Characteristics of Screw Perforation and Screw Loosening in Atlantoaxial Transarticular Fixation Using a Preoperative Computed Tomography-Based Navigation System

BACKGROUND

Atlantoaxial transarticular fixation, also called the Magerl technique, is said to be the most robust biomechanical method of fixation of the atlantoaxial vertebrae. However, the procedure carries a risk of spinal cord and vertebral artery injury during the insertion process, especially in patients with a high-riding vertebral artery. In this study, a computed tomography (CT)-based navigation system was used for preoperative planning and insertion. This investigation sought to determine the rate and direction of screw perforation as well as the incidence of screw loosening in computer-assisted atlantoaxial transarticular fixation.

METHODS

Sixty patients (31 men and 29 women; mean ± SD age: 65.3 ± 19.6 years) who received atlantoaxial transarticular screw insertion with preoperative CT navigation were analyzed. We investigated screw position and loosening by CT at the final follow-up.

RESULTS

Of the 108 screws inserted, the rate of Grade 2 or higher perforation was 4.6% (5/108). Nine of 81 (11.1%) screws inserted into the 44 patients who were followed for at least 6 months showed loosening. Logistic regression analysis revealed that unilateral insertion (odds ratio: 8.50, 95% confidence interval: 1.53-47.2, P = 0.014) was significantly associated with the incidence of screw loosening.

CONCLUSIONS

The screw perforation rate of Grade 2 or higher in computer-assisted atlantoaxial transarticular screw fixation was 4.6%, with comparable frequencies of perforation direction. Unilateral insertion was a significant independent factor associated with screw loosening, which occurred in 11.1% of insertions.

CLINICAL RELEVANCE

Spine surgeons should follow up with patients with caution because screws with unilateral insertion are prone to loosening.

LEVEL OF EVIDENCE: 4

Real-World Effectiveness of Gelatin-Thrombin Matrix Sealant on Blood Loss in Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion: An Interrupted Time Series Study

STUDY DESIGN

Retrospective cohort study with interrupted time series analysis.

OBJECTIVE

To examine the clinical effectiveness of gelatin-thrombin matrix sealant (GTMS) on blood loss reduction after adolescent idiopathic scoliosis (AIS) surgery.

SUMMARY OF BACKGROUND DATA

The real-world effectiveness of GTMS on blood loss reduction in AIS surgery has not been determined.

PATIENTS AND METHODS

The medical records of patients receiving AIS surgery were retrospectively collected during a period before GTMS approval at our institution (January 22, 2010-January 21, 2015) as well as during a postintroduction period (January 22, 2015-January 22, 2020). The primary outcomes were intraoperative blood loss, drain output over 24 hours, and total blood loss (intraoperative blood loss + drain output over 24 h). Interrupted time series analysis using a segmented linear regression model was used to estimate the effect of GTMS on blood loss reduction.

RESULTS

A total of 179 AIS patients [mean age (range): 15.4 (11-30) yr; 159 females and 20 males; 63 preintroduction patients and 116 postintroduction patients] were included. After its introduction, GTMS was used in 40% of cases. Interrupted time series analysis revealed changes of -340 mL (95% CI: -649 to -31, P = 0.03) for intraoperative blood loss, -35 mL (95% CI: -124 to 55, P = 0.44) for drain output over 24 hours, and -375 mL (95% CI: -698 to -51, P = 0.02) for total blood loss.

CONCLUSIONS

The availability of GTMS was significantly associated with reduced intraoperative and total blood loss in AIS surgery. GTMS use as needed is recommended to control intraoperative bleeding in the setting of AIS surgery.

LEVEL OF EVIDENCE

3.

Impact of osteosclerosis on cervical pedicle screw insertion using preoperative CT-based navigation

PURPOSE

Preoperative computed tomography (CT)-based navigation is used for cervical pedicle screw (CPS) insertion to mitigate the risk of spinal cord and vertebral artery injury. In vertebrae with osteosclerosis due to degeneration or other factors, however, probing may not proceed easily, with difficulty creating the CPS insertion hole. This study investigated the impact of osteosclerosis on the accuracy of CPS insertion.

METHODS

A total of 138 patients with CPS inserted at the C3-C7 level using preoperative CT navigation were retrospectively analyzed. Pre- and postoperative CT was employed to investigate screw position and Hounsfield unit (HU) values at the lateral mass to evaluate the degree of osteosclerosis in the CPS insertion pathway.

RESULTS

Among 561 CPS insertions, the Grade 3 perforation rate was 1.8%, and the Grade 2 or higher perforation rate was 8.0%. When comparing insertions with and without CPS perforation, HU values were significantly higher in the perforation group (578 ± 191 vs. 318 ± 191, p < 0.01). The frequency of CPS insertion into the mid-cervical spine was also significantly greater in the perforation group (68.9% vs. 62.5%, p < 0.01). Logistic regression analysis revealed that a high HU value at the lateral mass (odds ratio 1.09, 95% confidence interval: 1.07-1.11, p < 0.01) was a significant independent factor associated with CPS deviation.

CONCLUSIONS

The screw perforation rate of Grade 2 or higher in CPS insertion using preoperative CT-based navigation was 8.0%. Since osteosclerosis was an independent factor related to CPS deviation, additional care may be required during insertion into affected vertebrae.

Impact of the COVID-19 pandemic on the incidence of surgical site infection after orthopaedic surgery: an interrupted time series analysis of the nationwide surveillance database in Japan

BACKGROUND

During the COVID-19 pandemic, hygiene awareness was increased in communities and hospitals. However, there is controversy regarding whether such circumstances affected the incidence of surgical site infections (SSIs) in the orthopaedic surgical field.

