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Biomedical subjects

P I Wuisman

Publications and source records attributed to P I Wuisman.

At least 19 recordsLinked to original sources
PubMed2001

Polyurethane real-size models used in planning complex spinal surgery.

STUDY DESIGN: The application of polyurethane real-size models for planning and performing complex spinal surgery is described. OBJECTIVE: To determine the feasibility of using polyurethane real-size models to plan osteotomies, resections, and designs of custom-made spinal implants in complex spinal surgery. SUMMARY OF BACKGROUND DATA: In selected patients with complex spinal pathology, exact planning of the surgical procedure is not possible using current imaging methods. In these cases, real-size spinal models would be desirable to enhance pre- and perioperative planning by visual and tactile feedback, and to improve the production of custom-made spinal implants. METHODS: A real-size spinal model of six patients was produced from hardened polyurethane foam on the basis of data from contiguous computer tomography slices. In two patients, the models were used to plan correction osteotomies and resections, with the assistance of image-guided surgery in one of the patients. In four patients, the models were used to plan tumor resections and to produce custom-made spinal implants. RESULTS: In all the patients, the surgical procedure could be performed exactly according to the preplanned intervention. The polyurethane real-size models provided essential and additional information by direct visual and tactile feedback. They allowed in vitro testing of custom-made spinal implants with a perfect fit. CONCLUSIONS: Real-size spinal models made from polyurethane foam can be used to provide excellent understanding of the complex spinal pathology in highly selected patients. These models allow complex spinal surgery with a more predictable outcome.

Adolescent↗
PubMed2001

Disorders in trunk rotation during walking in patients with low back pain: a dynamical systems approach.

OBJECTIVE: (1) To introduce an evaluation tool for the assessment of walking disorders in low back pain patients. (2) To investigate whether walking patterns in low back pain patients are different from those of control subjects. DESIGN: Relative phase measures of movement coordination are applied in the assessment of trunk function in a small group of patients with non-specific low back pain and in control subjects. BACKGROUND: Normal subjects change the coordination of pelvic and thoracic rotations from an in-phase to an out-of-phase pattern with increasing walking speed. Low back pain patients may have a reduced ability to counter rotate pelvis and thorax at higher walking speeds (from 1.0 m/s onwards) as a result of hyperstable coordination patterns. METHODS: Six patients with non-specific low back pain and six healthy control subjects walked on a treadmill at comfortable walking speeds and during a systematic variation of the treadmill velocity. Coordination of arm and leg movements as well as of pelvic and thoracic rotations was analyzed using a relative phase algorithm. RESULTS AND CONCLUSIONS: The comfortable walking speed was reduced in the patient group. In contrast to the control subjects, four of the six patients were not able to establish an out-of-phase coordination pattern between thorax and pelvis at higher walking speeds. This coincided with an increased stability of movement coordination, indicating guarded behavior. In addition, an increased asymmetry between the phase-relations of left and right side of the body was found in some of the patients.

Adolescent↗
PubMed2001

Revision knee arthroplasty using impaction grafting and primary implants.

A technique is described for revision knee arthroplasty with impaction grafting of cancellous bone grafts to treat bone loss and the use of primary implants. Specially designed impaction instruments were used. Bone loss was classified according to the Anderson Orthopaedic Research Institute classification. Four-year follow-up of 11 knees in 9 patients showed good clinical and radiographic results.

Aged↗
PubMed2001

Deformities of the shoulder in infants younger than 12 months with an obstetric lesion of the brachial plexus.

We performed a prospective study using MRI in 16 consecutive infants with a mean age of 5.2 months (2.7 to 8.7) who had shown inadequate recovery from an obstetric lesion of the brachial plexus in the first three months of life, in order to identify early secondary deformities of the shoulder. Shoulders were analysed according to a standardised MRI protocol. Measurements were made of the appearance of the glenoid, glenoid version and the position of the humeral head. The appearance of the glenoid on the affected side was normal in only seven shoulders. In the remainder it was convex in seven and bioconcave in three. The degree of subluxation of the humeral head was significantly greater (p = 0.01) in the affected shoulders than in normal shoulders (157 degrees v 170 degrees). The presence of an abnormal appearance of the glenoid, retroversion of the glenoid and subluxation of the humeral head increased with age. There was a statistical difference (p = 0.05) between infants younger than five months and those who were older.

