Radiological Spinopelvic Parameters Can Be Risk Factors for Early Total Hip Replacement After Spine Fusion.

BACKGROUND: Interest in the correlation between the spinopelvic complex and its radiographic parameters in early total hip arthroplasty has been increasing. This study investigated whether radiological spinopelvic parameters are risk factors for early total hip replacement (THR) within 1 year of spinal fusion surgery. The primary research question focused on identifying specific spinopelvic changes that may lead to early THR. METHODS: We retrospectively analyzed patients who underwent lumbar spinal fusion between 2016 and 2021. The patients were divided into 2 groups: patients who underwent early THR (n = 35) and patients who did not (n = 213). Spinopelvic parameters, including pelvic incidence (PI), sacral slope (SS), pelvic tilt, lumbar lordosis, thoracolumbar kyphosis (TLK), sagittal vertical axis, and thoracic kyphosis (TK), were measured before and after surgery. The statistical analyses included inverse probability of treatment weighting, independent t tests, χ 2 tests, and logistic regression analyses. RESULTS: A total of 248 patients were included in the study. The pre- and postoperative TLK and TK angles were significantly smaller in the early THR group than in the late THR group. Increases in the PI and SS after surgery were significant risk factors. The use of interbody fusion techniques was associated with a higher rate of early THR. The difference in the PI minus lumbar lordosis before and after surgery was also significantly correlated with early THR. CONCLUSIONS: Abnormal spinopelvic parameters, especially reduced TLK and TK angles and increased PI and SS, are risk factors for early THR. CLINICAL RELEVANCE: Changes in spinopelvic parameters can lead to rapid hip joint destruction, which highlights the need for careful preoperative evaluation and postoperative monitoring of patients to prevent early THR.

Shoulder Traction as a Possible Risk Factor for C5 Palsy in Anterior Cervical Surgery: A Cadaveric Study.

Background and Objectives: Many risk factors for postoperative C5 palsy (PC5P) have been reported regarding a "cord shift" after a posterior approach. However, there are few reports about shoulder traction as a possible risk factor of anterior cervical surgery. Therefore, we assessed the stretched nerve roots when shoulder traction was applied on cadavers. Materials and Methods: Eight cadavers were employed in this study, available based on age and the presence of foramen stenosis. After dissecting the sternocleidomastoid muscle of the cadaver, the shoulder joint was pulled with a force of 2, 5, 8, 10, 15, and 20 kg. Then, the stretched length of the fifth nerve root was measured in the extra-foraminal zone. In addition, the same measurement was performed after cutting the carotid artery to accurately identify the nerve root's origin. After an additional dissection was performed so that the superior trunk of the brachial plexus could be seen, the stretched length of the fifth and sixth nerve roots was measured again. Results: Throughout the entire experiment, the fifth nerve root stretched out for an average of 1.94 mm at 8 kg and an average of 5.03 mm at a maximum force of 20 kg. In three experiments, the elongated lengths of the C5 nerve root at 8 kg and 20 kg were 1.69/4.38 mm, 2.13/5.00 mm, and 0.75/5.31 mm, respectively, and in the third experiment, the elongated length of the C6 nerve root was 1.88/5.44 mm. Conclusions: Although this was a cadaveric experiment, it suggests that shoulder traction could be the risk factors for PC5P after anterior cervical surgery. In addition, for patients with foraminal stenosis and central stenosis, the risk would be higher. Therefore, the surgeon should be aware of this, and the patient would need sufficient explanation.

Sacroiliac Joint Degeneration After Lumbar or Lumbosacral Fusion Surgery-A Comparative Study of the Number of Fused Segments and Sacral Fusion.

