A retrospective review of clinical outcomes was performed to determine the clinical utility and morbidity associated with the use of porous polyethylene facial implants. Three hundred seventy implants were placed in 162 consecutive patients, in 178 operations performed in 11 years. The number of patients, the number of implants used, and the average follow-up period were categorized according to the cause of the deformity. The resultant distribution was as follows: acquired (tumor-related), 17 patients, 39 implants, and 30 months; congenital, eight patients, 31 implants, and 92 months; aesthetic, 39 patients, 97 implants, and 24 months; secondary posttraumatic, 48 patients, 139 implants, and 37 months; and acute trauma (internal orbit reconstruction), 50 patients, 64 implants, and 9 months. The distribution of implants according to location was as follows: frontal, 21; temporal, 30; internal orbit, 145; infraorbital rim, 28; malar, 58; paranasal, 29; nasal, 13; mandible, 24; and chin, 22. The combined average follow-up period per patient was 27 months (range, immediate postoperative period to 11 years). All implants were placed in the subperiosteal plane, and the majority were fixed with titanium screws. Antibiotics were administered perioperatively. No implants were extruded or migrated, formed clinically apparent capsules, or caused symptoms attributable to bioincompatibility. The overall reoperation rate was 10 percent (n = 16), which included operations to remove implants because of acute infections (2 percent, n = 3) or a late infection (1 percent, n = 1), to remove implants causing displeasing contours (2 percent, n = 3), and to improve contours (6 percent, n = 9). Porous polyethylene implants have biomaterial properties favorable for facial skeletal augmentation. Screw application of the implants to the skeleton allows precise predictable contouring, thus limiting the need for revisional surgical procedures.
The peer-reviewed literature reports the successful use of various polymers and ceramics to augment the contours of the facial skeleton. In 1997, a comprehensive review of all English-language publications revealed that the use of facial implants was associated with low morbidity rates, although rates were material and site dependent. 1 The literature published after 1997 similarly reports clinical efficacy with low morbidity rates. However, the many case reports of late, implant-related complications 2-21 suggest that the reported, highly favorable experience with facial implants might not adequately represent the actual experience. This lack of correlation has two possible explanations. One is that the majority of clinical studies involve limited follow-up times. Patients with implant complications may be treated by other physicians while being lost to follow-up monitoring by the primary surgeon. Many articles were not included in the 1997 review because they made no mention of follow-up time. The other major reason that the published complication rates do not reflect the actual experience is that clinicians rarely publish a series with poor results.
This article reviews one surgeon's experience with the use of porous polyethylene (marketed as Medpor Biomaterial; Porex Surgical, Newman, Ga.) to augment the craniofacial skeleton. The pore size of this biomaterial allows fibrous tissue ingrowth and thus relative implant incorporation. This is in contrast to smooth-surface implants (such as silicone rubber), which inevitably become encased in a fibrous tissue capsule through the host foreign body response. Encapsulation and predisposition to movement are responsible for the majority of late complications reported for smooth-surface implants. 2-11,13,14,16-20,22-27 As noted in the available literature, 28-39 I have not observed capsule-related complications with the use of porous polyethylene. Unlike the majority of clinical reports describing the use of facial implants, however, this study presents a large number of consecutive patients, with longer follow-up periods. During an 11-year period, 370 porous polyethylene implants were placed in 162 patients. All implants were placed in the subperiosteal plane, and the majority were fixed with titanium screws. The distribution of implants according to the location and cause of the deformity, the associated morbidity rates, and the follow-up periods are documented. General principles and techniques and clinical examples are presented.