Multifocal Osteonecrosis Glucocorticoid Induced

The present study describes a 29 years old patient diagnosed with aseptic osteonecrosis with multiple localization occurred after a corticoid treatment for chronic toxic hepatitis. The clinical and para-clinical examinations determined the diagnosis of Wilson disease and avascular necrosis with multiple localizations. The evolution of the disease was favourable following the surgical treatment consisting of bilateral total hip arthroplasty with cementless prosthesis, hemi-arthroplasty of the left shoulder with cementless prosthesis, orthotopic hepatic transplantation with an entire liver from donor in cerebral death and immunosuppressive, anticoagulant, antiretroviral and gastro-protective treatment. There is an increase of the number of patients undergoing a glucocorticoids treatment for several months, years or lifelong periods. This type of treatment increases the risk of osteonecrosis depending on the dosage and the duration of the treatment.

Immediate Changes of Bone Density Caused by the Implantation of a Femoral Stem - A Dexa Study

Considerable immediate periprosthetic bone density changes after implantation of femoral stems have been observed comparing DEXA measurements taken pre- and post-operatively. This is important in relation to the interpretation of DEXA studies. We analysed these density changes under standardised experimental conditions. Five human femora were implanted with a custom made femoral stem and ten femora with a standard cementless prosthesis. Densitometry was performed at various stages of implantation. Following rasping only slight density changes were noted (–2.7% to +0.7%). Comparing post-implantation and pre-operative measurements, all custom made stems with a proximal press-fit demonstrated clear increases in proximal periprosthetic bone density of +11% and +14%. In contrast, the standard prosthesis with a distal press-fit showed a loss of –5% and –2% in the proximal zones. Measurements following removal of the implants demonstrated hardly any density changes (0% to –4%) compared to the pre-operative measurements. We concluded that compacting of trabecular bone or bone loss due to rasping are not the main causes of density changes. Substantial measuring errors exist. For examination of periprosthetic bone density changes, pre-operative initial measurements should not be used as a baseline for comparison. Studies should commence with an immediate postoperative measurement.

Experimental In-Vitro Method to Measure the Migration of Cementless Prosthesis

In total hip arthroplasty, adequate initial fixation of prosthesis to host bone represents great challenge to its success and satisfactory performance.

A Device to Test the Primary Stability in Cementless Hip Arthroplasty Through Mechanical Vibrations

Primary stability of cementless prostheses is critical for the long term outcome of the operation. Cementless implants are mechanically stabilized during surgery through a press-fitting procedure. To achieve a good initial stability, it is important that the surgeon performs an optimal press-fitting, avoiding both problems of stem loosening, and micro-cracking of the host bone. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of the vibration analysis. This technique was used in the presented study, which was aimed to design and test a prototype device able to evaluate the primary stability of a cementless prosthesis, at the femoral level. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype was developed. It is mainly composed by a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on a composite femur implanted with a conventional stem. The results showed that the input signal is repeatable and the output can be accurately recorded. The parameters that seem to be more sensitive to stability are the resonance frequency and the amplitude at the resonance frequency.

Pirminis mišraus ir mechaninio tvirtinimo klubo sąnario endoprotezavimas. Vėlyvieji 5–10 metų rezultatai

