BACKGROUND:From the point of view of human anatomy, the load of the spine is more. When the body moves, the range of activities, and activity are relatively large. After screws were implanted in the spine, if biomechanical properties and stability are not up to the standard, it easily leads to lack of grip force of screw and screw loosening so as to increase the incidence of complications after treatment.
OBJECTIVE:To compare biomechanical properties and stability of the spine after insertion of pedicle screw and cervical vertebral screw into the spine.
METHODS:100 vertebrae under human cervical spine specimens were analyzed and randomly divided into cervical vertebral screw fixation group and pedicle screw fixation group. Cervical vertebral screws and pedicle screws were implanted in lower cervical spine specimens. Electro Force 3510 material testing machine was used to test axial pul-out force, axial pul-out strength after the fatigue loading, and fixed stability. The biomechanical properties and stability were compared after two kinds of screws were implanted in the spine.
RESULTS AND CONCLUSION:(1) Instantaneous pul out force and immediate pul out stiffness were significantly higher in the pedicle screw fixation group than in the cervical vertebral screw fixation group (P<0.05). (2) Fatigue pul-out strength and fatigue pul-out stiffness did not have significant differences in both groups, but statistical analysis showed significant differences (P<0.05). Fatigue pul-out strength and fatigue pul-out stiffness were significantly higher in the pedicle screw fixation group than in the cervical vertebral screw fixation group. (3) These results suggested that pedicle screw fixation after implantation in the spine provides sufficient fixation stability, has better fatigue resistance, elevates instantaneous pul-out force and fatigue pul-out strength, and presents strong stability.

BACKGROUND:Currently, surgical implant fixation is mainly applied for spinal tuberculosis. How to choose implant materials, however, is stil under discussion.OBJECTIVE:To compare the biocompatibility and mechanical properties of titanium al oy and stainless steel for rabbit spinal tuberculosis. METHODS:Thirty rabbits were chosen to prepare spinal tuberculosis models. Then, the rabbits were equivalently randomized into two groups, which underwent implant fixation with stainless steel or titanium al oy, respectively. At 30 days after implantation, biocompatibility and biomechanical properties of the two materials in the repaired region of spine were observed and detected, respectively. RESULTS AND CONCLUSION:In view of the biocompatibility, infection and immunological rejection could not been found in the titanium al oy group;in contrast, infection appeared in three rabbits of the stainless steel group. Flexion, extension and lateral bending displacements under the spinal loading in the titanium al oy group were significantly less than those in the stainless steel group (P<0.05);axial pul-out strength in the titanium al oy group was significantly higher than that in the stainless steel group (P<0.05);flexion, extension, lateral bending and axial compression in the titanium al oy group were significantly greater than those in the stainless steel group (P<0.05). In conclusion, titanium al oy material has good biocompatibility that can be used to restore and maintain the spinal stability.

ObjectiveTo analyze and summarize the feasibility and characteristics of the posterior spinal canal reduction and fixation in treating mid-upper thoracic spine facture.MethodsA retrospective study was made on 17 patients with mid-upper thoracic spine facture to record the complication, compare the functions of the patients with complete and incomplete spinal cord injuries before and after surgery and examine the iatrogenic injury in patients without spinal cord injuries.ResultsNo complication happened after surgery.Incomplete injury was found in six patients, whose ASIA scales were found to be increased for 1-3 levels during the follow-up.While the complete injury was found in eight patients,whose ASIA scale remained unchanged during the follow-up.The sensory scores of both the incomplete injury group and complete injury group were processed with variance analysis and the results showed a significant difference between pre-operation and post-operation (F = 476.47, P = 0.000).The mean value between complete injury group and incomplete group was with high statistical difference (F = 31.46, P =0.000).The variance analysis of the motor scores showed a significant difference between before and after operation (F=46.75, P =0.000) and the mean value between complete and incomplete injury groups was with statistical difference (F = 158.59, P = 0.000).There were three patients with normal spinal cord function, with no decrease of ASIA scale or no change of the sensory and motor scores.ConclusionsFor patients with mid-upper thoracic spine fracture, posterior spinal surgery is conducive to the recovery of spinal function, for it can safely and effectively avoid worsening the thoracic and other combined injuries and release spinal pressure including the pressure in front part of the spinal cannal.

