Effect of saline irrigation temperature difference on postoperative acute pain and hypothermia during biportal endoscopic spine surgery.

BACKGROUND: Recently, enhanced recovery after surgery (ERAS) protocols have attracted attention; they emphasize on avoiding intraoperative hypothermia while performing lumbar fusion surgery. However, none of the studies have reported the protocol for determining the temperature of saline irrigation during biportal endoscopic spine surgery (BESS) procedure. This study evaluated the effectiveness of warm saline irrigation during BESS in acute postoperative pain and inflammatory reactions. MATERIALS AND METHODS: Fifty-five patients who underwent BESS procedure were retrospectively analyzed for the incidence of perioperative hypothermia (< 36oC), postoperative inflammatory factors (white blood cells (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA)), and clinical outcomes (back visual analog scale (VAS) score, postoperative shivering). The patients were divided into the warm and cold saline irrigation groups. RESULTS: Hemoglobin, WBC, ESR, creatine kinase, and creatine kinase-muscle brain levels did not significantly differ between the warm and cold saline groups. The mean CRP, IL-6, and SAA levels were significantly higher in the cold saline group than in the warm saline group (p = 0.0058, 0.0028, and 0.0246, respectively); back VAS scores were also higher with a statistically significant difference until two days postoperatively (p < 0.001). During the entire procedure, the body temperature was significantly lower in the cold saline irrigation group, but the hypothermia incidence rate significantly differed 30 min after the operation was started. CONCLUSIONS: Using warm saline irrigation during BESS is beneficial for early recovery after surgery, as it is associated with reduced postoperative pain and complication rates.

Proximity Between Screw and Endplate of Upper Instrumented Vertebra Using a Cortical Bone Trajectory Screw can Increase Radiographic Adjacent Segment Degeneration Risks in Patients With Lumbar Spinal Stenosis.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: To determine the proximity between screw and endplate of the upper instrumented vertebra (UIV) using a cortical bone trajectory (CBT) screw as a predictive factor for radiographic adjacent segment degeneration (ASD) in patients surgically treated with transforaminal lumbar interbody fusion (TLIF) with CBT screws (CBT-TLIF) with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: The risk factors for radiographic ASD after CBT-TLIF remain unknown. METHODS: Among patients surgically treated with CBT-TLIF at a single institute, 239 consecutive patients (80 males and 159 females) were enrolled. ASD was defined by the presence of one or more of the following three radiologic criteria on the adjacent segment: >3 mm anteroposterior translation, >10° segmental kyphosis, or >50% loss of disc height comparing immediate postoperative and 1-year follow-up radiographs. Clinical and radiological features associated with the development of ASD were retrospectively measured. Univariate and multivariate analyses were performed to identify risk factors associated with radiographic ASD. RESULTS: Radiographic ASD was observed in 71 (29.7%) cases at 1-year postoperative follow-up. The preoperative Pfirrmann grade of the adjacent segment (>grade 2), multi-level fusion (>2 levels), and proximity between the tip of CBT screws and endplate on the UIV were significantly associated with radiographic ASD (OR = 3.98, 95% CI [1.06-15.05], P=0.042 versus OR = 3.03, 95% CI [1.00-9.14], P=0.049 versus OR = 0.53, 95% CI [0.40-0.72], P<0.001). The cut-off value of the distance between the tip of the screw and endplate on UIV for radiographic ASD was approximately 2.5 mm (right-sided CBT screw; cut-off value 2.48 mm/ left-sided CBT screw; cut-off value 2.465 mm). CONCLUSION: Radiographic adjacent segment degeneration progression can occur when the cortical trajectory bone screw is close to the endplate of the upper instrumented vertebrae in patients with lumbar spinal stenosis undergoing fusion surgery.

Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes.