Age Factors↗
PubMed2000

Use of recombinant human osteogenic protein-1 for the repair of subchondral defects in articular cartilage in goats.

The objective of this pilot study was to examine in vivo the potential of recombinant human osteogenic protein-1 (rhOP-1, also called bone morphogenetic protein-7, BMP-7) for treatment of subchondral lesions by induction of new hyaline cartilage formation. Subchondral left knee defects in 17 mature goats were treated with fresh coagulated blood mixed with (1) rhOP-1 combined with collagen (OP-1 device, 400 microgram/mL); (2) rhOP-1 alone (OP-1 peptide, 200 microgram/mL); (3) OP-1 device with small particles of autologous ear perichondrium; (4) OP-1 peptide with small particles of autologous ear perichondrium; or (5) autologous ear perichondrium alone (controls). rhOP-1 was combined with either collagen (OP-1 device) or not (OP-1 peptide). The defects were closed with a periosteal flap. The formation of cartilage tissue was studied by histologic and biochemical evaluation at 1, 2, and 4 months after implantation. One and 2 months after implantation there were no obvious differences between control and rhOP-1-treated defects. Four months after implantation, only one out of three controls (without rhOP-1) showed beginning signs of cartilage formation while all four rhOP-1-treated defects were completely or partly filled with cartilage. A significant linear relationship was found between rhOP-1 concentration and the total amount of aggrecan in the defects. These results suggest that implantation of rhOP-1 promotes cartilage formation in subchondral defects in goats at 4 months after implantation. Therefore, rhOP-1 could be a novel factor for regeneration of cartilage in articular cartilage defects.

Animals↗
PubMed2000

Thoracoscopically assisted total en bloc spondylectomy: two case reports.

We describe a combined surgical technique for tumors of the thoracic spine consisting of a thoracoscopically assisted ventral release followed by a dorsal en bloc spondylectomy and reconstruction. The technique enables thoracoscopic access and release of the involved spinal segment(s) to achieve surgical and histopathologic wide margins, avoiding the disadvantages inherent to thoracotomy. Two patients were successfully treated with solitary tumors involving T10 and T7-8 vertebra. The resection margins were free of tumor. Thoracoscopically assisted total en bloc spondylectomy allows wide excision of thoracic spinal tumors with free resection margins in selected patients; the operation can be performed under direct vision without contamination of uninvolved parts.

Adenocarcinoma, Follicular↗
PubMed2000

Augmentation of (pedicle) screws with calcium apatite cement in patients with severe progressive osteoporotic spinal deformities: an innovative technique.

Screw augmentation with calcium apatite cement (CAC) was used in seven patients with a progressive osteoporotic spinal deformity. Thirty-nine spinal segments (64 screws) were augmented: 15 anteriorly (three patients) and 24 posteriorly (five patients). Dorsally, hemilaminectomy was performed at the level of all augmented screws to rule out CAC leakage. Autogenous bone graft was applied in all patients to induce fusion. Screw augmentation failure occurred in only one patient: 1 of the 16 ventral augmented screws (5.5%) was still loose after the augmentation procedure. In three other patients, 4 out of 48 augmented dorsal screws (5.5%) showed CAC leakage at the pedicle corpus vertebra level. Pedicle wall damage was present at two levels, while at two other levels no wall damage was found during visualization. No CAC-related complications were observed perioperatively. No implant migration was observed, and fusion was observed in all cases at follow-up examination performed at a mean of 32 months after surgery.

Adult↗
PubMed1999

Severe progressive osteoporotic spine deformity with cardiopulmonary impairment in a young patient. A case report.

