Publications by authors named "Jochen G Hofstaetter"

50 Publications

Incidence of lateral femoral cutaneous nerve lesions after direct anterior approach primary total hip arthroplasty - a literature review.

Orthop Traumatol Surg Res 2021 May 4:102956. Epub 2021 May 4.

II. Orthopedic Department, Orthopedic Hospital Speising, Speisinger Str. 109, 1130 Vienna, Austria; Michael Ogon Laboratory for Orthopedic Research, Orthopedic Hospital Speising, Speisinger Str. 109, 1130 Vienna, Austria.

Introduction: Lesions of the lateral cutaneous femoral nerve are a reported complication of the direct anterior approach (DAA) for total hip arthroplasty (THA). Little is known about the incidence rates of this lesion. The goal of this study was to answer the following questions: (1) Is the true incidence rate of LFCN lesions after DAA THA known? (2) What are the reasons for the wide range of reported incidence rates in the literature? (3) Are surgeons increasingly aware of the significance of LFCN lesions?

Methods: A US Medical Library of Medicine database search was performed for DAA THA. In total, 1261 search results were screened for reported LFCN lesions.

Results: Forty-five studies were included reporting LFCN lesions rates of 0-83%. Subgroup analysis for studies with (group A, 6 studies, n=1113 cases) and without (group B, 39 studies n=16,741) primary focus on the LFCN lesions was performed. Incidence in group A ranged from 14.8-81% (mean 31%) and 0-83% (mean 3.8%) in group B. The difference between the groups was significant (p=0.005). No uniform and time sensitive definition of postoperative LFCN lesions was found in the literature. An analysis of the publication year and the discovered incidence rate showed an increase of incidence rates [r=0.521 (p<0.001, two-tailed)] over time.

Conclusion: Despite the absence of a uniform definition: LFCN lesions after DAA THA are a frequent and, in the past, often underestimated complication.

Level Of Evidence: IV; systematic review of level II to level IV studies.
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http://dx.doi.org/10.1016/j.otsr.2021.102956DOI Listing
May 2021

Reconstruction of Proximal Metaphyseal Femoral Defects Using Trabecular Metal Augments in Revision Total Hip Arthroplasty.

Arthroplast Today 2021 Apr 14;8:216-221. Epub 2021 Apr 14.

Michael Ogon Laboratory for Orthopaedic Research, Orthopaedic Hospital Vienna-Speising, Vienna, Austria.

Porous tantalum augments are widely used in revision total hip arthroplasty for the reconstruction of severe bone defects. Here, we present the first 3 cases who underwent femoral revision arthroplasty using standard distal femoral and proximal tibial porous tantalum cones to reconstruct severe bone loss in the proximal femur. Cones were inserted press fit, followed by implantation of a cemented revision stem in all cases. After a mean follow-up period of 15.8 months, all patients showed an improved Harris-Hip-Score and no radiological signs of subsidence or loosening. Porous tantalum cones may be an option in the reconstruction of severe femoral defects in revision total hip arthroplasty. The shape of the tantalum cones should be optimized for the use in the proximal femur.
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http://dx.doi.org/10.1016/j.artd.2021.03.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8079334PMC
April 2021

Impact of the 1st and 2nd Wave of the COVID-19 Pandemic on Primary or Revision Total Hip and Knee Arthroplasty-A Cross-Sectional Single Center Study.

J Clin Med 2021 Mar 18;10(6). Epub 2021 Mar 18.

Michael Ogon Laboratory for Orthopaedic Research, Orthopaedic Hospital Vienna-Speising, Speisinger Straße 109, 1130 Vienna, Austria.

The aim of this study was to evaluate the number of primary and revision total joint arthroplasties (TJA/rTJA) in 2020 compared to 2019. Specifically, the first and the second waves of the COVID-19 pandemic were evaluated as well as the pre-operative COVID-19 test. A cross-sectional single-center study of our prospectively maintained institutional arthroplasty registry was performed. The first COVID-19 wave and the second COVID-19 wave led to a socioeconomic lockdown in 2020. Performed surgeries, cause of revision, age, gender, and American Society of Anesthesiologists-level were analyzed. Preoperative COVID-19 testing was evaluated and nationwide COVID-19 data were compared to other countries. In 2020, there was a decrease by 16.2% in primary and revision TJAs of the hip and knee compared to 2019. We observed a reduction of 15.8% in primary TJAs and a reduction of 18.6% on rTJAs in 2020 compared to 2019. There is an incline in total hip arthroplasties (THAs) and a decline in total knee arthroplasties (TKAs) comparing 2019 to 2020. During the first wave, there was a reduction in performed primary TJAs of 86%. During the second wave, no changes were observed. This is the first study quantifying the impact of the COVID-19 pandemic on primary and revision TJAs regarding the first and second wave.
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http://dx.doi.org/10.3390/jcm10061260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8003209PMC
March 2021

Analysis of Culture Positive First and Second Stage Procedures in Periprosthetic Knee and Hip Joint Infections.

J Arthroplasty 2021 Jun 2;36(6):2158-2164. Epub 2021 Feb 2.

Michael Ogon Laboratory for Orthopaedic Research, Orthopaedic Hospital Vienna-Speising, Vienna, Austria; 2nd Department, Orthopaedic Hospital Vienna-Speising, Vienna, Austria.

Background: A positive microbiological result at reimplantation may lead to a failed 2-stage revision arthroplasty in the treatment of periprosthetic joint infections. Little is known about changes in microbiological spectrum and resistance pattern between culture positive first and second stage procedures in revision knee and hip arthroplasty.

Methods: Between January 2011 and December 2019, we performed 327 two-stage revision arthroplasties on 312 patients. There were 37 of 312 (11.9%) patients (20 hips/17 knees) who had a positive microbiological culture during the first and second stage procedure. We analyzed the microbiological spectrum, antimicrobial resistance pattern, and clinical outcome of culture positive first and second stage procedures as well as subsequent re-revisions.

Results: Re-revision was necessary in 40.5% (15/37) of patients with culture positive first and second stage procedure at a median follow-up of 3.5 years. We found microbiological changes in 83.8% (31/37) of patients between the first and second stage and in 88.9% (8/9) between the second stage and subsequent culture positive re-revision. Polymicrobial infections were found in 21.6% (8/37) of first and in 16.2% (6/37) of second stage procedures. In 27% (10/37) of patients, microorganisms persisted between the first and second stage procedure. The antimicrobial resistance pattern changed in 60% of persistent microorganisms between the first and second stage procedure.

Conclusion: Changes in microbiological spectrum and resistance pattern are common between culture positive first and second stage procedures as well as subsequent re-revisions. This has to be considered in the antimicrobial treatment of periprosthetic joint infections.
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http://dx.doi.org/10.1016/j.arth.2021.01.074DOI Listing
June 2021

No Role of Osteocytic Osteolysis in the Development and Recovery of the Bone Phenotype Induced by Severe Secondary Hyperparathyroidism in Vitamin D Receptor Deficient Mice.

Int J Mol Sci 2020 Oct 27;21(21). Epub 2020 Oct 27.

Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria.

