Customized orbital implant versus 3D preformed titanium mesh for orbital fracture repair: A retrospective comparative analysis of orbital reconstruction accuracy

This study aimed to compare the accuracy of inferomedial orbital fracture restoration using customized orbital implant versus 3D preformed titanium mesh. Patients were divided into two groups. Group 1 underwent surgery with customized orbital implants and intraoperative navigation, while group 2 was treated using 3D preformed titanium meshes with preoperative virtual surgical planning (VSP) and intraoperative navigation. Reconstruction accuracy was assessed by: (1) comparing the postoperative reconstruction mesh position with the preoperative VSP; and (2) measuring the difference between the reconstructed and unaffected orbital volume. Pre- and postoperative diplopia and enophthalmos were also evaluated. Fifty-two patients were enrolled (25 in group 1 vs 27 in group 2). The mean difference between final plate position and ideal digital plan was 0.62 mm (SD = 0.235) in group 1 and 0.69 mm (SD = 0.246) in group 2, with no statistical difference between the groups (p = 0.282). The mean volume differences between the reconstructed and unaffected orbits were 0.95 ml and 1.02 ml in group 1 and group 2, respectively, with no significant difference between the groups (p = 0.860). Overall clinical improvements, as well as complications, were similar. 3D preformed titanium meshes can reconstruct inferomedial fractures with the same accuracy as customized implants. Therefore, in clinical practice, it is recommended to use 3D preformed meshes for this type of fracture due to their excellent results and the potential for reducing time and costs.

Outcomes of planned versus emergent enucleation procedures with primary orbital implants

OBJECTIVE

The primary purpose of this study was to explore the outcomes of primary implant placement in patients who have undergone enucleation on either a planned or emergent basis.

METHODS

A retrospective chart review was performed of 128 enucleations with at least a 1-year postoperative follow-up between November 2008 and May 2019 by a single oculoplastic surgeon at Albany Medical Center. Emergent cases were categorized as those with an active, unclosed globe perforation, secondary to either acute trauma, dehiscence or failed closure of a previously opposed wound, or exposure of a surgical site with dehiscence of the underlying sclera. Patient demographics, clinical features, and postoperative findings were recorded. The incidence of implant exposure was used as an indication of patient outcomes, and the data were subsequently analyzed using t tests.

RESULTS

Of the 128 enucleations performed, 32 (25%) were carried out on an emergent basis, of which 2 patients (6.25%) developed implant exposure. In contrast, of the 96 enucleations that were carried out in a planned, nonemergent manner, 3 patients (3.1%) developed implant exposure. There was no significant relationship between implant exposure rates in the acute and planned enucleation groups (p = 0.4047).

CONCLUSIONS

Despite the implications of globe perforation, our analysis suggests no significant correlation of implant exposures in acute versus planned enucleations with primary orbital implants. As such, physicians may confidently place a primary implant at the time of enucleation in both groups, and they may use these data to counsel their patients about the risks of postoperative complications.

Surgical outcomes of unwrapped acrylic orbital implants: A review of 192 patients

PURPOSE

The purpose of this study is to report the results in a series of acrylic orbital implant placements without the use of wrapping material.

METHODS

We retrospectively reviewed the records of the patients who underwent enucleation with acrylic orbital implant insertion without scleral wrapping at the Department of Ophthalmology, Poznań University of Medical Sciences, Poland, between 2013 and 2020.

RESULTS

There were 192 patients: 102 women and 90 men, mean age: 60 years (range: 13-90 years). In the majority of cases, the reason for enucleation was uveal melanoma (148 patients-77.1%), followed by secondary glaucoma in 22 patients (11.5%) and painful, phthisical eye in 16 (8.3%). The median follow-up was 23 months (range: 1-96 months). The stability of the implants was satisfactory in the majority of cases, and there were no cases of implant migration identified during the study period. We noted a total of 4 (2%) implant exposures. Other postoperative complaints included eyelid malposition-21 patients (11%), Tenon's capsule thinning (15 patients-7.8%) and post-enucleation eye socket syndrome (PEES)-7 patients (3.6%). The rate of postoperative complications was associated only with a history of previous ocular surgery (P=0.006).

CONCLUSIONS

The stability and functional outcomes of unwrapped acrylic orbital implants in this group of patients were satisfactory during the follow-up period.

Silicone Sphere Implant Extrusion From Orbital Granulomatosis With Polyangiitis: A Rare Complication in the Anophthalmic Socket

Orbital implant extrusion is a known complication following evisceration and enucleation. In this case report, we present a 45-year-old woman who presented with a left silicone implant exposure and infection 2 years following evisceration with saddle nose on examination. CT of the maxillofacial bones without contrast showed bilateral soft tissue infiltration around the superior recti muscles, as well as a nasal septum perforation from extensive sinus disease. Left orbitotomy revealed a small fibrotic mass near the orbital roof. Biopsy and serology results were consistent with granulomatosis with polyangiitis.

Bioresorbable Implants in Reduction of Paediatric Zygomaticomaxillary Complex Fractures Concurrent With Internal Orbital Reconstruction

PURPOSE

To evaluate the clinical effectiveness and safety of bioresorbable implants for treating paediatric zygomaticomaxillary complex (ZMC) fractures with concomitant orbital floor defects.

METHODS

A retrospective review of paediatric patients who underwent ZMC repair with concomitant orbital floor fractures with bioresorbable implants in Shanghai Ninth People's Hospital from July 2015 to June 2019 was performed. The primary outcome measures included ocular motility, diplopia, enophthalmos, facial deformities, and restricted mouth opening, as well as complication rates. Pre- and post-operative computed tomography scans were obtained for clinical diagnosis and surgical effectiveness.

RESULTS

Twenty two children were included in this study. Facial deformities were corrected in all 22 cases by surgical reconstruction postoperatively, and the average relative distance of Portals point-Zygomaxillare and Anteriornasalspine-Zygomaxillare were 1.3 ± 0.6mm ( P = 0.22) and 1.2 ± 0.5mm ( P = 0.19). The eye movement restored to normal in 13 patients. The mean amount of relative enophthalmos was 1.0 ± 0.4 mm ( P = 0.12). 12 cases had complete resolution of diplopia postoperatively at the extremes of the gaze, and 1 case presented persistent diplopia on the down gaze as before, but from level III to level I. Facial numbness was resolved completely in 6 cases, and 2 cases presented with persistent numbness but relieved significantly. The average Hounsfield units of RapidSorb plates and OrbFloor PI were 154 ± 5 and 99 ± 4 respectively on computed tomography image obtained 1 week postoperatively, which showed no obvious difference compared with 0.5 year postoperatively ( P > 0.1). Hounsfield units of implants gradually declined around 1 year postoperatively. Hounsfield units of RapidSorb plates (20 ± 1) were consistent with periorbital tissue during postoperative 2-year follow-up, and Hounsfield units of OrbFloor PI (19 ± 1) were consistent with periorbital tissue during postoperative 1.5-year follow-up. No patients had severe sequelae or implant related complications postoperatively. None of bone nonunion, malunion, infection or rejection occurred during the follow-up periods.

