| 1. |
- Mikhail, W. E., et al.
(författare)
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Femoral bone regeneration subsequent to impaction grafting during hip revision : histologic analysis of a human biopsy specimen
- 1999
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Ingår i: The Journal of Arthroplasty. - Philadelphia, USA : Elsevier. - 0883-5403 .- 1532-8406. ; 14:7, s. 849-953
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Tidskriftsartikel (refereegranskat)abstract
- Cemented revision with impaction grafting shows encouraging early clinical results; postoperative biopsy specimens taken from the proximal femur in humans have demonstrated viable trabecular and cortical bone. Human radiographic studies also illustrate density changes within the proximal femur, consistent with remodeling of bone-graft. In an animal experiment, bone incorporation was shown in the proximal femur, but graft lysis was reported around the distal portion of the implant. We report on a patient who sustained a traumatic femoral fracture at the level of the tip of the femoral component 27 months after revision with impaction grafting and a collarless polished taper stem. At the time of open reduction and internal fixation of the fracture, we obtained circumferential biopsy specimens from the fracture site. Three distinct zones could be identified histologically: i) an inner zone consisting of bone-cement, fibrous tissue, and partially necrotic trabeculae with evidence of bone remodeling; ii) a middle zone consisting of viable trabecular bone and probable neocortex formation with fewer particles of bone-cement; and iii) an outer zone with viable cortex. Fibrous tissue was present around some of the incorporating bone-graft fragments, but no continuous fibrous membrane was present. Cement particles were identified, but no polyethylene debris was found by light microscopy. Biopsy specimens from the distal aspect of the prosthesis may not reflect changes seen proximally, but based on the available tissue, this case illustrated histological evidence of bone-graft remodeling after impaction grafting. These results are consistent with our expectations based on radiographic findings and clinical results.
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| 2. |
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| 3. |
- Kesteris, Uldis, et al.
(författare)
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Polyethylene wear and synovitis in total hip arthroplasty: a sonographic study of 48 hips
- 1999
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Ingår i: Journal of Arthroplasty. - 0883-5403. ; 14:2, s. 138-143
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Tidskriftsartikel (refereegranskat)abstract
- Forty-six patients (48 hips), operated on with cemented total hip arthroplasty (THA) because of arthrosis, were examined radiographically and sonographically at 10-year follow-up. Polyethylene wear of acetabular cups was measured on conventional non-weight-bearing pelvic radiographs, and the volume of polyethylene debris was calculated. Radiographic signs of loosening were identified. The capsular distance (ie, thickness of the synovium or synovial contents) was measured sonographically. We found a significant correlation between increased volumetric wear and increased capsular distance. Hips with radiographically loose acetabular components had significantly greater volumetric wear and capsular distance than those without signs of acetabular loosening. This relationship was not observed in hips with radiographically loose femoral components. In cemented THA, the volume of polyethylene wear debris and the thickness of the synovium and the synovial contents are related. In the event of radiographic loosening of the acetabular component, they are both increased.
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| 4. |
- Lewold, Stefan, et al.
(författare)
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Oxford meniscal bearing knee versus the Marmor knee in unicompartmental arthroplasty for arthrosis. A Swedish multicenter survival study
- 1995
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Ingår i: Journal of Arthroplasty. - 0883-5403. ; 10:6, s. 722-731
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Tidskriftsartikel (refereegranskat)abstract
- In the Swedish Knee Arthroplasty Study, all 699 Oxford meniscal bearing cemented unicompartmental prostheses (Biomet, Bridgend, UK) were identified and analyzed regarding failure pattern and compared with all Marmor prostheses (Smith & Nephew Richards, Orthez, France) and with a time-, age-, and sex-matched subset of Marmor prostheses using survival statistics expressed as cumulative revision rates. After 1 year there was already a higher rate, and after 6 years the rate of the Oxford group was more than twice that of the Marmor group. There were 50 revisions in the Oxford group: dislocating meniscus in 16, loosening of the femoral component in 6, tibial component in 4, both components in 4, contralateral arthrosis in 10, infection in 4, and technical failure with instability, pain, and/or impingement of the meniscal bearing anterior in the femoral condyle in 6. It is still unclear if the design with the sliding menisci will, in the long turn, reduce wear and loosening, thereby compensating for the initially inferior results. It is recommended that until this question is clarified, the Oxford knee should be used on a limited scale for long-term comparative studies only.
