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T J Slooff

Publications and source records attributed to T J Slooff.

At least 37 records · Page 2Linked to original sources
PubMed1997

The repeated sampling bone chamber: a new permanent titanium implant to study bone grafts in the goat.

We developed a repeated sampling bone chamber (RSBC) and tested its suitability for studying various aspects of the bone allograft incorporation process under reproducible nonload-bearing experimental conditions in a large vertebrate. Our chamber is made of commercially pure titanium and is designed to allow bone or tissue ingrowth into a removable hollow inner core. Three chambers per animal were randomly implanted in the tibias of 10 goats and were harvested every 8 weeks. In experiment 1, two chambers were filled with a fresh-frozen structural allograft or a chip allograft, and one was left empty. In experiment 2, all chambers were left empty to measure intra- and interanimal variation. The results were evaluated by histomorphometry. Clinical results of four growth factor experiments also are presented. Using this model, we conducted 60 harvest operations (median, 4/animal; range, 2 to 8). In experiment 1, more soft tissue ingrowth and osteoclasts were measured in the chambers with allograft (P < 0.005 and P < 0.03 respectively). Bone ingrowth was scant, with no significant differences between chip graft, structural graft, and empty control chamber. Thus, the bone graft did not show any osteoinductive or osteoconductive properties. Experiment 2 indicated consistent tissue ingrowth, with greater interanimal variation than variations among the chambers in any goat. Our method forms a means of studying gradual tissue and bone ingrowth into bone grafts. The inherent low amount of bone ingrowth makes this model suitable for studying bone-inductive substances. Repeated sampling in the same animals lowered the intersample variability and reduced the number of animals that were required.

Animals↗
PubMed1996

Biomechanical and histological evaluation of a hydroxyapatite-coated titanium femoral stem fixed with an intramedullary morsellized bone grafting technique: an animal experiment on goats.

To reconstruct femoral intramedullary bone-stock loss in revision surgery of failed total hip arthro-plasties, morsellized trabecular bone grafts can be used. In 14 goats a noncemented hydroxyapatite-coated titanium stem was fixed within a circumferential construction of bone allografts. After 6 or 12 wk, four goats were used for mechanical tests and three for histology. The stability of the stems relative to the bone was determined in a loading experiment with Roentgenstereo-Photogrammatic Analysis (RSA). Owing to two loosenings and two fractures, only one 6-wk specimen and three 12-wk specimens were available for mechanical testing. The prostheses were very stable at 12 wk. The most important movements were axial rotation (maximal 0.17 degrees at 800 N) and subsidence (maximal 0.036 mm at 800 N). After unloading, there was 40-60% elastic recovery. Histological examination showed revascularization and remodelling of the graft in all the specimens investigated. At the graft site, bone apposition and bone resorption had resulted in a mixture of graft and new bone. Bone incorporation was mainly seen in the proximal areas. Graft lysis was evident in the midshaft region and at distal levels around the prostheses.

Animals↗
PubMed1996

Acetabular and femoral reconstruction with impacted graft and cement.

Loosening of primary cemented and noncemented components of total hip arthroplasties always is accompanied by a loss of bone stock. There are several options for reconstruction of the acetabular and femoral defects. The authors' treatment of choice is a standardized cemented revision procedure with tight impaction of morsellized cancellous autograft or allograft chips in acetabular and femoral reconstructions. In this study, the clinical and radiographic evaluation of acetabular defects reconstructed with impacted morsellized allograft femoral heads was described. A cemented cup supplemented with morsellized cancellous grafts and wire meshes in cases of segmental defects was sufficiently stable to allow for complete graft consolidation. After a mean followup of 70 months of 88 hips, 4 cases of clinical failures (including 1 infection) and 6 cases of radiologic failure of the reconstructions were observed, resulting in a failure percentage of 11.4% after 5 years. Autografts and allografts were equally effective. Because the clinical success of the technique also was supported by the results of histologic and biomechanic studies in animals, the authors were encouraged to continue this technique, not only in the acetabulum, but also in the femur.

Acetabulum↗
PubMed1996

Impacted graft incorporation after cemented acetabular revision. Histological evaluation in 8 patients.