Osteocytic osteolysis/perilacunar remodeling is thought to contribute to the maintenance of mineral homeostasis. Here, we utilized a reversible, adult-onset model of secondary hyperparathyroidism to study femoral bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) based on quantitative backscattered electron imaging. Male mice with a non-functioning vitamin D receptor (VDR) or wild-type mice were exposed to a rescue diet (RD) (baseline) and subsequently to a low calcium challenge diet (CD). Thereafter, VDR mice received either the CD, a normal diet (ND), or the RD. At baseline, BMDD and OLS characteristics were similar in VDR and wild-type mice. The CD induced large cortical pores, osteomalacia, and a reduced epiphyseal average degree of mineralization in the VDR mice relative to the baseline (-9.5%, < 0.05 after two months and -10.3%, < 0.01 after five months of the CD). Switching VDR mice on the CD back to the RD fully restored BMDD to baseline values. However, OLS remained unchanged in all groups of mice, independent of diet. We conclude that adult VDR animals on an RD lack any skeletal abnormalities, suggesting that VDR signaling is dispensable for normal bone mineralization as long as mineral homeostasis is normal. Our findings also indicate that VDR mice attempt to correct a calcium challenge by enhanced osteoclastic resorption rather than by osteocytic osteolysis.
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http://dx.doi.org/10.3390/ijms21217989DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7662929PMC
October 2020

Detection and imaging of gadolinium accumulation in human bone tissue by micro- and submicro-XRF.

Sci Rep 2020 04 14;10(1):6301. Epub 2020 Apr 14.

TU Wien, Atominstitut, Stadionallee 2, Vienna, 1020, Austria.

Gadolinium-based contrast agents (GBCAs) are frequently used in patients undergoing magnetic resonance imaging. In GBCAs gadolinium (Gd) is present in a bound chelated form. Gadolinium is a rare-earth element, which is normally not present in human body. Though the blood elimination half-life of contrast agents is about 90 minutes, recent studies demonstrated that some tissues retain gadolinium, which might further pose a health threat due to toxic effects of free gadolinium. It is known that the bone tissue can serve as a gadolinium depot, but so far only bulk measurements were performed. Here we present a summary of experiments in which for the first time we mapped gadolinium in bone biopsy from a male patient with idiopathic osteoporosis (without indication of renal impairment), who received MRI 8 months prior to biopsy. In our studies performed by means of synchrotron radiation induced micro- and submicro-X-ray fluorescence spectroscopy (SR-XRF), gadolinium was detected in human cortical bone tissue. The distribution of gadolinium displays a specific accumulation pattern. Correlation of elemental maps obtained at ANKA synchrotron with qBEI images (quantitative backscattered electron imaging) allowed assignment of Gd structures to the histological bone structures. Follow-up beamtimes at ESRF and Diamond Light Source using submicro-SR-XRF allowed resolving thin Gd structures in cortical bone, as well as correlating them with calcium and zinc.
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http://dx.doi.org/10.1038/s41598-020-63325-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7156386PMC
April 2020

Biomechanical and Bone Material Properties of Schnurri-3 Null Mice.

JBMR Plus 2019 Nov 11;3(11):e10226. Epub 2019 Sep 11.

1st Medical Department Hanusch Hospital Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling Vienna Austria.

is an essential regulator of postnatal skeletal remodeling. Shn3-deficient mice (Shn3-/-) have high bone mass; however, their bone mechanical and material properties have not been investigated to date. We performed three-point bending of femora, compression tests of L3 vertebrae. We also measured intrinsic material properties, including bone mineralization density distribution (BMDD) and osteocyte lacunae section (OLS) characteristics by quantitative backscatter electron imaging, as well as collagen cross-linking by Fourier transform infrared microspectroscopy of femora from Shn3-/- and WT mice at different ages (6 weeks, 4 months, and 18 months). Moreover, computer modeling was performed for the interpretation of the BMDD outcomes. Femora and L3 vertebrae from Shn3-/- aged 6 weeks revealed increased ultimate force (2.2- and 3.2-fold, < .01, respectively). Mineralized bone volume at the distal femoral metaphysis was about twofold (at 6 weeks) to eightfold (at 4 and 18 months of age) in Shn3-/- ( < .001). Compared with WT, the average degree of trabecular bone mineralization was similar at 6 weeks, but increased at 4 and 18 months of age (+12.6% and +7.7%, < .01, respectively) in Shn3-/-. The analysis of OLS characteristics revealed a higher OLS area for Shn3-/- versus WT at all ages (+16%, +23%, +21%, respectively, < .01). The collagen cross-link ratio was similar between groups. We conclude that femora and vertebrae from Shn3-/- had higher ultimate force in mechanical testing. Computer modeling demonstrated that in cases of highly increased bone volume, the average degree of bone matrix mineralization can be higher than in WT bone, which was actually measured in the older Shn3-/- groups. The area of 2D osteocyte lacunae sections was also increased in Shn3-deficiency, which could only partly be explained by larger remnant areas of primary cortical bone. © 2019 The Authors. published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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http://dx.doi.org/10.1002/jbm4.10226DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6874182PMC
November 2019

The role of the subchondral layer in osteonecrosis of the femoral head: analysis based on HR-QCT in comparison to MRI findings.

Acta Radiol 2019 Apr 6;60(4):501-508. Epub 2018 Jul 6.

1 Department of Orthopedics, Medical University of Vienna, 1090 Vienna, Austria.

Background: Non-traumatic avascular osteonecrosis of the femoral head (ONFH) is a severe disease causing destruction of the hip joint, often necessitating total hip arthroplasty (THA) even in young patients. Magnetic resonance imaging (MRI) is commonly used for diagnosis of ONFH, but provides limited insight into the subchondral bone microstructure.

Purpose: To analyze routine MRI findings in comparison to high-resolution quantitative computed tomography (HR-QCT) with a special focus on the subchondral layer and to estimate the importance of differences determining the indication for THA.

Material And Methods: Twelve patients with ONFH were included before THA. Preoperative MRI and HR-QCT of the retrieved femoral heads were aligned using a registration algorithm. Pathological findings and trabecular bone parameters in matched areas were analyzed by two readers. McNemar, marginal homogeneity test, and Pearson's correlation coefficient were used for comparison.

Results: Subchondral delamination was found in nine cases on HR-QCT, but missed or underestimated in all but one case on MRI ( P = 0.016). Chondral discontinuity was found in all cases on HR-QCT and in two cases on MRI ( P = 0.016). Areas of complete bone resorption on HR-QCT were linked to high signal intensity on 3D gradient-echo MRI sequences with water-selective excitation, while there was no correlation between trabecular bone parameters and MRI signal intensities in other areas ( P = 0.304).

Conclusion: Subchondral delamination, subchondral resorption, and chondral discontinuity are found frequently in advanced stages of ONFH. These lesions tend to be underestimated on conventional MRI. Our results support the importance of CT imaging in the evaluation of ONFH.
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http://dx.doi.org/10.1177/0284185118786070DOI Listing
April 2019

How frequent is osteogenesis imperfecta in patients with idiopathic osteoporosis?: Case reports.

