Transforming Natural Eggshell and Diatomite into Bioactive Calcium Silicate Material for Bone Regeneration.

Calcium silicate (CS), a new and important bioceramic bone graft material, is prepared by using eggshells, which have a porous structure and are rich in calcium ions. Furthermore, the preparation of new CS materials using eggshells and diatomaceous earth minimizes their negative impact on the environment. In this study, we prepared CS materials using a high-temperature calcination method. The composition of the material was demonstrated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. Scanning electron microscopy (SEM) analysis confirmed the porous structure of the CS material. We also introduced ZnO to prepare ZnO-CS with antibacterial properties and showed that ZnO-CS exhibits excellent antibacterial effects through in vitro antibacterial experiments. Subsequent in vitro mineralization experiments demonstrated that ZnO-CS promoted the formation of a hydroxyapatite layer. Furthermore, in vitro cytotoxicity experiments demonstrated that ZnO-CS had very good biosafety and promoted cell proliferation. These findings were confirmed through subsequent cell proliferation experiments. Our results indicate that the novel ZnO-CS is a promising candidate for bone tissue engineering.

Osteoporosis treatment using stem cell-derived exosomes: a systematic review and meta-analysis of preclinical studies.

BACKGROUND: The increasing incidence of osteoporosis in recent years has aroused widespread public concern; however, existing effective treatments are limited. Therefore, new osteoporosis treatment methods, including stem cell transplantation and exosome therapy, have been proposed and are gaining momentum. Exosomes are considered to have greater potential for clinical application owing to their immunocompatibility. This study summarises the latest evidence demonstrating the efficacy of exosomes in improving bone loss in the treatment of osteoporosis. MAIN TEXT: This systematic review and meta-analyses searched PubMed, Embase, and Cochrane Library databases from inception to 26 March 2022 for osteoporosis treatment studies using stem cell-derived exosomes. Six endpoints were selected to determine efficacy: bone mineral density, trabecular bone volume/tissue volume fraction, trabecular number, trabecular separation, trabecular thickness, and cortical thickness. The search generated 366 citations. Eventually, 11 articles that included 15 controlled preclinical trials and 242 experimental animals (rats and mice) were included in the meta-analysis. CONCLUSION: The results were relatively robust and reliable despite some publication biases, suggesting that exosome treatment increased bone mass, improved bone microarchitecture, and enhanced bone strength compared with placebo treatments. Moreover, stem cell-derived exosomes may favour anabolism over catabolism, shifting the dynamic balance towards bone regeneration.

Lumbar Sympathetic Trunk Injury: An Underestimated Complication of Oblique Lateral Interbody Fusion.

OBJECTIVE: Lumbar sympathetic trunk (LST) injury is one of the major complications after oblique lumbar interbody fusion (OLIF). LST injury often manifests as unequal skin temperature in lower limbs after operation, and there may be a large number of missed diagnoses due to the lack of attention and different diagnostic methods. The study aimed to investigate the incidence and clinical characteristics of LST injury after OLIF. METHODS: The data of patients with lumbar degenerative diseases who underwent OLIF in our hospital from April 2016 to October 2017 were retrospectively analyzed. Finally, a total of 54 patients were included. There were 10 males and 44 females, aged 58.4 ± 10.9 years. The skin temperature of lower limbs was measured before and a day after surgery. The patients were followed up at 1 week, 6 weeks, 6 months, and 2 years after the surgery. Likert five-point scale was used to evaluate the discomfort caused by LST injury. Injury severity score was introduced to grade injury degree according to the recovery time of postoperative symptoms. The chi-square test was used to analyze the association of incidence of lumbar sympathetic trunk (LST) injury with contributing factors, such as gender and number of surgical segments. RESULTS: The unequal temperature was not found before surgery in all the patients. Postoperatively, 16 cases (29.6%) had difference of skin temperature more than 0.5 °C and were diagnosed with LST injury. Eight patients (14.8%) had self-perception of skin temperature differences, and 12 patients (22.2%) had other symptoms, such as muscle pain, numbness, and weakness, which were not statistically different between patients with and without lumbar sympathetic trunk injury (p > 0.05). In the 16 patients with LST injury, the difference of skin temperature between the two legs was 0.6 ± 0.1 °C on the first day, and the temperature difference lasted for 1.5-~12 months. According to Likert five-point scale, two cases (12.5%) were poor, and 14 cases (87.5%) were moderate immediately after surgery. Fifteen cases improved to some extent 6 weeks to 12 months after surgery. CONCLUSION: Postoperative LST injury is mainly manifested by different temperature of lower limbs. The incidence was higher in patients with multi-segment OLIF than in those with single-segment OLIF, and the subjective experience of most patients with LST injury was moderate discomfort.

[Single oblique lumbar interbody fusion with robot-assisted posterior internal fixation for lumbar degenerative diseases].

OBJECTIVE: To investigate the efficacy of single oblique lumbar interbody fusion(OLIF) with robot-assisted posterior internal fixation for the treatment of lumbar degenerative diseases. METHODS: The clinical data of 67 patients with lumbar degenerative diseases treated from September 2019 to December 2020 was retrospectively analyzed. According to different surgical methods, the patients were divided into traditional group and robot group. The traditional group received traditional OLIF with posterior fluoroscopy percutaneous nail fixation, and the robot group received OLIF with robot-assisted posterior internal fixation. There were 33 patients in traditional group, including 13 males and 20 females, aged from 44 to 82 years old with an average of (59.7±9.1) years; and 34 cases in robot group, including 7 males and 27 females, aged from 45 to 81 years old with an average of(61.6±8.8) years. The operation time, fluoroscopy time, intraoperative blood loss, postoperative out of bed time and hospital stay were recorded. The visual analogue scale (VAS) of low back pain and Oswestry Disability Index(ODI) were compared before operation and 3 days, 3 months after operation between two groups. The accuracy of nail placement was evaluated by postoperative CT scan. RESULTS: Both groups of patients successfully completed the operation and were followed up for more than 3 months. The operation time, fluoroscopy time, intraoperative blood loss, postoperative out of bed time and hospital stay in traditional group were(299.85±15.79) min, (62.58±10.83) min, (118.33±10.80) ml, (2.5±0.7) d, (9.67±2.13) d;and robot group was(248.53±14.22) min, (19.47±3.51) min, (115.74±9.86) ml, (2.3±0.6) d, (9.44±1.93) d, respectively. The symptoms of postoperative low back pain, lower limb pain and numbness were significantly improved in all patients. The operation time and fluoroscopy time in robot group were significantly less than those of traditional group. There was no significant difference in intraoperative blood loss, postoperative out of bed time, hospital stay, VAS and ODI before and after operation (P>0.05). The accuracy of nail placement in robot group was 98.8% (2/160), which was higher than 89.9% (16/158) in traditional group. CONCLUSION: Treatment of lumbar degenerative diseases with single body position OLIF with robot-assisted posterior minimally invasive internal fixation has less operation time and fluoroscopy time, high nail placement accuracy and accurate surgical effect, which is worthy to be popularized in clinic.