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Stress analysis of total hip arthroplasty with a fully hydroxyapatite-coated stem: comparing thermoelastic stress analysis and CT-based finite element analysis

Watanabe Ryunosuke, Mishima Hajime, Takehashi Hironori, Wada Hiroshi, Totsuka Sho, Nishino Tomofumi, Yamazaki Masashi, Hyodo Koji

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 2

47--54

EN

The aim of this study was to evaluate the stress distribution in a synthetic femur that was implanted with a fully hydroxyapatite- coated stem using thermoelastic stress and finite element analyses, and to clarify the differences in the stress distributions between these two methods. Methods: Thermoelastic stress analysis is a stress-analysis technique that employs the thermoelastic effect. Sinusoidal vertical loads were applied to the head of the stem placed on the synthetic femur, and surface stress distribution images were acquired using an infrared stress measurement system. The finite element model for the synthetic femur and stem were set up similarly to the thermoelastic stress analysis experiment, and vertical load was applied to the head of the stem. Surface stress distribution and stress values obtained via these two methods were compared. Results: Thermoelastic stress analysis showed that compressive and tensile stresses were distributed from the proximal femur to the diaphysis, not only on the medial and lateral surfaces, but also on the anterior and posterior surfaces. However, finite element analysis showed that compressive stress was not distributed on the anterior and posterior surfaces of the femoral intertrochanter. The stress values of thermoelastic stress analysis tended to be higher in the proximal femur than that obtained via the finite element analysis. Conclusions: The surface stress distribution obtained by these two methods were different specifically in the proximal femur. Our results imply that thermoelastic stress analysis has a better potential than finite element analysis to show the surface stress distribution that reflects the stem design.

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Prototyp urządzenia wspomagającego śródoperacyjną kontrolę długości kończyn dolnych podczas zabiegu endoprotezoplastyki stawu biodrowego

Poryzała P., Kobierska A., Podsędkowski L., Rakowski P.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 8

127--130

PL

W artykule przedstawiono prototyp urządzenia umożliwiającego śródoperacyjny pomiar zmiany długości kończyny podczas zabiegów endoprotezoplastyki stawu biodrowego. Zaproponowany system to miniaturowe, siedmio-członowe ramię pomiarowe, mierzące przemieszczenie kości udowej względem kości miednicznej pacjenta. Pomiar odbywa się dwuetapowo. W pierwszym kroku, przed obcięciem głowy kości udowej i wstawieniem implantu, rejestrowana jest geometria wzorcowa. W drugim kroku, po wstawieniu implantu, system umożliwia wielokrotne pomiary jego geometrii – każdorazowo podając względną zmianę parametrów wydłużenia i odsunięcia (odniesioną do zapisanej w pierwszym kroku wartości wzorcowej). Na podstawie otrzymanych wyników chirurg-ortopeda może dobierać wielkości główki, kąt i długości szyjki trzpienia endoprotezy. Pomiary wykonane na przygotowanym stanowisku badawczym potwierdzają precyzję pomiaru zaprojektowanego urządzenia na poziomie jednego milimetra oraz ich wysoką powtarzalność.

EN

The article presents a prototype of a device for intraoperative measurements of limb length changes during total hip arthroplasty (THA). The proposed system is a miniature, seven-element measuring arm designed for measurements of relative femur – plevic bone displacements. Measurements take place in two stages. In the first step, before the removal of the femoral head and insertion of the implant, original geometry of the joint is recorded and stored as a reference value. In the second step, after insertion of the implant, the system allows for multiple measurements of its geometry. With each measurement, a relative change in elongation and femoral offset is given. Values of both parameters are used by a surgeon to optimize the size of femoral head and the angle and length of the neck of femoral stem. Tests and measurements conducted on a hip joint model confirm the milimiter accuracy of the proposed device and prove high repeatability of the results.

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Dynamic parameters of three-point crutch gait in female patients after total hip arthroplasty

Murawa M., Dworak L. B., Kabaciński J., Syczewska M., Rzepnicka A.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 2

131--135

EN

Purpose: Patient recovery after a surgical procedure depends, among other factors, on the amount of the body weight with which patient loads lower limb. Research studies report different results of the degree of body weight with which lower limb is loaded during three-point crutch gait. The aim of this study was to evaluate the level of the ground reaction forces (GRF) during crutch gait used by patients after total hip arthroplasty (THA) in the first week after discharge from the orthopaedic units. Methods: Ten female patients diagnosed with primary unilateral coxarthrosis participated in a single measurement session. In order to record kinematic and dynamic variables of this gait pattern motion analysis system was used together with two force plates. The static test of body weight distribution between lower limbs was performed on a dual-top stabilometric plate. Results: The average peak values of loading on the operated (O) limb during mid stance and terminal stance of three-point crutch gait were 64.6% and 64.3% of body weight (BW), respectively, whereas in the case of the nonoperated (NO) limb 103.5%BW and 108.8%BW, respectively. The maximum loads on the crutches were significantly higher (by 9%BW) on the NO side as compared to the O side ( p < 0.05). During the static test, average values of body weight distribution on the O and NO limb were 36%BW and 64%BW, respectively. Conclusions: The patients showed surprisingly similar level of loading on the O limb. The weight bearing on the O limb was lower during static trial than during three-point crutch gait.

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Historia endoprotez stawu biodrowego do roku 1962

Ciećkiewicz A., Cwanek J.

