Ilkka Kiviranta

Publications (49)94.2 Total impact

• Article: Osteochondral Repair: Evaluation with Sweep Imaging with Fourier Transform in an Equine Model.

  Jari Rautiainen, Lauri J Lehto, Virpi Tiitu, Outi Kiekara, Hertta Pulkkinen, Anne Brünott, René van Weeren, Harold Brommer, Pieter A J Brama, Jutta Ellermann, Ilkka Kiviranta, Miika T Nieminen, Mikko J Nissi
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  ABSTRACT: Purpose:To evaluate the status of articular cartilage and bone in an equine model of spontaneous repair by using the sweep imaging with Fourier transform (SWIFT) magnetic resonance (MR) imaging technique.Materials and Methods:Experiments were approved by the Utrecht University Animal Ethics Committee. Six-millimeter-diameter chondral (n = 5) and osteochondral (n = 5, 3-4 mm deep into subchondral bone) defects were created in the intercarpal joints of seven 2-year-old horses and examined with SWIFT at 9.4 T after spontaneous healing for 12 months. Conventional T2 maps and gradient-echo images were obtained for comparison, and histologic assessment of cartilage and micro-computed tomography (CT) of bone were performed for reference. Signal-to-noise ratio (SNR) analysis was performed, and a radiologist evaluated the MR images. Structural bone parameters were derived from SWIFT and micro-CT datasets. Significance of differences was investigated with the Wilcoxon signed rank test and Pearson correlation analysis.Results:SWIFT was able to depict the different outcomes of spontaneous healing of focal chondral versus osteochondral defects. SWIFT produced constant signal intensity throughout cartilage, whereas T2 mapping showed elevated T2 values (P = .06) in repair tissue (mean T2 in superficial region of interest in an osteochondral lesion = 50.0 msec ± 10.2) in comparison to adjacent intact cartilage (mean T2 = 32.7 msec ± 4.2). The relative SNR in the subchondral plate with SWIFT (0.91) was more than four times higher than that with conventional fast spin-echo (0.12) and gradient-echo (0.19) MR imaging. The correlation between bone volume-to-tissue volume fractions determined with SWIFT and micro-CT was significant (r = 0.83, P < .01).Conclusion:SWIFT enabled assessment of spontaneous osteochondral repair in an equine model.© RSNA, 2013.
  Radiology 05/2013; · 5.73 Impact Factor
• Article: Sense of Coherence Affects Adherence and Response to Resistance Training in Older People with Hip Fracture History.

  Erja Portegijs, Sanna Read, Inka Pakkala, Mauri Kallinen, Ari Heinonen, Taina Rantanen, Markku Alen, Ilkka Kiviranta, Sanna Sihvonen, Sarianna Sipilä
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  ABSTRACT: Our aim was to study the effects of sense of coherence (SOC) on training adherence and inter-individual changes in muscle strength, mobility and balance after resistance training in older people with hip fracture history. These are secondary analyses of a 12-week randomized controlled trial of progressive resistance training in 60-85-years-old community-dwelling people 0.5-7 years following hip fracture (n=45;ISRCTN34271567). Pre- and post-trial assessments included SOC, knee extension strength, walking speed, timed up-and-go (TUG), and Berg Balance Scale (BBS). Group by SOC interaction effects (repeated measures ANOVA) were statistically significant for TUG (p=0.005) and BBS (p=0.040), but not for knee extension strength or walking speed. Weaker SOC was associated with poorer training adherence (mixed model; p=0.009). Thus, more complicated physical tasks did not improve in those with weaker SOC, independently of training adherence. Older people with weaker SOC may need additional psychosocial support in physical rehabilitation programs to optimize training response.
  Journal of Aging and Physical Activity 03/2013;
• Article: Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial.

