Is it Suitable to Fix the Occipito-C2 Angle and the Posterior Occipitocervical Angle in a Normal Range During Occipitocervical Fusion?

STUDY DESIGN: This is a retrospective study. OBJECTIVES: The objective of this study was (1) to measure the occipito-C2 angle (OC2A) and the posterior occipitocervical angle (POCA) in a normal population, and (2) to observe the effects of OC2A and POCA selection on postoperative clinical efficacy and lower cervical curvature after occipitocervical fusion (OCF) in patients with basilar invagination (BI) and atlantoaxial fracture and dislocation (AAFD). SUMMARY OF BACKGROUND DATA: OC2A has received special attention with respect to the clinical efficacy during OCF. However, none of studies have focused on the relationship between OC2A and POCA and have assessed their impact on clinical outcomes in patients with different occipiocervical diseases. MATERIALS AND METHODS: One hundred fifty healthy subjects without any cervical disease (healthy group) were randomly selected based on sex and age. Three spine surgeons measured the OC2A and POCA in the healthy group and averaged the values. Forty-two patients with BI (BI group) and 32 patients with AAFD (AAFD group) who underwent OCF between January 2012 and January 2017 were reviewed. OC2A, POCA, and cervical spinal angle (CSA) were measured preoperatively, postoperatively immediately after surgery and ambulation, and at the final follow-up visit. The preoperative and final follow-up visual analog scale (VAS), Japanese Orthopaedic Association score (JOA), neck disability index (NDI), and the change of CSA from postoperatively immediately after surgery and ambulation to the final follow-up (dCSA) were recorded. RESULTS: The values of OC2A and POCA were 14.5±3.7 and 108.2±8.1 degrees in the healthy group, respectively, and the respective 95% confidence intervals were 7.2-21.8 and 92.3-124.0 degrees as the normal range. There was a negative correlation between OC2A and POCA (r=-0.386, P<0.001). The preoperative value of OC2A (5.6±4.3 degrees) in BI group was smaller than that in the healthy group (P<0.05); however, the preoperative value of POCA (123.0±10.4 degrees) in the BI group was larger than that in the healthy group (P<0.05). There was no significantly different of OC2A and POCA between the healthy group and the AAFD group before the operation (P>0.05). The preoperative value of CSA (25.7±9.5 degrees) in the BI group was larger than that in the AAFD group (16.5±5.1 degrees) (P<0.05). In the BI group, 26 patients had ideal OC2A and POCA (both within 95% confidence interval of the healthy group) postoperatively immediately after surgery and ambulation as a subgroup of the ideal angle group. In the remaining patients with BI (nonideal angle group), VAS, JOA, and NDI at the final follow-up were significantly better than those in the ideal angle group (P<0.05). The ideal angle group showed statistically greater dCSA than the nonideal angle group of the BI group (P<0.05). On the contrary, in the AAFD group, the NDI in the ideal angle group (20 patients) was better than that in the nonideal angle group at the final follow-up, and the ideal angle group had a smaller dCSA compared with the nonideal angle group (P<0.05). CONCLUSIONS: The biomechanical balance of occipitocervical region in patients with occipitocervical diseases with different pathogenesis is different. On the basis of the different types of occipitocervical diseases, an appropriate range of OC2A and POCA should be selected by the surgeon during OCF, which can further improve the clinical efficacy and reduce the loss of the lower cervical curvature after surgery.

Importance of the Occipitoaxial Angle and Posterior Occipitocervical Angle in Occipitocervical Fusion.