OBJECTIVE: In this study, we aimed to investigate whether multi-segment fusion or fusion-to-sacrum increases sacroiliac joint (SIJ) pathology compared with single-segment fusion or a non-fused sacrum. METHODS: This study included 116 patients who underwent lumbar or lumbosacral fusion and were followed up for 2 years. The patients were classified into single-segment fusion (n = 46) and multi-segment fusion (more than two levels, n = 70) groups and then reclassified into the non-fused sacrum (n = 68) and fusion-to-sacrum groups (n = 48). Preoperative and postoperative radiographs were used to evaluate radiographic parameters, and computed tomography (CT) was used to evaluate SIJ degeneration. Low back pain (LBP) was assessed using a visual analog scale (VAS, 0-10). Baseline and postoperative values were compared using a paired sample t-test. RESULTS: LBP VAS scores significantly differed at 6 months (single-segment fusion, 3.04±1.88; multi-segment fusion, 4.83±2.33; P < 0.001) and 2 years postoperatively (single-segment fusion, 3.3±2.2; multi-segment fusion, 4.78±2.59; P = 0.094). There was no significant difference in SIJ degeneration, as assessed by CT scan, between the 2 surgical groups: 14 (30%) and 19 (27%) patients in the single-segment and multi-segment (P = 0.701) fusion groups, respectively. The LBP VAS scale showed comparable differences at 1 (non-fused sacrum, 3±2.18; fusion-to-sacrum, 3.74±2.28; P = 0.090) and 2 years postoperatively (non-fused sacrum, 3.29±2.01; fusion-to-sacrum, 4.66±2.71; P = 0.095). CT scan revealed that 18 (26%) and 15 (31%) patients in the non-fused sacrum and fusion-to-sacrum groups, respectively, developed SIJ arthritis; however, there was no significant intergroup difference (P = 0.574). CONCLUSIONS: SIJ degeneration occurs independent of the number of fused segments or sacrum involvement.

Association of Untreated Pre-surgical Depression With Pain and Outcomes After Spinal Surgery.

STUDY DESIGN: Prospective Cohort Study. OBJECTIVE: Untreated pre-surgical depression may prolong post-surgical pain and hinder recovery. However, research on the impact of untreated pre-surgical depression on post-spinal surgery pain is lacking. Therefore, this study aimed to assess pre-surgical depression in patients and analyze its relationship with post-surgical pain and overall post-surgical outcomes. METHODS: We recruited 100 patients scheduled for lumbar spine surgery due to spondylolisthesis, degenerative lumbar disc diseases, and herniated lumbar disc diseases. Psychiatrists evaluated them for the final selection. We assessed the Beck Depression Inventory (BDI), Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), and EuroQoL 5 Dimensions (EQ-5D) scores, numerical back and leg pain scales, and medication dosage data collected before and at 6 weeks, 3 months, and 6 months after surgery. RESULTS: Ninety-one patients were included in this study; 40 and 51 were allocated to the control and depression groups, respectively. The pre- and post-surgical leg pain, back pain, and functional scores were not different. However, the depression group showed higher ODI and EQ-5D and lower JOA scores than the control group 3 months post-surgery. Partial correlation analysis revealed an inverse correlation between the JOA and BDI scores and a positive correlation between the EQ-5D and BDI scores at 3 months postoperatively. CONCLUSION: Untreated depression can prolong postoperative pain and hinder recovery. Detecting and treating depression in patients before spine surgery may improve their overall quality of life and functional recovery.

Accelerated fusion dynamics by recombinant human bone morphogenetic protein-2 following transforaminal lumbar interbody fusion, particularly in osteoporotic conditions.

