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Biomedical subjects

A van Kampen

Publications and source records attributed to A van Kampen.

At least 37 records · Page 2Linked to original sources
PubMed2003

Effects of twisting of the graft in anterior cruciate ligament reconstruction.

In an in vitro study on six knees from cadavers, the effect of bone-patellar tendon-bone graft twist on anterior knee laxity was measured at different knee flexion angles. A motion and loading rig was used to prescribe the flexion angle, to restrain axial rotation, and to apply 100 N anterior force to the tibia. Roentgen stereophotogrammetric analysis was used to measure the relative anteroposterior position of the tibia and femur. The tibial bone block was cemented in a cylinder that allowed rotation in the bone tunnel. The anterior cruciate ligament was transected and reconstructed with neutral, 90 degrees, and 150 degrees internal twists and 90 degrees and 150 degrees external twists. External and internal graft twists in the reconstruction resulted in significant reductions of anterior laxity, however, at the cost of a more posterior position of the unloaded tibia relative to the femur (anteroposterior-error). The results are explained by the anterior relocation of the graft insertion by twisting the tibial bone block. The inclination angle of the graft in the anteroposterior direction flattens, which could improve the anterior laxity. A consequent side effect is the increase of posterior shift of the tibia relative to the femur.

Aged↗
PubMed2002

Improvement in technique for arthroscopic ankle fusion: results in 15 patients.

We retrospectively assessed time until consolidation, complications, and functional results according to Morgan from the clinical charts and radiographs of 15 arthroscopic ankle fusions. In 11 patients unilateral distraction and crossed screw placement over the fusion area through tibia and fibula were used (group A); in 4 patients a technique of bilateral distraction and parallel screw placement from the dorsal side of the tibia into the neck of the talus was used (group B). In group A there were two cases of insufficient compression at the arthrodesis site, three cases of suboptimal compression, and five cases of malposition of the screws. In all cases in group B good compression and fixation was achieved, and no case of malpositioning of screws occurred. There was nonunion in 3 of 11 patients in group A and in none of the four patients in group B. Time until fusion was 23.3 in group A and 12.5 weeks in group B. Functional results were better in group B. The initial experiences with our technique of bilateral distraction and parallel screw placement are therefore promising. Screw placement is easier and optimal compression and fixation are achieved. We feel that this technique should be considered when performing an arthroscopic ankle fusion.

Adult↗
PubMed2001

Procedural learning in Broca's aphasia: dissociation between the implicit acquisition of spatio-motor and phoneme sequences.

Procedural learning of spatio-motor and phoneme sequences was investigated in patients with Broca's and Wernicke's aphasia and age-matched controls. In Experiment 1, participants performed a standard serial reaction task (SRT) in which they manually responded to a repeating sequence of stimulus locations. Both Broca's and Wernicke's aphasics showed intact sequence learning, as indicated by a reliable response time (RT) cost when the repeating sequence was switched to a random sequence. In Experiment 2, Broca's aphasics and controls performed a new serial search task (SST), which allowed us to investigate the learning of a spatio-motor sequence and a phoneme sequence independently from each other. On each trial, four letters were presented visually, followed by a single auditorily presented letter. Participants had to press one of four response keys to indicate the location of the auditory letter in the visual display. The arrangement of the visual letters was changed from trial to trial such that either the key-presses or the auditory letters followed a repeating pattern, while the other sequence was random. While controls learned both the key-press and the phoneme sequences, Broca's aphasics were selectively impaired in learning the phoneme sequence. This dissociation between learning of spatio-motor and phoneme sequences supports the assumption that partially separable brain systems are involved in procedural learning of different types of sequential structures.

Adult↗
PubMed2001

The human transcriptome map: clustering of highly expressed genes in chromosomal domains.

The chromosomal position of human genes is rapidly being established. We integrated these mapping data with genome-wide messenger RNA expression profiles as provided by SAGE (serial analysis of gene expression). Over 2.45 million SAGE transcript tags, including 160,000 tags of neuroblastomas, are presently known for 12 tissue types. We developed algorithms to assign these tags to UniGene clusters and their chromosomal position. The resulting Human Transcriptome Map generates gene expression profiles for any chromosomal region in 12 normal and pathologic tissue types. The map reveals a clustering of highly expressed genes to specific chromosomal regions. It provides a tool to search for genes that are overexpressed or silenced in cancer.

Algorithms↗
PubMed2001

Single-incision technique misses the anatomical femoral anterior cruciate ligament insertion: a cadaver study.

We examined the arthroscopic appearance of the anterior cruciate ligament (ACL) attachment site on the femur in five fresh-frozen cadaver knees. First, the ACL was cut out, leaving a footprint of ligament-fibers with a length of 2 mm intact. The ACL was consistently found to insert on the lateral wall of the notch. No fibers were found to attach high in the roof of the notch at the 12 o'clock position. Secondly, we tried to reach the anatomical attachment site with a femoral aiming guide through a correctly placed tibial tunnel. This proved to be impossible. The closest position that could be reached was at the margin of the anatomical attachment site. Investigation of the distal femur after complete dissection confirmed these arthroscopic findings. Femoral aiming devices for use through the tibial tunnel aim for an isometric placement of the femoral tunnel, they do not aim for an anatomical position of the graft.

