The effects of a soluble polymer and bone wax on sternal healing in an animal model.

Purpose: This study compares the effects of a soluble polymer hemostatic material and bone wax on sternal bone healing.

Description: Median sternotomies were performed on 20 New Zealand White rabbits, and sufficient polymer (Ostene; Ceremed Inc, Los Angeles CA) or bone wax (Bone Wax; Ethicon Inc, Somerville, NJ) was applied to achieve bone hemostasis. After 6 weeks, sternal healing was assessed using roentgenograms, histology, and mechanical strength testing.

Infection rates and healing using bone wax and a soluble polymer material.

The effects of using a newly available water-soluble polymer bone hemostatic material in a contaminated environment were assessed in a rabbit tibial defect model. Infection rates and healing of polymer-treated bone were compared with the infection and healing of bone wax-treated bone and untreated controls after a bacterial challenge. Defects created in 24 rabbit tibias were treated with the polymer or bone wax, or left without a hemostatic agent.

Ostene, a new water-soluble bone hemostasis agent.

Traditional formulations of bone wax are composed largely of beeswax and are well known to interfere with bone healing and cause inflammatory reactions. Ostene, a newly available bone hemostasis agent made of water-soluble alkylene oxide copolymers, was evaluated. The soft tissue response to Ostene was compared with bone wax and a polyethylene control after implantation into the paravertebral muscles of three rabbits.

A new model for heterotopic aortic valve transplantation.

A new model for heterotopic aortic valve transplantation in the rat is described. A composite allograft with an intact aortic valve and partial mitral valve was harvested from 4-month-old (400-450 g) Long-Evans rats and grafted heterotopically into the abdominal aorta of 4-week-old (80-100 g) rats with an optimal size match. At the end of a 1-month observation period, all experimental animals were alive and all showed 100% patency of the aortic valve allografts on microscopic evaluation after death (n=40).

The effects of alloplastic implant onlays on bone in the rabbit mandible.

The relative importance of the factors that contribute to the bone erosion seen underlying alloplastic implants remains unknown. This study was designed to examine the effects of different alloplastic onlays on the mandible in a rabbit animal model. Three alloplastic materials (soft solid silicone, methyl methacrylate, and porous polyethylene) were examined to determine the importance of implant composition in bone resorption.

Modulation of collagen synthesis by transforming growth factor-beta in keloid and hypertrophic scar fibroblasts.

Keloid and hypertrophic scars are fibrous growths characterized by overabundant collagen deposition. We examined the effect of transforming growth factor-beta (TGF-beta), a known stimulant for the production of connective tissue matrices, on the rate of collagen synthesis in keloid fibroblasts (KFs), hypertrophic scar fibroblasts (HSFs), and normal skin fibroblasts (NSFs). Fibroblasts were cultured in three-dimensional fibrin-gel matrices in the presence or absence of TGF-beta (5 ng/ml) or anti-TGF-beta neutralizing antibody (50 micrograms/ml).

Comparison of various delivery systems for demineralized bone matrix in a rat cranial defect model.

Demineralized bone matrix (DBM) has been successfully used as a substitute for bone grafting. Autogenous bone grafts may cause site morbidity and undergo significant resorption. DBM may overcome these problems, but it has no mechanical stability until bone formation has occurred.

External ear reconstruction. Use of a pivoting helix, porous polyethylene implant.

We have used the porous polyethylene, pivoting helix framework for ear reconstruction at RLAMC since 1989 with no major complications. Postoperatively, patients have an external ear that resembles a normal ear and is sturdy enough to support eye wear. The aesthetic results have been well received by the patients and their families (Fig 8).

The natural history of alloplastic implants in orbital floor reconstruction: an animal model.

We developed a new animal model to recreate the condition of an open fracture in communication with the maxillary sinus. We then studied wound healing of the sinus wall structures following fracture in the presence of an alloplastic implant. This model is designed to simulate the alloplastic repair of an orbital floor fracture in humans.

