Qingying Hao

Comparison of Anterior Decompression and Fusion With Posterior Laminoplasty for Multilevel Cervical Compressive Myelopathy: A Systematic Review and Meta-Analysis.

Study Design: Systematic review and meta-analysis. Objective: To evaluate anterior decompression and fusion compared with posterior laminoplasty when treating multilevel cervical compressive myelopathy. Summary of Background Data: Satisfactory results have been reported with both anterior decompression and fusion and posterior laminoplasty in the treatment of multilevel cervical compressive myelopathy. However, which method is safer and more effective remains controversial. Methods: MEDLINE, EMASE, and the Cochrane library databases were searched for relevant controlled studies up to December 2014 that compared anterior decompression and fusion with posterior laminoplasty for the treatment of multilevel cervical compressive myelopathy. The following outcome measures were extracted for analysis: preoperative and postoperative Japanese Orthopedic Association scores, neurological recovery rate, preoperative and postoperative overall Cobb angle, blood loss, operative time, surgical complications, and reoperation rate. Results: A total of 19 studies representing 1279 patients were included in this analysis. The results indicated that anterior decompression and fusion was associated with better postoperative neurological function (P=0.001), a higher recovery rate (P<0.01), and better cervical alignment (P<0.01) than posterior laminoplasty in the treatment of multilevel cervical compressive myelopathy. However, anterior decompression and fusion was also associated with higher postoperative complication (P<0.01) and reoperation (P<0.01) rates. Intraoperative blood loss (P<0.01) was higher and operative times (P<0.01) were longer in the anterior decompression and fusion group compared with the posterior laminoplasty group. Conclusion: On the basis of this meta-analysis, anterior decompression and fusion is associated with better recovery of neurological function, better postoperative cervical alignment, higher postoperative complication and reoperation rates, more blood loss, and longer operative times compared with posterior laminoplasty.

Footprint Mismatch of Cervical Disc Prostheses with Chinese Cervical Anatomic Dimensions

Background: The footprint of most prostheses is designed according to Caucasian data. Total disc replacement (TDR) has been performed widely for cervical degenerative diseases in China. It is essential to analyze the match sizes of prostheses footprints and Chinese cervical anatomic dimensions in our study. Methods: The anatomic dimensions of the C4–C7 segments of 138 patients (age range 16–77 years) in a Chinese population were measured by computed tomography scans. We compared the footprints of the most commonly used cervical disc prostheses (Bryan: Medtronic, Minneapolis, MN, USA; Prestige LP: Medtronic, Fridley, Minnesota, USA; Discover: DePuy, Raynham, MA, USA; Prodisc-C: Synthes, West Chester, PA, USA) in China with Chinese cervical anatomic dimensions and assessed the match of their size. Results: The mismatch of available dimensions of prostheses and anatomic data of cervical endplates ranged from 17.03% (C4/C5, Prestige LP, Prodisc-C) to 57.61% (C6/C7, Discover) in the anterior-posterior (AP) diameter, and 35.51% (C4/C5, Prodisc-C, Prestige LP) to 94.93% (C6/C7, Bryan) in the center mediolateral (CML) diameter. About 21.01% of endplates were larger than the largest prostheses in the AP diameter and 57.25% in the CML diameter. All available footprints of prostheses expect the Bryan with an unfixed height, can accommodate the disc height (DH), however, 36.23% of the middle DH was less than the smallest height of the prostheses. The average disc sagittal angles (DSAs) of C4–C7 junctions were 5.04°, 5.15°, and 4.13° respectively. Only the Discover brand had a built-in 7° lordotic angle, roughly matching with the DSA. Conclusions: There is a large discrepancy between footprints of prostheses and Chinese cervical anatomic data. In recent years, possible complications of TDR related with mismatch sizes are increasing, such as subsidence, displacement, and heterotopic ossification. Manufacturers of prostheses should introduce or produce additional footprints of prostheses for Chinese TDR.

Palliative Surgery for Spinal Metastases Using Posterior Decompression and Fixation combined with Intra-operative Vertebroplasty.