Medicine (Baltimore) 2017 Sep;96(35):e7863

Ludwig Boltzmann Institute of Osteology, Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital Orthopedic Hospital of Speising, Pediatric Department, Vienna, Austria Ibn Zohr Institute of Radiology and Imaging studies, Tunis, Tunisia Pediatric Orthopedic Surgery, Children's Hospital of Tunis, Tunis, Tunisia Department of Foot and Ankle Surgery, Neuroorthopaedics and Systemic Disorders, Pediatric Orthopedic Institute n.a. H. Turner, Saint Petersburg, Russia Axial Skeleton and Neurosurgery Department, Restorative Traumatology and Orthopaedics, Ilizarov Center, Kurgan, Russia Institute of Medical Chemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria.

Rationale: The term idiopathic osteoporosis itself is quite a non-specific disease label, which fails to address the etiological understanding. Bone mineral density alone is not a reliable parameter to detect patients at high risk of fracture. The diversity of the clinical phenotypes of discolored teeth, blueness of the sclera, back and joint pain, cardiovascular disease, Diabetes type II, hearing problems and a long list of orthopedic problems are have to be considered.

Patients Concerns: Our study has been designed in accordance with the clinical and radiological phenotype of eleven index cases with the provisional diagnosis of OI, which was followed by genotypic confirmation. This was followed by the invitation of siblings, parents, grandparents and other relatives to participate in the interviews, and to discuss the impact of the diagnosis. Proper collaboration with these families facilitated the process to identify other subjects with a history of fractures and other deformities/disabilities which were seemingly correlated to heritable connective tissue disorder. In total, 63 patients (27 children and 36 parents/grandparents and relatives) were enrolled in the study. Two groups of children were not included in our study. We excluded children with incomplete documentation and children who manifested de novo mutation. The term idiopathic osteoporosis (IOP) has been given to these families in other Institutes and was considered as a definite diagnosis. IOP was solely based on T scores, BMD and certain laboratory tests. Surprisingly, no single adult patient underwent clinical and or radiological phenotypic characterization.

Diagnoses: A constellation of significant disease associations with osteoporotic fracture risk have been encountered. The index cases showed mutations in COL1A1 (17q21.31.q22) and COL1A2 (7q22.1), the genes encoding collagen type I. The phenotype/genotype confirmation in 11 children was the key factor to boost our research and to re-consult each family. Comprehensive clinical and radiological phenotypic documentation has been applied to most of other family subjects who principally received the diagnosis of IOP.

Interventions: All adult patients had normal serum calcium and only three patients showed an average of low serum phosphate of 0.7-0.61 mmol/l. Serumcrosslaps in six parents was in the average of (2.9-3.8 nM) and PTH levels were normal in all patients (the average showed 8.73 pg/ml).

Outcomes: Our efforts to minimize and constrain the usage of the term idiopathic osteoporosis and to understand the sequence of pathological events that occurred in these families were emphasized. These efforts evolved into a remarkable and unique constellation of clinical findings. Strikingly, fracture represented a portion in a series of skeletal and extra-skeletal deformities and abnormalities which are all correlated to connective tissue disorder. This was achieved mainly through comprehensive phenotype/genotype confirmation, followed by scrutinizing the records of each family, clinical examination of the adults and revising the archives of our Hospitals and other Institutes.

Lessons: The sequence of diverse pathological events recorded within each family would be almost incomprehensible without a proper etiological understanding of the natural history of each child/family deformity that led to their occurrences. We wish to stress that, our current study is just an attempt to cover only a tiny fraction of the tip of the iceberg and to profoundly explore one of the most under-estimated causes of idiopathic osteoporosis.
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http://dx.doi.org/10.1097/MD.0000000000007863DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5585491PMC
September 2017

Increased zinc accumulation in mineralized osteosarcoma tissue measured by confocal synchrotron radiation micro X-ray fluorescence analysis.

Xray Spectrom 2017 Jan-Feb;46(1):56-62. Epub 2016 Dec 21.

Atominstitut TU Wien Vienna Austria.

Abnormal tissue levels of certain trace elements such as zinc (Zn) were reported in various types of cancer. Little is known about the role of Zn in osteosarcoma. Using confocal synchrotron radiation micro X-ray fluorescence analysis, we characterized the spatial distribution of Zn in high-grade sclerosing osteosarcoma of nine patients (four women/five men; seven knee/one humerus/one femur) following chemotherapy and wide surgical resection. Levels were compared with adjacent normal tissue. Quantitative backscattered electron imaging as well as histological examinations was also performed. On average, the ratio of medians of Zn count rates (normalized to calcium) in mineralized tumor tissue was about six times higher than in normal tissue. There was no difference in Zn levels between tumor fraction areas with a low fraction and a high fraction of mineralized tissue, which were clearly depicted using quantitative backscattered electron imaging. Moreover, we found no correlation between the Zn values and the type of tumor regression according to the Salzer-Kuntschik grading. The underlying mechanism of Zn accumulation remains unclear. Given the emerging data on the role of trace elements in other types of cancer, our novel results warrant further studies on the role of trace elements in bone cancer. Copyright © 2016 The Authors. published by John Wiley & Sons Ltd.
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http://dx.doi.org/10.1002/xrs.2727DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5299496PMC
December 2016

Spine malformation complex in 3 diverse syndromic entities: Case reports.

Medicine (Baltimore) 2016 Dec;95(50):e5505

Ludwig Boltzmann Institute of Osteology, the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital Orthopaedic Hospital of Speising, Paediatric Department Department of Pediatrics, Kaiser-Franz-Josef Spital, Vienna, Austria Axial Skeleton and Neurosurgery Department, Restorative Traumatology and Orthopaedics, Ilizarov Center, Kurgan, Russia Pediatric Orthopedic Institute n.a. H. Turner, Department of Foot and Ankle Surgery, Neuroorthopaedics and Systemic Disorders, Saint-Petersburg, Russia Institute of Medical Chemistry, Medical University of Vienna, Austria.

Rationale: Clinical and radiographic phenotypic characterizations were the base line tool of diagnosis in 3 syndromic disorders in which congenital cervico-thoracic kyphosis was the major deformity.

Patients Concerns: Directing maximal care toward the radiographic analysis is not only the axial malformation but also toward the appendicular abnormalities was our main concern. We fully documented the diversity of the spine phenotypic malformation complex via the clinical and radiographic phenotypes.

Diagnoses: We established the diagnosis via phenotypic/genotypic confirmation in 3 diverse syndromic entities namely acampomelic campomelic dysplasia, Larsen syndrome and Morquio syndrome type A (mucopolysaccharidosis type IV A).

Interventions: Surgical interventions have been carried out in the Larsen syndrome and Morquio syndrome type A, resepectively.

Outcomes: The earliest the diagnosis is, the better the results are. The necessity to diagnose children in their first year of life has many folds, firstly the management would be in favor of the child's growth and development and secondly, the prognosis could be clearer to the family and the medical staff as well. Our current paper is to sensitize paediatricians, physicians and orthopedic surgeons regarding the necessity to detect the aetiological understanding in every child who manifests a constellation of malformation complex.

