PubMed HealthSearch

SEARCH · PubMed Health

Results for “Ossicular Prosthesis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

[Histological studies of the behavior of the dentin ossicular prosthesis in the human middle ear].

The Dentine Ossicular Prosthesis (DOP)--introduced in the ENT-Department, University of Hamburg in 1986--has proved its worth clinically in more than 300 cases. In the meantime six of the prostheses had to be removed for various reasons. They had remained in the middle ear over a period between 2-5 and 47 months. The prostheses were investigated undecalcified by the Donath sawing and grinding technique. Prostheses in a nearly bland surrounding show a partial invagination in fibrous connective tissue without severe reaction of the prosthesis itself, whereas in prostheses removed from the neighbourhood of inflammatory processes or recurrent cholesteatoma a partial resorption of dentine with subsequent new bone formation could be observed. Due to the trouble-free clinical and histological performance in the human middle ear, the Dentine Ossicular Prosthesis can be well recommended as an alternative material in ossiculoplasty.

Adolescent

Comparative study of the clinical results obtained by means of Plastipore and ceramic ossicular prosthesis and bone allografts.

We present a comparative study of the clinical and audiologic results obtained by means of Plastipore and ceramic ossicular prostheses and bone allografts in reconstructive middle ear surgery. We stress the excellent tolerance for ceramic and bone allografts in comparison to Plastipore. Functionally, the best results were obtained with partial prostheses using bone allografts and with total ceramic ossicular prostheses. Air-bone gaps less than 10 dB (37%) and 20 dB (69%) were achieved in patients with partial prostheses; in patients with total prostheses, 38% had an air-bone gap of less than 10 dB and 62% of less than 20 dB.

Biocompatible Materials

Experience with a polyethylene total ossicular replacement prosthesis.

Surgical reconstruction of ossicular defects in chronic middle ear disease is a difficult problem. We have reviewed our results with the use of the Plastipore total ossicular replacement prosthesis (TORP). Of 29 procedures that were analyzed, nine were considered successful. None of our patients had a stapes superstructure, and 13 had no malleus. Placement of the TORP under the malleus handle and use of extra tissue between the prosthesis and the tympanic membrane provided better hearing results, but extrusion of the prothesis still occurred. Positioning of the prosthesis and contraction of the middle ear space, which causes extrusion of the prosthesis, remain problems in this type of reconstruction.

Adolescent

Ossiculoplasty failure with ceramic ossicular replacement prosthesis.

The stability of ceramic ossicular replacement prosthesis (CORP) in the middle ear was evaluated in 162 ears that had been followed for more than 18 months. The CORP extruded from 8 ears (4.9%) and was dislocated in 6 ears (3.7%). These failures were considered to be due mainly to postoperative tubal dysfunction and disease recurrence. CORP should not be used when such conditions can be anticipated.

Adolescent

Design and development of a contoured ossicular replacement prosthesis: clinical trials of 125 cases.

A columellar ossicular replacement prosthesis has been developed to simplify ossiculoplasties. The hydroxylapatite head has flattened egg-shaped contours set on a teflon shaft. One hundred and twenty-five prostheses have been implanted and the results of eighty-two cases between five and eighteen months' maturity are presented. Sixty-six percent of good risk partial ossicular replacement prosthesis (PORP) cases achieved air-bone closure within ten decibels and eighty-five percent within twenty decibels. Of all total ossicular replacement prosthesis (TORP) and PORP cases, 51.5 percent closed to within ten decibels and 69.5 percent to within twenty decibels. The design has simplified the preparation and implantation techniques and the prosthesis can be used in most ossiculoplasty situations. A malleus handle is not required and interposition of cartilage is unnecessary. The simplicity of the prosthesis should provide particular benefits for the occasional or trainee otologist.

Clinical Trials as Topic

A universal ossicular replacement prosthesis: clinical trials of 152 cases.

An ossicular replacement prosthesis is described that advances implant design in several respects. The head is a flattened egg shape, which eliminates pressure points against the pars tensa and provided balance on the stapes. Dense hydroxylapatite ceramic provides maximal biocompatibility. The shaft, of either Teflon or Plastipore, is easily cut to size and is replaceable to minimize wastage. Interchangeable partial or total shaft variants are provided. Trials in more than 200 patients have produced optimal results. Among 152 mature patients in 85% of the good-risk cases, the air-bone gap closed to within 20 dB and in 65% to within 10 dB; in 69% of all cases the gap closed to within 20 dB. Extrusion rates were 5% in good-risk cases and 7% overall. Long-term extrusions have not occurred. Inasmuch as cartilage interpositioning is unnecessary, the prosthesis is rapidly prepared and implanted by an easily mastered technique.

