Feasibility of the Non-Window-Type 3D-Printed Porous Titanium Cage in Posterior Lumbar Interbody Fusion: A Randomized Controlled Multicenter Trial.

BACKGROUND: Three-dimensionally printed titanium (3D-Ti) cages can be divided into 2 types: window-type cages, which have a void for bone graft, and non-window-type cages without a void. Few studies have investigated the necessity of a void for bone graft in fusion surgery. Therefore, the present study assessed the clinical and radiographic outcomes of window and non-window-type 3D-Ti cages in single-level posterior lumbar interbody fusion. METHODS: A total of 70 patients were randomly assigned to receive either a window or non-window cage; 61 patients (87%) completed final follow-up (32 from the window cage group, 29 from the non-window cage group). Radiographic outcomes, including fusion rates, subsidence, and intra-cage osseointegration patterns, were assessed. Intra-cage osseointegration was measured using the intra-cage bridging bone score for the window cage group and the surface osseointegration ratio score for the non-window cage group. Additionally, we looked for the presence of the trabecular bone remodeling (TBR) sign on computed tomography (CT) images. RESULTS: Of the 61 patients, 58 achieved interbody fusion, resulting in a 95.1% fusion rate. The fusion rate in the non-window cage group was comparable to, and not significantly different from, that in the window cage group (96.6% and 93.8%, p > 0.99). The subsidence rate showed no significant difference between the window and non-window cage groups (15.6% and 3.4%, respectively; p = 0.262). The intra-cage osseointegration scores showed a significant difference between the groups (p = 0.007), with the non-window cage group having a higher proportion of cases with a score of 4 compared with the window cage group. The TBR sign was observed in 87.9% of patients who achieved interbody fusion, with a higher rate in the non-window cage group across the entire cohort although the difference was not significant (89.7% versus 78.1%, p = 0.385). CONCLUSIONS: Non-window-type 3D-Ti cages showed equivalent clinical outcomes compared with window-type cages and comparable interbody fusion rates. These results suggest that the potential advantages of 3D-Ti cages could be optimized in the absence of a void for bone graft by providing a larger contact surface for osseointegration. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Reoperation Rates According to Surgical Approach After Operation for Degenerative Cervical Pathology in Patients With Athetoid Cerebral Palsy: A Nationwide Cohort Study.

STUDY DESIGN: National population-based cohort study. OBJECTIVE: The overall complication rate for patients with athetoid cerebral palsy (CP) undergoing cervical surgery is significantly higher than that of patients without CP. The study was conducted to compare the reoperation and complication rates of anterior fusion, posterior fusion, combined fusion, and laminoplasty for degenerative cervical myelopathy/radiculopathy in patients with athetoid cerebral palsy. METHODS: The Korean Health Insurance Review and Assessment Service national database was used for analysis. Data from patients diagnosed with athetoid CP who underwent cervical spine operations for degenerative causes between 2002 and 2020 were reviewed. Patients were categorized into four groups for comparison: anterior fusion, posterior fusion, combined fusion, and laminoplasty. RESULTS: A total of 672 patients were included in the study. The overall revision rate was 21.0% (141/672). The revision rate was highest in the anterior fusion group (42.7%). The revision rates of combined fusion (11.1%; hazard ratio [HR], .335; P = .002), posterior fusion (13.8%; HR, .533; P = .030) were significantly lower than that of anterior fusion. Revision rate of laminoplasty (13.1%; HR, .541; P = .240) was also lower than anterior fusion although the result did not demonstrate statistical significance. CONCLUSION: Anterior fusion presented the highest reoperation risk after cervical spine surgery reaching 42.7% in patients with athetoid CP. Therefore, anterior-only fusion in patients with athetoid CP should be avoided or reserved for strictly selected patients. Combined fusion, with the lowest revision risk at 11.1%, could be safely applied to patients with athetoid CP.

Feasibility of Non-window Three-Dimensional-Printed Porous Titanium Cage in Posterior Lumbar Interbody Fusion: A Pilot Trial.