Lesons: Scoliosis and kyphosis/kyphoscoliosis are not a diagnosis in themselves. Such deformities are mostly a symptom complex correlated to dozens of types of syndromic associations. The rate curve progression and the final severity of congenital spine tilting are related to 3 factors: (a) the type of vertebral malformation present, (b) the patient's phenotype, and
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http://dx.doi.org/10.1097/MD.0000000000005505DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5268028PMC
December 2016

Can Multiple Hereditary Exostoses Overlap With Mesomelic Dysplasia?

J Clin Med Res 2016 Aug 1;8(8):605-9. Epub 2016 Jul 1.

Institute of Medical Chemistry, Medical University of Vienna, Austria.

Background: We studied an unusual combination of severe short stature, mesomelia (Leri-Weill dyschondrosteosis syndrome), and multiple exostosis in several family subjects over three generations. The pattern of inheritance was compatible with autosomal dominant.

Methods: Of 21 affected members over three generations, shortness of stature, associated with mesomelia resembling Leri-Weill dyschondrosteosis syndrome with no exostoses was evident in three family subjects. The rest of the family subjects manifested with normal height, and yet multiple exostoses. In this family, the skeletal manifestations were sufficiently variable for the presentation to be with either short stature or scoliosis, a Madelung' deformity, or with severe hallux valgus associated with exostosis and with Leri-Weill dyschondrosteosis syndrome.

Results: Subjects with structural chromosomal aberrations of the proband IV-7, who manifested with normal height but with multiple exostoses were excluded via 20 CAG-banded mitoses (there were no microdeletions or microduplication after performing Array-CGH-analysis). In addition, DNA examination for subject IV-8 (male cousin of the proband showed short stature and Leri-Weill dyschondrosteosis syndrome) revealed no evidence of SHOX deletions.

Conclusion: We described a multigenerational non-consanguineous North African family , in which mesomelic dysplasia, whose clinical and radiological phenotypes resembled dyschondrosteosis, was a prominent feature in three family subjects. Multiple exostoses were evident in several other family subjects (most were with normal height). We would like to emphasize the variability in the phenotypic expression of multiple exostosis, especially the confusion that might arise when the condition appears both clinically and radiologically to be more complicated, and the overall picture might then be overlapped with one of the other bone dysplasias such as Leri-Weill dyschondrosteosis syndrome.
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http://dx.doi.org/10.14740/jocmr2593wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931807PMC
August 2016

What Sport Activity Levels Are Achieved in Patients After Resection and Endoprosthetic Reconstruction for a Proximal Femur Bone Sarcoma?

Clin Orthop Relat Res 2017 Mar;475(3):817-826

Department of Orthopaedic Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.

Background: Limited information is available about sports activities of survivors after resection and reconstruction of primary malignant bone tumors with megaprostheses. Because patients often ask what activities are possible after treatment, objective knowledge about sports activities is needed to help assess the risks of sports participation and to help guide patients' expectations.

Questions/purposes: The aims of this study were to evaluate (1) what proportion of patients with proximal-femoral megaprostheses placed as part of tumor reconstructions can perform sports; (2) what activity levels they achieved; and (3) whether sports activity levels are associated with an increased likelihood of revision.

Methods: This retrospective study considered all 27 living patients in our institutional tumor registry with enduring proximal-femoral reconstructions performed more than 5 years ago who were between the ages of 11 and 49 years at the time of the reconstruction; seven were lost to followup and one was excluded because of paraplegia as a result of a car accident and another because of senile dementia; another two were excluded from statistics because of growing prostheses and skeletal immaturity at the time of followup, leaving 16 (11 male, five female) for analysis. Their mean age was 26 ± 12 years (range, 11-49 years) at surgery, and the mean followup was 18 ± 7 years (range, 5-27 years). Types of sports, frequency per week, duration of each sports session as well as the UCLA and modified Weighted Activity Score were assessed retrospectively by an independent assessor a median of 18 years (range, 5.3-27 years) after surgery.

Results: Patients recalled that preoperatively 14 were practicing sports 5 (± 4) hours/week. At followup, 11 of the patients were practicing one or more sports activities 2 (± 3) hours/week on a regular basis. The preoperative UCLA and modified Weighted Activity Score levels of 9 and 6 fell to levels of 6 (p = 0.005) and 3 (p = 0.025), respectively, at followup. With the numbers of patients available for study, we could not determine that prosthetic failures were associated with sport activity levels.

Conclusions: Patients who survive primary malignant bone tumors in the proximal femur reconstructed by megaprostheses are able to perform some sports activities. The estimates of activity levels made in this study probably are best-case estimates, given that some patients were lost to followup; patients unaccounted for might not be doing as well as those represented here. Also, the degree to which sports participation influences implant durability remains, for the most part, unanswered; studies with more patients and longer followup will be needed to determine to what degree prosthesis survivorship relates to sporting activity levels. Most patients perform low-impact sports and at a lower level than they had preoperatively. Because this is a preliminary study of a select group of patients, further information is necessary to weight the benefits of higher sports activity levels against potential risks. If this can be confirmed in a larger number of patients, the information may guide surgeons in their discussion with patients preoperatively and give them some objective assessment of what to expect regarding sports activities.

Level Of Evidence: Level IV, therapeutic study.
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http://dx.doi.org/10.1007/s11999-016-4790-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5289166PMC
March 2017

What sports activity levels are achieved in patients with modular tumor endoprostheses of osteosarcoma about the knee?

Clin Orthop Relat Res 2015 Mar;473(3):847-54

Department of Orthopaedic Surgery, Medical University of Vienna, 1090, Vienna, Austria.

Background: Advances in multimodal treatment have improved survival of patients with nonmetastatic osteosarcoma. At the same time, implant design has improved the outcomes of limb salvage with modular endoprostheses. However, little is known about sports activity in long-term survivors with osteosarcoma.

Questions/purposes: We wanted to evaluate (1) sports activity levels in long-term survivors of osteosarcoma about the knee who received a modular tumor endoprosthesis; (2) to determine if activity level changed over time from initial reconstruction or (3) was predicted from sports activity level before diagnosis; and (4) if complications that occurred affected sports or contributed to prosthetic failures.

Methods: Between 1995 and 2005, we treated 120 patients for osteosarcoma about the knee with resection and modular endoprosthetic reconstruction; of those, 25 (21%) have died, six (5%) had an amputation, 39 (32%) did not speak German and so were ineligible, and 14 (12%) were either lost to followup or refused to participate, leaving 27 patients (14 females, 13 males; median age 19 years [range, 12-60 years); average followup 11 ± 4 years) (54% of the living, German-speaking cohort) for this analysis. Tumors were located in the distal femur (n = 16) and the proximal tibia (n = 11). Sports participation as well as the UCLA Activity Score and the modified Weighted Activity Score were assessed retrospectively. Moreover, postoperative complications were evaluated.

