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Dive into the research topics where Jaakko Niinimäki is active.

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Featured researches published by Jaakko Niinimäki.


Spine | 2007

Modic changes in endplates of lumbar vertebral bodies: prevalence and association with low back and sciatic pain among middle-aged male workers.

Mari Kuisma; Jaro Karppinen; Jaakko Niinimäki; Risto Ojala; Marianne Haapea; Markku Heliövaara; Raija Korpelainen; Simo Taimela; Antero Natri; Osmo Tervonen

Study Design. Cross-sectional comparison of self-reported low back pain (LBP) symptoms and Modic findings on magnetic resonance imaging (MRI). Objectives. To investigate associations of frequency and intensity of LBP and sciatic pain with Modic changes in a sample of middle-aged male workers with or without whole-body vibration exposure. Summary of Background Data. Vertebral endplate changes are bone marrow lesions visible on MRI and are assumed to be associated with degenerative intervertebral disc disease. Associations of these so-called Modic changes with clinical symptoms are controversial. Furthermore, most of these studies have been performed in selected series of patients. Methods. A total of 228 middle-aged male workers (159 train engineers and 69 sedentary controls) from northern Finland underwent sagittal T1 and T2-weighted MRI. Both endplates of 1140 lumbar interspaces were graded for type and extent of Modic changes. Logistic regression was used to analyze associations of pain variables with Modic changes. Results. Train engineers had on the average higher sciatic pain scores than the sedentary controls, but the prevalence of Modic changes was similar in both occupational groups. Altogether, 178 Modic changes in 128 subjects were recorded: 30% were type I, 66% type II, and 4% both types I and II. Eighty percent of changes occurred at L4–L5 or L5–S1. Modic changes at L5–S1 showed significant association with pain symptoms with increased frequency of LBP (odds ratio [OR] 2.28; 95% confidence interval [CI] 1.44–3.15) and sciatica episodes (OR 1.44; 95% CI 1.01–1.89), and with higher LBP visual analog scores during the past week (OR 1.36; 95% CI 1.06–1.70). Type I lesions and extensive lesions in particular were closely associated with pain. Conclusions. Modic changes at L5–S1 and Modic type I lesions are more likely to be associated with pain symptoms than other types of Modic changes or changes located at other lumbar levels.


Spine | 2006

The Treatment of Disc Herniation-induced Sciatica With Infliximab: One-year Follow-up Results of First Ii, a Randomized Controlled Trial

Timo Korhonen; Jaro Karppinen; Leena Paimela; Antti Malmivaara; Karl-August Lindgren; Chris Bowman; Anthony Hammond; Bruce Kirkham; Simo Järvinen; Jaakko Niinimäki; Nic Veeger; Marianne Haapea; Markus Torkki; Osmo Tervonen; Seppo Seitsalo; Heikki Hurri

Study Design. A randomized controlled trial. Objectives. To evaluate the long-term efficacy of infliximab, a monoclonal antibody against tumor necrosis factor alpha (TNF-α), in patients with acute/subacute sciatica secondary to herniated disc. Summary of Background Data. The results of experimental studies and our open-label trial support the use of infliximab in sciatica. Here we report the 1-year results of a randomized controlled trial (FIRST II, Finnish Infliximab Related STudy) evaluating the efficacy and safety of a single infusion of infliximab for sciatic pain. Methods. Inclusion criteria were unilateral sciatic pain with a disc herniation concordant with the symptoms and signs of radicular pain. Patients had to be candidates for discectomy. Criteria for discectomy included (in addition to a symptomatic disc herniation on MRI) neural entrapment (straight leg raising [SLR] ≤60°) with either a short-term (2–4 weeks) severe or long-term (4–12 weeks) moderate leg pain. Forty patients were allocated to a single intravenous infusion of either infliximab 5 mg/kg or placebo. Differences in the clinical examination parameters (straight leg raise [SLR], muscle strength, sensory defects, tendon reflexes), patient-reported symptoms (leg and back pain using a visual analog scale [VAS], Oswestry disability, quality-of-life [RAND-36]), sick leaves, number of discectomies, and adverse effects between the two treatment groups over the 1-year follow-up were compared using Mann-Whitney U test or Students t test, repeated-measures analysis, or Cox proportional hazards model. Logistic regression was used to assess the predictors of good response. Results. Sixty-seven percent of patients in the infliximab group reported no pain at 52 weeks compared with 63% in the control group (P = 0.72). Similar efficacy was observed between treatment groups for other outcomes. Eight patients in each group required surgery. Three nonserious adverse reactions were encountered in the infliximab group. The response (irrespective of the treatment) was significantly better with shorter symptom duration and less SLR restriction at baseline. Patients in the infliximab group appeared to especially benefit in cases of a L4–L5 (or L3–L4) herniation and if a Modic change was colocalized at the symptomatic level. Conclusions. Although the long-term results of this randomized trial do not support the use of infliximab compared with placebo for lumbar radicular pain in patients with disc herniation-induced sciatica, further study in a subgroup of patients with L4–L5 or L3–L4 herniations, especially in the presence of Modic changes, appears to be warranted.


