Jyrki Nieminen - Academia.edu (original) (raw)

Papers by Jyrki Nieminen

Journal of Plastic, Reconstructive & Aesthetic Surgery

Orthopaedics & Traumatology: Surgery & Research, 2016

BACKGROUND Blood metal ion measurements have become a cornerstone in the surveillance of metal-on... more BACKGROUND Blood metal ion measurements have become a cornerstone in the surveillance of metal-on-metal (MoM) hip replacements. Interpretation of these levels in patients with bilateral MoM hip replacements, however, is challenging. We therefore asked (1) if there is a clinically significant change in whole blood (WB) Co or Cr levels in repeated WB assessment in patients operated on with bilateral ASR hip replacements, and (2) what proportion of patients has WB Co or Cr level below the previously established safe upper limits (SUL) (Co<5.0μg/L, Cr<7.4μg/L) in the repeated WB metal ion assessment. HYPOTHESIS We hypothesized that there is a significant difference between repeated Co and Cr level measurement performed within one year±4 months interval in patients with bilateral ASR hip replacements. MATERIALS AND METHODS We identified all patients (n=139) who had received bilateral ASR hip replacements (278 hips). Patients (n=76, 152 hips) who had undergone two blood metal ion measurements within eight to sixteen months' time interval were included in the study analysis. Study cohort included 38 patients with bilateral ASR hip resurfacings (mean age 53 years, median follow-up 4.6 years, median femoral diameter 51mm) and 38 patients with bilateral ASR XL total hip replacements (mean age 60 years, median follow-up 3.6 years, median femoral diameter 49mm). RESULTS There was no significant change in Co and Cr levels between the repeated measurements in the HR cohort. Both Co and Cr were significantly higher in the THR cohort in the repeated measurement (Co: 8.3μg/L vs. 12.6μg/L, Cr: 3.15μg/L vs. 3.4μg/L, both P<0.001). WB Co and Cr levels remained below SUL and within their initial values during a mean one-year measurement interval in the majority of patients with bilateral high risk HR device. In contrast to this, 21.1% of patients with THRs had WB Co ion levels exceeding the SUL in the first measurement. WB Co values significantly increased over the measurement interval in the THR group. DISCUSSION Annual blood metal ion measurement is not useful in patients with bilateral hip resurfacings who have undergone at least one preliminary screening including both metal ion measurement and cross-sectional imaging. It seems, however, to be beneficial in patients with bilateral high risk MoM THR. LEVEL OF EVIDENCE Level III (retrospective comparative study).

Acta Orthopaedica, 2021

Background and purpose — The proximal tibia is a rare site for metastatic bone disease and is a c... more Background and purpose — The proximal tibia is a rare site for metastatic bone disease and is a challenging anatomical site to manage due to the proximity to the knee joint and poor soft tissue envelope. We investigated implant survival and complications of different surgical strategies in the treatment of proximal tibia pathological fractures. Patients and methods — The study comprised a 4 medical center, retrospective analysis of 74 patients surgically treated for metastases of the proximal tibia. Patient records were reviewed to identify outcome, incidence, and type of complications as well as contributing factors. Results — Reconstruction techniques comprised cement-augmented osteosynthesis (n = 33), tumor prosthesis (n = 31), and total knee arthroplasty with long cemented stems (n = 10). Overall implant survival was 88% at 6 months and 1 year, and 67% at 3 years. After stratification by technique, the implant survival was 82% and 71% at 1 and 3 years with tumor prosthesis, 100% at 1 and 3 years with total knee arthroplasty, and 91% at 1 year and 47% at 3 years with osteosynthesis. Preoperative radiotherapy decreased implant survival. Complications were observed in 19/74 patients. Treatment complications led to amputation in 5 patients. Interpretation — In this study, the best results were seen with both types of prothesis reconstructions, with good implant survival, when compared with treatment with osteosynthesis. However, patients treated with tumor prosthesis showed an increased incidence of postoperative infection, which resulted in poor implant survival. Osteosynthesis with cement is a good alternative for patients with short expected survival whereas endoprosthetic replacement achieved good medium-term results.