CONCLUSIONS

Open reduction and internal fixation for the treatment of ZMC fracture have achieved significant improvement in functional and cosmetic outcomes postoperatively. Bioresorbable materials have been proved to be effective and safe in the treatment of children's ZMC and orbital wall fractures.

Patient-specific Implants for Orbital Fractures: A Systematic Review

PURPOSE

Orbital fractures are common facial fractures that can be challenging to repair and require careful attention to avoid unacceptable ophthalmic complications. Customized implants that are unique to an individual patient, or patient-specific implants (PSIs), have been increasingly used to repair orbital wall fractures. This systematic review summarizes the current evidence regarding custom-made orbital wall implants.

METHODS

A keyword search of published literature from January 2010 to September 2021 was performed using Ovid MEDLINE, PubMed, and the Cochrane Library databases. Original articles that included more than 3 human subjects with an orbital fracture repaired with a PSI were included. The search results were reviewed, duplicates were removed and relevant articles were included for analysis.

RESULTS

Fifteen articles meeting the inclusion criteria. The articles were categorized into 3 separate groups based on the method of PSI fabrication: manual molding of a PSI on a 3D-printed orbital model (53%), directly from a 3D printer (27%), or via a template fabricated from a 3D printer (20%). Three primary postoperative outcomes were assessed: rates of diplopia, enophthalmos, and orbital volume. Postoperative rates of diplopia and enophthalmos improved regardless of the PSI technique, and postoperative orbital volumes were reduced compared with their preoperative state. When PSIs were compared to conventional implants, patient outcomes were comparable.

CONCLUSIONS

This review of existing PSI orbital implant literature highlights that while PSI can accurately and safely repair orbital fractures, patient outcomes are largely comparable to orbital fractures repaired by conventional methods, and PSI do not offer a definitive benefit over conventional implants.

Two-Stage Procedure for Management of Large Exposure Defects of Hydroxyapatite Orbital Implant

PURPOSE

To report the results of a newly devised two-stage surgical technique for management of large hydroxyapatite exposure defects.

METHODS

Eight patients with exposed hydroxyapatite orbital implant were treated in two stages. The exposed hydroxyapatite anterior surface was burred down and the defect was directly closed 3 to 13 months after the primary procedure. Then a mucous membrane or dermis-fat graft was added for socket reconstruction.

RESULTS

Trauma was the primary cause of enucleation in all patients. Hydroxyapatite exposures occurred 1 to 2 weeks after implantation. Mean defect size was 15 mm in the greatest dimension (range 10-21 mm). Socket reconstruction was done in seven patients with mucous membrane graft and in one patient with dermis fat graft 3 to 13 months after direct repair of the defects. All eight patients maintained closure of the defects during a mean follow-up of 13 months (range 9-19 months).

CONCLUSIONS

Management of hydroxyapatite exposures, especially those with large defects, can be difficult. Based on our experience, optimal results can be obtained after direct closure of the defect under minimal tension at the expense of foreshortening the fornices after which the socket can be reconstructed with a mucous membrane or dermis fat graft as a secondary procedure.

[Tolerance of porous polyethylene orbital implants in children]

INTRODUCTION

The purpose of our study is to determine the incidence of orbital complications that occurred after insertion of orbital porous polyethylene implant in children under the age of 15 years.

MATERIAL AND METHODS

We report a series of 21 eyes of 21 patients younger than 15 years and in which a porous polyethylene implant is used for reconstruction of the orbital cavity after enucleation between January 2003 and December 2008.All patients were operated on by the same surgeon using the same technique.

RESULTS

These 11 boys and 10 girls, whose average age is 5.7 years. Histopathologic diagnoses after enucleation are dominated by the retinoblastoma (10 eyes) and phthisis bulbi (6 eyes). After a mean follow up of 23 months it was observed two cases of implant extrusion in children enucleated for retinoblastoma. No cases of orbital cellulitis or enucleated syndrome have been reported.

DISCUSSION

The most common complication of porous polyethylene implants in children is exposure. Risk factors may be related to surgical technique, infection, the implant, use of wrapping material and the association with adjuvant chemotherapy. Using a porous polyethylene implant uncovered remains an appropriate technique in children under 15 years for the reconstruction of the anophthalmic cavity, provided a rigorous surgical technique.

Cyst formation associated with porous polyethylene orbital floor implant

A 28-year-old female presented with hyperglobus and inferior scleral show after the repair of an orbital floor fracture using a porous polyethylene (Medpor) implant. CT revealed a large inferior orbital cystic mass displacing the globe. The cyst was explored and excised and the implant was found to be free from any attachment to surrounding tissues and hence, removed without difficulty. The reason for the cyst development was most likely inadvertent epithelial inclusion at the time of surgery-a recognized risk with insertion of any foreign body via transconjunctival approach. Porous implants when placed in the subperiosteal space might not get incorporated with surrounding tissues and therefore behave like any traditional nonporous alloplastic material.

Aspergillus infection of supramid orbital implant and hyperostosis of orbital bone: report of a unique case

PURPOSE

The authors report the clinical findings in a patient who developed proptosis fourteen years after an orbital floor fracture repair with a Supramid orbital implant due to hyperostosis of the orbital floor and lateral orbital wall bone secondary to aspergillus infection.

METHODS

Clinical, radiological, microbiological and histological findings and the management of this patient are presented.

RESULTS

A 25-year-old male was referred with proptosis and lower lid retraction, fourteen years after a traumatic orbital floor fracture repair with a Supramid implant. Orbital exploration revealed a thick irregular sheet of bone covering the orbital floor implant and extending laterally along the lateral orbital wall. Aspergillus fumigatus was grown from the Supramid implant as well as from the bone and histology showed chronic inflammatory process with reactive bone formation. Patient was treated with a course of oral Voriconazole and post-operatively the patient is asymptomatic with reduction in proptosis.