Results: Before the diagnosis of osteosarcoma and 1, 3, and 5 years and at the latest followup, respectively, after their reconstructions, 24 (89%), nine (33%), 20 (74%), and 24 patients (89%) were able to perform sports activities. There was a reduction in high-impact activities. Those patients with followup longer than 5 years had no changes in sports activity at their latest followup. Patients who had higher levels of sports activity levels before surgery generally had higher levels of activity at last followup (UCLA Activity Score: r = 0.62, p < 0.0005; modified Weighted Activity Score r = 0.49, p < 0.01). Fourteen patients (51%) underwent revision surgery. With the numbers available, complications had no effect on sports activity. No sports activity-related complications were found.

Conclusions: Some long-term survivors of osteosarcoma can achieve high levels of sports activity. Preoperative activity levels seem to influence the postoperative activity levels. This information is important to give realistic expectations for long-term survivors of osteosarcoma of the knee.

Level Of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.1007/s11999-014-3788-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317435PMC
March 2015

Incidence and management of hip dislocation in tumour patients with a modular prosthesis of the proximal femur.

Int Orthop 2014 Aug 29;38(8):1677-84. Epub 2014 May 29.

Department of Orthopaedic Surgery, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria,

Purpose: Little data is available about the incidence and especially the management of hip dislocation following the implantation of modular tumor prostheses of the proximal femur. In this retrospective single-centre study we assessed the incidence of hip dislocation following implantation of a proximal femoral modular prosthesis as well as the success of the subsequent surgical or non-surgical treatment in tumor patients.

Methods: Between 1982 and 2008, 166 tumor patients received a modular prosthesis of the proximal femur at our institution. The average age at the time of surgery was 50 ± 20 years (range, six to 84 years). An additional pelvic reconstruction was done in 14 patients. An artificial band for soft tissue reconstruction of the hip was used in 19 patients. The average time of follow-up was 46 ± 64 months (range, one to 277 months).

Results: The overall dislocation rate after proximal femoral replacement was 13% after a mean time of seven ± eight months (range, 0.3-33 months) after surgery. Between 1982 and 1986 the dislocation rate was 33% and declined to 9% in subsequent years (1987-2008). Patients who had received an additional pelvic reconstruction had a three fold higher dislocation rate (p <0.05). Patients with closed reduction had a 58% (eight of 12) re-dislocation rate compared to 11% (one of nine) for open reduction (p = 0.0357).

Conclusions: Dislocation of a modular prosthesis of the proximal femur is a common complication, especially in cases with additional pelvic resection with extensive bone and soft-tissue defects. Open surgical management may be more effective in preventing re-dislocation than closed reduction and bracing alone.
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http://dx.doi.org/10.1007/s00264-014-2376-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4115123PMC
August 2014

Glycophenotyping of osteoarthritic cartilage and chondrocytes by RT-qPCR, mass spectrometry, histochemistry with plant/human lectins and lectin localization with a glycoprotein.

Arthritis Res Ther 2013 Oct 4;15(5):R147. Epub 2013 Oct 4.

Introduction: This study aimed to characterize the glycophenotype of osteoarthritic cartilage and human chondrocytes.

Methods: Articular knee cartilage was obtained from nine osteoarthritis (OA) patients. mRNA levels for 27 glycosyltransferases were analyzed in OA chondrocytes using RT-qPCR. Additionally, N- and O-glycans were quantified using mass-spectrometry. Histologically, two cartilage areas with Mankin scores (MS) either ≤ 4 or ≥ 9 were selected from each patient representing areas of mild and severe OA, respectively. Tissue sections were stained with (1) a selected panel of plant lectins for probing into the OA glycophenotype, (2) the human lectins galectins-1 and -3, and (3) the glycoprotein asialofetuin (ASF) for visualizing β-galactoside-specific endogenous lectins.

Results: We found that OA chondrocytes expressed oligomannosidic structures as well as non-, mono- and disialylated complex-type N-glycans, and core 2 O-glycans. Reflecting B4GALNT3 mRNA presence in OA chondrocytes, LacdiNAc-terminated structures were detected. Staining profiles for plant and human lectins were dependent on the grade of cartilage degeneration, and ASF-positive cells were observed in significantly higher rates in areas of severe degeneration.

Conclusions: In summary, distinct aspects of the glycome in OA cartilage are altered with progressing degeneration. In particular, the alterations measured by galectin-3 and the pan-galectin sensor ASF encourage detailed studies of galectin functionality in OA.
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http://dx.doi.org/10.1186/ar4330DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978707PMC
October 2013

Broad spectrum of skeletal malformation complex in patients with cleidocranial dysplasia syndrome: radiographic and tomographic study.

Clin Med Insights Arthritis Musculoskelet Disord 2013 19;6:45-55. Epub 2013 Aug 19.

Ludwig Boltzmann Institute of Osteology, Hanusch Hospital of WGKK and AUVA Trauma Center Meidling, First Medical Department, Hanusch Hospital, Vienna, Austria. ; Orthopedic Hospital of Speising, Pediatric Department, Vienna, Austria.

Purpose: Cleidocranial dysplasia is an autosomal dominant disorder characterized by defective ossification of the intramembraneous ossification (primarily the clavicles, cranium, and pelvis), and it is caused by mutations in the RUNX2 gene that is responsible for osteoblast differentiation. Spine deformities were of progressive nature and considered to be the major orthopedic abnormalities encountered in our practice in patients with cleidocranial dysplasia. We aimed to further delineate the underlying spine pathology and its etiological understanding. Extraspinal deformities were dealt with respectively.

Material And Methods: In this paper, we describe 7 patients who were consistent with the phenotypic and the genotypic characterization of cleidocranial dysplasia. Reformatted computed tomography (CT) scans have been applied in several instances to further understand the underlying pathology of progressive spine tilting. Radiographs were sufficient to illustrate other skeletal malformations.

Results: Anatomical survey demonstrates that a broad spectrum of frequently unrecognized orthopedic aberrations were encountered. We believe that torticollis has evolved in connection with the persistence of synchondrosis of the skull base and the upper cervical spine and these are strongly correlated to the well-known pathology of posterior occipital synchondrosis. Similarly, scoliosis and kyphoscoliosis resulted from the pathologic aberration of the cartilaginous stage of disrupted embryological development. All our results are discussed for the first time. Coxa vara, patellar dysplasia, and genu valgum were observed as extraspinal deformities.

Conclusion: This paper includes for the first time the anatomical analysis of the malformation complex of the craniocervical and the entire spine in patients with cleidocranial dysplasia. Reformatted CT scan was the modality of choice. We were able to illustrate that the persistence of skull base and the cervical spine synchondrosis were correlated with the pathological mechanism of the posterior occipital synchondrosis. Therefore, injuries to the craniocervical region in these patients might lead to a wide range of dreadful complications, ranging from complete atlanto-occipital or atlanto-axial dislocation to nondisplaced occipital condyle avulsion fractures with the possibility of morbid and or mortal outcome. On the other hand, the persistence of a cartilaginous spine was the reason behind the progressive spine tilting. This pathological form can be considered as a notoriously unpredictable malformation complex. The value of presenting these patients is to demonsterate that the genotype is not a precise index to assess the severity and the natural history of the phenotype.
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http://dx.doi.org/10.4137/CMAMD.S11933DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3762605PMC
September 2013

Radiographic and tomographic analysis in patients with stickler syndrome type I.