Background: The commercially available design of a three-dimensional (3D)-printed titanium (3D-Ti) cage can be divided into two types according to the presence of a window: a cage with a window that allows filling of bone graft materials and a non-window cage for stand-alone use. This prospective observational case series study aimed to explore the clinical feasibility of using a non-window type 3D-Ti cage in cases of combined window and non-window cage implantation. Furthermore, we evaluated the bone in growth patterns of non-window cages and their correlation with published fusion grading systems. Methods: A total of 31 consecutive patients who underwent single-level posterior lumbar interbody fusion surgery were included. Two 3D-Ti cages with different designs were inserted: a non-window cage on the left side and a window cage on the right side. Radiographic fusion was defined by the segmental angle between flexion and extension radiographs (F-E angle) and cage bridging bone (CBB) scores on computed tomography. The association between the F-E angle and osteointegration scoring system including the surface osteointegration ratio (SOR) score was analyzed. Results: Radiographic fusion was achieved in 27 of 31 patients (87%) at 12 months postoperatively. Among the non-window cages, 23 of 31 (74.2%) had fair SOR scores, while 19 of 31 (61.3%) window cages had fair intra-cage CBB scores. The higher the SOR score was, the smaller the flexion-extension angle (SOR 0 vs. SOR 1: 6.30° ± 2.43° vs. 1.95° ± 0.99°, p < 0.001; SOR 0 vs. SOR 2: 6.03° ± 2.43° vs. 0.99°± 0.74°, p < 0.001). Conclusions: The clinical feasibility of using a non-window 3D-Ti cage during lumbar interbody fusion might be acceptable. Furthermore, a newly suggested fusion criterion for the use of the non-window cage, the SOR score, showed a significant association with the published fusion grading systems, demonstrating its feasibility in determining interbody fusion in lumbar spinal surgery.

Which Radiographic Parameter Can Aid in Deciding Optimal Allograft Height for Anterior Cervical Discectomy and Fusion?

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To identify preoperative radiographic parameters that can guide optimal allograft height selection for anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Allograft height selection for ACDF depends on intraoperative assessment supported by trials; however, there is currently no radiographic reference parameter that could aid in allograft height selection for improved outcomes. METHODS: A total of 148 patients who underwent ACDF using allografts and were followed up for more than 1 year were retrospectively reviewed. Fusion rates, subsidence, segmental lordosis, and foraminal height were assessed. Segments were divided into 2 groups according to whether the inserted allograft height was within 1 mm from the following 3 reference radiographic parameters: (1) uncinate process height, (2) adjacent disc height, and (3) preoperative disc height +2 mm. RESULTS: This study included 101 patients with 163 segments. Segments with an allograft-uncinate height difference of ≤1 mm had a significantly higher fusion rate at 1-year follow-up compared with segments with allograft-uncinate height difference of >1 mm [85/107 (79.4%) vs. 35/56 (62.5%); P =0.025]. Subsidence, segmental lordosis, and foraminal height did not significantly differ between the groups when segments were divided according to uncinate height. Multivariate logistic regression analysis demonstrated that allograft-uncinate height difference of ≤1 mm and allograft failure were factors associated with fusion. CONCLUSIONS: The uncinate process height can guide optimal allograft height selection for ACDF. Using an allograft with an allograft-uncinate height difference of ≤1 mm resulted in a higher fusion rate. Therefore, the uncinate process height should be checked preoperatively and used in conjunction with intraoperative assessment when selecting allograft height.

Mid-term efficacy and safety of Escherichia coli-derived rhBMP-2/hydroxyapatite carrier in lumbar posterolateral fusion: a randomized, multicenter study.

PURPOSE: This study aimed to evaluate the mid-term efficacy and safety of Escherichia coli-derived bone morphogenetic protein-2 (E.BMP-2)/hydroxyapatite (HA) in lumbar posterolateral fusion (PLF). METHODS: This multicenter, evaluator-blinded, observational study utilized prospectively collected clinical data. We enrolled 74 patients who underwent lumbar PLF and had previously participated in the BA06-CP01 clinical study, which compared the short-term outcomes of E.BMP-2 with an auto-iliac bone graft (AIBG). Radiographs and CT scans were analyzed to evaluate fusion grade at 12, 24, and 36 months. Visual analog scale (VAS), Oswestry disability index (ODI), and Short Form-36 (SF-36) scores were measured preoperatively and at 36 months after surgery. All adverse events in this study were assessed for its relationship with E.BMP-2. RESULTS: The fusion grade of the E.BMP-2 group (4.91 ± 0.41) was superior to that of the AIBG group (4.25 ± 1.26) in CT scans at 36 months after surgery (p = 0.007). Non-union cases were 4.3% in the E.BMP-2 and 16.7% in the AIBG. Both groups showed improvement in pain VAS, ODI, and SF-36 scores when compared to the baseline values, and there were no statistically significant differences between the two groups. No treatment-related serious adverse reactions were observed in either group. No neoplasm-related adverse events occurred in the E.BMP-2 group. CONCLUSIONS: The fusion quality of E.BMP-2/HA was superior to that of AIBG. E.BMP-2/HA showed comparable mid-term outcomes to that of AIBG in terms of efficacy and safety in one-level lumbar PLF surgery.

