Objective: To analyze the mediating effects of loneliness and depressive symptoms on family functioning and life satisfaction among rural elderly patients with chronic diseases, so as to provide the basis for improving the life satisfaction of this population. Methods: Rural elderly patients with chronic diseases aged ≥60 years in Qiannan Buyi and Miao Autonomous Prefecture, Guizhou Province were selected using a multi-stage stratified random cluster sampling method from June to September 2022. Basic information such as gender, age, and chronic diseases were collected. Family function, life satisfaction, loneliness and depressive symptoms were evaluated using Family Care Index Scale, the Satisfaction with Life Scale, the b-item Revised VCLA Loneliness Sale and the 15-item Geriatric Depression Scale, respectively. The structural equation model was constructed using Amos software to analyze the mediating effects of loneliness and depressive symptoms on the relationship between family function and life satisfaction. The Bootstrap method was employed to test the mediating effects. Results: A total of 1 145 rural elderly patients with chronic diseases were recruited, including 517 males (45.15%) and 628 females (54.85%). Among the participants, 657 individuals (57.38%) were aged 60-<71 years, and 540 individuals (47.16%) had three or more chronic diseases. The scores for family function, life satisfaction, loneliness, and depressive symptoms were (3.90±1.18), (18.88±5.25), (12.88±2.99), and (6.65±2.26), respectively. Mediating effect analysis showed that family function had a direct positive effect on life satisfaction (β=0.179, 95%CI: 0.126-0.231). It also indirectly positively influenced the life satisfaction of rural elderly patients with chronic diseases through the independent mediating effect of depressive symptoms (β=0.035, 95%CI: 0.021-0.054) and the chained mediating effect of loneliness and depressive symptoms (β=0.021, 95%CI: 0.013-0.030). The mediating effect of depressive symptoms accounted for 14.89% of the total effect, while the chained mediating effect of loneliness and depressive symptoms accounted for 8.94% of the total effect. Conclusion Good family function can directly enhance the life satisfaction of rural elderly patients with chronic diseases and can also indirectly improve their life satisfaction by reducing loneliness and depressive symptoms.

OBJECTIVE: To analyze the effectiveness of three internal fixation methods, namely hollow screw combined with Kirschner wire tension band, hollow screw combined with anchor nail, and modified 1/3 tubular steel plate, in the treatment of avulsion fracture of tibial tubercle (AFTT) in adolescents. METHODS: Between January 2018 and September 2023, 19 adolescent AFTT patients who met the selection criteria were admitted. According to different internal fixation methods, patients were divided into group A (8 cases, hollow screw combined with Kirschner wire tension band), group B (6 cases, hollow screw combined with anchor nail), and group C (5 cases, modified 1/3 tubular steel plate). There was no significant difference in the baseline data of age, gender, side, cause of injury, Ogden classification, and time from injury to operation among the three groups ( P>0.05). The range of motion (ROM), weight-bearing time, normal activity time of knee joint, and the hospital for special surgery (HSS) score at last follow-up were recorded and compared among the three groups. Recorded whether the fracture was displaced, whether the fracture line was blurred at 1 month after operation, whether there was epiphyseal dysplasia, and whether there was incision infection and other complications. RESULTS: There was no significant difference in hospital stay between the groups ( P>0.05). All patients were followed up 10-24 months, with an average of 14.3 months; there was no significant difference between the groups ( P>0.05). All the incisions healed well without soft tissue irritation or fracture nonunion, and no limb shortening deformity or epiphyseal dysplasia was found during follow-up. At 1 month after operation, the knee joint ROM and hospitalization expenses in group A were better than those in groups B and C, the fracture healing time, knee joint weight-bearing time, and normal activity time of knee joint were better than those in group C, and the hospitalization expenses in group C were better than those in group B, with significant differences ( P<0.05); there was no significant difference in the other indicators between the groups ( P>0.05). In group A, the fracture line was blurred 1 month postoperatively, the fracture ends were in close contact, and there was no fracture displacement; in groups B and C, the fracture line was clear in 2 cases, and 1 case in group C had slight fracture displacement; except for 1 case in group B, there was no fracture split in the other two groups. There was no significant difference in the incidences of blur of fracture line, fracture displacement, and intraoperative bone split between the groups at 1 month after operation ( P>0.05). At last follow-up, the HSS scores of knee joints in the three groups were excellent and good, and there was no significant difference between the groups ( P>0.05). CONCLUSION Hollow screw combined with Kirschner wire tension band technique is effective in treating adolescent AFTT, which has the advantages of stabilizing fracture, accelerating fracture healing and rehabilitation, early feasible knee joint functional exercise, and reducing hospitalization expenses.
