Malleostapedotomy for otosclerosis,our experience of nitinol piston on twelve patients

ObjectiveMalleostapedotomy allows to completely by-pass the incus in otosclerosis surgery. Recently its use has been rivaled by hydroxyapatite cement for cases of mild and moderate necrosis of the incus. However, it remains gold standard for cases of extensive necrosis, incus dislocation, or epitympanic fixation. Modern heat-crimping pistons make surgery easier and safer. This study focuses on our experience with this technique.MethodsRetrospective analysis of patient’s files and pre- and post-operative audiograms, for cases of surgically treated otosclerosis with malleostapedotomy.ResultsTwelve patients underwent malleostapedotomy for otosclerosis between 2011 and 2019. Amongst them there were 10 revision surgeries and 2 primary cases. 75% had incus long-process necrosis, 17% had epitympanic fixation and one had a history of incus transposition. Nine patients (75%) had closure of air-bone gap (ABG) of <10 dB (p < 0.001) and 11 (92%) had a threshold of 20 dB (p < 0.001). Mean pre-operative ABG was 31 dB (15 dB–55 dB), and mean post-operative ABG was 7 dB (0 dB–21 dB; p < 0.001). There was no sensorineural hearing loss nor any other post-operative complication.ConclusionsMalleostapedotomy is a safe and reliable technique, allowing an ABG closure comparable to conventional incus to vestibule prosthesis. It remains the preferred technique whenever the incus cannot be used.     

Chondrocyte-seeded hydroxyapatite for repair of large articular cartilage defects. A pilot study in the goat

The aim of this study was to evaluate the potential for restoration of a large cartilage defect in the goat knee with hydroxyapatite (HA) loaded with chondrocytes. Isolated chondrocytes were suspended in fibrin glue, seeded on top of the HA, and then the composite graft was implanted in the defect. After transplantation, cell behaviour, newly synthesised matrix and the HA–glue interface were assessed histologically after 2, 4, 12, 26 and 52 weeks. Special attention was paid to the incorporation process of HA in the subchondral bone and interactions between this biomaterial and the fibrin-glue–chondrocyte suspension.

Chondrocytes in the glue proved to survive the transplantation procedure and produced new metachromatically stained matrix two weeks after implantation. The glue–cell suspension had penetrated the superficial porous structure of the HA. Four weeks after surgery, islands of hyaline-like cartilage were observed at the HA–glue interface. A layer of fibrous tissue was formed surrounding the HA graft, resulting in a relatively instable fixation of the HA in the defect. This instability of the graft in the defect, possibly together with early weight bearing, resulted in a gradual loss of the newly formed hyaline cartilage-like repair tissue. Progressive resorption of the HA occurred without any sign of active bone remodelling from the host site. One year after surgery part of the defect which extended down to the cancellous bone had been predominantly restored with newly formed lamellar bone. Only small HA remnants were still present at the bottom of the original defect. Resurfacing of the joint had occurred with fibrocartilaginous repair tissue.

The absence of adequate fixation capacity of the HA near the joint space resulted in a relative instability of the graft with progressive resorption. Therefore, HA is not a suitable biomaterial to facilitate the repair of large articular cartilage defects.     

Disaggregation of bone into crystals

Summary The sizes, shapes, and organizational states of the crystals in bone are studied by systematic disaggregation of the mineral phase. This is achieved by oxidizing the organic phase with sodium hypochlorite, dispersing the resultant particles by sonication, and separating the crystal aggregates from the crystal monomers by gravity setting in ethanol. Six different bones are compared. Bones in which crystals are intimately associated with the collagen fibrils mostly disaggregate into crystal monomers. In dense bones, where the crystals are mostly located between fibrils, they tend to persist as “fused” aggregates. All the crystals are tabular or plate-shaped. In bones in which the majority of crystals are associated with the collagen fibrils, just less than 90% of the crystals are shorter than about 450 ? in length. Their widths are on the average about 250 ?, almost an order of magnitude larger than the diameters of individual gap regions within the collagen fibril. The notion that one crystal is located in one gap region is therefore untenable and a reevaluation of the relations between collagen and mineral in bone is necessary.     

羟基磷灰石涂层人工股骨柄的临床应用

自１９８９年１２月～１９９３年１１月，共收治各类髋关节病１４例（１５髋），均行ＦＵＲＬＯＮＧ羟基磷灰石（ＨＡ）涂层人工髋关节置换术。术后平均随访３２个月，髋关节功能按Ｈａｒｉｓ评分结果为平均９５分。无患肢疼痛和其它不适症状，亦无术后并发症发生。Ｘ线结果显示，股骨侧假体无松动、下沉表现，周围未见明显透亮线。术后３个月假体表面出现增生性骨反应，并在术后３～４年内逐渐增加。无明显骨萎缩表现。结合实验及临床研究结果，证明此种髋假体应用的短期疗效令人满意，其长期疗效尚有待进一步观察。     

PMMA/HA-GF医用复合材料制备及性能测试

本文主要研究了无机玻璃纤维增强聚甲基丙烯酸甲酯(PMMA)/羟基磷灰石(HA)复合材料的制备及相关的性能测试,证明此复合材料性能稳定、物理机械强度高以及工艺简单,有良好的应用前景。     