BACKGROUND CONTEXT: Early fusion is crucial in interbody procedures to minimize mechanical complications resulting from delayed union, especially for patients with osteoporosis. Bone morphogenetic proteins (BMPs) are used in spinal fusion procedures; however, limited evaluation exists regarding time-to-fusion for BMP use, particularly in patients with osteoporosis. PURPOSE: To evaluate the difference in time-to-fusion after single-level transforaminal lumbar interbody fusion (TLIF) surgery between recombinant human bone morphogenetic protein-2 (rhBMP-2) usage and nonusage groups according to bone density. STUDY DESIGN: Retrospective single-center cohort study. PATIENT SAMPLE: This study enrolled 132 patients (mean age, 65.25±8.66; male patients, 40.9%) who underwent single-level TLIF for degenerative disorders between February 2012 and December 2021, with pre- and postoperative computed tomography (CT). OUTCOME MEASURE: The interbody fusion mass and bone graft status on postoperative CT scans was obtained annually, and time-to-fusion was recorded for each patient. METHODS: The patients were divided into 2 groups based on rhBMP-2 use during the interbody fusion procedure. Patients were further divided into osteoporosis, osteopenia, and normal groups based on preoperative L1 vertebral body attenuation values, using cutoffs of 90 and 120 Hounsfield units. It was strictly defined that fusion is considered complete when a trabecular bone bridge was formed, and therefore, the time-to-fusion was measured in years. Time-to-fusion was statistically compared between BMP group and non-BMP groups, followed by further comparison according to bone density. RESULTS: The time-to-fusion differed significantly between BMP and non-BMP groups, with half of the patients achieving fusion within 2.5 years in the BMP group compared with 4 years in the non-BMP group (p<.001). The fusion rate varied based on bone density, with the maximum difference observed in the osteoporosis group, when half of the patients achieved fusion within 3 years in the BMP group compared to 5 years in the non-BMP group (p<.001). Subgroup analysis was conducted, revealing no significant associations between time-to-fusion and factors known to influence the fusion process, including age, gender, medical history, smoking and alcohol use, and medication history, except for rh-BMP2 use and bone density. CONCLUSIONS: RhBMP-2 usage significantly reduced time-to-fusion in single-level TLIF, especially in patients with osteoporosis. LEVEL OF EVIDENCE: Level III.

Long-Term Incidence of Adjacent Segmental Pathology After Minimally Invasive vs. Open Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare the incidence of adjacent segmental pathology (ASP) following minimally invasive (MI) vs open transforaminal lumbar interbody fusion (TLIF) and to identify factors linked to ASP requiring reoperation. METHODS: This retrospective study reviewed the outcomes of patients who underwent MI-TLIF or open TLIF. Radiographic ASP (RASP) was evaluated using X-ray imaging to distinguish between degenerative changes, spondylolisthesis, and instability in the adjacent spinal segment. Clinical ASP (CASP) was assessed with the visual analog scale score for leg and back pain and the Oswestry disability index. Patient data were collected 1, 2, 5, and 10 years postoperatively. The timing and frequency of ASP reoperation were analyzed. RESULTS: Five years postoperatively, the RASP rate was 35.23% and 45.95% in the MI-TLIF and open TLIF groups. The frequency of CASP differed significantly between the MI-TLIF and open TLIF groups at 1 year postoperatively. The rates of RASP, CASP, and ASP necessitating reoperation were not significantly different 10 years postoperatively. Cranial facet violation significantly affected ASP in both groups. In the open TLIF group, preoperative adjacent segment disc degeneration significantly influenced ASP. CONCLUSION: The RASP rate at 5 years postoperatively and the CASP rate at 1 year postoperatively differed significantly between groups. There was no difference in the rate of ASP requiring reoperation. Cranial facet violation is a crucial driving factor for ASP after both surgical procedures.

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.

Risk Factors and Characteristics of In-Hospital Falls After Spine Surgery: A Retrospective, Single-Center Cohort Study in the Republic of Korea.

