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- Persson, Per-Erik, 1949-
(författare)
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Heterotopic Ossification : Clinical and Experimental Studies on Risk Factors, Etiology and Inhibition by Non-steroidal Anti-inflammatory Drugs
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, occurrence of heterotopic ossification (HO) following total hip arthroplasty (THA) was studied. Preventive effects and complications with non-steroidal anti-inflammatory drugs (NSAIDs) were analyzed. Experimental investigations on bone formation were employed to gain insight to the mechanism of NSAIDs action on bone.(I). Fifty-six patients with bilateral THAs were analyzed. We found a strong correlation between HO on the two sides. Incidence and grade of HO were higher in men than in women.(II). Sixty-nine patients with bilateral THAs who had been treated with NSAIDs after one or both THAs were analyzed for HO. Widespread HO occurred in untreated THAs, but in none of the treated THAs.(III). A consecutive series of THAs were analyzed for HO. No widespread HO occurred in patients treated with NSAIDs for 21 days. In contrast, widespread HO occurred in 23% of patients not treated.(IV). A randomized, double-blind, prospective study on 144 patients was performed to determine the efficacy and minimum treatment time with Ibuprofen for prophylaxis of HO after THA. Treatment with Ibuprofen was effective for preventing HO and a treatment time of 8 days was sufficient.(V). A ten-year follow-up examination was performed on the patients from study IV. Thirteen patients had been revised. All but one belonged to groups treated with Ibuprofen. However, the prosthetic survival time was not statistically different for patients treated with NSAIDs compared to the control group. Eighty-four more patients underwent radiographic examination10 years after THA. Nine loose prostheses were found. These were equally distributed between NSAIDs-treated and non-treated THAs. When combining complications (revisions and radiographic loosening) no significant effects could be verified.(VI). Experimental induction of heterotopic new bone with demineralized allogeneic bone matrix (DABM) and with bone autografts, was used in rats to study effects of NSAIDs on new bone formation. Indomethacin inhibited net bone formation in DABMs and in orthotopic fractured bone. In contrast, a net mineral loss occurred in autografts, but neither mineral content nor 45Ca incorporation was affected by Indomethacin treatment. The amount of bone formed per mg implanted DABM was linearly correlated to implant size.
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| 2. |
- Abtahi, Jahan, 1965-, et al.
(författare)
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Impact of a zoledronate coating on early post-surgical implant stability and marginal bone resorption in the maxilla-A split-mouth randomized clinical trial.
- 2019
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Ingår i: Clinical Oral Implants Research. - : John Wiley & Sons. - 0905-7161 .- 1600-0501. ; 30:1, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The objective of this clinical study was to evaluate the effect of a bisphosphonate coating on a titanium implant on the implant stability quotient (ISQ) and the radiographic marginal bone levels at implants during early healing (2-8 weeks).MATERIALS AND METHODS: In a randomized double-blind trial with internal controls, 16 patients received a dental implant coated with zoledronate and one uncoated implant as a control. The coated and uncoated implants which were visually indistinguishable were bone level titanium implants with a moderately rough surface and a microthreaded neck. ISQ values were obtained at insertion and at 2, 4, 6, and 8 weeks. Radiographs were obtained at insertion and at 8 weeks. The primary outcome was the difference in ISQ values between the coated implants and the control implants at 4 and 6 weeks, corrected for insertion values. The secondary outcome was loss of marginal bone level from insertion to 8 weeks.RESULTS: Implant stability quotient values remained largely constant over the 8 weeks, and there was no significant difference between coated and uncoated implants at any time point. There was 0.12 (SD 0.10) mm marginal bone loss at the control implants and 0.04 (SD 0.08) mm at the coated implants. The difference was 0.17 mm; SD 0.14; p < 0.006). On blind qualitative scoring, 13 of the 15 control implants and two of 15 coated implants showed small marginal bone defects (p = 0.003).CONCLUSIONS: There were no statistically significant differences observed in ISQ values between the coated and uncoated implants during the early healing. There was less marginal bone loss at the coated implants.
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| 3. |
- Amirhosseini, Mehdi, et al.