Humans ; Tibial Fractures/surgery* ; Adolescent ; Male ; Fracture Fixation, Internal/instrumentation* ; Female ; Fractures, Avulsion/surgery* ; Bone Wires ; Bone Screws ; Bone Plates ; Treatment Outcome ; Range of Motion, Articular ; Bone Nails ; Weight-Bearing ; Fracture Healing

OBJECTIVE: To explore effectiveness of intermediate screw assisted reduction and fixation technique in the treatment of Schatzker type Ⅴ and Ⅵ tibial plateau fractures. METHODS: A clinical data of 22 patients with Schatzker type Ⅴ and Ⅵ tibial plateau fractures, who were admitted between June 2022 and December 2023 and met the selection criteria, was retrospectively analyzed. During operation, the intermediate screw assisted reduction and fixation technique was used. There were 14 males and 8 females with an average age of 46.3 years (range, 17-65 years). The fractures were caused by traffic accident in 13 cases, by falls in 5 cases, and by falling from height in 4 cases. According to Schatzker classification criteria, 9 cases were type Ⅴ and 13 cases were type Ⅵ. The interval between injury and operation was 5-12 days (mean, 7.9 days). The operation time, intraoperative fluoroscopy times, and length of hospital stay were recorded. The range of motion of knee joint and Hospital for Special Surgery (HSS) score were recorded at last follow-up. X-ray films were taken to review the fracture healing. Rasmussen score, tibial plateau varus angle (TPVA), and posterior tibial slope (PTS) were estimated before operation, at immediate after operation, and at last follow-up in order to evaluate the fracture reduction effect and postoperative outcome. RESULTS: The operation time was 85-140 minutes (mean, 103.9 minutes). Intraoperative fluoroscopy was performed 7-15 times (mean, 10.1 times). All incisions healed by first intention after operation, and no complication such as nerve or blood vessel injury occurred. The length of hospital stay ranged from 8 to 17 days (mean, 12.4 days). All patients were followed up 10-22 months (mean, 14.8 months). At last follow-up, the range of motion of knee joint was 110°-140° (mean, 125°). HSS score was rated as excellent in 16 cases, good in 5 cases, and fair in 1 case, with an excellent and good rate of 95.5%. X-ray films reexamination showed that all fractures healed with the healing time of 12-17 weeks (mean, 14.8 weeks). No internal fixation failure occurred. Rasmussen score, TPVA, and PTS at immediate after operation and at last follow-up were significantly superior to those before operation ( P<0.05). And there was no significant difference between immediately after operation and last follow-up ( P>0.05). CONCLUSION The treatment of Schatzker type Ⅴ and Ⅵ tibial plateau fractures with intermediate screw assisted reduction and fixation technique is reliable, which can reduce the difficulty of reduction and fixation, improve the efficiency of reduction and fixation, reduce the operation time, achieve satisfactory reduction and fixation effect and postoperative prognosis, and achieve good recovery of knee joint function.
