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.

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.

There is lack data concerning anterior cervical spine revision surgeries; even more data are missing concerning posterior cervical revision surgeries, to determine the feasibility, safety, and clinical efficacy of revision surgery for irreducible atlantoaxial dislocation (RS-IAAD). Patients with IAAD-FS underwent one-stage transoral release and posterior reduction. Their medical history was documented in detail. The JOA score system was used to evaluate each patient's neurological status pre and postoperatively, and serial MRI and radiographs were used to determine the status of the reduction and the autografts. 16 patients (average age, 36 years old) underwent successful surgery. There was no intraoperative or postoperative neurological deficit except in two cases that suffered transient neurological deficit that alleviated after conservative treatment. Solid bony union was seen at the end of 3 months after surgery in all patients. The mean follow-up period was 28.8 months (range 18-66 months). No pseudarthrosis was noted. Anterior transoral release and posterior instrumented fusion remain significant surgeries with the potential for serious complications, but in the current series there were no major complications.

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.

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.

Background To investigate the efficacy and safety of endoscopic transnasal anterior release and posterior reduction without odontoidectomy to treat irreducible atlantoaxial dislocation (IAAD). Methods A series of 9 patients with IAAD underwent endoscopic transnasal anterior release and posterior reduction without odontoidectomy. Etiology, instrumentation, fusion rate, and complications were documented. All patients were assessed clinically and radiologically for neurological recovery using the Japanese Orthopedic Association (JOA) score, atlantodontoid interval (ADI), and cervicomedullary angle (CMA). Results The mean age of the patients was 41.6 years, ranging from 14 to 60 years. Pathology showed os odontoideum in 3 patients, old traumatic dens fracture in 3 patients, occipitalization of C1 in 2 patients, and rheumatoid arthritis in 1 patient. Seven patients underwent C1–C2 pedicle screw fixations, and 2 patients required occipitocervical fixation. Eight cases resulted in complete reduction and 1 in partial reduction. Complications included one superficial infection related to the posterior approach. All patients were followed up for an average of 17 (range 13–32) months. Bony fusion was confirmed in all cases under radiologic assessment at 1 year postoperatively, and the bony fusion rate reached 100%. Moreover, no instrumental failure occurred during the entire follow-up period. The JOA score improved from 7.21 ± 1.62 to 12.28 ± 0.81 at the last follow-up. The ADI of 9 cases was 7.06 ± 0.85 mm preoperatively, which decreased to 2.26 ± 0.56 mm at the final follow-up. CMA improved from 103.80° ± 4.16° to 143.23° ± 7.47° postoperatively. Conclusion With transnasal approach and lack of odontoidectomy, this method could not only treat IAAD safely and effectively, but also reduce the possibility of many complications associated with the traditional transoral approach and odontoidectomy.

Objective: To determine the asymmetry in the paraspinal muscle before pregnancy and evaluate its association with pregnancy-associated lumbopelvic pain (LPP).Methods: This was a prospective case-control study conducted from January 2017 and December 2018. A total of 171 subjects (mean age AE SD, 27.4 AE 5.8 years) were finally divided into the LBP group, PGP group, and no LPP group. Each subject was asked to follow a standardized clinical imaging protocol before the pregnancy. The area of muscles (multifidus, erector spinae, and psoas muscles) on the axial slice at mid-disc of L 4 -L 5 and L 5 -S 1 were segmented and then the cross-sectional area (CSA) of a particular muscle was measured by outlining the innermost fascial border surrounding each muscle. The mean value of F-CSA's ratio to T-CSA (F/T CSA) was used to determine whether the bilateral paraspinal muscle was asymmetrical. Total muscle CSA (T-CSA) represents the sum of CSA of interested three muscles. The signal intensity can distinguish fat and muscle tissue in a different range. Based on this, functional CSA (F-CSA), represented by fat-free area, was evaluated quantitively by excluding the signal of the deposits of intramuscular fat. Total muscle CSA (T-CSA), functional CSA (F-CSA), and the ratio of F-CSA to T-CSA (F/T CSA) were measured unilaterally and compared between groups. Logistic regression was performed to determine the risk factors for pregnancy-associated LPP. The Pearson correlation coefficient was performed to test the relationship between asymmetry in F/T-CSA and pain rating.Results: A total of 124 subjects (72.5%) (28.5 AE 5.2 years) had LPP during pregnancy. Forty-eight (38.7%) individuals had low back pain (LBP) and 76 (61.3%) had pelvic girdle pain (PGP). Seventy-six women (44.4%) were determined to have asymmetry in paraspinal muscle according to the definition in this methods section. The duration of follow-up was 24 months postpartum. A total of 39 (31.5%) women unrecovered from LPP. F/T-CSA was significantly decreased for LBP in the PGP group than in the and control group (0.03 AE 0.02 vs 0.05 AE 0.03 vs 0.12 AE 0.05, P < 0.001). Meanwhile, significant differences were detected in both groups (all P < 0.001). In patients with LBP, the level of paraspinal asymmetry, represented by the difference in F/T-CSA, was positively correlated with pain scores (r = 0.52, P < 0.01). However, no statistically significant correlation between pain scores and paraspinal asymmetry was found in PGP (r = 0.42, P > 0.05). Asymmetry in the paraspinal muscle (adjusted OR = 1.5), LBP (adjusted OR = 1.6), LPP in a previous pregnancy (adjusted OR = 1.4), sick leave ≥90 days (adjusted OR = 1.2), and heavy labor (adjusted OR = 1.2) were risk factors for the unrecovered LPP during pregnancy.Conclusions: Asymmetrical muscular compositions could lead to abnormal biomechanics for the segmental motions.Lateral-directed physical training and stretching may help decrease the occurrence and severity of this condition.

Background:Continuous negative pressure drainage (CNPD) is widely used after lower lumbar internal fixation; however, it may cause tremendous blood loss and lead to postoperative hemorrhagic anemia. The present study explored the efficacy and safety of improved intermittent-clamped drainage (ICD) for lower lumbar internal fixation.Methods:This was a prospective study that included 156 patients with decompression of the spinal canal and internal fixation for the first time from January 2012 to December 2014. The patients were randomly divided into ICD group and CNPD group, and each group had 78 cases. A drainage tube was placed under the deep fascia in all patients within 10 min after the commencement of wound closure. The postoperative drainage amount at different time points, the hemoglobin level, and postoperative complications were recorded and compared between the two groups. Shapiro-Wilk test, independent samples t-test, and Mann-Whitney U-test were used in this study.Results:The drainage amount was significantly reduced in the ICD group, as compared with the CNPD group (Z = 10.74, P < 0.01). The mean total drainage amount (in ml) of the single-segment and two-segment procedures was significantly greater in the CNPD group than the ICD group (Z = 10.63 and 10.75, respectively; P < 0.01). For the adverse events, there was no significant difference in postoperative temperature, wound problem, and complications between the two groups.Conclusions:The present study showed a statistically significant reduction in postoperative drainage amount between ICD and CNPD groups, and ICD is an effective, convenient, and safe method for routine use in lower lumbar surgery. It is essential to focus on the effect of clamping drainage with long-segment surgical procedure and complex lumbar disease in the further investigation, as well as the effect of clamping on long-term functional outcomes.