Efficacy and safety of oblique posterior endplate resection for wider decompression (trumpet-shaped decompression) during anterior cervical discectomy and fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) provides a limited workspace, and surgeons often need to access the posterior aspect of the vertebral body to achieve sufficient decompression. Oblique resection of the posterior endplate (trumpet-shaped decompression [TSD]) widens the workspace, enabling removal of lesions behind the vertebral body. This study was conducted to evaluate the efficacy and safety of oblique posterior endplate resection for wider decompression. METHODS: In this retrospective study, 227 patients who underwent ACDF for the treatment of cervical myelopathy or radiculopathy caused by spondylosis or ossification of the posterior longitudinal ligament and were followed up for ≥ 1 year were included. Patient characteristics, fusion rates, subsidence, and patient-reported outcome measures, including the neck pain visual analog scale (VAS) score, arm pain VAS score, and Neck Disability Index (NDI), were assessed. Patients who underwent TSD during ACDF (TSD group) and those who underwent surgery without TSD (non-TSD group) were compared. RESULTS: Fifty-seven patients (25.1%) were included in the TSD group and 170 patients (74.9%) in the non-TSD group. In the TSD group, 28.2% ± 5.5% of the endplate was resected, and 26.0% ± 6.1% of the region behind the vertebral body could be visualized via the TSD technique. The resection angle was 26.9° ± 5.9°. The fusion rate assessed on the basis of interspinous motion, intragraft bone bridging, and extragraft bone bridging did not significantly differ between the two groups. Furthermore, there were no significant intergroup differences in subsidence. The patient-reported outcome measures at the 1-year follow-up were also not significantly different between the groups. CONCLUSIONS: TSD widened the workspace during ACDF, and 26% of the region posterior to the vertebral body could be accessed using this technique. The construct stability was not adversely affected by TSD as demonstrated by the similar fusion and subsidence rates among patients who underwent TSD and those who did not. Therefore, TSD can be safely applied during ACDF when compressive lesions extend behind the vertebral body and are not limited to the disc space, enabling adequate decompression without disrupting the construct stability.

Factors affecting the prognosis of recovery of motor power and ambulatory function after surgery for metastatic epidural spinal cord compression.

OBJECTIVE: Metastatic epidural spinal cord compression (MESCC) causes neurological deficits that may hinder ambulation. Understanding the prognostic factors associated with increased neurological recovery and regaining ambulatory functions is important for surgical planning in MESCC patients with neurological deficits. The present study was conducted to elucidate prognostic factors of neurological recovery in MESCC patients. METHODS: A total of 192 patients who had surgery for MESCC due to preoperative neurological deficits were reviewed. A motor recovery rate ≥ 50% and ambulatory function restoration were defined as the primary favorable endpoints. Factors associated with a motor recovery rate ≥ 50%, regaining ambulatory function, and patient survival were analyzed. RESULTS: About one-half (48.4%) of the patients had a motor recovery rate ≥ 50%, and 24.4% of patients who were not able to walk due to MESCC before the surgery were able to walk after the operation. The factors "involvement of the thoracic spine" (p = 0.015) and "delayed operation" (p = 0.041) were associated with poor neurological recovery. Low preoperative muscle function grade was associated with a low likelihood of regaining ambulatory functions (p = 0.002). Furthermore, performing the operation ≥ 72 hours after the onset of the neurological deficit significantly decreased the likelihood of regaining ambulatory functions (p = 0.020). Postoperative ambulatory function significantly improved patient survival (p = 0.048). CONCLUSIONS: Delayed operation and the involvement of the thoracic spine were poor prognostic factors for neurological recovery after MESCC surgery. Furthermore, a more severe preoperative neurological deficit was associated with a lesser likelihood of regaining ambulatory functions postoperatively. Earlier detection of motor weaknesses and expeditious surgical interventions are necessary, not only to improve patient functional status and quality of life but also to enhance survival.

