Biomedical subjects

R P Veth

Publications and source records attributed to R P Veth.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Beneficial effects of cryosurgical treatment in benign and low-grade-malignant bone tumors in 120 patients].

BACKGROUND: Benign and low-grade malignant bone tumours are generally treated with intralesional curettage. At microscopic level tumour cells are left behind and may be responsible for a recurrence. Therefore adjuvant local treatment is necessary. METHOD: By spraying liquid nitrogen into the remaining cavity, tumour cells are frozen very rapidly. Ice crystals formed in the (tumour) cell will mechanically damage the cell resulting in cell necrosis. This combined treatment of surgery and freezing is called cryosurgery. RESULTS: In 120 patients with a follow-up of at least 1 year the treatment results were good. The tumours were: aneurysmatic bone cyst (n = 32), simple bone cyst (n = 13), chondroid tumour (n = 43), giant-cell tumour (n = 13), eosinophilic granuloma (n = 7) and monostotic fibrous dysplasia (n = 12). There were 10 recurring tumours, some of them very small; 6 recurrences were treated successfully by cryosurgery again; in 2 recurrences marginal resection was carried out; 2 recurrences remained (as yet) untreated. CONCLUSION: Cryosurgery as a therapy of benign and low-grade malignant bone tumours yields results nearly as good as marginal resection, and has the advantage that segmental bone resections, which need extensive reconstructions are avoided.

Adult↗

PubMed1999

Osteosarcoma: oncologic and functional results. A single institutional report covering 22 years.

BACKGROUND AND OBJECTIVES: The oncologic and functional results in patients treated because of osteosarcoma (OS) were evaluated. METHODS: Fifty-one patients with high-grade OS were treated between 1974 and 1996 at our hospital. All patient records were studied, and the surviving patients were evaluated according to the American Musculoskeletal Tumor Society functional rating system. The majority of patients received adjuvant chemotherapy (prior to 1983) or neoadjuvant chemotherapy (from 1983). Until 1987, all patients with extremity OS had ablative surgery; from 1987, the majority had limb-saving surgery. Lung metastases were resected in most cases. RESULTS: Overall 2-year and 5-year disease-free survival (DFS) rates were 27 of 51 and 16 of 42, respectively. Patients with vertebral or pelvic OS or contaminated margins after resection had a very bad outcome. In all other subgroups, including patients with various types of chemotherapy, response to chemotherapy, diameter of tumor, presence or absence of metastatic spread, and location of tumor, a 5-year DFS of about 50% was found. Recurrent disease in patients who had achieved a 2-year disease-free interval was relatively low (4/23 patients). CONCLUSIONS: Survival in our series was worse than in most other studies. A very bad outcome was found in patients with vertebral or pelvic OS or with contaminated margins after resection.

Adolescent↗

PubMed1999

Diffuse and localized pigmented villonodular synovitis: evaluation of treatment of 38 patients.

We performed a retrospective study of 38 patients with pigmented villonodular synovitis (PVNS) to evaluate the treatment and functional results. The mean age of the patients was 32 (range 12-72) years at the time of treatment. Three types of PVNS have been identified: localized nodules in 9 patients, diffuse PVNS of the entire synovial membrane in 26, a combination of a diffuse involvement of the synovial membrane and an extra-articular presentation in 1, and extra-articular lesions in 2. The location of the lesions was knee (n = 31), hip (n = 3), ankle (n = 2), femoral triangle (n = 1), and gluteal region (n = 1). The procedures performed were surgery alone, surgery combined with radiosynovectomy and radiosynovectomy only. A follow-up was done after a mean of 4 (range 1-19) years in 34 patients. A functional evaluation according to the Musculoskeletal Tumor Society was performed in 31 patients. The mean functional evaluation score of 34 patients was 24 (range 15-30). Most of the ratings were excellent or good, in 6 cases fair, and in 2 cases poor. This study demonstrates that the functional results are good despite residual or recurrent disease; in addition, we showed that functional evaluation after treatment gives an optimal view of the impact and results of the operation.

Adolescent↗

PubMed1999

Cryosurgery in long bones; an experimental study of necrosis and revitalization in rabbits.