采用羟基磷灰石涂层股骨柄假体行全髋置换术的早期疗效

目的总结采用羟基磷灰石(HA)涂层股骨柄假体行全髋关节置换术的早期疗效。方法2000年2月～2003年10月,采用钛合金HA涂层股骨柄假体行无骨水泥全髋关节置换术65例(70髋)。术前诊断:股骨颈骨折30例,骨关节炎15例,股骨头缺血性坏死9例,人工股骨头术后松动8例,类风湿性髋关节炎2例,髋关节融合1例。分别于术后1周、3个月、6个月,以后每年一次行髋关节功能和X线片检查,其中44例接受双能X线骨密度仪(DEXA)的骨密度(BMD)检查。结果术后X线片提示股骨柄假体的初始固定均符合优良标准。随访2～5.5年,平均3年。髋关节功能从术前Harris平均评分32分(25～52分)恢复至最后随访时的平均96分(85～100分),至今无一髋表现股区痛或需行翻修手术。术后1年内的X线片测量显示:<1.5mm下沉者7髋,其余均无假体下沉。至今无一例显示股骨近端或髓内骨溶解,也无一例显示假体松动。DEXA检查显示BMD在术后下降,然后迅速恢复,3～6个月后可达到正常或接近正常水平,其中Ⅱ、Ⅵ区的BMD增加速度最快,有时甚至高于对照侧。按Engh标准评定,全部患者均获骨性固定。结论近段HA涂层能增强股骨柄假体的初始固定,促进早期骨长入和骨性生物学固定,阻止聚乙烯磨屑的髓内移行和骨溶解,故用于无骨水泥全髋置换术的早期疗效满意。     

Calcium environment in bone mineral determined by EXAFS spectroscopy

Summary Extended X-ray absorption fine structure (EXAFS) spectra were recorded, above the Ca K edge, from powdered mouse femurs. Spectra were interpreted on the basis of a model developed previously to explain the features of the EXAFS spectrum of fully crystalline hydroxyapatite. Eight shells of atoms surrounding Ca out of 0.57 nm were required to explain the appearance of the EXAFS spectrum of bone. Shell radii and Debye-Waller factors were systematically varied to obtain the best fit between observed and theoretical spectra, calculated using exact spherical wave theory. The results were closely similar to those obtained previously from the interpretation of EXAFS spectra from poorly crystalline hydroxyapatite prepared by maturation of amorphous calcium phosphate. However, there appears to be slightly more disorder in bone mineral, perhaps as a result of its accommodating carbonate ions     

Bone Replacement Materials in Hand Surgery

Abstract Background: In recent years, biomaterials are being found and frequently utilized in bone defects. They have also gained significant precedence in hand surgery. Objectives: The respective requirements for such replacement material will be cited and acknowledged in this article. The individual material groups will also be referred to in this review. An introduction to some of the customary bone replacement materials will be cited and concluded with a corresponding recommendation. Conclusion: The implantation of autologous cancellous bone is still regarded today as the “gold standard”. Nevertheless, the usage of bone replacement material can be an enormous advantage in certain indications. The original article can be found online at There was an error in the author’s affiliation and the address for correspondence was incomplete. Please note the correct institution and complete address: Department of Orthopedics and Traumatology, Hand-, Foot- and Reconstructive Surgery, Kreiskrankenhaus Gummersbach GmbH, Germany. Alexander von Friesen, MD Department of Orthopedics and Traumatology, Hand-, Foot- and Reconstructive Surgery Kreiskrankenhaus Gummersbach GmbH Wilhelm-Breckow-Allee 20 51643 Gummersbach Germany Phone (+49/2261) 171-575, Fax -449 e-mail: Friesen@kkh-gummersbach.de     

羟磷灰石加阿霉素瘤内注射治疗小鼠肝癌的实验研究

作者通过动物实验研究了羟磷灰石(HA)的抑癌效果及其机理。将80只移植有H_(22)肝癌的BALB/c小鼠分为4组:Ⅰ组HA加阿霉素(ADM)瘤内注射;Ⅱ组HA瘤内注射;Ⅲ组ADM瘤内注射;Ⅳ组未给药。结果Ⅰ～Ⅲ组的肿瘤生长抑制率分别为65.9％、41.9％及51.1％。Ⅰ～Ⅳ组的生存时间分别为32、22、26及18天。作者认为HA抑癌作用的机理可能是:①直接界面作用;②诱导组织纤维化;③免疫激活作用;④药物载体和缓释作用。结果显示HA加ADM瘤内注射可能成为一种治疗恶性肿瘤的新方法。     

The effect of surface chemistry modification of titanium alloy on signalling pathways in human osteoblasts

Establishing and maintaining mature bone at the bone–device interface is critical to the long-term success of prosthesis. Poor cell adhesion to orthopaedic and dental implants results in implant failure. Considerable effort has been devoted to alter the surface characteristics of these biomaterials in order to improve the initial interlocking of the device and skeleton. We investigated the effect of surface chemistry modification of titanium alloy (Ti–6Al–4V) with zinc, magnesium or alkoxide-derived hydroxy carbonate apatite (CHAP) on the regulation of key intracellular signalling proteins in human bone-derived cells (HBDC) cultured on these modified Ti–6Al–4V surfaces. Western blotting demonstrated that modifying Ti–6Al–4V with CHAP or Mg results in modulation of key intracellular signalling proteins. We showed an enhanced activation of Shc, a common point of integration between integrins and the Ras/Mapkinase pathway. Mapkinase pathway was also upregulated, suggesting its role in mediating osteoblastic cell interactions with biomaterials. The signalling pathway involving c-fos (member of the activated protein-1) was also shown to be upregulated in osteoblasts cultured on the Mg and CHAP modified Ti–6Al–4V. Thus surface modification with CHAP or Mg may contribute to successful osteoblast function and differentiation at the skeletal tissue–device interface.