umu.sePublications
Change search
Refine search result
1 - 9 of 9
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Al-Amiry, Bariq Sh.
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Gaber, John F.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Kadum, Bakir K.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Brismar, Torkel B.
    Sayed-Noor, Arkan S.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    The Influence of Radiological Severity and Symptom Duration of Osteoarthritis on Postoperative Outcome After Total Hip Arthroplasty: A Prospective Cohort Study2018In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 33, no 2, p. 436-440Article in journal (Refereed)
    Abstract [en]

    Background: We aimed to investigate the influence of preoperative radiological severity and symptom duration of hip osteoarthritis (OA) on the postoperative functional outcome, quality of life, as well as abductor muscle strength after total hip arthroplasty (THA). Methods: In this prospective cohort study, we studied 250 patients. Preoperatively, we evaluated the function with the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and quality of life with euroqol-5D (EQ-5D). At 1 year after THA, the same scores and also hip abductor muscle strength were measured in 222 patients. We divided the cohort twice, first according to the radiological OA severity [Kellgren-Lawrence classification (KL)] and then according to the OA symptom duration. We investigated whether the preoperative KL class and symptom duration influenced the 1-year WOMAC (primary outcome measure) or EQ-5D and abductor muscle strength (secondary outcome measures). Results: The crude results showed that KL class and symptom duration had no influence (P = .90 and P = .20, respectively) on the 1-yearWOMAC. Younger age, male gender, and lower body mass index were associated with a better function. Regarding 1-year EQ-5D, the crude results showed that body mass index and KL class had no influence (P = .83 and P = .39, respectively). The adjusted results showed that only age and gender influenced the postoperative EQ-5D. No influence of the tested factors was found on the 1-year abductor muscle strength. Conclusion: Preoperative radiological OA severity and symptom duration had no influence on the outcome of THA and should probably not affect the decision about timing the operative intervention. 

  • 2.
    Bjerke, Joakim
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Department of Physiotherapy, School of Health Education & Social Work, Sør-Trøndelag University College, Trondheim, Norway.
    Öhberg, Fredrik
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nilsson, Kjell G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Foss, Olav A
    Orthopaedic Research Centre, Trondheim University Hospital, Trondheim, Norway.
    Stensdotter, Ann-Katrin
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Department of Physiotherapy, School of Health Education & Social Work, Sør-Trøndelag University College, Trondheim, Norway.
    Peak knee flexion angles during stair descent in TKA patients2014In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 29, no 4, p. 707-711Article in journal (Refereed)
    Abstract [en]

    Reduced peak knee flexion during stair descent (PKSD) is demonstrated in subjects with total knee arthroplasty (TKA), but the underlying factors are not well studied. 3D gait patterns during stair descent, peak passive knee flexion (PPKF), quadriceps strength, pain, proprioception, demographics, and anthropometrics were assessed in 23 unilateral TKA-subjects ~ 19 months post-operatively, and in 23 controls. PKSD, PPKF and quadriceps strength were reduced in the TKA-side, but also in the contralateral side. A multiple regression analysis identified PPKF as the only predictor (57%) to explain the relationship with PKSD. PPKF was, however sufficient for normal PKSD. Deficits in quadriceps strength in TKA-group suggest that strength is also contributing to smaller PKSD. Increased hip adduction at PKSD may indicate both compensatory strategy and reduced hip strength.

  • 3.
    Bjerke, Joakim
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Department of Physiotherapy, School of Health Education & Social Work, Sør-Trøndelag University College, Trondheim, Norway.
    Öhberg, Fredrik
    Department of Biomedical Engineering & Informatics, Umeå University Hospital, Umeå, Sweden.
    Nilsson, Kjell G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Stensdotter, Ann-Katrin
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Department of Physiotherapy, School of Health Education & Social Work, Sør-Trøndelag University College, Trondheim, Norway.
    Compensatory strategies for muscle weakness during stair ascent in subjects with total knee arthroplasty2014In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 29, no 7, p. 1499-1502Article in journal (Refereed)
    Abstract [en]

    Subjects with total knee arthroplasty (TKA) exhibit decreased quadriceps and hamstring strength. This may bring about greater relative effort or compensatory strategies to reduce knee joint moments in daily activities. To study gait and map out the resource capacity, knee muscle strength was assessed by maximal voluntary concentric contractions, and whole body kinematics and root mean square (RMS) electromyography (EMG) of vastus lateralis and semitendinosus were recorded during stair ascent in 23 unilateral TKA-subjects ~19months post-operation, and in 23 healthy controls. Muscle strength and gait velocity were lower in the TKA group, but no significant group differences were found in RMS EMG or forward trunk lean. The results suggest that reduced walking velocity sufficiently compensated for reduced knee muscle strength.

