Spherical Implants Research Articles

Enucleation With Hydroxyapatite Implantation Versus Evisceration Plus Scleral Quadrisection and Alloplastic Implantation

To compare the motility and complications of enucleation with evisceration plus scleral quadrisection. In a prospective study between January 2006 and June 2007, 50 patients underwent evisceration with scleral quadrisection and alloplastic implantation (group 1) and 50 patients underwent enucleation and hydroxyapatite implantation (group 2). Horizontal and vertical excursions of implants and complications such as exposure or extrusion and deep superior sulcus deformity were evaluated postoperatively. After a mean follow-up interval of 11.5 months for group 1 and 13.2 months for group 2, vertical measurements were approximately 20% less than horizontal measurements in both groups. The mean horizontal and vertical movements in group 2 were significantly less than in group 1 (p < 0.001). There was 1 case of small hydroxyapatite exposure in group 2 (1 in 50; 2%) and 2 cases of implant extrusion in group 1 (4%) (p = 0.50). Deep superior sulcus deformity was noted in 10 patients in group 1 (20%) and 7 patients in group 2 (14%) (p = 0.43). Analysis of covariance in both groups showed that age, gender, and follow-up interval were not predictors of movement in either direction (all p-values >0.05). Evisceration with scleral quadrisection and alloplatic sphere implantation can effectively substitute for a more extensive procedure such as enucleation in patients with painful blind eyes, cosmetically unacceptable blind eyes, and medically uncontrolled endophthalmitis. It provides rapidity, ease, and better implant excursion and lower cost of the implants compared with their porous counterparts.

Early Outcome of Spherical Ceramic Trapezial-Metacarpal Arthroplasty

A retrospective review of 50 ceramic, spherical implants for the treatment of trapezial-metacarpal osteoarthritis in 49 patients assessed clinical and radiographic outcome. Thirty-five patients returned for a clinical examination and completed an outcome survey at a mean follow-up of 3 years. A radiographic review was available for all 50 implants with a mean follow-up of 3 years. Average patient age at surgery was 59 years (35 women and 15 men). Twenty-five patients were retired and 24 were regularly employed preoperatively. Overall satisfaction was between "very satisfied" and "satisfied" for 32 patients, and none were dissatisfied. Twenty-nine patients rated both frequency and severity of pain as "less than before surgery" or "much less than before surgery." Average rating for thumb and hand strength was the "same as before surgery." Thumb pinch strength averaged 40 N (91% that of the opposite thumb). Postoperative thumb opposition was Kapandji stage 8 or better in 34 of 50 thumbs and stage 6 or better in patients who had an interphalangeal joint or metacarpophalangeal joint fusion. All 24 employed patients returned to work, but 2 required substantial modifications of pinch and grasp movements. Implant subsidence occurred in 47 of 50 thumbs, ranging from 1 to 13 mm. Trapezium fractures occurred in 15 thumbs. Eleven additional thumbs showed erosions and cystic changes within the trapezium or metacarpal. There was no evidence of arthritis developing in surrounding joints. In addition to adverse radiographic changes, there were 10 complications in 10 patients, including implant subluxation in 7 patients. Although most patients were satisfied with their function and pain relief, adverse radiographic findings were nearly universal. Implant subsidence, especially into the trapezium, was often severe, with some resulting in a trapezium fracture. Based on the radiographic outcome at this medium-term follow-up, we no longer use this implant. Therapeutic IV.

Reply re: “Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration”

Reply re: “Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration”

Re: “Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration”

Re: “Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration”

Re: “Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration”

Ophthalmic Plastic & Reconstructive Surgery: November 2007 - Volume 23 - Issue 6 - p 500-501 doi: 10.1097/IOP.0b013e31815a128f

Autologous dermis graft at the time of evisceration or enucleation

Aim:To present a new technique using autologous dermis graft at the time of enucleation or evisceration to replace the ocular surface area lost when the corneal scleral button is excised.Methods:A...

