Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “soft-tissue implants”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 217 records · Page 12Linked to original sources

Analysis of silicon in human breast and capsular tissue surrounding prostheses and expanders.

Diffusion of polydimethylsiloxane from silicone breast prostheses and soft-tissue expanders has been associated with capsular contraction. We used electron dispersive x-ray analysis and scanning electron microscopy to assess the presence of silicon in capsular tissue surrounding three categories of breast prostheses and expanders. Breast and subcutaneous tissues external to the capsules were used as control specimens. Semiquantitative results allowed capsules to be ranked according to implant type. Silicon was localized within the inner 2.0 mm of capsular tissue. The analyses of tissues from 2 patients exhibiting unilateral, Baker grade IV contraction after bilateral placement of prostheses showed less silicon present in the severely contracted capsule than in the less-contracted capsule. Results from this study diminish the importance of silicon as the initiator of capsular contraction.

Breast Diseases↗

The management of open fractures associated with arterial injury requiring vascular repair.

Seventy-two open fractures associated with arterial injury requiring vascular repair (Gustilo type IIIC injuries) were treated at the University of Louisville from May 1983 and through 1992. The involved anatomic areas were the humerus (four), forearm (ten), femur (eight), tibia (31), ankle (ten), and foot (nine). Fracture management consisted of careful débridement, wound irrigation, fasciotomy, and fracture stabilization. Additionally, 40 wounds (55.6%) were treated with the supplemental use of local antibiotics (tobramycin-PMMA bead chains). Twenty-three patients (32.1%) underwent primary amputation, and 49 (67.99%) of the injured vessels were repaired. There were seven secondary amputations because of infection or poor revascularization, resulting in an overall amputation rate of 41.6%. The wound infection rate was 13.9% (10 of 72) and the rate for osteomyelitis was 4.2% (3 of 72). The local use of the antibiotic bead chains was of significant benefit in lowering infectious complications. Primary coverage of soft-tissue defects with free tissue transfer had an infection rate of 66%; temporary wound coverage with the "antibiotic bead pouch" technique until wound closure can be obtained in a sterile and viable environment appears to be a better option.

Adolescent↗

Tissue expansion in soft-tissue reconstruction.

Tissue expansion in soft-tissue reconstruction is described. The main principle is to develop donor tissue by expansion adjacent to the defect. Such a donor flap is doubled in size by intermittent injections of normal saline into the expander. After sharing the expanded flap for reconstruction, the donor site is well preserved, while the defect is reconstructed with contiguous tissue of similar texture, color, thickness, and sensation. There is minimal scar formation. Over 130 patients were reconstructed with expanded flaps. The average time of flap development was 3 to 6 weeks.

Adolescent↗

Soft-tissue expansion: concepts and complications.

Soft-tissue expansion complements existing reconstructive techniques and provides new vistas for the plastic surgeon. The technique finds use for overcoming a shortage of tissue, for obtaining skin with special desirable qualities, for creation of flaps otherwise not possible because of the resultant donor site or limited vascularity, for creation of flaps with functioning muscle and overlying soft tissue, and for minimizing flap donor-site problems. Careful planning should include patient counseling, optimum incision placement, and time for a leisurely, complete expansion. The surgery can often be performed under local anesthesia and expansion is tolerated well. Patients should be counseled that the incidence of major complications in an unselected series is 1 in 4 patients. Major complications, however, typically result in a delay in reconstruction and not tissue loss.

Adult↗

Repeated skin expansion to resurface a massive thigh wound.

We report here a patient who sustained posttraumatic skin and soft-tissue loss of the right thigh. Replacement of approximately 750 cm2 of split-thickness skin graft with adjacent skin serially expanded and advanced demonstrates the applicability of this technique to cover large tissue defects. Despite infection and exposure, we believe that expansion can proceed safely on an outpatient basis, providing that systemic toxicity does not develop and the exposure does not mechanically preclude expansion.

Child↗

Use of the temporary soft-tissue expander in posttraumatic alopecia.

Use of temporary soft-tissue expansion in five patients with posttraumatic alopecia and one patient with congenital alopecia is presented. Indications, operative technique, results, and complications are discussed. It is recommended that transpositional and free scalp flaps be expanded prior to transfer, and it is shown that to achieve greater expansion secondarily, the expanders can be reinserted and the scalp reexpanded as needed. The expansion technique provides a quantity of tissue of similar color, texture, and hair-bearing qualities for reconstruction of adjacent defects and makes secondary reconstruction of donor sites unnecessary. After a minimum follow-up of at least 1 year in each case presented, we have determined that the method is safe, simple, and reliable and provides excellent aesthetic results and high patient acceptance and satisfaction.