Cryosurgery is an established adjuvant treatment of bone tumors which reduces the local recurrence rate. In this study, cryosurgical experiments were carried out in rabbits to study the temperature field, the extent of necrosis, and the revitalization process in order to optimize treatment. Intramedullary freezing of long bones with a closed liquid nitrogen cryoprobe and three consecutive sessions induces osteonecrosis down to the -10 degrees C isotherm without compromising the soft tissues. The application of a tourniquet does not influence the thermodynamics. The revitalization process is distinguished into an osteogenic and a remodelling phase. In rabbits, there is an obvious periosteal osteogenesis starting from 1 week after operation and overlapping the remodelling phase, which starts between 3 and 5 weeks after operation. Two out of eight rabbits sustained a pathologic fracture within 3 weeks of cryosurgery. No pathologic fractures were encountered during the remodelling phase, probably because of the profuse periosteal bone apposition that added mechanical strength. In clinical practice, no profound periosteal bone apposition and a high risk for pathologic fractures during the remodelling phase were noted. Future research should focus on bone strength during the remodelling phase of cryosurgically treated long bones, to decide on the role of preventive osteosynthesis or postoperative restrictions. This animal model is not advised for these biomechanical experiments because of its profuse periosteal bone apposition.

Animals↗

PubMed1999

Resurfacing potential of heterologous chondrocytes suspended in fibrin glue in large full-thickness defects of femoral articular cartilage: an experimental study in the goat.

A large full-thickness articular-cartilage defect was created in the medial femoral condyle of 32 adult goats. The defects were xenografted with isolated rabbit chondrocytes suspended in fibrin glue. Sham operated goats, where only a standardized defect was created, were used as controls. Results of cartilage repair were assessed after 3, 8, 13, 26 and 52 weeks. The repair tissue was evaluated macroscopically, histologically and biochemically. Results indicated that xenografted rabbit chondrocytes survived the transplantation and maintained their potential to produce matrix in fibrin glue, particularly if they were located in a non-weight-bearing area. In terms of an immunological reaction to xenografted chondrocytes, only mild signs of synovitis were observed in both groups and rejection of transplanted cells did not occur. From 3 weeks gradually progressive resolvement of the fibrin glue was observed with subsequent replacement by fibrous tissue. Initially xenografted defects histologically showed better tendency for cartilage regeneration, however, 52 weeks after surgery no significant differences could be detected in the repair tissue of both groups macroscopically, histologically and on biochemical scoring. The amount of collagen type II in the newly synthesized matrix was 75% 1 year after surgery. This study shows that isolated heterologous chondrocytes can be used for transplantation in articular cartilage defects, however, fibrin glue does not offer enough biomechanical support to the cells to maintain its function as a three-dimensional scaffold.

Animals↗

PubMed1999

Ring chromosomes in a malignant mesenchymoma.

We report, for the first time, the cytogenetic and molecular genetic constitution of a human mesenchymoma. As in several other soft tissue sarcomas, supernumerary ring and rod-shaped marker chromosomes were observed next to an otherwise normal diploid karyotype. Comparative genomic in situ hybridization and whole chromosome painting experiments revealed that chromosome 1q21-q25 and 12q14-q15 sequences were amplified, and that these sequences resided on the supernumerary marker chromosomes. We assume that, in this malignant mesenchymoma, the observed chromosomal anomalies may be associated with its well differentiated liposarcomatous component.

Buttocks↗

PubMed1999

Acetabular coverage of the femoral head after triple pelvic osteotomy: no relation to outcome in 51 hips followed for 8-15 years.

In developmental dysplasia of the hip in adolescents and young adults, pelvic osteotomies aim to improve acetabular coverage of the femoral head by reorienting the acetabulum. We determined whether acetabular coverage is related to long-term clinical results after triple osteotomy of the pelvis. We used a previously published computer program (Konishi and Mieno 1993) which calculates three-dimensional coverage of the femoral head from plain anteroposterior radiographs. We studied the pelvic radiographs of 51 hips in 43 patients and the results were correlated with studies on clinical outcome (de Kleuver et al. 1997). Total acetabular coverage improved from a mean of 56% to 70%. We did not find a relationship between total acetabular coverage and long-term outcome, nor could we determine an optimal coverage. Reduced coverage of the posterolateral quadrant of the femoral head was related to a reduced score for walking ability (p = 0.03), and therefore care should be taken not to overcorrect the acetabulum forwards when attempting to improve the deficient anterior coverage. We challenge the concept that total acetabular coverage is a prerequisite for a good long-term outcome after triple pelvic osteotomy, and hypothesize that other factors such as the change in load across the hip are probably more important in determining the outcome.