Background: Falls after orthopaedic surgery can cause serious injuries, which lengthen hospital stays and increase medical expenses. This has prompted hospitals to implement various fall-prevention protocols. The aims of this study were to determine the incidence of in-hospital falls after spine surgery, to analyze the overall risk factors, to discern factors that have a major influence on falls, and to evaluate the effectiveness of the fall-prevention protocol that we implemented. Methods: This was a retrospective, single-center study including patients who underwent spine surgery from January 2011 to November 2021 at the National Health Insurance Service Ilsan Hospital (NHISIH) in Goyang, Republic of Korea. Reported falls among these patients were examined. Patient demographics; surgery type, date, and diagnosis; and fall date and time were evaluated. Results: Overall, 5,317 spine surgeries were performed, and 128 in-hospital falls were reported (overall incidence: 2.31%). From the multivariable analyses, older age and American Society of Anesthesiologists (ASA) score were identified as independent risk factors for in-hospital patient falls (multivariable adjusted hazard ratio [aHR] for age 70 to 79 years, 1.021 [95% confidence interval (CI), 1.01 to 1.031]; for age ≥80 years, 1.035 [1.01 to 1.06]; and for ASA score of 3, 1.02 [1.01 to 1.031]). Similar results were seen in the subgroup who underwent primary surgery. Within 2 weeks following surgery, the highest frequency of falls occurred at 3 to 7 days postoperatively. The lowest fall rate was observed in the evening (6 to 10 p.m.). Morbidities, including rib, spine, and extremity fractures, were recorded for 14 patients, but none of these patients underwent operative treatment related to the fall. The NHISIH implemented a comprehensive nursing care service in May 2015 and a fall protocol in May 2017, but the annual incidence rate did not improve. The fall rate was higher after thoracolumbar surgeries (2.47%) than after cervical surgeries (1.20%). Moreover, a higher fall rate was observed in thoracolumbar cases with a greater number of fusion levels and revision spine surgeries. Conclusions: Patients with advanced age, more comorbidities, a greater number of fusion levels, and revision surgeries and who are female are more vulnerable to in-hospital falls after spine surgery. Novel strategies that target these risk factors are warranted. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Clinical and radiological outcomes of non-window-type bioactive glass-ceramic cage in single-level ACDF versus PEEK cage filled with autologous bone.

Bioactive glass-ceramic (BGC) cage is a substitute for polyether ether ketone (PEEK) cages in anterior cervical discectomy and fusion (ACDF). Only a few comparative studies exist using PEEK and non-window-type BGC cages (CaO-SiO2-P2O5-B2O3) in single-level ACDF. This study compared PEEK cages filled with autologous iliac bone grafts and BGC cages regarding clinical safety and effectiveness. A retrospective case series was performed on 40 patients who underwent single-level ACDF between October 2020 and July 2021 by a single orthopedic spine surgeon. The spacers used in each ACDF were a PEEK cage with a void filled with an autologous iliac bone graft and a non-window-type BGC cage in 20 cases. The grafts were compared pre-operatively and post-operatively at 6 weeks and 3, 6, and 12 months. Post-operative complications were investigated in each group. Clinical outcome was measured, including Visual Analog Scale (VAS) scores of neck and arm pains, Japanese Orthopedic Association score (JOA), and Neck Disability Index (NDI). Dynamic lateral radiographs were used to assess the inter-spinous motion (ISM) between the fusion segment and subsidence. The fusion status was evaluated using a computed tomography (CT) scan. Overall, 39 patients (19 and 20 patients in the PEEK and BGC groups, respectively) were recruited. Eighteen (94.7%) and 19 (95.0%) patients in the PEEK and BGC groups, respectively, were fused 12 months post-operatively, as assessed by ISM in dynamic lateral radiograph and bone bridging formation proven in CT scan. The PEEK and BGC groups showed substantial improvement in neck and arm VAS, JOA, and NDI scores. No substantial difference was found in clinical and radiological outcomes between the PEEK and BGC groups. However, the operation time was considerably shorter in the BGC group than in the PEEK group. In conclusion, a non-window-type BCG cage is a feasible substitute for a PEEK cage with an autologous iliac bone graft in single-level ACDF.

Association of Functional Gastrointestinal Disorders with Adolescent Idiopathic Scoliosis.

Numerous adolescents diagnosed with adolescent idiopathic scoliosis (AIS) often manifest symptoms indicative of functional gastrointestinal disorders (FGIDs). However, the precise connection between FGIDs and AIS remains unclear. The study involved adolescents drawn from sample datasets provided by the Korean Health Insurance Review and Assessment Service spanning from 2012 to 2016, with a median dataset size of 1,446,632 patients. The AIS group consisted of individuals aged 10 to 19 with diagnostic codes for AIS, while the control group consisted of those without AIS diagnostic codes. The median prevalence of FGIDs in adolescents with AIS from 2012 to 2016 was 24%. When accounting for confounding factors, the analysis revealed that adolescents with AIS were consistently more prone to experiencing FGIDs each year (2012: adjusted odds ratio (aOR), 1.21 [95% confidence interval (CI), 1.10-1.35], p < 0.001; 2013: aOR, 1.31 [95% CI, 1.18-1.46], p < 0.001; 2014: aOR, 1.24 [95% CI, 1.12-1.38], p < 0.001; 2015: aOR, 1.34 [95% CI, 1.21-1.49], p < 0.001; and 2016: aOR, 1.35 [95% CI, 1.21-1.50], p < 0.001). These findings suggest that AIS is correlated with an elevated likelihood of FGIDs, indicating that AIS may function as a potential risk factor for these gastrointestinal issues. Consequently, it is recommended to provide counseling to adolescents with AIS, alerting them to the heightened probability of experiencing chronic gastrointestinal symptoms.