Jaunius Kurtinaitis, Narūnas Porvaneckas, Manvylius Kocius, Rimvaldas BrogaVilniaus universiteto Ortopedijos-traumatologijos ir plastinės chirurgijos klinikaVilniaus greitosios pagalbos universitetinė ligoninėŠiltnamių g. 29, LT-2043 Vilnius.El paštas: [email protected] Įvadas / tikslas Dažniausia endoprotezuoto klubo sąnario problema – gūžduobinio komponento intarpo susidėvėjimas arba jo išklibimas. Vieni autoriai pripažįsta cementinio, kiti – mechaninio tvirtinimo metodiką. Abiem atvejais vėlyvieji rezultatai yra panašūs. Kiekviena metodika tam tikru endoprotezuoto sąnario laikotarpiu išryškina jai būdingas problemas. Mūsų darbo tikslas – įvertinti vėlyvuosius mišraus ir mechaninio tvirtinimo klubo sąnario pirminio endoprotezavimo rezultatus po operacijos praėjus 5–10 metų. Ligoniai ir tyrimo metodai 1993–1998 metais VGPUL Ortopedijos, traumatologijos ir plastinės chirurgijos klinikoje buvo operuoti 36 ligoniai, kuriems buvo atliktos 39 pirminės klubo sąnario endoprotezavimo operacijos naudojant Bi-Metric mechaninio ir mišraus tvirtinimo endoprotezus (EP). Į tyrimą įtraukti 27 ligoniai (29 endoprotezai – 18 mechaninio ir 11 mišraus tvirtinimo), 2002–2003 metais atvykę pasitikrinti. Vidutinis pacientų su mechaninio tvirtinimo protezais stebėjimo laikas (mediana) siekė 7 metus, o su mišraus tvirtinimo – 5 metus. Visiems atvykusiems pacientams buvo atliktos ir įvertintos priekinės abiejų klubo sąnarių rentgenogramos, nustatyta klubo sąnario funkcija pagal Harris Hip Score skalę. Rezultatai 2002–2003 m. ištirta 29 (80%) iš 36 ligonių, operuotų 1993–1998 m. Rentgenologinių tyrimų rezultatai parodė, kad aplink mechaninio tvirtinimo komponentus linijinės demarkacijos nėra. Visi komponentai buvo stabilūs. Kaulas įaugo į mechaninio tvirtinimo komponentus 100% atvejų. Įvertintos osteolizinio proceso aplink gūžduobinį ir šlaunikaulinį komponentus ypatybės, polietileninio intarpo susidėvėjimo prognozės veiksniai atsižvelgiant į endoprotezo tipą, ektopinė osifikacijos įtaka vėlyviesiems klubo sąnario funkciniams rezultatams. Išvados Įvertinti pagal HHS skalę mechaninio ar mišraus tvirtinimo endoprotezavimo rezultatai po 5–10 metų yra geri ir labai geri. Lyginant rentgenologinius pokyčius aplink gūžduobinį ir šlaunikaulinį komponentus matyti, kad pokyčiai aplink mechaninio ir cementinio tvirtinimo šlaunikaulinius komponentus yra gerokai mažesni negu aplink gūžduobinius. Statistiškai patikimo skirtumo tarp polietileno intarpo susidėvėjimo ir panaudoto endoprotezo tipo nebuvo. Gūžduobinio ir šlaunikaulinio komponentų osteoliziniai procesai yra besimptomiai. Šie procesai ir 76% atvejų nustatyta ektopinė osifikacija neturi įtakos geriems ir labai geriems vėlyviesiems operuoto klubo sąnario funkciniams rezultatams. Prasminiai žodžiai: pirminis klubo sąnario endoprotezavimas, mechaninio tvirtinimo endoprotezai, mišraus tvirtinimo endoprotezai. Primary hybrid and cementless total hip arthroplasty. 5 to 10 year follow-up results Jaunius Kurtinaitis, Narūnas Porvaneckas, Manvylius Kocius, Rimvaldas Broga Background / objective The major issue of hip arthroplasty is the wearout or loosening of the acetabular component. Some authors prefer cemented and others cementless hip arthroplasty. In both cases the outcome is similiar. Each method in different periods has its own problems. The aim of the study was to evaluate the late outcome of primary cementless and hybrid total hip replacement 5–10 years after operation. Patients and methods There were 36 patients operated on and 39 operations of primary total hip arthroplasty performed using Bi-Metric hybrid and cementless endoprostheses in 1993–1998. The study included 27 patients (29 endoprostheses) who responded to invitation in 2002–2003. Anteroposterior radiographs of the hip joints were performed for the patients and the functional outcome was evaluated using the Harris Hip score scale. Results During 2002–2003 investigation was carried out on 29 (74%) of 36 hip arthroplasties performed in 1993–1998. Analysis of the data showed no radiolucency signs around the cementless fixation components. All of the components were stable. Bone ingrowth into the cementless prosthesis components was observed in 100% of cases. The osteolysis zones around the acetabular and femoral components were related to the wearout of polythene insertion, but it was asymptomatic. There was no reliable difference between polythene insertion wearout and the type of prosthesis. Ectopic ossification was observed in 76% of cases. Conclusions The study based on HHS score revealed good and very good results 5–10 years after operation. They were comparable with the findings in similar studies. Rentgenological features indicated that there were less alterations around the femoral component compared to the acetabular. Osteolysis around the femoral and acetabular components was asymptomatic and ectopic ossification found in 76% of cases did not interfere with the good functional results. Keywords: primary total hip arthroplasty, cementless prostheses, hybrid prostheses