Artificial eye amplitudes and characteristics in enucleated socket with porous polyethylene spherical and quad-motility implant

To compare artificial eye amplitudes in enucleated socket with porous polyethylene either spherical or quad-motility implant and study the characteristics of artificial eyes fit with the two orbital implants. A total of 21 patients were prospectively studied who underwent enucleation because of an intraocular melanoma and the randomization defined a porous polyethylene either spherical or quad-motility orbital implant. Measurements of the amplitude of the artificial eye were obtained with prism and digital photos. The software Scion Image analyzed the digital photos (www.scioncorp.com) and the quantitative data were allocated to groups. The measurements (height, length, thickness) and weight of the 21 artificial eyes were analyzed. Student's t-test was performed to determine the significance of difference between groups (p<0.05). There was no statistically significant difference of the artificial eye amplitude analyzed by means of prisms between both orbital implants (p>0.05 for all directions). On analyzing the digital photos, the artificial eye with spherical implant showed higher artificial eye amplitude downward (p=0.009) among patients older than 55 years old, rightward (p=0.036) and downward (p=0.008) among the 9 patients with enucleated right eye. Height and length were similar in the 21 artificial eyes but those artificial eyes fit with quad-motility orbital implants were statistically significant thicker (p<0.001) and heavier (p=0.001). The similar amplitude of movement of artificial eyes was observed with both spherical and quad-motility orbital implants. Artificial eyes fit with quad-motility orbital implant are significantly thicker and heavier than those fit with spherical orbital implant.

Clonal Multipotency of Skeletal Muscle-Derived Stem Cells Between Mesodermal and Ectodermal Lineage

The differentiation potential of skeletal muscle-derived stem cells (MDSCs) after in vitro culture and in vivo transplantation has been extensively studied. However, the clonal multipotency of MDSCs has yet to be fully determined. Here, we show that single skeletal muscle-derived CD34-/CD45- (skeletal muscle-derived double negative [Sk-DN]) cells exhibit clonal multipotency that can give rise to myogenic, vasculogenic, and neural cell lineages after in vivo single cell-derived single sphere implantation and in vitro clonal single cell culture. Muscles from green fluorescent protein (GFP) transgenic mice were enzymatically dissociated and sorted based on CD34 and CD45. Sk-DN cells were clone-sorted into a 96-well plate and were cultured in collagen-based medium with basic fibroblast growth factor and epidermal growth factor for 14 days. Individual colony-forming units (CFUs) were then transplanted directly into severely damaged muscle together with 1 x 10(5) competitive carrier Sk-DN cells obtained from wild-type mice muscle expanded for 5 days under the same culture conditions using 35-mm culture dishes. Four weeks after transplantation, implanted GFP+ cells demonstrated differentiation into endothelial, vascular smooth muscle, skeletal muscle, and neural cell (Schwann cell) lineages. This multipotency was also confirmed by expression of mRNA markers for myogenic (MyoD, myf5), neural (Musashi-1, Nestin, neural cell adhesion molecule-1, peripheral myelin protein-22, Nucleostemin), and vascular (alpha-smooth muscle actin, smoothelin, vascular endothelial-cadherin, tyrosine kinase-endothelial) stem cells by clonal (single-cell derived) single-sphere reverse transcription-polymerase chain reaction. Approximately 70% of clonal CFUs exhibited expression of all three cell lineages. These findings support the notion that Sk-DN cells are a useful tool for damaged muscle-related tissue reconstitution by synchronized vasculogenesis, myogenesis, and neurogenesis.

Factors affecting orbital abnormal development and its relevant treatments

Orbital development is associated with the growth of the eyeball. During the development period, congenital or acquired changes of volume of the eyes and radiation treatment in ocular region influence the development of the orbit. Abnormal development of the orbit influences craniomaxillofacial growth and person's overall aesthetics of the face afterwards. Reconstruction of contracted sockets and shrunken orbits poses significant difficulties and obstacles that often results in universal frustration and disappointment results. Various methods have been used to improve these abnormalities. There are substantial different opinions regarding which method offers the best outcome. Traditional methods involve using progressively enlarging conformers, static spherical orbital implants, demis-fat grafts, and inflatable balloon expanders for orbital enlargement. Recently, the self-expander hydrogel tissue expander is available that expanders our option. This article reviews the influence of ocular abnormalities on the development of the orbit, as well as the advantages and disadvantages of various treatments for promoting the development of the orbit.

Amniotic membrane transplantation for porous sphere orbital implant exposure

This study is aimed at describing the clinical outcome of amniotic membrane transplantation for exposure of porous sphere implants. A retrospective review of consecutive cases of porous sphere orbital implant exposure was carried out. Eight cases were presented between May 2004 and Oct. 2006 (5 males, 3 females; mean age 44.5 years). Six had enucleation and two had evisceration. Exposure occurred in two primary and six secondary. Orbital implant diameter was 22 mm in seven cases and 20 mm in one case. Six patients are with hydroxyapatite and two with high-density porous polyethylene (Medpor) orbital implants. The mean time from implantation to exposure was 1.1 months (range 0.8-2 months). All patients required surgical intervention. The time of follow-up ranged from 3.0 to 28.0 months (mean 16.5 months). Amniotic membrane grafting successfully closed the defect without re-exposure in all of these patients. The grafts were left bare with a mean time to conjunctiva of about 1 month (range 0.8-1.5 months). Exposed porous sphere implants were treated successfully with amniotic membrane graft in all of patients. The graft is easy to harvest. This technique is useful, dose not lead to prolonged socket inflammation and infection, and it is valuable application extensively.