Spine | 2006

A three-year follow-up of lumbar spine endplate (modic) changes

Mari Kuisma; Jaro Karppinen; Jaakko Niinimäki; Mauno Kurunlahti; Marianne Haapea; Heikki Vanharanta; Osmo Tervonen

Study Design. A longitudinal follow-up of Modic changes on magnetic resonance imaging (MRI). Objectives. To assess the prevalence and natural course Modic changes over a 3-year follow-up period. Summary of Background Data. Modic changes are bone marrow and endplate lesions visible on MRI. To the authors’ knowledge, no follow-up studies on their natural course have been published. Methods. The study population consisted of 60 unoperated sciatica patients 23 to 76 years of age. Baseline and 3-year lumbar MR images from L1–L2 through L5–S1 were analyzed independently by 2 radiologists and a consensus reading was performed. Results. At baseline, the prevalence of Modic changes was 23%. Seven discs had mixed Type I/II, and 63 Type II change. Changes typically occurred at L4–L5 and L5–S1, and associated positively with age (P = 0.009). Ten of 70 discs (14%) with Modic changes at baseline displayed another type at 3 years. Furthermore, the nonconverted changes increased significantly in size. The incidence of new Modic changes during the follow-up was 6% (13 of 230). Conclusions. Modic changes are common MRI findings in patients with degenerative lumbar disc disease. We found evidence that Modic Type II changes may be less stable than previously assumed.


Spine | 2009

Prevalence of degenerative imaging findings in lumbar magnetic resonance imaging among young adults.

Jani Takatalo; Jaro Karppinen; Jaakko Niinimäki; Simo Taimela; Simo Näyhä; Marjo-Riitta Järvelin; Eero Kyllönen; Osmo Tervonen

Study Design. A cross-sectional imaging study of young adults. Objective. To investigate the prevalence of disc degeneration (DD) and displacement, anular tears, and Modic changes in lumbar magnetic resonance imaging (MRI) among young adults. Summary of Background Data. Although low back pain in young adulthood is common, the prevalence of spinal MRI findings at this age remains virtually unknown. Methods. The study population was a subcohort of the Northern Finland Birth Cohort 1986. Subjects living within 100 km of Oulu (n = 874) were invited to participate in lumbar MRI at 20 to 22 years of age (mean: 21.2 years). Degree of DD, type of Modic changes, and presence of disc bulges, herniations, high intensity zone (HIZ) lesions, and radial tears at all lumbar levels were assessed. Results. Three hundred twenty-five women and 233 men (n = 558) attended the MR imaging. DD was significantly more frequent in men (54% vs. 42%, P = 0.005), as was multiple DD (21% vs. 14%, P = 0.036). The prevalences of disc bulges and radial tears were 25% and 9.1%, respectively, without gender differences. HIZ lesions were more common among women than men (8.6% vs. 4.3%, P = 0.046), whereas herniations were significantly more common among men (5.6% vs. 2.5%, P = 0.047). Only 2 disc extrusions were observed, one in each gender. All degenerative disc findings were more common at the L5–S1 level except HIZ lesions, which were most likely at L4–L5. The prevalence of the Modic changes was 1.4%, without gender difference, type I being more common than type II. Typically, Modic changes were located adjacent to a DD Grade 4 disc and at the 2 lowest levels. Conclusion. Almost half of young Finnish adult aged 21 years had at least one degenerated disc, and a quarter had a bulging disc. Modic changes and disc herniations were, however, relatively rare.


