Does the presence of preoperative neck pain impact clinical outcomes after posterior decompression in patients with cervical ossification of the posterior longitudinal ligament?: Retrospective multicenter cohort study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To evaluate how preoperative neck pain influences clinical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL). SETTING: Fourteen medical institutions in Japan. METHODS: We enrolled 90 patients with cervical OPLL who underwent posterior decompression and were followed for a minimum of two years. We collected demographic data, medical history, and imaging findings. Patients were divided into two groups based on preoperative neck pain presence (Pre-op. neck pain (-) and (+) groups), and their outcomes were compared. RESULTS: There were no significant differences in patient demographics between the Pre-op. neck pain (-) and (+) groups. Both groups showed similar distributions of ossification types and K-line positivity. Perioperative complications were comparable between the two groups. Radiographic analysis revealed no significant differences in C2-7 angles or cervical range of motion, pre- and postoperatively. Both groups demonstrated significant improvement in postoperative Japanese orthopedic association (JOA) scores, but there were no significant differences in scores or recovery rates. In the Pre-op. neck pain (-) group, factors associated with appearance of postoperative neck pain included pre- and postoperative lower JOA scores and larger C2-7 angles in neutral and extension positions. CONCLUSIONS: It emerges that lower pre- and postoperative JOA scores or larger C2-7 angles in neutral and extension positions predispose to postoperative neck pain even in those patients without preoperative neck pain. Therefore, this is worth discussing at the time of consenting patients for surgical decompression and fixation.

Modified Intravascular Stent for Microvascular Suture in a Rat Superficial Femoral Artery.

BACKGROUND: Intravascular stent (IVaS) is sometimes used for suturing small vessels, but removing the stent after suturing is difficult. To overcome this problem, we developed an IVaS that integrates a stent and a manipulating string. This study aimed to investigate the usefulness of the modified IVaS (M-IVaS) by comparing it with conventional sutures (CS) and conventional IVaS (C-IVaS). METHODS: Forty-five superficial femoral arteries from rats were resected and sutured. The rats were randomly divided into the following 3 groups: CS, M-IVaS, and C-IVaS, with 15 rats per group. Patency rate, operating time, and ultrasonographic blood flow dynamics were examined immediately after suturing. Patency tests, ultrasonographic evaluations, and histological investigations were performed 1 week (n = 5), 2 weeks (n = 5), and 6 weeks (n = 5) after surgery. RESULTS: The 3 groups showed vessel patency in all cases immediately after suturing and at 1 week, 2 weeks, and 6 weeks after surgery. The mean operative time was 22.6 minutes for the CS group, 21.5 minutes for the M-IVaS group, and 25.9 minutes for the C-IVaS group. There were no significant differences in peak flow velocity and stenosis rate among the 3 groups as evaluated by ultrasonography. Histopathological evaluation revealed a similar recovery process of endothelial cells and no damage to the vascular wall. CONCLUSION: The surgical time using M-IVaS was significantly shorter compared to that using C-IVaS. The M-IVaS reduced the inconvenience of C-IVaS removal. M-IVaS showed the same effectiveness as did the CS in terms of patency rate, operating time, ultrasonographic blood flow dynamics, and histological evaluation. M-IVaS can be used in the field of microsurgery.

Natural history and surgical outcomes of idiopathic spinal cord herniation.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: Although surgery is frequently selected for the treatment of idiopathic spinal cord herniation (ISCH), its impact on functional outcomes has yet to be fully understood given the limited number of patients in previous studies. This study aims to evaluate the symptomatic history and surgical outcomes of ISCH. SETTING: Three institutions in Japan. METHODS: A total of 34 subjects with ISCH were retrospectively enrolled and followed up for at least 2 years. Demographic information, imaging findings, and clinical outcomes were collected. Functional status was assessed using the JOA score. RESULTS: The types of neurologic deficit were monoparesis, Brown-Sequard, and paraparesis in 5, 17, and 12 cases, with their mean disease duration being 1.2, 4.2, and 5.8 years, respectively. Significant differences in disease duration were observed between the monoparesis and Brown-Sequard groups (p < 0.01) and between the monoparesis and paraparesis groups (p = 0.04). Surgery promoted significantly better recovery rates from baseline. Correlations were observed between age at surgery and recovery rate (p < 0.01) and between disease duration and recovery rate (p = 0.04). The mean recovery rates were 82.6%, 51.6%, and 29.1% in the monoparesis, Brown-Sequard, and paraparesis groups, respectively. The monoparesis group had a significantly higher recovery rate than did the Brown-Sequard (p = 0.045) and paraparesis groups (p < 0.01). CONCLUSIONS: Longer disease duration was correlated with the progression of neurologic deficit. Older age, and worse preoperative neurologic status hindered postoperative functional recovery. These results highlight the need to consider surgical timing before neurologic symptoms deteriorate.