Anterior Cruciate Ligament Injuries↗
PubMed2000

Total knee arthroplasty in patients with inherited dwarfism--a report of five knee replacements in two patients with Morquio's disease type A and one with spondylo-epiphyseal dysplasia.

In Morquio's disease and in hereditary spondylo-epiphyseal dysplasia of longer duration, malalignment, instability and unfavourable anatomy are generally the main surgical problems, but as these patients nowadays do not have a reduced life expectancy, it is worthwhile giving them a functional replacement for their severely deformed and painful knees. We report three patients with inherited dwarfism, in whom a replacement of the knee was performed.

Adult↗
PubMed1999

No effective prophylaxis of heterotopic ossification with short-term ibuprofen.

Ninety-five patients underwent primary total hip arthroplasty and routinely received ibuprofen for 5 days as prophylaxis for heterotopic ossification. This group was compared with a group of 99 patients who received indomethacin for 7 days as prophylaxis. After a follow-up of 1 year, the incidence of heterotopic ossification in the ibuprofen group was significantly higher than in the indomethacin group. The widespread ossification, Brooker grades III and IV, was prevented better by indomethacin than by ibuprofen. We conclude that ibuprofen for 5 days is not effective as prophylaxis for heterotopic ossification after primary total hip arthroplasty.

Adult↗
PubMed1999

Indomethacin for 3 days is not effective as prophylaxis for heterotopic ossification after primary total hip arthroplasty.

Although indomethacin is effective in preventing heterotopic ossification (HO) after total hip arthroplasty (THA) when used for 8 to 14 days, side effects are frequently observed. We conducted a prospective, nonrandomized pilot study of prophylaxis for HO in THA using indomethacin for 3 days. We used a 2-stage design for phase 2 clinical data, based on earlier studies in our department. Our study group consisted of 19 patients, of whom 14 (74%) developed HO; 7 (37%) showed grade 1, 4 (21%) grade II, and 3 (15.8%) grade III according to the Brooker classification. We compared these results with 2 historic control groups; one group received indomethacin for 7 days, and the other group received no prophylaxis. We did not see any reduction of the ossification relative to the group that received no prophylaxis. Indomethacin for 3 days seems not to be sufficient to prevent HO.

Adult↗
PubMed1998

[One hundred years of orthopedics in Netherlands. V. Arthroscopy].

Since the early eighties arthroscopy has become an important part of orthopaedics. Virtually every joint can be examined with an arthroscope. Apart from the diagnostic possibilities, an increasing number of arthroscopically guided surgical operations are possible. Knee arthroscopy can be used therapeutically for many conditions, including meniscal lesions, refractory synovitis, cruciate ligament lesions, tibial plateau fractures and osteochondral defects; in the shoulder it can be applied to lesions of the glenoid lip or the rotator cuff; in the ankle and foot, for osteochondral fractures and creation of an arthrodesis; in the wrist, for treatment of instability, intra-articular distal fractures of the radius and the carpal tunnel syndrome; in the hip, for removal of loose bodies and in the spine, for the performance of discectomy. Advantages over conventional open operations are smaller proportions of complications (< 2%), shorter hospital stay and more rapid rehabilitation. The areas of indication are defined in guidelines issued by the orthopaedic societies themselves; most orthopaedic surgeons follow these guidelines. A possibility for the future is use of laser in interventions on joints.

Arthroscopes↗
PubMed1998

Interobserver variance in diagnostic arthroscopy of the knee.

The diagnostic interindividual variance of 91 German and Dutch arthroscopists has been assessed by the Kappa Cohen interobserver variation analysis using a videotape with three complete knee arthroscopies with different pathologies. Non-pathological conditions show a moderate to excellent interobserver correlation, whereas pathological changes often show very little correlation, especially the synovial membrane of the suprapatellar recess, the cartilage of the femuropatellar groove, and the posterior cruciate ligament. The patella alignment also shows a high interobserver variability. There are no apparent differences between German and Dutch arthroscopists. When comparing arthroscopic findings with other imaging techniques the above results should be taken into account because the use of arthroscopy as golden standard is challenged. Furthermore, these results will influence the meaningfulness of medical expert witness based only on pictures. Also the medical cost balance based on arthroscopic findings has to take into account that a wrong diagnosis is possible and therefore charged wrong.

Adult↗
PubMed1998

Meniscal cysts: detection with high-resolution sonography.

