Combined anterior and posterior approach in treatment of ankylosing spondylitis-associated cervical fractures: a systematic review and meta-analysis.

OBJECTIVE: Cervical fractures with ankylosing spondylitis (CAS) are a specific type of spinal fracture with poor stability, low healing rate, and high disability rate. Its treatment is mainly surgical, predominantly through the anterior approach, posterior approach, and the anterior-posterior approach. Although many clinical studies have been conducted on various surgical approaches, controversy still exists concerning the choice of these surgical approaches by surgeons. The authors present here a systematic evaluation and meta-analysis exploring the utility of the anterior-posterior approach versus the anterior approach and the posterior approach. METHODS: After a comprehensive literature search of PubMed, Cochrane, Web of Science, and Embase databases, 12 clinical studies were included in the final qualitative analysis and 8 in the final quantitative analysis. Of these studies, 11 conducted a comparison between the anterior-posterior approach and the anterior approach and posterior approaches, while one examined only the anterior-posterior approach. Where appropriate, statistical advantage ratios and 95% confidence intervals were calculated. RESULTS: The present meta-analysis of postoperative neurological improvement showed no statistical difference in the overall neurological improvement rate between the anterior-posterior approach and anterior approach (OR 1.70, 95% CI 0.61 to 4.75; p = 0.31). However, the mean change in postoperative neurological function was lower in patients who received the anterior approach than in those who received the anterior-posterior approach (MD 0.17, 95% CI -0.02 to 0.36; p = 0.08). There was an identical trend between the anterior-posterior approach and posterior approach, with no statistically significant difference in the overall rate of neurological improvement (OR 1.37, 95% CI 0.70 to 2.56; p = 0.38). Nevertheless, the mean change in neurological function was smaller in patients receiving the anterior-posterior approach compared with the posterior approach, but there was no statistically significant difference between the two (MD 0.17, 95% CI -0.02 to 0.36; p = 0.08). CONCLUSIONS: The results of this review and meta-analysis suggest that the benefits of the anterior-posterior approach are different from those of the anterior and posterior approaches in the treatment of ankylosing spondylitis-related cervical fractures. In a word, there is no significant difference between the cervical surgical approach and the neurological functional improvement. Therefore, surgeons should pay more attention to the type of cervical fracture, the displacement degree of cervical fracture, the spinal cord injury, the balance of cervical spine and other aspects to comprehensively consider the selection of appropriate surgical methods.

[Estrogen reduced myocardial damage by regulating Gαs-cAMP pathway in isoprenaline injured rats].

The aim of the present study is to explore the mechanism of estrogen on regulating cardiac function disorder by adjusting the stimulating adenylate cyclase G α protein (Gαs)-cycle adenosine monophosphate (cAMP) signal pathway. Adult female rats were randomly divided into five groups: sham group, ovariectomized group (OVX), OVX and 17ß-estradiol given group (OVX+E2), OVX and isoprenaline injected group (OVX+ISO), OVX and 17ß-estradiol, isoprenaline injected group (OVX+E2+ISO). Rats were ovariectomized, and two weeks later, OVX+E2group was injected with E2, OVX+ISO group was injected with ISO, OVX+E2+ISO group was injected with E2and ISO. Another four weeks later, the hemodynamic parameters were monitored by carotid artery intubation: left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), maximal differentials of left ventricular developed pressure (+dp/dt(max)), and minimal differentials of left ventricular developed pressure (-dp/dt(max)). Brain natriuretic peptide (BNP) and cAMP concentration in plasma were determined; Gα(s) protein expression in myocardium was determined. The results showed that the hemodynamic parameters, the concentration of BNP and cAMP in plasma had no significant changes after ovariectomy compared with sham group. But after isoprenaline injection in ovariectomized rats, LVSP and +dp/dt(max) declined (P < 0.01), LVEDP and -dp/dt(max) elevated (P < 0.01); plasma BNP concentration increased (P < 0.01); plasma cAMP concentration decreased (P < 0.01), compared with OVX group. Further estrogen supplements improved the heart function treated by isoprenaline: LVSP and +dp/dt(max) elevated (P < 0.01), LVEDP and -dp/dtmax declined (P < 0.05, P < 0.01); the plasma BNP concentration decreased (P < 0.01); the plasma cAMP concentration increased (P < 0.01). Estrogen had no significant influence on Gαs protein expression. The results suggest that estrogen can alleviate myocardial injury and regulate cardiac function disorder by increasing cAMP level, finally improved the excessive suppression of myocardium.