Int J Med Sci 2013 3;10(9):1250-8. Epub 2013 Aug 3.

Ludwig Boltzmann Institute of Osteology, at the Hanusch Hospital of WGKK and, AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Vienna, Austria.

Objective: To further investigate the underlying pathology of axial and appendicular skeletal abnormalities such as painful spine stiffness, gait abnormalities, early onset osteoarthritis and patellar instability in patients with Stickler syndrome type I. Radiographic and tomographic analyses were organized.

Methods: From a series of Stickler syndrome patients followed from early life to late childhood. Ten patients (6 boys and four girls of different ethnic origins were consistent with the diagnosis of Stickler syndrome type I ). Phenotypic characterization was the baseline tool applied for all patients and genotypic correlation was performed on four families

Results: A constellation of axial abnormalities namely; anterolateral ossification of the anterior longitudinal spinal ligament with subsequent fusion of two cervical vertebrae, early onset Forestier disease (progressive spinal hyperostosis with subsequent vertebral fusion on top of bridging osteophytes and "Bamboo-like spine" resembling ankylosing spondylitis) and severe premature spine degeneration were evident. Appendicular abnormalities in connection with generalized epiphyseal dysplasia were the underlying aetiology in patients with Intoeing gait and femoral anteversion, early onset severe osteoarthritis of the weight bearing joint. Remarkable trochleo-patellar dysplasia secondary to severe osteoarthritis causing effectively the development of patellar instability was additional pathology. Mutation of COL2A1 has been confirmed as the causative gene for Stickler syndrome type I CONCLUSION: We concluded that conventional radiographs and the molecular determination of a COL2A1 in patients with (Stickler syndrome type I) are insufficient tools to explain the reasons behind the tremendous magnitude of axial and appendicular skeletal abnormalities. We were able to modify the criteria of the clinical phenotype as designated by Rose et al in accordance with the novel axial and appendicular criteria as emerged from within our current study.
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http://dx.doi.org/10.7150/ijms.4997DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3739025PMC
February 2014

Temporary Kirschner wire transfixation versus strapping dressing after second MTP joint realignment surgery: a comparative study with ten-year follow-up.

Foot Ankle Int 2013 Jul 14;34(7):984-9. Epub 2013 Mar 14.

Medical University of Vienna, 1090 Vienna, Austria.

Background: Instability of the second metatarsophalageal (MTP) joint is a common disorder of the forefoot and can be addressed operatively. The objective of this study was to compare a temporary K-wire fixation (tKW) to a postoperative strapping dressing (SD) after realignment surgery of second MTP instability in combination with correction of claw toe deformity.

Methods: Fifty-four consecutive patients with metatarsal index plus or neutral and a collective total of 62 operative interventions were examined at 10 years postoperatively. The operative intervention included dorsal capsulotomy, incision of the extensor hood, and lengthening of the extensor tendon. All operations were carried out at a single institution by orthopedic surgeons experienced in foot surgery. One team preferred fixation with tKW, whereas the other team used only noninvasive SD for postoperative management. The assessment included the American Orthopaedic Foot & Ankle Society (AOFAS) metatarsophalangeal-interphalangeal score as well as the visual analogue scale (VAS) for pain. Kaplan Meier analysis with recurrence of subluxation as the end point was performed, and plain radiographs of the forefoot were investigated.

Results: Survival without recurrence of second MTP subluxation was significantly higher in the tKW group (93%) compared with the SD group (88%) (P < .001). There was no statistical significant difference in pre- to postoperative AOFAS and VAS pain between the 2 groups.

Conclusion: Temporary K-wire fixation had a significantly lower recurrence rate of second MTP subluxation compared with postoperative SD for postoperative alignment management in second MTP instability.

Level Of Evidence: Level III, therapeutic study.
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http://dx.doi.org/10.1177/1071100713478406DOI Listing
July 2013

Treatment of varus deformities of the lower limbs in patients with achondroplasia and hypochondroplasia.

Open Orthop J 2013 8;7:33-9. Epub 2013 Feb 8.

Ludwig Boltzmann Institute of Osteology, at the Hanusch Hospital of WGKK and, AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Vienna, Austria ; Orthopaedic Hospital of Speising, Paediatric Department, Vienna, Austria.

Angular deformities of the lower limbs are a common clinical problem encountered in pediatric orthopaedic practices particularly in patients with osteochondrodysplasias. The varus deformity is more common than the valgus deformity in achondroplasia and hypochondroplasia patients because of the unusual growth of the fibulae than that of the tibiae. We retrospectively reviewed six patients (four patients with achondroplasia and two patients with hypochondroplsia) with relevant limb deformities due to the above-mentioned entities. All patients manifested significant varus deformity of the lower limbs. Detailed phenotypic characterization, radiologic and genetic testing was carried out as baseline diagnostic tool. We described the re-alignment procedures, which have been applied accordingly. Therefore, bilateral multi-level procedures, multi-apical planning and limb lengthening have been successfully applied. While recognition of the underlying syndromic association in patients who are manifesting angular deformities is the baseline for proper orthopaedic management, this paper demonstrates how to evaluate and treat these complex patients.
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http://dx.doi.org/10.2174/1874325001307010033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3580759PMC
March 2013

Validity and reliability of the Paprosky acetabular defect classification.

Clin Orthop Relat Res 2013 Jul 15;471(7):2259-65. Epub 2013 Feb 15.

Orthopaedic & Trauma Service, Department of Orthopaedic & Trauma, Royal Adelaide Hospital, Adelaide, SA, Australia.

Background: The Paprosky acetabular defect classification is widely used but has not been appropriately validated. Reliability of the Paprosky system has not been evaluated in combination with standardized techniques of measurement and scoring.

Questions/purposes: This study evaluated the reliability, teachability, and validity of the Paprosky acetabular defect classification.

Methods: Preoperative radiographs from a random sample of 83 patients undergoing 85 acetabular revisions were classified by four observers, and their classifications were compared with quantitative intraoperative measurements. Teachability of the classification scheme was tested by dividing the four observers into two groups. The observers in Group 1 underwent three teaching sessions; those in Group 2 underwent one session and the influence of teaching on the accuracy of their classifications was ascertained.

Results: Radiographic evaluation showed statistically significant relationships with intraoperative measurements of anterior, medial, and superior acetabular defect sizes. Interobserver reliability improved substantially after teaching and did not improve without it. The weighted kappa coefficient went from 0.56 at Occasion 1 to 0.79 after three teaching sessions in Group 1 observers, and from 0.49 to 0.65 after one teaching session in Group 2 observers.

Conclusions: The Paprosky system is valid and shows good reliability when combined with standardized definitions of radiographic landmarks and a structured analysis.

Level Of Evidence: Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.1007/s11999-013-2844-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676616PMC
July 2013

Fractures in connection with an atypical form of craniodiaphyseal dysplasia: case report of a boy and his mother.