Acetabulum↗

PubMed1999

Femoral bone loss in total knee arthroplasty. A review.

Femoral bone loss in total knee arthroplasty (TKA) is a common feature and is mainly attributed to three etiological factors. Stress shielding causes an "osteopenia" type of bone loss behind the anterior flange and adjacent to the distal aspects of the femoral component. Using dual-energy x-ray absorptiometry, decrease in bone mineral density up to 44% has been measured in these areas. Secondly, polyethylene, cement and metal particles are released by implant wear and may cause the less common "osteolysis" type of bone loss located directly at the anterior and posterior implant-cement-bone interfaces. This type of bone loss occurs mainly in young, male, overweight patients with osteoarthritis. Finally, implant loosening leads to bone loss at the bone cement-implant interface and results in "hollowing out" of the distal femur in a stemmed TKA. Femoral bone loss may be reduced by diminishing the stress-shielding effect, by improving the quality of the polyethylene insert, and by decreasing the rate of implant loosening still further. In revision TKA, femoral bone loss is often underestimated in the preoperative radiographs. Classification of bone loss should be made during surgery, and should be based upon the size of the defect generated and the grade of containment. The choice among cement filling, metal augmentation, custom-made TKA, solid bone grafts, and morsellized bone grafts in reconstruction of bone defects will depend upon the type of bone loss, the bone quality, the surgeon's preference and philosophy, and the availability of grafts and implants.

Absorptiometry, Photon↗

PubMed1999

Femoral bone grafting in primary and revision total knee arthroplasty.

The purpose of this study was to evaluate the clinical and radiographic results of TKA's with morsellized and solid femoral bone grafting. From April 1989 to February 1996, 6 primary and 18 revision TKA's with femoral bone grafting were performed in 22 patients with an average age of 62 years. Eleven knees were affected by rheumatoid arthritis, 10 by osteoarthritis, 2 by osteonecrosis and one by hemophiliac arthropathy. The femoral bone defects were large in 12, medium in 9, small in 3, contained in 10 and uncontained in 14 cases. Reconstruction was done with impacted morsellized fresh frozen trabecular bone grafts in 13 knees, with solid bone grafts in 7 knees and with combined grafts in 4 knees. Twenty-one cases were clinically evaluated at an average of 38 months (range: 9-89 months). The average Knee Society knee score increased by 39 points to 85 points at follow-up. The average functional score increased by 22 points to 48 points. Two cases with solid femoral bone grafts failed due to aseptic loosening. There were no infections. Radiographic follow-up revealed osteopenia around the femoral component in 10 knees. Two knees showed circumferential radiolucency around the femoral stem, and 5 knees had minor radiolucency at the anterior part of the femoral component. Radiographic incorporation was present in 5 of the 6 cases that could be evaluated. Histologic analysis of two biopsies revealed incorporation of the morsellized bone graft. The authors advocate impacted morsellized bone grafting for contained and small-to-medium uncontained femoral bone defects in combination with cemented TKA.

Adult↗

PubMed1998

[One hundred years of orthopedics in the Netherlands. III. Bone tumors].

In the fifties, patients with a malignant bone tumour were treated with radiotherapy, sometimes supplemented by resection, as recommended by the Bone Tumour Committee established in 1953. In the seventies, improvement of imaging techniques and chemotherapy made limb-saving surgery possible. Currently, 70% of patients with a malignant tumour of the locomotor apparatus are treated by limb saving, oncologically justified surgery. The surgical defects can be repaired with the aid of an endoprosthesis, or bone homografting or autografting. Children are often treated with an operation involving 180% rotation of the ankle to function as the knee, combined with a prosthesis. Adults are sometimes treated with this technique, but also with internal ('standard') prostheses and donor bone. The future will have to make clear which technique is to be preferred in which situation. Probably, typing and prognosis of various tumours may improve, leading to better insight into the treatment. Centralization of the treatment of rare tumours may also contribute to improvement of the treatment and its scientific research.

