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Wyznaczenie lokalnych poziomów referencyjnych dla kończyny górnej i dolnej na podstawie operacji ortopedycznych u dzieci z użyciem ramienia C

Badziak M., Matera K., Grzelak P.

Inżynier i Fizyk Medyczny

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2018

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Vol. 7, nr 5

323--327

PL

Uzasadnienie. Ważnym aspektem w ochronie radiologicznej jest zapewnienie bezpieczeństwa dzieciom w czasie operacji ortopedycznych z użyciem fluoroskopii. Ze względu na wysoką promieniowrażliwość dzieci, bardzo ważna jest kontrola dawek oraz zapewnienie im odpowiedniej ochrony radiologicznej. Cel. Celem tej pracy było oszacowanie dawki powierzchniowej oraz czasu ekspozycji z fluoroskopii wykonywanych w czasie operacji ortopedycznych dzieci oraz wyznaczenie lokalnych diagnostycznych poziomów referencyjnych na podstawie tych parametrów. Materiał i metody. W badaniu uwzględniono 501 pacjentów (mediana 11 lat), którzy przeszli operacje ortopedyczne z użyciem fluoroskopii. Pomiaru dawek dokonano w czasie zabiegów ortopedycznych celowanych na kończyny dolne i górne z użyciem mobilnego ramienia C (Ziehm-8000) pomiędzy marcem a sierpniem 2017 roku. Dawki zebrano na podstawie wskazań miernika kompatybilnego z aparatem. Wyniki. Średnia dawka powierzchniowa przypadająca na obszar kończyny górnej (73,65%) w badanej populacji wynosi 25,82 ± 58,10 cGycm2, dawka dla obszaru kończyn dolnych (26,35%) jest równa 91,07 ± 217,27 cGycm2. Lokalne poziomy referencyjne dawki w przedziałach wiekowych: 1-5, 5 ≥ 10 oraz 10 ≥ 15 i powyżej 15. roku życia wynoszą odpowiednio: 22,15, 24,76, 40,08, 55,04 cGycm2. Poziomy referencyjne czasów naświetlania w odniesieniu do podanej kolejności przedziałów są następujące: 60,75, 82,75, 124,50, 108,00 s. Wnioski. Wyniki pokazują, iż kończyny dolne otrzymują znacznie wyższe dawki niż kończyny górne w czasie operacji. Wynika to głównie z tego, że kończyny dolne mają większą objętość względem górnych. Otrzymane poziomy referencyjne układają się w tendencji wzrostowej zarówno dla DAP, jak i czasu ekspozycji. Wyjątkiem jest przedział wiekowy > 15 lat, gdzie DRL czasów ekspozycji jest niższy niż u młodszych dzieci. Podsumowanie. Na podstawie pomiaru rzeczywistych dawek powierzchniowych możliwe jest zdefiniowanie lokalnych poziomów referencyjnych. Ich określenie pozwala na kontrolowanie warunków ekspozycji w czasie operacji ortopedycznych. Ma to znaczenie zarówno dla ochrony radiologicznej pacjentów, jak i dla usystematyzowania pracy operatorów fluoroskopii, którzy mogą świadomie dobierać odpowiednie dla wieku pacjenta warunki ekspozycji.

EN

Background. Radiological protection of the patient during fluoroscopy procedures is an important topic due to the wide scope of its use during orthopaedic surgery. Children are especially sensitive to radiation, thus it is important to control dose and ensure them special radiological protection. Objective. The aim of this study was to estimate DAP and exposure time from fluoroscopy during orthopaedic surgical procedures and to establish DRLs for these parameters. Material and methods. We involved 501 paediatric patients (median age 11) who went orthopaedic surgery with targeted fluoroscopy acquisition. The ionizing radiation was assayed using Dose Area Product Meter. This was done during orthopaedic procedures of lower and upper extremities with using mobile C-arm device (Ziehm-8000) performed between March 2017 and August 2017. Results. As the radiation dose depends on the size of the child, the children were assigned to four different age groups: 1-5, 5-10, 10-15 and > 15 years. The mean, median and third-quartile DAP and the exposure time were calculated for each group. The mean DAP for upper extremities (73.65%) was 25.82 58.10 cGcm2 and for lower extremities (26.35%) was 90.40 216.59 cGcm2. The third-quartile values were used to establish the DRLs. For this age selection the DRLs of the DAP were: 22.15, 24.76, 40.08, 55.04 cGcm2 respectively. The third-quartile the time of exposure for above mentioned age selection were as follows: 60.75, 82.75, 124.50, 108.00 s. Conclusions. The dose from fluoroscopy-guided orthopaedic surgery is higher for lower than upper extremities. It’s came from the size of a lower parts, which have larger volume than the upper parts. The DRLs of DAP and exposure time are collected with upward trend to arising age. Only the children group older than 15 years have DRLs of exposure time higher than the age group between 10-15 years. Discussion. Measurement of the dose area product in narrow group of patients allow to assessed dose reference levels. This procedure enable to control the fluoroscopy parameters during the orthopaedic surgeries. It is important both for the radiological protection of patients and to systematize the work of fluoroscopy operators, who can consciously choose age-appropriate patient exposure conditions.