  Benjamin Waller, Matti Munukka, Juhani Multanen, Timo Rantalainen, Tapani Pöyhönen, Miika T Nieminen, Ilkka Kiviranta, Hannu Kautiainen, Harri Selänne, Joost Dekker, Sarianna Sipilä, Urho M Kujala, Arja Häkkinen, Ari Heinonen
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  ABSTRACT: Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. A minimum of 80 volunteers who meet the inclusion criteria will be recruited from the local population through newspaper advertisements. Following initial assessment volunteers will be randomised into two groups. The intervention group will participate in a progressive aquatic resistance exercise program of 1-hour duration 3 times a week for four months. The control group will be asked to maintain normal care during this period. Primary outcome measure for this study is the biochemical composition of knee cartilage measured using quantitative magnetic resonance imaging; T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging techniques. In addition, knee cartilage morphology as regional cartilage thickness will be studied. Secondary outcomes include measures of body composition and bone traits using dual energy x-ray absorptiometry and peripheral quantitative computed tomography, pain, function using questionnaires and physical performance tests and quality of life. Measurements will be performed at baseline, after the 4-month intervention period and at one year follow up. This randomised controlled trial will investigate the effect a progressive aquatic resistance exercise program has on the biochemical composition of cartilage in post-menopausal women with mild knee osteoarthritis. This is the first study to investigate what impact aquatic exercise has on human articular cartilage. In addition it will investigate the effect aquatic exercise has on physical function, pain, bone and body composition and quality of life. The results of this study will help optimise the prescription of aquatic exercise to persons with mild knee osteoarthritis. ISRCTN65346593.
  BMC Musculoskeletal Disorders 01/2013; 14:82. · 1.58 Impact Factor
• Article: Cluster analysis of infrared spectra can differentiate intact and repaired articular cartilage.

  Yevgeniya Kobrina, Lassi Rieppo, Simo Saarakkala, Hertta J Pulkkinen, Virpi Tiitu, Piia Valonen, Ilkka Kiviranta, Jukka S Jurvelin, Hanna Isaksson
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  ABSTRACT: OBJECTIVE: Successful repair of articular cartilage (AC) defects would be a major advantage due to the low ability of AC to heal spontaneously. Sensitive methods to determine changes in AC composition and structure are required to monitor the success of repair. This study evaluates the ability of unsupervised cluster analysis applied to Fourier Transform Infrared (FTIR) microspectroscopy to discriminate between healthy and repaired AC. METHODS: Osteochondral lesions (3 mm in depth) were surgically created in patellar grooves of rabbit femurs and were either left to heal spontaneously (n=6) or surgically repaired with autologous chondrocytes in type II collagen gel (n=6). After 6 months, tissues were harvested, FTIR microspectroscopy was conducted and Fuzzy c-means (FCM) cluster analysis applied to spectra of pairs of intact and repaired AC samples from each rabbit. Two spectral regions [amide I and carbohydrate (CHO)] were analyzed and the results from the two types of repair were compared. RESULTS: Two separate regions of repair were detected with FCM. The estimated proteoglycan content (from CHO region) in the repaired AC was significantly lower than that in intact AC. The spontaneously repaired AC was better distinguished from the intact AC than the collagen II gel repaired AC. The most distinct clustering was observed for spontaneously repaired samples using CHO region. CONCLUSIONS: This study revealed that unsupervised cluster analysis applied to FTIR microspectroscopy can detect subtle differences in infrared spectra between normal and repaired AC. The method may help in evaluation and optimization of future AC repair strategies.
  Osteoarthritis and Cartilage 12/2012; · 3.90 Impact Factor
• Article: Evaluation of chondral repair using quantitative MRI.

  Miika T Nieminen, Mikko J Nissi, Lauri Mattila, Ilkka Kiviranta
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  ABSTRACT: Various quantitative magnetic resonance imaging (qMRI) biomarkers, including but not limited to parametric MRI mapping, semiquantitative evaluation, and morphological assessment, have been successfully applied to assess cartilage repair in both animal and human studies. Through the interaction between interstitial water and constituent macromolecules the compositional and structural properties of cartilage can be evaluated. In this review a comprehensive view of a variety of quantitative techniques, particularly those involving parametric mapping, and their relationship to the properties of cartilage repair is presented. Some techniques, such as T2 relaxation time mapping and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), are well established, while the full potential of more recently introduced techniques remain to be demonstrated. A combination of several MRI techniques is necessary for a comprehensive characterization of chondral repair. J. Magn. Reson. Imaging 2012; 36:1287-1299. © 2012 Wiley Periodicals, Inc.
  Journal of Magnetic Resonance Imaging 12/2012; 36(6):1287-99. · 2.70 Impact Factor
• Article: Bone Density, Structure and Strength and Their Determinants in Aging Sprint Athletes.