Background: Laminoplasty is a common and effective surgery for decompression of the spinal cord in multilevel cervical myelopathy. The midline splitting technique (MST) and the unilateral open door technique (UODT) are the two most commonly performed laminoplasty techniques with continuous debate on which is preferable. This study aimed to add light to the matter by comparing and exploring the possible causes of different outcomes. Methods: A total of 101 patients who underwent laminoplasty for degenerative cervical myelopathy were included in this study. Radiographic measurements including C2-7 Cobb angle, C2-7 range of motion (ROM), Pavlov ratio of the most compressed level, and canal area with diameter were compared. Modified Japanese Orthopedic Association (mJOA) score and complications including C5 palsy, axial neck pain, hinge fractures, and spacer displacement were also compared. Statistical analysis was performed using independent samples t-test, chi-square test, Fisher's exact test, and linear mixed model. Results: C2-7 ROM, canal diameter, Pavlov ratio, and mJOA score did not demonstrate differences between the two techniques. The UODT group had greater postoperative canal expansion but had more loss of C2-7 lordosis than did the MST group. Of the complications, hinge fractures were more common in the UODT group, with more loss of C2-7 lordosis in patients with hinge fractures. On the other hand, spacer displacement occurred only in the MST group, with lesser canal expansion in patients with spacer displacement. Conclusions: The two laminoplasty techniques both demonstrated effectiveness in treating patients with multilevel cervical myelopathy. However, care should be given to avoid hinge fractures and spacer displacement since both can possibly lead to unfavorable outcomes.

Clinical significance of the C2 slope after multilevel cervical spine fusion.

OBJECTIVE: The C2 slope (C2S) is one of the parameters that can determine cervical sagittal alignment, but its clinical significance is relatively unexplored. This study aimed to evaluate the clinical significance of the C2S after multilevel cervical spine fusion. METHODS: A total of 111 patients who underwent multilevel cervical spine fusion were included in this study. The C2S, cervical sagittal vertical axis (cSVA), C2-7 lordosis, and T1 slope (T1S) were measured in standing lateral cervical spine radiographs preoperatively and 2 years after the surgery. Clinical outcome measures were visual analog scale (VAS) neck and arm pain scores, Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) scale score, and patient-reported subjective improvement rate (IR) percentage. Statistical analysis was performed using a paired-samples t-test and Pearson's correlation, and a receiver operating characteristic (ROC) curve to determine the cutoff values of C2S. RESULTS: C2S demonstrated a significant correlation with the cSVA, C2-7 lordosis, T1S, and T1S minus cervical lordosis. C2S revealed a significant correlation with the JOA, neck pain VAS, and NDI scores at 2 years after surgery. Change in the C2S correlated with postoperative neck pain and NDI scores. ROC curves demonstrated the cutoff values of C2S as 18.8°, 22.25°, and 25.35°, according to a cSVA of 40 mm, severe disability expressed by NDI, and severe myelopathy, respectively. CONCLUSIONS: C2S can be an additional cervical sagittal alignment parameter that can be a useful prognostic factor after multilevel cervical spine fusion.

Analysis of the Incidence and Risk Factors of Postoperative Delirium in Patients With Degenerative Cervical Myelopathy.

OBJECTIVE: The purpose of this study is to analyze various risk factors that can cause postoperative delirium (POD) in degenerative cervical myelopathy (DCM) patients, which may affect normal recovery and outcomes after surgery, and to help deal with them in advance and to take a medical approach. METHODS: A total of 148 patients aged 60 years or older who underwent laminoplasty or anterior cervical discectomy and fusion (ACDF) for DCM from 2008 to 2015 were included in this study. Incidence and multiple risk factors for development of POD were analyzed. RESULTS: POD occurred in 24 patients (16.2%). Among the 148 patients, 78 received laminoplasty, of whom 19 patients (24%) experienced delirium; the other 70 patients underwent ACDF, of whom 5 patients (7.1%) experienced delirium. History of Parkinson disease (odds ratio [OR], 178.242; p = 0.015), potassium level (OR, 3.764; p = 0.031), and surgical approach of laminoplasty over ACDF (OR, 8.538; p = 0.008) were found to be significant risk factors in a multivariate analysis. Age (OR, 1.056; p = 0.04) and potassium level (OR, 3.217; p = 0.04) were significant risk factors in the laminoplasty group. CONCLUSION: The findings of this study suggest that the incidence and risk factors for POD may vary in patients with DCM. It is necessary to understand multiple factors that affect the development of POD.

Cervical foraminal stenosis as a risk factor for cervical kyphosis following cervical laminoplasty.