© 2017 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation... more © 2017 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License (https://creativecommons.org/licenses/by-nc/3.0) DOI 10.1080/17453674.2017.1283846 Background and purpose — There has been increasing alarm regarding metal-on-metal (MoM) joint replacements leading to elevated levels of metal ions and adverse reactions to metal debris (ARMDs). There is little information available concerning the prevalence of and risk factors for these adverse reactions, except with MoM hip joint replacements. We determined the levels of metal ions in blood and the rate of revision due to ARMDs in patients treated with MoM hinge total knee arthroplasty (TKA). Patients and methods — 22 patients with TKAs and MoM hinge connecting mechanisms were studied for whole-blood chromium and cobalt levels at 6 months, 1 year, and/or ≥ 2 years after surgery. Possibl...

BMC Musculoskeletal Disorders, 2021

Background The purpose of this study was to determine the mid-term clinical, radiographic and hea... more Background The purpose of this study was to determine the mid-term clinical, radiographic and health-related quality of life (HRQoL) outcomes and define the survival rate in patients who had undergone revision total knee arthroplasty (TKA) using the single rotating hinged knee (RHK) design. Methods Between January 2004 and December 2013, 125 revision TKAs were performed at our institution using the single RHK implant. We conducted both a retrospective analysis of prospectively collected outcome data of these patients and a prospective follow-up study of all 39 living patients (41 knees). The follow-up phase included an optional extra follow-up visit, PROM questionnaires, and plain radiographs. Results The ten-year Kaplan-Meier survival rate of the revision RHK knees was 81.7% (95% CI 71.9–91.6%) with re-revision for any reason as the endpoint. Overall, 15 knees (12% of the total) underwent re-revision surgery during the follow-up. The median follow-up was 6.2 years (range, 0–12.7 ye...

Revue de Chirurgie Orthopédique et Traumatologique, 2016

Mesures sanguines répétées des ions métalliques chez les patients porteurs d'une prothèse totale ... more Mesures sanguines répétées des ions métalliques chez les patients porteurs d'une prothèse totale de hanche métal-métal (ARS TM) bilatérale ଝ Repeated metal ion measurement in patients with bilateral metal-on-metal (ASR TM) hip replacements

$Research paper thumbnail of P-436: The incidence of periprosthetic femoral fractures after total hip replacement in the Pirkanmaa Hospital District, Finland during 2002–2010$

European Geriatric Medicine, 2015

Calcified Tissue International, 2005

The objective of this study was to evaluate the influence of heterozygous inactivation of one all... more The objective of this study was to evaluate the influence of heterozygous inactivation of one allele of the type II collagen gene (Col2a1) on biomechanical properties and mineral density of bone under physical loading conditions. C57BL/6)TGN mice with heterozygous knockout (HZK) inactivation of Col2a1 gene and their nontransgenic littermate controls were housed in individual cages with running wheels for 9 and 15 months. The running activity of each mouse was monitored continuously throughout the experiment. Bone mineral density (BMD) of mice femora was measured using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computerized tomography (pQCT). Biomechanical properties were determined using three-point bending tests. Vertebral bone samples were prepared for quantitative polarized light microscopy and digital densitometry of proteoglycans. The concentration of total collagen and collagen cross-links were analyzed using high-performance liquid chromatograpy (HPLC).The average daily running distance was shorter for the HZK mice between the age of 4 and 15 months as compared with normal runners (P < 0.05). The ultimate breaking force was 14.8% and 23.6% (9 vs. 15 months) lower in HZK-runners than in wild-type runners. BMD of the femur was 6.1% lower in HZKrunners at the age of 9 months (P < 0.05). Physical activity increased cortical BMD in wild-type runners but not in the HZK runners at the age of 9 months. The collagen network of the HZK mice was less organized. There were only minor changes in BMD and mechanical and structural properties between sedentary HZK mice and their wild-type controls. Increased physical activity induced significantly lower bone density, mechanical properties, and organization of collagen fibers in male HZK mice. However, there were no major differences in biomechanical parameters between sedentary HZK and wild-type male mice. This suggests an important guiding role of collagen type II in bone remodelling and maturation.