CONCLUSION

To the best of our knowledge, this is the first case of Apergillus fumigatus infection secondary to a Supramid orbital floor implant, associated with hyperostosis of orbital bone.

[The embedded mobile orbital implant from methylmethacrylate "Hydron"--clinical and histopathological findings 25 years after implantation]

The embedded mobile hydrogel methylmethacrylate ("HYDRON" Spofa) orbital implants introduced in the beginning of 70th years of 20th century was a new method to get good cosmetic effects after enucleation. At the Dept. of Ophthalmology of the Comenius University, Bratislava, the rejection rate of this type of orbital implants in the first years after enucleation (1971-1974) was only 16.8%. This technique was applied in patients after enucleation due to traumatic phtisis of the eye globe. Authors submit a case report of a female patient from the group of implanted mobile orbital implant HYDRON implanted in 1984. They analyze clinical features and histopathological findings after surgical removement 25 years after implantation.

[A case of inadequate surgery tactics in the use of an unstandard orbital implant]

By analyzing a clinical case with inadequate surgery tactics in the use of an unstandard orbital implant, the authors discuss possible errors in surgical techniques and in the choice of an implant. Furthermore, by analyzing problems in the use of various implants, including those unstandard ones, they discuss possible causes of complications, consider the optimal time for resurgeries, and propose the ways of solving the problems associated with the occurrence of complications, including treatment policy.

[Effects of placement of orbital implant on orbital osteocytes]

OBJECTIVE

To investigate the influence of enucleation with or without orbital implant on the occurrence of apoptosis of orbital osteocytes and to explore the mechanism of orbital implant in the prevention and treatment of orbital malformations.

METHODS

It was an experimental research. Twenty-one age and weight-matched New Zealand rabbits were divided into three groups: enucleation group, enucleation with implant group and the control group. At one-month-old, the left eyes of the rabbits were enucleated in the enucleation group; an orbital implant was inserted after enucleation in the implant group. The left orbits of rabbits in the control group were served as the controls. At two-month-old, all rabbits were sacrificed, apoptosis of osteocytes of the zygomatic bones was observed by photomicroscopy, electron microscopy and TUNEL staining technology. The ratios of apoptosis osteocytes were calculated and analyzed in these three groups.

RESULTS

Classical apoptosis of osteocytes was found with photomicroscopy and electron microscopy. The distribution of apoptosis of osteocytes was irregular in bone sections. The ratio of apoptosis cells in the enucleation group was significantly different from that in the other two groups (P<0.01). There was no significant difference in ratios of apoptosis cells between the implant group and the controls (P>0.05).

CONCLUSIONS

Apoptosis of osteocytes participates in the normal development of bony orbit. The results of this study indicate that apoptosis of osteocytes plays a role in the development of orbital malformation after enucleation and orbital implant can prevent the orbital malformation after enucleation.

A case of chronic infection 28 years after silicone orbital implant

Silicone was one of the most common biocompatible materials used for orbital floor reconstruction about twenty to thirty years ago. Recently, surgeons hardly use silicone due to numerous reports of complications such as infection, extrusion and implant displacement. We present a case of chronic infection seen after 28 years of silicone implant used in orbital floor repair. Although it is reported that infection due to silicone implant may decrease after long years of follow up, our case demonstrated the possible case of unexpected infection after more than twenty years with orbital silicone implant.

[Use of Medpor spherical implant: analysis of 61 orbital surgeries]

PURPOSE

To analyze the use of Medpor biointegrated implant in surgeries of evisceration, enucleation or secondary implantation in anophthalmic sockets.

METHODS

The Medpor orbitary implant was used in 61 surgeries. In 18 cases of evisceration the implant's wrapping was not necessary. In 12 enucleation and secondary implantation surgeries the utilized material to wrap the implant was homologous duramater. In the other 31 surgeries, the implant wrapping was made from autologous tissue (sclera, dermis, orbicular muscle or auricular cartilage), utilizing the "cap" technique--covering only the anterior surface of Medpor.

RESULTS

The patients were operated from January 1998 to December 2004 with an average follow-up period of 30 months. In all cases the implant was well accepted, allowing for a good adaptation of the prosthesis. Late exposure of the implant occurred in two patients: the first was corrected by the replacement of the implant in the cavity, while in the second case the exposure was wrapped with a tarsus flap.

CONCLUSIONS

In our experience the Medpor implant presents good acceptance, with a small exposure rate (only 2 cases), no infection or migration cases, and a good prosthesis adaptation in all patients. The use of autologous tissue to wrap the implant's anterior surface eliminates the inherent risk of using homologous tissues.

Abscessed porous polyethylene (Medpor) orbital implant: a case report

We report the evolution of clinical features of orbital implant infection in a 42-year-old man. Despite appropriate treatment recurrent conjunctival dehiscence could not be prevented. Explanation of the implant resulted in complete resolution of symptoms. Histopathological examination confirmed focal necrotising acute inflammation with the presence of colonies of the organism in the deep substance of the implant.

Delayed complications of silicone implants used in orbital fracture repairs

PURPOSE

To report a series of patients who developed late complications secondary to silicone implants used in orbital fracture repairs and review the literature.

DESIGN

Retrospective interventional case series.

METHODS

Analysis of records of patients who developed complications following repair of orbital wall fractures with silicone implants.

RESULTS

Over a 5-year period, 4 patients were seen with complications arising from a silicone orbital implant. There were 3 males and 1 female whose ages ranged from 41-73 years. The time interval between initial insertion of implant and development of complications was 1.5, 6, 10, and 20 years. The complications noted were worsening diplopia, recurrent orbital cellulitis, lower lid retraction with restricted upgaze, and orbital abscess. Computed tomographic scans demonstrated the implant in all cases. Histologic examination revealed nonspecific chronic inflammation and fibrosis in all cases and foci of squamous epithelium in one case. Treatment included surgical removal of the implant, resulting in complete resolution or significant improvement in symptoms and signs in all cases.

CONCLUSION

The use of silicone implants is associated with a wide range of complications, which may occur many years following the original surgery. Surgical removal of the implant usually leads to resolution of symptoms. Given the potential of silicone implants to cause delayed complications, their use in orbital fracture repair is not recommended.