Objective To observe the feasibility of posterior internal fixation with pedicle screw rod system for upper cervical vertebra injury. Methods 16 patients with upper cervical vertebra injury accepted posterior pedicle screw system internal fixation were reviewed. Results Venous plexus behind C2 damaged in operation in a case, who needed a microscope for hemostasis. No complication, such as neurological symptoms worse, cerebrospinal fluid leakage, hematoma and infection of incision happened post operation. The neurological symptoms improved 81.8% in all the 7 cases who complained before operation. No complication was found in the follow-up 3 to 18 months after discharge. Their activities of upper cervical was basically unaffected. Conclusion Posterior internal fixation with pedicle screw rod system can provide stable support for patients with upper cervical injury.

Objective:To investigate the impact of recombinant human epidermal growth factor (rh-EGF) on the epithelial recovery and the tear film stability after trans-epithelial corneal collagen crosslinking in patients with progressive keratoconus.Methods:A randomized controlled clinical trail was designed.Consecutive 66 patients (37 males and 29 females) with an average age of (21.27±3.80) years old diagnosed with primary progressive keratoconus and hospitalized in Xiamen Eye Center Affiliated to Xiamen University from October, 2016 to January, 2017 were enrolled and treated with unilateral enhanced transepithelial corneal crosslinking surgery by iontophoresis, and the patients were randomly divided into control group and experimental group according to random number table method, with 33 patients 33 eyes in each group.The eyes in the control group were treated with carboxy-methylcellulose sodium lubricant eye drops and the eyes in the experimental group were treated with rh-EGF eye drops.The ocular surface disease index (OSDI) questionare, slit lamp examination, Schirmer Ⅰ test, corneal fluorescein sodium staining scoring, non-contact tonometry, uncorrected visual acuity, best corrected visual acuity, bulbar conjunctival congestion scoring, lacrimal sevretion test, non-invasive break-up time of tear film (NIBUT), as well as tear meniscus height analysis were performed before surgery, and on day 1, day 3, day 5, day 7, day 14 and day 28 after surgery.This study followed the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Xiamen Eye Center Affiliated to Xiamen University (No.2016-ME-003).Results:On day 7 after surgery, the OSDI values were increased in both groups than the preoperative value, while the value in the experimental group was significantly lower than that in the control group ( P<0.05). There were statistically significant differences in the overall corneal epithelial staining score values between the two groups at different time points ( Fgroup=16.701, P<0.01; Ftime=454.418, P<0.01). The corneal epithelial staining score in the experimental group on day 3 and day 5 after surgery were significantly lower than those in the control group (1.79±0.65 vs. 2.70±0.68; 0.91±0.46 vs. 1.55±0.51) (both at P<0.01). The conjunctival congestion score in the experimental group was significantly lower than that of the control group on day 3 and day 5 after surgery (both at P<0.05). There were statistically significant differences in the overall NIBUT values between the two groups at different time points ( Fgroup=13.084, P<0.01; Ftime=34.383, P<0.01). The NIBUT values were significantly decreased rapidly on day 7, day 14 and day 28 after surgery in both groups (all at P<0.01), but gradually recovered.The NIBUT of the experimental group on day 7 and day 14 after surgery were significantly higher than those of the control group ([8.18±2.26]seconds vs. [5.93±2.33]seconds; [9.49±1.95]seconds vs. [7.52±2.27]seconds) (both at P<0.01). No statistical differences were found in the tonometry value, visual acuity, value of Schirmer I test as well as tear meniscus height at any time point before or after surgery between the two groups (all at P>0.05). Conclusions:Recombinant human epidermal growth factor has positive effects in the patients received enhanced transepithelial corneal crosslinking surgery, presenting with promotion of epithelial healing, relief of post-operative discomfort, and the recovery of tear film stability.