Long-term Follow-up of Porous Polyethylene Spherical Implants After Enucleation and Evisceration

To present long-term follow-up data on enucleations and eviscerations carried out with placement of spherical porous polyethylene implants. A retrospective, interventional, noncomparative case series of all patients undergoing primary evisceration or enucleation surgery from one teaching hospital ophthalmology department. In total, 106 cases were identified. Eighty patients (75.5%) underwent enucleation (group A) and 26 (24.5%) underwent evisceration (group B). Patient demographics were similar in both groups. Mean implant size in group A was 20.5 mm and 17.2 mm in group B. Mean follow-up in group A was 40 months (range, 12 to 80 months). Mean follow-up in group B was 63 months (range, 12 to 72 months). Six cases (7.5%) in group A had complications (excluding implant exposure), whereas one case (3.8%) in group B had a complication (excluding implant exposure). Five patients (6.3%) in group A had implant exposure; 14 cases (53.8%) of implant exposure occurred in group B. Our case series revealed a significantly higher incidence of implant exposure after evisceration than after enucleation. Our data suggest that enucleation should be the procedure of choice when removing an eye to minimize the risk of subsequent complications, particularly orbital implant exposure.

Hydroxypropyl Methylcellulose (HPMC) Lubricant Facilitates Insertion of Porous Spherical Orbital Implants

The insertion of an orbital implant in the posterior Tenon's space or in the eviscerated sclera must be smooth, without entrapment or dragging of adjacent soft tissue. Anterior Tenon's fascia and conjunctiva must be closed without undue tension that could lead to subsequent postoperative implant exposure. Current methods to prevent tissue drag include passing the implant via a cut "thumb" from a surgeon's glove, the use of a prepackaged rigid plastic funnel, or a specialized orbital implant introducing forceps, e.g., Carter sphere injector. We recommend also coating the porous implant with an inert semisynthetic viscoelastic polymer, thus enabling easy placement. We illustrate this in a typical case.

Use of self-expanding, hydrophilic osmotic expanders (hydrogel) in the reconstruction of congenital clinical anophthalmos

Rehabilitation of the congenitally anophthalmic orbit is frustrating to both the parents and physician. Traditional methods involve using progressively enlarging static acrylic conformers to expand the conjunctival socket, followed by placement of conventional static spherical orbital implants, dermis-fat grafts, or inflatable balloon expanders for orbital enlargement. Limitations of these methods typically result in less-than-optimal cosmetic outcomes, with retardation of bony orbital and overlying soft tissue growth adversely affecting midfacial growth and symmetry. Recent advances in tissue expansion technology may offer additional, novel alternatives to conventional therapies. Hydrogel tissue expanders were recently adapted for use in congenital anophthalmia. The expanders are placed in their dry, contracted states, and expand gradually to their full size via osmosis of surrounding tissue fluid, with up to a 10-fold increase in volume. Offering the benefit of predictable and controllable self-expansion, hydrogel expanders may offer yet another alternative or adjunctive therapy to the early rehabilitation of the contracted socket. Separate appliances are used for conjunctival and orbital reconstruction. Initial results appear promising. Tempering the enthusiasm for their use, however-particularly in terms of implanted orbital expanders-is the recent spate of long-term complications reported from previous uses of hydrogels as scleral buckling material. Self-expanding hydrogel tissue expanders appear to offer an intriguing reconstructive alternative to the frustrating condition of congenital anophthalmia. Long-term safety of the material as an orbital implant has not yet been demonstrated, but early results are promising.

Safety of unwrapped spherical orbital implants.

To determine the exposure rate of unwrapped spherical orbital implants after enucleation surgery. Retrospective review of consecutive case series. All patients undergoing orbital implantation during enucleation surgery from October 1999 to September 2003 were included. Charts were reviewed for preoperative diagnoses, type and size of implant, use of a wrapping material, and complications. Twenty-six consecutive patients underwent enucleation surgery without wrapping material. Nineteen patients received porous polyethylene, 5 patients received polymethylmethacrylate, and 2 received hydroxyapatite. Mean implant diameter was 21.03 mm. Mean follow-up was 17.1 months (range, 2 to 43 months). There were no complications of implant extrusion, exposure, infection, or migration. The use of unwrapped spherical orbital implants may be associated with a low rate of early exposure. Careful choice of implant type may help reduce the risk of implant exposure.