Chronic orbital infection caused by migration of an orbital Silastic implant

A Silastic sheet was used for the repair of a lateral orbital wall defect in a 48-year-old man. Migration of this implant through the defect has caused recurrent episodes of orbital infection. Although migration of Silastic within the orbit has been reported previously, the absence of fixation together with further remodelling of the lateral orbital wall defect contributed to this phenomenon.

An Infected Porous Polyethylene Orbital Implant

A 75-year-old man underwent enucleation with placement of a porous polyethylene orbital implant (Medpor, Porex Technologies, Fairburn, GA, U.S.A.). Over the next 5 years, he was seen on numerous occasions with socket discharge that was unresponsive to a variety of eyedrops. Exposure and re-exposure of the implant occurred, and the implant was removed. Histopathologic assessment was consistent with an infectious process within the implant. Postoperatively, the patient's symptoms and signs resolved. Porous orbital implant infection is rare. The diagnosis may be delayed as the initial symptoms and signs (discharge, conjunctival inflammation) may easily be attributed to prosthesis wear. With time, and persistence of the symptoms despite numerous treatments, infection should be suspected.

Hyperostosis in an orbital defect with craniofacial implants and open-field magnets: a clinical report

An orbital facial prosthesis wearer was found to have significant hyperostosis in an exenterated orbit exposed to long-term, open field, rare earth magnets attached to craniofacial implants. Localized exophytic osseous formation was found in multiple areas around the exenterated orbit. The overall thickness of the walls of the exenterated orbit was approximately double that of the unaffected side. Magnetic field effect on bone formation and recommended treatment are discussed.

Complications of Pegged and Non-Pegged Hydroxyapatite Orbital Implants

PURPOSE

The purpose of this study is twofold: to assess the incidence and implications of complications unique to placing a freestanding polycarbonate peg in patients with hydroxyapatite implants and to compare the incidence of complications in these patients with the incidence in patients with non-pegged hydroxyapatite implants.

METHODS

This is a retrospective clinical case series of 103 patients who underwent hydroxyapatite implant insertion at our institution. The incidence of postoperative complications in patients who underwent freestanding polycarbonate pegging procedures (n = 21) and those who had not (n = 82) were compared.

RESULTS

One postoperative complication - infection - occurred in a significantly higher percentage of patients in the pegged group (42.9%, 9/21) compared with the non-pegged group (19.5%, 16/82), (p = 0.037). Fifteen of the 21 patients (71.4%) in the pegged group experienced complications unique to freestanding polycarbonate pegging. Overall, 95.2% (20/21) of patients in the pegged group experienced a complication compared with 58.5% (48/82) of patients in the non-pegged group, (p = 0.001). In addition, there was an average of 3.1 (66/21) complications per patient in the pegged group compared with an average of 1.9 (106/82) complications per patient in the non-pegged group (p = 0.010).

CONCLUSIONS

Patients who received a freestanding polycarbonate pegged implant had a high risk of experiencing complications unique to pegging, and therefore a significantly higher rate of complications overall when compared with patients whose implant was not pegged. In addition, patients who received a pegged implant had a higher incidence of infection. However, most patients retained their pegs despite complications.

Complications of primary placement of motility post in porous polyethylene implants during enucleation

PURPOSE

To evaluate the complications associated with the primary placement of a motility coupling post (MCP) in spherical porous polyethylene (PP) implants at the time of enucleation.

DESIGN

Retrospective, interventional case series.

METHODS

The records of all patients who had undergone primary enucleation and spherical PP implant with MCP insertion, and who were followed for at least six months were reviewed. The MCP was screwed to a wrapped implant to protrude 3 mm to 4 mm anteriorly. After placing the implant into the orbit, the extraocular muscles were sutured to the implant, and the Tenon capsule and conjunctiva were closed onto the MCP. When the MCP was not exposed spontaneously within two months after surgery, it was externalized with a conjunctival cut-down procedure.

RESULTS

The study included 52 patients (29 male, 23 female; age range, three to 76 years). The MCP became exposed spontaneously in 10 patients (19%). In the early postoperative period, we recorded nine complications in seven patients (13%), which might be related to primary MCP placement. These included prominent MCP decentration associated with implant motility restriction (6%), preseptal cellulitis (4%), and conjunctival prolapsus (8%). An ocular prosthesis was fit successfully onto the MCP in 51 patients. During the late period, 22 complications occurred in 15 patients (29%), including excessive discharge (15%), MCP decentration (4%), implant exposure (6%), implant infection (2%), pyogenic granuloma (8%), conjunctival overgrowth over the MCP (2%), conjunctival discoloration (4%), and lax eyelid syndrome (2%). Mean follow-up time was 34 months (range, six to 68 months).

CONCLUSIONS

Although MCP placement in the spherical PP implant during enucleation is a useful technique, it may be associated with complications such as MCP decentration, excessive discharge, exposure, and infection of the implant.

Culture-proven Aspergillus fumigatus infection in a primary hydroxyapatite orbital implant

Hydroxyapatite orbital implants are widely used in enucleation surgery. Infection in this setting is an uncommon but severe complication. Herein a patient with a 3-year history of chronic socket discharge, orbital discomfort, conjunctival breakdown and implant exposure after enucleation and implantation of a hydroxyapatite sphere 7 years previously is reported. Repeated attempts at covering the exposed implant failed. Eventually the implant was removed, and Aspergillus fumigatus was cultured from the explanted material. This is the second reported case of Aspergillus infection of a hydroxyapatite orbital implant, and the first case where fungal cultures were positive.

A case of orbital abscess following porous orbital implant infection

Purpose

We present a case of orbital abscess following porous orbital implant infection in a 73-year-old woman with rheumatoid arthritis.

Methods

Just one month after a seemingly uncomplicated enucleation and porous polyethylene (Medpor®) orbital implant surgery, implant exposure developed with profuse pus discharge. The patient was unresponsive to implant removal and MRI confirmed the presence of an orbital pus pocket. Despite extirpation of the four rectus muscles, inflammatory granulation debridement and abscess drainage, another new pus pocket developed.

Results

After partial orbital exenteration, the wound finally healed well without any additional abscess formation.

Conclusions

A patient who has risk factors for delayed wound healing must be examined thoroughly and extreme care such as exenteration must be taken if there is persistent infection.

Implant infection in porous orbital implants

PURPOSE

To analyze implant infection in patients with porous orbital implants.

