多孔聚乙烯板修复眼眶爆裂性骨折

目的探讨多孔聚乙烯（Medpor）板在眶壁爆裂性骨折修复术中应用的临床效果。方法对67例（67只眼）眼眶爆裂性骨折,应用Medpor板进行修复手术。术后随访6个月～2年观察眼球突出度、眼球运动及复视等指标。结果术前眼球突出度检查,患眼与对侧眼眼球突出度相差1．0—8．0平均（3．6±1．4）mm,差异具有统计学意义（t=19．884,P=0．000）;手术后3个月,患眼手术前后眼球突出度比较,相差0．0～7．0（3．2±1．4）mm,差异具有统计学意义（t=19．192,P=0．000）;术前65只眼眼球运动受限牵引试验阳性并伴有不同程度复视,手术后3个月,眼球运动受限者中有60例（92．3％）治愈,复视完全消失;5例（7．7％）30°视野范围外仍有复视,但对日常生活无明显影响。结论Medpor板修复眶壁骨折是一种安全有效、方便、可靠的手术方法。     

Medpor治疗眼眶爆裂性骨折的手术效果

目的探讨眼眶爆裂性骨折用Medpor填充治疗的手术效果。方法2003年9月～2006年5月经不同入路开眶术用Medpor填充治疗78例眼眶爆裂性骨折。结果手术后对眼球内陷疗效的分析,早期治愈率92%,晚期手术治愈率72%,早期手术明显优于晚期手术;手术后对复视的疗效分析,早期手术中有效率84%,晚期手术中有效率为56%,早期手术明显优于晚期手术。结论早期采用Medpor眶壁修补术是治疗眶壁爆裂性骨折的有效方法;术中充分松解嵌顿的眼外肌防止再粘连是消除复视的关键。     

高密度多孔聚乙烯材料行眶缘凹陷充填再造术

目的 探讨采用Medpor高密度多孔聚乙烯生物材料行眶缘凹陷充填再造术的效果和安全性。方法 对行Medpor高密度多孔聚乙烯生物材料眶缘凹陷充填再造术16例患者的预后进行追踪随访。结果 用Medpor行眶缘凹陷充填再造术16例,均获满意效果。随访1～4年,平均2．4年,未见植入物脱出、移位及吸收等并发症。结论 Medpor是一种良好的骨替代材料,明显优于自体组织及其他人工材料。(中华眼科杂志,2004,40：377-379)     

多孔聚乙烯义眼座植入术治疗复杂性眼窝畸形

目的探讨多孔聚乙烯义眼座植入术对复杂性眼窝畸形的手术治疗方法和临床效果.方法对30例无眼球或眼球萎缩伴眼窝塌陷畸形的患者,行高密度多孔聚乙烯(high-density porous polyethylene,MEDPOR)义眼座植入联合穹隆成形术.结果所有患者眼窝畸形均得以矫正,随访3月～2年,义眼座在眼眶内无脱出、移位或感染.装入仿真义眼片后,双眼对称,义眼活动度可达10°～20°度.结论多孔聚乙烯义眼座植入联合穹隆成形术矫治复杂性眼窝畸形在总体上取得了良好的效果.多孔聚乙烯义眼座具有良好的组织相容性,是矫正眼窝塌陷畸形的理想材料.     

高密度多孔聚乙烯在眶骨折整复中的应用

目的 观察高密度多孔聚乙烯(Medpor)应用于眶爆裂性骨折整复术的效果。方法 应用Medpor作为修补眶壁骨折缺损的充填材料行眶爆裂性骨折整复术31例。结果 术后2周内检查31例复视均好转，术后1．5～8月检查复视治愈27例。31例术后7～10天伤眼眼球突出度增至10．5～14．5mm，平均13．3mm；术后伤眼与健眼眼球突出度之差为 1．5～-2．0mm，平均为 0．9mm。术后CT显示：植入的Medpor薄片位置良好，无移动或脱位。眶内容物复位良好。视神经无受压。结论 Medpor是一种理想的修补眶壁骨折缺损的充填材料.     