OBJECTIVE: To observe the effects of occipitoaxial angle (O-C2 angle, OC2A) and posterior occipitocervical angle (POCA) selection on postoperative clinical efficacy and lower cervical curvature in patients with acute acquired atlantoaxial dislocation after occipitocervical fusion (OCF). METHODS: A total of 150 healthy subjects without cervical disease (healthy group) were randomly selected based on gender and age. Three spine surgeons measured the OC2A and POCA of the healthy group and averaged the values. A total of 30 patients with an average age of 51.0 years (range, 18-70 years; 16 male and 14 female) with trauma or rheumatoid arthritis (disease group) who underwent occipitocervical fusion (OCF) for atlantoaxial dislocation between January 2012 and June 2016 were reviewed. OC2A, POCA, and cervical spinal angle (CSA) were measured postoperative/soon after surgery and ambulation, and at the final follow-up visit. The preoperative and final follow-up visual analog scale (VAS), Japanese orthopedics association score (JOA), neck disability index (NDI), and dCSA (change of CSA from postoperative/soon after surgery and ambulation to final follow-up) were recorded. RESULTS: The values of OC2A and POCA in 150 healthy subjects were 14.5° ± 3.7° and 108.2° ± 8.1°, respectively, and the 95% confidence interval (CI) were 7.2°-21.8° and 92.3°-124.0°, respectively. There was a negative correlation between OC2A and POCA (r = -0.386, P < 0.001). There were 18 patients (group one) of ideal OC2A and POCA (both within 95% CI of the healthy group) postoperative/soon after surgery and ambulation with a mean follow-up time of 26.3 ± 20.9 months in disease group. The remaining patients (group two) with a mean follow-up time of 31.3 ± 21.3 months. There was no statistically significant difference in the baseline data as well as pre-operative outcomes, including VAS score, JOA score, and NDI between the two groups. Likewise, the post-operative outcomes in final follow-up, including VAS and JOA score, had no distinct difference in the two groups. However, NDI (11.0 ± 2.9) in group two at the final follow-up was significantly higher than that in group one (7.0 ± 2.3) (P < 0.001). And group two showed statistically greater dCSA (5.9 ± 7.5°) than group one (-2.3° ± 6.2°) (P = 0.003). CONCLUSIONS: The negative correlation between OC2A and POCA plays an important role in maintaining the biodynamic balance of the occipital-cervical region. OC2A and POCA should be controlled of a normal population in patients with acute acquired atlantoaxial dislocation during OCF, which can further improve the clinical efficacy and prevent loss of lower cervical curvature after surgery.

Evaluation of surgical risk and prognosis between thyroid nodules of size <1 and ≥1 cm.

BACKGROUND: The objective of this study was to evaluate the surgical risk and prognosis between thyroid nodules of size <1 and ≥1 cm and to explore whether it is reasonable generally to ignore the diagnosis and treatment of thyroid nodules and thyroid carcinoma <1 cm in wide areas of China. METHODS: A retrospective observational study included all first-time thyroid surgery patients between January 2005 and December 2016 of the First Affiliated Hospital of Harbin Medical University. All patients were divided into two groups (group A: <1 cm, group B: ≥1 cm) according to the maximum diameter of the nodules and demographics, surgery procedure, pathology, postoperative complications, morbidity, and mortality were analyzed. RESULTS: A total of 6,317 patients were reviewed and 3,424 (54.20%) of them were malignant; 2,128 patients in group A and 4,189 in group B. Patients in group A had better pathological diagnosis, inferior extent of lymph node metastasis, less surgical complexity, fewer postoperative complications, and longer disease-free survival (DFS). CONCLUSIONS: Thyroid operations were safer and involved fewer postoperative complications when thyroid nodules were <1 cm and patients who were diagnosed with malignant thyroid disease had superior prognoses. Underdeveloped regions of China should diagnose and treat thyroid nodules <1 cm early.

[Imaging measurement and clinical significance of occipitocervical angle in healthy people at different ages].