The Kappa Line as a Regional Modification of the K-line: A Predictor of Neurological Outcome and Indicator of the Adequate Level of Decompression in Selective Laminoplasty.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: The aim was to introduce Kappa line (modification of K-line) for the prediction of postoperative neurological recovery after selective cervical laminoplasty (LMP) and use in determining the decompression level. SUMMARY OF BACKGROUND DATA: The K-line is a radiographic marker that can predict prognosis and aid in surgical planning for patients undergoing LMP through C3 to C7. However, its efficacy in LMP involving limited segments is unclear. Furthermore, no specific radiographic marker to predict the prognosis of selective LMP has been reported. MATERIALS AND METHODS: Fifty-one consecutive patients with a minimum 2-year follow-up after selective LMP for cervical myelopathy caused by ossification of posterior longitudinal ligament were retrospectively reviewed. The Kappa line was defined as a straight line connecting the midpoints of the spinal canal made by remaining bony structure after decompression procedures on a plain lateral radiograph in the neutral position. Patients were classified as K-line (+) or (-) and Kappa line (+) or (-) based on whether the ossified mass crossed the indicator line. RESULTS: The Kappa line (+) group demonstrated significantly higher Japanese Orthopaedic Association (JOA) recovery rate (P=0.01), final JOA score (P<0.01), and dural sac diameter (P<0.01) postoperatively than the Kappa line (-) group. Cord compression grade was significantly lesser in the Kappa line (+) group. However, the K-line-based classification did not demonstrate significant difference in JOA recovery rate, final JOA score, and cord compression grade between the (+) and (-) groups; the dural sac diameter was significantly higher in the K-line (+) group (P<0.01). CONCLUSIONS: The Kappa line showed better correlation with ossification of posterior longitudinal ligament size and cervical alignment, providing better prediction of neurological recovery and remaining cord compression following selective LMP. Therefore, the Kappa line can aid in determining the level of decompression in selective LMP.

Comparison between selective caudal fixed screw construct and all variable screw construct in anterior cervical discectomy and fusion.

This retrospective comparative study aimed to compare the efficacy of selective caudal fixed screw constructs with all variable screw constructs in anterior cervical discectomy and fusion (ACDF). Thirty-five patients who underwent surgery using selective caudal fixed screw construct (SF group) were compared with 44 patients who underwent surgery using all variable constructs (AV group). The fusion rate, subsidence, adjacent level ossification development (ALOD), adjacent segmental disease (ASD), and plate-adjacent disc space distance were assessed. The one-year fusion rates assessed by computed tomography bone bridging and interspinous motion as well as the significant subsidence rate did not differ significantly between the AV and SF groups. The ALOD and ASD rates and plate-adjacent disc space distances did not significantly differ between the two groups at both the cranial and caudal adjacent levels. The number of operated levels was significantly associated with pseudarthrosis in the logistic regression analysis. The stability provided by the locking mechanism of the fixed screw did not lead to an increased fusion rate at the caudal level. Therefore, the screw type should be selected based on individual patient's anatomy and surgeon's experience without concern for increased complications caused by screw type.

Feasibility of CaO-SiO2-P2O5-B2O3 Bioactive Glass Ceramic Cage in Anterior Cervical Diskectomy and Fusion.

BACKGROUND: CaO-SiO2-P2O5-B2O3 bioactive glass ceramic (BGC) is known to chemically bond with bones by forming a hydroxyapatite layer and inducing osteoblastic differentiation. This study was conducted to compare the clinical outcomes, radiographic outcomes, and safety of a CaO-SiO2-P2O5-B2O3 BGC cage in anterior cervical diskectomy and fusion (ACDF) with those of an allograft interbody spacer. METHODS: A total of 63 patients who underwent 2-level ACDF to treat degenerative cervical radiculopathy/myelopathy were reviewed. Results from 26 patients who were recruited prospectively using CaO-SiO2-P2O5-B2O3 BGC as a cage material (BGC group) were compared with a historical control group of 37 patients who underwent surgery using an allograft (allograft group). Fusion rates, subsidence, and adjacent segment degeneration were compared between the groups. Demographic data, fusion rates, visual analog scale (VAS) scores for neck or arm pain, Neck Disability Index (NDI) scores, and complications were also compared. RESULTS: Fusion rates were 88.5% when assessed by interspinous motion and 92.3% when assessed by intragraft bone bridging in the BGC group at 12-month follow-up. The neck pain or arm pain VAS scores and NDI scores significantly improved in both groups. No material-related complications were observed in the BGC group, such as graft resorption and breakage. Fusion rates, subsidence, neck pain or arm pain VAS scores, and NDI scores did not significantly differ between the BGC and allograft groups. CONCLUSIONS: CaO-SiO2-P2O5-B2O3 BGC cage was effective and safe when used in ACDF, conferring a high fusion rate and favorable clinical outcomes similar to those of the allograft.

Temporary Bridge Occipitocervical Fixation for Comminuted Atlantoaxial Fracture.