The survival of freely grafted orbital fat on porous polyethylene orbital implants in the rabbit

PURPOSE: To investigate the long term survival of orbital fat grafted on a Medpor implant as a method of preventing porous polyethylene orbital implant (Medpor) exposure in anophthalmic sockets. METHODS: In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor implant and overlying conjunctiva, during the enucleation and Medpor implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperatively and grafted orbital fats were examined by light microscopy. RESULTS: Grafted orbital fat was well-maintained at 2 and 4 weeks, postoperatively. However, fat amounts were significantly reduced at 8 weeks, and viable fat was barely visible at 12 weeks. CONCLUSIONS: In rabbits, orbital fat grafted on Medpor implants was gradually resorbed, and the fat-occupied volume was not maintained.     

高密度多孔聚乙烯修复眶缘缺损的临床观察

目的：评价用高密度多孔聚乙烯修复眶缘凹陷性骨折的效果。方法：采用较新型的整形外科材料——高密度多孔聚乙烯(Medpor)治疗眶缘骨缺损，共治疗10例患者。结果：全部患者外观明显改善。结论：高密度多孔聚乙烯是修复眶缘骨缺损的较理想的材料。     

Magnetic resonance imaging assessment of fibrovascular ingrowth into porous polyethylene orbital implants

BACKGROUND: To evaluate fibrovascular ingrowth into porous polyethylene orbital implants, using serial gadolinium (Gd)-enhanced magnetic resonance imaging (MRI). METHODS: 40 rabbits were divided into two groups, according to the surgical techniques used. Group 1 underwent enucleation of one eye and Medpor implantation, group 2 underwent evisceration and Medpor implantation. All subjects from each group were examined via MRI, and the implants were assessed histologically on the first, second, fourth and eighth postoperative weeks. The degree to which fibrovascular ingrowth occurred was then assessed by measuring the Gd-enhanced portion via MRI, as well as by histologic examination. RESULTS: There was a significant correlation between the enhanced area on MRI and the fibrovascularized area observed upon histological examination in the two study groups (group 1: r = 0.850 P < 0.001, group 2: r = 0.788, P < 0.001). The area enhanced on MRI was 2.70% smaller in mean value than the fibrovascularized area observed upon histological examination. There was no differences in fibrovascular ingrowth between group 1 and 2. It was also found that there was no differences between the two groups with regard to the enhanced areas on MRI. CONCLUSION: Gd-enhanced MRI study proved to be an excellent method for the assessment of fibrovascular ingrowth into the Medpor orbital implants, after both enucleation and evisceration.     

Primary placement of a motility coupling post in porous polyethylene orbital implants

The placement of a motility coupling post (MCP) to integrate the prosthesis with a porous orbital implant may enhance prosthetic motility following enucleation. Previously, MCP placement has required a second operation usually at least 6 months following enucleation. We developed a technique to place an MCP reliably and safely into a porous orbital implant at the time of enucleation. Eligibility criteria included high motivation to achieve maximal prosthetic motility, adequate conjunctiva to ensure desirable wound closure, and isolation of the 4 rectus muscles. Enucleation was performed in standard fashion with implantation of a conical porous polyethylene orbital implant. Implanted MCPs protruded anteriorly 2 to 4 mm. The Tenon capsule and conjunctiva were closed in separate layers over the protruding MCP. Thirty-two patients underwent primary placement. Follow-up ranged from 1 to 33 months (mean, 15 months). Nine MCPs spontaneously exposed within the first 4 months. One additional post autoexposed at 12 months. Three patients underwent a secondary procedure to expose the MCP. There were no cases of infection, explantation, or gross MCP malposition. Minor complications included pyogenic granuloma (n=2) and conjunctival overgrowth (n=1). All patients were successfully fit with prostheses. Prosthetic motility was acceptable in all patients. Motility coupling post placement at the time of enucleation surgery in selected patients is an effective, efficient surgical option. Arch Ophthalmol. 2000;118:826-832     

Fibrovascular ingrowth into hydroxyapatite and porous polyethylene orbital implants wrapped with acellular dermis