Effectiveness of Toothbrushing Technique for Biofilm Removal and Postoperative Infection Control after Spinal Fusion Surgery: A Retrospective Study.

This retrospective study was designed to investigate the effectiveness of using a toothbrush, which is commonly used in our daily life, for biofilm removal and infection control in the treatment of spinal infections occurring after spinal fusion surgery. Currently, a biofilm is thought to form on the surface of the metal inserted during spine fusion surgery. We aim to determine the differences in clinical outcomes between using and not using a toothbrush to remove biofilm while performing conventional drainage, curettage, and debridement. A total of 1081 patients who underwent anterior or posterior spinal fusion surgery between November 2018 and October 2022 were screened. The study included 60 patients who developed surgical site infection and underwent incision and drainage surgery either with a toothbrush (n = 20) or without a toothbrush (n = 40). Failure of infection control that requires revision surgery occurred in 2 patients (10%) in the Toothbrush group and in 14 patients (35%) in the No-Toothbrush group (p = 0.039). Thus, the rate of additional surgery was significantly lower in the Toothbrush group. Additionally, normalization of c-reactive protein levels occurred significantly faster in the Toothbrush group (p = 0.044). Therefore, using a toothbrush to treat spinal infections following spinal fusion surgery appears to have beneficial mechanical debridement effects, resulting in improved clinical results, which were also confirmed based on the electron microscopic images.

Assessment of Biomechanical Advantages in Combined Anterior-Posterior Cervical Spine Surgery by Radiological Outcomes: Pedicle Screws over Lateral Mass Screws.

BACKGROUND: The combined anterior-posterior approach has shown good clinical outcomes for multilevel cervical diseases. This work describes the biomechanical advantage of cervical-pedicle-screw fixation over lateral-mass-screw fixation in combined anterior-posterior cases. METHOD: Seventy-six patients who received combined cervical surgery from June 2013 to December 2020 were included. The patients were divided into two groups: the lateral-mass-screw group (LMS) and the pedicle-screw group (PPS). Radiological outcomes were assessed with lateral cervical spine X-rays for evaluating sagittal alignment, subsidence, and bone remodeling. RESULTS: At 1 year postoperatively, the numbers of patients whose C2-C7 cervical lordosis was less than 20 degrees decreased by more in the PPS group (p-value = 0.001). The amount of vertical-length change from immediately to 1 year postsurgery was less in the PPS group than in the LMS group (p-value = 0.030). The mean vertebral-body-width change was larger in the PPS group than in the LMS group during 3 months to 1 year postsurgery (p-value = 0.000). CONCLUSIONS: In combined anterior-posterior cervical surgery cases, maintenance of cervical lordosis and protection of the vertebral body from subsidence were better with the pedicle-screw fixation. More bone remodeling occurred when using the pedicle-screw fixation method.

The Clinical Use of Osteobiologic and Metallic Biomaterials in Orthopedic Surgery: The Present and the Future.

As the area and range of surgical treatments in the orthopedic field have expanded, the development of biomaterials used for these treatments has also advanced. Biomaterials have osteobiologic properties, including osteogenicity, osteoconduction, and osteoinduction. Natural polymers, synthetic polymers, ceramics, and allograft-based substitutes can all be classified as biomaterials. Metallic implants are first-generation biomaterials that continue to be used and are constantly evolving. Metallic implants can be made from pure metals, such as cobalt, nickel, iron, or titanium, or from alloys, such as stainless steel, cobalt-based alloys, or titanium-based alloys. This review describes the fundamental characteristics of metals and biomaterials used in the orthopedic field and new developments in nanotechnology and 3D-printing technology. This overview discusses the biomaterials that clinicians commonly use. A complementary relationship between doctors and biomaterial scientists is likely to be necessary in the future.