We took core biopsies from the acetabulum in 8 patients (at reoperation) after a previous revision with impacted cancellous allograft chips in combination with cement. Except for one biopsy specimen, the graft showed different stages of incorporation. In the specimens taken at 4 months, revascularization of the graft was found. Osteoclasts had removed parts of the graft, while woven bone had formed on the remnants of the graft and in the stroma that was invading the graft. Subsequent specimens showed that this mixture of graft and new bone was in due time remodeled into a normal trabecular bony structure with viable bone marrow that contained little or no remnants of the original graft. The graft-cement interface was present in 4 biopsies taken at 1, 22, 28, and 72 months. The specimen obtained 28 months after revision showed vital bone locally in direct contact with the cement layer; however, a soft tissue interface predominated.

Acetabulum↗
PubMed1996

Nuclear arthrography: combined scintigraphic and radiographic procedure for diagnosis of total hip prosthesis loosening.

UNLABELLED: Radiographic arthrography and bone scintigraphy are common diagnostic procedures used for evaluating total hip prostheses. In this study, both techniques are combined, and nuclear contrast imaging (nuclear arthrography) is added. The efficacy of the procedures is evaluated. METHODS: After intravenous injection of 99mTc-methylene diphosphonate (MDP), standard radiographic arthrography was performed in 105 patients (107 prostheses). The radiographic contrast medium was mixed with insoluble 111In-colloid (5 MBq/20 ml). After completion of the radiographic arthrography, nuclear arthrography was performed, and multiple-view dualisotope images (111In, 247-keV peak only) were recorded. Images were interpreted by superposition of the 111In image and the corresponding 99mTc-MDP image, the latter serving as a landmark for the position of the prosthesis and osseous structures. Findings at surgery were used as the gold standard. RESULTS: In both cemented and uncemented acetabular and femoral components, nuclear arthrography performed better than or equal to radiographic arthrography (70%-90% and 60%-75%, respectively). Nuclear arthrography had higher diagnostic accuracy than 99mTc-MDP images alone. CONCLUSION: Nuclear arthrography is a sensitive technique for detection of loosening of prostheses, offering added value over radiographic arthrography and bone scanning alone, especially for evaluation of the femoral component. Radiographic arthrography remains necessary not only for adequate deposition of contrast agents but also for detailed evaluation of osseous structures.

Cementation↗
PubMed1995

Bone grafting in cemented knee replacement. 45 primary and secondary cases followed for 2-5 years.

From 1989 through 1993, we treated 36 knees in 30 patients by bone grafting (31 tibial and 14 femoral grafts) and a cemented total knee prosthesis. We used 23 morsellized and 22 solid bone grafts. After a mean follow-up period of 3 years, the mean clinical (IKS) knee score was 90. Radiographic signs of incorporation of the tibial bone graft were noted in 28 cases. Of the 8 solid femoral bone grafts, we observed twice a disintegration of the graft.

Adult↗
PubMed1994

Relationship between plasma and bone concentrations of cefuroxime and flucloxacillin. Three different parenteral administrations compared in 30 arthroplasties.

(i) The objective was to determine the range of bone levels of cefuroxime and flucloxacillin achieved after one intravenous (IV) administration of different dosages of cefuroxime and flucloxacillin. (ii) Six groups of five patients participated in the study. The first three groups (A-C) received respectively 1500 mg, 1000 mg, and 500 mg cefuroxime intravenously and the second three groups (D-F) received 2000 mg, 1500 mg, and 1000 mg flucloxacillin intravenously. (iii) Parenteral administration of cefuroxime and flucloxacillin resulted in measurable bone concentrations in all patients. (iv) Large inter-individual variation in bone concentration was observed. (v) The bone concentrations of IV cefuroxime were higher (1500 mg, p = 0.0057; 1000 mg, p = 0.0260) than those of flucloxacillin. The bone concentrations of cefuroxime and flucloxacillin were dose dependent.

Adult↗
PubMed1994

A procedure for the visualization of bone with hydroxyl-apatite coated implants.

