Porous polyethylene implants in orbital floor reconstruction

The purpose of this article is to present the authors' experience with the use of porous polyethylene ultrathin sheets for orbital floor reconstruction. Thirty-two patients with orbital floor fractures were treated with porous polyethylene ultrathin sheets. Sixteen cases corresponded to orbitozygomatic fractures, 11 cases corresponded to pure orbital floor fractures, and five corresponded to panfacial fractures. The subciliary approach was used in 15 patients and the transconjunctival approach in nine; another three patients were operated on through a preexisting eyebrow wound, two were operated on with a subtarsal approach, two were operated on through an eyebrow extension of a facial wound, and one patient was operated on through the facial wound. Intraoperatively, all patients received a prophylactic dose of intravenous antibiotics. Postoperatively, 24 patients received amoxicillin clavulanate for 5 to 7 days, two patients received clindamycin, and six patients received no antibiotics. Enophthalmos was corrected in 15 of 24 patients (62.5 percent), and hypoglobus in nine of 11 (82 percent). Diplopia was resolved in 25 of 28 patients (89.3 percent) with preoperative impairment. Extrinsic eye movement impairment was resolved in 25 of 27 patients (92.6 percent). A preoperative visual acuity deficit was present in four patients (12.5 percent) and was resolved in one (from 20/100 to 20/20). Visual acuity improved in one patient (from 20/60 to 20/30). In the other two patients, visual acuity remained altered (from 20/30 to 20/30). One patient (3.1 percent) suffered blindness induced by surgery. Nine of 26 patients (34.6 percent) had residual infraorbital nerve hypesthesia and five (19.2 percent) had residual paresthesias. Postoperatively, epiphora was present in six patients (18.8 percent) and ectropion in five (15.6 percent). Although there was no statistical significance between the surgical approach and the presence of epiphora (p = 0.211) and ectropion (p = 0.422), patients who were treated using the transconjunctival approach suffered reduced ectropion (0 percent) compared with patients treated using the subciliary approach (20 percent). However, patients treated using the transconjunctival approach suffered increased epiphora (22.2 percent) compared with those treated with the subciliary approach (13.3 percent). There were four cases (12.5 percent) of postoperative facial infections. Two of these cases were resolved with systemic antibiotics, one was resolved with bone sequestrum resection, and one patient needed removal of the implant. Orbital infections were related in all cases to titanium osteosynthesis miniplates or skull bone graft. When comparing patients who were treated with and without antibiotics, no statistical differences (p = 0.958) were found relative to the presence of infections. Correction of hypoglobus is technically easier than enophthalmos, because enophthalmic correction requires a wide, deep subperiosteal dissection and implant positioning, posterior to the equator of the globe, with the inherent risk of orbital apex injury.     

Osteochondral reconstruction of a non-weight-bearing joint using a high-density porous polyethylene implant

Currently, there is no reliable reconstructive modality allowing anatomic resurfacing of traumatic digital osteochondral articular defects. The purpose of the present study is to demonstrate the utility of Medpor, a high-density porous polyethylene (HDPP) scaffold biomaterial that can (1) be readily contoured to fit any joint defect, (2) permit stable internal fixation, and (3) permit osteocyte and chondrocyte ingrowth and subsequent articular cartilage resurfacing necessary to restore joint congruity. HDPP has gained wide acceptance for use in craniofacial and skeletal reconstruction and augmentation. An avian non-weight-bearing joint model was designed to study the role of the HDPP implant in small joint reconstruction. An osteochondral defect was created with a 5-mm circular punch in the humeral articular surface of both glenohumeral joints of 32 adult White Leghorn chickens. In each animal, one defect was press-fitted with a correspondingly sized HDPP implant (HDPP implant group); the contralateral defect was filled with the original osteochondral plug (isograft group) or left unrepaired (control group). At 2 weeks, and 1, 3, and 6 months,joints from each group were harvested and evaluated. Over the 6-month study period, joints in the control group demonstrated healing with dense collagenous scar tissue leaving residual defects at the articular surfaces and significant degenerative disease of the glenohumeral joints radiographically. Joints in the isograft group demonstrated near-complete resorption with some preservation of the cartilaginous cap but overall depression of the articular surface and significant degenerative joint disease. Joints in the HDPP implant group demonstrated stable fixation by highly mineralized bony trabecular ingrowth, preservation of the articular contour of the humeral head, and no evidence of significant degenerative joint disease. These findings indicate a potential role for this high-density porous polyethylene implant in the reconstruction of small joint articular and osseous defects.     

Facial palsy and reconstruction

This article outlines a thorough approach to facial nerve palsy and reconstruction.     