Posterior Preventive Foraminotomy before Laminectomy Combined with Pedicle Screw Fixation May Decrease the Incidence of C5 Palsy in Complex Cervical Spine Surgery in Patients with Severe Myeloradiculopathy.

C5 palsy is a frequent sequela of cervical decompression surgeries for cervical myeloradiculopathy. Although many researchers have suggested various risk factors, such as cord shifting and the correction of lordotic angles, the tethering of the C5 root beneath the narrow foramen is an independent risk factor for C5 palsy. In this study, we tried to investigate different techniques for foramen decompression with posterior cervical fusion and assess the incidence of C5 palsy with each technique depending on the order of foraminal decompression. A combined 540° approach with LMS and uncovertebrectomy was used in group 1. Group 2 combined a 540° approach with pedicle screws and posterior foraminotomy, while posterior approach only with pedicle screws and foraminotomy was used in group 3. For groups 2 and 3, prophylactic posterior foraminotomy was performed before laminectomy. Motor manual testing to assess C5 palsy, the Neck Disability Index (NDI) and the Japanese Orthopedic Association (JOA) scores were determined before and after surgery. Simple radiographs, MRI and CT scans, were obtained to assess radiologic parameters preoperatively and postoperatively. A total of 362 patients were enrolled in this study: 208 in group 1, 72 in group 2, and 82 in group 3. The mean age was 63.2, 65.5, and 66.6 years in groups 1, 2, and 3, respectively. The median for fused levels was 4 for the three groups. There was no significant difference between groups regarding the number of fused levels. Weight, height, comorbidities, and diagnosis were not significantly different between groups. Preoperative JOA scores were similar between groups (p = 0.256), whereas the preoperative NDI score was significantly higher in group 3 than in group 2 (p = 0.040). Mean JOA score at 12-month follow-up was 15.5 ± 1.89, 16.1 ± 1.48, and 16.1 ± 1.48 for groups 1, 2, and 3, respectively; it was higher in group 3 compared with group 1 (p = 0.008) and in group 2 compared with group 1 (p = 0.024). NDI score at 12 months was 13, 12, and 13 in groups 1, 2, and 3, respectively; it was significantly better in group 3 than in group 1 (p = 0.040), but there were no other significant differences between groups. The incidence of C5 palsy was significantly lower in posterior foraminotomy groups with pedicle screws (groups 2 and 3) than in LMS with uncovertebrectomy (group 1) (p < 0.001). Thus, preventive expansive foraminotomy before decompressive laminectomy is able to significantly decrease the root tethering by stenotic lesion, and subsequently, decrease the incidence of C5 palsy associated with posterior only or combined posterior and anterior cervical fusion surgeries. Additionally, such expansive foraminotomy might be appropriate with pedicle screw insertion based on biomechanical considerations.

A Comparison Between Cortical Bone Trajectory Screws And Traditional Pedicle Screws in Patients With Single-Level Lumbar Degenerative Spondylolisthesis: Five-Year Results.

STUDY DESIGN: A retrospective observational study. OBJECTIVE: This study investigated the clinical and radiological results of using cortical bone trajectory (CBT) screws versus traditional pedicle (TP) screws in transforaminal lumbar interbody fusion (TLIF) during a five-year follow-up of patients with single-level lumbar degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Few studies have compared five-year follow-up outcomes between CBT screws and TP screws in TLIF. MATERIALS AND METHODS: We reviewed outcome data of patients with single-level lumbar degenerative spondylolisthesis who underwent TLIF procedures with CBT screws (131 patients) or TP screws (80 patients) between 2011 and 2015. Patient-reported clinical outcome data included Oswestry disability index scores and visual analog scale (VAS) scores for back and leg pain at baseline, six months, and one year, two years, and five years postoperatively. The radiographic fusion rate and prevalence of secondary surgery for adjacent segment disease were also measured. RESULTS: During the follow-up over five years, the CBT group had significantly lower VAS scores for back pain ( P <0.0001, respectively). At two years after surgery, the CBT group had significantly higher VAS scores for leg pain ( P =0.007). At five years postoperatively, no significant differences existed in the VAS score for leg pain or in the Oswestry disability index score between the two groups. Radiographic fusion rates (CBT vs. TP: 95.5% vs. 95.9%; P =0.881) and adverse events during the five years after surgery were not significantly different. At two years postoperatively, the prevalence of secondary surgery to treat adjacent segment disease was significantly different between the two groups (CBT vs . TP: 13.7% vs. 5.0%; P =0.044). CONCLUSIONS: Our results suggest that, during a five-year followup, CBT screws for TLIF were an effective treatment compared to TP screws in the setting of single-level lumbar degenerative spondylolisthesis. However, when using CBT screws for TLIF, surgeons should consider the higher rate of secondary procedures to treat symptomatic adjacent segment disease.