Bone, 1995

Bone mineral density measurements using dual X-ray absorptiometry (DXA) are commonly expressed as... more Bone mineral density measurements using dual X-ray absorptiometry (DXA) are commonly expressed as areal density (g/cruZ). However, areal BMD (BMD .... I) is dependent on bone size and this can lead to erroneous interpretations of BMD values. We have previously presented a simple method for calculating apparent volumetric bone mineral density (BMD,o 0 using ancillary DXA-derived data. In the present study we tested the validity of our model using in vivo volumetric data obtained from magnetic resonance imaging (MRI) of lumbar vertebrae. BMDarea I and BMDvo I of L 3 were measured from sixteen pairs of identical twins (24 men, 8 women), aged 25-69 years. The dimensions of the lumbar vertebra L 3 were measured from MR images and BMD values were corrected for these dimensions. The DXA-derived apparent volumetric bone mineral density (BMDvo0 correlated moderately with MRI-derived BMDs (r values from 0.665 to 0.822). In contrast to BMD.r~at, BMDvol and MRIderived BMDs were not related to body size variables. All these volume-corrected BMDs diminished the erroneous effect of vertebral size on areal BMD. We conclude that the simple DXA-derived BMDvo ~ can be used for normalization of bone mineral density values in subjects of different body sizes, and especially in growing children.

$Research paper thumbnail of Treatment of pathological humerus shaft fractures with intramedullary nails with or without cement fixation$

Archives of Orthopaedic and Trauma Surgery, 2010

Bone metastasis is a severe complication for patients with cancer. Not only does it cause intract... more Bone metastasis is a severe complication for patients with cancer. Not only does it cause intractable pain and other clinical problems such as fracture after trivial injury, it also signifies that the malignant process is incurable. Since life expectancy of metastasised cancer patients has improved due to advanced oncological treatment but is still limited, appropriate surgical intervention has increased. This is a retrospective control study of 21 patients who underwent cemented intramedullary nailing for pathological fractures in the humeral shaft between 2005 and 2009 as compared to a historical control group of 19 patients that underwent locked intramedullary nailing for pathological fractures in the humeral shaft between 1999 and 2004. Four major outcomes were assessed, namely, pain relief, use of analgesics, recovery of function and rate of complication. Patients treated with cemented intramedullary nailing had better pain relief, less use of analgesics and better functional restoration immediately after surgical procedure when compared to the patients without cement fixing. The rate of complication did not differ between these two groups. Since surgery for metastases does not prolong life but improves the quality of life, the aim towards a short postoperative rehabilitation time is recommended. Cement fixation gives immediate stabilisation to the fracture site and thus allows less pain but full range of motion from the first postoperative day.

Acta Orthopaedica Scandinavica, 1995

Calcified Tissue International, 2008

Transgenic mice carrying an internally deleted human type II collagen gene (COL2A1) were used to ... more Transgenic mice carrying an internally deleted human type II collagen gene (COL2A1) were used to study bone growth and development. This mutation has previously been shown to disturb the development of collagen fibrils in articular cartilage, causing chondrodysplasia and osteoarthritis. Type II collagen expression in bones was investigated with immunohistochemistry. The development and mineralization of the skeleton and anthropometric measurements on bones were evaluated using X-rays and dynamic histomorphometry. Type II collagen was expressed in the cartilage of developing bones. The bones of transgenic mice were smaller compared with the controls. The bone mass remained almost unchanged in transgenic

Copyright © 2014 Minna Laitinen et al.This is an open access article distributed under the Creati... more Copyright © 2014 Minna Laitinen et al.This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Clear cell chondrosarcoma is a rare bone neoplasm with low-grade clinical course and the potential to metastasize to the skeleton and lungs.The aim of this report is to present a case that is extremely rare, but in accordance with the literature where the clear cell chondrosarcoma reportedly has a tendency for late metastases. In our patient the primary surgery was intralesional, since it was mistakenly interpreted as a benign tumour in the early 80s. The local recurrence and lung metastases occurred, however, 29 years after the initial treatment. The local recurrence was resected with wide margins, no additional surgery or oncological treatments were given, and two and half years postoperatively patient is doing well and there is no ...