Comparison of the biological activities of high-density porous polyethylene implants and oxidized regenerated cellulose-wrapped diced cartilage grafts

The use of alloplastic materials in plastic surgery has become more extensive with advancement of autogenous-tissue reconstruction techniques for the repair of defects, tissue augmentation, and the stabilization of bones. An ideal alloplastic material should be nonallergenic, noncarcinogenic, sterilizable, and easy to shape and should not cause rejection. Alloplastic material used for tissue augmentation should have a low rate of resorption and distortion. High-density porous polyethylene implants (Medpor) have been used widely and successfully for tissue augmentation. The Turkish Delight is a material composed of diced cartilage grafts wrapped in oxidized regenerated cellulose (Surgicel). Its indications are similar to those of the Medpor implant, and an additional donor site is usually not needed. Both materials are used in the same anatomical locations, especially for augmentation. Therefore, the authors evaluated the long-term stability of and suitable anatomical sites for these materials. Medpor implants or Turkish Delights were placed subperiosteally or subfascially in 10 young rabbits, and the resultant changes were evaluated 16 weeks after the operation by macroscopy and histopathology. Changes in projections were measured with an ocular micrometer. Medpor implants were neither resorbed nor distorted when placed subperiosteally or subfascially, and were highly stabilized by the surrounding tissues. Turkish Delight also enabled tissue augmentation, but had a significantly higher rate of resorption compared with the Medpor implant and was loosely bound to the surrounding tissue. The Turkish Delight was less resorbed and better fixed to adjacent tissues when placed subperiosteally than when placed subfascially.     

Facial skeletal changes following hypertelorbitism correction

This is a retrospective study of skeletal changes in 19 patients with corrected hypertelorism. A favorable outcome, defined as relapse less than 5 mm, occurred in patients with an average interorbital distance of 32 mm, whereas patients with an average interorbital distance of 40 mm tended to relapse over 5 mm. Neither age, interorbital configuration, nor diagnosis affected the stability of orbital translocation. At last evaluation (mean 6.7 years postoperatively), the mean interorbital distance was 22.4 mm in the favorable outcome group and 28.3 mm in the unfavorable category. This study suggested that the standard hypertelorism operation may interfere with anterior facial growth. Unless psychosocial factors predominate in a child with mild deformity, repair should be postponed until late adolescence. In a young child with gross telorbitism, nasoethmoidal resection and transmaxillary osteotomies or facial bipartition is justified. Another long-term skeletal problem was resorption of the reconstructed nasal complex. Technical and biological explanations for this are given. The correction of hypertelorism is surgery of the nose and of the midface.     

Behavioral recovery from traumatic brain injury after membrane reconstruction using polyethylene glycol

Polyethylene glycol (PEG; 2000 MW, 30% by volume) has been shown to mechanically repair damaged cellular membranes and reduce secondary axotomy after traumatic brain and spinal cord injury (TBI and SCI respectively). This repair is achieved following spontaneous reassembly of cell membranes made possible by the action of targeted hydrophilic polymers which first seal the compromised portion of the plasmalemma, and secondarily, allow the lipidic core of the compromised membranes to resolve into each other. Here we compared PEG-treated to untreated rats using a computer-managed open-field behavioral test subsequent to a standardized brain injury. Animals were evaluated after a 2-, 4-, and 6-hour delay in treatment after TBI. Treated animals receive a single subcutaneous injection of PEG. When treated within 2 hours of the injury, injured PEG-treated rats showed statistically significant improvement in their exploratory behavior recorded in the activity box when compared to untreated but brain-injured controls. A delay of 4 hours reduced this level of achievement, but a statistically significant improvement due to PEG injection was still clearly evident in most outcome measures compared at the various evaluation times. A further delay of 2 more hours, however, eradicated the beneficial effects of PEG injection as revealed using this behavioral assessment. Thus, there appears to be a critical window of time in which PEG administration after TBI can provide neuroprotection resulting in an enhanced functional recovery. As is often seen in clinically applied acute treatments for trauma, the earlier the intervention can be applied, the better the outcome.     

Breast reconstruction with implants and expanders

Breast reconstruction with expanders and implants provides an excellent option in the properly selected patient. Techniques for reconstruction have evolved significantly over the past 30 years with the development of more sophisticated devices and improvement in surgical procedures. Several options exist, each with its own advantages and disadvantages. Two-stage breast reconstruction using a textured device with an anatomic shape and integrated valve seems to provide the most consistent and reproducible results in most patients. Those patients with small, minimally ptotic breasts may be candidates for either single-stage implant reconstruction or reconstruction with an adjustable device. Advantages of expander and implant reconstruction over other techniques include relative ease of the procedure; no distant donor-site morbidity; use of tissue of similar color, texture, and sensation; reduced operative time; and more rapid postoperative recovery.     

Facial skeletal growth after timed soft-tissue undermining.

This study was designed to answer the following questions: (1) Does aggressive bilateral soft-tissue undermining of the nasomaxillary complex in an immature animal without an iatrogenically produced cleft lip significantly inhibit growth? (2) If so, is the early timing of this undermining crucial? Fifty New Zealand White rabbits were used in this study, and bilateral buccal sulcus incisions with extensive nasomaxillary supraperiosteal undermining were performed in the experimental groups. There were five groups: (1) control, (2) undermining at 3 to 4 days, (3) undermining at 7 to 10 days, (4) undermining at 18 to 21 days, and (5) undermining at 50 to 56 days. The animals were sacrificed at 6 months of age, and direct osteometric measurements were made. Results demonstrated that a significantly retruded, constricted, and vertically shortened maxilla was produced as a direct result of bilateral nasomaxillary soft-tissue undermining alone regardless of the timing.     