AIM

To examine the impact of the COVID-19 pandemic on the incidence of SSIs after orthopaedic surgery.

METHODS

The medical records of patients having undergone orthopaedic surgery were extracted from the nationwide surveillance database in Japan. The primary outcomes were the monthly incidences of total SSIs, deep or organ/space SSIs, and SSIs due to meticillin-resistant Staphylococcus aureus (MRSA). Interrupted time series analysis was conducted between pre-pandemic (January 2017 to March 2020) and pandemic (April 2020 to June 2021) periods.

RESULTS

A total of 309,341 operations were included. Interrupted time series analysis adjusted for seasonality showed no significant changes in the incidence of total SSIs (rate ratio 0.94 and 95% confidence interval 0.98-1.02), deep or organ/space SSIs (0.91, 0.72-1.15), or SSIs due to MRSA (1.07, 0.68-1.68) along with no remarkable slope changes in any parameter (1.00, 0.98-1.02; 1.00, 0.97-1.02; and 0.98, 0.93-1.03, respectively).

CONCLUSIONS

Awareness and measures against the COVID-19 pandemic did not markedly influence the incidence of total SSIs, deep or organ/space SSIs, or SSIs due to MRSA following orthopaedic surgery in Japan.

Reduction in CT scan number with the reference frame middle attachment method in intraoperative CT navigation for adolescent idiopathic scoliosis

PURPOSE

Elucidate whether it is preferable to use the reference frame (RF) middle attachment (RFMA) method over the edge of the planned pedicle screw (PS) insertion area for RF placement in the surgery for adolescent idiopathic scoliosis (AIS) with intraoperative computed tomography (CT) navigation.

METHODS

Eighty-six consecutive patients (76 female and 10 male; mean age: 15.9 years) with AIS who underwent posterior spinal fusion using intraoperative CT navigation were enrolled. The group with the RF placed at the most distal part of the CT scan range was defined as the distal group (Group D), with other placements classified into the middle group (Group M). PS perforation rate and surgical outcome were compared between the groups.

RESULTS

There was no significant difference in perforation rate between Group M and Group D (3.4% vs. 3.0%, P = 0.754). The mean ± standard deviation number of instrumented vertebrae at the first CT scan was significantly higher in Group M (8.2 ± 1.2 vs. 6.3 ± 1.2, P < 0.001), while mean blood loss was significantly lower (266 ± 185 mL vs. 416 ± 348 mL, P = 0.011). The frequency of needing a second CT scan for PS insertion was significantly lower in Group M (38% vs. 69%, P = 0.04).

CONCLUSION

The RFMA method in thoracic scoliosis surgery for AIS with intraoperative CT navigation could significantly decrease the number of CT scans and blood loss while maintaining a comparable PS perforation rate to RF placement at the distal end of the planned PS insertion range.

Reliability and validity of gait dynamic balance assessment in adult spinal deformity patients using a two-point trunk motion measuring device

BACKGROUND CONTEXT

Adult spinal deformity (ASD) patients often complain of walking discomfort. However, dynamic balance evaluation methods of gait in ASD have not been well established.

DESIGN

Case series study.

PURPOSE

Characterize the gait of ASD patients using a novel two-point trunk motion measuring device.

PATIENT SAMPLE

Sixteen ASD patients scheduled for surgery and 16 healthy control subjects.

OUTCOME MEASURES

Trunk swing width and track length of the upper back and sacrum.

METHODS

Gait analysis was performed using a two-point trunk motion measuring device on 16 ASD patients and 16 healthy control subjects. Three measurements were taken for each subject, and the coefficient of variation was determined to compare measurement accuracy between the ASD and control groups. Trunk swing width and track length were measured in three dimensions for comparisons between the groups. The relationship among output indices, sagittal spinal alignment parameters, and quality of life (QOL) questionnaire scores was examined as well.

RESULTS

No significant difference was found for the precision of the device between the ASD and control groups. Compared with controls, the walking style of ASD patients tended to have larger right-left swing of the trunk (+14.0 cm and +23.3 cm at the sacrum and upper back, respectively), larger horizontal plane movement of the upper body (+36.4 cm), less vertical movement (-5.9 cm and -8.2 cm up-down swing at the sacrum and upper back, respectively), and longer gait cycle (+0.13 sec). Regarding QOL in ASD patients, greater right-left/front-back swing of the trunk, greater movement in the horizontal plane, and longer gait cycle were associated with lower QOL scores. Conversely, greater vertical movement was associated with higher QOL.

CONCLUSIONS

ASD patients had unique gait characteristics, the intensity of which were associated with diminished QOL. The two-point trunk motion measuring device may be reliable and useful for the clinical assessment of balance during gait in ASD patients.

Frequency and Associated Factors of Postoperative Wound Dehiscence in Posterior Cervical Spine Surgery

OBJECTIVE

Wound dehiscence after cervical spine surgery is a well-known complication that can be a challenge for spine surgeons to manage, especially in cases of exposed implants. However, few studies have focused primarily on this phenomenon in cervical spine surgery to date. This investigation sought to determine the frequency of wound dehiscence following posterior cervical spine surgery and identify patient-based risk factors.

METHODS

The medical data of 405 consecutive patients (290 male and 115 female; mean age: 68.9 years) who underwent posterior cervical spine surgery were retrospectively examined. Logistic regression models were employed to examine the prevalence, characteristics, and risk factors of postoperative wound dehiscence.