Hidden blood loss in extreme lateral interbody fusion for adult spinal deformity.

BACKGROUND: Extreme lateral interbody fusion (XLIF) is often used with posterior spinal fixation (PSF) to treat adult spinal deformity (ASD). However, the amount of intraoperative blood loss (IBL) reported for XLIF may underestimate the total blood loss (TBL). The objective of this study was to determine the total perioperative blood loss in XLIF for ASD. METHODS: We assessed 30 consecutive ASD patients with Schwab-SRS type L (mean age: 68.7 ± 8.2 years; mean follow-up 2.0 ± 1.3 years) who were treated by multilevel XLIF (mean, 2.5 ± 0.6 levels) followed by PSF after 3-5 days. We calculated the TBL after XLIF by the Gross equation, by hemoglobin (Hb) balance, and by the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula. We defined hidden blood loss (HBL) as the difference between the TBL and IBL. Pearson correlation, Spearman correlation, and multiple logistic regression analysis were performed to investigate the risk factors related to HBL. RESULTS: Post-XLIF blood tests showed a significant decrease in the Hb (from 11.8 ± 1.1 mg/dl to 10.6 ± 1.1 mg/dl) and hematocrit (from 36.0 ± 3.2% to 32.5 ± 3.2%). Although the mean IBL was relatively small (33 ± 52 mL), we calculated the TBL as 291 ± 171 mL (Gross equation) and the HBL as 258 ± 168 mL by Gross equation, which was 8 times greater than the IBL on average. There was no difference in the results obtained using the three methods. Multiple logistic regression analysis indicated preoperative lumber lordosis was the risk factor of high HBL (Odds ratio = 1.085, 95%CI: 1.006-1.170, p = 0.035). CONCLUSIONS: The HBL in XLIF was 8 times greater than the IBL. During the perioperative course of correction and fusion surgery for ASD with XLIF, surgeons need to pay attention not to underestimate the TBL.

Persistent low bone mineral density in adolescent idiopathic scoliosis: A longitudinal study.

BACKGROUND: Since osteopenia has been reported to potentially associated with the progression of scoliosis, bone mineral density (BMD) might have some influences on adolescent idiopathic scoliosis (AIS). However, little is known about longitudinal BMD changes in AIS patients. This study aimed to investigate whether osteopenia in preoperative AIS patients persist at bone maturity, and to evaluate the association between BMD and AIS severity. METHODS: We reviewed 61 AIS patients who underwent surgery when they were Risser grade 4 or below and less than 20 years old (16.6 ± 1.9 years), were followed until they were at least 18 years old and had a Risser grade of 5, and followed at least 2 years after the surgery (mean follow-up 4.9 ± 1.7 years). We evaluated radiographical parameters and proximal femur BMD before surgery and at the final follow-up. A BMD of less than the mean minus 1SD was considered as low BMD. Based on preoperative BMD, 37 patients were assigned to normal BMD (N) group (1.02 ± 0.08 g/cm2) and 24 patients to low BMD (L) group (0.82 ± 0.06 g/cm2). RESULTS: All patients in the N-group had normal BMD at the final follow-up. In the L group, 15 patients (62.5%) had low BMD at the final follow-up (L-L group; preoperative 0.79 ± 0.05 g/cm2 and final follow-up 0.78 ± 0.05 g/cm2). The mean preoperative Cobb angle was significantly larger in the L-L group (67.8 ± 11.2°) than in those with normal BMD at the final follow-up (L-N group, 55.6 ± 11.8°) or the N-N group (50.8 ± 7.6°). Preoperative BMD was significantly negative correlated with the preoperative Cobb angle. The age at surgery and mean preoperative BMI were similar in the L-N and L-L groups. CONCLUSIONS: Of AIS patients with low preoperative BMD, 62.5% still had low BMD after reaching bone maturity, and low BMD was associated with the severity of scoliosis.