Problemy Nauk Stosowanych

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2014

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T. 2

131--142

PL

Wstęp i cel: Niezadowalające wyniki leczenia zmian zwyrodnieniowych stawu biodrowego metodami nieoperacyjnymi (zachowawczymi) w XIX wieku, zmusiły lekarzy do poszukiwania chirurgicznych metod leczenia choroby. Przyczyniło się to do skonstruowania endoprotez stawu biodrowego. Materiał i metody: W oparciu o dane z piśmiennictwa, w pracy przedstawiono rozwój endoprotezoplastyki stawu biodrowego od końca XIX wieku do 1962 roku, kiedy Charnley wszczepił pierwszy „niskotarciowy” sztuczny staw biodrowy. Mimo wprowadzenia licznych zmian konstrukcyjnych po 1962 r., zasady budowy endoprotez biodra nie zmieniły się. Wyniki: Wszczepienie w 1962 r. pierwszej „niskotarciowej” endoprotezy, pozwoliło na powszechne stosowanie endoprotezoplastyki biodra w procesie leczenia zmian zwyrodnieniowych stawu biodrowego. Wniosek: Pomimo wielu wad endoprotezoplastyki biodra, jest to najskuteczniejsza metoda leczenia zaawansowanych artroz biodra.

EN

Introduction and aim: Unsatisfactory results of treatment of degenerative changes in the hip joint methods unresectable (conservative) in the nineteenth century, doctors forced to seek surgical treatments for the disease. This contributed to the construction of hip replacements. Material and methods: Based on data from the literature, the paper presents the development of hip replacement since the late nineteenth century until 1962, when implanted Charnley first “lowfrictional” artificial hip joint. Despite the introduction of numerous design changes to the 1962 rules for the construction of replacement hip has not changed. Results: Implantation in 1962, the first “low-friction” prosthesis, led to widespread use of hip arthroplasty in the treatment of degenerative changes in the hip joint. Conclusion: Despite the many flaws hip arthroplasty is the most effective method of treatment of advanced arthritis hip.

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Baza danych parametrów kątowych mocowania endoprotezy stawu biodrowego typu metal-metal

Mróz A., Gierzyńska-Dolna M., Woźniak W., Theuss M., Moskalik T.

Hutnik, Wiadomości Hutnicze

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2014

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Vol. 81, nr 1

44--49

PL

Na podstawie przeprowadzonych testów tarciowo-zużyciowych endoprotez stawu biodrowego, typu metal-metal, z zastosowaniem symulatora ruchu, została opracowana relacyjna baza danych. W zależności od ustawienia wzajemnego komponentów endoprotezy (głowy i panewki) wyznaczone zostały opory tarcia i zużycie. Uzyskane wyniki badań pozwoliły określić względnie najbardziej korzystną kombinację wartości kąta antetorsji głowy i kąta antewersji panewki. Badaniom poddane zostały endoprotezy firmy Zimmer Inc stosowane w praktyce klinicznej, których powierzchnie trące wykonane były ze stopu Co28Cr6Mo (Metasul). Dla wizualizacji zgromadzonych informacji opracowany został serwis webowy, powiązany w sposób bezpośredni z bazą danych. Narzędzie pozwala zasymulować wartości wielkości opisujących opory tarcia i oszacować zużycie na podstawie wprowadzonych do wyszukiwarki wartości kątów wyrażonych w stopniach. Dzięki temu unikatowemu serwisowi, lekarz ortopeda, już na etapie postępowania przedoperacyjnego będzie mógł wprowadzić korekty w proponowanym przez siebie ustawieniu elementów układu „głowa-panewka”. Korekta ustawienia powinna być dokonana z uwzględnieniem budowy anatomicznej pacjenta.

EN

A referential database was prepared based on the friction and wear tests made on a metal-on-metal endoprosthesis with the use of a movement simulator. Depending on the mutual position of the endoprosthesis components friction resistances and wear of the components has been determined. The obtained test results allowed a relative determination of the most favorable combination of the femoral component (head) antetorsion angle and cup anteversion angle. The tests covered endoprostheses manufactured by Zimmer Inc. with friction surfaces made of Co28Cr6Mo alloy (Metasul). For the purposes of visualization of the collected data, a web service was developed as connected directly to the database. The tool allows an estimation of the values describing friction and wear based on angle data entered into a web browser. Owing to the unique database, an orthopedist will be able to make adjustments in his suggested position of the “head-cup” elements at the very stage of pre-operative procedures. The position adjustment should be made in consideration of the patient’s anatomy.

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Influence of cementless cup surface on stability and bone fixation 2 years after total hip arthroplasty

Urbański W., Krawczyk A., Dragan Sz.Ł., Kulej M., Dragan Sz.F.

Acta of Bioengineering and Biomechanics

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2012

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Vol. 14, no. 2

27-35

EN

Loss of fixation between bone and implant surface is one of the main treatment problems in total hip arthroplasty. It might lead to implant instability, bone loss and treatment failure resulting in revision surgery. Surface modification is a method for improving bone response to implant and increasing implant osseointegration. However, the currently applied modifications such as hydroxyapatite coatings do not meet expectation and do not provide good clinical result. The object of the study was to evaluate the influence of acetabular cup surface modification on fixation and bone remodelling in total hip arthroplasty. Clinical and radiological outcomes were evaluated in patients two years after cementless total hip replacement. Two groups were compared: patients with acetabular component with uncoated titanium surface and patients with hydroxyapatite-coated acetabular surface. Hips X-rays were analysed for early signs of losing stability of acetabular cups. Two years after surgery the analysis of X-rays did not reveal any statistical differences in stability, migration of acetabular components of endoprosthesis between both groups. No differences were also observed in bone remodelling around implants. Particularly high percentage of cups, i.e. 17.64%, were classified into the group with high risk of early implant loosening, i.e., the group with HA coatings. Hydroxyapatite coatings on titanium cementless acetabular cups implanted by press-fit technique have no influence on their stability, bone-implant fixation and the remodelling of bone surrounding an implant two years after surgery.