  Marko T Korhonen, Ari Heinonen, Jaana Siekkinen, Juha Isolehto, Markku Alén, Ilkka Kiviranta, Harri Suominen
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  ABSTRACT: PURPOSE: This study was undertaken to examine bone properties in masters sprinters of different ages and younger reference subjects. In addition, the association of sport-specific ground reaction force, muscle, training and hormone characteristics with the bone parameters were evaluated in the athletes. METHODS: Bone densitometric, structural and strength parameters were assessed by pQCT at the distal and midtibia in 83 male sprinters (40-85 yr) and 19 physically-active referents (31-45 yr). Between-group differences were analyzed by ANCOVA with body mass and height as covariates. RESULTS: Bone values were generally greater in athletes than referents, the greatest differences being in bending strength of the tibia shaft as estimated by maximum moment of inertia (Imax). Among athletes, vBMDtrab of distal tibia was 12% (P<0.05) lower in the oldest (≥70 yr) vs. youngest group, whereas bone mineral content (BMCtot), cross-sectional area (CSAtot) and compressive strength (BSIcomp) did not differ between the groups. At midtibia, no age-group differences were present in BMCtot, CSAtot, cortical wall thickness, cortical density (vBMDco), polar mass distribution, minimum moment of inertia (Imin) or Imax. After controlling for age, body mass and height, most loading-related characteristics, knee extensor muscle thickness and hormone concentrations correlated with the bone parameters. Multivariate regression models explained 12-67% (mean 47.5%) of the variance of the bone parameters. Mechanical power in the eccentric phase of the hopping and body mass were consistently the strongest independent predictors in the models. CONCLUSION: The results suggest that regular sprint training has positive (direction-specific) effects on bone strength and structure in middle- and older-aged athletes. Inter-individual differences in bone traits seem to be due to combined effects of exercise loading, body size and hormonal characteristics.
  Medicine and science in sports and exercise 07/2012; · 3.71 Impact Factor
• Article: Balance Confidence Was Associated With Mobility and Balance Performance in Older People With Fall-Related Hip Fracture: A Cross-Sectional Study.

  Erja Portegijs, Johanna Edgren, Anu Salpakoski, Mauri Kallinen, Taina Rantanen, Markku Alen, Ilkka Kiviranta, Sanna Sihvonen, Sarianna Sipilä
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  ABSTRACT: Portegijs E, Edgren J, Salpakoski A, Kallinen M, Rantanen T, Alen M, Kiviranta I, Sihvonen S, Sipilä S. Balance confidence was associated with mobility and balance performance in older people with fall-related hip fracture: a cross-sectional study. OBJECTIVE: To study the relationship between balance confidence, a concept closely related to fear of falling, mobility and balance performance, and perceived mobility limitation in older people after a fall-related hip fracture. DESIGN: Cross-sectional analyses of pretrial data of 2 randomized controlled trials of physical rehabilitation. SETTING: University research center. PARTICIPANTS: Community-dwelling people aged over 60 years, 6 weeks to 7.5 years after a fall-related hip fracture (N=130). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The main outcome was the self-reported Activities-specific Balance Confidence (ABC) scale score. Assessments also included perceived ability to walk outdoors or climb 1 flight of stairs, and assessments of self-preferred walking speed, modified Timed-Up-and-Go test, and Berg Balance Scale. RESULTS: Higher ABC scale scores were related to better mobility and balance performance (ρ>.47) and perceived mobility function (ρ>.54). In univariate general linear models, all associations also remained significant after adjustment for age, sex, time since fracture, number of chronic diseases, and either level of physical activity or muscle strength of the fractured leg. An ABC scale score <85 points identified those with mobility and balance limitation across measures. CONCLUSIONS: In people who have had a fall-related hip fracture, an independent relationship exists between balance confidence and mobility and balance performance as well as perceived mobility function. Since lack of balance confidence may compromise rehabilitation and recovery, the ABC scale may help to identify older hip fracture patients with mobility and balance limitation.
  Archives of physical medicine and rehabilitation 06/2012; · 2.18 Impact Factor
• Article: Effects of intensive strength-power training on sense of coherence among 60-85-year-old people with hip fracture: a randomized controlled trial.

  Inka Pakkala, Sanna Read, Sarianna Sipilä, Erja Portegijs, Mauri Kallinen, Ari Heinonen, Markku Alen, Ilkka Kiviranta, Taina Rantanen
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  ABSTRACT: Older people with disabilities are at increased risk of psychological health decline. There are no earlier studies on the effects of resistance training on sense of coherence (SOC) among older people with a history of hip fracture. The aim of this study is to test the effects of intensive 12-week strength-power training on SOC among older adults after hip fracture. A clinical sample of 60-85-year-old community-dwelling men and women was studied, 0.5. to 7.0 years after hip fracture. Forty-six had no contraindications for participation and were randomized into training (n=24) and control groups (n=22). The training group participated in a 12-week, individually tailored, strength-power training program, twice a week in a senior gym and supervised by an experienced physiotherapist. SOC was assessed with Antonovsky's short 13-item scale. Data were collected at baseline and after intervention. Intensive 12-week strength-power training had no effect on participants' SOC level. Results indicated no change in SOC after 12-week physical exercise training among participants after hip fracture. Further studies on SOC among older people with disabilities and potential ways of increasing it are needed.
  Aging - Clinical and Experimental Research 06/2012; 24(3):295-9.
• Article: Effects of progressive resistance training on physical disability among older community-dwelling people with history of hip fracture.