RESULTS

We observed that 5.2% of cervical spine surgery patients experienced procedural postoperative wound dehiscence. In comparisons of dehiscence and non-dehiscence groups, significant differences were found for posterior instrumented fusion (81.0% vs. 45.3%; P < 0.01), extended T1 fusion (57.1% vs. 12.8%; P < 0.01), occipitocervical fusion (19.0% vs. 6.2%; P = 0.048), fused intervertebral levels (4.0 vs. 1.5; P < 0.01), surgical time (246 minutes vs. 165 minutes; P < 0.01), blood loss volume (228 mL vs. 148 mL; P = 0.023), and dialysis (14.3% vs. 1.8%; P = 0.011). Multivariate analysis identified extended T1 fusion and dialysis to be significantly associated with wound dehiscence with odds ratios of 5.82 and 10.70, respectively.

CONCLUSIONS

The observed frequency of postoperative wound dehiscence in cervical spine surgery was 5.2%. As extended T1 fusion and dialysis may increase the risk of dehiscence after surgery, patients who display such risk factors may require additional observation and care.

Tips and pitfalls to improve accuracy and reduce radiation exposure in intraoperative CT navigation for pediatric scoliosis: a systematic review

BACKGROUND CONTEXT

An increasing number of medical centers are adopting an intraoperative computed tomography (iCT) navigation system (iCT-Navi) to provide three-dimensional navigation for pediatric scoliosis surgery. While iCT-Navi has been reported to provide higher pedicle screw (PS) insertion accuracy, it may also result in higher radiation exposure to the patient. What innovations and studies have been introduced to reduce radiation exposure and further improve PS insertion?

PURPOSE

Evaluate the level of evidence and quality of papers while categorizing the tips and pitfalls regarding pediatric scoliosis surgery using iCT-Navi. Compare iCT-Navi with other methods, including preoperative CT navigation.

STUDY DESIGN

Systematic review.

PATIENT SAMPLE

Articles on pediatric scoliosis surgery with iCT-Navi published through to June 2022.

OUTCOME MEASURES

PS perforation rate and patient intraoperative radiation dose.

METHODS

Following PRISMA guidelines, the Cochrane Library, Google Scholar, and PubMed databases were searched for articles satisfying the criteria of iCT-Navi use and pediatric scoliosis surgery. The level of evidence and quality of the articles meeting the criteria were evaluated according to the guidelines of the North American Spine Society and American Academy of Orthopedic Surgeons, respectively. The articles were also categorized by theme and summarized in terms of PS insertion accuracy and intraoperative radiation dose. The origins and characteristics of five major classification methods of PS perforation grade were summarized as well.

RESULTS

The literature search identified 811 studies, of which 20 papers were included in this review. Overall, 513 pediatric scoliosis patients (381 idiopathic, 44 neuromuscular, 39 neurofibromatosis type 1, 28 congenital, 14 syndromic, seven other) were evaluated for PS perforations among 6,209 iCT-Navi insertions. We found that 232 (3.7%) screws were judged as major perforations (G2 or G3), 55 (0.9%) screws were judged as dangerous deviations (G3), and seven (0.1%) screws were removed. There were no reports of neurovascular injury caused by PSs. The risk factors for PS perforation included more than six vertebrae distance from the reference frame, more than nine consecutive insertions, upper thoracic level, thinner pedicle, upper instrumented vertebra proximity, short stature, and female. The accuracy of PS insertion did not remarkably decrease when the radiation dose was reduced to 1/5 or 1/10 by altering the iCT-Navi protocol.

CONCLUSIONS

iCT-Navi has the potential to reduce PS perforation rates compared with other methods. The use of low-dose radiation protocols may not significantly affect PS perforation rates. Although several risk factors for PS perforation and measures to reduce radiation dose have been reported, the current evidence is limited by a lack of consistency in classifying PS perforation and evaluating patient radiation dose among studies. The standardization of several outcome definitions is recommended in this rapidly developing field.

Postoperative Residual Coronal Decompensation Inhibits Self-image Improvement in Adolescent Patients with Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort study.

PURPOSE

This study aimed to evaluate the relationship between C7 plumb line (C7PL) decompensation and the Scoliosis Research Society (SRS) 22-item patient questionnaire scores, including those related to self-image, preoperatively and 2 years after surgery.

OVERVIEW OF LITERATURE

In the surgical treatment of adolescent idiopathic scoliosis (AIS), inferior trunk balance caused by C7PL decompensation can negatively affect patients' quality of life. However, there are few reports in the literature that describe or clarify how postoperative trunk imbalance affects each SRS-22 domain, including self-image domain scores.

METHODS

A total of 120 patients with AIS who underwent posterior spinal fusion from August 2006 to March 2017 at our facility and were followed up for 2 years or more were included. Radiological parameters were measured on whole-spine anteroposterior and lateral radiographs. Revised SRS-22 (SRS-22r) values were also recorded. Coronal trunk imbalance was defined as a deviation of ≥2.0 cm between the C7PL and the central sacral vertical line. Patients with and without coronal trunk imbalance at 2 years after surgery were defined as D (+) (decompensation type) and D (-), respectively. Mean SRS-22r values, including function, pain, self-image, mental health, and subtotal were compared between the D (+) and D (-) groups. Logistic regression analysis was performed to detect the preoperative factors related to D (+) using predictors, including curve type, maximum Cobb angle, and coronal trunk imbalance.

RESULTS

At 2 years after surgery, the D (+) group had a significantly lower self-image in the domain of SRS-22r scores compared with the D (-) group. Preoperative coronal trunk imbalance was significantly related to D (+) but not to significant changes in the postoperative SRS-22 score in any of the SRS-22 domains.

CONCLUSIONS

Postoperative C7PL deviation lowers the self-image in patients with AIS. Patients with preoperative coronal trunk imbalance were significantly more likely to be D (+).