Spine | 2004

Efficacy of infliximab for disc herniation-induced sciatica: one-year follow-up.

Timo Korhonen; Jaro Karppinen; Antti Malmivaara; Reijo A. Autio; Jaakko Niinimäki; Leena Paimela; Eero Kyllönen; Karl-August Lindgren; Osmo Tervonen; Seppo Seitsalo; Heikki Hurri

Study Design. An open-label trial. Objectives. To test the long-term efficacy of infliximab, a monoclonal antibody against tumor necrosis factor-alpha (TNF-α), in disc herniation-induced sciatica. Summary of Background Data. Our recent trial indicated that a single infusion of 3 mg/weight-kg of infliximab produced a rapid curative effect in disc herniation-induced sciatica. Here, we describe the 1-year effect of a 3 mg/kg of infliximab in these 10 patients and our experience with a lower dose of 1 mg/kg of infliximab for the same indication in 2 additional patients. Methods. Patients with severe sciatica were treated with a single infusion of infliximab, 3 mg/weight-kg in 10 patients and 1 mg/kg in 2 patients, intravenously over 2 hours. The outcomes (leg and back pain on a 100-mm visual scale, Oswestry disability, clinical signs) were assessed at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year after the infusion. The outcomes with 3 mg/kg of infliximab were compared to 62 patients who received periradicular saline for sciatica in a previous trial. The resorption rate of disc herniations from baseline to 1 year was compared between infliximab and control groups. Results. The response to 1 mg/kg of infliximab for leg pain was good only in 1 of the 2 patients treated, whereas the response to 3 mg/kg of infliximab for leg pain was sustained in most patients over the 1-year follow-up. The 1-year response significantly favored 3 mg/kg of infliximab over periradicular saline in leg pain (P = 0.005) and disability (P = 0.003). Neurologic abnormalities normalized more comprehensively in the infliximab group (P = 0.001). Reduction in disc herniation volume did not differ between the infliximab-treated patients and controls. Conclusions. The results showed that the beneficial effect of a single infusion of 3 mg/kg of infliximab for herniation-induced sciatica is sustained in most patients over a 1-year follow-up period. Furthermore, infliximab does not seem to interfere with the spontaneous resorption of disc herniations.


Spine | 2005

The treatment of disc herniation-induced sciatica with infliximab - Results of a randomized, controlled, 3-month follow-up study

Timo Korhonen; Jaro Karppinen; Leena Paimela; Antti Malmivaara; Karl-August Lindgren; Simo Järvinen; Jaakko Niinimäki; Nic Veeger; Seppo Seitsalo; Heikki Hurri

Study Design. A randomized controlled trial. Objectives. To evaluate the efficacy of infliximab, a monoclonal antibody against tumor necrosis factor (TNF)-&agr; in a randomized controlled setting. Summary of Background Data. Recently, we obtained encouraging results in an open-label study of infliximab in patients with disc herniation-induced sciatica. Furthermore, the results of experimental studies support the use of infliximab in sciatica. Therefore, we initiated a randomized, controlled trial (FIRST II, Finnish Infliximab Related STudy) to confirm the efficacy of a single infusion of infliximab for sciatic pain. Methods. Inclusion criteria were unilateral moderate to severe sciatic pain with an MRI-confirmed disc herniation concordant with the symptoms and signs of radicular pain. Patients had to be candidates for discectomy, as evaluated by an independent orthopedic surgeon. Forty patients were allocated to a single intravenous infusion of either infliximab 5 mg/kg or placebo. Assessments at baseline and various time points included clinical examination with measurement of straight leg raising restriction; questionnaires related to subjective symptoms (leg and back pain by 100-mm visual analog scale, Oswestry disability); sick leaves; number of discectomies; and adverse effects possibly related to treatment. The primary endpoint was a reduction in leg pain from baseline to 12 weeks, which was analyzed using a Mann-Whitney U test and repeated-measures analysis. Results. A significant reduction in leg pain was observed in both groups, with no significant difference between treatment regimens. Similar efficacy was observed between treatment groups for secondary endpoints. Seven patients in each group required surgery. No adverse effects related to treatment were encountered. Conclusions. The results of this randomized trial do not support the use of infliximab for lumbar radicular pain in patients with disc herniation-induced sciatica.