  Johanna Edgren, Taina Rantanen, Ari Heinonen, Erja Portegijs, Markku Alén, Ilkka Kiviranta, Mauri Kallinen, Sarianna Sipilä
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  ABSTRACT: Hip fracture is a common trauma in older people, and often leads to decreased muscle strength and increased physical disability. This randomized controlled trial examined whether three months of progressive resistance training (PRT) can reduce physical disability among older people with a history of hip fracture. A population-based sample of 60-85-year-old community- dwelling persons, with hip fractures sustained on average three years earlier, were enrolled in the study. Of 78 people participating in laboratory assessments, those without contraindications for participation in resistance training were randomly assigned to a training group (TG, n=22) or a control group (CG, n=21). TG took part in resistance training for three months twice a week. Training focused on lower limb muscles. Disability was assessed by a validated questionnaire containing six questions on activities of daily living (ADL) and nine on instrumental activities of daily living (IADL). A sum score was calculated separately for both items. High scores indicated more difficulties. Group differences were analysed with the Mann-Whitney and Chi-square tests. The effects of PRT on disability were tested with the McNemar test and by covariance analysis (ANCOVA). TG and CG were comparable with respect to gender, age, chronic diseases, BMI, time since fracture, self-reported health, and level of physical activity at baseline. The ADL sum score in TG was 1.8 (2.0) at baseline and 1.1 (1.3) after follow-up; in CG values were 1.7 (1.8) and 1.5 (1.8) (ANCOVA p=0.034). IADL sum scores in TG were 3.9 (4.6) at baseline and 2.2 (3.8) after follow-up, and in CG 3.4 (3.6) and 2.4 (2.3) (ANCOVA p=0.529). Progressive resistance training reduced self-reported difficulties in ADL, even several years after fracture. More research is still needed on how to prevent physical disability among community-dwelling older people, especially after hip fracture.
  Aging - Clinical and Experimental Research 04/2012; 24(2):171-5.
• Article: Influence of different DXA acquisition modes on monitoring the changes in bone mineral density after hip resurfacing arthroplasty.

  Mikko A Hakulinen, Håkan Borg, Arja Häkkinen, Tapani Parviainen, Ilkka Kiviranta, Jukka S Jurvelin
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  ABSTRACT: Dual-energy X-ray absorptiometry (DXA) is a technique enabling the measurement of bone mineral density (BMD) around prostheses after hip resurfacing arthroplasty (HRA). In this study, we evaluated the consistency of different DXA acquisition modes with 33 patients who had undergone HRA. Patients were scanned with DXA immediately after surgery and at 3-, 6-, and 12-mo time points. All the patients were scanned with dual femur and orthopedic hip acquisition modes and analyzed using 10-region ROI model. With both acquisition modes, a statistically significant decrease (p<0.05, Wilcoxon's test) in BMD at 3mo was revealed in 3 ROIs, located to upper and lateral upper femur. Both acquisition modes detected similarly (p<0.01) preservation of the femoral bone stock within 12mo in all but 1 ROI. The applied acquisition protocols involved the use of different footplates for hip fixation. Because the differences between acquisition modes ranged between +1.6% and -7.1% and the reproducibility of BMD values can vary by as much as 28% due to hip rotation, it is proposed that both dual femur and orthopedic hip acquisition modes can be used to monitor the changes in BMD after HRA. However, the same hip rotation is recommended for all DXA measurements.
  Journal of Clinical Densitometry 11/2011; 15(1):72-7. · 1.29 Impact Factor
• Article: [Implementation of preoperative physiotherapy and recovery after shoulder impingement surgery].