OBJECTIVE: To measure imaging data of occipitocervical angle in healthy people at different ages by X-ray. METHODS: One hundred and fifty asymptomatic volunteers(75 males and 75 females) aged from 20 and 70 years old with an average of(44.83±13.88) years old were divided into 5 groups according to different ages(20 to 29 years old, 30 to 39 years old, 40 to 49 years old, 50 to 59 years old and 60 to 70 years old), and 30 people in each group. All people underwent lateral radiography of neck on neutral position. McGregor line (the lowest connection line between upper margin of hard palate and occipital scales of plating), occipitocervical angle(OCA) formed by edge of C2 vertebral body, takami's occipitocervical angle formed between connection line of posterior marginal of C2 vertebral body and parallel lines of hard palate were collected. The data were performed statistical analysis according to gender and different ages, and analyzed correlation between OCA and TOCA. RESULTS: OCA of 75 males at different ages were (14.71±3.09)° and(14.22±4.27)° in 75 females. TOCA of 75 males at different ages were (90.50±4.63)° and (90.57±6.67) ° in 75 females. There were no statistical difference in OCA and TOCA in people at different ages(P<0.05). There were no significant meaning among 5 groups at different ages in OCA and TOCA(P>0.05). The relation analysis results showed positive correlation between OCA and TOCA(r=0.454, P<0.01). CONCLUSIONS: The paper provided normal values for occipitocervical angle in population of southwestern China between 20 and 70 years old, and results may be useful for posterior occipitocervical fixation and fusion.

Revision surgery after rod breakage in a patient with occipitocervical fusion: A case report.

RATIONALE: Rod breakage after occipitocervical fusion (OCF) has never been described in a patient who has undergone surgery for basilar invagination (BI) and atlantoaxial dislocation (AAD). Here, we present an unusual but significant case of revision surgery to correct this complication. PATIENT CONCERNS: A 32-year-old female presented with neck pain, unstable leg motion in walking, and also BI with AAD. Her first surgery was planned to correct these conditions and for fusion at the occipital junction (C3-4) using a screw-rod system. At the 31-month follow-up after her first operation, the patient complained of severe neck pain and limitation of motion, suggesting rod breakage. DIAGNOSES: Rod breakage after occipitocervical fusion for BI and AAD. INTERVENTIONS: The patient underwent reoperation for replacement of the broken rods, adjustment of the occipitocervical angle, maintenance of the bone graft bed, and fusion. OUTCOMES: At follow-up, the hardware was found to be in good condition, with no significant loss of cervical lordosis. At the 37-month follow-up after her second operation, the patient was doing better and continuing to recover. LESSONS: We concluded that nonideal choice of occipitocervical angle may play an important role in rod breakage; however, an inadequate bone graft and poor postoperative fusion may also contribute to implant failure.

[Analysis of clinical effects of absorbable hemostatic fluid gelatin and absorbable gelatin sponge on the hemostasis during operation of unilateral open-door cervical expansive laminoplasty].

OBJECTIVE: To compare the hemostatic effect between absorbable hemostatic fluid gelatin (HFG) and absorbable gelatin sponge(GS) during operation of unilateral open-door cervical expansive laminoplasty. METHODS: The clinical data of 83 patients underwent unilateral open-door cervical expansive laminoplasty from February 2014 to May 2016 were retrospectively analyzed. According to the used hemostatic materials, patients were divided into two groups. In HFG group, there were 30 males and 11 females, ranging in age from 29 to 81 years, with an average of(55.6±11.6)years; 14 cases were simple cervical spinal stenosis, 9 were cervical spinal stenosis and ossification of posterior longitudinal ligament, and 18 were cervical spinal stenosis complicated with multiple cervical disc herniation. And in GS group, there were 32 males and 10 females, ranging in age from 36 to 78 years, with an average of (55.4±11.1) years; 12 cases were simple cervical spinal stenosis, 10 were cervical spinal stenosis complicated with ossification of posterior longitudinal ligament, and 20 were cervical spinal stenosis complicated with multiple cervical disc herniation. There was no significant difference in the age, gender, and disease categories of patients between two groups (P>0.05). The operative time, intraoperative bleeding, postoperative drainage, and postoperative complications were compared between two groups. RESULTS: The average operative time, intraoperative bleeding, and postoperative drainage in HFG group were(137.2±30.0) min, (156.1±74.6) ml, and (212.1±67.6) ml, respectively; and in GS group were (154.8±33.5) min, (242.9±120.7) ml, and(303.3±115.5) ml, respectively. There were significantly differences in above items between two groups(P<0.05). No acute heamatoma or related complications was found postoperatively. CONCLUSIONS: Compared with GS, HFG can obviously decrease operative time, intraoperative bleeding, and postoperative drainage. It is a safe and effective hemostatic material for the operation of unilateral open-door cervical expansive laminoplasty.

