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Biomedical subjects

R P Veth

Publications and source records attributed to R P Veth.

At least 73 records · Page 4Linked to original sources
PubMed1994

Chondrosarcoma of bone: oncologic and functional results.

A retrospective review of 27 patients (21 males and 6 females) with chondrosarcoma of bone was performed to evaluate the oncologic and functional results. The average age of the patients was 48 years (range: 17-76). The tumor sites were pelvis in 10 cases, distal femur in 2, proximal tibia in 3, rib in 2, and other in 10. One patient with Ollier's disease had chondrosarcoma at two different sites simultaneously. Surgical stages were I A in 8 cases, I B in 8, II A in 1, and II B in 10. Two patients had no surgical treatment. Amputation was performed in 5 cases and en bloc resection in 20. An uncontaminated radical or wide surgical margin was achieved in 13 of 25 cases. Additional surgery was performed in seven cases; for deep infection in one case and for local recurrence or metastasis in six. Local recurrence developed in seven patients (26%). At follow-up, four patients had died of disease (15%), one patient had died of another cause, and two patients were alive with disease (7%). No evidence of disease was found in 20 patients (74%). The oncologic results of limb salvage and amputation in chondrosarcoma of the limbs were good, although there was one failure of limb salvage, caused by infection. Due to surgical inaccessibility, results of the management of chondrosarcoma of the pelvis were poor. The average functional evaluation of 16 patients (average follow-up: 104 months) was 75% (range: 30-100). The Musculoskeletal Tumor Society ratings were excellent in four cases, good in seven, fair in four, and poor in one.

Adolescent↗
PubMed1994

Giant cell tumor of bone: oncologic and functional results.

Giant cell tumor of bone is a challenging surgical problem due to its mostly aggressive growth with tendency to recur locally, to develop in rare instances pulmonary metastases without histologic evidence of malignant changes, and due to its potential to dedifferentiate into a frankly malignant tumor in a limited number of patients. It is treated in many different ways because of the difficulties in finding a type of treatment with the best functional results without compromising oncologic results. This paper describes 19 patients with giant cell tumor of bone. Following 19 procedures (including 6 intracapsular resections [curettage]) in 17 patients in our hospital only 2 recurrences (10.5%) occurred, both after curettage. Functional results after curettage without recurrence were favorable. Marginal or wide resections did not result in any recurrence, but were functionally inferior to curettage; an exception to the latter was the resection-arthrodesis of the distal radius in one patient.

Adult↗
PubMed1994

Severe osteomyelitis due to the zygomycete Apophysomyces elegans.

We describe a previously healthy 69-year-old man presenting with osteomyelitis of the humerus due to the zygomycete Apophysomyces elegans. The infection was acquired in Aruba, The Netherlands Antilles. The skin provided the most likely portal of entry, although there was no history of a traumatic inoculation. The patient had no history of diabetes, and no underlying immune defects were found. Despite treatment with 7.9 g of amphotericin B, an interthoracoscapular amputation proved necessary to curtail the rapid spread of the fungus in this immunocompetent host.

Aged↗
PubMed1994

Development and test of an extendable endoprosthesis for bone reconstruction in the leg.

A malignant bone tumour may develop in the femur of a child. In the majority of cases it will be necessary to resect the bone involved, growth plate and adjacent tissues. A modular endoprosthetic system has been developed which can be extended non-invasively to bridge the defect resulting from such a resection. Elongation is achieved by using an external magnetic field. In vitro tests with a prototype showed that the lengthening element met all requirements. Six animal experiments showed that the lengthening element also functioned in vivo.

Animals↗
PubMed1993

Porous implants for knee joint meniscus reconstruction: a preliminary study on the role of pore sizes in ingrowth and differentiation of fibrocartilage.

Implants with four different macropore sizes were implanted in the meniscus of 29 rabbits for assessment of ingrowth and differentiation of fibrocartilage. Implant macropores were 50-90, 90-150, 150-250 and 250-500 mum, the vol.% macropores was 48-55 and total pore volume 84-86 vol.%. Ingrowth was optimal in the two large pore implants whereas the small pore implants partially remained empty up to 1 year post-operative. Capsule formation and the foreign body reaction was severe for the small pore implants whereas this occurred to a lesser extent in the two large pore implants. Fibrocartilage formation, as assessed by morphology and antibody labelling for type I and type II collagen, was observed in a similar way in all implant types. It is concluded that for optimal ingrowth and incorporation of partial or total meniscal prosthesis, macropore sizes must be in the range of 150-500 mum.

Animals↗
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↗