Clinics (Sao Paulo) 2012 Dec;67(12):1505-9

Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, First Medical Department, Ludwig Boltzmann Institute of Osteology, Viena, Austria.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521819PMC
http://dx.doi.org/10.6061/clinics/2012(12)26DOI Listing
December 2012

Altered matrix mineralization in a case of a sclerosing osteosarcoma.

Bone 2013 Apr 2;53(2):409-13. Epub 2013 Jan 2.

Department of Orthopaedic Surgery, Vienna General Hospital, Medical University of Vienna, Vienna, Austria.

Little is known about the tumor matrix mineralization of highly sclerotic osteosarcoma. We used quantitative backscattered electron imaging (qBEI) to determine the Bone mineralization density distribution (BMDD) of a highly sclerosing osteosarcoma of the proximal tibia as well as adjacent normal bone of a 10-year-old girl following chemotherapy according to the EURAMOS-1 protocol. Data were compared to recently published normative reference data for young individuals. Backscattered electron imaging of the tumor region revealed a dense accumulation of mineralized tumor bone matrix (up to 90% of the medullar space). The BMDD was shifted tremendously towards higher matrix mineralization (CaMean +18.5%, CaPeak +22.5%, CaHigh +100 fold) compared to normal bone. Additionally the BMDD became much wider, indicating a higher heterogeneity in mineralization (CaWidth +40%). In contrast to lamellar bone, which mineralizes via a mineralization front, the mineralization of the tumor matrix starts by randomly distributed spots of mineral clusters fusing together to a highly mineralized non-lamellar bone matrix. We also found an altered BMDD of the patient's normal bone when compared with the reference BMDD of young individuals. In conclusion this high radiodensity region of the sclerosing sarcoma is not only due to the high amount of tumor matrix but also to its high mineralization density. Chemotherapy may lead to altered matrix mineralization of normal bone due to suppression of bone turnover. The mechanism of matrix mineralization in a sclerosing osteosarcoma warrants further studies.
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http://dx.doi.org/10.1016/j.bone.2012.12.043DOI Listing
April 2013

Mineralization pattern of vertebral bone material following fragility fracture of the spine.

J Orthop Res 2012 Jul 6;30(7):1089-94. Epub 2012 Jan 6.

Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria.

Little is known whether trabecular bone matrix mineralization is altered at the site of osteoporotic vertebral fractures. Bone mineralization density distribution (BMDD) was assessed in trabecular bone of acute, single-level compression fractures of the spine at various stages of fracture repair using quantitative backscattered electron imaging (qBEI). The grading of the repair stage was performed by histological methods. From 20 patients, who underwent either kyphoplasty (n=18) or vertebroplasty (n=2), a vertebral bone biopsy was taken prior to cement augmentation. Six patients took bisphosphonates (BP) prior to fracture. Three study groups were formed: N1=early-, N2=late-healing and B=BP treatment at late healing stage. In general, all groups had an altered BMDD when compared to historical normative reference data. Mean matrix mineralization (CaMean) was significantly (p<0.001) lower in all groups (N1: -5%, N2: -16%, and B2: -16%). In N2, CaMean was -13.1% (p<0.001) lower than N1. At this stage, deposition of new bone matrix and/or formation of woven bone are seen, which also explains the more heterogeneous matrix mineralization (CaWidth). Moreover, BP treatment (B2) led to a significant reduction in CaWidth (-28.5%, p<0.001), when compared to N2. Bone tissue from vertebrae with acute compression fractures reveals a large variation in matrix mineralization depending on the stage of repair. Bisphosphonate treatment does affect the mineralization pattern of tissue repair. The low mineralization values found in early stage of repair suggest that altered bone material properties may play a role in the occurrence of fragility fractures of the spine.
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http://dx.doi.org/10.1002/jor.22026DOI Listing
July 2012

Histological correlation of 7 T multi-parametric MRI performed in ex-vivo Achilles tendon.

Eur J Radiol 2013 May 15;82(5):740-4. Epub 2011 Dec 15.

Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna Waehringer Guertel 18-20, A-1090, Vienna, Austria.

Introduction: The goal of this in vitro validation study was to investigate the feasibility of biochemical MRI techniques, such as sodium imaging, T₂ mapping, fast imaging with steady state precession (FISP), and reversed FISP (PSIF), as potential markers for collagen, glycosaminoglycan and water content in the Achilles tendon.

Materials And Methods: Five fresh cadaver ankles acquired from a local anatomy department were used in the study. To acquire a sodium signal from the Achilles tendon, a 3D-gradient-echo sequence, optimized for sodium imaging, was used with TE=7.71 ms and TR=17 ms. The T₂ relaxation times were obtained using a multi-echo, spin-echo technique with a repetition time (TR) of 1200 ms and six echo times. A 3D, partially balanced, steady-state gradient echo pulse sequence was used to acquire FISP and PSIF images, with TR/TE=6.96/2.46 ms. MRI parameters were correlated with each other, as well as with histologically assessed glycosaminoglycan and water content in cadaver Achilles tendons.

Results: The highest relevant Pearson correlation coefficient was found between sodium SNR and glycosaminoglycan content (r=0.71, p=0.007). Relatively high correlation was found between the PSIF signal and T2 values (r=0.51, p=0.036), and between the FISP signal and T₂ values (r=0.56, p=0.047). Other correlations were found to be below the moderate level.

Conclusion: This study demonstrated the feasibility of progressive biochemical MRI methods for the imaging of the AT. A GAG-specific, contrast-free method (sodium imaging), as well as collagen- and water-sensitive methods (T₂ mapping, FISP, PSIF), may be used in fast-relaxing tissues, such as tendons, in reasonable scan times.
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http://dx.doi.org/10.1016/j.ejrad.2011.09.022DOI Listing
May 2013

Sodium MR imaging of Achilles tendinopathy at 7 T: preliminary results.

Radiology 2012 Jan 4;262(1):199-205. Epub 2011 Nov 4.

Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.

Purpose: To investigate the feasibility of sodium magnetic resonance (MR) imaging in the diagnosis of Achilles tendinopathy.

Materials And Methods: Institutional review board approval and written informed consent were obtained. Twenty healthy volunteers and eight patients with Achilles tendinopathy were examined by using a 7-T whole-body MR imager with a 15-channel sodium knee coil. The sodium signal-to-noise ratio (SNR) from each region, as well as from the whole Achilles tendon, was compared between patients and healthy control subjects. The changes in SNR were assessed with a two-tailed unpaired t test in three regions of the Achilles tendon: the insertion area, the middle portion, and the muscle-tendon junction. P values less than .05 were considered to indicate a statistically significant difference. To validate a relationship between the sodium SNR and the glycosaminoglycan content in tendon, five cadaver ankles were examined with MR imaging and immunohistologically. The Pearson correlation coefficient between sodium SNR and glycosaminoglycan content was calculated.