A procedure for the histological visualization of the interface between implants coated with hydroxyl-apatite (HA) and bone, and the reaction of bones to the implants, has been developed. Thick sections of bones with HA-coated stainless-steel implants, were investigated with the implant still in situ with routine and (confocal) fluorescence microscopy. The prosthesis-HA-bone interface, bone cells, necrotic and vascularised bone, bone-ingrowth and bone remodelling could be visualised. After removal of the implant from the sections alternative sections were further processed for routine light microscopy, microradiography and detailed fluorescence studies. It appeared that the HA coating was still intact and the integrity of the HA-bone bond was very well preserved. The HA coating layer had the same appearance as after the first inspection with surface microscopy. However, more details were visible. Prosthesis-related and time-related changes in the appearance of the HA layer were detected. The advantage of the procedure is that observations can be made of bone reactions with the prosthesis still in situ, without previous embedding in plastics, and laborous sectioning and/or grinding procedures. Thereafter, sections can be processed for different histological techniques, e.g. immunocytochemistry, routine histology, microradiography, fluorescence microscopy, apparently without imparing the HA coating layer.

Animals↗
PubMed1994

Morsellized allografts for fixation of the hip prosthesis femoral component. A mechanical and histological study in the goat.

To simulate femoral intramedullary bone stock loss in revision surgery of failed total hip arthroplasties, a method was developed using impacted trabecular bone grafts. In 14 goats a cemented total hip arthroplasty was performed, fixating the stem within a circumferential construction of bone allografts. After 6 or 12 weeks, 4 goats were used for mechanical tests and 3 for histology. The stability of the stems was determined in a loading experiment with roentgen-stereophotogrammetric analysis; loads of up to 1.44 times body weight were used. One aseptic loosening was seen with gross movements. In the other cases the most important movements were axial rotations (max. 0.24 degrees under 800 N) and axial translations (max. 0.16 mm under 800 N). After unloading some elastic recovery occurred. There were no differences between the 6 and 12-week groups. Histologically, revascularization and remodeling of the grafts were evident. Bone apposition and bone resorption of the grafts resulted in a mixture of graft and new bone. There was more new bone formation in the 12-week group, but the process was not yet completed. The use of impacted trabecular bone grafts in cases of severe intramedullary bone stock loss seems to be a promising revision technique.

Animals↗
PubMed1993

Impacted cancellous allografts and cement for revision total hip arthroplasty.

We report the results of using impacted cancellous allografts and cement for fixation of the femoral component when revision arthroplasty is required in the face of lost bone stock. In 56 hips reviewed after 18 to 49 months there were few complications and a majority of satisfactory results with evidence of incorporation of the graft. Further study and review are necessary, but the use of the method appears to be justified.

Aged↗
PubMed1993

Plasma and bone concentrations of cefuroxime and flucloxacillin. Oral versus parenteral administration in 20 arthroplasties.

Our objective was to determine and to compare the range of bone levels of cefuroxime and flucloxacillin achieved after oral and intravenous administration in 20 arthroplasty patients, allocated to 4 groups: 1 x 500 mg or 7 x 500 mg oral cefuroxime was followed by 2000 mg Flucloxacillin i.v.; 1 x 500 mg and 7 x 500 mg oral flucloxacillin was followed by 1500 mg cefuroxime i.v. Bone samples of hip and knee were obtained. Oral administration did not result in a measurable bone concentration of any of the antibiotics. Intravenous administration resulted in measurable bone concentrations of both cefuroxime and flucloxacillin, with large inter-individual variations. The bone concentrations of intravenous cefuroxime were higher than those of flucloxacillin, despite the lower dose. Oral pretreatment had no effect on the bone concentrations after intravenous administration. No accumulation of the drugs in bone was observed.

Administration, Oral↗
PubMed1993

Cemented fixation with bone grafts.

Loosening of the acetabular cup in cemented total hip arthroplasty is always accompanied by a loss of bone stock. Acetabular lesions can be reconstructed in several ways. Preoperative planning must be through, and specifically if graft procedures are considered, infection must be ruled out. The treatment of choice is a standardized cemented acetabular revision procedure with tight impaction of morsellized cancellous grafts. The clinical success of the technique is supported by the results of an animal experiment.