Adolescent↗

Chest-wall deformity following soft-tissue expansion for breast reconstruction.

We have presented a case in which the presumed pressure effects of tissue expansion caused multiple nondisplaced rib fractures of the anterior thorax in a patient undergoing breast reconstruction. Although the deformity was severe, a satisfactory cosmetic result was obtained and there have been no clinically significant sequelae during a 1-year follow-up period. The degree of bony deformation was most likely enhanced by the combination of this patient's severe osteoporosis, chronic steroid use, and peripheral vascular disease. The fragility and ease of fracture in the bones of osteoporotic postmenopausal females and the long-term effects of steroids on tissues is well known. We believe this observation to be important, since many reconstructed patients are postmenopausal and have variable degrees of osteoporosis. Many undergo adjuvant chemotherapy with steroids and antihormonal agents, and this group of women may therefore be at a greater risk for the occurrence of pressure deformities. The incidence and long-term significance of such deformities are not known. The reconstructive surgeon should be alert to the possibility of this phenomenon occurring as a result of tissue expansion in the patient with severe osteoporosis, peripheral vascular disease, or chronic steroid use.

Breast↗

Soft-tissue expansion in the lower extremities.

Soft-tissue expansion enjoys ever-wider use, but to date an experience using this technique in the lower extremity has never been presented. We reviewed our first 16 patients to describe the indications and contraindications for the use of tissue expansion in the lower extremity. Guidelines evolved from study of the data. Soft-tissue expansion merits consideration for coverage of problem wounds, in preparation for removal of large benign lesions, and for the repair of contour defects. The operator should know that an open wound below the knee predicts a complication if soft-tissue expansion is attempted in that location. In the thigh, incisions can be confidently placed at the edge of the defect. In every location, large expanders should be chosen so that they are as long as or longer than the adjacent defect. The increase in circumference of the limb should be followed. Simple designs for advancement flaps usually work well. As our experience has grown, reconstruction using soft-tissue expansion in the lower extremity has become safer and the results more predictable through better patient selection and diligent monitoring of intraluminal pressures, even if only by ensuring that the patient is always comfortable. Soft-tissue expansion has a role in reconstruction of the lower extremity.

Adolescent↗

Dermal and epidermal response to soft-tissue expansion in the pig.

To evaluate the dermal and epidermal response to soft-tissue expansion in the pig, round tissue expanders were placed dorsally under tattooed patterns and inflated over 6 weeks. Surface area, skin thickness, histologic changes, and collagen content were evaluated at 6-week intervals. Epidermal thickening and dermal thinning were observed. Dermal thinning persisted 36 weeks after expansion. Dermal collagen content was decreased, although collagen density remained unchanged. Total collagen content calculated within an expanded square grid increased. These data support a theoretical gain in the dermal layer as well as epidermal layer in response to tissue expansion.

Animals↗

Use of a calf prosthesis and tissue expansion in aesthetic reconstruction of the leg.

We present a technique for reconstruction of the legs in patients with soft-tissue loss and formation of large scars with retraction of this tissue in the pretibial region. In such patients, a subcutaneous tissue expander is placed in the region adjacent to the scar tissue. With expansion, we obtained sufficient skin for use in the reconstruction, and the resulting asymmetry in leg diameter was compensated for by means of one or two calf prostheses, depending on the patient.

Adult↗

Connective tissue grafting for improved implant esthetics: clinical technique.

The subepithelial connective tissue graft can be used to enhance the esthetic appearance and gingival contour of the peri-implant tissues. A technique is described and illustrated to create a soft-tissue root prominence and mask the grayish color that may be present as a result of a thin facial alveolar bony plate and/or thin labial attached gingival tissue over dental implants.

Connective Tissue↗

Midfacial osteotomies in patients with cleft lip, alveolus and palate.