METHODS

A retrospective analysis of 212 patients with one of five types of porous orbital implants (bone-derived hydroxyapatite [HA], coralline HA, synthetic HA, porous polyethylene, and aluminium oxide) was conducted. Reasons for surgery, type of surgery, type of implant, peg system used, time of pegging, problems before and after pegging, treatment, and follow-up duration were recorded for all patients, along with additional data including time of onset of infection, microorganism cultured, antibiotics used, patient response to antibiotic therapy, additional interventions, and final status for patients with infection.

RESULTS

Of the 212 patients with porous orbital implants, 116 (54.72%) were pegged. Implant infection was observed in 11 of 116 patients (9.48%) with pegs, whereas 0% of unpegged implants was infected (p = 0.001). The interval between pegging and the onset of infection was 3 to 83 months (average, 36.27 +/- 29.12 months). Implant exposure was noted in 5 of the 11 patients with infection. Symptoms resolved completely with antibiotic treatment in 7 patients. One patient required implant removal as the result of frequent exacerbations. The remaining 3 patients presented with hemorrhagic, purulent discharge and/or pyogenic granuloma on their last visits after being free of symptoms for 5 to 6 months.

CONCLUSIONS

Implant infection is a serious problem that requires additional patient visits, intensive antibiotic therapy, surgery, or some combination of these. Existence of a peg system appears to play a role in implant infection. Infection may develop as late as 6 to 7 years after pegging, and the patient should be cautioned about potential late-onset problems. It is possible to control the infection with appropriate antibiotic therapy; removal should be reserved for refractory cases.

Experience with cranial implant-based prosthetic reconstruction

Reconstruction of acquired or congenitally absent facial structures is a challenging task for the reconstructive surgeon. Often inadequate soft tissue, cartilaginous, or osseous support exists for a reconstruction which is functional, aesthetic, and achieved with a reasonable effort on the part of the surgeon and patient. Prosthetic reconstruction of these structures utilizing cranial implants is a viable option which offers several advantages when compared to traditional reconstructive techniques. We present our experience with 114 cranial implants in 32 patients for craniofacial reconstruction. One hundred fourteen cranial implants were placed in a total of 32 patients for reconstruction of facial structures. Indications for cranial implants with prosthetic reconstruction were lack of adequate tissue for reconstruction, failed reconstructive attempts, and selection of the technique by the patient. Seventy-two implants were placed in the mastoid region, 31 within the orbit, 7 within the nasal cavity, with four additional implants for the reconstruction of eyebrows. Cranial implants were followed by clinical and radiographic examination at intervals ranging from 3-46 months (mean 15.3 months). Patient records were retrospectively reviewed for surgical complications, soft tissue reactions, infections, and implant failures. The total success rate of cranial implantation in the study group was 92.9% (106/114). Surgical complications occurred in three of the 32 patients (9.3%). All cranial implants were successfully reconstructed after integration. Seven percent of the implants failed after initial integration was successful. The rate of significant soft tissue reactions or frank infection observed among the implanted patients was 6.1%. Titanium cranial implants coupled with custom prosthetic reconstruction offer an excellent alternative to traditional surgical techniques in the reconstruction of acquired or congenitally absent facial structures. Predictability, prosthetic adaptability, as well as superior aesthetics are major advantages to this technique when compared to traditional surgical reconstructive techniques.

UK national survey of enucleation, evisceration and orbital implant trends

AIM

To evaluate current clinical practice in the UK in the management of the anophthalmic socket; choice of enucleation, evisceration, type of orbital implant, wrap, motility pegging and complications.

METHODS

All consultant ophthalmologists in the UK were surveyed by postal questionnaire. Questions included their practice subspecialty and number of enucleations and eviscerations performed in 2003. Specific questions addressed choice of implant, wrap, motility pegging and complications.

RESULTS

456/896 (51%) consultants responded, of which 162 (35%) had a specific interest in oculoplastics, lacrimal, orbits or oncology. Only 243/456 (53%) did enucleations or eviscerations. 92% inserted an orbital implant after primary enucleation, 69% after non-endophthalmitis evisceration, whereas only 43% did so after evisceration for endophthalmitis (50% as a delayed procedure). 55% used porous orbital implants (porous polyethylene, hydroxyapatite or alumina) as their first choice and 42% used acrylic. Most implants inserted were spherical, sized 18-20 mm in diameter. 57% wrapped the implant after enucleation, using salvaged autogenous sclera (20%), donor sclera (28%) and synthetic Vicryl or Mersilene mesh (42%). A minority (7%) placed motility pegs in selected cases, usually as a secondary procedure. 14% of respondents reported implant exposure for each type of procedure and extrusion was reported by 4% after enucleation and 3% after evisceration.

CONCLUSIONS

This survey highlights contemporary anophthalmic socket practice in the UK. Most surgeons use porous orbital implants with a synthetic wrap after enucleation and only few perform motility pegging.

Orbital cysts lined with both stratified squamous and columnar epithelia: a late complication of silicone implants

Two patients presented with orbital cysts 5 and 7 years after orbital blowout fracture repair with silicone plate implants. The orbital cysts caused significant exophthalmos and restriction in ocular motility. Surgical excision revealed thick-walled cysts that were displacing the globe and encapsulating the silicone implant. On histopathologic examination, the cysts were lined with both stratified squamous and ciliated columnar (respiratory) epithelia. We propose that squamous and respiratory epithelial cells may have been deposited during surgery from the conjunctival and sinus epithelia, respectively. This case series illustrates that although an uncommon complication, epithelium-lined inclusion cysts may develop several years after orbital fracture repair with a silicone implant. A transconjunctival surgical approach is a possible risk factor.

Pyogenic Granuloma as a Presenting Sign of Hydroxyapatite Orbital Implant Exposure: A Clinicopathologic Study

PURPOSE

We report 5 unusual cases of exposed hydroxyapatite orbital implants that presented as pyogenic granulomas. We propose pathogenesis and histopathologic correlations.

METHODS

A clinicopathologic study of 5 patients with hydroxyapatite implants who presented with pyogenic granuloma.

RESULTS

Pyogenic granulomas were detected 1.5 to 30 months after implantation in 5 patients. The lesions were multiple but were not related to the wound margin at the exposed area and were not covered by the surface epithelium in most instances. Exposure defects were detected in all patients at the time of lesion excision. The mean exposure size in the greatest dimension was 16 mm (range, 9-20 mm). Three patients were treated successfully with simple excision of the granulomas, burring down of the anterior surface of the implants, and direct repair of the exposure defects. Explantation of the implant was performed in 2 cases. Histopathologic examination revealed chronic inflammation and microabscess formation in the explanted implants.