  • 4. Callary, Stuart A
    et al.
    Campbell, David G
    Mercer, Graham E
    Nilsson, Kjell G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Field, John R
    The 6-Year Migration Characteristics of a Hydroxyapatite-Coated Femoral Stem A Radiostereometric Analysis Study2012In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 27, no 7, p. 1344-1348Article in journal (Refereed)
    Abstract [en]

    A prospective cohort of 30 patients undergoing primary total hip arthroplasty for treatment of osteoarthritis was enrolled in a study to characterize the migration behavior of a clinically successful cementless stem. At 6 years, the mean subsidence of the stem was 0.63 mm (range, -0.33 to 3.68 mm); the mean rotation into retroversion was 1.41° (range, -1.33° to 7.48°). No stems had additional subsidence of more than 0.25 mm between 6 months and 6 years. The resultant mean subsidence between 2 and 6 years was 0.03 mm, which is below the limit measurable by radiostereometric analysis. The data demonstrate that subsidence of this cementless stem occurs within the first 6 months, after which there is persistent stabilization.

  • 5.
    Mahmood, Sarwar
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences. Sundsvall and Norrland University Hospitals.
    Mukka, Sebastian S
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences. Sundsvall and Norrland University Hospitals.
    Crnalic, Sead
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences. Sundsvall and Norrland University Hospitals.
    Sayed-Noor, Arkan S
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences. Sundsvall and Norrland University Hospitals.
    The Influence of Leg Length Discrepancy after Total Hip Arthroplasty on Function and Quality of Life: a Prospective Cohort Study2015In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 30, no 9, p. 1638-1642Article in journal (Refereed)
    Abstract [en]

    We investigated whether patients with lengthening (> 9 mm), restoration (between 9 mm lengthening and 5 mm shortening) or shortening (> 5 mm) of the operated leg after total hip arthroplasty (THA) had different function (WOMAC score), quality of life (EQ-5D), residual hip pain, use of shoe lift and walking aid and leg length discrepancy (LLD) awareness, 12-15 months postoperatively. All patients had a significant postoperative improvement in WOMAC and EQ-5D regardless the LLD. However, the lengthening group showed less improvement in WOMAC, more use of shoe lift, residual hip pain and LLD awareness compared with the other two groups. No differences in EQ-5D were found. In spite of the improvement in function and quality of life, lengthening had adverse effects and should therefore be avoided.

  • 6.
    Mukka, Sebastian S.
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Andersson, Göran N.
    Hultenby, Kjell R.
    Sköldenberg, Olof G.
    Nordahl, Joakim P.
    Eisler, Thomas M.
    Osteoclasts in periprosthetic osteolysis: the charnley arthroplasty revisited2017In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 32, no 10, p. 3219-3227Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Periprosthetic osteolysis by polyethylene wear debris-triggered osteoclasts is viewed as the main pathophysiological pathway in aseptic loosening in total hip arthroplasty. The present aim was to study osteoclast occurrence in osteolytic lesions in early and late revisions of the Charnley low-friction torque arthroplasty (CLFA).

    METHODS: Biopsies of the soft interface membrane and the adjacent bone were taken from osteolytic lesions during revision of 16 loose CLFA, early (2-6 years) or late (>10 years) after primary surgery. By light microscopy (LM), cell-dense regions with signs of osteoclast-mediated bone resorption were selected for transmission electron microscopy. Three additional patients were studied in LM for osteoclast markers (tartrate-resistant acid phosphatase and Cathepsin K).

    RESULTS: LM disclosed a low-grade chronic inflammation and birefringent particles in most sections. Multiple conglomerates of tartrate-resistant acid phosphatase positive and Cathepsin K positive mononuclear and multinucleated cells were found deep in the fibrous interface membrane. Transmission electron microscopy showed traces of polyethylene-like particles in 67%-100% of the cells. Osteoclast-like cells exhibiting resorptive activity were few (mean, 0.7%; standard deviation, 0.2%), and multinucleated cells, possibly osteoclast precursor cells, located immediately on the bone were also scarce (mean, 2.7%; standard deviation, 5.3%). Multinucleated (odds ratio, 3.0; 95% confidence interval, 1.7-5.5) and macrophage-like cells (odds ratio, 3.6; 95% confidence interval, 2.2-5.6) were typically located deeper in the inflammatory interface membrane with a pathologic appearance with distension and abundance of phagocytic vacuoles. There were no systematic differences in cell populations between early or late revisions.

