Pediatric plastic surgery revisited.

Improvements in surgical technique and an ever improving understanding of the embryologic and cellular origin of many congenital anomalies marks the gains made during the last decade in pediatric plastic surgery. This contemporary review highlights many of these advancements in the diverse array of birth and surgical defects.

Bipedicle fasciocutaneous flaps for inframalleolar vascular graft coverage at the ankle/foot.

In 9 patients requiring inframalleolar bypass (11 extremities), intraoperative consult revealed exposed saphenous vein grafts at either the medial ankle or the dorsum of the foot in which primary wound closure resulted in the reduction or occlusion of blood flow. In these patients, longitudinally oriented bipedicle fasciocutaneous flaps were raised with widths of 3 to 4 cm and lengths ranging from 12 to 18 cm, with Doppler confirmation of discrete fascial perforators. Split-thickness skin grafts were placed in the wake of the flaps. Patient follow-up ranged from 2 to 78 months. All wounds healed, and 10 of 11 limbs were salvaged. Bipedicle flap coverage allows reconstruction of soft-tissue defects with the transposition of local tissues of similar qualities, avoiding the need for more complex distant tissue reconstruction. The inclusion of the deep fascia with the flap enhances its vascular perfusion, even in the ischemic lower extremity, with concurrent revascularization. The reliability of this type of flap is not dependent on traditional concepts of length-to-width ratios, but rather on standard principles of angiosome anatomy.

Free fibular flap reconstruction in mandibular osteopetrosis.

Extensive involvement of the mandible with sclerosis secondary to the rare genetic disorder, osteopetrosis, is a difficult reconstructive problem. It is typically refractory to conservative management or local surgical methods because of vascular compromise of the bone. For this reason, total resection of all involved bone with microvascular graft reconstruction is an ideal method for mandibular reconstruction in osteopetrosis that has not been previously reported.

Compartmentalized bone regeneration of cranial defects with biodegradable barriers: an animal model.

In bony defects of the cranium, bone healing may be complicated by prolapse of surrounding tissue into the defect. This tissue acts as an impediment to prevent the migration of osteogenic cells, leading to impaired bone formation. It has been previously shown that a membrane placed over the bony defect inhibits the connective tissue cells from entering the wound and theoretically improves bone formation. The use of a proven resorbable material, Lactosorb, is used in this animal model and has shown a significant increase in autogenous bony formation. The majority of previous work was accomplished with nonresorbable material that resulted in foreign body formation. This paper is unique because resorbable material in the animal model is relatively inexpensive and easy to use and has allowed successful autogenous bony regeneration.

Experimental assessment of the revascularization of acellular human dermis for soft-tissue augmentation.

The purpose of this experimental study was to determine whether acellular human dermis was capable of complete revascularization in a subcutaneous implantation site with various placement geometries. In young adult rabbit ears, four different sheet and rolled configurations were placed and harvested after 3, 7, 14, and 28 days with silicone rubber microangiographic injections followed by histologic analysis. Revascularization of single-layer acellular human dermis occurred rapidly and was essentially complete by 14 days after surgery. No differences were observed in the ingrowth of vessels regardless of how the basement membrane was oriented. In rolled configurations, vascular ingrowth throughout the implant was slower and had not completely penetrated the grafts by 28 days after surgery at study completion. Vessel ingrowth occurred through the implant surfaces contacting the surrounding soft tissue and along the open seam of the roll. No differences were seen whether the basement membrane was oriented on either the inside or the outside of the roll. Acellular human dermis is capable of significant revascularization of its compact collagen composition in the early postoperative period. In thicker geometries, the rate and completeness of vessel ingrowth are predictably slower. Whether complete revascularization of multilayered or rolled grafts is achieved cannot be determined from this study.

Fixation of bimaxillary osteotomies with resorbable plates and screws: experience in 20 consecutive cases.

