovery of upper extremity weakness in patients with proximal type CSA. RESULTS: Of the 35 patients, 21 had an RCT on MRI, indicating that the prevalence of RCT in patients with proximal type CSA was 60%. An age-adjusted analysis showed that the presence of RCT was significantly associated with the MMT score of the shoulder abductor muscles both at the first visit and at the final follow-up. The presence of RCT was significantly associated with the recovery of the shoulder abductor muscles. The size of the RCT was negatively correlated with the MMT score of the shoulder abductor muscles at the final follow-up. The size of the RCT was independently correlated with the change of the MMT score of the shoulder abductor muscles. CONCLUSION: RCT was detected in >50% in patients with proximal type CSA, and the presence and severity of RCT can be used as prognostic factors for proximal type CSA patients who are treated conservatively.

Increased Cervical Spinal Instability is Associated With the Development of Proximal-type Cervical Spondylotic Amyotrophy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: We aimed to clarify the clinical relationship between the etiology of proximal-type cervical spondylotic amyotrophy (CSA) and cervical sagittal alignment and instability. SUMMARY OF BACKGROUND DATA: Although several researchers have discussed hypotheses regarding the etiology of CSA, the trigger and mechanism underlying the onset remain unclear. METHODS: We retrospectively analyzed 52 proximal-type CSA patients (CSA group) and 60 control patients (Control group). The following data were collected: age; sex; cervical lordosis (CL); T1 slope (TS); TS-CL; C2-7 sagittal vertical axis (SVA) on x-ray in the neutral position; flexion angle; extension angle and range of motion (ROM) of C3/4, C4/5 and C5/6; and C3/4, C4/5 and C5/6 instability (translation of >3 mm for adjacent segmental segments) on dynamic x-ray. RESULTS: Compared with the Control group, the CSA group was associated with an older age (mean age, 67.6 vs. 61.1 years' old, P= 0.029) and male sex (78.8% vs. 50.0%, P= 0.002). In the CSA group, the radiographic parameters showed smaller C4/5 and C5/6 extension angles and C5/6 ROM values and a greater C3/4 flexion angle than the Control group. Furthermore, compared with the Control group, the CSA group was associated with C3/4 instability (13.5% vs. 3.3%, P= 0.049) and C4/5 (21.2% vs. 3.3%, P = 0.003). A logistic regression analysis, with adjusting for the age and sex, showed that the C3/4 flexion angle (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.08- 1.40, P =0.002), C3/4 instability (OR, 7.3; 95% CI 1.25-42.96, P =0.027) and C4/5 instability (OR, 8.1; 95% CI, 1.56-42.19, P = 0.012) were independent risk factors of CSA. CONCLUSION: This study suggested that a wide C3/4 flexion angle and high C3/4 or C4/5 spinal instability were closely associated with the etiology of proximal-type CSA.

Angiomatous Meningioma in the Craniocervical Junction.

INTRODUCTION: Spinal angiomatous meningioma arising in the craniocervical junction has not been reported. Case Presentation. A 68-year-old man presented to our hospital with pain in the back and left leg. He showed slight motor weakness in his upper extremities. Magnetic resonance imaging revealed a mass with marked enhancement in the craniocervical junction. Computed tomography angiography showed feeding vessels arising from the right vertebral artery. Preoperative embolization of the feeding vessels was performed to reduce intraoperative bleeding. Gross total resection of the tumor was achieved by debulking and piecemeal resection. The tumor attachment to the dura mater was also resected (Simpson grade 1 resection). A histopathological examination confirmed the diagnosis of an angiomatous meningioma. The patient's symptoms improved shortly after surgery. CONCLUSIONS: We achieved gross total resection of spinal angiomatous meningioma arising in the craniocervical junction. A preoperative evaluation and embolization of the feeding arteries may help prevent massive intraoperative bleeding.