Objective: To evaluate the clinical value of high-risk humam papillomavirus(HR-HPV) genotyping in diagnosis of cervical lesions. Methods: Between December 2012 and March 2015, a total of 4 095 women who were diagnosed as cervical inflammation-related disease were chosen to be evaluated in gynecological clinic at Taizhou Hospital of Zhejiang Province. All the women experienced HPV genotyping, analysis of the epidemiological characteristics of HPV types in Taizhou area and theresult of histopathologic diagnosis of HPV positive women. Logistic regression analysis was used to estimate the risk of HR-HPV genotyping in cervical lesion progression. Results: Overall, HPV52 was the most prevalent genotype, followed by HPV16, 58, 39 and 56. Among the women with cervical intraepithelial neoplasm (CIN), HPV16 was the most frequent type, followed by HPV52, 58, 33 and 31. Logistic regression analysis showed that a higher risk of CIN2+ for women infected with HPV16 or HPV33, the regression coefficients OR were 3.670(95%CI: 2.399-5.612, P<0.05) and 2.045(95%CI: 1.087-3.848, P<0.05), respectively. Logistic regression analysis showed that a higher risk of CIN2+ for NILM with positive HPV16, and the regression coefficients OR were 2.539(95%CI: 1.622-3.976, P=0.000); the ASCUS with positive HPV16 and 58 had higher risk of CIN2+ , the regression coefficients OR were 1.911(95%CI: 0.530-6.893) and 1.757(95%CI: 0.557-5.548), respectively. Conclusions HPV genotyping has important clinical value to detect precancerous cervical lesions, especially when cervical cytology is negative, in management of patiemts with atypical squamous cells of an undertermined significance(ASCUS) or low grade squamous intraepithelial lesion(LSIL).

AIM: To investigate the preoperative ocular symptoms and the characteristics of asymptomatic ocular surface abnormalities in hospitalized patients with primary pterygium.METHODS: Cross-sectional study. Hospitalized patients diagnosed with primary pterygium and scheduled to receive pterygium excision surgery at the Xiamen Eye Center of Xiamen University from August 2022 to October 2022 were enrolled. Ocular surface disease index questionnaire(OSDI), six examinations including non-invasive tear film break-up time, Schirmer I test, tear meniscus height, lid margin abnormality, meibomian gland dropout and tear film lipid layer thickness, and anterior segment optical coherence tomography(AS-OCT)were performed and statistically analyzed.RESULTS: A total of 178 cases(178 eyes), with a mean age of 54.39±10.75 years old, were recruited, including 75 males(42.1%)and 103 females(57.9%). The average values of ocular surface parameters in these patients included OSDI: 11.47±9.69, tear film break-up time: 7.10±3.86 s; tear meniscus height: 0.16±0.07 mm, Schirmer I test values: 14.39±7.29 mm/5 min, and pterygium thickness: 504.74±175.87 μm. Totally 161 eyes(90.4%)presented with abnormal lid margin, 44 eyes(24.7%)presented with meibomian gland dropout score ≥4, 52 eyes(29.2%)presented with low lipid layer thickness. In the 6 objective examinations, abnormalities in at least 4 of these tests were found in 85.4% of eyes. Pterygium morphology was classified into four grades: 10 eyes(5.6%)of grade Ⅰ, 93 eyes(52.2%)of grade Ⅱ, 60 eyes(33.7%)of grade Ⅲ, and 15 eyes(8.4%)of grade Ⅳ. In patients with a higher grade of pterygium, the tear film break-up time was lower, and the proportion of abnormal lid margin was also significantly higher(P<0.05). The patients were further divided into two subgroups, including 121 eyes(68.0%)with normal OSDI <13 in the normal group and 57 eyes(32.0%)with OSDI ≥13 in the abnormal group. No significant difference was found in the proportion of meibomian gland dysfunction between the two groups of patients(71.9% vs. 71.9%, P=0.872). In addition, there were differences in the number of abnormal objective examinations(4.11±0.85 vs. 4.91±0.99, P<0.001).CONCLUSIONS: Asymptomatic ocular surface abnormalities were present preoperatively in patients hospitalized for primary pterygium. A comparable high incidence of structural or functional meibomian gland dysfunction existed in pterygium patients with or without apparent ocular discomfort. More attention should be paid to the ocular surface abnormalities in those asymptomatic patients before primary pterygium surgery.