OBJECTIVE: We sought to evaluate the feasibility of temporary bridge occipitocervical fixation temporary bridge occipitocervical fixation (T-BOCF) for comminuted atlantoaxial fractures. METHODS: A 57-year-old man presented with multiple trauma including a comminuted, undisplaced atlantoaxial fracture; subdural hemorrhage; skull base fracture; scalp laceration; right second finger tendon injury; and right distal femur open fracture. T-BOCF was performed to preserve neck motion while providing rigid stability to atlantoaxial fracture. Occipital plate and bilateral lateral mass screws were inserted at C3, C4, and C5, avoiding the fracture site; this was followed by rod connection without fusion. The screw-rod construct was removed after confirmation of bone union in the fracture site 12 months after the initial operation. RESULTS: Computed tomography performed at 12 months after the operation demonstrated solid bone union. Dynamic radiographs taken 12 months after implant removal demonstrated a flexion-extension range of motion of 16 degrees at C0‒C2 and 19.8 degrees at C2‒C7. The total flexion-extension range of motion was 35.8 degrees. CONCLUSIONS: T-BOCF is a viable option for treatment of comminuted, undisplaced atlantoaxial fractures. The technique is easier than direct C1‒C2 fusion and can avoid complications associated with occipitocervical fusion or C1‒C2 screw fixation. The blood supply to the fracture site is preserved by avoiding subperiosteal stripping, and semispinalis cervicis insertion at the C2 spinous process is also circumvented. Furthermore, neck motion is preserved after implant removal.

Intradural Extramedullary Metastatic Conjunctival Malignant Melanoma.

BACKGROUND: Intradural extramedullary (IDEM) metastatic spine tumors of nonneurogenic origin, excluding leptomeningeal seeding, are very rare. Most patients with IDEM metastatic spine tumors of nonneurogenic origin have coexisting brain metastasis. We report a case of IDEM metastatic malignant melanoma without antecedent or coexisting brain metastasis. CASE DESCRIPTION: A 52-year-old man presented with back pain, numbness in the lower extremities, paraparesis, and residual urine sensation after voiding. The patient had a history of conjunctival melanoma in the left eye and underwent surgical removal 3 years 6 months ago. Whole-spine magnetic resonance imaging showed an IDEM tumor at the T11 and T12 level, with compression of the spinal cord. Total laminectomy and resection of the tumor was performed. Pathology confirmed a malignant melanoma. Postoperatively, adjuvant chemotherapy was performed. Pain and neurologic deficit gradually improved, but complete recovery was not achieved. CONCLUSIONS: Although rare, even without brain metastasis, malignant melanoma can cause IDEM metastatic malignant melanoma. For neurologic recovery and maintaining quality of life of the patient, surgical treatment for decompression of the spinal cord and postoperative adjuvant treatment for IDEM metastatic malignant melanoma should be considered unless multiple lesions are present in different parts within the spinal column.

What is the most accurate radiographic criterion to determine anterior cervical fusion?

BACKGROUND CONTEXT: The accuracy of radiographic criteria for determining anterior cervical fusion remains controversial, and inconsistency in the literature makes a comparison of published clinical results problematic. The descriptions of bridging bone are still lacking and subjective, and the interpretation of images can be influenced by the type of graft or cage used. PURPOSE: To assess and validate the diagnostic accuracies of four radiographic fusion criteria using the results of surgical exploration. STUDY DESIGN: Retrospective, radiographic, and comparative study. PATIENT SAMPLE: This study included patients who required anterior or posterior exploration of a previous anterior cervical arthrodesis level(s) ranging from C3-C4 to C7-T1 for suspected pseudarthrosis or adjacent-segment pathologies. They underwent radiologic examinations to determine the four fusion criteria. We included patients whose images were taken at least 1 year after the index surgery, and 82 patients with 151 cervical segments were enrolled. OUTCOME MEASURES: The inter- and intra-rater reliabilities and validity that correlated with the results of surgical exploration for the four fusion criteria were assessed using data (fusion or not) that were collected by two raters. METHODS: The four published radiographic fusion criteria were interspinous motion (ISM) < 1 mm and superjacent ISM ≥ 4 mm, seen on dynamic radiographs; conventional bridging bone, as seen on computed tomography (CT) scans; and extra-graft bridging bone (ExGBB) and intragraft bridging bone (InGBB), observed on multi-axial reconstructed CT scans. The criteria were evaluated by two raters (spine surgeons with 5 and 7 years of experience). The raters evaluated each criterion twice at two different time points, 3 to 4 weeks apart. First, ISM and conventional bridging bone on CT scans were evaluated, followed by ExGBB and InGBB, with a time interval of 4 months. This Research was supported by the Chung-Ang University Research Grants (less than 5,000 US dollars) in 2016. RESULTS: The inter- and intra-rater reliability values of the ExGBB (0.887-0.933) criteria were the highest, followed by those for the ISM (0.860-0.906), bridging bone (0.755-0.907), and InGBB (0.656-0.695) criteria. The validity values that correlated with the exploration results were the highest for the ExGBB criteria (k=0.889), followed by the ISM (k=0.776), bridging bone (k=0.757), and InGBB (k=0.656) criteria and ExGBB showed the highest sensitivity (91.7%) and specificity (98.4%). Regarding the graft materials that were used, all criteria had the highest values in the auto-cortical group and lowest values in the cage group. Of note, sensitivity and specificity of ExGBB were 100% in autocortical group. In the cage group, the validity values for the ExGBB (k=0.663) and ISM (k=0.666) criteria were higher than those for the bridging bone (k=0.504) and InGBB (k=0.308) criteria CONCLUSION: The presence of ExGBB (anterior, posterior, or lateral to the graft or cage) correlated the best with surgical exploration. The ISM criteria demonstrated a similar accuracy to that of conventional bridging bone criteria on CT scans. In arthrodesed segments with auto-cortical bone, criteria showed the highest validity values. In cage group, ISM and ExGBB had acceptable accuracy, but the conventional bridging bone and InGBB were worse than guessing. We recommend that ISM and ExGBB criteria should be used to increase accuracy in patients who undergo arthrodesis with cages.

Efficacy of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in posterolateral lumbar fusion: an open, active-controlled, randomized, multicenter trial.

BACKGROUND CONTEXT: The efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute in spinal fusion has been widely researched. However, no study of the efficacy and safety of Escherichia coli-derived rhBMP-2 (E.BMP-2) with a hydroxyapatite (HA) carrier has been proposed. PURPOSE: This study aimed to compare the efficacy and safety of fusion materials between E.BMP-2 and autogenous iliac bone graft in posterolateral fusion (PLF). STUDY DESIGN/SETTING: An open, active-controlled, randomized, multicenter trial was carried out. PATIENT SAMPLE: This study included 93 patients who underwent single-level lumbar or lumbosacral PLF. OUTCOME MEASURES: The primary outcome measure was computed tomography (CT)-based fusion rate at 12 and 24 weeks. Secondary outcome measures were fusion grade by radiographs and CT at 12 and 24 weeks and changes in Oswestry Disability Index (ODI), Short Form-36 (SF-36) Health Survey, and visual analogue scale (VAS). METHODS: Patients who underwent 1-level PLF (between L1 and S1) for severe spinal stenosis or grade 1 spondylolisthesis were randomized to receive E.BMP-2 with an HA carrier (E.BMP-2 group) or autogenous iliac bone graft (AIBG group). Thin-section CT (<2 mm), VAS, ODI, and SF-36 were obtained pre- and postoperatively at 12 and 24 weeks. Outcome measures were compared between the groups. RESULTS: A total of 100 patients were enrolled in this trial. Among them, 93 patients underwent planned surgery. Preoperative demographic and clinical data showed no difference between groups. CT-based fusion rates were 100.0% (41/41) for the E.BMP-2 group and 90.2% (46/51) for the AIBG group (p=.062) at 12 weeks and 100.0% (41/41) and 94.1% (48/51) (p=.251) at 24 weeks, respectively. Fusion grade based on radiographs and CT showed non-inferiority of the E.BMP-2 group compared with the AIBG group. All clinical parameters improved postoperatively. However, there was no difference in changes in VAS, ODI, or SF-36 between the groups. No serious adverse event related to E.BMP-2 was found. CONCLUSIONS: The fusion rate of E.BMP-2 was comparable with that of AIBG following PLF. Good clinical efficacy and safety of E.BMP-2 in spinal fusion were also revealed. It was also suggested that HA shows suitability as a carrier for E.BMP-2. Thus, E.BMP-2 with an HA carrier can be an alternative bone graft material in spinal fusion.

Comparison of fusion rate and clinical results between CaO-SiO2-P2O5-B2O3 bioactive glass ceramics spacer with titanium cages in posterior lumbar interbody fusion.