Risk factors of AIS C incomplete cervical spinal cord injury for poor prognosis-The significance of anorectal evaluation.

BACKGROUND: Although the prognosis of incomplete cervical spinal cord injury (SCI) diagnosed as American Spinal Injury Association Impairment Scale grade C (AIS C) is generally favorable, some patients remain non-ambulatory. The present study explored the clinical factors associated with the non-ambulatory state of AIS C patients. METHODS: This study was a single-center retrospective observational study. Seventy-three participants with AIS C on admission were enrolled and divided into two groups according to ambulatory ability after one year. Prognostic factors of SCI were compared in ambulatory (A-group) and non-ambulatory participants (NA-group). Univariable and multivariable logistic regression analyses were performed on demographic information, medical history, mechanism of injury, presence of fracture, ASIA motor scores (MS) of the extremities, neurological findings, including an anorectal examination on admission, and imaging findings. RESULTS: Forty-one patients were included in the A-group and 32 in the NA-group. Univariable analysis revealed that the following factors were related to poor outcomes (p < 0.05): older age, history of cerebrovascular disorder, impairment/absence of S4-5 sensory score, deep anal pressure (DAP) (-), voluntary anal contraction (VAC) (-), anorectal tone (-), anal wink reflex (-), and low MS of the upper and lower extremities. In the multivariable analysis using age, presence or absence of sacral abnormality, and history of cerebrovascular disorders (adjusted for these three factors), older age and presence of sacral abnormality on admission were independent risk factors for a non-ambulatory state at the 1-year follow-up. CONCLUSIONS: Incomplete AIS C SCI individuals with older age and/or impairment of anorectal examination could remain non-ambulatory at 1-year follow-up.

Clinical outcomes and a therapeutic indication of intramedullary spinal cord astrocytoma.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Although intramedullary astrocytoma is associated with a high mortality rate, the optimal treatment has not reached a consensus. This study aimed at evaluating neurologic function and overall survival rate (OSR) in the treatment of this tumor. SETTING: The single institution in Japan. METHODS: This study enrolled 67 subjects who underwent surgical treatment for intramedullary astrocytoma. Demographic, imaging, and surgical information were collected from each participant. Tumors were histologically categorized using the World Health Organization classification, and subjects were divided into low-grade (I and II; n = 40) and high-grade (III and IV; n = 27) groups. Neurologic status was evaluated using the modified McCormick scale (MMS). OSR was assessed using Kaplan-Meier methods. RESULTS: The OSR decreased when the pathological grade increased (p < 0.01). Regarding the therapeutic efficacy for low-grade astrocytomas, subjects who underwent gross total resection (GTR) showed a higher OSR than those who did not (p = 0.02). GTR prevented worsening of MMS score, while non-GTR increased the MMS score (p < 0.01). In the high-grade group, 19 and 10 underwent radiation therapy and chemotherapy, respectively. However, both treatments did not improve OSR. Cordotomy was performed for subjects whose lesional area was at the thoracic level, but the OSR did not significantly increase. CONCLUSIONS: The most beneficial therapeutic strategy for low-grade astrocytomas was GTR, whereas that for the high-grade tumors was unclear. Further studies with a larger sample size are warranted to validate the effective treatment for malignant astrocytomas.

