近端锁定钢板治疗肱骨外科颈骨折合并肩关节脱位

目的探讨近端锁定钢板治疗肱骨外科颈骨折合并肩关节脱位的疗效。方法对13例肱骨外科颈骨折合并肩关节脱位患者行切开复位近端锁定钢板内固定。结果 13例均获随访,随访时间12～24个月。无感染、创口不愈合、骨折移位、内固定物松动和切割。术后4个月X线检查骨折均临床愈合。按照Constant评分方法:优11例,可1例,差1例。结论应用解剖锁定钢板治疗肱骨外科颈骨折合并肩关节脱位,临床效果较好。     

The cross‐pin retained implant supported restoration: a study of gasket placement and leakage

Background: Advantages of cross‐pin retained implant supported restorations (ISRs) include predictable retrieval and predictable retention. Unlike direct to fixture (DTF) or cement retained restorations, the prosthetic design of a cross‐pinned restoration retains gaps at the interfaces between the crown, abutment and cross‐pin screw. These spaces permit leakage into the suprastructure and gasket placement has been recommended to prevent this leakage. Methods: Five different gaskets were assessed for their ability to prevent leakage into a cross‐pinned ISR. The gaskets tested were: cement admixture on the cross‐pin screw; cement admixture on the inner surface of the coping and the cross‐pin screw; cement admixture on the inner surface of the coping only; cement admixture placed 1 mm from the margin of the coping and a filler placed in the abutment chimney. Results: Only gaskets which sealed both the cross‐pin screw interface and the abutment‐crown interface prevented leakage. A filler placed in the abutment chimney prevented leakage into this space but did not prevent fluid accumulating between the coping and abutment. Conservative placement of cement at the margin of the coping failed to prevent leakage. Conclusions: Cement gaskets may effectively prevent leakage into a cross‐pinned ISR. However, the use of a cement as a gasket has to be weighed against the issue of predictable retrieval, cement extrusion and incomplete seating.     

Interindividual anatomical variations affect the plate‐to‐bone fit during osteosynthesis of distal radius fractures

We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross‐sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three‐dimensional computer‐aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42° (0.30–0.56°) and 28.8° (9.9–44.9°), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate‐to‐bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:953–960, 2016.     

锁定钛板结合自固化磷酸钙人工骨治疗跟骨骨折

正2010年2月~2013年6月,我病区采用锁定钛板内固定结合自固化磷酸钙人工骨植骨治疗32例跟骨骨折患者,疗效满意,报道如下。1材料与方法1.1病例资料本组32例34足,均为男性,年龄21~61岁。左侧13足,右侧21足。均为闭合骨折。骨折根据Sanders分型:Ⅱ型18足,Ⅲ型13足,Ⅳ型3足。伤后至手术时间4~10 d。     

对侧皮质锁定技术治疗股骨远端骨折的研究近况

传统锁定螺钉装置存在刚度较高、近钢板侧应力集中的缺陷。近年来,因为传统锁定螺钉装置治疗股骨远端骨折愈合率较低,对侧皮质锁定技术（FCL）逐渐受到重视。其能降低传统锁定螺钉装置80%的固定强度,且保留锁定螺钉装置整体固定强度,提供弹性固定和骨折断端的平行微动,骨折端的骨痂生长较多、对称。在治疗骨折的理论上,FCL有新突破。在动物实验和初步临床应用中,可以使传统锁定螺钉装置治疗股骨远端骨折的愈合率提高。

     

Mature DC from skin and skin-draining LN retain the ability to acquire and efficiently present targeted antigen

Skin-draining LN contain several phenotypically distinguishable DC populations, which may be immature or mature. Mature DC are generally considered to have lost the capacity to acquire and present newly encountered Ag. Using antibody-opsonized liposomes as Ag carriers, we show that mature DC purified from skin explants are able to efficiently capture liposomes, process Ag encapsulated within them and activate Ag-specific CD4(+) T cells. Explant DC from mice with Langerhans cells (LC) expressing the primate diphtheria toxin receptor that were exposed to diphtheria toxin in vivo presented Ag as well as explant DC from wild-type mice, indicating that LC are not required and dermal DC are probably responsible for this presentation. We further show that all DC subtypes from LN that capture opsonized Ag are capable of cross-presenting it to CD8(+) T cells. Induction of additional maturation in vivo by LPS or treatment with double-stranded RNA did not alter the Ag presentation capacity of the skin or LN DC subtypes. These results suggest that mature DC present in skin-draining LN may play an important role in the induction of primary and/or secondary immune responses against Ag delivered to the LN that they take up by receptor-mediated endocytosis.     

Both Langerhans cells and interstitial DC cross-present melanoma antigens and efficiently activate antigen-specific CTL

Dendritic cells (DC) have a unique capacity to present external antigens to CD8(+) T cells, i.e. cross-presentation. However, it is not fully established whether the ability to cross-presentation is restricted to a unique subset of DC in humans. Here, we show that two major myeloid DC subsets, i.e. Langerhans cells (LC) and interstitial DC (Int-DC), have the ability to cross-present antigens to CD8(+) T cells in vitro. LC and Int-DC were obtained from DC generated by culturing human CD34(+)-hematopoietic progenitor cells with GM-CSF, FLT3-L, and TNF-alpha (CD34-DC). Both DC subsets were able to capture necrotic/apoptotic allogeneic melanoma cells and present antigens to CD8(+) T cells, resulting in efficient priming of naive CD8(+) T cells into CTL capable of killing melanoma cells. Strikingly, a single stimulation with either subset (LC or Int-DC) or total CD34-DC loaded with necrotic/apoptotic melanoma cells was sufficient to activate melanoma-specific memory CD8(+) T cells obtained from patients with metastatic melanoma to become effective CTL. Thus, this study provides the rationale to use CD34-DC loaded with necrotic/apoptotic allogeneic melanoma cells in a clinical trial.