CONCLUSIONS

Five patients with pyogenic granulomas were found to have hydroxyapatite exposure. Pyogenic granuloma should not be considered a benign lesion on a hydroxyapatite orbital implant, especially in recurrent cases. Ophthalmologists must be aware of the possibility of conjunctival dehiscence with hydroxyapatite-implant exposure beneath the lesion.

Conjunctival Squamous Cell Carcinoma of the Orbit 40 Years After Enucleation

Conjunctival squamous cell carcinoma developed in a 51-year-old man 40 years after he had enucleation of his left eye because of an explosion injury. He had worn several ocular prostheses for more than 40 years. Recently he had noticed an increasing sanguineous conjunctival discharge, a foreign body sensation, and swelling of his left lower eyelid. Incisional biopsies of an underlying conjunctival mass revealed squamous cell carcinoma. His work history did not involve exposure to radiation, chemicals, or the sun. The authors concluded that squamous cell carcinoma in this case was caused by chronic irritation as the result of long-standing use of a poorly fitting ocular prosthesis.

Prolonged bradycardia after secondary orbital implant

A patient who suffered a 36 hour symptomatic bradycardia following secondary orbital implant is described. The possible causes and implications are discussed.

Infected Aluminum Oxide Orbital Implant

Porous orbital implant infection is rare. The diagnosis may be delayed as the initial symptoms and signs are not always indicative of implant infection. It is often only with time, a persistence of symptoms and signs, and additional symptoms and signs that implant infection is suspected.

[Our approach in the treatment of exposed hydroxyapatite orbital implant]

PURPOSE

To present our approach in the treatment of exposed hydroxyapatite (HA) orbital implant.

PATIENTS AND METHODS

Seven patients with HA orbital implant exposure presented for treatment, all primary implants, postevisceration. All patients were operated by the same surgeon. The size of implant was based on preoperative axial length measurement (ax-2 mm, subtract 1 mm for evisceration and hyperops) except for two patients with buphthalmus where 20 mm implant was used. HA implant was wraped in sclera papillar area turned anteriorly. It was pushed as far as possible into the orbit but unfortunately without using plastic drape or malleable retractors. Extraocular muscles were sutured in their anatomic position. Exposure occurred at 5-7 years of implantation. Six patients wore glass orbital prostheses, and one silicone orbital prosthesis. The size of dehiscence of conjunctiva and Tenon's capsule varied from 5 to 15 mm. A woman with 15 mm exposure presented first with 6 mm exposure. However, she declined immediate surgery and continued to wear glass epiprosthesis. She returned a year later when she could not wear epiprosthesis anymore, and the size of the defect increased to 15 mm. Two-step procedure was performed in local anesthesia. Conjunctival edges were freshened, undermined and the anterior surface of the HA implant was shaved to the depth of at least 2 mm. Tarsoconjunctival flap was tailored from the central part of the lid. Care was taken that at least four millimeters of the marginal height of the tarsal plate were kept intact to avoid lid notching. Conjunctiva was undermined superiorly to include conjunctiva and Müllers muscle into the flap. No donor sclera was available. Raw surface of the flap faced the defect. Interrupted 6-0 Vicryl sutures were put on the flap, 360 degrees around. In two patients with exposure measuring 9 and 11 mm tarsoconjunctival pedicle flap from lax lower lid was incorporated. Upper and lower lid tarsoconjunctival flaps were sutured together. Central temporary tarsorrhaphy was performed so that postoperative local antibiotic (Tobrex) could be applied through the lateral third of the palpebral opening. At four weeks, flap was divided under local anesthesia. In two patients with lower lid flaps, horizontal shortening of the lower lid for the size of the flap was perfomed. In one patient with a 15-mm defect, third surgery was required. A crescent defect starting from superonasally to inferotemporally, horizontal diameter of 4 mm, was covered with conjunctival pedicle flap, base located inferotemporally. The harvest area was covered with oral mucosa membrane graft. Follow-up varied from 2 months to 5 years.

RESULTS

Two patients experienced thick mucous discharge starting two weeks after the first step of the surgery. Bacteria and fungi were not isolated. After a 10-day course of systemic antibiotics the discharge subsided and the flap had taken nicely. Two patients had granuloma prior to pedicle division, which was removed and the area healed. There was no evidence of further exposure in any patient and all were able to wear orbital epiprosthesis.

CONCLUSION

Tarsoconjunctival pedicle flap is a safe procedure to cover the exposure of hydroxyapatite orbital implant. A limited size of the flap and the need of temporary tarsorrhaphy are the only disadvantages of the procedure.

[Evaluation of results of enucleations with orbital implant in children and adolescents]

PURPOSE

The aim of the research is the assessment of results of enucleation with orbital implant in children.

MATERIAL AND METHODS

Examinations included the group of 99 children between 6 months and 19 years of age. The examined group consisted of 39 boys (39.4%) and 60 girls (60.6%). 96 eyes were removed because of non-regressive retinoblastoma (despite applied treatment), two eyes with buphtalmus (with no light perception), as a result of glaucoma, and one case of medulloepithelioma. The applied implants were: Castroviejo--in 28 patients, Medpor--in 24 patients, Hydroxyapatite--46 patients. In one patient was applied Baush and Lomb orbital implant.

RESULTS

In 91 patients (91.9%) no significant complications occurred. In 2 patients (2%), the hemorrhage occurred during the surgery. Postoperative complications included: in 6 patients (6.1%) exposition of orbital implant was observed; in one patient the exposition was enlarging which led to removal of the implant; in 2 patients with implant exposition (2%) inflammatory granuloma occurred on the edge of the exposition. In one patient (1%) cyst of conjunctiva in the postoperative scar area occurred 3 months after operation.

CONCLUSIONS

Enucleation with orbital implant enables normal development of the orbit and improves cosmetic effect. The frequency of complications depends on type of applied orbital implant.

[Comparative histologic study of implants (magnets) in orbits of female rabbits]

PURPOSE

To evaluate microscopically the signs of inflammatory reaction due to the fixation of an orbitary implant (magnet, covered by gold).

METHODS

An experimental study was performed in 54 adult female rabbits, divided into 3 groups of eighteen with 3 subgroups of 6; an evaluation at 1, 3 and 6 postoperative weeks was performed. An implant (magnet, covered by gold) was fixed in the inferior orbital rim using biologic glue, screw or unabsorbable suture (Mersilene 5.0). The opposite orbits (without implants) represented the control group.