A challenging case of lumbar vertebral burst fracture with alcohol withdrawal delirium: A case report

BACKGROUND

Delirium tremens is a symptom of alcohol withdrawal syndrome that occurs 48 to 96 hours after the last drink in 5% of withdrawing patients.

METHODS

This report describes the clinical progression of a case of lumbar vertebral burst fracture with alcohol withdrawal delirium that was difficult to manage.

RESULTS

A 47-year-old man was rushed to our hospital complaining of lumbar back pain and numbness in both lower extremities resulting from a 6-m fall during civil engineering work. Computed tomography (CT) revealed a L1 burst fracture with a highly protruding bone fragment in the spinal canal. Magnetic resonance imaging disclosed significant compression of the conus and intramedullary signal changes. We immediately performed posterior spinal fusion and vertebroplasty using instrumentation. On the 4th postoperative day, he became severely agitated, as diagnosed as having delirium tremens related to alcohol withdrawal syndrome, and soon began appropriate medication with diazepam. Although his symptoms persisted until 6 days postoperatively, follow-up CT detected no evidence of screw loosening or breakage.

CONCLUSION

We encountered a patient with severe delirium tremens developing several days after thoraco-lumbar fusion surgery. Prompt internal fixation successfully treated the spinal injury and prevented neurological damage. It may also be necessary to consider treatment strategies for patients with a background of heavy alcohol consumption in consideration of delirium tremens and other symptoms of alcohol withdrawal.

Surgical results for cervical spondylotic myelopathy with inconsistent between deep tendon reflex findings and magnetic resonance imaging findings

BACKGROUND

To evaluate the surgical results of patients with cervical spondylotic myelopathy (CSM) with inconsistency between deep tendon reflex findings and cervical magnetic resonance imaging (MRI) findings and to analyze the differences between patients with good and poor surgical outcomes.

METHODS

We evaluated 50 subjects with CSM (30 males, 20 females; mean age: 70.4 years) who underwent posterior surgery and were followed for at least 1 year postoperatively. Matched CSM was defined as a consistent preoperative neurological pattern determined by deep tendon reflex and cervical MRI T2-weighted high-signal intramedullary area or stenosis in the most cranial compression levels. A lack of consistency was classified as unmatched CSM. Recovery rate (RR) according to Japanese Orthopaedic Association (JOA) scoring preoperatively and at 1 year postoperatively were compared between the groups.

RESULTS

The matched and unmatched CSM group included 27 subjects (13 males, 14 females; mean age: 68.2 years) and 23 subjects (17 males, 6 females; mean age: 72.8 years), respectively. RR was significantly higher in the matched CSM group (56.1 ± 3.7 % vs 36.8 ± 2.7 %; p = 0.002). Unmatched CSM was significantly associated with a lower RR independently of sex, patient age, surgical procedure, preoperative JOA score, diagnosis levels, and complication of diabetes.

CONCLUSIONS

Postoperative JOA score RR was significantly diminished among unmatched CSM patients comprising of 46% of cases. Some patients with unmatched CSM had multiple levels of spinal canal stenosis, foraminal stenosis, and peripheral neuropathy, suggesting that surgical results were poorer than those of matched CSM.

Impact of Physical Flexibility Changes on Respiratory Function after Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis Surgery

Introduction

Corrective scoliosis surgery in patients with adolescent idiopathic scoliosis (AIS) increases thoracic volume but does not improve respiratory function (RF). This study evaluates the effect of physical flexibility (PF) improvement after scoliosis surgery on RF.

Methods

This study reviewed the records of 61 consecutive patients with AIS (56 female and 5 male; mean±standard deviation age: 14.8±2.2 years, range: 11-20 years) who had undergone posterior spinal fusion (PSF) of the thoracic curve. PF evaluated as finger-floor distance (FFD) was measured preoperatively and one year after surgery. After dividing the cohort into the PF improvement group and the PF nonimprovement group, RF changes at two years postoperative were statistically compared. Using logistic regression analysis, we evaluated the impact of a PF improvement on % forced vital capacity (%FVC) two years after surgery.

Results

The rate of patients with increased FVC, %FVC, and forced expiratory volume 1.0 second two years after surgery was 79%, 51%, and 80%, respectively. The PF improvement group exhibited a significantly higher gain in %FVC versus the PF nonimprovement group (P=0.043). Moreover, PF improvement significantly prevented a %FVC decrease (odds ratio 8.43, 95% confidence interval 1.92-59.70; P<0.001), with an adjusted odds ratio of 11.86 (P<0.001).

Conclusions

Patients with diminished PF after PSF for AIS may be less likely to achieve postoperative %FVC improvement. As increased postsurgical %FVC had a positive effect on physical function, treatment strategies that focus on maintaining and increasing PF are desirable from an RF viewpoint.

How much residual deformity is acceptable according to SRS-22r and satisfaction scores after posterior spinal fusion for Lenke type 1 and 2 curves in adolescent idiopathic scoliosis?

OBJECTIVE

In recent years, it has become possible to predict postoperative correction and residual deformity in adolescent idiopathic scoliosis (AIS) surgery based on the technique used and extent of fixation. However, the recommended degree of correction has not yet been established. In this study, the authors aimed to clarify the extent to which a residual postoperative deformity would be acceptable according to Scoliosis Research Society (SRS)-22r and satisfaction scores after AIS surgery.

METHODS

Overall, 92 patients who underwent posterior spinal fusion for Lenke type 1 or 2 AIS were retrospectively included. The Patient Acceptable Symptom State (PASS) cutoff values for each SRS-22r domain were calculated using receiver operating characteristic (ROC) curves to obtain predictive values of treatment satisfaction 2 years after surgery. Multivariate logistic regression analysis was performed with deformity parameters and demographic data as explanatory variables, and achieving the PASS cutoff value of each SRS-22r domain and treatment satisfaction were objective variables. Cutoff values were calculated using ROC analysis.