Adult↗

PubMed1998

Revisions of endoprosthetic reconstructions after limb salvage in musculoskeletal oncology.

Of 91 limb-salvage procedures using prosthetic reconstructions because of primary or metastatic bone and soft-tissue tumors 26 revisions were performed in 16 patients. Revision was due to polyethylene wear (9 cases), aseptic loosening (8 cases), recurrent hip dislocation (3 cases), prosthetic stem fracture (2 cases), infection (2 cases), leg length discrepancy (1 case), and traumatic dislocation of a saddle prosthesis (1 case). The follow-up period for tumor control varied from 1.5 to 22 years with a median of 13.5 years. The follow-up period after the last revision operation varied from 0.5 to 12 years with a median of 3 years. At the last follow-up, the functional results had deteriorated compared with after the primary operation in 5 patients and had improved in 2 patients. In the remaining patients, the results did not change.

Adolescent↗

PubMed1998

Pelvic osteotomies: anatomic pitfalls at the pubic bone. A cadaver study.

Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomical consequences of two different approaches to the pubic bone were assessed by performing a triple osteotomy on a series of 12 fresh cadaver hemipelvises. The medial approach through a separate incision over the pubic symphysis was compared with the lateral approach through the incision used for the innominate osteotomy. Although the medial approach appears technically easy, there are several anatomical structures at risk, such as the femoral vein and the corona mortis. The lateral approach is safer, and it is easier to make the osteotomy close to the hip joint. The closer the osteotomy is to the hip joint, the smaller the chance of developing a non-union.

Acetabulum↗

PubMed1998

Chondrocyte-seeded hydroxyapatite for repair of large articular cartilage defects. A pilot study in the goat.

The aim of this study was to evaluate the potential for restoration of a large cartilage defect in the goat knee with hydroxyapatite (HA) loaded with chondrocytes. Isolated chondrocytes were suspended in fibrin glue, seeded on top of the HA, and then the composite graft was implanted in the defect. After transplantation, cell behaviour, newly synthesised matrix and the HA-glue interface were assessed histologically after 2, 4, 12, 26 and 52 weeks. Special attention was paid to the incorporation process of HA in the subchondral bone and interactions between this biomaterial and the fibrin-glue-chondrocyte suspension. Chondrocytes in the glue proved to survive the transplantation procedure and produced new metachromatically stained matrix two weeks after implantation. The glue-cell suspension had penetrated the superficial porous structure of the HA. Four weeks after surgery, islands of hyaline-like cartilage were observed at the HA-glue interface. A layer of fibrous tissue was formed surrounding the HA graft, resulting in a relatively instable fixation of the HA in the defect. This instability of the graft in the defect, possibly together with early weight bearing, resulted in a gradual loss of the newly formed hyaline cartilage-like repair tissue. Progressive resorption of the HA occurred without any sign of active bone remodelling from the host site. One year after surgery part of the defect which extended down to the cancellous bone had been predominantly restored with newly formed lamellar bone. Only small HA remnants were still present at the bottom of the original defect. Resurfacing of the joint had occurred with fibrocartilaginous repair tissue. The absence of adequate fixation capacity of the HA near the joint space resulted in a relative instability of the graft with progressive resorption. Therefore, HA is not a suitable biomaterial to facilitate the repair of large articular cartilage defects.

Animals↗

PubMed1998

Synovial sarcoma: oncological and functional results.

AIM: To evaluate the oncological and functional result of the treatment of patients with a synovial sarcoma. This paper gives a retrospective review of 20 patients (15 male and five female) treated for synovial sarcoma at the Nijmegen University Hospital, The Netherlands. METHODS: The median age of the patients was 30 years (range: 14-71, mean 37 years). RESULTS: The tumour locations were: lower extremity in 12 patients; upper extremity in three; pelvic and groin region in four; and the retroperitoneal space in one. Surgical stages according to Enneking (Clin Orthop 1986; 204: 9-24) were IIA in five cases; IIB in seven; and IIIB in eight. The surgical margin was intralesional in three cases; marginal in three; wide in six; and radical in six. In one case the surgical margin could not be assessed and one patient was not operated. One patient developed a recurrent tumour and one developed nodal metastases. Eight patients who did not have metastases at the time of diagnosis developed metastase during follow-up. Fourteen patients died of metastatic disease; one patient died of diabetes; one is alive with disease; and four presently do not have evidence of disease. CONCLUSIONS: The outcome was poor, especially due to the occurrence of pulmonary metastases. The functional result according to the MSTS was 100% in four patients; in one the result was 93% because of the scar and venous insufficiency.