RESULTS

Microscopic signs of inflammatory reaction due to orbitary fixation of the implant were observed with the use of the three methods (biologic glue, screw or unabsorbable suture) (Mersilene 5.0), until six weeks of the postoperatory period.

CONCLUSIONS

Histopathological signs of inflammatory reaction to the implant and to its orbital fixation were observed up to the sixth week, with cyanoacrylate, screw, or unabsorbable suture (Mersilene 5.0), with prevalence of the chronic inflammatory process and cicatricial fibrosis, without statistically significant difference in most of the cases.

Hertel Curve: Orbital Volume Increment and Proptosis in a Cadaver Model

PURPOSE

This study examined the relation between effective orbital volume increment and proptosis induced by an inflatable orbital implant in a human cadaver orbit.

METHODS

A 25-ml inflatable latex balloon was inserted between the periorbita and orbital floor in 15 human cadavers. Hertel measurements were taken for each milliliter over a total 7-ml volume increment. Five trials per orbit for 15 cadavers resulted in 525 data points.

RESULTS

Average exophthalmos per milliliter of volume increment was plotted over 7 ml, using 1-ml volume increments. The resultant curve, which was termed a Hertel curve, was linear over 7 ml (R > 99%) and had a slope of 0.62 mm per milliliter of volume increment.

CONCLUSIONS

An inflatable orbital implant is an effective tool for introducing a specified amount of volume in the cadaver orbit. The predictable relation between proptosis and volume increment (Hertel curve) may be a useful tool for surgeons in planning the size of an implant required to surgically correct enophthalmos.

Chronic inflammation from polycarbonate motility peg inhibits osteogenesis in a human hydroxyapatite orbital implant

The histologic findings of a pegged hydroxyapatite orbital implant removed due to chronic inflammation and pain are described. A 44-year-old woman underwent explantation of a hydroxyapatite sphere and polycarbonate motility peg due to chronic redness, swelling, discharge, and pain. Histology revealed complete fibrovascularization of the implant, with approximately 90% ossification. No bone marrow was identified. Histologic sections revealed fibrous connective tissue at the periphery of a sclerotic bony mass with a granulomatous inflammatory infiltrate at the motility peg aperture. There were no bacterial, mycobacterial, or fungal organisms identified histologically or by culture. Consistent with previous reports, hydroxyapatite orbital implants are amenable to fibrovascular ingrowth and bony transformation. The presence of a granulomatous inflammatory reaction around the polycarbonate motility peg in this case may have prevented complete osseous transformation of the hydroxyapatite implant.

Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response

Several implants for orbital wall fracture treatment are available at the present, but they have drawbacks: resorption, risk for migration and foreign body reaction. Alloplastic resorbable implants would be advantageous: no removal operation and no donor side morbidity. The purpose of this study was to evaluate the foreign body reaction, capsule formation and mechanical properties of two bioresorbable implants. PDS and SR-P(L/DL)LA mesh sheet (70/30) with solid frame (96/4) implants (SR-P(L/DL)LA 70,96) were placed into subcutaneous tissue of 24 rats. Immunohistochemistry was used to evaluate reactivity for Tn-C, alpha-actin, type I and III collagens and two mononuclear cells: T-cells and monocyte/ macrophage. GPC, DSC and SEM were performed. Student's t-test or nonparametric Kruskall-Wallis test were used for statistical analysis. Histology of peri-implant capsule exhibited an inner cell-rich zone and an outer connective tissue zone around both materials. Tn-C reactivity was high in the inner and alpha-actin in the outer zone. At the end of the study, the difference of type I collagen versus type III collagen reactivity in inner zone was statistically significant (P<0.0001) as was the difference of type I collagen versus type III collagen reactivity in outer zone (P<0.0001). Immunohistochemistry did not reveal any statistical differences of T-cell and monocyte/macrophage reactivity around PDS versus SR-P(L/DL)LA 70,96 implants, nor any differences as a function of time. PDS were deformed totally after 2 months. SR-P(L/DL)LA 70,96 implants were only slightly deformed during the follow up of 7 months. PDS degraded rapidly in SEM observation. Particles were detaching from surface. SEM observation revealed that polylactide implant was degrading from the surface and the inner porous core became visible. The degradation came visible at 7 months. There were cracks in perpendicular direction towards to the long axis of the filaments. M(w) of PDS decreased fast compared to the polylactide implant. Foreign body reaction was minimal to both materials but continued throughout the whole observation period. Mechanically PDS was poor, it looses its shape totally within 2 months. It cannot be recommended for orbital wall reconstruction. New mesh sheet-frame structure (SR-P(L/DL)LA 70,96) approved to be mechanically adequate for orbital wall reconstruction. It seems not to possess intrinsic memory and retains its shape. The resorption time is significantly longer compared to PDS and is comparable to other studied P(L/DL)LA copolymers. Thus, the new polylactide copolymer implant may support the orbital contents long enough to give way to bone growth over the wall defect.

Enucleation With Unwrapped Porous and Nonporous Orbital Implants: A 15-Year Experience

PURPOSE

To compare the rates of implant exposure and implant migration among patients who received an unwrapped nonporous spherical implant versus an unwrapped porous spherical implant immediately after enucleation.

METHODS

Retrospective analysis of a series of 258 patients who received either an unwrapped nonporous spherical implant (n = 68) or an unwrapped porous spherical implant (n = 190). Actuarial rates of migration of the implant and conjunctival dehiscence leading to implant exposure were computed.

RESULTS

Sixty-eight patients received an unwrapped nonporous implant (polymethylacrylate [PMMA]) and 190 patients received an unwrapped porous implant (139 hydroxyapatite [HA] and 51 porous polyethylene [Medpor]). Median follow-up duration in this study was 37.6 months. Implant exposure occurred in 1 of the 68 nonporous implant cases (1.5%) and in 4 of the 190 porous implant cases (2.1%). This difference is not statistically significant (P = 0.85). In contrast, clinically significant implant migration occurred substantially more frequently in the patients who received a nonporous implant. The cumulative actuarial probability of implant migration at 60 months was 15.5% for the nonporous implants versus 0.7% for the porous implants. This difference was statistically significant (P = 0.0003).

CONCLUSIONS

Orbital implant migration occurred in a significantly greater proportion of patients who received a nonporous implant than in those who received a porous implant. Implant exposure occurred at a low rate that was not significantly different in the two subgroups.