PURPOSE: Acellular dermis is a frequently used wrapping material for hydroxyapatite (HA) and porous polyethylene (PP) orbital implants. In an animal model, we determined by histology the extent of fibrovascular ingrowth within orbital implants wrapped in acellular dermis at 6 and 12 weeks after surgery. METHODS: Four Yucatan minipigs were used for the study. Two minipigs had HA implants and two had PP implants. Implants were harvested at 6 or 12 weeks after surgery and were examined histologically for fibrovascular ingrowth. RESULTS: There was complete fibrovascularization of HA implants harvested at both 6 and 12 weeks after surgery. The PP implant harvested at 6 weeks had incomplete fibrovascularization, whereas the PP implant harvested at 12 weeks had complete fibrovascular ingrowth. There was no histologic evidence of inflammation seen in any of the orbital implants. On gross and histologic examination, the wraps were found to persist on the surface of all orbital implants, with little histologic evidence of inflammation localized to the acellular dermis. CONCLUSIONS: Acellular dermis wraps support fibrovascularization of both HA and PP orbital implants. Additionally, acellular dermis does not incite significant inflammation in association with HA and PP orbital implants and can persist in situ for at least 12 weeks after surgery.     

Oculoplastic and orbital surgery

Familiarity with facial anatomy, anesthetic agents, and techniques allows the surgeon to maximize his or her surgical success. Reduction of perioperative complications such as an uncooperative or agitated patient may be reduced with proper anesthesia techniques. This ultimately leads to higher success rates and increased patient and physician satisfaction.     

Effect of synthetic bone glass particulate on the fibrovascularization of porous polyethylene orbital implants

PURPOSE: To determine the effects of synthetic bone glass particulate (BG) on the fibrovascular ingrowth that occurs in porous polyethylene orbital implants (PP). METHODS: Forty-eight rabbits were divided into 4 groups, according to the different surgical techniques and implanted materials used. Group 1 was enucleated and implanted with PP, group 2 underwent evisceration and was implanted with PP, group 3 was enucleated and implanted with BG, and group 4 underwent evisceration and was implanted with BG. All of the implants in each group were histologically assessed at postoperative weeks 1, 2, 4, and 8. RESULTS: There was no statistically significant difference with regard to fibrovascular ingrowth in the 4 groups. A greater number of vessels per unit area and mature fibrous tissue were found in the outermost zone for a longer time after implantation, but we found no statistically significant differences among the 4 groups. CONCLUSIONS: We conclude that inclusion of synthetic bone glass particulate did not result in any significant increases in the rates of fibrovascular ingrowth in porous polyethylene orbital implants in rabbits.     

The quasi-integrated porous polyethylene orbital implant

PURPOSE: To describe a new quasi-integrated porous polyethylene orbital implant that combines the advantages of host tissue incorporation and improved motility with a single-stage surgery. METHODS: Twenty-four consecutive patients undergoing primary or secondary orbital implantation received the quasi-integrated porous polyethylene implant. Approximately 6 weeks after implantation, a custom-fitted prosthesis was made by an impression technique to provide a "lock-and-key" fit with the orbital implant. Postoperative complications and motility of the prosthetic shell were evaluated. RESULTS: During the 27-month period between December 1998 and March 2001, 24 patients received the quasi-integrated porous polyethylene implant as a buried orbital implant. Thirteen patients received the implant as a primary orbital implant after either evisceration or enucleation and 11 patients received the implant as a secondary orbital implant. Follow-up ranged from 3 months to 30 months, with an average of 16.9 months. All patients were considered to have good motility of their prosthetic shell at their final follow-up visit. No cases of implant extrusion or migration were noted. Two patients required deepening of their inferior fornix to accommodate the increased motility of their prosthesis. CONCLUSIONS: The new quasi-integrated porous polyethylene orbital implant provides improved motility without the need for secondary placement of pegs or screws. It has the advantage of biocompatibility, allowing host tissue incorporation to resist implant migration and extrusion. The implant is available in three sizes: small, medium, and large, approximating the volume of a 16-, 18-, and 20-millimeter sphere, respectively.