Humans ; Tibial Fractures/diagnostic imaging* ; Male ; Female ; Adult ; Middle Aged ; Bone Screws ; Fracture Fixation, Internal/instrumentation* ; Retrospective Studies ; Adolescent ; Aged ; Young Adult ; Treatment Outcome ; Range of Motion, Articular ; Operative Time ; Length of Stay ; Tibial Plateau Fractures

OBJECTIVE: To evaluate the effectiveness of V-shaped stealth decompression technique using ultrasonic bone scalpel in anterior surgery for adjacent two-level cervical spondylosis. METHODS: A clinical data of 41 patients with adjacent two-level cervical spondylosis, who admitted between January 2020 and December 2023 and met the selection criteria, was analyzed retrospectively. Among them, 22 cases were treated with anterior cervical discectomy and fusion (ACDF) assisted by V-shaped stealth decompression technique using ultrasonic bone scalpel (group A) and 19 cases with anterior cervical corpectomy and fusion (ACCF) (group B). There was no significant difference between the two groups in age, gender, disease duration, surgical segment, preoperative Japanese Orthopedic Association (JOA) score, neck dysfunction index (NDI), pain visual analogue scale (VAS) score, and the anteroposterior diameter of the spinal canal in the responsibility space of axial CT ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage volume, hospital stay, complications during follow-up, JOA score, NDI, and VAS score at last follow-up, and the incidences of intervertebral fusion at 3 months after operation, and cage subsidence at last follow-up were compared between the two groups. RESULTS: The operations in the two groups were successfully completed. The operation time, intraoperative blood loss, postoperative drainage volume, and hospital stay in group A were significantly less than those in group B ( P<0.05). Two cases (9.1%) in group A and 4 cases (21.1%) in group B developed complications, with no significant difference in the incidence between the two groups ( P>0.05). All patients in the two groups were followed up 6-12 months (mean, 9.3 months). There was no significant difference in follow-up time between the two groups ( P>0.05). At last follow-up, the JOA score and VAS score in both groups significantly improved when compared with those before operation ( P<0.05). The change values of VAS score and the improvement rate of JOA score in group A were significantly superior to group B ( P<0.05). There was no significant difference in the change values of NDI and JOA score between the two group ( P>0.05). Imaging reexamination showed that the rate of intervertebral fusion at 3 months after operation was significantly higher in group A (81.8%) than in group B (52.6%) ( P<0.05), and all patients obtained bony intervertebral fusion at last follow-up. At last follow-up, 2 cases (9.1%) in group A and 11 cases (57.9%) in group B had cage sinking, and the difference in the incidence was significant ( P<0.05). No loosening or fracture of internal fixators occurred in all patients. CONCLUSION Using ultrasonic bone scalpel can transform single vertebral ACCF into two-segment ACDF in anterior cervical spondylosis surgery. The V-shaped stealth decompression technique is safe and efficient, with the advantages of minimal trauma, fewer postoperative complications, and rapid recovery of patients.
Humans ; Spondylosis/surgery* ; Male ; Female ; Middle Aged ; Decompression, Surgical/instrumentation* ; Retrospective Studies ; Cervical Vertebrae/surgery* ; Spinal Fusion/instrumentation* ; Diskectomy/instrumentation* ; Adult ; Treatment Outcome ; Aged ; Ultrasonic Surgical Procedures/methods* ; Operative Time

OBJECTIVE: To investigate the effects of combined platelet-rich plasma (PRP) and arterial supercharging technique on the survival rate and functional restoration of cross-body region skin flaps in rabbits. METHODS: Twelve healthy 6-month-old New Zealand White rabbits were randomly assigned to 4 groups ( n=3): sham group, PRP group, anastomosis group, and combined treatment group. An axial skin flap with an area of 12 cm×6 cm on the inner side of the hind limbs of all animals were prepared, with the saphenous artery as the main blood supply. Following the ligation of both the proximal and distal ends of the saphenous artery across all groups, the sham group received no further intervention, the PRP group was subjected to PRP injection, the anastomosis group underwent in situ end-to-end anastomosis of the distal saphenous artery, and the combined treatment group received both in situ distal saphenous artery anastomosis and PRP administration. Flap survival was evaluated and recorded on postoperative days 1, 3, and 7, with survival rates calculated accordingly. On day 7, flap tissue samples were harvested for HE staining to assess basal tissue morphology. Additionally, immunohistochemical staining was conducted to detect the expression of α-smooth muscle actin (α-SMA), vascular endothelial growth factor (VEGF), and CD31 in the flap tissues. RESULTS: At postoperative day 1, no significant difference in flap survival rates were observed among the 4 groups ( P>0.05). At day 3, the PRP group showed no significant difference compared to the sham group ( P>0.05); however, both the anastomosis and combined treatment groups exhibited significantly higher survival rates than the sham group ( P<0.05), the combined treatment group further demonstrated superior survival rates compared to both the PRP and anastomosis groups ( P<0.05). At day 7, the combined treatment group maintained significantly higher survival rates than all other groups ( P<0.05), while both the PRP and anastomosis groups exceeded the sham group ( P<0.05). HE staining at day 7 revealed persistent inflammatory cell infiltration, sheet-like erythrocyte deposition, and disordered collagen fibers in the sham group. The PRP group showed nascent microvessel formation and early collagen reorganization, whereas the anastomosis group displayed mature microvasculature with resolved interstitial edema. The combined treatment group exhibited differentiated microvessels with densely packed collagen bundles. Immunohistochemical analysis at day 7 demonstrated significantly larger relative area percentages of α-SMA, VEGF, and CD31 positive cells in the combined treatment group compared to all other groups ( P<0.05). Both the PRP and anastomosis groups also showed significantly higher values than the sham group ( P<0.05). CONCLUSION The combination of PRP and arterial supercharging techniques significantly enhances flap healing, potentially through mechanisms involving augmented angiogenesis and improved blood supply.