Chronic subperiosteal hematic cyst formation twelve years after orbital fracture repair with alloplastic orbital floor implant

An 89-year-old female patient with a history of a left orbital floor fracture repair with synthetic implant 12 years prior, presented with a three-week history of blurry vision, inferior conjunctival chemosis and proptosis of the left eye. CT scan revealed a well-circumscribed subperiosteal lesion with superior elevation of the orbital floor implant. The patient underwent transconjunctival orbital surgery with removal of the implant and drainage of the subperiosteal hemorrhagic cyst. The patient had an uncomplicated postoperative course, with resolution of the proptosis, chemosis, and return of normal vision. This case represents an unusual late complication of orbital fracture repair with associated reduced visual acuity.

A comparison of implant extrusion rates and postoperative pain after evisceration with immediate or delayed implants and after enucleation with implants

PURPOSE

To examine implant extrusion rates after evisceration with immediate or delayed implants in patients with culture-proven endophthalmitis. To compare postevisceration and postenucleation pain.

METHODS

This prospective, nonrandomized interventional case series included four groups of patients: group 1, 25 endophthalmitis patients undergoing evisceration with immediate implants; group 2, 15 endophthalmitis patients undergoing evisceration with delayed implants; group 3, 31 patients without endophthalmitis undergoing evisceration with immediate implants; and group 4, eight patients undergoing enucleations with implants. Standardized techniques and follow-up schedules were used. Postoperative pain was assessed by weighted frequency of pain medications used during two 48-hour periods. Statistical analysis was performed. Retrospective review of two series of patients undergoing evisceration was performed.

RESULTS

No cases of implant extrusion occurred during an average follow-up of 37.9 months. Average implant size was 19.0 mm. Conjunctival dehiscence occurred in one patient. Average total pain scores were 20.8 in endophthalmitis patients with immediate implants; 22.1 in endophthalmitis patients with delayed implants; 20.3 in patients without endophthalmitis and with immediate implants; and 23.1 in patients with enucleations and immediate implant insertions. Retrospective review suggested possible causes of implant extrusion.

CONCLUSION

Both immediate and delayed implant techniques appear safe in patients with endophthalmitis, with the former being simpler, more cost-effective, and perhaps less painful. Prolonged antibiotic therapy and smaller implants may render a false sense of security against implant extrusion; good surgical technique and meticulous postoperative wound care are essential. Postenucleation pain appears more severe than postevisceration pain.

Integrated reconstructive strategies for treating the anophthalmic orbit

INTRODUCTION

Anophthalmia may be congenital or acquired. Congenital anophthalmia refers to any orbit that contains a severely hypoplastic eye at birth (microphthalmia), or a complete absence of the globe due to failure of optic vesicle formation. In both those cases the aim of surgery is to stimulate adequate orbital growth. Acquired anophthalmic orbit may be due to trauma or tumour. In acquired forms the goal is restoration of orbital volume with adequate replacement of orbital contents.

PATIENTS AND METHODS

In this study 28 patients (6 cases of congenital and 22 of acquired anophthalmia), were treated between October 1997 and August 2002, by applying protocols that are based on data from the literature.

RESULTS

In 19 cases there were satisfactory results. Complications such as implant dislocation (3 cases), residual asymmetry (2 cases), and eyelid retraction required revisional surgery (4 cases).

CONCLUSIONS

The different strategies applied for reconstructing the missing structures of the orbit in the congenital forms have given satisfactory results related to the type and complexity of the deformity. In rehabilitating a patient with an acquired anophthalmic orbit it is essential to ensure that the patient has realistic expectations regarding a final prosthesis. Interaction of the various healthcare professionals is also essential to help the patient and so develop new prosthetic devices as well as innovative methods for socket reconstruction.

The smooth surface tunnel porous polyethylene enucleation implant

BACKGROUND AND OBJECTIVE

To describe early clinical results with the porous polyethylene smooth surface tunnel (SST) enucleation implant.

PATIENTS AND METHODS

Uncontrolled, prospective interventional case series of patients undergoing enucleation with placement of the SST implant. This implant consists of a porous polyethylene sphere with a smooth anterior surface containing pre-drilled tunnels to facilitate direct suturing of the rectus muscles to the implant without use of an implant wrap. Postoperatively, socket healing was assessed, and prosthesis and socket motility were evaluated by the surgeon using an ordinal scale (0 = no motility to 4 = excellent motility).

RESULTS

Thirty patients received the SST implant, with a mean follow-up of more than 23 months. Two cases of exposure occurred and were managed surgically without the need for explantation. Mean socket motility was 3.1 on a 0 to 4 ordinal scale, with mean prosthesis motility of 2.8.

CONCLUSION

The SST implant provides satisfactory socket motility and is generally well tolerated in the anophthalmic socket without the need for wrapping material.

Late porous polyethylene implant exposure after motility coupling post placement

PURPOSE

To report the probable association of motility coupling post placement and late porous polyethylene implant exposure.

DESIGN

Retrospective, observational case series.

METHODS

This was a retrospective analysis of 27 patients who had primary porous polyethylene orbital implantation from February 1999 to November 2000. Data on demographics, previous surgery, ocular diagnosis, type of surgery, size of the implant, and motility coupling post placement were collected. Complications of porous polyethylene implants and implant exposure were documented.

RESULTS

Among the 27 patients, 18 eyes (66.7%) received motility coupling post insertion after primary porous polyethylene implantation. Implant exposure occurred in six (33.3%) of the 18 eyes with motility coupling post insertion. None of the eyes without insertion had implant exposure. The mean interval between porous polyethylene implantation and motility coupling post placement for the implant exposure group (6 of 18) was 6.5 +/- 0.4 months, which was not statistically significant compared with 7.2 +/- 0.6 months in the nonexposure group (12 of 18). For these 6 cases of implant exposure, the mean interval between implantation and implant exposure was 24.2 +/- 11.8 months, and the mean interval between pegging and exposure was 17.6 +/- 11.7 months. Among these 6 patients, 4 underwent removal of exposed porous polyethylene implants and reimplantation of hydroxyapatite implant or dermis fat reconstruction.

CONCLUSIONS

We found a trend (P =.07) of increasing risk of porous polyethylene implant exposure with motility coupling post placement. Although the pegging group did not show a statistically significant higher rate of exposure compared with the nonpegging group, we believe that more care was needed when performing motility coupling post placement. In addition, longer postoperative follow-up is needed after insertion of a motility coupling post.