Surgical/orthodontic strategies in patients with hypoplastic midfaces and cleft of lip, alveolus and palates after completion of skeletal growth are guided by cephalometric data, with the soft-tissue profile playing the most important role. The Le Fort I, the extended Le Fort I and, less frequently, the Le Fort II procedure depend on the extent of midfacial hypoplasia. Osteotomy planning should consider that in cleft patient's maxilla, the anterior nasal spine and A-point need to be advanced and caudally rotated to a larger extent than is necessary in non-cleft patients. A slight overcorrection of ANB-angle is necessary to achieve a harmonious and attractive soft-tissue profile since upper lip and nasal soft tissue require more bony support. In severe bimaxillary disturbances the midfacial advancement has to be combined with mandibular osteotomies. Stabilization after midfacial osteotomies should be done by corrosion-resistant Vitallium or titanium miniplates. This technique provides sufficient stability to restore early function immediately after surgery. Intermaxillary fixation following surgery is no longer necessary. Several decisive advantages are provided by this technique over the previously applied wire suspension concepts or wire suturing techniques. The most advantageous points are: No intermaxillary fixation is required immediately postoperatively; Normal soft food intake is resumed after 8-10 days when wound healing is completed; Rigid plate fixation leads to a considerable improvement in bone healing, while 'pumping-effects' induced by micromovements from the masticatory muscles are avoided; Plate fixation allows immediate functional 'antirelapse-treatment' against relapse tendencies, using functional treatment by means of soft intermaxillary elastics.

Adolescent↗

Prefabricated microvascular autograft in tracheal reconstruction.

Tracheal reconstruction continues to be a challenge in head and neck surgery. Numerous techniques, including the use of alloplasts, composite grafts, and staged laryngotracheal troughs, have met with limited success because of implant exposure, infection, persistent granulation tissue, and eventual restenosis. With recently introduced techniques for soft-tissue molding, bone induction with bone morphogenetic protein, and microvascular free tissue transfer, a rodent model was developed to create a well-vascularized tracheal autograft. In this model, a rigid tube having the same dimensions and flexibility as the native trachea was created by wrapping a cylindrical silicone tracheal mold with a layer of vascularized adductor thigh muscle pedicled on the femoral vessels in the groin. Tracheal rings were created by filing transverse troughs in the muscle bed with bone morphogenetic protein-primed demineralized bone matrix before wrapping around the silicone mold. Grafts harvested at 2 weeks demonstrated rigid skeletal support provided by heterotopic bone formation in the form of rings and a smooth inner lining produced by fibroplasia. Bone transformation was controlled and restricted to the muscle troughs, allowing intervening regions of soft tissue and thus producing a flexible neotrachia. With this model, a homologous, vascularized tracheal autograft capable of microvascular free tissue transfer was fabricated based on the femoral vessels. Prefabrication of composite grafts, through the use of soft-tissue molding, bone induction, and subsequent free tissue transfer, has an unlimited potential for use in head and neck reconstruction.

Animals↗

Ultrasonographic measurement of the soft-tissue of the upper jaw.

For preimplantation diagnoses, various mechanical methods for measuring the width of the soft tissue and thus measuring indirectly the osseous bed of the implant can be used. The ability to determine soft tissue thickness above the jaw by ultrasound was evaluated in 8 autopsy specimens. The data obtained were compared with findings from the needle measurement method which is usually employed in clinical practice. The ultrasound measurement method produced realistic data in all sectional planes chosen.

Anthropometry↗

Induction of new-bone formation in the host bed by human bone-tumor transplants in athymic nude mice.