RESULTS

The PASS cutoff values for SRS-22r domains were 3.69 (area under the ROC curve [AUC] 0.86) for self-image, 4.25 (AUC 0.82) for mental health, and 4.22 (AUC 0.82) for the subtotal. The residual main thoracic Cobb angle was not remarkably related to SRS-22r or treatment satisfaction. The residual thoracolumbar/lumbar (TL/L) Cobb angle was significantly associated with treatment satisfaction, with a cutoff value of 12.5° (AUC 0.75). The parameters of deformity that were significantly associated with achieving the PASS cutoff value for self-image were the TL/L Cobb angle and main thoracic apical vertebral translation, although their respective AUCs were < 0.7.

CONCLUSIONS

In patients with Lenke type 1 and 2 AIS, the residual postoperative TL/L Cobb angle was significantly associated with achieving the PASS cutoff values for self-image and treatment satisfaction. Satisfaction with treatment was more likely when the TL/L Cobb angle was ≤ 12.5°.

Comparison of differences and random errors in pedicle diameter measurements between MRI and CT: observational study of 315 pedicles in Lenke type 1 adolescent idiopathic scoliosis patients

BACKGROUND CONTEXT

Posterior spinal fusion with pedicle screws is commonly used for the treatment of adolescent idiopathic scoliosis (AIS). To reduce radiation exposure, methods other than computed tomography (CT) are desirable for preoperative determination of pedicle diameter.

PURPOSE

Investigate the differences between magnetic resonance imaging (MRI) and CT measurements of pedicle diameter.

STUDY DESIGN

Cross-sectional research.

PATIENT SAMPLE

Twenty-one AIS Lenke type 1 patients (19 female and 2 males, mean age at surgery: 15.4 years) who underwent posterior spinal fusion between April 2009 and October 2019.

OUTCOME MEASURES

Gap between CT and MRI pedicle diameters.

METHODS

The inner and outer diameters of the right and left pedicles from T1 to L3 were measured separately by two spine surgeons for statistical comparisons.

RESULTS

The respective minimum and maximum CT-MRI values were -3.7 mm and 4.7 mm for inner diameter and -4.6 mm and 5.3 mm for outer diameter. Regarding inter-examiner error, the probability of a 2 mm difference in measurement was less than 5% for both modalities. The probability of a 1 mm difference was also less than 5%, and that of a 3 mm or more difference was 2.1% for the inner diameter and 2.9% for the outer diameter. Whereas low body weight was significantly associated with measurement differences, pedicle laterality was not.

CONCLUSIONS

MRI does not have the reliability to measure pedicle size in AIS patients at present. However, with advancements in image processing technology, the accuracy of pedicle size measurement by MRI may soon improve.

A case of adult-onset Grisel's syndrome

Aim: Grisel's syndrome is a non-traumatic subluxation of the atlanto-axial joint that occurs after infection or inflammation in the otolaryngological area, primarily in children.Method: This report describes the clinical characteristics of an extremely rare case of adult-onset Grisel's syndrome.Result: A 77-year-old woman presented with neck and bilateral shoulder pain and stiffness. Her temperature was 37.6 °C. Blood testing revealed a mildly elevated inflammatory response, although blood cultures were negative. Computed tomography (CT) showed atlanto-axial subluxation and joint destruction. T2-weighted magnetic resonance imaging (MRI) displayed high signals in the soft tissues in the anterior space of the atlas and axis, posterior wall of the pharynx, and interspinous ligament, indicating spinal cord compression at the C1 level. Differential diagnoses of inflammation and diseases causing atlanto-axial subluxation included rheumatoid arthritis, amyloidosis, pyogenic spondylitis due to posterior pharyngeal abscess, and crowned dens syndrome. After the systematic elimination of each condition, we considered Grisel's syndrome and began non-surgical treatment with intravenous antibiotics and a Philadelphia neck collar. Her inflammatory response and neck pain gradually decreased. Six months later, there was no progression of instability. She was able to walk unaided and live normally with the use of a neck collar as needed.Conclusion: Grisel's syndrome occurs predominantly in children, but can also afflict adults. Since early diagnosis and treatment can improve symptoms in some cases and prevent progressive atlanto-axial instability, prompt evaluation of the atlanto-axial joint using CT or MRI is advised in patients with neck pain and limited range of motion.

Cervical myelopathy due to amyloid deposition with accompanying cardiac abnormalities

BACKGROUND

Amyloidosis is a rare group of diseases in which fibrillar amyloid proteins are deposited in systemic organs to result in functional disorder. However, amyloidosis affecting the cervical spine is very rare. We herein describe a case of systemic amyloidosis including a combination of cervical myelopathy with amyloid deposition and cardiac dysfunction due to cardiac amyloidosis.

CASE PRESENTATION

An 86-year-old man with cervical myelopathy accompanied with cardiac dysfunction due to cardiac amyloidosis underwent posterior cervical laminectomy from C3 to C4. We were able to identify the patient's cardiac amyloidosis and significant cardiac dysfunction before surgery and manage his perioperative treatment successfully. Preoperative cervical computed tomography (CT) showed multiple fine calcifications below the lamina, which were later confirmed by pathological analysis as amyloid deposition.

CONCLUSIONS

This is a relatively rare report of systemic amyloidosis including a combination of cervical myelopathy with amyloid deposition and cardiac dysfunction from cardiac amyloidosis. CT findings of multiple fine calcifications suggest the possibility of amyloidosis and may warrant further examination of cardiac function.