Acetabulum↗
PubMed1992

Intramedullary fixation with screwed, conical stems--unsolicited results from animal experiments.

For the purpose of studying bone remodeling around prostheses, a segmental replacement for the goat tibia was designed, using a conical, screw-threaded, hydroxyapatite-coated stem for fixation. Eight goats were provided with the implant, seven of which loosened within 10 days post-operatively, displaying progressive radiolucency and gross rotational motion. The eighth one also loosened radiographically, but developed a stabilizing callus bridge to prevent motion. A second design of similar shape and coating, but lacking the screw threads, was designed and also applied in eight animals. In this case, no loosening occurred in the first 6 weeks post-operatively. It is concluded that the application of screwed intramedullary stems for prosthetic fixation is not a viable concept, because the threads prevent the stem from subsiding and restabilizing when minor initial interface stress-relaxation and remodeling has occurred.

Animals↗
PubMed1992

Perioperative factors associated with septic arthritis after arthroplasty. Prospective multicenter study of 362 knee and 2,651 hip operations.

Perioperative factors associated with late septic arthritis after knee and hip arthroplasties were prospectively investigated. All patients received a short course of perioperative cefuroxime. After a follow-up of 1 year, septic arthritis was diagnosed in 9/362 patients (2.5 percent) after knee arthroplasty and in 17/2651 patients (0.64 percent) after hip arthroplasty. For the knee, factors associated with septic arthritis after arthroplasty were rheumatoid arthritis, wound infection, an unhealed wound, and a painful, limited knee function at discharge from the hospital. For the hip, corresponding risk factors were diabetes, failed fracture osteosynthesis, a breakdown of sterility during operation, wound infection, postoperative urinary tract infection, and an unhealed wound at discharge from the hospital or a difficult rehabilitation course. Reoperation after knee and hip arthroplasty was also clearly associated with a higher incidence of septic arthritis.

Arthritis, Infectious↗
PubMed1992

Diagnosis of bone, joint, and joint prosthesis infections with In-111-labeled nonspecific human immunoglobulin G scintigraphy.

The diagnostic accuracy of scintigraphy performed after injection of indium-111-labeled nonspecific human immunoglobulin G (IgG) was studied in 113 patients with 120 foci of suspected infection in bone (52 chronic and eight acute infections), joints (15 localizations), joint prostheses (37 prostheses), and soft tissue of the locomotor system (eight localizations). All patients also underwent standard three-phase scintigraphy after injection of technetium-99m-labeled methylene diphosphonate. A scan obtained with In-111-labeled IgG was considered positive if focal increasing accumulation was noted over time. In 51 patients (45.1%), the results of scintigraphy were verified with intraoperative cultures, and in 21 patients (18.6%), with needle aspiration. The prevalence of infection was 59%; overall sensitivity, 97%; and specificity, 85%. Use of In-111-labeled IgG enabled correct identification of the presence, site, and extent of infection in 69 of 71 proved foci of infection; 41 of 48 negative studies were correct. Only two infections proved with culture were missed; in both patients, the cultures revealed growth of Staphylococcus aureus in low counts.

Arthritis, Infectious↗
PubMed1991

The effect of the extracorporeal shock wave lithotriptor on bone cement.

For the purpose of studying its applicability for acrylic cement removal during total hip revision surgery, experiments with an extracorporeal shock wave lithotriptor were carried out. High-energy shock waves (HESW) were focussed on discs of polymethylmethacrylate bone cement. The average discharge was 18.1 kV; the number of shock waves 0, 100, 250, 500, 1000, and 2000; the application rate was 85 shocks/min. Macroscopic or radiographic effects were not in evidence. Microscopically, typical lesions in a small concentric focal area with a diameter of 8.5 (+/- 2.5) mm were found. The individual lesions were smaller than 0.1 mm, and displayed characteristic shapes. The area porosity increased with the number of shocks. The maximal area porosity caused by the HESW, measured by quantitative microscopy, was 4% after 2000 shock waves. The lesions were also studied by scanning electron microscopy. It can be concluded that HESW causes only microscopic lesions on the frontal surface of discs of bone cement, and that these lesions are small compared to the pores normally present in bone cement, when applied clinically.

Bone Cements↗