Animals ; Rabbits ; Platelet-Rich Plasma ; Surgical Flaps/blood supply* ; Graft Survival ; Anastomosis, Surgical/methods* ; Ischemia/surgery* ; Arteries/surgery* ; Skin/blood supply* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Skin Transplantation/methods*

Objective:To investigate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with rosacea, and to analyze the relationship between breath test results and the occurrence of rosacea.Methods:Patients with rosacea were enrolled from the outpatient department of Xiangya Hospital from March 2022 to June 2023. The methane-hydrogen breath test was used to detect intestinal levels of methane and hydrogen in all patients to investigate the prevalence of SIBO. The basic information, clinical symptoms and severity, quality of life scores, gastrointestinal symptoms, and past medical history of the patients were collected. Statistical analysis was carried out by using the chi-square test, nonparametric test and multivariate logistic regression models to investigate the relationship between SIBO and the occurrence of rosacea.Results:A total of 116 patients with rosacea completed the methane-hydrogen breath test. They were aged 18 to 56 years (median [ Q1, Q3]: 25 [22, 33] years), and included 7 males (6.0%) and 109 females (94.0%) ; there were 43 cases (37.1%) of erythematotelangiectatic rosacea, and 73 (62.9%) of papulopustular rosacea. As the breath test showed, 94 patients were diagnosed with SIBO (81.0%, 95% CI: 72.7% - 87.7%) based on the breath tests, 84 showed positive hydrogen breath test results (72.4%, 95% CI: 63.3% - 80.3%), and 47 had positive methane breath test results (40.5%, 95% CI: 31.5% - 50%). Among the 67 patients with moderate to severe erythema, 33 (49.3%) showed positive methane breath test results, and 14 of 49 (28.6%) patients with mild erythema showed positive methane breath test results, with a rate difference of 20.7% ( P = 0.025, 95% CI: 13.9% - 27.5%) ; there were no significant differences in the positive rates of SIBO and hydrogen breath test results between the patients with moderate to severe erythema and those with mild erythema (both P > 0.05). No significant differences were observed in the age, gender, clinical subtypes, severity of papulopustules, flushing and burning sensation, or rosacea quality of life index scores between the SIBO-positive and -negative groups, between hydrogen-positive and -negative groups, and between methane-positive and -negative groups (all P > 0.05). Multivariate logistic regression analysis showed that methane positivity on breath test was associated with the severity of erythema in rosacea ( OR = 2.495, 95% CI: 1.102 - 5.649, P < 0.05) . Conclusions:The prevalence of SIBO was relatively high in the patients with rosacea. However, only the positive rate of methane breath test differed between the rosacea patients and non-rosacea controls, and there was some correlation between methane positivity on breath test and increased severity of rosacea erythema.