    CONCLUSION: Despite probable ongoing osteoclastogenesis in the osteolytic lesions, there were few sites of osteoclast-mediated bone resorption. These findings attach a contributing biological explanation to the longevity of the CLFA.

  • 7.
    Otten, Volker T C
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Crnalic, Sead
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Röhrl, Stephan M
    Nivbrant, Bo
    Nilsson, Kjell G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Stability of Uncemented Cups - Long-Term Effect of Screws, Pegs and HA Coating: A 14-Year RSA Follow-Up of Total Hip Arthroplasty2016In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 31, no 1, p. 156-161Article in journal (Refereed)
    Abstract [en]

    Screws, pegs and hydroxyapatite-coating are used to enhance the primary stability of uncemented cups. We present a 14-year follow-up of 48 hips randomized to four groups: press-fit only, press-fit plus screws, press-fit plus pegs and hydroxyapatite-coated cups. Radiostereometric migration measurements showed equally good stability regardless cup augmentation. The mean wear rate was high, 0.21mm/year, with no differences between the groups. Seven hips had radiographical osteolysis but only in hips with augmented cups. Cups without screw-holes compared with cups with screw-holes resulted in better clinical outcome at the 14-year follow-up. Thus, augmentation of uncemented cups with screws, pegs, or hydroxyapatite did not appear to improve the long-term stability compared with press-fit only.

  • 8.
    Röhrl, Stephan M
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Nivbrant, Bosse
    Ström, Håkan
    Nilsson, Kjell G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Effect of augmented cup fixation on stability, wear and osteolysis: a 5-year follow-up of total hip arthroplasty with RSA2004In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 19, no 8, p. 962-971Article in journal (Refereed)
    Abstract [en]

    To evaluate different modes of cementless fixation of hemispherical cups, we operated on 87 hips in 81 patients using 4 different means of cup fixation. The hips were randomly assigned to fixation with press-fit technique only (PF), or with augmentation with screws (S), pegs (P), or hydroxyapatite (HA) coating. The patients were evaluated with radiostereometric analysis (RSA) for cup migration and wear, conventional radiography for osteolysis, and Harris Hip Score for clinical outcome over 5 years. The fixation of the cups did not differ between the groups, but HA showed a tendency to decrease proximal migration. HA-coated cups displayed the best interface with hardly any signs of radiolucent lines, indicating a superior sealing effect of the HA coating. Cups with screws or pegs had more radiolucent lines and osteolytic lesions than the other groups. Radiolucent lines were correlated to higher proximal migration, young age, and female gender (r2=.2). The wear rate of the ethylene oxide-sterilized polyethylene liner was high (0.2 mm/y) but did not differ between the groups. Two cups with a perioperative fracture of the acetabular rim showed large initial migration but stabilized thereafter.

  • 9.
    Röhrl, Stephan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Nivbrant, Bo
    Ming Guo, Li
    Hewitt, Ben
    In vivo wear and migration of highly cross-linked polyethylene cups a radiostereometry analysis study2005In: The Journal of Arthroplasty, ISSN 0883-5403, E-ISSN 1532-8406, Vol. 20, no 4, p. 409-413Article in journal (Refereed)
    Abstract [en]

    In 50 cemented hip arthroplasties, wear and migration of the polyethylene (PE) cups were measured with radiostereometric analysis for a period of 2 years. Twenty had a normal gamma-in-air-sterilized PE, another 20 had a PE sterilized with 30000 Gy followed by heat stabilization (Duration; Stryker Orthopaedics, Mahwah, NJ), and 10 had highly cross-linked PE cups irradiated with 100000 Gy (Crossfire; Stryker Orthopaedics). In the initial 2 months, head penetration (creep) was 63 microm on average for the 3 groups. From 2 to 24 months, the mean proximal head penetration (wear) was 156 microm for standard PE, 138 microm for stabilized PE (P = .45), and 23 microm for highly cross-linked PE (P < .001; analysis of variance). The low in vivo wear rate for highly cross-linked cups was not at the expense of higher migration or less favorable clinical outcome and looks promising.

1 - 9 of 9
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf