Clinical and Radiological Outcomes in C2 Recapping Laminoplasty for the Pathologies in the Upper Cervical Spine.

OBJECTIVE: To evaluate C2 muscle preservation effect and the radiological and clinical outcomes after C2 recapping laminoplasty. METHODS: Fourteen consecutive patients who underwent C2 recapping laminoplasty around C1-2 level were enrolled. To evaluate muscle preservation effect, the authors conducted a morphological measurement of extensor muscles between the operated and nonoperated side. Two surgeons measured the cross-sectional area (CSA) of obliquus capitis inferior (OCI) and semispinalis cervicis (SSC) muscle before and after surgery to determine atrophy rates (ARs). Additionally, we examined range of motion (ROM), sagittal vertical axis (SVA), neck visual analogue scale (VAS), Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) score to assess potential changes in alignment and consequent clinical outcomes following posterior cervical surgery. RESULTS: We measured the CSA of OCI and SSC before surgery, and at 6 and 12 months postoperatively. Based on these measurements, the AR of the nonoperated SSC was 0.1% ± 8.5%, the AR of the operated OCI was 2.0% ± 7.2%, and the AR of the nonoperated OCI was -0.7% ± 5.1% at the 12 months after surgery. However, the AR of the operated side's SSC was 11.2% ± 12.5%, which is a relatively higher value than other measurements. Despite the atrophic change of SSC on the operated side, there were no prominent changes observed in SVA, C0-2 ROM, and C2-7 ROM between preoperative and 12 months postoperative measurements, which were 11.8 ± 10.9 mm, 16.3° ± 5.9°, and 48.7° ± 7.7° preoperatively, and 14.1 ± 11.6 mm, 16.1° ± 7.2°, and 44.0° ± 10.3° at 12 months postoperative, respectively. Improvement was also noted in VAS, NDI, and JOA scores after surgery with JOA recovery rate of 77.3% ± 29.6%. CONCLUSION: C2 recapping laminoplasty could be a useful tool for addressing pathologies around the upper cervical spine, potentially mitigating muscle atrophy and reducing postoperative neck pain, while maintaining sagittal alignment and ROM.

Do Obliquity and Position of the Oblique Lumbar Interbody Fusion Cage Influence the Degree of Indirect Decompression of Foraminal Stenosis?

OBJECTIVE: Oblique lumbar interbody fusion (OLIF) is a surgical technique that utilizes a large interbody cage to indirectly decompress neural elements. The position of the cage relative to the vertebral body could affect the degree of foraminal decompression. Previous studies determined the position of the cage using plain radiographs, with conflicting results regarding the influence of the position of the cage to the degree of neural foramen decompression. Because of the cage obliquity, computed tomography (CT) has better accuracy than plain radiograph for the measurement of the obliquely inserted cage. The objective of this study is to find the correlation between the position of the OLIF cage with the degree of indirect decompression of foraminal stenosis using CT and magnetic resonance imaging (MRI). METHODS: We review imaging of 46 patients who underwent OLIF from L2-L5 for 68 levels. Segmental lordosis (SL) was measured in a plain radiograph. The positions of the cage were measured in CT. Spinal canal cross-sectional area (SCSA), and foraminal crosssectional area (FSCA) measurements using MRI were taken into consideration. RESULTS: Patients' mean age was 69.7 years. SL increases 3.0±5.1 degrees. Significant increases in SCSA (33.3%), FCSA (43.7% on the left and 45.0% on the right foramen) were found (p<0.001). Multiple linear regression analysis shows putting the cage in the more posterior position correlated with more increase of FSCA and decreases SL correction. The position of the cage does not affect the degree of the central spinal canal decompression. Obliquity of the cage does not result in different degrees of foraminal decompression between right and left side neural foramen. CONCLUSION: Cage position near the posterior part of the vertebral body increases the decompression effect of the neural foramen while putting the cage in the more anterior position correlated with increases SL.

Influence of dynamic neck motion on the clinical usefulness of multi-positional MRI in cervical degenerative spondylosis.