Study Design: Retrospective study. Objective: To evaluate the clinical outcome of palliative surgery using posterior decompression and fixation combined with intraoperative vertebroplasty (PDFIV) for the treatment of spinal metastases, and analyze the indications for PDFIV using a neurological, oncologic, mechanical, and systemic framework. Summary of Background Data: Palliative surgery is widely used to spinal metastatic patients with poor condition for enough postoperative recovery. PDFIV which is a new palliative surgery is rarely reported its efficacies and indications. Methods: A retrospective analysis of 26 consecutive patients with spinal metastases treated by PDFIV was performed. The group includes 18 men and 8 women with an average age of 55.7 years (range, 47–79 y). All patients presented with local pain, 18 patients had compressive myelopathy, and 9 had radiculopathy. The total segments involved were 32. Postoperative imaging was used to evaluate cement leakage, the status of fixation, and recurrence. The visual analogue score and Frankel grade were used to identify neurological function. Results: There were no intraoperative neurological or vascular injuries. The mean operative time was 173 minutes (range, 125–245 min), the mean blood loss was 659 mL (range, 350–2500 mL), and the average amount of cement used in the vertebrae was 4.1 mL (range, 2.0–5.5 mL). All patients were followed for an average of 25 months (range, 6–56 mo). The visual analogue score decreased from 8.1 preoperatively to 2.1 postoperatively. Fifteen of 18 patients with compressive myelopathies had improved Frankel grades. Postoperative computed tomography scans showed cement leakage in 3 patients (11.5%); however, all of the leakages were clinically asymptomatic. There were local tumor recurrences requiring reoperation in 2 patients. Conclusions: Palliative surgery using PDFIV can improve neurological function and alleviate pain effectively, and allow low cement leakage and timely disposal of leakage combined with intraoperative visual vertebroplasty.

Clinical application of the "pedicle exposure technique" for atlantoaxial instability patients with a narrow c1 posterior arch.

Study Design: This was a retrospective study. Objective: The aim of this study was to test a new surgical approach, that is, “pedicle exposure technique,” for atlantoaxial instability (AAI) patients with C1 posterior arches measuring <4 mm, and to determine its feasibility and clinical outcomes. Summary of Background Data: C1 posterior arch screw placement is one of the most effective methods for AAI; however, several studies showed this method to be restricted when the posterior arch measures <4 mm. Hence, modification of this technique is necessary to expand its indications. Patients and Methods: The average height of the C1 posterior arch in 79 AAI cases was 3.3 (range, 2.5–3.9) mm. All patients were treated by the C1 “pedicle exposure technique” and C2 pedicle screw fixation. The feasibility and clinical outcome of this technique were analyzed by postoperative x-rays, computed tomography, and Visual Analogue Score and Japan Department of Orthopedics Association score. Results: A total of 158 screws were successfully placed into the atlas in all 79 patients. There were no vertebral artery or spinal cord injuries. Venous plexus bleeding was encountered in 3 patients; there were no cases of new onset occipital neuralgia. Three screws penetrated into the external wall of the C1 lateral mass and 4 screws into the internal wall. Seventy-nine patients were followed up for 6–80 months. Bony fusion was confirmed in all cases within 3–6 months by computed tomography; there were no instrument failures. Significant differences in preoperative and postoperative Visual Analogue Score and Japan Department of Orthopedics Association score were found. Thirty-six and 15 of 62 patients with preoperative neck pain had alleviation or resolution of symptoms, respectively; 33 of 36 patients with myelopathy demonstrated significant improvement. Conclusions: The “pedicle exposure technique” is an effective alternative in patients with the C1 posterior arch measuring <4 mm. In consideration of a high screw entry point on the C1 posterior arch, similar to the C1 posterior arch screw technique, we propose that this new technique can reduce venous plexus and C2 nerve root injury while providing effective biomechanical stability.

Long-Term Clinical and Radiologic Postoperative Outcomes After C1-C2 Pedicle Screw Techniques for Pediatric Atlantoaxial Rotatory Dislocation

BACKGROUND Although C1-C2 pedicle screw techniques have been extensively reported in pediatric series, reports on their use have examined only small series with short follow-up periods. The aim of this study was to report pediatric patients with atlantoaxial rotatory dislocation treated with these techniques with a minimum 5-year follow-up. METHODS Retrospective review was performed of 27 pediatric patients with atlantoaxial rotatory dislocation who underwent C1-C2 pedicle screw fixation between 2004 and 2012. Clinical and radiographic outcomes were collected and compared with a control group. RESULTS Follow-up period was 60-142 months (mean 84 months). Torticollis was completely corrected postoperatively in all but 1 patient. All patients experienced significant pain relief and improvement in range of motion, and 6 patients with neurologic deficits experienced significant improvement postoperatively. Both atlantodental interval and space available for the cord were significantly improved compared with preoperative values. At final follow-up, curvature was lordotic in 20 cases and straight in 7 cases. Compared with the control group, range of motion of the patient group was not significantly different in any direction except in flexion and rotation. Mean anteroposterior diameters of the spinal canal at C1 and C2 levels were not significantly different from the control group. CONCLUSIONS C1-C2 pedicle screw techniques are safe and effective for treatment of atlantoaxial rotatory dislocation and result in no obvious limitation on growth in older children.