Frequency of Change in Assessment from Bony Union to Nonunion after Lumbar Interbody Fusion: A Multicenter Study

Introduction

Assessments of early postoperative bony union after posterior lumbar interbody fusion via computed tomography (CT) have revealed cases in which interbody fixation by bony union resulted in nonfusion due to bone absorption. The apparent bone union state reverted to a nonunion state several months later, exhibiting a so-called “fake union” phenomenon. Additionally, few reports have evaluated the effect of teriparatide on bony union. The present study aimed to evaluate the frequency of change in assessment from fusion to nonfusion in the postoperative follow-up of lumbar interbody fusion, compare the late postoperative bony union rates in groups with or without early postoperative fusion, and examine the effect of postoperative teriparatide in those groups.

Methods

Sixty-nine subjects enrolled from multiple hospitals were prospectively evaluated following single-level lumbar interbody fusion. The patients were randomly allocated into treatment with or without weekly postoperative teriparatide. The subjects were then classified as having bony union or nonfusion at 2 months postoperatively, and fusion rates at 6 months were compared. For the evaluation of bony union, blinded radiological examinations were performed via CT. Additional comparisons were made according to teriparatide use.

Results

The rate of nonunion at 6 months postoperatively in patients with fusion at 2 months postoperatively was 27.8%. Among subjects with bony union at 2 months postoperatively, the fusion rate at 6 months in those who received teriparatide was 93.3% (p=0.027) versus 57.1% in those who did not.

Conclusions

The rate of nonunion at 6 months postoperatively in patients exhibiting union at 2 months after surgery was 27.8%. Postoperative weekly teriparatide treatment significantly reduced the rate of fake union.

A Novel Technique for Cervical Microscopic Foraminotomy Utilizing Spinous Process Splitting: Microscopic Mini-Open Foraminotomy

Introduction

In this study, we present “microscopic mini-open foraminotomy (MicroMOF)” as a new, less invasive method for posterior cervical foraminotomy.

Technical Note

Using surgical microscope guidance, the spinous process is hemi-split, and the posterior muscle is detached from the laminar subperiosteal surface. Bony resection is then performed obliquely from medial posterior to lateral anterior under lateral-tilted surgical field exposure. MicroMOF has been performed successfully for cervical radiculopathy and cervical spondylotic amyotrophy, which achieved postoperative symptom improvement with few complications.

Conclusions

The novel MicroMOF foraminotomy technique has been found to protect the nerve root and vertebral artery and help preserve muscle and cervical facet joint bone.

Pre-operative angle of trunk rotation in prone position estimates postoperative correction results

This study investigated whether postoperative rotational deformity in adolescent idiopathic scoliosis patients could be predicted by prone-position pre-operative angle of trunk rotation (ATR).Surgical rib hump correction is performed with the patient in a prone position. However, the association between pre-operative ATR in the prone position and postoperative ATR results is unknown.Thirty-four consecutive patients who underwent skip pedicle screw fixation for Lenke type 1 or 2 adolescent idiopathic scoliosis were retrospectively reviewed. All subjects were followed for a minimum of 1 year. ATR measurements were taken for the standing-flexion position with a scoliometer before surgery and at 1 year afterward. Pre-operative measurements were also taken for the prone position. Correlations between pre- and postoperative ATR were calculated by means of Pearson correlation coefficient. Associations between the correction angle from the standing-flexion position to prone position and postoperative standing-flexion correction angle were determined by linear regression analysis.Pre- and postoperative ATR for the standing-flexion position showed a moderate association (r = 0.64, P < .01). A similar correlation was seen for pre-operative prone-position ATR and postoperative standing-flexion ATR (r = 0.56, P < .01). In linear regression analysis, there was significant proportional error between the correction angle from the standing-flexion position to prone position and postoperative standing-flexion correction angle (β = 0.40, P < .01).In conclusion, pre-operative ATR in either standing-flexion or prone position and postoperative standing-flexion ATR displayed moderate associations. Linear regression analysis revealed that ATR correction angle could be estimated by calculating the correction gains of 0.4° per 1° of correction angle in the prone position.

Comparison of fusion versus non-fusion surgery for retro-odontoid pseudotumor with atlanto-axial subluxation

Background

Due to the limited number of reports comparing posterior fusion with posterior decompression alone for retro-odontoid pseudotumor, there remains no consensus on treatment preference, especially in older patients. This study compared posterior fusion (with or without additional decompression) with posterior decompression alone for treating spinal cord pressure from non-inflammatory retro-odontoid pseudotumor with atlanto-axial subluxation (AAS).

Methods

Forty-one patients (27 male and 14 female; mean age, 73.0 ± 11.4 years) who underwent either posterior cervical fusion or decompression alone for the treatment of non-inflammatory retro-odontoid pseudotumor with AAS and were observed for more than 1 year between September 2009 and July 2019 were enrolled. Thirty-two patients (23 male and 9 female; mean age: 71.8 ± 10.9 years) received posterior fusion surgery (fusion group) and 9 patients (4 male and 5 female; mean age: 77.2 ± 12.5 years) underwent decompression alone (non-fusion group). We compared pre- and postoperative Japanese Orthopaedic Association (JOA) scores and preoperative cervical alignment parameters between the groups.

Results

In the fusion group, the mean preoperative JOA score was significantly improved from 9.0 ± 3.2 points to 11.7 ± 3.2 points at the final follow-up (p = 0.0002). Similarly in the non-fusion group, the mean preoperative and final follow-up JOA scores were 8.2 ± 3.5 points and 11.7 ± 3.8 points, respectively (p = 0.003). The recovery rate at the final follow-up was 22.6% in the fusion group and 43.4% in the non-fusion group, which were statistically comparable (p = 0.23). We observed no remarkable correlations between cervical sagittal spinal alignment parameters and JOA score recovery rate in the cohort, nor was any significant subluxation progression seen.