PURPOSE: The purpose of this study was to find out additional indications for multi-positional MRI in cervical degenerative spondylosis (CDS) patients. MATERIAL AND METHODS: A total of 63 patients with cervical spondylotic myelopathy that underwent multi-positional MRI and X-ray were included. Muhle's grade, C2-7 angle, and C7 slope were measured. Patients were assigned to the stenosis group (Group S) when Muhle's grades were increased by more than two or maximum grade was reached. Other patients were assigned to the maintenance group (Group M). Receiver operating characteristic (ROC) analysis was performed. Statistical significance was accepted for p values of < 0.05. RESULTS: A total of 24 patients were assigned to the S group and 39 patients to the M group. Mean C2-7 angle difference in extension (eC27A) between S and M groups was 10.97° (p = 0.002). The mean inter-group difference between C2-7 angle in extension and neutral positions (e-nC27A) was 14.39° (p = 0.000). Mean C7 slope difference in neutral position was - 6.53° (p = 0.002). Based on areas under ROC curves (AUCs), e-nC27A, eC27A, and negative C7 slope had AUCs of 0.934 (95% CI 0.876-0.992), 0.752 (95% CI 0.624-0.880), and 0.720 (95% CI 0.588-0.851), respectively. The optimal cutoff value of e-nC27A was 15.4 degrees, which had a diagnostic accuracy of 88.9%. CONCLUSION: Multi-positional MRI helps to find dynamic cord compressive lesion in CDS patients. The higher eC27A, e-nC27A values and smaller C7 slope were found to increase the likelihood of cervical dynamic stenosis. Among other factors, we recommend multi-positional MRI before surgery especially when a patient's e-nC27A is > 15.4 degrees. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Intraoperative surveillance of the vertebral artery using indocyanine green angiography and Doppler sonography in craniovertebral junction surgeries.

OBJECTIVE: The authors sought to evaluate the usefulness of indocyanine green (ICG) angiography and Doppler sonography for monitoring the vertebral artery (VA) during craniovertebral junction (CVJ) surgery and compare the incidence of VA injury (VAI) between the groups with and without the monitoring of VA using ICG angiography and Doppler sonography. METHODS: In total, 344 consecutive patients enrolled who underwent CVJ surgery. Surgery was performed without intraoperative VA monitoring tools in 262 cases (control group) and with VA monitoring tools in 82 cases (monitoring group). The authors compared the incidence of VAI between groups. The procedure times of ICG angiography, change of VA flow velocity measured by Doppler sonography, and complication were investigated. RESULTS: There were 4 VAI cases in the control group, and the incidence of VAI was 1.5%. Meanwhile, there were no VAI cases in the monitoring group. The procedure time of ICG angiography was less than 5 minutes (mean [± SD] 4.6 ± 2.1 minutes) and VA flow velocity was 11.2 ± 4.5 cm/sec. There were several cases in which the surgical method had to be changed depending on the VA monitoring. The combined use of ICG angiography and Doppler sonography was useful not only to monitor VA patency but also to assess the quality of blood flow during CVJ surgery, especially in the high-risk group of patients. CONCLUSIONS: The combined use of ICG angiography and Doppler sonography enables real-time intraoperative monitoring of the VA by detecting blood flow and flow velocity. As the arteries get closer, they provide auditory and visual feedback to the surgeon. This real-time image guidance could be a useful tool, especially for high-risk patients and inexperienced surgeons, to avoid iatrogenic VAI during any CVJ surgery.

Comparative Analysis of 2 Different Types of Titanium Mesh Cage for Single-level Anterior Cervical Corpectomy and Fusion in Terms of Postoperative Subsidence and Sagittal Alignment.

STUDY DESIGN: This was a retrospective observatory analysis study. OBJECTIVE: The objective of this study was to compare the differences in clinical and radiologic outcomes among patients who underwent anterior cervical corpectomy and fusion (ACCF) using titanium mesh cage (TMC) with end-caps and patients who underwent ACCF using TMC without end-cap. SUMMARY OF BACKGROUND DATA: TMC has been widely used as an effective treatment option for ACCF. However, the subsidence of TMC has been observed frequently in the early postoperative period in some cases, resulting in related clinical complications. MATERIALS AND METHODS: Patients who underwent single-level ACCF using TMC from September 2008 to June 2014 at our institute were retrospectively reviewed. Patients treated with TMC with end-cap were classified as an end-cap group, while patients treated with TMC without end-cap classified as a control group. The round press-fit-type end-caps with 2.5-degree angulation were used at both ends of the cage for the end-cap group. Patients were followed postoperatively for a minimum of 36 months with radiologic evaluation. RESULTS: The subsidence was lower in the end-cap group (4.3±3.6 vs. 4.8±3.0, P<0.01), with lower rates of severe subsidence (≥3 mm) than the control group (34.2% vs. 52.1%, P<0.01). Visual analogue scale (VAS) scores for neck pain and Neck Disability Index (NDI) was reported significantly less in the study group, which showed a positive correlation with lesser severe subsidence. Also, the characteristics of subsidence differed between the 2 groups. In the end-cap group, slippage type subsidence occurred, resulting in better sagittal alignment than that in the control group. CONCLUSIONS: For patients undergoing single-level ACCF, using TMC with end-cap provided better clinical results and similar fusion rate, compared with using TMC without end-cap. The end-cap decreased the severity of postoperative subsidence and related neck pain. Also, sagittal alignment was well preserved, suggesting it may contribute to cervical lordosis.