Comparisons of Safety and Clinical Outcomes Between Multiple-level and Single-level Cervical Disk Replacement for Cervical Spondylosis: A Systematic Review and Meta-analysis.

Study Design:This is a systematic review and meta-analysis. Objective:The aim of this study was to evaluate the efficacy and safety of multiple-level cervical disk replacement (CDR) over single-level CDR for the treatment of cervical spondylosis. Summary of Background Data:Some authors advocate for the multiple-level CDR instead of anterior decompression and fusion in cervical multiple-level spondylosis. However, whether the efficacy and safety of multi-level CDR are as favorable as that of single-level CDR remains controversial. Methods:MEDLINE, EMBASE, and Cochrane library databases were searched up to November 2015 for controlled studies that compared the clinical outcomes of single-level and multiple-level CDR for the treatment of cervical spondylosis. The following outcomes were extracted and analyzed: prevalence of heterotopic ossification and reoperation, preoperative and postoperative Neck Disability Index scores, preoperative and postoperative Visual Analog Scale scores, and success rate using the Odom grading system. Results:Ten studies involving 1402 patients were included: including 3 randomized controlled trials, 5 prospective studies, and 3 retrospective studies. No significant differences between single-level and multiple-level groups were found in terms of the prevalence of heterotopic ossification and reoperation rate, Neck Disability Index score, Visual Analog Scale score, and success rate using the Odom grading system. Conclusions:On the basis of this meta-analysis, clinical outcomes of multiple-level CDR are similar to those of single-level CDR for cervical spondylosis, which suggests the multiple-level CDR is as effective and safe as the single-level CDR. Nonetheless, more well-designed studies are needed for further evaluation.

Long-Term Influence of C 1 -C 2 Pedicle Screw Fixation on Occipitoatlantal Angle and Subaxial Cervical Spine in the Pediatric Population

Objective: The goal of this study was to evaluate the impact of C₁-C₂ pedicle screw fixation on the occipitoatlantal angle and subaxial cervical spine for a pediatric population, and the clinical efficacy and adjacent-segment degeneration after C₁-C₂ pedicle screw fixation with a minimum of 2 years of follow-up. Methods: Twenty-two pediatric patients with atlantoaxial dislocation who were enrolled in this study underwent atlantoaxial pedicle screw fixation. The correlation between C₀-C₁, C₂-C₇, and C₁-C₂ pre- and postoperative sagittal angles was assessed using plain radiographs, and adjacent-segment degeneration (ASD) and JOA scores (Japanese Orthopaedic Association scores) were evaluated after atlantoaxial pedicle screw fixation. Results: The C₁-C₂ angle increased from 16.1 ± 13.37 to 28.1 ± 5.1° (p < 0.01). The pre- and postoperative C₁-C₂ angles were negatively correlated with the pre- and postoperative C₀-C₁ and C₂-C₇ angles, respectively. In accordance with the optimal atlantoaxial fusion angle (25-30°) obtained from the literature, postoperative JOA scores were greater in the groups with angles of more than 30° and less than 25°, although the difference in ASD was not statistically significant. Postoperative JOA scores were not relevant to the postoperative C₁-C₂ angle; however, there was a positive correlation between JOA improvement rate and the change of the C₁-C₂ angle postoperatively. Conclusion: Atlantoaxial pedicle screw fixation can be used easily to reduce atlantoaxial dislocation in the pediatric population; however, outside the range of the optimal atlantoaxial fusion angle it can change the occipitoatlantal angle and subaxial alignment, which induces ASD and influences the clinical efficacy. It is necessary to achieve an optimal atlantoaxial angle when using atlantoaxial pedicle screw fixation.

Atlantoaxial dislocation and os odontoideum in two identical twins: perspectives on etiology

PurposeThere are two theories about the origin of os odontoideum: traumatic or congenital. However, most studies favor the hypothesis of traumatic theory. To emphasize the congenital theory, we report a pair of identical twins both with atlantoaxial dislocation and os odontoideum, which is believed to be a congenital defect.MethodsWe present two 14-year-old identical twins with atlantoaxial dislocation and os odontoideum. Neither of the twins had history of trauma in head nor cervical spine. We reviewed and compared the cervical radiographs of the identical twins. Posterior atlantoaxial reduction, pedicle screw fixation and atlantoaxial fusion were performed for the two twins.ResultsRadiological examination showed the identical twins had typical atlantoaxial dislocation and os odontoideum. The twins had high similarity in the appearance of atlantoaxial dislocation and os odontoideum. The etiology of the os odontoideum in the twins is believed to be congenital. Both the twins had improvement in neurological function after surgery.ConclusionAlthough a great number of cases with os odontoideum have been reported to be traumatic, there are some cases believed to be congenital.