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Biomedical subjects

R P Veth

Publications and source records attributed to R P Veth.

At least 19 recordsLinked to original sources
PubMed1992

Meniscal repair by fibrocartilage? An experimental study in the dog.

Longitudinal lesions in the avascular part of the dog's meniscus were repaired by implantation of a porous polyurethane. Ingrowing repair tissue was characterized by biochemical and immunological analysis. Histologically, repair tissue initially was composed of fibrous tissue containing type I collagen. After 3 months, fibrocartilaginous tissue developed inside the implants, whereas control defects only showed fibrous repair tissue. Both type I and II collagen, the major collagen types of normal meniscal fibrocartilage, could be detected in this newly formed fibrocartilage. It is concluded that fibrocartilage resembling normal meniscal tissue is formed and that longitudinal lesions can be healed after meniscal repair by implantation of a porous polymer.

Animals↗
PubMed1992

The use of the saddle prosthesis for reconstruction of the hip joint after tumor resection of the pelvis.

Reconstruction of the hip joint by a saddle prosthesis after excision of a malignant pelvic tumor is a relatively new method, which thus far has been mainly used for revision of infected hip arthroplasties. One patient with a metastatic cystosarcoma phyllodes and one patient with a chondrosarcoma of the pelvis were treated by local resection and reconstruction with a saddle prosthesis. Although the patient with the metastatic cystosarcoma phyllodes died 9 months after surgery due to metastatic disease, both patients had early recovery, with no difference in leg length and obtained early painless complete weight bearing with satisfactory functional result. These two case reports clearly illustrate the usefulness of the saddle prostheses in limb saving surgery for malignant tumors of the pelvis.

Adult↗
PubMed1992

Quality of life in bone tumor patients comparing limb salvage and amputation of the lower extremity.

In 33 long-term survivors of lower extremity bone cancer quality-of-life data were studied following limb salvage compared to amputation. Self-report questionnaires, semistructured interviews and visual analog scales were used to measure psychoneurotic and somatical distress, activities of daily living, self-esteem, and adjustment to illness. Fourteen patients with limb salvage (age 13-56 years, median 24) and 19 patients with an amputation (age 21-53 years, median 27) were evaluated 2-17 years (median 10 years) after surgery. The differences between the two groups were not statistically significant. However, physical complaints were reported more often by limb salvage patients, whereas the amputees showed a trend toward lower self-esteem and isolation in social life, due to their disability. Both groups felt equal diminution of quality of life and disability as measured on the visual analog scale. These findings could support the cosmetic advantage of limb salvage compared to amputation.

Adolescent↗
PubMed1992

Porous polymer implants for repair of full-thickness defects of articular cartilage: an experimental study in rabbit and dog.

Full-thickness defects of articular cartilage were repaired by implantation of porous polymer implants in rabbits and dogs. The quality of the repair tissue was determined by collagen typing with antibodies. Implants with varying pore sizes and chemical composition were used. The effect of loading and motion was determined by inserting implants higher than, level with and lower than the surrounding cartilage. It appeared that healing took place by formation of fibrocartilaginous repair tissue containing both type I and type II collagen. Hyaline cartilage was observed in a minority of the rabbits used but not in the dog. Fibrocartilage formation in the dog was simulated by implantation of a porous polymer. Chemical composition of the polymer did not alter the results, neither did loading of the implant. It is concluded that the formation of fibrocartilaginous repair cartilage is stimulated by implantation of a porous polymer. This tissue seemed to function adequately in the dog but did show signs of degeneration in the rabbit.

Animals↗
PubMed1992

MRI or CT in the preoperative diagnosis of bone tumours.

The value of magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis of bone tumours was investigated in a prospective study of 25 patients. MRI is superior to CT because it permits multidirectional exposures. Moreover, the tumour can be readily distinguished from the neurovascular structures without injection of contrast medium. MRI gives better contrast than CT, making it possible to study the relationship to the soft tissues, bone marrow and joints more accurately. On the other hand, CT gives a better picture of the destruction of cortical bone. With neither MRI nor CT can the exact tumour length be measured. Neither MRI nor CT permits an exact, reliable diagnosis. Owing to the relatively slow exposure technique in combination with respiratory movements, depiction of the thoracic wall is less satisfactory with MRI than with CT. If both techniques are available, MRI is preferred. In view of the fact that MRI apparatus is still less widely available, it should be borne in mind that CT also allows an adequate investigation of skeletal lesions.

