Orbital reconstruction with proplast

Blow-Out Fracture of the Orbital Floor in Early Childhood

Because of the anatomy of the developing bones in early childhood, blow-out fractures are rare before the age of 8 years. We present two cases where after a fall, computed tomography examinations revealed a blow-out fracture of the left orbital floor in a 12-month-old child and 27-month-old child. Because no associated symptoms were noted, both cases were managed conservatively.

A comparison of parietal and iliac crest bone grafts for orbital reconstruction

PURPOSE

This study evaluated the results of cranial (membranous) versus iliac crest (endochondral) bone grafts as implants to correct post-traumatic globe malposition and/or diplopia.

PATIENTS AND METHODS

Twenty-two patients underwent 25 orbital reconstructions with bone for enophthalmos, hypophthalmos, and diplopia after trauma to the orbit. Inclusion criteria consisted of at least 4 months postsurgical follow-up, pre- and postsurgical quantitative orbital measurements, photographic documentation, and complete medical records regarding inpatient and outpatient data.

RESULTS

Nine cranial bone grafts and 16 iliac crest grafts were placed. Ages were similar in both groups. The average follow-up was 24 months for the cranial graft group (range, 4 to 54 months) and 18 months for the iliac crest graft group (range, 4 to 51 months). Preoperative enophthalmos averaged 4.11 and 5.06 mm in the cranial and iliac crest groups, respectively, and postoperatively the measurements were 1.78 and 1.37 mm, respectively. Changes in hypophthalmos generally reflected changes in the enophthalmos correction. In 10 patients diplopia was corrected by the procedure. There was a statistically significant change in the enophthalmos of patients when comparing pre- and postoperative status, but no statistically significant difference between the results of the cranial and iliac crest graft groups.

CONCLUSION

There is no difference in the ability of cranial and iliac crest bone grafts to correct post-traumatic enophthalmos.

Physical and biocompatibility properties of poly-epsilon-caprolactone produced using in situ polymerisation: a novel manufacturing technique for long-fibre composite materials

Preliminary investigations into a novel process for the production of poly-epsilon-caprolactone (PCL) to be used as a matrix material in a bioabsorbable composite material are detailed. This material is primarily being developed as a bone substitute for use in maxillofacial reconstructive surgery, however, the technique described could be adapted to other areas where bioabsorbable composite materials may be used. The development of a totally bioabsorbable long-fibre composite material would allow a two-stage degradation to occur with the matrix material degrading first leaving a scaffold structure of degradable fibres which would be absorbed at a later stage. Caprolactone monomer was polymerised in situ within a tool cavity to produce a net shape moulding. Inclusion of a fibre preform within the tool cavity which was impregnated by the liquid monomer produces a long-fibre composite material. PCL with a range of molecular weights has been produced using this liquid moulding technique to assess the physical and biocompatibility properties compared to commercially available PCL. Osteoblast-like cells derived from human craniofacial bone (CFC) have been used to assess the in vitro biocompatibility of the PCL. The results show that high-quality PCL with a narrow molecular weight distribution and properties similar to commercially available PCL can be produced using this technique. Polymerisation of the monomer around a woven fibre preform made of a poly(lactic acid) (PLA)/poly(glycolic acid) (PGA) copolymer (vicryl mesh) produced a bioabsorbable long-fibre composite material. Further work is ongoing to develop this system towards a method for improving craniofacial bone reconstruction.

Enucleation

The three most common indications for enucleation are intraocular malignancy, trauma, and a blind, painful eye. Recommending enucleation is one of the most difficult therapeutic decisions in ophthalmology. In some cases of malignancy, cryotherapy, laser photocoagulation, diathermy, chemotherapy, and radiation therapy may be viable alternatives to surgery. When surgery is chosen, evisceration or exenteration may be alternatives to enucleation. Once the decision is made to perform enucleation or evisceration, the surgeon must choose from several types of implants and wrapping materials. These devices can be synthetic, autologous, or eye-banked tissues. With certain implants, the surgeon must decide when and if to drill for subsequent peg placement. In this review, the authors discuss choices, techniques, complications, and patient consent and follow-up before, during, and after enucleation. Controversies and results of the Controlled Ocular Melanoma Study are summarized.