Finish diamond machining of ceramic femoral heads

In the present paper reported is the manufacturing of ceramic spherical implants for medical purposes by employing diamond-abrasive lapping techniques. The technological parameters of this technique and a theoretical model experimentally verified are presented. A novel method of control of the free lapping process is suggested, resulting, as indicated by the experimental and theoretical results, in a decrease of time requested for the coordination of the profiles of the tool and the workpiece and in an increase of the process efficiency when manufacturing precision work surfaces.

Hydroxyapatite and calcium phophate coatings on aluminium oxide orbital implants

Background: Hydroxyapatite and calcium phosphate have been used as bone graft substitutes as they facilitate and promote tissue ingrowth. We carried out a study to examine uncoated and coated aluminium oxide (alumina) spherical orbital implants and assess whether the coatings influence fibrovascular ingrowth.Methods: The aluminium oxide spheres (three coated with hydroxyapatite, three coated with calcium metaphosphate and three uncoated) were manufactured at the School of Materials Engineering, Yeungnam University, Kyongsan, Kyongbuk, Korea. The implants were examined macroscopically and with scanning electron microscopy and were analysed chemically by means of x-ray powder diffraction and x-ray fluorescence spectrophotometry. Implantation of three hydroxyapatite-coated, three calcium metaphosphate-coated and three uncoated aluminium oxide spheres was done in nine adult male New Zealand albino rabbits. Implant vascularization was evaluated at 4, 8 and 12 weeks by means of histopathological sectioning.Results: All three types of implant had multiple interconnected pores. The coatings increased the size of the trabeculae from 150 μm to 300 μm. As a result, the pores appeared slightly smaller but still ranged in size from 300 μm to 750 μm, compared to 400 μm to 800 μm in the uncoated implants. The coatings also increased the weight of the implants slightly. The implants were all strong mechanically. They were made up primarily of aluminium oxide. The coated implants contained significant amounts of calcium oxide (a contaminant). There was no clinical difference in the socket response between the three groups. Histopathologically, fibrovascularization occurred uniformly throughout each implant at 4, 8 and 12 weeks after implantation.Interpretation: The hydroxyapatite and calcium metaphosphate coatings did not appear to facilitate or inhibit fibrovascular ingrowth at 4, 8 and 12 weeks. Longer-term studies are need to determine whether the coatings play a role in long-term acceptance and retention of the implants.

Capsular calcification of alloplastic orbital implants

PURPOSE: To report calcification of the capsule surrounding alloplastic orbital implants and postulate this calcification as a possible cause of poor implant motility.DESIGN: Interventional case reports.METHODS: Two patients with alloplastic spherical implants after enucleation presented with poor implant motility. Both patients underwent orbital implant exchange with a quasi-integrated porous polyethylene orbital implant.RESULTS: During removal of the original alloplastic orbital implant, a hard, thick shell adherent to the surrounding orbital tissues was encountered. After complete excision of the shell, microscopic evaluation confirmed a dense, fibrous capsule with calcification. No evidence of inflammation or malignancy was associated with either capsule. Postoperatively, both patients had significant improvement in motility of their new orbital implant.CONCLUSIONS: Although calcification of the fibrous capsule surrounding alloplastic orbital implants is an unusual finding, it may result in poor implant motility. Capsule excision and implant exchange may significantly improve the motility of the orbital implant.

Surgical Management of the Anophthalmic Orbit, Part 1: Congenital

Congenital microphthalmos and anophthalmos are rare conditions in which orbital growth is deficient. Hypoplasia of the globe affects the bony orbit (micro-orbitism), the conjunctival sac, and eyelids (microblepharism), and it may be associated with abnormalities of the entire hemifacial skeleton (hemifacial microsomia). In the present article, the authors review a series of 19 patients with microphthalmos (nine had right-sided, one had bilateral, and nine had left-sided microphthalmos) who were treated in the Orbitopalpebral Unit at Hospital Foch over a period of 15 years (follow-up, 5 months to 18 years).Orbital expansion was achieved using spherical implants (n = 13), orbital osteotomies (n = 4), and orbital expanders (n = 2). Both expanders were removed within 6 months because of failure (one infection and one rupture). The current preferred method for orbital expansion is to use serial implants in the growing orbit and osteotomies in cases of late referral or insufficient orbital volume in the older child. The target proportions of the reconstructed orbit are not planned to mirror the healthy side exactly. The inferior orbital rim is kept higher to support the orbital implant, and the orbit is kept shallow to avoid a sunken appearance. Cranial bone grafts were used to augment deficient orbital contours; they were assisted by anterior transposition of the temporalis muscle (n = 5) when additional orbital volume was required. Conjunctival sac reconstruction was achieved by the use of serial conformers placed in the conjunctival sac during the neonatal period, followed by grafts of buccal mucosa and full-thickness skin maintained in place with a tarsorrhaphy for 3 to 6 months. Eyelid reconstruction using local flaps and skin grafts proved to be necessary in cases treated by osteotomy expansion, although reconstruction was not required after expansion using serial solid shapes. The results illustrate an evolution in approach and concepts of reconstruction of the microphthalmic orbit and emphasize the need for an integrated craniofacial approach for this complex deformity.