UNLABELLED: Specimens of twelve osteosarcomas, five chondrosarcomas, one giant-cell tumor, and five extraskeletal soft-tissue sarcomas were transplanted into male athymic nude (nu/nu) mice. Survival of the transplant was determined by the volume-doubling time and the sex chromatin of the tumor cells obtained from two female patients. By these criteria and the similarity of the histological composition of the original tumor and the transplant, survival occurred in four of twelve osteosarcomas and four of five chondrosarcomas. Without any local infiltration of lymphocytes or plasma cells, or other evidence of cell-mediated immunity, the surviving tumors regressed by the fourth week after the operation. Transformed osteoblasts and osteoprogenitor cells were replaced by fibrous connective tissue or fibrogenic tumor-tissue cells. Osteocytes degenerated and disappeared from the lacunae. The one giant-cell tumor transplant survived, growing very slowly, but by the end of the first week after transplantation whorls of mononucleated cells appeared in sites previously occupied by multinucleated cells. Transplants of leiomyosarcoma, liposarcoma, and synovioma (one tumor of each) degenerated. One of two fibrosarcomas survived transplantation. The most striking reaction of the mouse host bed was to encompass six of twelve osteosarcomas and four of five chondrosarcomas in deposits of normal living cartilage, bone, and bone marrow. The incidence of new bone inducedy by living transplants was only slightly greater than by implants of freeze-dried killed osteosarcoma tissue. Not one of five extraskeletal sarcomas, living or dead, induced bone formation. These observations suggest that an osteoinductive agent is transmitted by some osteosarcomas and chondrosarcomas. This agent initiates differentiation of host mesenchymal cells into normal non-tumorous cartilage and bone, which later colonized by bone marrow. CLINICAL RELEVANCE: Our observations present experimental evidence of the origin of the envelope of normal non-tumorous bone that may surround tumorous bone. In 1926, Phemister recognized the clinical significane of this envelope as a pitfall in the differential diagnosis of malignant bone tumors, chondrosarcoma, myositis ossificans circumscripta, and other neoplasms. He emphasized the importance of examining the entire specimen for the distribution of deposits of tumorous and normal bone. The induction of normal bone formation in the host bed surrounding transplants of osteosarcomas and some chondrosarcomas (but not transplants of fibrosarcoma, liposarcoma, or leiomyosarcoma) is evidence of a specific tumor-cell characteristic. Thus, the bone inductive response is not an unspecific reaction to injury from expansion or of tumor growth but a biological response to tumor-cell products. Transplants of human malignant tumors growing in the thymus-deficient mouse can be treated by combinations of radiation, amputation, and new chemotherapeutic agents...

Adolescent↗

Biologic response to uncemented Madreporic canine hip arthroplasty.

The Madreporic hip arthroplasty has provided encouraging clinical results. The surface of the prosthesis is unlike other uncemented prostheses since the rough surface is formed by multiple 1-mm diameter beads that are cast as an integral part of the prosthesis and increase its surface area four times. Seven Madreporic hip arthroplasties were implanted in adult male mongrel dogs. Specimens were harvested 5, 6, 9, 12, 20 and 52 weeks after insertion. One specimen became septic and loosened. The prosthesis was stabilized initially by friction fit between the prosthesis and the endosteal cortex of the proximal femur. Dense, uniformly organized, fibrous tissue surrounded the prosthesis at 5 weeks. The fibrous tissue appeared similar to Sharpey's fibres. Circumferential bone contact increased from 26% at 5 weeks to 60% at 52 weeks. Fluorescent labelling revealed active new bone formation within the interstices of the prosthesis without evidence of an intervening soft-tissue membrane. Firm mechanical anchorage of the Madreporic femoral prosthesis was demonstrated in this study.

Animals↗

The augmentation of soft tissue with injectable collagen.

Clinical experience has demonstrated the value of injectable collagen in treating small soft-tissue defects. Among the lesions that respond best to injectable collagen therapy are nasolabial and glabellar lines as well as areas of atrophy and soft scars. This material is a useful adjunct to surgical procedures and can correct contour irregularities that may follow rhinoplasty or rhytidectomy. The safety of injectable collagen has also been well demonstrated. The nature and incidence of treatment reactions (less than 3 per cent) remains unchanged since the close of clinical trials. Reactions have been localized, and although some have been cosmetically undesirable, none has been health-threatening. All ultimately resolve without therapeutic intervention. Immunologic studies have confirmed the benign nature and specificity of reactions to injectable collagen. The importance of proper injection technique cannot be overstated. Immediately upon injection, tissue blanching followed by whealing and overcorrection should be evident. These indicate the desired superficial placement of the material. The overcorrection helps to compensate for the loss of carrier saline, and it quickly dissipates. When properly injected, injectable collagen can be used safely and effectively to correct an array of soft-tissue contour irregularities.

Antigens↗

A rationale for attached gingiva at the soft-tissue/implant interface: esthetic and functional dictates.

For many years, the ultimate goal of the periodontal/restorative team was to provide an environment for crowns that would provide long-term, successful results. Two essential goals of periodontal therapy were pocket elimination and an adequate zone of keratinized gingiva. The establishment of an adequate zone of keratinized gingiva, which is firmly attached to the underlying periosteum and osseous tissues, is critical for the long-term functional and esthetic results of implant restorative dentistry. Five cases are presented that illustrate the clinical management of soft tissue to achieve functional and esthetic zones of keratinized gingiva.

Adolescent↗