Spine | 2011

Does Lumbar Disc Degeneration on Magnetic Resonance Imaging Associate With Low Back Symptom Severity in Young Finnish Adults

Jani Takatalo; Jaro Karppinen; Jaakko Niinimäki; Simo Taimela; Simo Näyhä; Pertti Mutanen; Roberto Blanco Sequeiros; Eero Kyllönen; Osmo Tervonen

Study Design. A cross-sectional magnetic resonance imaging study with questionnaires on low back pain (LBP) and functional limitations. Objective. To investigate the association between lumbar intervertebral disc degeneration (DD) and low back symptom severity among young Finnish adults. Summary of Background Data. Both LBP and lumbar DD are common already in adolescence, but very little is known of their association in young adults. Methods. Young adults belonging to a birth cohort (n=874) were invited to lumbar magnetic resonance imaging using a 1.5-T scanner. Data on LBP and functional limitations at the ages of 18, 19, and 21 years were used to cluster the subjects with respect to low back symptoms using latent class analysis. The prevalence and 95% confidence intervals of DD at 21 years and the sum score of DD at all lumbar levels were compared between the clusters. The contribution of DD and other imaging findings (herniations, anular tears, Modic changes, spondylolytic defects) to symptom severity was analyzed with logistic regression analysis. Results. Latent class analysis produced five clusters from the 554 subjects, ranging from a cluster where subjects (n=65) had been painful at all time points to an asymptomatic cluster (n=168). DD was more prevalent in the three most symptomatic clusters compared to the two least symptomatic ones. Similar findings were obtained for the DD sum scores. Lumbar DD was related to symptom severity independently of other degenerative findings. Moreover, moderately degenerated discs were more likely than mildly degenerated discs to be associated with the most severe low back symptoms. Conclusion. Intervertebral DD was associated with low back symptom severity among young adults, suggesting that the symptoms may have a discogenic origin at this age. However, DD was also found in one-third of asymptomatic subjects.


Journal of Telemedicine and Telecare | 2000

Initial experience with a wireless personal digital assistant as a teleradiology terminal for reporting emergency computerized tomography scans

Jarmo Reponen; Eero Ilkko; Lasse Jyrkinen; O. Tervonen; Jaakko Niinimäki; V Karhula; A Koivula

A new type of terminal device, a wireless personal digital assistant (PDA) based on a GSM digital cellular phone, was used to transmit computerized tomography scans of 21 patients to a neuroradiologist. All transmitted images were suitable for a preliminary consultation and in one case a final report could be made. In 18 cases the findings were compatible with the reference film reading performed later and in three cases there were minor differences of no clinical importance. Transmission of a single image lasted 1 min 30 s and the transmission of a complete brain scan (14 images) took on average 21 min. The total process of transmission and interpretation of a brain examination series took on average 40 min. In this pilot study the neuroradiologist gained essential information in 24% of the cases and beneficial information in 62%. The neuroradiologist considered that the image consultation saved a hospital visit in 15 cases (71%). Although PDA technology is at an early stage of development and has numerous limitations, it is likely that future technical improvements will allow easier clinical consultations for neurosurgeons and neurologists.