BACKGROUND CONTEXT: Cervical laminoplasty (CLP) is an effective spinal cord decompression method for patients with cervical myelopathy. However, cervical kyphosis after CLP may cause insufficient decompression of the spinal cord. Thus, prevention of cervical kyphosis after CLP and identification of its risk factors are essential. PURPOSE: This study aimed to investigate the relationship between preoperative cervical foraminal stenosis and kyphotic changes after CLP. STUDY DESIGN: A retrospective study. PATIENT SAMPLE: We reviewed 108 patients who underwent CLP for cervical myelopathy between May 2014 and May 2019 and who were followed up for at least 24 months. OUTCOME MEASURES: For clinical assessments, neck pain, arm pain, neck disability index, Japanese Orthopedic Association scores, EuroQol 5-Dimension, and subjective improvement rate reported by the patients were evaluated. For radiologic parameters, C2-7 Cobb lordotic angle (CLA), C2-7 sagittal vertical axis, T1 slope (TS), TS minus CLA (TS-CLA), and cervical range of motion were assessed preoperatively and postoperatively for 24 months. Cervical foraminal stenosis was evaluated by magnetic resonance imaging and computed tomography. METHODS: The study population was divided into the kyphosis group (n = 25 patients) and the lordosis group (n = 83 patients) according to the CLA at 24 months postoperatively. Preoperative risk factors related to postoperative kyphosis were analyzed. Statistical analyses were performed using independent two-sample t test, Chi-square test, logistic regression analysis, and linear mixed model. RESULTS: Preoperative foraminal stenosis, CLA, TS, and TS-CLA were significantly different between the kyphosis and lordosis groups. In multivariate logistic regression analysis, foraminal stenosis (odds ratio [OR], 4.471; p = .0242) significantly increased the risk of kyphosis. The probability of developing kyphosis decreased with an increase in the CLA (OR, 0.840; p = .0001), while the probability of developing kyphosis increased with an increase in the TS-CLA (OR, 1.104; p = .0044). CONCLUSIONS: Preoperative cervical foraminal stenosis is an independent risk factor for cervical kyphosis following CLP. Thus, CLP may not be a suitable surgical option for cervical myelopathy combined with foraminal stenosis.

Effect of Medial Open-Wedge High Tibial Osteotomy on the Patellofemoral Joint According to Postoperative Realignment.

BACKGROUND: No study has yet assessed the effect of medial open-wedge high tibial osteotomy (MOWHTO) on the patellofemoral joint according to postoperative alignment. PURPOSE: To evaluate the effect of MOWHTO on the patellofemoral joint according to postoperative alignment by comparing the cartilage status before and after surgery and assessing the clinical and radiological outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 135 patients who underwent MOWHTO were retrospectively investigated. The patients were divided into 3 groups according to the postoperative weightbearing line ratio (WBLR): undercorrection (WBLR <58.3%, lowest quartile), acceptable correction (WBLR of 58.3%-66.3%, middle 2 quartiles), and overcorrection (WBLR >66.3%, highest quartile). The postoperative change in the cartilage status was assessed arthroscopically during implant removal at 2 years after MOWHTO. The clinical and radiological outcomes were evaluated at a mean follow-up of 52.1 months. A regression analysis was performed to identify the factors affecting the deterioration of the patellofemoral joint cartilage status. A receiver operating characteristic curve was employed to identify the cutoff point for the postoperative WBLR associated with the deterioration of the cartilage status in the patellofemoral joint. RESULTS: Of all patients, progression of cartilage degeneration was noted in 39.3% for femoral trochlea and 23.7% for patella. The incidence of cartilage progression was significantly higher in the overcorrection group than in the undercorrection and acceptable correction groups (femoral trochlea: undercorrection group = 30.3%, acceptable correction group = 32.4%, and overcorrection group = 61.8% [P = .008]; patella: undercorrection group = 15.2%, acceptable correction group = 17.7%, and overcorrection group = 44.1% [P = .005]). The functional outcomes, including Lysholm knee score, Knee injury and Osteoarthritis Outcome Score (Pain, Symptoms, and Activities of Daily Living subscales), and Shelbourne and Trumper score, were significantly worse in the overcorrection group. The regression analysis showed that only the postoperative WBLR had a significant effect on cartilage deterioration. The cutoff point for the postoperative WBLR associated with progression of the International Cartilage Repair Society grade was 62.1% for the femoral trochlea (sensitivity = 61.5%, specificity = 62.7%, accuracy = 66.2%) and 62.2% for the patella (sensitivity = 59.4%, specificity = 60.2%, accuracy = 67.8%). CONCLUSION: The patellofemoral joint was adversely affected by MOWHTO. Overcorrection causing excessive valgus alignment led to further progression of degenerative changes in the patellofemoral joint and inferior clinical outcomes. The postoperative WBLR can be used as a predictive factor for deterioration of the cartilage status in the patellofemoral joint after MOWHTO.