PURPOSE: This study evaluated the potential effectiveness of resorbable plate and screw fixation for skeletal stabilization of simultaneously performed maxillary and mandibular osteotomies. PATIENTS AND METHODS: Twenty consecutive patients underwent simultaneous maxillary and mandibular osteotomies that were fixed using copolymeric poly L-lactic acid/polyglycolic acid (PLLA/PGA) plates and screws. Prefabricated acrylic intermediate and final splints were used as guides and then removed at completion of the surgery. Guidance elastics were applied at 2 weeks postoperatively. RESULTS: The LeFort I osteotomies included segmentalizations with and without bone grafts (7/20), impactions (4/20), advancements (8/20), and unilateral downgrafting with a bone graft (2/20)- one of which was segmental. The mandibular sagittal split osteotomies involved advancements (11/20), setbacks (5/20), and asymmetric rotation (4/20). Three patients had simultaneous genioplasties, which were also stabilized with resorbable fixation. All maxillae were fixed with four 2.0-mm L-shaped plates and screws. The mandibular rami were maintained with three 2.5-mm bicortical screws per side. The mandibular symphyseal segments were held in position with two or three 2.5 mm bicortical screws. All surgeries were accomplished uneventfully, and no problems in the immediate postoperative stability of the occlusion were encountered. Follow-up ranged from 12 to 25 months. CONCLUSIONS: The initial clinical findings suggest that this form of bone fixation is a viable alternative to standard metallic fixation techniques for certain maxillomandibular deformities in which excessive bony movements are not performed. Differences exist in both intraoperative application and postoperative management of masticatory function. This is partially a US government work. There are no restrictions on its use.

The fate of resorbable poly-L-lactic/polyglycolic acid (LactoSorb) bone fixation devices in orthognathic surgery.

PURPOSE: The aim of this study was to evaluate the long-term outcome of resorbable poly-L-lactic/polyglycolic acid (PLLA-PGA) bone fixation devices used for fixation of maxillary and mandibular osteotomies. MATERIALS AND METHODS: Twelve patients were postoperatively evaluated. Eight patients who had undergone bilateral sagittal split mandibular osteotomies that had been fixed with PLLA-PGA screws were followed-up for up to 2 years postoperatively with radiographs. One of these patients underwent a bone biopsy for detailed histologic evaluation of the screw fixation sites. Two patients who had undergone mandibular symphyseal osteotomies were also radiographically evaluated at 18 months to 2 years postoperatively. Two patients who had Le Fort I osteotomies fixed with PLLA-PGA plates and screws underwent open exploration of the operated sites for visual examination. RESULTS: All 8 mandibular osteotomy patients showed radiographic screw hole lucency immediately after surgery that remained unchanged in the first year after surgery. By 18 months postoperatively, all 48 screw holes showed near or complete trabecular bone fill. The bone biopsy of one screw hole at 2 years postoperatively showed complete fill with normal trabecular bone. No residual polymer material or fibrous scar was seen. The mandibular symphyseal sites showed complete elimination of all screw holes by 2 years postoperatively, with only faint evidence of intraosseous tunnels. The maxillary sites showed complete bone healing along the osteotomies and no evidence of residual fixation material or bone defects in the screw holes. No communication with the maxillary sinus was seen in the fixation sites. CONCLUSION: This orthognathic patient series showed complete resorption of the PLLA-PGA fixation devices without osteolysis in maxillary and mandibular bone sites by 18 to 24 months after surgery.

Management of alveolar cleft bone grafting--state of the art.

Bone grafting of the alveolus is an essential step in the reconstruction of the orofacial cleft deformity. Secondary grafting with iliac marrow consistently produces trabecular bone to unify the maxilla and provide odontogenic support. It requires preoperative maxillary alignment, well designed mucoperiosteal flaps, and good oral hygiene to be optimally successful. Its high success rate currently makes it the preferred approach at most centers. Primary grafting with rib results in a unified maxilla, eliminates the oronasal fistula, and does not adversely affect midfacial growth. It assists in preventing maxillary segmental collapse, particularly in the bilateral cleft patient. Whether it can produce enough alveolar bone to support long-term odontogenic needs awaits further clinical documentation in the limited numbers of centers that routinely perform this procedure.

Resorbable fixation techniques for genioplasty.

PURPOSE: This study evaluated the capability and effectiveness of resorbable bone fixation devices in genioplasty surgery. MATERIALS AND METHODS: Twenty patients underwent different genial movements that were stabilized with either 2.5-mm polylactic-polyglycolic acid lag screws or 2.0-mm polylactic-polyglycolic acid plates and screws. RESULTS: Twenty-one anterior mandibular osteotomies were performed in 20 patients. Sixteen patients had advancement (80%), 2 had horizontal setback (10%), and 2 had vertical reduction (10%). The average advancement was 7.6 mm (range, 4 to 14 mm), the average horizontal setback was 6.0 mm (range, 4 to 8 mm), and the average vertical reduction was 7.0 mm (range, 5 to 9 mm). Fixation was done using the lag screw technique in 13 patients (65%) and plate and screw fixation in 7 patients. (35%) Intraoperative stability was satisfactory in all cases. There were no postoperative infections or segmental instability up to 6 months after surgery. CONCLUSION: Resorbable polylactic-polyglycolic acid lag screw and plate and screw fixation is a viable alternative for fixation of anterior horizontal osteotomies of the mandible.