Conclusion

Compared with fusion surgery, surgical decompression alone may be a suitable and less invasive option for the treatment of non-inflammatory retro-odontoid pseudotumor with AAS, especially in elderly patients.

Long-Term Surgical Results of Skip Pedicle Screw Fixation for Patients with Adolescent Idiopathic Scoliosis: A Minimum-Ten-Year Follow-Up Study

Skip pedicle screw fixation for adolescent idiopathic scoliosis (AIS) requires fewer screws and can reduce the risk of neurovascular injury as compared with segmental pedicle screw fixation. However, the long-term impact of screw number reduction on correction and clinical results is unclear. This study examined the 10-year post-operative outcomes of skip pedicle screw fixation for patients with AIS. We reviewed the outcomes of 30 patients who underwent skip pedicle screw fixation for AIS. Radiological and clinical findings were assessed before and immediately, 2 years, and 10 years after surgery in the remaining 25 patients. The mean Cobb angle of the main curve preoperatively and immediately, 2 years, and 10 years post-operatively was 59.4°, 23.4°, 25.8°, and 25.60°, respectively, and was significantly improved at all post-surgical time points (all p < 0.001). The mean correction rate immediately after surgery was 60.8%, and the correction loss rate at the observation end point was 4.8%. The Cobb angle of the lumbar curve was significantly improved immediately after surgery, and the correction persisted until 10 years post-operatively. Remarkable gains were observed for most Scoliosis Research Society-22 patient questionnaire sub-scores at the final follow-up versus preoperative assessments. In conclusion, good correction of the AIS deformity by skip pedicle screw fixation was well maintained over a long follow-up period of 10 years, with clinically meaningful gains in Society-22 patient questionnaire sub-scores.

Scoliosis in Goldenhar syndrome with curve reversal during brace treatment: a case report

Background

Goldenhar syndrome sometimes displays progressive scoliosis and other spinal deformities that require treatment. However, few reports exist on scoliosis correction in Goldenhar syndrome. We described the rare radiological outcomes of a patient with Goldenhar syndrome who received brace treatment for scoliosis.

Case presentation

A 4-year-old boy was diagnosed as having Goldenhar syndrome and referred to our hospital for scoliosis treatment. The deformity deteriorated gradually, and left convex scoliotic angle was 26 degrees (T3-L2) at 11 years of age. Unexpectedly during treatment with an orthopedic brace, the curve had reversed to 21 degrees (T5-L2) at 7 months of therapy. After another adjustment of the brace, his right convex scoliotic angle improved to 13 degrees (T4-L2) at 15 months of treatment.

Conclusions

Curve reversal may occur during brace treatment for scoliosis in Goldenhar syndrome. Clinicians may opt to periodically check curve correction despite the risk of increased radiation exposure.

Posterior Spinal Fusion for Severe Spinal Deformities in Musculocontractural Ehlers-Danlos Syndrome: Detailed Observation of a Novel Case and Review of 2 Reported Cases

BACKGROUND

Musculocontractural Ehlers-Danlos syndrome caused by pathogenic variants in CHST14 (mcEDS-CHST14) is a recently delineated connective tissue disorder characterized by multisystem congenital malformations and progressive connective tissue fragility-related manifestations. With only 2 cases of mcEDS-CHST14 containing precise information on surgical spinal correction being reported to date, there remains no consensus on treatment standards. This study describes the detailed clinical and radiologic outcomes of the third known patient with mcEDS-CHST14 who successfully underwent surgery for severe kyphoscoliosis.

CASE DESCRIPTION

The patient was a 19-year-old girl with mcEDS-CHST14 who suffered from low back pain and decreased daily activities caused by progressive kyphoscoliosis. She underwent posterior spinal fusion with an all-pedicle screw construct from T4 to L4 for a preoperative main curve Cobb angle of 69 degrees and kyphotic angle of 27 degrees. Postoperative Cobb angle of the main curve and kyphotic angle were 26 and 6 degrees, respectively. Although sufficient correction was achieved without disseminated intravascular coagulation or other serious sequelae, a large amount of blood (2600 g) was lost due to tissue fragility. Her low back pain was decreased at 1 year after surgery.

CONCLUSIONS

On the basis of the present and 2 earlier reported cases, posterior spinal fusion may be a reasonable surgical option for severe progressive spinal deformities in patients with mcEDS-CHST14. However, careful attention is needed for possible massive blood loss from tissue fragility.

Residual thoracolumbar/lumbar curve is related to self-image after posterior spinal fusion for Lenke 1 and 2 curves in adolescent idiopathic scoliosis patients

OBJECTIVE

Although it is well known that major curve severity in adolescent idiopathic scoliosis (AIS) is inversely related to self-image, surgeons often encounter patients who complain of low self-image with preoperatively mild curves or postoperatively well-corrected main curves, suggesting the presence of other factors. This study examined factors contributing to self-image in AIS.

METHODS

A total of 86 consecutive patients who underwent posterior spinal fusion for AIS Lenke 1 or 2 curves and were followed for a minimum of 2 years were included in this study of patient self-image based on data that included scores reported on the Scoliosis Research Society survey (SRS-22r). The authors evaluated sex, BMI, Risser grade, age, angle of trunk rotation, Cobb angle of the main thoracic (MT) curve, Cobb angle of the thoracolumbar/lumbar (TL/L) curve, apical vertebral translation (AVT), T5-12 kyphotic angle, and clavicular angle. Univariate and multivariate general linear models were employed to identify preoperative and 2-year postoperative factors that impact self-image.