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Drilling resistance : A method to investigate bone quality

Lughmani W. A., Farukh F., Bouazza-Marouf K., Ali H.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 1

55--62

EN

Purpose: Bone drilling is a major part of orthopaedic surgery performed during the internal fixation of fractured bones. At present, information related to drilling force, drilling torque, rate of drill-bit penetration and drill-bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. Methods: This study demonstrates that bone drilling force data if recorded in-vivo, during the repair of bone fractures, can provide information about the quality of the bone. To understand the variability and anisotropic behaviour of cortical bone tissue, specimens cut from three anatomic positions of pig and bovine were investigated at the same drilling speed and feed rate. Results: The experimental results showed that the drilling force does not only vary from one animal bone to another, but also vary within the same bone due to its changing microstructure. Drilling force does not give a direct indication of bone quality; therefore it has been correlated with screw pull-out force to provide a realistic estimation of the bone quality. A significantly high value of correlation (r 2 = 0.93 for pig bones and r 2 = 0.88 for bovine bones) between maximum drilling force and normalised screw pull-out strength was found. Conclusions: The results show that drilling data can be used to indicate bone quality during orthopaedic surgery.

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Methods for designing and fabrication large-size medical models for orthopaedics

Kudasik T., Libura M., Markowska O., Miechowicz S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2015

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Vol. 63, nr 3

623--627

EN

Computed tomography and rapid prototyping techniques can be used to construct and fabricate large size bone models for orthopaedics. Rapid Prototyping technology enables the fabrication of a true-to-scale bone joint model based on 3D virtual models, generated by segmenting patients’ CT images. The model can be used to plan, to simulate, to assist prosthesis implantation for difficult cases of THR (Total Hip Replacements). The main restriction of implementing such models into medical practice is high cost of their production. Physical models of pelvic bones, were constructed on the basis of data collected during standard CT examinations. A method of development of a large-size model while fulfilling the requirement for reducing the price of model fabrication in the article was presented. The method can be used for fabrication the models with 3DP technique. This paper also discusses the issue of production costs when utilizing other RP techniques as well as their usefulness in practice.

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Modelling and optimization of temperature in orthopaedic drilling : An in vitro study

Pandey R. K., Panda S. S.

Acta of Bioengineering and Biomechanics

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2014

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Vol. 16, no. 1

107--116

EN

This present investigation uses the Taguchi and response surface methodology (RSM) for modelling and optimization of the temperature produced during bone drilling. The drilling of bone is a common procedure in orthopaedic surgery to produce hole for screw insertion to fixate the fracture devices and implants. A major problem which is encountered during such a procedure is the increase in temperature of the bone due to the plastic deformation of chips and the friction between the bone and the drill. The increase in temperature can result in thermal osteonecrosis which may delay healing or reduce the stability and strength of the fixation. The drilling experiments are conducted on poly-methyl-meth-acrylate (PMMA) (as a substitute for bone) using Taguchi’s L27 experimental design technique. The cutting parameters used are drill diameter, feed rate and cutting speed. The optimum cutting parameters for minimum temperature are determined by using S/N ratios and the effect of individual cutting parameters on temperature produced is evaluated using analysis of variance (ANOVA). A second-order model is established between the drilling parameters and temperature using RSM. The experimental results show that the drill diameter is the most significant drilling parameter affecting the temperature during drilling followed by cutting speed and feed, respectively. The values predicted and the values obtained from experiment are fairly close, which indicates that the developed RSM model can be effectively used to predict the temperature in orthopaedic drilling.