Evaluation of resorption and biocompatibility of collagen hemostats in the spinal epidural space

Background contextCollagen hemostats have different characteristics depending on their properties and configuration. In vivo serial evaluation of local reactions because of placement of hemostats in the epidural space has not been reported.PurposeThis study compared the resorption and biocompatibility of two types of collagen hemostats placed in the epidural space.Study designThis in vivo study used experimental animals to evaluate collagen hemostats that were placed in the epidural space.MethodsA ligamentum flavum resection model was created in Japanese white rabbits (n=65). A microfibrillar collagen hemostat (MCH group, n=5), cotton-type collagen hemostat (CCH group, n=5) that was chemically cross-linked, or no hemostat (control group, n=4) was placed in the spinal epidural space. For histologic evaluation, each group was euthanized 1, 2, 4, and 8 weeks postoperatively (PO), and hematoxylin-eosin and immunohistochemical (IHC) staining for inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-6), cyclooxygenase (COX)-2, and macrophages (CD68) was performed. To evaluate exudate accumulation and the degree of inflammation in the epidural space, magnetic resonance imaging at 7.04 T was serially performed in each group (n=3) under anesthesia and sedation.ResultsThe collagen hemostats in both groups were reabsorbed at 4 weeks PO. In the MCH group, there was inflammatory cell infiltration and granuloma formation around the hemostat, TNF-α–positive cells were seen up to 1 week, and IL-6–, COX-2–, and CD68-positive cells were seen at all evaluation times. In the CCH group, no inflammatory cell infiltration around the hemostat was observed, and IHC staining showed no positive cells at 4 weeks PO and later. T2*-weighted MR images showed significantly higher mean signal intensity of the epidural space in the MCH group than in the CCH group but only at 1 week PO (p<.05).ConclusionsResorption of both hemostats was similar. In the MCH group, there was intense tissue inflammation around the hemostatic material, and MR images showed high signal intensity because of exudate accumulation in the epidural space. This indicated a strong foreign-body reaction to the MCH, thus demonstrating a difference in biocompatibility with the CCH.     

开胸前肺萎陷技术在胸腔镜手术中的应用

目的 采用开胸前肺萎陷技术评价不同支气管封堵时间对胸腔镜手术肺萎陷效果的影响。方法 选择2019 年8～12 月在我院行胸腔镜左肺楔形切除术的患者75 例,采用随机数字表法将其分为三组,每组各25 例。三组均采用开胸前肺萎陷技术,使用支气管封堵器行肺叶隔离。A 组患者支气管封堵8 min 后进胸,B 组患者支气管封堵10 min 后进胸,C 组患者支气管封堵12 min 后进胸。记录每组侧卧位即时（T0）和打开胸膜前（T1）的HR、SBP、DBP、SpO2、PaO2、PaCO2,并且各组到封堵时间点后即刻进胸,在胸腔镜直视下观察此刻的肺萎陷情况并评分。结果 与A 组比较,B 组和C 组患者的肺萎陷评分显著增加,差异有统计学意义（P＜0.05）;B 组和C 组之间的肺萎陷评分比较,差异无统计学意义（P＞0.05）。三组患者T1 时的PaO2 较T0 时显著下降（P＜0.05）;T1 时三组患者PaO2 组间比较,差异有统计学意义（统计值为F=5.193,P=0.008）;C 组患者T1 时SpO2 较T0 时显著下降（P＜0.05）;T1 时三组患者的SBP、DBP、HR 比较,差异无统计学意义（P＞0.05）。结论 开胸前肺萎陷技术对促进开胸前肺萎陷有效,对血流动力学无明显影响。支气管封堵10 min 既可达到良好的开胸前肺萎陷效果,又可保持良好的SpO2,适合作为胸腔镜进胸时机。     

Comparison of Rigid and Semirigid Fixation for Advancement Genioplasty

To compare the skeletal stability of rigid versus semirigid fixation for advancement genioplasty by the assessment of vertical and horizontal measurements pre-operatively and post-operatively on lateral cephalometric radiographs. The study comprised of patients who underwent standard advancement genioplasty by inferior osteotomy of the chin with broadest musculoperiosteal pedicle with either rigid fixation or wire fixation. The displacements of vertical and horizontal measurements resulting following surgery was derived by calculating the difference between preoperative, immediate post-operative and 1 year post-operatively on lateral cephalometric radiographs. Preoperative measurements were marked as T1, immediate post-operative as T2, 1 year follow up post-operative as T3. In the semirigid group a mean horizontal advancement of 5.97 mm was accompanied by a relapse of 1.623 mm during a period of minimum 1 year. The mean superior repositioning of menton was 0.7 mm. This was accompanied by a relapse of 0.325 mm during a period of 1 year. In the rigid group a mean horizontal advancement of 4.815 mm was accompanied by a relapse of 0.2 mm during a period of 1 year. The mean superior repositioning of menton was 0.975 mm. This was accompanied by a relapse of 0.1 mm during a period of 1 year. This study confirms the findings of several previous studies that contribute data specific towards the use of rigid fixation in advancement genioplasty. In our study we also observed that, in cases where large advancements are necessary, wire fixation may offer insufficient means of fixation particularly if the movement is complex and asymmetrical, in which case rigid fixation devices are more helpful.     