A Comparative Analysis of Bi-Portal Endoscopic Spine Surgery and Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Stenosis Patients.

The clinical and radiological results before and after surgery were compared and analyzed for patients with multilevel lumbar stenosis who underwent bi-portal endoscopic spine surgery (BESS) and microscopic unilateral laminotomy for bilateral decompression (ULBD). We retrospectively identified 47 and 49 patients who underwent BESS and microscopic ULBD, respectively, who were diagnosed with multi-level lumbar stenosis. Clinical outcomes were evaluated using the visual analog scale score for both back and leg pain, and medication (pregabalin) use and Oswestry Disability Index (ODI) scores for overall treatment outcomes were used pre-operatively and at the final follow-up. Radiological outcomes were evaluated as the percentage of dura expansion volume, and percentage preservation of both facets and both lateral recess angles. The follow-up period of patients was about 17.04 months in the BESS group and about 16.90 months in the microscopic ULBD group. The back and leg visual analog scale (VAS) scores and average pregabalin use decreased more significantly in the BESS group than in the microscopic ULBD group (each p-value 0.0443, <0.001, 0.0378). All radiological outcomes were significantly higher in the BESS group than in the ULBD group. The change in ODI in two-level spinal stenosis showed a significantly higher value in the BESS group compared to the microscopic ULBD group (p-value 0.0335). Multilevel decompression with the BESS technique in multiple spinal stenosis is an adequate technique as it shows better clinical and radiological results than microscopic ULBD during a short-term follow-up period.

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.

Anterior Plate-Screws and Lower Postoperative T1 Slope Affect Cervical Allospacer Failures in Multi-Level ACDF Surgery: Anterior Versus Posterior Fixation.

STUDY DESIGN: Prospective observational study. OBJECTIVE: In ACDF, graft failure and subsidence are common complications of surgery. Depending on the cervical fixation, different biomechanical characteristics are applied on the grafts. This aims to describe the incidence of cervical spacer failure in patients with cervical degenerative condition according to the cervical fixation method and sagittal balance. METHOD: From November 2011 to December 2015, 262 patients who underwent cervical spine surgery were enrolled prospectively. Patients were divided into 3 groups based on fixation method: anterior plate/screw (APS), posterior lateral mass screw (LMS), pedicle screw (PPS) groups. Serial X-rays and CT scans were utilized to evaluate radiologic outcomes. RESULTS: Mean patient ages were 56.1 years in the APS group, 61.5 years in the LMS group, and 57.6 years in the PPS group (P = 0.002). Allospacer failure was most common in the APS group, compared to the LMS and PPS groups (chi-square, P = 0.038). Longer fusion level was associated with greater allospacer failure (Baseline 2 level surgery; Odds ratio (OR) 3.4 in 3 level, 15.2 in 4 level, P = 0.036,0.013). Higher T1 slope was correlated with less allospacer failure (OR 0.875, P = 0.001). ORs of allospacer failure in the LMS and PPS groups were 0.04 and 0.02, respectively, (P = 0.01, 0.01), compared with the APS group. CONCLUSION: This study was able to show that allospacer failure in multi-level ACDF surgery is more common with a longer fusion length, less postoperative T1 slope, and an anterior plate-screws technique. Pedicle screws provided the best biomechanical stability among the 3 constructs.