Distinct patterns of simple sequence repeats and GC distribution in intragenic and intergenic regions of primate genomes.

As the first systematic examination of simple sequence repeats (SSRs) and guanine-cytosine (GC) distribution in intragenic and intergenic regions of ten primates, our study showed that SSRs and GC displayed nonrandom distribution for both intragenic and intergenic regions, suggesting that they have potential roles in transcriptional or translational regulation. Our results suggest that the majority of SSRs are distributed in non-coding regions, such as the introns, TEs, and intergenic regions. In these primates, trinucleotide perfect (P) SSRs were the most abundant repeats type in the 5'UTRs and CDSs, whereas, mononucleotide P-SSRs were the most in the intron, 3'UTRs, TEs, and intergenic regions. The GC-contents varied greatly among different intragenic and intergenic regions: 5'UTRs > CDSs > 3'UTRs > TEs > introns > intergenic regions, and high GC-content was frequently distributed in exon-rich regions. Our results also showed that in the same intragenic and intergenic regions, the distribution of GC-contents were great similarity in the different primates. Tri- and hexanucleotide P-SSRs had the most GC-contents in the 5'UTRs and CDSs, whereas mononucleotide P-SSRs had the least GC-contents in the six genomic regions of these primates. The most frequent motifs for different length varied obviously with the different genomic regions.

Guanine-decorated graphene nanostructures for sensitive monitoring of neuron-specific enolase based on an enzyme-free electrocatalytic reaction.

A new and enzyme-free electrochemical immunoassay protocol was developed for the sensitive electronic monitoring of neuron-specific enolase (NSE) on a monoclonal mouse anti-human NSE antibody (mAb)-modified glassy carbon electrode, using guanine-decorated graphene nanostructures (GGN) as nanotags. To construct such an enzyme-free immunoassay format, guanine and polyclonal rabbit anti-human NSE antibody (pAb) were co-immobilized on the graphene nanostructures through the carbodiimide coupling. Based on a sandwich-type immunoassay mode, the assay was carried out in 0.1 M pH 7.4 PBS containing 5 µM Ru(bpy)3(2+) through the catalytic oxidation of Ru(bpy)3(2+) toward the guanine on the GGN. The presence of graphene nanostructures increased the immobilized amount of guanine, thus amplifying a detectable electronic signal. The covalent conjugation of guanine and pAb on the GGN resulted in a good repeatability and intermediate reproducibility down to 9.5%. Under optimal conditions, the dynamic concentration range of the developed immunoassay spanned from 0.005 to 80 ng mL(-1) NSE with a detection limit of 1.0 pg mL(-1) at the 3S(blank) level. In addition, the methodology was evaluated by assaying the spiking serum samples, and the relative standard deviation (RSD) between the electrochemical immunoassay and a commercialized enzyme-linked immunosorbent assay (ELISA) were 2.8-7.0%.

Selection of suitable reference genes for normalization of quantitative real-time PCR in cartilage tissue injury and repair in rabbits.

When studying the altered expression of genes associated with cartilage regeneration by quantitative real-time RT-PCR (RT-qPCR), reference genes with highly stable expression during different stages of chondrocyte developmental are necessary to normalize gene expression accurately. Until now, no reports evaluating expression changes of commonly used reference genes in rabbit articular cartilage have been published. In this study, defects were made in rabbit articular cartilage, with or without insulin-like growth factor 1 (IGF-1) treatment, to create different chondrocyte living environments. The stability and intensity of the expressions of the candidate reference genes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 18S Ribosomal RNA (18S rRNA), cyclophilin (CYP), hypoxanthine phosphoribosyl transferase (HPRT1), and beta-2-microglobulin (B2M) were evaluated. The data were analyzed by geNorm and NormFinder. B2M and 18S rRNA were identified to be suitable reference genes for rabbit cartilage tissues.