(författare)
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Mechanical instability and titanium particles induce similar transcriptomic changes in a rat model for periprosthetic osteolysis and aseptic loosening
- 2017
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Ingår i: Bone Reports. - : Elsevier. - 2352-1872. ; 7, s. 17-25
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Tidskriftsartikel (refereegranskat)abstract
- Wear debris particles released from prosthetic bearing surfaces and mechanical instability of implants are two main causes of periprosthetic osteolysis. While particle-induced loosening has been studied extensively, mechanisms through which mechanical factors lead to implant loosening have been less investigated. This study compares the transcriptional profiles associated with osteolysis in a rat model for aseptic loosening, induced by either mechanical instability or titanium particles. Rats were exposed to mechanical instability or titanium particles. After 15 min, 3, 48 or 120 h from start of the stimulation, gene expression changes in periprosthetic bone tissue was determined by microarray analysis. Microarray data were analyzed by PANTHER Gene List Analysis tool and Ingenuity Pathway Analysis (IPA). Both types of osteolytic stimulation led to gene regulation in comparison to unstimulated controls after 3, 48 or 120 h. However, when mechanical instability was compared to titanium particles, no gene showed a statistically significant difference (fold change = ± 1.5 and adjusted p-value = 0.05) at any time point. There was a remarkable similarity in numbers and functional classification of regulated genes. Pathway analysis showed several inflammatory pathways activated by both stimuli, including Acute Phase Response signaling, IL-6 signaling and Oncostatin M signaling. Quantitative PCR confirmed the changes in expression of key genes involved in osteolysis observed by global transcriptomics. Inflammatory mediators including interleukin (IL)-6, IL-1ß, chemokine (C-C motif) ligand (CCL)2, prostaglandin-endoperoxide synthase (Ptgs)2 and leukemia inhibitory factor (LIF) showed strong upregulation, as assessed by both microarray and qPCR. By investigating genome-wide expression changes we show that, despite the different nature of mechanical implant instability and titanium particles, osteolysis seems to be induced through similar biological and signaling pathways in this rat model for aseptic loosening. Pathways associated to the innate inflammatory response appear to be a major driver for osteolysis. Our findings implicate early restriction of inflammation to be critical to prevent or mitigate osteolysis and aseptic loosening of orthopedic implants.
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| 4. |
- Aspenberg, Per, 1949-, et al.
(författare)
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Additive effects of PTH and bisphosphonates on the bone healing response to metaphyseal implants in rats
- 2008
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 79:1, s. 111-115
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: When PTH is used to increase the amount of bone in osteoporotic patients, combination with bisphosphonates is known to attenuate the response. This might be explained by the reduced number of remodeling sites after bisphosphonate treatment, which reduces the number of cells able to respond to PTH. However, in a repair situation after trauma, a large number of osteoblasts reside in the wound site. If their activity is no longer coupled to osteoclasts, decreased resorption by bisphosphonates and stimulation of osteoblastic activity by PTH should both (independently) increase bone formation. Thus, we hypothesized that in contrast to the case in osteoporosis treatment, PTH and bisphosphonates have an additive effect in situations involving bone regeneration. MATERIAL AND METHODS: Stainless steel screws, either coated with biphosphonates or uncoated, were inserted in 46 rat tibias. This normally elicits a bone repair response, leading to a gradual increase in the strength of screw fixation. Half of the rats also received daily injections of teriparatide (PTH). Thus, there were 4 groups: control, bisphosphonate, PTH, and bisphosphonate plus PTH. Pull-out force and energy were measured after 2 weeks. RESULTS: The combined treatment had the strongest effect. It doubled the pull-out force and tripled the pull-out energy, compared to untreated controls. Also, bisphosphonate or PTH alone increased the pull-out force and energy, although less. No treatment cross-dependency was observed. INTERPRETATION: Because bisphosphonates mainly influence osteoclasts, and intermittent administration of PTH mainly influences osteoblasts, our findings indicate that to a large extent these cells work without coupling in this model. It appears that bisphosphonates are unlikely to attenuate the response to PTH during the formation of new bone.
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| 5. |
- Aspenberg, Per, 1949-
(författare)
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Apropå! En arrogant organisation
- 2017
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Ingår i: Läkartidningen. - Stockholm, Sweden : Läkartidningen Förlag AB. - 0023-7205 .- 1652-7518. ; 114
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
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| 6. |
- Aspenberg, Per, 1949-, et al.
(författare)
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Artrosskolan : evidensen måste stärkas
- 2018
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Ingår i: Läkartidningen. - : Läkartidningen Förlag AB. - 0023-7205 .- 1652-7518. ; 115
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 7. |
- Aspenberg, Per, 1949-
(författare)
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Avoid cox inhibitors after skeletal surgery!
- 2002
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Ingår i: Acta Orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470. ; 73:5, s. 489-490
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Tidskriftsartikel (refereegranskat)
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