STUDY DESIGN: This report describes a young patient with a rapidly progressive kyphosis caused by collapse of a severely osteoporotic thoracolumbar spine, which led to impairment of cardiopulmonary function. OBJECTIVES: To highlight the treatment strategy, difficulty of diagnosis, operative stabilization, and outcome. SUMMARY OF BACKGROUND DATA: Little is known about natural history, treatment options, and results of this condition. METHODS: The magnitude of bone loss was measured by dual-energy x-ray absorptiometry, and the deformity was visualized by computed tomography and magnetic resonance imaging. Laboratory investigations also were performed before and during halotraction in an attempt to establish a diagnosis. These data constituted the preoperation information required to assess later results of medical and surgical intervention. RESULTS: An extensive evaluation of possible underlying etiologies failed to identify a specific etiology. Before and during halotraction, bone mineral substitutes were given, partially correcting the bone mineral content as measured on repeated dual-energy x-ray absorptiometry scans. In addition, the thoracic kyphosis was partially corrected, from 100 degrees to 70 degrees Cobb's angle. Subsequently, a combined anterior and posterior stabilization was performed from C7 to S1 using a vascularized fibula graft, a double Isola rod system (AcroMed, Cleveland, OH), and a carbonate apatite cancellous bone cement to reinforce the pedicle screws. At follow-up assessment 40 months surgery, the patient was asymptomatic and fully mobilized, with radiographs showing complete incorporation of the grafts and no loosening of the fixation device. CONCLUSIONS: The diagnostic and therapeutic difficulties of progressive spine deformity caused by severe osteoporosis in young patients emphasizes the importance of a thoroughly planned treatment strategy. Halotraction is recommended to stop progression of the deformity, or even partially correct it, and to allow time to search for the diagnosis and bone mineral substitution. Surgical treatment using vascularized fibular strut grafts and a strong fixation device was successful. Biocompatible carbonated apatite cancellous bone cement was successfully used to reinforce pedicle screw fixation.

Absorptiometry, Photon↗
PubMed1999

Free vascularized bone graft in spinal surgery: indications and outcome in eight cases.

In selected spinal deformities the use of a vascularized graft to establish fusion may be considered: compared to a non-vascularized graft it has superior mechanical properties, resulting in greater graft strength and stiffness, and greater effectiveness in facilitating union. Eight patients with a progressive spinal deformity (four cases) and malignancy (four cases) were treated with resection and/or correction and stabilization. To facilitate (multi)level fusion vascularized fibular grafts were used in two cervical and two thoracolumbar deformities. Fibular (two cases) or iliac grafts (two cases) were used in four cases of spinal reconstruction after vertebrectomy for malignancy. In all patients complete incorporation of the graft was obtained within 5 weeks to 8 months postoperatively. Complications occurred in three cases: one patient had a transient laryngeal edema and laryngeal nerve palsy. Another patient had a non-fatal deep vein thrombosis with pulmonary embolisms, successfully treated with anticoagulants. A third patient developed a lung infection and subsequently a deep infection around the dorsal instrumentation; after hardware removal the infection was controlled. At the latest follow-up (mean 30 months, range 24-48 months) six out of eight patients are alive. One patient died 2.5 years after the intervention due to widespread metastases, while another patient died in the postoperative period due to unknown reasons. Vascularized bone graft in spinal surgery facilitates primary mechanical stability and rapid fusion, and it has higher resistance to infection. The variety of applications of a vascularized graft may extend the range of indications for the use of grafts in spinal surgery.

Adolescent↗
PubMed1999

Recurrent osteoblastoma of the hamate bone. A two-stage reconstruction with a free vascularized iliac crest flap.

An osteoblastoma in a carpal bone is very rare and presents a problem of reconstruction after wide tumour excision. We report a case of recurrent osteoblastoma of the right hamate bone with involvement of the ulnar carpal bones and soft tissues that was successfully treated by en bloc resection, temporary interposition of bone cement and fixation with K-wires, followed by reconstruction with a free vascularized iliac crest flap, tailored to the exact size of the defect, in a second procedure. Rapid fusion was achieved and hand function preserved with no evidence of recurrence 3 years postoperatively.