Adolescent↗
PubMed1991

Porous polymer implant for repair of meniscal lesions: a preliminary study in dogs.

Artificial meniscal lesions extending into the avascular part of the meniscus, which do not heal by any other means, were repaired by suturing either a porous polymer implant or a synovial flap into the defect. The implant guided the ingrowth of vascular repair tissue into the defect. This fibrous tissue later on transformed into fibrocartilage. Reconstruction with a synovial flap was not successful. It appeared that healing can be achieved by implantation of a porous polymer implant in a large number of cases. Future research will be aiming at improvement of the results of meniscal repair and application of this type of polymer for repair of cartilage defects.

Animals↗
PubMed1991

IIB osteosarcoma. Current management, local control, and survival statistics--The Netherlands.

Guarded optimism is justified in light of the results of treatment of IIB osteosarcoma in the Netherlands. This is due to improvements in diagnostic imaging techniques, staging, adjuvant chemotherapy, and surgical treatment. Five-year survival rates have increased from 25% to 80%. En bloc resection is currently possible. This makes reconstructive procedure justified, both from an oncologic and orthopedic view. Many questions are still unanswered, concerning evaluation of tumor necrosis because of chemotherapy, optimal adjuvant therapy, functional evaluation of different types of reconstruction, and psychological development of the patient. An international gathering of data on the overall treatment of IIB osteosarcoma is advocated to find answers on the above-mentioned questions. A noninvasive adjustable-lengthening prosthesis is mentioned as a Dutch solution to leg-length discrepancy. This prosthesis can be used after limb-saving surgery in young children.

Amputation, Surgical↗
PubMed1990

[Osteoid osteoma and osteoblastoma].

A follow-up study, based on clinical, radiological and pathological information was performed of 20 patients who had suffered from an osteoid osteoma and of three patients who had been treated for an osteoblastoma in the period 1978-1988. 50% of the patients mentioned both pain at night and a good reaction to salicylates. In 87% of the cases a correct diagnosis was made with the aid of conventional radiography, tomography and bone scanning. Primary treatment consisted of intracapsular (mostly piecemeal) excision in all cases. A local recurrence was observed in one patient with osteoid osteoma and in two with osteoblastoma. At the time of this follow-up study none of the 23 patients had complaints. Histopathological examination did not reveal any difference between the two types of bone tumour.

Adolescent↗
PubMed1990

Pigmented villonodular synovitis.

Pigmented villonodular synovitis is a benign disease of the synovial membrane of joints, tendon sheaths, or bursae, which nevertheless can cause marked local destruction. Its diagnosis is often delayed because complaints and symptoms are nonspecific. Familiarity with the disease may ensure an earlier diagnosis and consequently early onset of therapy, which may prevent serious damage. This paper describes 18 patients suffering from localized or diffuse pigmented villonodular synovitis. Findings possibly suggestive of pigmented villonodular synovitis include hemarthrosis, soft tissue swelling, radiological evidence of cyst formation at a distance from the weight-bearing area of a joint, an increased triglyceride concentration, and a positive bone scan. A normal appearance on arthroscopy does not rule out the disease. Therapeutic results are better in the localized than in the diffuse form of the disease.

Adolescent↗
PubMed1990

An extendable modular endoprosthetic system for bone tumour management in the leg.

A modular endoprosthetic system has been developed at the Groningen University Hospital and the University of Twente. The system can bridge a defect resulting from the resection of a malignant bone tumour which has developed around the knee joint of a child. Since the other healthy leg continues to grow, the system includes an element whose length can be adjusted non-invasively by using an external magnetic field. In addition to this lengthening element, there are one hip and two knee components, connectors of various lengths, and fixation elements. The paper describes the elements of the modular endoprosthetic system. Tables are created by means of which the elemental composition of such an endoprosthesis can be determined for each individual patient.

Adolescent↗
PubMed1989

Megaprostheses in the treatment of primary malignant and metastatic tumors in the hip region.