RESULTS

Univariate analysis revealed no significant correlation between preoperative MT curve Cobb angle and SRS-22r self-image score (p = 0.51), although patients with a higher MT curve AVT had a significantly worse preoperative self-image (p < 0.01). Two years postoperatively, larger Cobb angle of the TL/L curve (p = 0.01) and higher Risser grade (p = 0.03) resulted in significantly lower self-image scores. In multivariate testing, preoperative MT curve AVT remained significantly related to diminished self-image (p < 0.01). Two years later, higher TL/L curve (p < 0.01), Risser grade (p = 0.03), and MT curve AVT (p = 0.03) had significant associations with lower self-image scores.

CONCLUSIONS

Preoperative MT curve AVT appears more strongly related to self-image than does Cobb angle. Two years postoperatively, persistent TL/L region curvature and high Risser grade may also be associated with diminished patient self-image.

Upper instrumented vertebra to the right of the lowest instrumented vertebra as a predictor of an increase in the main thoracic curve after selective posterior fusion for the thoracolumbar/lumbar curve in Lenke type 5C adolescent idiopathic scoliosis: multicenter study on the relationship between fusion area and surgical outcome

OBJECTIVE

Unfused main thoracic (MT) curvatures occasionally increase after selective thoracolumbar/lumbar (TL/L) fusion. This study sought to identify the predictors of an unacceptable increase in MT curve (UIMT) after selective posterior fusion (SPF) of the TL/L curve in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS).

METHODS

Forty-eight consecutive patients (44 females and 4 males, mean age 15.7 ± 2.5 years, range 13-24 years) with Lenke type 5C AIS who underwent SPF of the TL/L curve were analyzed. The novel "Shinshu line" (S-line) was defined as a line connecting the centers of the concave-side pedicles of the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) on preoperative radiographs. The authors established an S-line tilt to the right as S-line positive (S-line+, i.e., the UIV being to the right of the LIV) and compared S-line+ and S-line- groups for thoracic apical vertebral translation (T-AVT) and MT Cobb angle preoperatively, early postoperatively, and at final follow-up. The predictors for T-AVT > 20 mm at final follow-up were evaluated as well. T-AVT > 20 mm was defined as a UIMT.

RESULTS

Among the 48 consecutively treated patients, 26 were S-line+ and 22 were S-line-. At preoperative, early postoperative, and final follow-up a minimum of 2 years later, the mean T-AVT was 12.8 mm (range -9.3 to 32.8 mm), 19.6 mm (range -13.0 to 41.0 mm), and 22.8 mm (range -1.9 to 68.7 mm) in the S-line+ group, and 10.8 mm (range -5.1 to 27.3 mm), 16.2 mm (range -11.7 to 42.1 mm), and 11.0 mm (range -6.3 to 26.9 mm) in the S-line- group, respectively. T-AVT in S-line+ patients was significantly larger than that in S-line- patients at the final follow-up. Multivariate analysis revealed S-line+ (odds ratio [OR] 23.8, p = 0.003) and preoperative MT Cobb angle (OR 7.9, p = 0.001) to be predictors of a UIMT.

CONCLUSIONS

S-line+ was defined as the UIV being to the right of the LIV. T-AVT in the S-line+ group was significantly larger than in the S-line- group at the final follow-up. S-line+ status and larger preoperative MT Cobb angle were independent predictors of a UIMT after SPF for the TL/L curve in patients with Lenke type 5C AIS. Surgeons should consider changing the UIV and/or LIV in patients exhibiting S-line+ during preoperative planning to avoid a possible increase in MT curve and revision surgery.

Ten-Year Results of Reconstruction for Rheumatoid Cervical Spine Lesions and Occurrence Factor of Subaxial Subluxation

Study Design

Retrospective chart review.

Purpose

This study evaluated long-term surgical outcomes of computer-assisted reconstruction using transarticular or cervical pedicle screws for cervical spine lesions caused by advanced rheumatoid arthritis (RA).

Overview of Literature

We routinely employ C1-C2 transarticular and cervical pedicle screw instrumentation to reconstruct advanced and unstable RA cervical lesions. However, few reports are available on the long-term results of surgical reconstruction for rheumatoid cervical disorders, particularly regarding cervical pedicle screw fixation.

Methods

Six subjects (all female) with RA cervical lesions who underwent atlantoaxial or occipitocervical fixation and were followed for at least 10 years were retrospectively studied. A frameless, stereotactic, optoelectronic, computed tomography-based image guidance system was used for correct screw placement. Variables including the Japanese Orthopaedic Association score, EuroQol, Ranawat value, and C2-C7 angle before and 2, 5, and 10 years after surgery were assessed along with the occurrence of subaxial subluxation (SAS).

Results

Mean age at initial surgery was 58.2±7 years (range, 51-68 years), and mean follow-up period was 141±11 months (range, 122-153 months). Lesions included atlantoaxial subluxation (AAS, n=2) and AAS+vertical subluxation (n=4). Mean C2-C7 lordotic angle before and 2, 5, and 10 years after surgery was 20.1°±6.1°, 21.0°±4.0°, 18.8°±4.7°, and 17.8°±5.3°, respectively. SAS did not occur in cases maintaining the C2-C7 lordotic angle. In two cases where the C2-C7 lordotic angle declined from 5 years postoperatively, SAS occurred at the C2-C3 level in one and at the C4-C5 level in the other, both of which required reoperation.

Conclusions

Patients with rheumatoid cervical lesions who undergo atlantoaxial or occipitocervical fixation using C1-C2 transarticular or pedicle screws carry a risk of SAS for up to 10 years postoperatively, which may require reoperation.