  Mirja Vuorenmaa, Arja Häkkinen, Juha Paloneva, Ilkka Kiviranta, Hannu Kautiainen, Oikari Marjo, Jari Ylinen
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  ABSTRACT: Subacromial impingement syndrome is a common orthopedic condition. Patients operated due to shoulder impingement (n=104) were sent a questionnaire inquiring rehabilitation procedures before and after surgery, pain and shoulder function. Response rate was 68%, mean age of the patients was 53 years. Before surgery, 50% of the patients had received physiotherapy. The symptoms disappeared after surgery in the majority of the patients. However, 13% of the patients had significant shoulder pain (VAS over 30 mm) one year postoperatively and 15% had considerable functional deficit. To avoid unnecessary operations for shoulder impingement proper conservative treatment must be provided before surgery.
  Duodecim; lääketieteellinen aikakauskirja 01/2011; 127(9):935-40.
• Source

  Available from: Mikko A Hakulinen

  Article: Bone mineral density of the proximal femur after hip resurfacing arthroplasty: 1-year follow-up study.

  Arja Häkkinen, Håkan Borg, Mikko Hakulinen, Jukka Jurvelin, Esa Anttila, Tapani Parviainen, Ilkka Kiviranta
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  ABSTRACT: Hip resurfacing arthroplasty (HRA) is considered a bone-preserving procedure and may eliminate proximal femoral stress shielding and osteolysis. However, in addition to implant-related stress-shielding factors, various patient-related factors may also have an effect on bone mineral density (BMD) of the proximal femur in patients with HRA. Thus, we studied the effects of stem-neck angle, demographic variables, and physical functioning on the BMD of the proximal femur in a one-year follow-up. Thirty three patients (9 females and 24 males) with a mean (SD) age of 55 (9) years were included in the study. BMD was measured two days and 3, 6, and 12 months postoperatively and 10 regions of interest (ROI) were used. Stem-neck angle was analyzed from anteroposterior radiographs. Three months postoperatively, BMD decreased in six out of 10 regions of interest (ROI) on the side operated on and in one ROI on the control side (p<0.05) compared to the second postoperative day. At 12 months, BMD had increased in 7 ROIs on the operated side and one ROI on the control side (all p<0.001). Correlation was found between the stem-neck angle and BMD in ROIs 2, 3, 7, and 9 (r=0.36-0.61). In multiple regression analysis, stem-neck angle, age, sex, body mass index, and walking distance did not explain the BMD changes. After an early drop, the BMD of the upper femur was restored and even exceeded the preoperative level at one year follow-up. From a clinical standpoint, the changes in BMD in these HRA patients could not be explained by stem-neck angle or patient related factors.
  BMC Musculoskeletal Disorders 01/2011; 12:100. · 1.58 Impact Factor
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  Available from: gnmhealthcare.com

  Article: Physical inactivity and pain in older men and women with hip fracture history.

  Anu Salpakoski, Erja Portegijs, Mauri Kallinen, Sanna Sihvonen, Ilkka Kiviranta, Markku Alen, Taina Rantanen, Sarianna Sipilä
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  ABSTRACT: Hip fracture patients often suffer from pain for several months after surgery. This may lead to physical inactivity and subsequent mobility limitation and disability. The purpose of this study was to investigate the association between severe musculoskeletal pain and the level of physical activity in older people with a history of hip fracture. Data were collected from 60- to 85-year-old (n = 78) community-dwelling people, 0.7-7.5 years after hip fracture. Physical activity was assessed with the Yale Physical Activity Survey (YPAS). According to the YPAS summary index distribution, the participants were divided into the physically inactive and physically active groups. Musculoskeletal pain in the lower back, hip or knee region was assessed by the Visual Analog Scale. Pain was defined as severe pain if the subject rated the pain 66 mm or over (upper third of the scale) in at least one of the relevant body regions in the lower body. Thirty-three subjects (42%) experienced severe pain in the lower body, of whom 23 (70%) reported severe pain in the operated hip. Twenty-three patients (30%) used pain medication prescribed by a physician. The level of musculoskeletal pain was significantly higher in the physically inactive (62%) than in the physically active (31%) group (p = 0.011). Logistic regression analysis showed that people with severe pain had over three times (OR: 3.5, 95% CI: 1.30-9.39) the risk for physical inactivity compared to those with less or no pain. Multivariate adjustments for balance confidence, time since fracture, number of chronic diseases and type of surgery did not materially change the estimate (OR: 3.0, 95% CI: 1.00-9.30). Pain is an important associated factor of physical inactivity in older people with a hip fracture history. Pain management may be important in restoring and sustaining the level of physical activity after hip fracture. Further prospective and experimental studies are, however, needed to explore the causality between pain and physical activity as well as the role of pain management and physical activity interventions in preventing mobility limitation and disability among older people recovering from hip fracture.
  Gerontology 01/2011; 57(1):19-27. · 2.78 Impact Factor
• Article: Ultrasound evaluation of mechanical injury of bovine knee articular cartilage under arthroscopic control.