A resorbable and rapid method for maxillomandibular fixation in pediatric mandible fractures.

Maxillomandibular immobilization in pediatric mandible fractures is accomplished through a resorbable screw placed into the zygomatic body to which is attached a large, monofilament, circummandibular suture. Although the screw must be placed intraoperatively, this method of jaw immobilization is rapid, secure, does not damage the teeth, and can be removed in the office in the older child.

Distraction lengthening of the mandibular costochondral graft: a precautionary note.

Distraction osteogenesis of bone-grafted mandibles has been shown to occur without undue difficulties in bone regeneration and healing. In the patient with hemifacial microsomia for which early costochondral graft reconstruction has been done, secondary distraction lengthening may still be needed eventually. It is important to assess preoperatively that the superior portion of the graft is properly positioned against the residual glenoid fossa to prevent excessive superior movement of the proximal mandibular segment during distraction. The case presented clearly illustrates this unique distraction phenomenon.

Zygomaticomaxillary fracture repair with resorbable plates and screws.

The use of nonmetallic plate and screw fixation composed of a resorbable copolymer of poly L-lactic acid and polyglycolic acid (LactoSorb) for the repair of isolated malar fractures was studied in 53 patients. Other than technique variations in application for screw insertion and plate adaptation, no clinical differences were observed in intraoperative bone stability or postoperative long-term results from prior experience with traditional metal devices. No occurrences of postoperative infection, soft-tissue swelling, or maxillary sinusitis occurred in this series with a 6-month to 2-year follow-up.

Resorbable polymer fixation for craniomaxillofacial surgery: development and engineering paradigms.

Advances in medical technology continue to present clinicians with new treatment options for their patients. Frequently, however, a "settling-in" period occurs after initial introduction, during which continued use and experience present new considerations. Absorbable internal fixation has been available in the orthopedic arena for more than a decade, but has been widely available in the craniomaxillofacial arena for only the past few years. Although the major considerations governing its use were obvious initially, since then a set of essential paradigms has presented itself. The authors summarize these principles, providing numerous clinical examples, with the goal of illustrating the current potential of this technology as well as establishing a baseline from which future developments can issue.

Biomechanical testing of resorbable screws used for mandibular sagittal split osteotomies.

PURPOSE: The object of the study was to determine the suitability of specific resorbable screws for fixation of mandibular sagittal split osteotomies by in vitro biomechanical strength testing. MATERIALS AND METHODS: Resorbable screws (2.5 mm diameter) composed of a polylactic acidpolyglycolic acid copolymer were placed in an inverted L-pattern in overlapping urethane blocks representative of sagittal split mandibular surgery. In an in vitro model at room temperature, the test specimens were statically loaded until tensile failure occurred. On a different set of test specimens, dynamic testing was done in an in vitro water bath at body temperature through cyclic loads representative of mastication until failure. RESULTS: In static testing, three 2.5-mm resorbable screws sustained an average peak load of 131 Kiloponds (Kp) (standard deviation, 5.2 Kp) with 5.5% strain at yield. In dynamic testing, the resorbable screws tolerated a 45.3-Kp load for an average of 340,675 cycles (22,783 standard deviation). Several of these test specimens did not ultimately fail and were further evaluated by static testing with an average load of 77.4 Kp until fixation failure occurred. CONCLUSIONS: These laboratory results indicate a relatively high resistance to biomechanical loads representative of mastication and suggest that 2.5-mm resorbable screws of this particular polylactic acid-polyglycolic acid copolymer may be effective in fixation of the postoperative unrestrained sagittal split mandibular osteotomy.

Alloplastic implantation.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Define an alloplastic material and know the differences between an alloplast and other types of implants available for surgical use. 2. Determine the biologic response to alloplastic implantation and the material and host characteristics that contribute to long-term reconstruction success with their use. 3. Review the criteria for choosing a specific alloplastic material for a reconstruction site and the principles of surgical technique for its proper placement. 4. Evaluate the various alloplastic material types that are currently available for surgical use and be able to discuss several physical properties of each as they relate to handling and clinical implantation. 5. Discuss the complication of alloplastic infection, its pathogenesis, preoperative and intraoperative measures for its avoidance, and the postoperative management of its occurrence.