Adolescent↗

PubMed1998

Treatment of benign and low-grade malignant intramedullary chondroid tumours with curettage and cryosurgery.

AIMS: To shed light on the controversy surrounding the methods of evaluating, staging and final treatment of intramedullary chondroid lesions. Controversy particularly exists for enchondroma and low-grade chondrosarcoma located in the extremities, because their accurate distinction is hampered by their radiographical and histological similarity. METHODS: Since 1991 we have treated 22 patients (mean age: 39.6 years) with 26 lesions (three chondroblastomas, 14 enchondromas and nine grade 1 chondrosarcomas) with curettage, cryosurgery and bone grafting. RESULTS: After a mean follow-up of 26 months no recurrences were observed. Complications consisted of two post-operative fractures, one wound infection and one intraoperative venous gas embolism. All bone grafts incorporated, resulting in full weight-bearing capacity and excellent functional results. CONCLUSION: The usefulness of a combination of curettage and cryosurgery as adjuvant therapy is considered to be equal to marginal resection according to orthopaedic oncological principles. The pre-operative assessment of these lesions and cryosurgical technique is described in detail.

Adult↗

PubMed1998

Three-dimensional displacement of the hip joint after triple pelvic osteotomy. A postmortem radiostereometric study.

Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve acetabular coverage of the femoral head in cases of acetabular dysplasia. We undertook a radiostereometric analysis (RSA) on 6 osteotomized cadaver hips to determine the actual three-dimensional reorientation obtained. The centers of the femoral head were all translated posteriorly between 11 and 41 mm, and distally up to 13 mm. 4 were lateralized up to 8 mm, and 2 were medialized up to 5 mm. All acetabuli rotated anteriorly about the lateral to medial axis (X-axis), and 4 rotated outwards around the distal to proximal axis (Y-axis). The correlations between measurements performed on conventional anteroposterior radiographs and the RSA measurements were poor: variations in the lateral-medial direction ranged from -16 to +6 mm, and in the distal-proximal direction between -10 and +12 mm. The changes in orientations measured will significantly affect the load across the hip joint, since the dimensions of the pelvis change and the moment arms of the muscles, their lengths and lines of action are changed as well. We conclude that, with the procedures presently performed, the loads across the hip joint are bound to change, and that the reorientation can hardly be checked with conventional radiographs.

Acetabulum↗

PubMed1998

Eosinophilic granuloma of bone: results of treatment with curettage, cryosurgery, and bone grafting.

Intralesional instillation of steroids is currently the first choice of treatment for eosinophilic granuloma of bone. However, some lesions fail to respond or are unsuitable for injection therapy due location, pending pathologic fracture, and soft tissue intrusion. The authors treated six patients with these lesion characteristics using curettage, cryosurgery, and bone grafting. After a mean follow-up of 34.3 months, all lesions healed completely, although one femoral fracture occurred 8 months after the operation. In selected cases of eosinophilic granuloma of bone, a primary surgical treatment seems feasible. The use of cryosurgery as adjuvant treatment extends the surgical margin and is of value in averting local recurrence.

Adult↗

PubMed1997

Operative management of impending pathological fractures: a critical analysis of therapy.

BACKGROUND: Evident and impending pathological fractures should be stabilised operatively because patients are in serious pain and debilitated for their remaining life span. METHODS: We evaluated survival and functional results after operative therapy. A retrospective study was conducted concerning 116 patients with 152 impending pathological fractures. RESULTS: Of all operated patients, postoperatively 79% regained walking capacity and 60% required no or only occasional analgesic drugs. Patients operated on for impending pathological fractures showed better functional results, as well as those operated with the additional use of polymethylmethacrylate (PMMA). Prophylactic use of antibiotics reduced the number of infectious complications significantly. The median survival after operative therapy was 15 months. CONCLUSIONS: We conclude that impending pathological fractures should be operatively stabilised, if possible, with the additional use of PMMA because of better functional results.

Adolescent↗