Charles A. Homsy

Experience with a polymer glenoid fossa prosthesis for partial or total temporomandibular joint reconstruction

Glenoid fossa prostheses, alone or in combination with metallic condyles, were placed in 192 joints (127 patients) for temporomandibular joint reconstruction. Anatomic requirements, material characteristics, indications, and surgical technique are presented.

Use of a biocompatible interface for binding tissues and prostheses in temporomandibular joint surgery: Follow-up report

Abstract Nine cases of temporomandibular joint disease requiring surgical reconstruction have been reported. In all instances reconstruction was carried out with the use of a Proplast-coated ticonium prosthesis. Ankylosis was involved in seven cases, and six of these were bilateral. The various problems involved and the reconstruction of the temporomandibular joint are discussed, and the advantages of an acceptable condylar prosthesis are pointed out.

Proplast leader for use in cruciate ligament reconstruction

A synthetic leader has been used in 18 cases of medial one- third patellar tendon substitution for the anterior cruciate ligament and in 10 cases of posterior cruciate substitution using the medial head of the gastrocnemius tendon. The device adds length and facilitates manipulation of the transplanted tissues. There have been no problems with biocompatibility and there have been no instances of staple loosening or disruption of the junction between the stabilizer and transplanted tissues. Early results with the anterior cruciate substitutions suggest that anchoring the transfer in bony tunnels in both the tibia and femur does not allow sufficient flexibility to prevent stretching or disruption of the tendon transfer.

A comparison of porous composite PTFE/graphite and PTFE/aluminum oxide facial implants in primates

Comparison of tissue ingrowth density values for Proplast I and its aluminum oxide analog, Proplast II, when implanted on the primate infraorbital rim and inferior border of the mandible, showed no difference between the two test materials. A similar comparison of local cellular response ratings showed slightly less response to Proplast II. Microscopic and clinical examination did not otherwise reveal any significant differences in biologic reaction to these materials.

Obliteration of traumatically induced articular surface defects using a porous implant

Trauma to articular surfaces penetrating through the subchondral bone can result in areas of incomplete healing. Intraarticular adhesions can originate from these loci of disorganized fibrous bone and cartilage and, along with the incongruous surface, limit motion. In a group of 28 white New Zealand rabbits, 44 standard size defects were created in the prepatellar intercondylar femoral grooves. Twenty-seven were filled with Proplast, a porous implant material. Seventeen were left as controls. The animals were killed at intervals from 3 to 51 weeks. The implant areas were studied grossly and histologically. Granulation outgrowth and adhesions were not seen. From 12 weeks on, normal-appearing hyaline cartilage covered the surface, and bone ingrowth was found within the implant.

Proplast tracheal prosthesis: a preliminary report.

Proplast®, a recently developed biologically acceptable synthetic polymer, has been utilized in replacement of the cervical tracheas of five dogs. The results of this initial study are encouraging and, in the opinion of the authors, justify further experimentation with this refined prosthetic model.

NEW POLYMER GLENOID FOSSA PROSTHESIS FOR TOTAL TMJ RECONSTRUCTION

Publisher Summary Glenoid fossa prostheses have been constructed from cast stainless steel, chrome cobalt, and silicone rubber. The metalic glenoid fossas have been limited in usage because of lack of adaptability during surgery. This chapter presents the brief history, indications, and results of materials used as glenoid fossa prosthesis alone or combined with metallic condyles for total joint replacement in major TM joint dysfunction. These materials are not recommended for temporomandibular joint surgery when more conservative medical and surgical therapy can solve the problem. In major joint dysfunction in which there has been a significant loss of vertical dimension, a new glenoid fossa prosthesis made of Proplast-FEP polymer fabricated from the patients radiographic measurements has been used in 38 joints on 23 patients, since early in 1981. The chapter presents anatomical requirements, material characteristics, indications, operative technique, and results of complications.

Growth of tissue into a porous, low modulus coating on intramedullary nails: an experimental study.

The ingrowth of tissue into a coating of inert, highly porous, low-modulus composite of polytetrafluorethylene polymer and pyrolytic graphite on four-fluted intramedullary nails was used for stabilization of middiaphyseal femoral osteotomies and examined by microangiography. The observations were correlated with information obtained by histologic, microradiographic and tetracycline fluorescence technology. There was rapid healing of the osteotomy. The coating was invaded throughout by blood vessels and fibrous tissue. Invasion by bone was negligible. The composite thus appeared to retain its initial flexibility when implanted into the femoral intramedullary cavity. The force to distract both coated and uncoated nails was measured on intact femora. The unit retention strength increased to an average of 6.3 kg/cm2 up to 24 weeks, which is consistent with reported values. The composite would thus appear to have potential use as a coating for endoprostheses to produce enduring physiologic fixation.

Implantation of a Tissue-Binding Material in the Female Genital Tract: A Preliminary Study on Oviduct Occlusion and the Prevention of Adhesions in Baboons *

Studies conducted in adult female baboons have documented the potential usefulness of a new alloplastic substance, Proplast, when applied to the genital tract of the human female. Two areas of likely application are in the prevention of adhesions in infertility surgery and in reversible or permanent tubal occlusion.