Comparison of surgical outcomes of posterior surgeries between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To compare the surgical outcomes and complications of posterior decompression between individuals with cervical spondylotic myelopathy (CSM) and those with ossification of the posterior longitudinal ligament (OPLL). SETTING: Seventeen medical institutions in Japan. METHODS: This study included 814 individuals with CSM (n = 636) and OPLL (n = 178) who underwent posterior decompression. Propensity score matching of the baseline characteristics was performed to compare surgical outcomes and perioperative complications between the CSM and OPLL groups. RESULTS: Before propensity score matching, the OPLL group had higher percentage of male individuals, body mass index, and number of stenosis levels and longer duration of symptoms (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively). After matching, the baseline characteristics were comparable between the CSM (n = 98) and OPLL (n = 98) groups. The postoperative Japanese Orthopaedic Association (JOA) scores, preoperative-to-postoperative changes in the JOA scores, and JOA score recovery rates were not significantly different between the groups (P = 0.42, P = 0.47, and P = 0.09, respectively). The postoperative visual analog scale (VAS) score for neck pain and preoperative-to-postoperative changes in the VAS score for neck pain were not significantly different between the groups (P = 0.25 and P = 0.50, respectively). The incidence of perioperative complications was comparable between groups. CONCLUSION: Neurological improvement and complication rates after surgery were comparable between individuals with CSM and those with OPLL, suggesting similar effectiveness and safety of posterior decompression for both conditions.

K-line (-) in the neck-flexed position negatively affects surgical outcome of expansive open-door laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: The K-line in the neck-flexed position (FK-line) on radiography reflects dynamic factors and cervical alignment. Although the FK-line has been reported to affect the neurological recovery after muscle-preserving selective laminectomy for cervical spondylotic myelopathy (CSM), its influence on surgical outcomes after expansive open-door laminoplasty (ELAP) has not been investigated. METHODS: We reviewed the surgical outcomes in 81 patients with multilevel CSM who underwent C4-C6 ELAP combined with C3 and C7 partial laminectomy using a laminoplasty plate and were followed up for at least 2 years. We defined the K-line (-) as some portion of a bony spur or the vertebral body crossing the FK-line, whereas the FK-line (+) was defined as that never crossing the FK-line. Patients were divided into the FK-line (+) (n = 61) and FK-line (-) groups (n = 20), and the surgical outcomes were compared between the groups. A multivariate analysis was performed to identify the factors that influenced the neurological outcomes. RESULTS: The FK-line (-) group had a smaller C2-C7 angle, smaller C7 slope, greater postoperative increase in the C2-C7 sagittal vertical axis, greater kyphosis in cervical flexion and less lordosis in cervical extension, and higher incidence of postoperative residual spinal cord compression. The preoperative-to-postoperative changes in the Japanese Orthopedic Association (JOA) score and JOA score recovery rate (RR) were lower in the FK-line (-) group. The multiple linear regression analysis revealed that the K-line (-) (ß = -0.327, P = 0.011) and high signal intensity (SI) changes on T2-weighted imaging (WI) combined with the low SI changes on T1-WI in the spinal cord (ß = -0.320, P = 0.013) negatively affected the JOA score RR. CONCLUSIONS: The FK-line can be used for patients with CSM as a simple indicator of neurological outcomes after ELAP.

Predictive factors for irreversible motor paralysis following cervical spinal cord injury.

STUDY DESIGN: A retrospective observational study. OBJECTIVES: To elucidate predictive clinical factors associated with irreversible complete motor paralysis following traumatic cervical spinal cord injury (CSCI). SETTING: Hokkaido Spinal Cord Injury Center, Japan. METHODS: A consecutive series of 447 traumatic CSCI persons were eligible for this study. Individuals with complete motor paralysis at admission were selected and divided into two groups according to the motor functional outcomes at discharge. Initial findings in magnetic resonance imaging (MRI) and other clinical factors that could affect functional outcomes were compared between two groups of participants: those with and those without motor recovery below the level of injury at the time of discharge. RESULTS: Of the 73 consecutive participants with total motor paralysis at initial examination, 28 showed some recovery of motor function, whereas 45 remained complete motor paralysis at discharge, respectively. Multivariate logistic regression analysis showed that the presence of intramedullary hemorrhage manifested as a confined low intensity changes in diffuse high-intensity area and more than 50% of cord compression on MRI were significant predictors of irreversible complete motor paralysis (odds ratio [OR]: 8.4; 95% confidence interval [CI]: 1.2-58.2 and OR: 14.4; 95% CI: 2.5-82.8, respectively). CONCLUSION: The presence of intramedullary hemorrhage and/or severe cord compression on initial MRI were closely associated with irreversible paralysis in persons with motor complete paralysis following CSCI. Conversely, subjects with a negligible potential for recovery could be identified by referring to these negative findings.