Adult↗
PubMed1999

Histopathology of retrieved allografts of the femoral head.

From November 1994 to March 1997, we harvested 137 grafts of the femoral head from 125 patients for donation during total hip arthroplasty according to the guidelines of the American Associations of Tissue Banks (AATB) and the European Association of Musculo-Skeletal transplantation (EAMST). In addition to the standards recommended by these authorities, we performed histopathological examination of a core biopsy of the retrieved bone allograft and of the synovium. Of the 137 allografts, 48 (35.0%) fulfilled all criteria and were free for donation; 31 (22.6%) were not regarded as suitable for transplantation because the serological retests at six months were not yet complete and 58 (42.3%) were discarded because of incomplete data. Of those discarded, five showed abnormal histopathological findings; three were highly suspicious of low-grade B-cell lymphoma, one of monoclonal plasmacytosis and the other of non-specific inflammation of bone marrow. However, according to the standards of the AATB or EAMST they all met the criteria and were eligible for transplantation. Our findings indicate that the incidence of abnormal histopathology in these retrieved allografts was 3.6%. Since it is essential to confirm the quality of donor bones in bone banking, we advise that histopathological screening of donor bone should be performed to exclude abnormal allografts.

Adult↗
PubMed1998

Lumbar intervertebral disc involvement in chronic lymphocytic leukemia. A case report.

STUDY DESIGN: Report of a patient with a rare location of a solid chronic lymphocytic leukemic mass of an intervertebral lumbar disc. OBJECTIVES: To illustrate the previously undescribed discovertebral involvement of chronic lymphocytic leukemia and to discuss the diagnostic difficulties. SUMMARY OF BACKGROUND DATA: Chronic lymphocytic leukemia primarily involves lymph nodes, spleen, liver, and bone marrow. Bone lesions are rare in chronic lymphocytic leukemia and usually consist of areas of osteopenia. Spinal involvement in chronic lymphocytic leukemia is rare, and only two cases of spinal cord compression attributable to an extradural solid mass composed of leukemic cells have been reported. Intervertebral disc involvement in chronic lymphocytic leukemia has not been reported previously. METHODS: The clinical findings, radiographs, histology, treatment, and follow-up results are presented. RESULTS: Radiographs and magnetic resonance imaging studies showed partial collapse of vertebrae L2 and L3, with destruction and protrusion of the intervertebral disc L2-L3 with dura compression. Treatment consisted of radiotherapy followed by en bloc resection of vertebrae L2 and L3 stabilized with stackable cages and anterior fixation with Kaneda bars. Intervertebral disc infiltration with leukemic cells of B-cell origin was confirmed through histologic examination and immunohistochemical studies of a biopsy and resection specimen. Twenty months after treatment the patient was still in remission and fully mobilized. CONCLUSIONS: Intervertebral disc involvement in cases of chronic lymphocytic leukemia is rare. Its presence should be considered in patients with back pain and neurologic symptoms who had been treated for this form of leukemia in the past. Differentiation with infectious spondylodiscitis can be difficult. Histology is necessary to confirm diagnosis.

Aged↗
PubMed1998

Osteogenic protein (OP-1, BMP-7) stimulates cartilage differentiation of human and goat perichondrium tissue in vitro.