Objective: To investigate the characteristics of newly reported HIV/AIDS cases aged 15 years and older in Shangcheng District, Hangzhou City from 2006 to 2022, so as to provide the basis for improving AIDS prevention and control strategies. Methods: Data of newly reported HIV/AIDS cases aged 15 years and older in Shangcheng District from 2006 to 2022 were collected through HIV/AIDS Comprehensive Control System of Chinese Disease Prevention and Control Information System. Population distribution and transmission routes were analyzed, and changing trends in case number were analyzed using average annual percent change (AAPC) and annual percent change (APC). Results: A total of 4 409 HIV/AIDS cases aged 15 years and older were newly reported in Shangcheng District from 2006 to 2022, including 3 932 males (89.18%). There were 3 447 cases (78.18%) under 50 years old and 962 cases (21.82%) being 50 years and older. Sexual contact was a predominant transmission route, with 4 326 cases accounting for 98.12%, including 2 626 cases (59.56%) with homosexual contact and 1 700 cases (38.56%) with heterosexual contact. The number of HIV/AIDS cases showed an overall upward trend from 2006 to 2022 (AAPC=13.038%, P<0.05), with an upward trend from 2006 to 2015 (APC=42.578%, P<0.05) and a downward trend from 2015 to 2022 (APC=-19.713%, P<0.05). The increase in the number of cases aged 50 years and older group was faster than that of cases aged under 50 years (AAPC=22.641% vs. 11.162%, both P<0.05). The increase in the number of cases with homosexual contact transmission was faster than that of cases with heterosexual contact transmission (AAPC=20.417% vs. 7.455%, both P<0.05). Conclusions The number of newly reported HIV/AIDS cases aged 15 years and older in Shangcheng District performed an overall upward trend from 2006 to 2022. The cases aged 50 years and older and transmitted through homosexual contact increased rapidly, which should be taken seriously.

Objective:To investigate the effects and mechanisms of zinc ion-loaded composite hydrogel (hereinafter referred to as the zinc-containing hydrogel) on infected full-thickness skin defect wounds in diabetic mice.Methods:This study was an experimental study. A poly (glycerol sebacate)-co-poly(ethylene glycol)-g-catechol prepolymer/quaternized-chitosan hydrogel (hereinafter referred to as the simple hydrogel) and a solid-state zinc-containing hydrogel with porous and good adhesion by adding zinc ions to the simple hydrogel were prepared. The release rate of zinc ions from the zinc-containing hydrogel after immersion in phosphate buffer solution (PBS) for 14 days was calculated. The concentration of methicillin-resistant Staphylococcus aureus (MRSA) cultured for 2 hours with the simple hydrogel, zinc-containing hydrogel, and PBS was measured. The scavenging ability of the simple hydrogel, zinc-containing hydrogel, and PBS for 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2, 4, 6-trinitrophenyl) hydrazyl (DPPH) was detected using microplate reader to reflect the ability of oxygen free radical removal. The length of vessels formed by human umbilical vein endothelial cells (HUVECs) cultured for 24 hours with the simple hydrogel, zinc-containing hydrogel, and PBS was measured. The cell viability of L929 cells cultured for 24 hours with the simple hydrogel, zinc-containing hydrogel, and PBS was detected using the cell counting kit-8. The mouse red blood cell suspension was divided into blank control group treated with PBS, simple hydrogel group, zinc-containing hydrogel group, and Triton X-100 group treated with corresponding solution. Hemolysis was detected using microplate reader after 2 hours of treatment, and the hemolysis rate was calculated. All experiments had a sample size of 3. Twenty-one C57BL/6J mice aged 6-8 weeks were taken, and a full-thickness skin defect wound was prepared in the symmetrical position on the back spine and infected with MRSA. Mice were divided into blank control group treated with PBS, simple hydrogel group, and zinc-containing hydrogel group treated with the corresponding hydrogel. Three days after injury, bacterial concentration in the wounds were measured in all groups of mice ( n=4). On day 0 (immediately), 3, 7, and 14 after injury, the wound infection status of mice was generally observed and the wound healing rate was calculated ( n=5). Hematoxylin-eosin staining and Masson staining were used to detect new epithelium and collagen formation in the wounds of mice on day 14 after injury. Immunofluorescence staining was used to detect neovascularization and distribution of M2 macrophages in the wounds of mice. Results:After immersion for 14 days, the release rate of zinc ions of the zinc-containing hydrogel was (70.5±4.6)%. Compared with the zinc-containing hydrogel, the bacterial concentration was significantly increased after 2 hours of culture with PBS and the simple hydrogel ( P<0.05). The DPPH scavenging rate of the zinc-containing hydrogel was significantly higher than that of PBS and the simple hydrogel (with P values all <0.05). The length of vessels formed by