BACKGROUND CONTEXT: The CaO-SiO2-P2O5-B2O3 glass ceramics spacer generates chemical bonding to adjacent bones with high mechanical stability to produce a union with the end plate, and ultimately stability. PURPOSE: The authors aimed to compare the clinical efficacy and safety of CaO-SiO2-P2O5-B2O3 glass ceramics with a titanium cage that is widely used for posterior lumbar interbody fusion (PLIF) surgery in the clinical field. STUDY DESIGN/SETTING: This is a prospective, stratified randomized, multicenter, single-blinded, comparator-controlled non-inferiority trial. PATIENT SAMPLE: The present study was conducted in four hospitals and enrolled a total of 86 patients between 30 and 80 years of age who required one-level PLIF due to severe spinal stenosis, spondylolisthesis, or huge disc herniation. OUTCOME MEASURES: The Oswestry Disability Index (ODI), Short Form-36 Health Survey (SF-36), and pain visual analog scale (VAS) were assessed before surgery and at 3, 6, and 12 months after surgery. The spinal fusion rate was assessed at 6 and 12 months after surgery. METHODS: The spinal fusion rate and the area of fusion, subsidence of each CaO-SiO2-P2O5-B2O3 glass ceramics and titanium cage, and the extent of osteolysis were evaluated using a dynamic plain radiography and a three-dimensional computed tomography at 12 months after surgery. The present study was supported by BioAlpha, and some authors (JHL, C-KL, and B-SC) have stock ownership (<10,000 US dollars). RESULTS: From the plain radiography results, the 6-month fusion rates for the bioactive glass ceramics group and the titanium group were 89.7% and 91.4%, respectively. In addition, the 12-month fusion rates based on CT scan were 89.7% and 91.2%, respectively, showing no significant difference. However, the bone fusion area directly attached to the end plate of either bioactive glass ceramics or the titanium cage was significantly higher in the bioactive glass ceramics group than in the titanium group. The ODI, SF-36, back pain, and lower limb pain in both groups significantly improved after surgery, with no significant differences between the groups. No significant differences between the two groups were observed in the extent of subsidence and osteolysis. CONCLUSIONS: In lumbar posterior interbody fusion surgery, CaO-SiO2-P2O5-B2O3 glass ceramics spacer showed a similar fusion rates and clinical outcomes compared with titanium cage.

Prognostic Factors for Postsurgical Recovery of Deltoid Palsy due to Cervical Disc Herniations.

STUDY DESIGN: Retrospective multicenter study. PURPOSE: We aimed to investigate prognostic factors affecting postsurgical recovery of deltoid palsy due to cervical disc herniation (CDH). OVERVIEW OF LITERATURE: Little information is available about prognostic factors affecting postsurgical recovery of deltoid palsy due to CDH. METHODS: Sixty-one patients with CDH causing deltoid palsy (less than grade 3) were included in this study: 35 soft discs and 26 hard discs. Average duration of preoperative deltoid palsy was 11.9 weeks. Thirty-two patients underwent single-level surgery, 22 two-level, four three-level, and three four-level. Patients with accompanying myelopathy, shoulder diseases, or peripheral neuropathy were excluded from the study. RESULTS: Deltoid palsy (2.4 grades vs. 4.5 grades, p<0.001) and radiculopathy (6.4 points vs. 2.1 points, p<0.001) significantly improved after surgery. Thirty-six of 61 patients (59%) achieved full recovery (grade 5) of deltoid palsy, with an average time of 8.4 weeks. Longer duration of preoperative deltoid palsy and more severe radiculopathy negatively affected the degree of improvement in deltoid palsy. Age, gender, number of surgery level, and disc type did not affect the degree of improvement of deltoid palsy. Contrary to our expectations, severity of preoperative deltoid palsy did not affect the degree of improvement. Due to the shorter duration of preoperative deltoid palsy, in the context of rapid referral, early surgical decompression resulted in significant recovery of more severe grades (grade 0 or 1) of deltoid palsy compared to grade 2 or 3 deltoid palsy. CONCLUSIONS: Early surgical decompression significantly improved deltoid palsy caused by CDH, irrespective of age, gender, number of surgery level, and disc type. However, longer duration of deltoid palsy and more severe intensity of preoperative radiating pain were associated with less improvement of deltoid palsy postoperatively.

Early postoperative analgesic effects of a single epidural injection of ropivacaine administered preoperatively in posterior lumbar interbody spinal arthrodesis: a pilot randomized controlled trial.