Twenty patients with malignant bone tumors of the hip region were treated surgically by resection and reconstruction with an endoprosthesis. Histologic types included five primary bone tumors and 15 metastatic lesions. At review four primary bone tumor patients are still alive without evidence of disease. The length of the observation period varied from 26 to 104 months. Eleven patients with metastatic bone disease died. The average postsurgical survival time was 23 months. All patients were able to walk with or without a cane. Failure of an endoprosthesis occurred in one case. According to the Enneking Evaluation System 11 patients had a good and 9 a fair result.

Adolescent↗
PubMed1989

Bilateral total hip and knee replacement in rheumatoid arthritis patients.

Between 1978 and 1983, 14 patients suffering from rheumatoid arthritis were treated by bilateral total hip and knee replacement. At the time of this follow-up study (32-92 months postoperatively) one patient had died of concomitant disease and was excluded. The postoperative results regarding pain relief, improvement in performing daily activities, and function were studied in the remaining 13 patients. A 200-point rating scale was used, which compared the pre- and postoperative findings at follow-up. All patients showed marked relief from pain, good function and a good functional score. Although walking ability did not always improve, all patients were enthusiastic.

Activities of Daily Living↗
PubMed1989

Design of a load cell for the Wagner distractor.

A leg length inequality can be treated by using a Wagner distractor. With this apparatus, it is possible to extend the upper or lower leg slowly. By analysing the measurements of the axial force acting on the femur or tibia the treatment can be optimized and soft tissue damage prevented. To measure the axial force, a load cell has been designed and constructed. This load cell is built into a Wagner distractor and connected with a specially designed measuring amplifier. The load cell and amplifier do not interfere with the lengthening procedure. They are safe for the patient and have an acceptable error of 7 per cent. So far, some test measurements were performed on two patients in the Rummelsberg Hospital in West Germany. The load cell proved to function in a clinical situation.

Adolescent↗
PubMed1989

Design of a lengthening element for a modular femur endoprosthetic system.

A malignant tumour may develop around the knee joint of a child. In the majority of cases it will then be necessary to resect the involved bone with adjacent tissue. A joint team of Groningen University Hospital and University of Twente is currently working on the project of developing a modular endoprosthetic system to bridge the defect resulting from the resection. Since the other, normal, leg continues to grow, the endoprosthetic system will have to include an element the length of which can be adjusted non-invasively. The main conditions to be met by the lengthening element are non-invasive continuous adjustability and a maximum total lengthening of 114 mm. This was achieved by using an external magnetic field. Animal experiments showed that the lengthening element worked well, although moisture infiltrated the telescopic tubes and the lengthening element was covered by proliferating bone at an early stage. Also, the necessary magnetic field proved to be larger than calculated. In a revised design, these problems are resolved. In vitro tests show that the new lengthening element meets all requirements.

Animals↗
PubMed1989

Magnetic resonance imaging (MRI) in evaluating in vivo response to neoadjuvant chemotherapy for osteosarcomas of the extremities.

Limb-saving procedures for patients with osteosarcomas of the extremities are based on the anatomical localization and extent of the tumor. The effectiveness of neoadjuvant chemotherapy, high-dose methotrexate (HD MTX), was prospectively analyzed in patients using magnetic resonance imaging (MRI) and histologic evaluation of bone biopsies. Evaluation of in vivo response to neoadjuvant chemotherapy for osteosarcomas with MRI is a method which seems promising in predicting the histologic tumor reaction.

Adolescent↗
PubMed1986

Eriksson-Ellison reconstructions. The results of a combined intra- and extra-articular procedure for anterolateral instability and a lesion of the anterior cruciate ligament.

A rupture of the anterior cruciate ligament will give rise to the signs and symptoms of anterolateral instability after secondary insufficiency of the lateral capsule and the iliotibial tract have developed. Untreated knee instability predispose to meniscal lesions, chondromalacia, and osteoarthritis of the knee. Other reasons for reconstruction are the patient's wish to return the knee to near-normal function and rejection of life-long utilization of a brace. A combination of an intra-articular Eriksson-Drez procedure and an extra-articular Ellison procedure was carried out in 27 patients with anterolateral instability. Follow-up evaluations were performed, with an average follow-up of 4 years and 5 months. The subjective and objective results are encouraging and similar to those obtained with other combined techniques.

Adult↗