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| 5. |
- Robertsson, Otto, et al.
(författare)
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Intracapsular pressure and pain in coxarthrosis
- 1995
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Ingår i: Journal of Arthroplasty. - 0883-5403. ; 10:5, s. 632-635
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Tidskriftsartikel (refereegranskat)abstract
- Intracapsular hip pressure was measured before surgery in 17 patients (18 hips) with coxarthrosis. The results were correlated to pain as registered on a visual analog scale. With the hip in extension, the pressure was 49.5 mmHg (SD, 40.2); in 45 degrees of flexion, it was 21.3 mmHg (SD, 14.6); in extension and inward rotation, it was 105.7 mmHg (SD, 76.0); and in extension and outward rotation, it was 40.8 mmHg (SD, 32.0). A small amount, 0.7 mL (SD, 1.14), of joint fluid was aspirated following pressure registration. Pressure correlated significantly to pain at night, when starting to walk, and on walking. It is suggested that the increase in intracapsular hip pressure is a cause of pain in coxarthrosis, with subsequent limitation of movement and joint contracture.
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| 6. |
- Sanzén, Lennart, et al.
(författare)
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Radiographic wear assessment in a total knee prosthesis. 5- to 9-year follow-up study of 158 knees
- 1996
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Ingår i: Journal of Arthroplasty. - 0883-5403. ; 11:6, s. 738-742
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Tidskriftsartikel (refereegranskat)abstract
- One hundred fifty-eight Porous-Coated Anatomic (Howmedica, Rutherford, NJ) primary total knee prostheses were evaluated clinically and radiographically to measure the remaining thickness of the plastic insert. Anteroposterior radiographs were taken with the beam guided parallel to the tibial plate by a fluoroscope. The knees were forced into varus and valgus, and the heights of the medial and lateral joint spaces, respectively, were measured with a digitizing table. Plastic insert wear could be calculated after correction with a magnification error factor, established by dividing the projected width of the tibial plate by the true size of the used component. After a mean follow-up period of 84 months (range, 58-116 months), wear was significantly higher for patients with osteoarthritis than rheumatoid arthritis and was 1.4 mm versus 0.7 mm medially (P < .0001) and 0.7 mm versus 0.4 mm laterally (P = .01). Wear was not correlated to thickness of the plastic insert or length of follow-up period. Young age or varus alignment contributed slightly to the amount of wear.
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| 7. |
- Toksvig-Larsen, Søren, et al.
(författare)
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The Porous-Coated Anatomic Total Knee Experience. Special Emphasis on Complications and Wear
- 1996
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Ingår i: Journal of Arthroplasty. - 0883-5403. ; 1:11, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- One hundred sixty knees in 141 patients with the Primary Porous-Coated Anatomic prosthesis (Howmedica, Rutherford, NJ) were evaluated after a follow-up period of 5.6 years (range, 1–10 years). One hundred six knees were in the latest follow-up evaluation, including clinical examination and a defined standing radiograph with a follow-up period of 6.3 years (range, 3–10 years). Survivorship analysis regarding the cumulative revision rate (including completion with a patellar component) was 0.88 at the 8-year and 0.84 at the 10-year follow-up examination. The clinical result was satisfying/good, with a mean Hospital for Special Surgery score of 83 (range, 39–97). Five percent had thinning greater than 30% of the tibial component. The wear was calculated to be 1.0 mm (range, 0–9 mm), including three revised tibial components with heavy wear. Excluding the revised cases, the wear was 0.7 mm.
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