Proximal interphalangeal joint autofusions after extensive burns.

Seven patients with third-degree burns of > 70% of their body had autofusions of 19 proximal interphalangeal joints. In 13 of the joints there was fixed deformity of > 60 degrees. In addition to these deformities, each of the patients had deformities due to burns in the axilla and elbows bilaterally.

The role of alloplastic skeletal modification in the reconstruction of facial burns.

The external appearance of the face is largely dictated by its supporting facial skeleton. After an extensive thermal injury, the underlying facial skeleton may need to be either augmented or restored to maintain the functional and aesthetic appearance of the face. The factors that make a structural reconstruction difficult are poor vascularity and compliance of the scar tissue, extreme contractile forces of the scar, and unstable skin coverage.

The extended deep inferior epigastric pedicle flap for lower extremity reconstruction.

Large soft-tissue defects of the lower extremity can present a challenging reconstructive problem. The extended deep inferior epigastric pedicle flap is a versatile and reliable flap that can be used for the coverage of complex lower extremity soft-tissue defects as far distal as the knee. We reviewed our 5-year experience with 20 consecutive extended deep inferior epigastric pedicle flaps used to cover lower extremity defects.

Reconstruction of the burned external ear using a Medpor porous polyethylene pivoting helix framework.

This paper describes a new technique using a Medpor porous polyethylene pivoting helix framework for reconstruction of the burned auricle. The polyethylene framework is composed of two distinct components, a curved shape that represents the helical rim which pivots around a base component. This framework is covered with a temporoparietal fascia flap and a skin graft that is chosen to match the adjacent resurfaced facial burn.

Clinical experience with the Medpor porous polyethylene implant.

The Medpor porous polyethylene implant is a highly stable and somewhat flexible porous alloplast that has been shown to exhibit rapid tissue ingrowth into its pores. A total of 116 Medpor implants were placed in 70 patients over a four-year period. Implants were used for the chin, malar area, nasal reconstruction, ear reconstruction, orbital reconstruction, and the correction of craniofacial contour deformities.

Craniofacial applications for the Medpor porous polyethylene flexblock implant.

We describe use of flexblock, a newly designed Medpor porous polyethylene implant. This implant is ideally suited for repair of small to medium-sized cranial defects and correction of contour deformities. Medpor is used for a wide variety of maxillofacial procedures, and its properties make it an excellent choice for the cranium.

Coverage of bilateral lower extremity calcaneal fractures with osteomyelitis using a single split free gracilis muscle transfer.

A case is presented in which a single gracilis muscle was split and used for free-tissue coverage of two sites in a patient with bilateral calcaneal fractures and posttraumatic osteomyelitis. Muscle-flap coverage of osteomyelitis and the use of the gracilis muscle for free-tissue transfer are discussed.

The ear model: an aid for total ear reconstruction.

An ear model can be useful in portraying the three-dimensional relationships of the components of the external ear. The role of such a model available as an aid during the carving of a cartilaginous framework in total ear reconstruction is discussed, and a simple method of making an ear model is presented.

The treatment of cutaneous vascular lesions with the Nd:YAG laser.

The Nd:YAG laser is well suited for the treatment of cutaneous vascular lesions. The characteristic properties of the Nd:YAG laser emissions in tissue are a high degree of penetration with low absorption by unpigmented tissue. The result is a coagulative effect on tissue containing hemoglobin with relative skin sparing.

The effects of unilamellar perichondrial dissection on the growth of rabbit ear cartilage.

The effects of elevation of the perichondrium from a surface of growing ear cartilage were investigated in immature rabbits. Eight 21-day-old rabbits completed the study in which perichondrium was elevated from one cartilaginous surface of one ear and the nonoperated ear served as a control. By maturity, both ears had developed symmetrically and no statistically significant difference could be demonstrated in length and surface area.