Pyriform augmentation as an ancillary procedure in facial rejuvenation surgery

A patient is presented in whom augmentation of the pyriform aperture of the maxilla was performed with porous hydroxyapatite in concert with a face and brow lift. Basic research has recently shown that remodeling of the facial skeleton continues throughout life and that this remodeling process leads to changes in the position of several key areas. The pyriform aperture was identified as one region that remodels in a posterior direction, leading to retrusion of the alar base in the older individual. This skeletal retrusion occurs in a very site-specific fashion, and its effects are reflected on the overlying soft tissues of the face. With aging, remodeling of the pyriform aperture posteriorly causes the alar base to appear recessed and decreases the nasolabial angle, changes that are noted on the profile of the older individual. Augmentation of the pyriform aperture can be achieved through a buccal sulcus incision and, when used in conjunction with standard facial rejuvenation procedures, can improve the overall result in facial cosmetic surgery.

Complications and toxicities of implantable biomaterials used in facial reconstructive and aesthetic surgery: a comprehensive review of the literature

The use of implantable biomaterials has become an integral part of aesthetic and reconstructive surgery of the face. Metals are used for fracture fixation devices, whereas polymers are used primarily for bone or soft-tissue substitution. This review of the scientific literature examines the risks and complications of these materials. First, we present an overview of commonly used materials. Second, we address general considerations of toxicity relevant to all biomaterials. Third, we present data from a large number of clinical series on the incidence of complications for individual materials used in specific applications.

Use of Proplast II as a subperiosteal implant for the correction of anophthalmic enophthalmos

BACKGROUND

A variety of autogenous and alloplastic materials have been used as subperiosteal implants to correct anophthalmic enophthalmos. Proplast II is a synthetic porous composite of Teflon polymer and alumina. Proplast II offers a number of advantages over other commonly used alloplastic materials such as silicone and polymethyl methacrylate. It is light, porous, resilient, malleable, and easy to shape. It can be readily sterilised after shaping. It has been found to integrate with the surrounding tissues, thereby minimising the risk of subsequent implant migration and extrusion.

METHODS

Proplast II was used as a subperiosteal implant in a total of 15 anophthalmic patients during the period June 1990 to March 1994. The indication for this procedure in all patients was poor orbital volume replacement despite the prior insertion of an adequately sized spherical socket implant.

RESULTS

The results were excellent with a good correction of preoperative upper eyelid sulcus deformity. There were no operative complications nor any serious postoperative complications. The implants were well tolerated.

CONCLUSION

Proplast II can be highly recommended for use as a subperiosteal implant.

Self-reinforced polyglycolic acid membrane: a bioresorbable material for orbital floor repair. Initial clinical report

A self-reinforced polyglycolic acid membrane has been used successfully to repair 15 orbital floor fractures in 12 consecutive patients. As polyglycolic acid is absorbable it does not cause the complications of long-term infection and migration associated with non-absorbable bioinert alloplastic repair materials.

Experimental evaluation of expanded polytetrafluoroethylene for reconstruction of orbital floor defects

OBJECTIVE

This study evaluates the efficacy of a medical grade expanded polytetrafluoroethylene (e-PTFE) sheet for reconstruction of the orbital floor.

MATERIALS AND METHODS

Orbital floor defects were created in 10 domestic sheep and reconstructed with the 1-mm thick e-PTFE sheet. The surgical sites were evaluated for the development of enophthalmos and biocompatibility at 2 weeks, and at 1-, 2-, 4-, and 6-months intervals.

RESULTS

The results of this indicate that the e-PTFE material has excellent handling characteristics, provides stability to correct surgically created enophthalmos, and causes essentially no foreign body reaction.

CONCLUSION

Expanded polytetrafluoroethylene proved to be an excellent alloplastic material for the repair of orbital floor defects in this experimental study.