  Tuomas Virén, Simo Saarakkala, Virpi Tiitu, Jani Puhakka, Ilkka Kiviranta, Jukka Jurvelin, Juha Töyräs
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  ABSTRACT: A local cartilage injury can trigger development of posttraumatic osteoarthritis (OA). Surgical methods have been developed for repairing cartilage injuries. Objective and sensitive methods are needed for planning an optimal surgery as well as for monitoring the surgical outcome. In this laboratory study, the feasibility of an arthroscopic ultrasound technique for diagnosing cartilage injuries was investigated. In bovine knees (n = 7) articular cartilage in the central patella and femoral sulcus was mechanically degraded with a steel brush modified for use under arthroscopic control. Subsequently, mechanically degraded and intact adjacent tissue was imaged with a high frequency (40 MHz) intravascular ultrasound device operated under arthroscopic guidance. After opening the knee joint, mechanical indentation measurements were also conducted with an arthroscopic device at each predefined anatomical site. Finally, cylindrical osteochondral samples were extracted from the measurement sites and prepared for histological analysis. Quantitative parameters, i.e., reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB), and ultrasound roughness index (URI) were calculated from the ultrasound signals. The reproducibilities (sCV %) of the measurements of ultrasound parameters were variable (3.7% to 26.1%). Reflection and roughness parameters were significantly different between mechanically degraded and adjacent intact tissue (p < 0.05). Surface fibrillation of mechanically degraded tissue could be visualized in ultrasound images. Furthermore, R and IRC correlated significantly with the indentation stiffness. The present results are encouraging; however, further technical development of the arthroscopic ultrasound technique is needed for evaluation of the integrity of human articular cartilage in vivo.
  IEEE transactions on ultrasonics, ferroelectrics, and frequency control 01/2011; 58(1):148-55. · 1.80 Impact Factor
• Article: Quantitative evaluation of spontaneously and surgically repaired rabbit articular cartilage using intra-articular ultrasound method in situ.

  Tuomas Virén, Simo Saarakkala, Jukka S Jurvelin, Hertta J Pulkkinen, Virpi Tiitu, Piia Valonen, Ilkka Kiviranta, Mikko J Lammi, Juha Töyräs
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  ABSTRACT: During the last decade, a major effort has been devoted to developing surgical methods for repairing localized articular cartilage lesions. Despite some promising results no ultimate breakthrough in surgical cartilage repair has been achieved. Improvements in repair techniques would benefit from more sensitive and quantitative methods for long-term follow-up of cartilage healing. In this study, the potential of a new ultrasound technique for detecting the compositional and structural changes in articular cartilage after surgery, using recombinant human type II collagen gel and spontaneous repair was, investigated. Rabbit knee joints containing intact (n = 13) and surgically (n = 8) or spontaneously (n = 5) repaired tissue were imaged in situ at 6 months after the operation using a clinical intravascular high-frequency (40 MHz) ultrasound device. Based on the ultrasound raw data, ultrasound reflection coefficient (R), integrated ultrasound reflection coefficient (IRC), apparent integrated backscattering coefficient (AIB) and ultrasound roughness index (URI) were determined for each sample. URI was significantly higher in both repair groups than in intact cartilage (p < 0.05). The reflection parameters (R and IRC) were significantly lower in surgically repaired cartilage (p < 0.05) than in intact cartilage. Furthermore, AIB was significantly higher in surgically repaired cartilage than in intact tissue (p < 0.05). To conclude, the integrity of the rabbit articular cartilage repair could be quantitatively evaluated with the nondestructive ultrasound approach. In addition, clinically valuable qualitative information on the changes in cartilage integration, structure and composition could be extracted from the ultrasound images. In the present study, the structure and properties of repaired tissue were inferior to native tissue at 6 months after the operation. The applied ultrasound device and probes are FDA approved and, thus, applicable for the quantitative in vivo evaluation of human articular cartilage.
  Ultrasound in medicine & biology 05/2010; 36(5):833-9. · 2.02 Impact Factor
• Source

  Available from: Timo Rantalainen

  Article: Neuromuscular performance and body mass as indices of bone loading in premenopausal and postmenopausal women.