Epidemiology of C5 Palsy after Cervical Spine Surgery: A 21-Center Study.

OBJECTIVE: C5 palsy is a severe complication after cervical spine surgery, the pathophysiology of which remains unclear. This multicenter study investigated the incidence of C5 palsy following cervical spine surgery in Korea. METHODS: We conducted a retrospective multicenter study involving 21 centers from the Korean Cervical Spine Study Group. The inclusion criteria were cervical spine surgery patients between 2012 and 2016, excluding cases of neck surgery. In patients with C5 palsy, the operative methods, disease category, onset time of C5 palsy, recovery time, C5 manual muscle testing (MMT) grade, and post-C5 palsy management were analyzed. RESULTS: We collected 15,097 cervical spine surgery cases from 21 centers. C5 palsy occurred in 88 cases (0.58%). C5 palsy was more common in male patients (p=0.019) and after posterior approach procedures (p<0.001). C5 palsy usually occurred within 3 days after surgery (77 of 88, 87.5%) and most C5 palsy patients recovered within 6 months (51 of 88, 57.95%). Thirty C5 palsy patients (34.09%) had motor weakness, with an MMT grade≤2. Only four C5 palsy patients (4.5%) did not recover during follow-up. Posterior cervical foraminotomy was performed in 7 cases (7.95%), and steroids were used in 56 cases (63.63%). Twenty-six cases (29.55%) underwent close observation only. CONCLUSION: The overall incidence of C5 palsy was relatively low (0.58%). C5 palsy was more common after posterior cervical surgery and in male patients. C5 palsy usually developed within 3 days after surgery, and more than half of patients with C5 palsy recovered within 6 months.

Clinical Characteristics and Outcomes of Patients with Culture-Negative Pyogenic Spondylitis according to Empiric Glycopeptide Use.

BACKGROUND: The optimal choice of antibiotics is challenging in culture-negative pyogenic spondylitis (PS). The empiric use of glycopeptides is suggested depending on various risk factors, although clinical data are sparse. This study aimed to analyze the clinical characteristics and outcomes of patients with culture-negative PS and evaluate the effect of empiric glycopeptide use on clinical outcomes in these patients. MATERIALS AND METHODS: Data on the characteristics, treatment, and outcomes of 175 patients diagnosed with PS were retrospectively obtained from the electronic database of a tertiary referral hospital from 2009 to 2016. Patients with negative culture results were grouped by the duration of glycopeptide treatment: glycopeptide therapy <28 days (Group A) and glycopeptide therapy ≥28 days (Group B). RESULTS: Of 89 patients with negative culture results, 78 were included in the analysis (Group A, n = 66; Group B, n = 12). The mean age of patients with negative culture results was 65.5 years, and 52.6% were male. The median follow-up duration was 573 (interquartile range [IQR], 83 - 1,037) days. The duration of intravenous glycopeptide therapy was 0.0 (IQR, 0.0 - 0.0) days and 55.5 (IQR, 37.0 - 75.7) days for Groups A and B, respectively. Patients who used glycopeptide longer empirically (Group B) had more commonly undergone a previous spinal procedure, including surgery (P = 0.024). The length of hospitalization, erythrocyte sedimentation rate, and C-reactive protein level were significantly higher in Group B compared with those in Group A (P <0.001, P <0.001, and P = 0.006, respectively). Regarding treatment modalities, patients in Group B underwent surgery more frequently (P = 0.017). The duration of parenteral antibiotic treatment was longer in Group B (P <0.001). Recurrence was noted in 7 patients (9.0%), and the recurrence rate was not significantly different between the 2 groups (Group A, 5/66 [7.6%]; Group B, 2/12 [16.7%]; P = 0.293). CONCLUSION: The recurrence rate among patients with culture-negative PS was not different based on the duration of empiric glycopeptide use. However, considering the small sample size and heterogeneity of our study population, we suggest that it is reasonable to administer glycopeptide antibiotics in these patients depending on clinical risk factors. Further large-scale prospective studies are needed to obtain more evidence for appropriate antibiotic treatment.

Full-endoscopic interlaminar discectomy for the treatment of a dorsal migrated thoracic disc herniation: Case report.