OBJECTIVE: The purpose of this study was to determine the feasibility of high-resolution sonography for the detection of meniscal cysts and associated meniscal tears and for the differentiation of meniscal cysts from other masses at the knee joint. SUBJECTS AND METHODS: Fifty consecutive patients (51 knees) with a palpable mass at the knee joint were examined prospectively using a 7.5-MHz annular array transducer. Mass consistency and location and meniscal integrity were evaluated. Sonographic findings were correlated with surgery (46/51) and histopathology (15/51). Five patients did not undergo surgery. RESULTS: At surgery, 32 masses appeared to be meniscal cysts, whereas 19 were other types of masses. Sonographically, 31 of the 32 meniscal cysts were diagnosed correctly. Sonographic differentiation of the other types of masses from meniscal cysts could reliably be made in 17 of 19 cases; two masses were falsely interpreted as meniscal cysts. Sensitivity, specificity, and accuracy of sonography in the depiction of meniscal cysts were 97%, 86%, and 94%, respectively. The positive predictive value was 94% and the negative predictive value was 92%. Meniscal tears (31/46) and meniscal tears concomitant with meniscal cysts (26/32) were detected with an accuracy of 83% and 88%, respectively. CONCLUSION: Sonography is an accurate imaging technique for the detection of meniscal cysts and associated meniscal tears. Differentiation of meniscal cysts from other cystic and solid masses at the knee joint can be reliably made with sonography.

Adolescent↗
PubMed1997

Hip and knee arthroplasty infection. In-111-IgG scintigraphy in 102 cases.

We studied indium-111-labeled immunoglobulin G (In-111-IgG) scintigraphy for evaluation of total hip and knee arthroplasty infection in 100 patients (102 arthroplasties) where infection was suspected (85 total hip and 17 total knee replacements, 23 of which proved to be infected, all but 2 late infections). The sensitivity of In-111-IgG scintigraphy for infection was 1.0, for hip and knee arthroplasties the specificities were 0.8 and 0.5, respectively. False-positive results for infection occurred in cementless total hip arthroplasties up to 14 months after implantation. Aseptic inflammation due to formation of ectopic ossification and foreign-body response, following wear of the polyethylene socket, was responsible for false-positive results. The images should be read in conjunction with radiographs, which reduces the rate of false-positive results. In-111-IgG is a highly sensitive and fairly specific tool for detecting of late infection of total hip and total knee arthroplasties.

Adult↗
PubMed1997

Excisional biopsy of impalpable soft tissue tumors. US-guided preoperative localization in 12 cases.

We present a technique to facilitate excisional biopsy of impalpable soft tissue tumors. A modified Kopans localization needle is positioned preoperatively under ultrasound-guidance (7.5 MHz). The needle contains a hookwire with an over-bent hook that springs open when protruded beyond the needle tip and anchors the wire in the lesion. The technique was used in 12 patients and facilitated excisional biopsy in all of them.

Adolescent↗
PubMed1997

Evaluation of infections of the locomotor system with indium-111-labeled human IgG scintigraphy.

UNLABELLED: Indium-111-labeled human nonspecific immunoglobin G (111In-IgG) is one of the newer agents suggested for scintigraphic evaluation of infection and inflammation. In this study, the utility of this agent was studied in routine clinical practice. METHODS: A dose of 75 MBq 111In labeled to 2 mg IgG (MacroScint) was administered intravenously in 226 patients with 232 possible foci of infection or inflammation. Imaging was performed 4, 24 and 48 hr postinjection. The results were verified by culture, obtained either surgically (42%) or via puncture (19%) and long-term clinical and roentgenological follow-up (39%). Follow-up data were used in patients of whom the vast majority had a negative work-up, including negative 111In-IgG scintigraphy. RESULTS: All infected total hip (THA) and total knee arthroplasties, focal osteomyelitis, diabetic foot infections, septic arthritis and soft-tissue infections were detected (61 foci). Only one patient with early, low-grade spondylodiscitis was false negative with 111In-IgG. Since 111In-IgG scintigraphy does not discriminate between infectious and sterile inflammation, careful interpretation is necessary in cementless THA up to 1 yr after insertion, uptake only around the neck of the femoral component of a THA, recent fractures and pseudarthrosis, in which uptake may be caused by sterile inflammation and not by infection (specificity for inflammation 100%, specificity for infection of 77%). CONCLUSION: Indium-111-IgG scintigraphy is a very sensitive tool for detection of infectious bone and joint disease. Moreover, when uptake patterns of 111In-IgG, which are characteristic for sterile inflammation, are excluded, infection can be ruled out with a high degree of certainty.

Arthritis↗
PubMed1997

[Interobserver variation in diagnostic arthroscopy of the knee joint. "How really objective are arthroscopic findings?"].

UNLABELLED: We assessed the interindividual diagnostic variance of 39 experienced arthroscopists by the Kappa Cohen interobserver variation analysis using videotapes of eight different patients with different diagnoses. Arthroscopically normal findings showed a relatively acceptable interobserver correlation. Pathological changes, in contrast, often showed very little correlation, especially in the synovial membrane of the suprapatellar recess, in the cartilage of the femoropatellar groove and the posterior cruciate ligament. In patellar alignment there was also great interobserver variation. CLINICAL RELEVANCE: When comparing arthroscopic findings with other imaging techniques the above results should be taken into account. Furthermore, these results will affect the significance of medical expertise based only on pictures. In addition, medical cost billing, which is based on arthroscopic findings, has to take into account that a wrong diagnosis is possible and therefore charges will be wrong.

Adolescent↗