  Timo Rantalainen, Riku Nikander, Ari Heinonen, Juhani Multanen, Arja Häkkinen, Timo Jämsä, Ilkka Kiviranta, Vesa Linnamo, Paavo V Komi, Harri Sievänen
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  ABSTRACT: The strong association between body mass and skeletal robusticity has been attributed to increasing skeletal loading with increasing mass. However, it is unclear whether body mass is merely a coarse substitute for bone loading rather than a true independent predictor of bone strength. As indices of neuromuscular performance, impulse and peak power were determined from vertical ground reaction force during a maximal counter movement jump test in 221 premenopausal and 82 postmenopausal women. Bone compressive (BSI(d) g(2)/cm(4)) and bending (SSImax(mid) mm(3)) strength indices were measured with peripheral quantitative computed tomography (pQCT) at the distal ((d)) and midshaft ((mid)) sites of the tibia. A two-step forced regression model for predicting bone strength indices was constructed. Age, height and body mass were entered first, followed by impulse as an indicator of skeletal loading. The basic model explained 14% (P<0.001) of the variance in BSI(d) in the premenopausal group and 16% (P=0.004) in the postmenopausal group, and 32% (P<0.001) and 25% (P<0.001) of the variance in SSImax(nud) respectively. Entering impulse into the model increased the explanatory power by 9% (P<0.001) and 7% (P<0.001) for BSI(d) and by 8% (P<0.001) and 12% (P<0.001) for SSImax(mid). Furthermore, impulse replaced body mass as an independent significant factor explaining the variance in bone strength. These results indicate that neuromuscular performance should be measured and preferred over body mass in models predicting skeletal robusticity.
  Bone 04/2010; 46(4):964-9. · 4.02 Impact Factor
• Article: Quantitative analysis of collagen network structure and fibril dimensions in cartilage repair with autologous chondrocyte transplantation.

  Teemu K Långsjö, Anna I Vasara, Mika M Hyttinen, Mikko J Lammi, Antti Kaukinen, Heikki J Helminen, Ilkka Kiviranta
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  ABSTRACT: The aim of this study was to undertake a stereological analysis to quantify the dimensions of the collagen network in the repair tissue of porcine joints after they had been subjected to autologous chondrocyte transplantation (ACT). ACT was used to repair cartilage lesions in knee joints of pigs. Electron-microscopic stereology, immunostaining for type II collagen, and quantitative polarized-light microscopy were utilized to study the collagen fibrils in the repair tissue 3 and 12 months after the operation. The collagen volume density (V(V)) was lower in the repair tissue than in normal cartilage at 3 months (20.4 vs. 23.7%) after the operation. The collagen surface density (S(V), 1.5·10(-2) vs. 3.1·10(-2) nm(2)/nm(3)) and V(V) increased with time in the repair tissue (20.4 vs. 44.7%). Quantitative polarized-light microscopy detected a higher degree of collagen parallelism in the repair tissue at 3 months after the operation (55.7 vs. 49.7%). In contrast, 1 year after the operation, fibril parallelism was lower in the repair tissue than in the control cartilage (47.5 vs. 69.8%). Following ACT, V(V) and S(V) increased in the repair tissue with time, reflecting maturation of the tissue. One year after the operation, there was a lower level of fibril organization in the repair tissue than in the control cartilage. Thus, the newly synthesized collagen fibrils in the repair tissue appeared to form a denser network than in the control cartilage, but the fibrils remained more randomly oriented.
  Cells Tissues Organs 01/2010; 192(6):351-60. · 2.20 Impact Factor
• Article: Muscle strength and range of movement deficits 1 year after hip resurfacing surgery using posterior approach.

  Arja Häkkinen, Håkan Borg, Hannu Kautiainen, Esa Anttila, Keijo Häkkinen, Jari Ylinen, Ilkka Kiviranta
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  ABSTRACT: The aim was to evaluate the effect of the posterior surgical approach on hip muscle strength and range of movement (ROM). Maximal isometric external and internal rotator strength of the hip muscles and bilateral leg extension strength were measured by dynamometers. Active (AROM) and passive (PROM) range of motion of the hip were measured by goniometers in 30 patients before and 3, 6 and 12 months after hip resurfacing. Postoperatively the patients were advised to return to their usual physical activities. Prior to the surgery internal rotation strength was on the same level on both sides, whereas external rotation strength of the operated hip was 26% (p < 0.001) lower compared with the unoperated side. External rotation strength remained at the lowered level, but internal rotation strength of the operated hip increased over the level of the contralateral side (both p < 0.001) at 12-month follow-up leading to the imbalance in external/internal rotation strength ratio (p < 0.001). Preoperatively, all active and passive ROMs of the operated side were statistically lower than on the unoperated side (p < 0.001). ROMs of the operated hip improved significantly with the exceptions that active external rotation decreased after the operation (p < 0.001). The patients reported remarkable decrease in pain postoperatively. However, the surgical procedure, particularly the division of the external hip rotator muscles led to specific external rotation strength and ROM deficits. Because typical spontaneous physical activity could not restore hip function, there is a need for specific postoperative rehabilitative programs.
  Disability and Rehabilitation 10/2009; 32(6):483-91. · 1.50 Impact Factor
• Article: Postural balance and self-reported balance confidence in older adults with a hip fracture history.