2-Octyl Cyanoacrylate Tissue Adhesive and Muscle Attachment to Porous Anophthalmic Orbital Implants

To investigate the tolerance and efficacy of a topical bioadhesive for direct muscle attachment to porous orbital motility implants. Ten New Zealand White rabbits underwent unilateral enucleation with unwrapped 12-mm spherical porous implants placed into the muscle cone. Four animals received porous polyethylene implants and 6 received bone-derived hydroxyapatite implants. Small amounts of a bioadhesive (2-octyl cyanoacrylate) were applied to the underside of the muscles. Muscles were placed onto the desired location of the implant with pressure for 15 seconds. The conjunctiva was closed with a 6-0 plain gut suture, and the animals were observed for 6 weeks. At 6 weeks, animals were killed and the surgical orbit was exenterated. Orbits and implants were processed for histologic analysis. In addition, tensile strength testing of muscle-implant attachments was performed and compared with various other types of muscle-implant or muscle-sclera attachments. All cases resulted in integration of the muscles without slippage. All unwrapped hydroxyapatite implants (n = 6/6) had small anterior implant exposures without infection, significant inflammation, or exposure. No exposures were noted in porous polyethylene implants (n = 0/4). All implants were filled with fibrovascular tissue by 6 weeks. 2-Octyl cyanoacrylate yielded tensile strengths similar to that of sutured muscle coupling. 2-Octyl cyanoacrylate is well tolerated in the orbit, inducing minimal inflammation. It effectively attaches muscles to porous implants without hindering permanent integration or vascularization. The exposure rate for unwrapped hydroxyapatite spheres was not caused by the adhesive, as evidenced by the lack of exposures in the porous polyethylene implant group. 2-Octyl cyanoacrylate may be effective in reducing the cost and time for enucleation surgeries when porous motility implants are used.

Comparison of artificial eye amplitudes with acrylic and hydroxyapatite spherical enucleation implants

Purpose To compare artificial eye amplitudes in patients who randomly received either a hydroxyapatite or an acrylic, scleral-covered spherical implant after enucleation. Design Randomized, controlled trial. Participants Thirty-four consecutive patients who underwent enucleation because of an intraocular melanoma and 21 healthy control participants from the hospital staff. Methods Eligible patients randomly received a hydroxyapatite or an acrylic, scleral-covered spherical orbital implant. Fourteen patients were fitted with a hydroxyapatite implant, and 16 were fitted with an acrylic implant. We measured horizontal and vertical saccadic amplitudes of both the artificial eye and the healthy eye. Measurements were performed with the magnetic search coils technique. Saccadic amplitudes of the artificial eye were compared with the healthy eye of the patient. The amplitudes of the healthy eyes were compared with saccadic amplitudes of control participants. The interval from surgery to measurements was at least 3 months in all patients. Saccadic gain (artificial eye and eye amplitude divided by target amplitude) and saccadic symmetry (artificial eye amplitude divided by healthy eye amplitude) were calculated. Main outcome measures Saccadic gain and saccadic symmetry. Results The gain in the healthy eyes of the patients was comparable with the gain of the control eyes. Saccadic symmetry was 1.0 in control participants. In patients, it was 0.334 in horizontal saccades and 0.577 in vertical saccades. However, saccadic symmetry did not differ significantly between the acrylic group and the hydroxyapatite group ( P > 0.1 for any saccadic direction). Equivalence was detectable with a power more than 90% for horizontal saccades and more than 80% for vertical saccades. Curvilinearity was rejected for both patient groups and for all saccadic directions ( P > 0.5). Conclusions When no motility peg is placed, acrylic and hydroxyapatite spherical implants yield comparable saccadic amplitudes of the artificial eye. Artificial eye amplitudes were markedly more restricted horizontally than vertically. In all saccadic directions, the relation between target amplitude and artificial eye amplitude was linear.