RATIONALE: Thoracic disc herniation (TDH) is an infrequent spinal disease and difficult to treat well. Various surgical approaches and procedures were introduced in many literatures. The authors report a patient with dorsal migrated TDH compressing the spinal cord at T10-11 level. PATIENT CONCERNS: A 65-year-old male patient presented with complaints of severe paresthesia of both legs and progressive motor weakness for 1 week. DIAGNOSES: Magnetic resonance imaging (MRI) of the thoracic and lumbar spine revealed TDH and migration of dorsal side on spinal cord at T10-11 level. INTERVENTIONS: Successful decompressive surgery was performed through a posterior interlaminar approach using only endoscopic instruments. OUTCOMES: After the operation, patient's symptoms, paraparesis and paresthesia, immediately improved. LESSONS: The successful results of this case suggest that full endoscopic laminotomy and discectomy may be an attractive minimally invasive surgical technique for treating TDH with dorsal migrated fragments.

Time Course Observation of Outcomes between Minimally Invasive Transforaminal Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion.

The purpose of this study is to compare the long-term patient-outcomes, spinal fusion, and incidence of adjacent segment degeneration (ASD) between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and open posterior lumbar interbody fusion (O-PLIF). We retrospectively reviewed 70 consecutive cases who underwent single-level MIS-TLIF or O-PLIF from March 2010 to July 2013. All the patients achieved a minimum of 5-year follow-up. Data collected for each patient included demographic data, perioperative data, and complications. Clinical outcomes were evaluated with Oswestry disability index and visual analogue scale (VAS). Radiological outcomes included fusion rate and ASD. About 34 patients of MIS-TLIF and 36 patients of O-PLIF were enrolled. Higher Charlson comorbidity index scores were noted in MIS-TLIF than in O-PLIF. Blood loss was significantly lower in MIS-TLIF than O-PLIF. There were significant improvements in clinical and radiological outcomes in both groups. At 6 months, in MIS-TLIF group had significantly lower VAS for back pain and disc height compared with in O-PLIF group. The fusion rate was similar between the two groups at 5-year follow-up. Although the total complication rates were similar between the two groups, both the incidence of ASD was significantly higher in O-PLIF group than MIS-TLIF group (P = 0.032). In conclusion, this study indicates that MIS-TLIF is comparable to O-PLIF in terms of fusion rates and clinical outcomes in single-segment degenerative lumbar diseases. In addition, compared with O-PLIF, MIS-TLIF has the advantages of lesser blood loss, faster recovery, and lower incidence of ASD.

Accuracy and Safety in Screw Placement in the High Cervical Spine: Retrospective Analysis of O-arm-based Navigation-assisted C1 Lateral Mass and C2 Pedicle Screws.

STUDY DESIGN: This study was a retrospective analysis. OBJECTIVE: The purpose of present study was to evaluate accuracy, efficiency, and safety of intraoperative O-arm-based navigation system for the placement of C1 lateral mass screw (C1LMS) and C2 pedicle screws (C2PSs) in high cervical spine operations. SUMMARY OF BACKGROUND DATA: High screw misplacement rates, various pedicle morphometry and vertebral body size variations have led to a search of image-guided systems to improve the surgical accuracy of screw insertion in high cervical spine. The use of O-arm has been proposed for more accurate and efficient spinal instrumentation. MATERIALS AND METHODS: Between June 2009 and August 2016, a total of 48 patients with atlantoaxial instability were surgically treated using the image-guidance system. To reconstruct atlantoaxial instability, we have been using Harm's technique of C1LMS and C2PS fixations. A frameless, stereotactic O-arm-based image-guidance system was used for correct screw placement. Postoperative computed tomographic scan with multiplanar reconstructions were used to determine the accuracy of the screw placement. RESULTS: A total of 182 screws, including 90 C1LMS and 92 C2PSs were inserted using image-guidance system. In total, 4.4% (4/90) of C1LMS and 7.6% (10/92) of C2PS had cortex violation over 2 mm and considered as "significant." Among the significant cortex violations, "unexpected breech" was 3.3% of all the screws inserted. Two (2.1%) screws inserted had perforated the vertebral artery canal and iatrogenic vertebral artery stenosis was proved with postoperative computed tomography angiography. When divided into time periods, 60% of significant breech occurred during the beginning stage, 40% during adaptation stage and none during expert stage. CONCLUSIONS: In this study, the authors demonstrated that use of image-guidance system seems to be beneficial for high cervical instrumentation which requires much experience and steep learning curves. However, incidence of cortex violation does not disappear completely due to the close proximity to spinal canal and surrounding vessels.