The objective of this study was to examine in vitro the influence of recombinant human osteogenic protein-1 [rhOP-1, or bone morphogenetic protein-7 (BMP-7)] on cartilage formation by human and goat perichondrium tissue containing progenitor cells with chondrogenic potential. Fragments of outer ear perichondrium tissue were embedded in clotting autologous blood to which rhOP-1 had been added or not added (controls), and the resulting explant was cultured for 3 weeks without further addition of rhOP-1. Cartilage formation was monitored biochemically by measuring [35S]-sulphate incorporation into proteoglycans and histologically by monitoring the presence of metachromatic matrix with cells in nests. The presence of rhOP-1 in the explant at the beginning of culture stimulated [35S]-sulphate incorporation into proteoglycans in a dose-dependent manner after 3 weeks of culture. Maximal stimulation was reached at 40 microg/mL (human explants: +148%; goat explants: +116%). Histology revealed that explants treated with 20-200 microg/mL of rhOP-1, but not untreated control explants, contained areas of metachromatic-staining matrix with chondrocytes in cell nests. It was concluded that rhOP-1 stimulates differentiation of cartilage from perichondrium tissue. The direct actions of rhOP-1 on perichondrium cells in the stimulation of chondrocytic differentiation and production of cartilage matrix in vitro provides a cellular mechanism for the induction of cartilage formation by rhOP-1 in vivo. Thus rhOP-1 may promote early steps in the cascade of events leading to cartilage formation and could prove to be an interesting factor in the regeneration of cartilage in articular cartilage defects.

Animals↗
PubMed1998

[Integrated (biopsychosocial) treatment in the family practice: a pregnant patient with a sacral tumor and severe posttraumatic stress disorder].

In a 25-year-old woman pregnant for the second time after a successful first pregnancy, a locally aggressive, invasive sacrum tumour was diagnosed. The execution of the necessary but potentially mutilating surgical procedures was seriously hampered even during the preparative phase, in spite of the conscious wish of the patient to comply, by her severe psychiatric problems (posttraumatic stress disorder with dissociative symptoms). The Psychiatric Consultation Service took over the case management and an integrated (biopsychosocial) diagnostic investigation was carried out, involving analysis of the problems on four system levels: the biological, the psychological, the social and the health care level. An integrated treatment plan was drafted. By collaboration of the entire multidisciplinary treatment team conditions were secured under which patient would let herself be treated. In this way she was enabled to undergo the necessary procedures, with good results.

Adult↗
PubMed1998

Accuracy of the sagittal vertical axis in a standing lateral radiograph as a measurement of balance in spinal deformities.

Sagittal balance of the spine is becoming an important issue in the assessment of the degree of spinal deformity. On a standing lateral full-length radiograph of the spine, the plumb line, or sagittal vertical axis (SVA), can be used to determine the spinal sagittal balance. In this procedure patients have to adopt a habitual standing position with the knees extended during radiographic examination, though it is not known whether small changes in the position of the lower extremities affects the location of the SVA. The purpose of the present study was to investigate the effect of postural change on shifts of the SVA, and to evaluate whether the SVA as measured on a standing full-length lateral radiograph can be used as an accurate measurement of spinal balance in clinical practice. Sagittal balance was analyzed using a patient with ankylosis of the entire spine due to ankylosing spondylitis, to eliminate segmental movement of the spine. A virtual SVA was constructed for seven different standing postures by cross-referring the coordinate systems from a standing full-length lateral radiograph of the spine with video analysis. The horizontal distance between the SVA and the anterior superior corner of the sacrum was measured for each posture. Small changes in the joint angles of the lower extremities affected the SVA significantly, and resulted in the horizontal distance between the SVA and the anterior superior corner of the sacrum varying from -4.5 to +14.9 cm. High correlations were found between this distance and the joint angle of the hip (r = -0.959), knee (r = -0.936), and ankle (r = 0.755) (P < 0.01). The results of the study showed that SVA translations during standing radiographic analysis in a patient with a fixed spine depend on small changes in the hip, knee, and ankle joints. Thus, sagittal spinal (im)balance in ankylosing spondylitis can not be measured from the SVA on a standing lateral full-length radiograph of the spine unless strict procedures are developed to control for the angle of the hip, knee, and ankle joints. The accuracy of the SVA as a measurement of sagittal spinal balance in other spinal deformities, with possible additional segmental movements, therefore remains questionable.

Adult↗