Condylar remodeling after osteosynthesis of fractures of the condylar head or close to the temporomandibular joint

PurposeCondylar head fractures (CHFs) are increasingly treated by open reduction and internal fixation (ORIF). However, there are no reports on the three-dimensional postoperative volumetric transformation of the condyle, especially with regard to fragmented cases. Protruding hardware can lead to severe complications, so the goal of this study was to examine the amount of condylar bony resorption occurring after ORIF.MethodsIncluded were surgically treated CHFs with eligible cone beam computer tomography (CBCT) datasets immediately after ORIF (T1) and after implant removal (T2), plus fractures of the condylar neck and base as a reference. 2D vertical and 3D volume changes of the condylar head after ORIF of CHFs were evaluated by CBCT datasets transformed into 3D models for 3D volumetric assessment using Slicer freeware.ResultsAmong a total of 50 fractures (38 patients), including 41 CHFs (ORIF with titanium positional screws, including 15 minor and 12 major fragmented cases) plus nine extracapsular fractures (eight upper neck and one base fracture), postoperative condylar volume decreased by a mean of 0.27 cm³ (median 0.25 cm³; SD 0.23 cm³) or 16% (median 14%; SD 11%). Major fragmented CHFs showed significantly higher resorption rates (p < 0.001, range 8–42%). Age correlated with a decrease in condylar volume (mean 2.4% per 10 years of age, (p = 0.011). No significant correlation could be established between loss of condylar volume and fracture localization. A protrusion of metallic implants was seen in 20% of the assessed cases.ConclusionDue to substantial volume changes of the condylar head occurring after ORIF, protrusion of implants (both metallic and resorbable) needs to be taken into consideration. An early removal of metallic ostheosyntesis material (around 4 months after ORIF) is strongly recommended to avoid adverse short- and long-term effects.     

可吸收小夹板用于内固定的动物实验研究

目的 探讨可吸收小夹板置入后的生物降解过程及其对骨折愈合的影响，以期为临床应用提供参考。方法 成年新西兰大耳白家兔15只，用裂钻将双侧颧弓截断，一侧用LactoSorb可吸收小夹板固定，另一侧用相同大小的小钛板固定作为对照。术后4、12、24周处死动物，每组5只，进行放射学、大体观察和组织学检查。结果 术后4周时，所置可吸收夹板由透明变为乳黄色不透明状，体积较置入时膨大；X线及组织学检查见骨断端间有新骨形成，与对照组的新骨形成无明显差异。镜下未见急、慢性炎性细胞浸润。12周时，可吸收小夹板崩解为碎颗粒状，置入体积明显吸收，夹板轮廓仍然可辨；X线检查见实验组及对照组骨折线均消失，骨连续已完全建立；组织学检查见骨断端已由新骨连结。24周时，所置可吸收夹板已完全吸收,仅在骨孔内有可吸收螺钉残留；X线及镜下见两组骨折已完全愈合，为成熟的板状骨，形态学上无差异。结论 LactoSorb可吸收小夹板具有良好的生物相容性，在体内以崩解的方式进行降解，完全吸收约需半年。用于非承重或承重较小的部位，可提供与金属夹板相同的稳定性，且骨折最终愈合与金属夹板固定时无差异。     

Post-operative computed tomographic imaging of the shoulder joint

Between 1984 and 1990 312 patients underwent surgery for habitual or recurrent shoulder dislocation. Out then, 65 had a post-operative CT examination. This retrospective study was launched to demonstrate the value of CT in post-operative shoulder imaging. In most cases, CT was done using standardised techniques without contrast medium. Except in 4 cases, an intra-articular double-contrast technique was used. Evaluation was focused on 41 cases after implantation of a wedged bone graft in cases of primary or secondary flat glenoid or widening of a small glenoid with cortical consoles and bone block. The results demonstrate the effectiveness of standardised CT technique in that all necessary information concerning stabilisation of the shoulder joint, sufficient implant of bone grafts and assessment of correct inclination after osteotomy were obtained. Correspondence to: G. Helweg     

Effect of ethane-1-hydroxy-1,1-diphosphonate (EHDP) and dichloromethylene diphosphonate (Cl2MDP) on the calcification and resorption of cartilage and bone in the tibial epiphysis and metaphysis of rats

Young male rats (70–90 g) were treated for various periods with several doses of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) or disodium dichloromethylene diphosphonate (Cl₂MDP). Effects of treatment on the changes in the thickness, growth and mineralization of proximal growth plate and metaphysis of the tibia were assessed histologically and by micro-radiography. High doses (10 or 30 mg P/kg/day) of EHDP impaired mineralization of the growth cartilage, which became increased in thickness, and of the osteoid in the metaphysis and diaphysis. Matrix formation continued, although at a diminished rate. High doses (10 or 30 mg P/kg/day) of Cl₂MDP produced a different effect. There was no inhibition of mineralization, but there was a marked impairment of normal metaphyseal remodelling, with persistence of columns of calcified cartilage. Resorption at the periosteal surface in the metaphysis was also inhibited, so that the metaphysis became club-shaped. Osteoclasts were present in large numbers in the metaphysis, but their appearance was abnormal and similar to that seen in human osteopetrosis.     