Bone Conduction

Long-term observations on ceramic ossicular replacement prosthesis (CORP).

Long-term observations on the ceramic ossicular replacement prosthesis (CORP) were performed. Extrusion rates were 8.3% for CORP-P and 5.2% for CORP-T, with most extrusions occurring within 2 years. Hearing results were satisfactory. Air-bone gaps at 1 year were within 10 dB in 44.8% with CORP-P and 31.2% with CORP-T. At 3 to 5 years, air-bone gaps were within 10 dB in 42.2% and 33.3%, respectively. It was found that the short-term results were maintained even for the long period. Unsatisfactory hearing gains were caused mainly by the displacement or extrusion of CORP which could be prevented by fixation with the cartilage plate, deepening of the base of CORP-P, fixing of the base of CORP-T with the fascia, and additional fixing with the malleus handle and chorda tympani nerve.

Ceramics

Soft tissue reaction to ceramic ossicular replacement prosthesis.

Soft-tissue reaction to ceramic ossicular replacement prostheses (CORP) has been evaluated histologically in rabbits and humans. One week after implantation, severe inflammatory and foreign body reaction was observed in the fibrous connective tissue surrounding the prosthesis. Though some inflammatory response was seen after one month, after three months the CORP was surrounded by a layer of fibrous connective tissue without any foreign body giant cell, histiocyte or inflammatory cell infiltration. Our satisfactory clinical results in humans without placing a cartilage between the CORP and the fascia graft may be due to the excellent soft-tissue compatibility of CORP, as demonstrated in this study.

Aluminum

Use of tragal cartilage with the total ossicular replacement prosthesis.

A method was developed for the use of tragal cartilage and perichondrium with the total ossicular replacement prosthesis. The method involves securing the flat base of the prosthesis in a perichondrial tunnel on the cartilage to stabilize the prosthesis, prevent extrusion, and promote vascularization.

Cartilage

Aluminum oxide ceramic ossicular replacement prosthesis.

Two different prototypes of columella materials made from aluminum oxide ceramics were newly designed by the author for ossicular reconstruction. CORP-P (ceramic ossicular replacement prosthesis-partial) is used as a columella to fit onto the stapes head, and CORP-T (ceramic ossicular replacement prosthesis-total) is used as a columella placed onto the footplate of the stapes. In addition to the general properties of ceramic implants, CORP has these two characteristics: the unique shape of its head, which allows easy and smooth contact with the fascia graft, and the radiopacity, which makes it possible to confirm the position of the implants by x-ray examination after implantation.

Aluminum Oxide

Long-term histologic study of a new carbon-carbon ossicular replacement prosthesis.

In a variety of structural forms, carbon possesses certain properties that render it suitable for implantation in the human body. This report analyzes biocompatibility of a new carbon-carbon prosthesis following long-term middle ear implantation in a prospective, controlled animal study. The prosthesis was placed in the left ear of 20 healthy guinea pigs and in the dorsal subcutaneous tissues for control. The right ear also served as control. Preoperative and postoperative auditory evoked potentials were recorded and compared. Samples of tissue from all three sites were evaluated at 3 and 6 months by light microscopy. The implants also were evaluated by scanning electron microscopy. Samples of lymph nodes, liver, spleen, and lungs also were examined. Fourteen animals (70%) demonstrated no change in auditory evoked potentials postoperatively. One animal developed unilateral dysfunction and three others developed bilateral dysfunction for unexplained reasons. No significant tissue destruction or inflammation of the tissues and no digestion or erosion of the implants were observed. No passage of carbon particles into the reticuloendothelial system was identified. These preliminary results suggest that this new carbon-carbon prosthesis may be biocompatible at 6 months follow-up in the guinea pig and encourage further investigation.

Animals

Plastipore total ossicular replacement prosthesis.

In those ears in which the incus and/or malleus are missing or not suitable, a columella made of high density polyethylene sponge has proven to be very effective. Tissue readily grows into the large pores of this material so that it is well tolerated in the body. During the last six months 54 have been implanted with no rejection so far and a good hearing gain in 43 or 80 percent.

Biocompatible Materials