HUVECs cultured for 24 hours with the zinc-containing hydrogel was significantly longer than that cultured with PBS ( P<0.05). Compared with PBS and the simple hydrogel, the cell viability of L929 cells cultured for 24 hours with the zinc-containing hydrogel was significantly higher ( P<0.05). After 2 hours of incubation, compared with that in Triton X-100 group, the hemolysis rate of red blood cells in blank control, simple hydrogel, and zinc-containing hydrogel groups was significantly reduced ( P<0.05); and the hemolysis rate of red blood cells in the latter three groups was similar ( P>0.05). On day 3 after injury, the bacterial concentration in the wounds of mice in zinc-containing hydrogel group was significantly lower than that in blank control and simple hydrogel groups (with P values all <0.05). From day 3 to day 14 after injury, the wounds of mice in all the three groups were gradually healing, and on day 14 after injury, the wounds of mice in the zinc-containing hydrogel group were basically healed. On day 7 after injury, the wound healing rate of mice in zinc-containing hydrogel group was (72.4±8.4)%, which was significantly higher than that of blank control and simple hydrogel groups, being (31.6±6.7)% and (44.7±5.4)%, respectively(with P values all< 0.05). On day 14 after injury, the wound healing rate of mice in zinc-containing hydrogel group was (92.7±4.3)%, which was significantly higher than (73.5±7.4)% in blank control group ( P<0.05). On day 14 after injury, compared with that in blank control and simple hydrogel groups, the newly formed epidermis in mice wound of zinc-containing hydrogel group was longer and thicker, with more collagen deposition, and a more abundant distribution of new vessels and M2 macrophages. Conclusions:The zinc-containing hydrogel exhibits good biocompatibility, oxygen free radical scavenging capacity, and antimicrobial effects both in vitro and in vivo, as well as angiogenic promotion capability. It can provide sustained release of zinc ions to promote re-epithelialization and collagen synthesis, thus enhancing the healing of infected full-thickness skin defect wounds in diabetic mice.

Humans ; Clavicle ; Fractures, Bone/surgery*

OBJECTIVE: To investigate the effect of ultrasonic bone curette in anterior cervical spine surgery. METHODS: A clinical data of 63 patients with cervical spondylosis who were admitted between September 2019 and June 2021 and met the selection criteria was retrospectively analyzed. Among them, 32 cases were operated with conventional instruments (group A) and 31 cases with ultrasonic bone curette (group B). There was no significant difference between the two groups (P>0.05) in gender, age, surgical procedure, surgical segment and number of occupied cervical space, disease type and duration, comorbidities, and preoperative Japanese Orthopaedic Association (JOA) score, cervical dysfunction index (NDI), and pain visual analogue scale (VAS) score. The operation time, intraoperative bleeding, postoperative drainage, postoperative hospital stay, and the occurrence of postoperative complications were recorded in both groups. Before operation and at 1, 3, and 6 months after operation, the JOA score and NDI were used to evaluate the function and the postoperative JOA improvement rate was calculated, and VAS score was used to evaluate the pain improvement. The anteroposterior and lateral cervical X-ray films were taken at 1, 3, and 6 months after operation to observe whether there was any significant loosening and displacement of internal fixators. RESULTS: Compared with group A, group B had shorter operation time and postoperative hospital stay, less intraoperative bleeding and postoperative drainage, and the differences were significant (P<0.05). All incisions healed by first intention in the two groups, and postoperative complications occurred in 5 cases (15.6%) in group A and 2 cases (6.5%) in group B, showing no significant difference (P>0.05). All patients were followed up 6-12 months (mean, 7.9 months). The JOA score and improvement rate gradually increased in groups A and B after operation, while the VAS score and NDI gradually decreased. There was no significant difference in VAS score between 3 months and 1 month in group B (P>0.05), and there were significant differences between the other time points of each indicator in the two groups (P<0.05). At 1, 3, and 6 months after operation, the JOA score and improvement rate in group B were better than those in group A (P<0.05). X-ray films examination showed that there was no screw loosening or titanium plate displacement in the two groups after operation, and the intervertebral cage or titanium mesh significantly sank. CONCLUSION Compared with traditional instruments, the use of ultrasonic bone curette assisted osteotomy in anterior cervical spine surgery has the advantages of shorter operation time, less intraoperative bleeding, less postoperative drainage, and shorter hospital stay.
Humans ; Ultrasonics ; Retrospective Studies ; Titanium ; Postoperative Complications/epidemiology* ; Bone Plates ; Cervical Vertebrae/surgery*