Results: Significant differences (P < .05) in the mean sodium SNR of healthy control subjects (mean SNR, 4.9 ± 2.1 [standard deviation]) and patients with chronic Achilles tendinopathy (mean SNR, 9.3 ± 2.3) were observed. Similar results were found at the insertion (mean SNR in control subjects, 6.7 ± 2.3; mean SNR in patients, 12.3 ± 4.5; P < .05) and the midportion (mean SNR in control subjects, 5.1 ± 1.9; mean SNR in patients, 9.4 ± 3.0; P < .05) of the Achilles tendon. At the muscle-tendon junction, the sodium SNR difference between control subjects and patients was small but still bellow the significance level (P = .0137). The increase in sodium SNR was observed in all regions independently of the location of morphologic findings. The Pearson correlation coefficient between sodium SNR and glycosaminoglycan content was 0.71.

Conclusion: Sodium MR imaging may allow detection of the proteoglycan content increase in Achilles tendinopathy and thus identify the biochemical changes in the early stages of tendinopathy.
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http://dx.doi.org/10.1148/radiol.11110897DOI Listing
January 2012

Increased strontium uptake in trabecular bone of ovariectomized calcium-deficient rats treated with strontium ranelate or strontium chloride.

J Synchrotron Radiat 2011 Nov 15;18(Pt 6):835-41. Epub 2011 Sep 15.

Atominstitut, Technische Universitaet Wien, Stadionallee 2, 1020 Vienna, Austria.

Based on clinical trials showing the efficacy to reduce vertebral and non-vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl(2)). Three-month-old ovariectomized rats were treated for 90 days with doses of 25 mg kg(-1) d(-1) and 150 mg kg(-1) d(-1) of SrR or SrCl(2) at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron-radiation-induced micro X-ray fluorescence and by backscattered electron imaging. Principal component analysis and k-means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl(2)-treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment.
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http://dx.doi.org/10.1107/S090904951103038XDOI Listing
November 2011

The diagnosis and management of patients with idiopathic osteolysis.

Pediatr Rheumatol Online J 2011 Oct 13;9:31. Epub 2011 Oct 13.

Ludwig-Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, First Medical Department, Hanusch Hospital, Vienna, Austria.

Idiopathic osteolysis or disappearing bone disease is a condition characterized by the spontaneous onset of rapid destruction and resorption of a single bone or multiple bones. Disappearing bone disorder is a disease of several diagnostic types. We are presenting three patients with osteolysis who have different underlying pathological features. Detailed phenotypic assessment, radiologic and CT scanning, and histological and genetic testing were the baseline diagnostic tools utilized for diagnosis of each osteolysis syndrome. The first patient was found to have Gorham-Stout syndrome (non-heritable). The complete destruction of pelvic bones associated with aggressive upward extension to adjacent bones (vertebral column and skull base) was notable and skeletal angiomatosis was detected. The second patient showed severe and aggressive non-hereditary multicentric osteolysis with bilateral destruction of the hip bones and the tarsal bones as well as a congenital unilateral solitary kidney and nephropathy. The third patient was phenotypically and genotypically compatible with Winchester syndrome resulting in multicentric osteolysis (autosomal recessive). Proven mutation of the (MMP2-Gen) was detected in this third patient that was associated with 3MCC deficiency (3-Methylcrontonyl CoA Carboxylase deficiency). The correct diagnoses in our 3 patients required the exclusion of malignant osteoclastic tumours, inflammatory disorders of bone, vascular disease, and neurogenic arthropathies using history, physical exam, and appropriate testing and imaging. This review demonstrates how to evaluate and treat these complex and difficult patients. Lastly, we described the various management procedures and treatments utilized for these patients.
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http://dx.doi.org/10.1186/1546-0096-9-31DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3203843PMC
October 2011

No effect of short-term hypertension on bone matrix mineralization in a surgical animal model in immature rabbits.

Clin Exp Hypertens 2012 3;34(2):107-12. Epub 2011 Oct 3.

Ludwig Boltzmann Institute of Osteology, Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria.

Epidemiological studies show that arterial hypertension is associated with bone loss and an increased risk of fractures. Bone material properties are essential for bone strength. However, little is known about the effects of hypertension on bone matrix mineralization. Genetic animal models of hypertension are not ideal for studying bone matrix properties since these mutations may affect mineralization per se. The purpose of this study was to evaluate the effects of short-term hypertension on bone mineral density distribution (BMDD) using quantitative backscattered electron imaging in the proximal humerus in an established surgical model of pressure-overload cardiac hypertrophy in immature rabbits. Banding of the descending aorta was performed in 10-day-old rabbits (n = 4). Systolic blood pressure was elevated at all timepoints in the upper extremity but reached statistical significance at 5 and 6 weeks of age (+30.1% and +25.1 mm Hg; P < 0.05 each, respectively). Diastolic blood pressure was not affected. The left proximal humerus was harvested at 6 weeks of age, which is the maximum time in this animal model. Four non-operated, matched animals served as controls. Bone mineral density distribution parameters were determined in the epiphyseal and metaphyseal regions of the proximal humerus. The bone mineral density distribution parameters which describe the degree and heterogeneity of mineralization as well as the amount of low mineralized matrix showed no significant differences. Moreover no difference in bone length was found. Our study indicates that short-term elevation of blood pressure has no effects on bone matrix mineralization in this surgical model of pressure-overload cardiac hypertrophy in immature rabbits.
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http://dx.doi.org/10.3109/10641963.2011.601382DOI Listing
August 2012

The aetiology behind torticollis and variable spine defects in patients with Müllerian duct/renal aplasia-cervicothoracic somite dysplasia syndrome: 3D CT scan analysis.

Eur Spine J 2011 Oct 8;20(10):1720-7. Epub 2011 May 8.

4th Medical Department, Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK, AUVA Trauma Centre Meidling, Hanusch Hospital, Heinrich Collin Str. 30, 1140 Vienna, Austria.

The aim of the article is fourfold; firstly, to detect the aetiology of torticollis in patients with Müllerian duct/renal aplasia-cervicothoracic somite dysplasia syndrome; secondly, spine pathology in Müllerian duct/renal aplasia-cervicothoracic somite dysplasia syndrome varies considerably from one patient to another and there are remarkable differences in severity and localization; thirdly, mismanagement of congenital spine pathology is a frequent cause of morbid/fatal outcome; and fourthly, the application of prophylactic surgical treatment to balance the growth of the spine at an early stage is mandatory. Reformatted CT scans helped in exploring the craniocervical and the entire spine in these patients. The reason behind torticollis ranged between aplasia of the posterior arch of the atlas, assimilation of the atlas and extensive fusion of the lower cervical vertebrae (bilateral failure of segmentation) in four patients; in one patient, in addition to the hypoplastic posterior arch of the atlas, we observed ossification of the anterior and the posterior longitudinal spinal ligaments giving rise to a block vertebrae-like suggestive of early senile ankylosing vertebral hyperostosis (Forestier disease). Scoliosis at different spine levels was attributable to variable spine defects. Pelvic ultrasound showed the classical renal agenesis in four patients; whereas in one patient, the MRI showed pelvic cake kidney (renal fused ectopia) associated with ovarian, uterine and vaginal abnormalities. This is the first exploratory study on the craniocervical and the entire spine in a group of patients with MURCS association.
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http://dx.doi.org/10.1007/s00586-011-1835-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3175860PMC
October 2011