Functional reconstruction after a total maxillectomy using a fibula osteocutaneous flap with osseointegrated implants

The fibula osteocutaneous flap with osseointegrated implants was used for reconstruction of a total maxillectomy defect. We have achieved satisfactory reconstruction of three-dimensional facial structure, orbit support, and a functional prosthesis. Our procedure restored the patient's masticatory function of the maxilla and enabled good speech and a natural facial appearance. A very high quality of function was obtained without any complications, but long-term follow-up is necessary for maintenance of the implants.     

Facial skeletal expansion: treatment strategies and rationale.

Forty-three nonconsecutive patients presenting with dentofacial deformity underwent surgical procedures designed intentionally to create skeletal disproportion in the sagittal and/or vertical dimensions. This was accomplished through expansion (enlargement) of the facial skeleton beyond normative standards. At the time of follow-up, which ranged from 14 to 36 months (mean 18.4 months), soft-tissue cephalometric analyses documented facial disproportion to exist in 37 of the 43 patients treated. Thirty-two patients had excessive anterior divergence (facial protrusion) at pogonion, and 17 patients had excessive lower face height as measured from subnasale to menton. All patients were judged to have had a favorable aesthetic outcome. This philosophy of facial skeletal expansion is predicated on two concepts: The first of these is that facial proportions and dimensions beyond those which are considered normal may be extremely attractive in a given individual. Second, the soft-tissue response to skeletal expansion is more favorable and predictable than it is to skeletal contraction in providing for well-supported soft tissues. This treatment planning approach is based on the dynamic interrelationship between the skeletal foundation and the soft-tissue facial mask. It relies on physical examination as the major determinant of aesthetic surgical options.     

Breast reconstruction using tissue expanders and implants in Hodgkin's patients with prior mantle irradiation.

Women treated for Hodgkin's disease with mantle irradiation have an increased risk for developing breast cancer. Typically, breast malignancy in Hodgkin's patients presents bilaterally in a younger age group. Skin flap ischemia, poor skin expansion, implant extrusion, capsular contracture, and poor cosmesis are common sequelae of tissue expander/implant breast reconstruction after breast irradiation for failed breast conservation therapy. This has led most surgeons to favor autologous tissue reconstruction in this setting. This study was performed to determine the efficacy of tissue expander/implant breast reconstruction in breast cancer patients who have been treated with prior mantle irradiation for Hodgkin's disease. A retrospective analysis of all breast cancer patients with a history of Hodgkin's disease and mantle irradiation treated with mastectomy and tissue expander/implant reconstruction between 1992 and 1999 was performed. There were seven patients, with a mean age of 35 years (range, 28 to 42 years). The average interval between mantle irradiation and breast cancer diagnosis was 16 years (range, 12 to 23 years). All patients underwent two-stage reconstruction. Textured surface tissue expanders were placed in a complete submuscular position at the time of mastectomy. Expansion was initiated 2 weeks after insertion and continued on a weekly basis until completion. Expanders were replaced with textured surface saline-filled implants as a second stage. Patients were evaluated for skin flap ischemia, infection, quality of skin expansion, implant extrusion, capsular contracture, rippling, symmetry, and final aesthetic outcome. Breast cancer was bilateral in five patients and unilateral in two. Two patients did not undergo simultaneous bilateral breast reconstruction because of metachronous cancer development. One of the patients had an initial transverse rectus abdominis muscle flap breast reconstruction, followed by a tissue expander/implant reconstruction of the opposite breast. The average follow-up was 3 years. Complications were limited to one case of cellulitis after implant placement that resolved with intravenous antibiotics. There were no cases of skin flap ischemia, poor skin expansion, or implant extrusion. Overall patient satisfaction was high and revisions were not requested or required. Symmetry was best achieved with bilateral implants. This study demonstrates the efficacy of tissue expander/implant breast reconstruction in patients treated with prior mantle irradiation. In this series, tissue expansion was reliable with low morbidity. Second-stage placement of permanent implants yielded good aesthetic results without significant capsular contracture. Mantle irradiation did not appear to compromise the prosthetic breast reconstruction. Tissue expander/implant breast reconstruction should remain a viable option in this category of irradiated patients.     

Late breast pain following reconstruction with polyurethane-covered implants

Two patients of 56 who were reconstructed with polyurethane-coated implants developed breast pain as a late complication and eventually required implant removal for relief. Although the cause of pain was not proven, it may have been due to contracture of the fibrous capsule which formed between the polyurethane and the shell of the implant. The complication of late pain has not been stressed previously in the literature on reconstruction.