BACKGROUND: Despite the suitable characteristics of ropivacaine as an epidural analgesic agent, such as better preservation of motor function and less neurotoxicity, we are aware of no data on its clinical application in pain management following lumbar spine surgery. The purpose of the present study was to evaluate the preemptive analgesic effects and safety of a single epidural injection of ropivacaine during lumbar arthrodesis. METHODS: We performed a randomized, double-blinded, intention-to-treat study. Patients with planned one-level posterior lumbar interbody arthrodesis were randomly assigned to either the injection group (n = 32) or the control group (n = 34). The injection group received a 10-mL epidural injection of 0.1% ropivacaine twenty minutes before the skin incision at the planned vertebral level, and the control group received an epidural injection of 10 mL of 0.9% saline solution. A numeric rating scale (from 0 to 10) was measured at seven time points after surgery (at two, four, eight, twelve, twenty-four, and forty-eight hours and at the time of discharge), and the frequency of pushed-button patient-controlled analgesia and total fentanyl consumption were assessed at similar time points (up to two, up to four, up to eight, up to twelve, up to twenty-four, and up to forty-eight hours after surgery). Postoperative nausea and vomiting, the duration of the hospital stay, and the Likert satisfaction score at the time of discharge were evaluated. RESULTS: There were no significant differences between the two groups preoperatively. The numeric rating scale score was higher until twelve hours (p < 0.05) and the frequency of button pushes was higher at every time point except eight to twelve hours (p < 0.05) in the control group as compared with the injection group. Fentanyl consumption until eight to twelve hours (p < 0.05) and total consumption (p < 0.001) at discharge were higher in the control group. There were no differences between the two groups in terms of postoperative nausea and vomiting, the duration of hospital stay, or the mean satisfaction score, and no transient motor weakness was seen in relation to epidural injection of ropivacaine. CONCLUSIONS: A single-dose epidural injection of 0.1% ropivacaine before lumbar spine surgery is effective for reducing early postoperative pain without related complications such as transient motor weakness.

Subsidence and nonunion after anterior cervical interbody fusion using a stand-alone polyetheretherketone (PEEK) cage.

BACKGROUND: The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications. METHODS: Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs. RESULTS: The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001). CONCLUSIONS: Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.

Comparison of joint line position changes after primary bilateral total knee arthroplasty performed using the navigation-assisted measured gap resection or gap balancing techniques.

PURPOSE: This study aimed to compare the clinical and radiological results of navigation-assisted TKAs performed using the measured gap resection or the gap balancing technique in thirty patients who underwent bilateral primary TKAs. METHODS: Sixty cases of navigation-assisted TKAs [30 TKAs performed using the measured gap resection technique (Group A) and 30 TKAs performed using the gap balancing technique (Group B)] were analyzed prospectively with minimum follow-up of 2 years. The joint line positions were measured using preoperative and postoperative weight-bearing anteroposterior and lateral radiographs. Clinical results were evaluated using knee scores and functional scores. RESULTS: No significant differences in knee scores or functional scores were observed. Polyethylene thickness and flexion/extension gaps were significantly larger in Group B (P < 0.05). The meaningful proximal shift of the joint line was shown in Group B (P < 0.05). CONCLUSION: The navigation-assisted TKA with measured gap resection technique could be a useful technique with regard to restoration of the joint line.

Acutely progressing paraplegia caused by traumatic disc herniation through posterior Schmorl's node opening into the spinal canal in lumbar Scheuermann's disease.

STUDY DESIGN: A case report. OBJECTIVE: To report an unusual neurologic complication caused by traumatic disc herniation through atypical posterior Schmorl's node (SN) opening into the spinal canal in lumbar Scheuermann's disease. SUMMARY OF BACKGROUND DATA: Neurologic complications in Scheuermann's disease are rare and disc hernia has been reported as one of the causes of neural compression. However, there has been no report on acutely progressing paraplegia caused by traumatic disc herniation through an atypical posterior SN opening into the spinal canal in lumbar Scheuermann's disease. METHODS: A clinical and radiologic review of such a case of traumatic disc herniation through an atypical posterior SN that resulted in acutely progressing paraplegia in Scheuermann's disease was performed. RESULTS: The patient presented with severe back pain after a fall, without any neurologic abnormalities. Computed tomographic scan revealed lumbar Scheuermann's disease, acute compression fracture of T12, and a large posterior SN with "trough-like" indentation of the lower endplate of T12 opening into the spinal canal. Abruptly progressing paraplegia occurred in less than 24 hours after the first visit and the magnetic resonance imaging revealed severe spinal cord compression by large disc extrusion with superior migration at T12-L1 through the atypical posterior SN at the lower endplate of T12. The patient underwent posterior decompression and discectomy at T12-L1 through transfacet pedicle-sparing approach. Postoperatively, the patient showed immediate improvement in the sensory deficit on L1 dermatome and the perianal area and motor function of the hip flexors to grade 2 without further neurologic improvement, at 2-year follow-up. CONCLUSION: The case report highlights the clinical significance of the atypical posterior SN that could be a channel for large disc extrusion after a traumatic event in Scheuermann's disease and the clinical importance of surgeon's close attention to the possibility of abruptly progressing neurologic compromise in this situation.