Licht- und elektronenmikroskopische untersuchungen über die lokalen reaktionen auf implantiertes kollagen-haemostypticum —Eine tierexperimentelle studie

Zusammenfassung Licht- und elektronenmikroskopisch werden an 132 Wistar-Ratten die morphologischen Reaktionen auf Implantation von hämostyptisch wirksamem, nativem Kollagen-Vlies in die Subcutis und auf eine blutende Leberwunde untersucht. In der Subcutis vermittelt das Einwandern von Mikround Makrophagen eine problemlose Resorption des Kollagens. Eine bindegewebige Organisation der Implantationszone erfolgt vom 5. bis 15. Tag p.o. Überschießendes Bindegewebe ist nach 25 Tagen, Fremdkörpergranulome sind nach 50-100 Tagen p.o. abgebaut. Die besonderen Merkmale der Applikation auf die blutende Leberwunde sind rasche Blutstillung, Mesothelisierung des Vlieses gegenüber der Bauchhöhle nach 1 Tag, Resorption und Organisation ohne Bildung von Verwachsungen bis zum 10. Tag p.o. Die Ausheilung erfolgt in Form einer flachen Verdickung der Leberkapsel und vereinzelten restlichen Fremdkörpergranulomen nach 100 Tagen.

---

Light and electron microscopic studies on local reactions to implanted collagen hemostypticum — An experimental study

Summary A light and electron microscopic study was made on the resorption of native collagen fleece following its subcutaneous implantation or its application on a bleeding liver surface in 132 Wistar rats. Resorption of collagen began with the immigration of micro- and macrophages. Organisation of subcutaneous connective tissue was seen from day 5 p.o. to day 15 p.o. The excessive connective tissue was removed after 25 days and foreign body granulomas were eliminated after 50 to 100 days. Typical characteristics of application of the collagen fleece on bleeding liver surface are: Rapid hemostasis, mesothelisation of collagen towards the peritoneum after 1 day, resorption and organisation without adhesion after 10 days. The final heeling leads to a smooth thickening of the liver capsula with a few residual granulomas after 100 days.

     

The influence of ovarian sonication on fetal development in the rat

This study was undertaken to determine whether sonication of the ovaries on day 8 of pregnancy would alter fetal development in the rat. Mating was confirmed by the presence of sperm (day 1 of gestation) in the vaginal smear, and the rats were grouped and treated on day 8 as follows: Group I (controls) had both ovaries surgically exposed to sonic gel for 10 min/ovary; group II received 10 watts/cm² temporal peak intensity of pulsed ultrasound through the body wall for 10 min/ovary; group III received 100 watts/cm² in a similar manner as group II; group IV was treated the same as group III except the ultrasound was applied directly to the surgically exposed ovaries. The frequency employed was 1.9 mHz. The animals were sacrificed on days 15–17, implantation sites and resorptions were counted, and fetal viability was determined. There were no statistically significant differences in the percentage of resorptions among any of the groups. The data indicated that the ovaries were functional with regard to fetal development.     

Osteoprotegerin deficiency attenuates strontium‐mediated inhibition of osteoclastogenesis and bone resorption

Strontium (Sr) exerts an anabolic and antiresorptive effect on bone, but the mechanism remains unknown. Osteoprotegerin (OPG) expressed by osteoblasts plays an important role in regulating bone homeostasis by inhibiting osteoclastogenesis and bone resorption. This study aims at evaluating the role of OPG in Sr‐mediated inhibition of osteoclastogenesis and bone resorption. Six‐week‐old Opg knockout (KO) male mice and their wild‐type (WT) littermates were treated orally with vehicle (Veh) or Sr compound (4 mmol/kg) daily for 8 weeks. Bone mass and microstructure in the lumbar spine (L₄) and proximal tibia were analyzed with micro–computed tomography (µCT). Bone remodeling was evaluated with serum biochemical analysis and static and dynamic bone histomorphometry. Osteoclast differentiation potential and gene expression were analyzed in bone marrow cells. The findings demonstrate that Sr compound treatment results in greater bone volume and trabecular number than Veh treatment in WT mice. The anabolic response of trabecular bone to Sr treatment is attenuated in KO mice. Although Sr treatment significantly decreases in vitro osteoclastogenesis and bone resorption in WT mice, these effects are attenuated in KO mice. Furthermore, Sr treatment profoundly increases Opg gene expression in the tibias and OPG protein levels in the sera of WT mice. This study concludes that the inhibition of osteoclastogenesis and bone resorption is possibly associated with OPG upregulation by Sr treatment. © 2011 American Society for Bone and Mineral Research.