  Sanna Sihvonen, Jenni Kulmala, Mauri Kallinen, Markku Alén, Ilkka Kiviranta, Sarianna Sipila
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  ABSTRACT: Balance dysfunction and loss of balance confidence have been associated with functional limitations and loss of independency in daily tasks. This study examined various aspects of postural balance and balance confidence between older adults with a hip fracture history and their non-fractured counterparts. A comprehensive assessment of balance capacity in older adults with a hip fracture history may help to identify aspects of postural balance that play an important role in the mobility recovery and the avoidance of further falls. The present study comprised 79 community-dwelling older adults with a hip fracture history and 31 non-fractured subjects of the same age, who participated in balance tests including both force platform measures and functional balance testing (Berg Balance Scale, BBS). In addition, balance confidence was assessed with the Activities-Specific Balance Confidence (ABC) scale. Persons with a hip fracture history had a markedly poorer balance control and were significantly less confident maintaining their balance during daily activities compared to the controls. Sixty percent of the subjects in the hip fracture group versus 87% of the non-fracture group (chi(2) test, p = 0.003) were able to perform the semi-tandem standing with their eyes closed. Significantly lower scores in the BBS (hip fracture group 46.3 vs. non-fracture group 52.9) and ABC (hip fracture group 59.4 vs. non-fracture group 77.5%) tests were found among the hip fracture subjects compared to the controls. In addition, the performance time in the lateral weight-shifting task (hip fracture group 13.4 vs. non-fracture group 8.4 s) was significantly slower compared to the controls. Balance impairments along with the loss of balance confidence are persistent problems among community-dwelling older adults with a history of hip fracture and may contribute to mobility limitations and the risk of falling. These areas of function and behaviour in older adults with a hip fracture history should be taken into consideration when planning effective, well-targeted rehabilitation programs.
  Gerontology 09/2009; 55(6):630-6. · 2.78 Impact Factor
• Article: Lower-limb pain, disease, and injury burden as determinants of muscle strength deficit after hip fracture.

  Erja Portegijs, Taina Rantanen, Mauri Kallinen, Ari Heinonen, Markku Alen, Ilkka Kiviranta, Sarianna Sipilä
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  ABSTRACT: Hip fracture may result in an asymmetrical lower-limb strength deficit. The deficit may be related to the trauma, surgical treatment, pain, or disuse of the fractured limb. However, disease and injury burden or musculoskeletal pain in the other limb may reduce muscle strength on that side, reducing the asymmetrical deficit. The aim of our study was to explore the asymmetrical strength deficit and to determine the potential underlying factors in patients from six months to seven years after a hip fracture. The asymmetrical deficit was calculated ([fractured limb/sum of both lower limbs] x 100%) for isometric knee extension torque, rate of force development during isometric testing, and leg extension power. The asymmetrical measures for lower-limb muscle mass (fractured limb--nonfractured limb), and that of lower-limb pain and disease and injury burden (nonfractured limb--fractured limb), were calculated. Half of the participants had no consistent asymmetrical deficit on the fractured side. Regression analyses showed that asymmetrical measures of lower-limb pain, muscle mass, and disease and injury burden predicted asymmetrical deficit in knee extension torque (R(2) = 0.43) and in the rate of force development (R(2) = 0.36). More intense pain and disease and injury burden affecting the nonfractured limb and smaller muscle mass relative to the fractured limb were associated with a smaller asymmetrical deficit. Following a hip fracture, the prevention of decreases in muscle strength and power as well as a large asymmetrical deficit by the use of targeted pain management and rehabilitation may help to reduce the risk of subsequent mobility limitations and falls.
  The Journal of Bone and Joint Surgery 08/2009; 91(7):1720-8. · 3.27 Impact Factor