Spine | 2006

Determinants of spontaneous resorption of intervertebral disc herniations

Reijo A. Autio; Jaro Karppinen; Jaakko Niinimäki; Risto Ojala; Mauno Kurunlahti; Marianne Haapea; Heikki Vanharanta; Osmo Tervonen

Study Design. A follow-up of disc herniation (herniated nucleus pulposus [HNP]) resorption on magnetic resonance imaging (MRI). Objective. To assess the determinants of resorption of HNP. Summary of Background Data. Neovascularization in the outermost areas of HNP, presenting as an enhancing rim in gadolinium diethylenetriamine pentaacetic acid MR images, is thought to be a major determinant of spontaneous resorption of HNP. Methods. Patients with HNP-induced sciatica at baseline were rescanned at 2 months (N = 74) and after 12 months (N = 53). The volume of HNP (mm3), thickness (mm) and extent (%) of enhancement, and the degree of HNP migration (Komori classification) were analyzed. Repeated measures analysis of covariance was used in statistical analysis. Results. Significant resorption of HNP occurred from baseline to 2 months, although the resorption rate was more pronounced over the whole 1-year follow-up. Higher baseline scores of rim enhancement thickness, higher degree of HNP displacement in the Komori classification, and age category 41–50 years were associated with a higher resorption rate. Thickness of rim enhancement was a stronger determinant of spontaneous resorption than extent of rim enhancement. Clinical symptom alleviation occurs concordantly with a faster resorption rate. Conclusions. MRI is a useful prognostic tool for identifying patients with HNP-induced sciatica with a benign natural course.


Disability and Rehabilitation | 2009

Disability in end-stage knee osteoarthritis

Anna-Maija Kauppila; Eero Kyllönen; Paula Mikkonen; Pasi Ohtonen; Vesa Laine; Pertti Siira; Jaakko Niinimäki; Jari Arokoski

Objective. To examine the attributes of disability in end-stage knee osteoarthritis (OA) by analyzing the relationships between self-reported disability and objectively measured physical function after controlling pain, personal characteristic factors, and pathophysiological factors. Methods. The present study adopted a cross-sectional design. The subjects (n=88, aged 60–80 years) were scheduled for primary unilateral total knee arthroplasty (TKA) due to knee OA. Self-reported disability and pain were measured with the Western Ontario and McMaster Universities OA Index (WOMAC) and the RAND 36-item Health Survey 1.0 (RAND-36). Physical performance tests included a 15-m walk test and stair performance. Knee isometric muscle strength was measured. A clinical examination included analyses of comorbidity, body mass index (BMI), and a detailed knee examination: The flexion range of motion (ROM) was measured; the presence of varus/valgus malalignments and antero-posterior laxity was assessed. Radiographs were analyzed with the Kellgren-Lawrence grading scale. Results. In the linear regression model the WOMAC pain score, antero-posterior laxity of the knee, age, and BMI accounted for 54.8% of the variance in the WOMAC function score. In the bivariate analyses the WOMAC function score had a positive correlation with the 15-m walk (rs=0.32, p=0.003), stairs up (rs=0.40, p=0.001), and stairs down (rs=0.38, p=0.001) tests, and a negative correlation with RPT extension (rs=−0.45, p < 0.001) and RPT flexion (rs=−0.39, p=0.001) of the affected side and RPT flexion (rs=−0.39, p <0.001) of the contralateral side. The results of the physical performance tests also correlated with the RAND-36 Physical function (PF) score. Comorbid diseases and pain deteriorated the results of the physical performance tests and self-reported disability. Female gender deteriorated the results of the physical performance tests and the RAND-36 PF, but not the WOMAC function score. Malalignments, restriction in the flexion ROM of the knee, and the radiologic severity of knee OA did not affect self-reported disability. Conclusion. Pain, BMI, and antero-posterior laxity of the knee joint were major attributes of self-reported disability. The negative effect of comorbid diseases and female gender on health-related quality of life was significant. The results of objectively measured physical performance tests correlated with self-reported disability.

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Osmo Tervonen

Oulu University Hospital

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