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Title:UPORABA DINAMIČNE MAGNETNORESONANČNE PREISKAVE V SLEDENJU VRAŠČANJA REKONSTRUIRANE KOLENSKE SPREDNJE KRIŽNE VEZI PRI INTRAOPERATIVNI APLIKACIJI RASTNIH FAKTORJEV
Authors:ID Rupreht, Mitja (Author)
ID Jevtič, Vladimir (Mentor) More about this mentor... New window
ID Serša, Igor (Comentor)
Files:.pdf DR_Rupreht_Mitja_2012.pdf (32,58 MB)
MD5: D372A9F45B5DF8AD7226F4AA348C8044
PID: 20.500.12556/dkum/c85728c5-e4e8-4edf-956a-7e5ec8b7fa1f
 
Language:Slovenian
Work type:Dissertation
Organization:MF - Faculty of Medicine
Abstract:Ozadje. Raztrganina sprednje križne vezi (Anterior cruciate ligament, ACL) spada med najpogostejše poškodbe kolena. Po rekonstrukciji je zaradi počasnega vraščanja in ligamentizacije presadka rehabilitacija dolgotrajna. Z namenom pospešiti vraščanje potekajo študije različnih modifikacij rekonstrukcije, v zadnjem desetletju najpogosteje z lokalno apliciranim trombocitnim gelom (TG, Platelet rich plasma gel, PRPG) kot nosilcem različnih rastnih faktorjev (RF). Zaradi etičnih in tehničnih razlogov je histološko ugotavljanje učinkov TG pri človeku praktično nemogoče, predvsem pri vraščanju v oba tunela, zato sledenje poteka neinvazivno z uporabo magnetne resonance (MR). Namen. Prvi namen raziskave je bil ugotoviti uporabnost novejših kvantitativnih MR metod, slikanja z difuzijsko obtežitvijo (Diffusion weighted imaging, DWI) in dinamičnega kontrastnega poudarjenega slikanja (Dynamic contrast enhanced imaging, DCEI), v kvantitativni oceni edema in prekrvljenosti v proksimalnem delu tibialnega tunela, ki je predstavljal interesno področje (Region of interest, ROI). Drugi namen raziskave je bil uporabiti obe kvantitativni MR metodi za oceno morebitnih učinkov intraoperativno lokalno apliciranega TG na edem in prekrvljenost v interesnem področju. Metode. Pri petdesetih bolnikih je bila opravljena artroskopska rekonstrukcija ACL. Testna skupina 25 bolnikov je intraoperativno lokalno prejela TG, medtem ko ga kontrolna skupina preostalih 25 bolnikov ni prejela. Pri vsakem bolniku smo opravili MR preiskavo en, dva in pol ter šest mesecev po posegu. Z DWI in DCEI smo pregledovali proksimalni del tibialnega tunela. Pri vsaki DWI preiskavi smo izračunali vrednost navideznega difuzijskega koeficienta (Apparent diffusion coefficient, ADC) kot merila za mobilnost vodnih molekul. Pri ocenjevanju prekrvljenosti smo pri vsaki DCEI preiskavi izračunali dva parametra: a) gradient obarvanja (G) kot merilo za hitrost obarvanja s paramagnetnim kontrastnim sredstvom (KS), in b) faktor obarvanja (F) kot merilo za jakost obarvanja. Rezultati. Povprečne vrednosti ADC kot tudi G in F so v obdobju sledenja v obeh skupinah med posameznimi kontrolnimi preiskavami značilno upadale. Primerjava skupin kaže, da je bila povprečna vrednost ADC v skupini, ki je prejela TG, en mesec po posegu 1,41 (10-3mm2/s) in značilno nižja kot v kontrolni (1,50 (10-3mm2/s)) skupini (p=0,033). Pri drugi in tretji kontroli razliki v povprečnih vrednostih ADC med skupinama nista bili značilni. Povprečna vrednost G je bila v testni skupini po enem (2,07 %/s) ter dveh in pol (1,64 %/s) mesecih značilno višja kot v kontrolni skupini (1,41 %/s po enem ter 1,15 %/s po dveh in pol mesecih, p=0,019 in p=0,008), pri tretji kontroli pa razlika ni bila značilna. Razlike v izračunanih povprečnih vrednostih F med skupinama pri nobeni kontrolni preiskavi niso bile značilne. Zaključek. Značilno nižja vrednost ADC v proksimalnem tibialnem tunelu skupine, ki je prejela TG, en mesec po rekonstrukciji, kaže na zmanjšanje mobilnosti vodnih molekul v tem področju v primerjavi s kontrolno skupino, kar pripisujemo gostejši celični organizaciji. Značilno višja vrednost G v skupini, ki je prejela TG, en ter dva in pol meseca po posegu, kaže na večjo gostoto krvnih žil v pregledanem področju v primerjavi s kontrolno skupino. Oboje dokazuje zgodnja učinka delovanja rastnih RF in drugih bioaktivnih proteinov v TG kot povečanje števila celic in večjo prekrvljenost v tibialnem tunelu, kar je v skladu s histološkimi opisi učinka RF na živalskih modelih. Kolikor vemo, gre za prvo uporabo DWI ter DCEI MR preiskave v področju ACL. Glede na rezultate naše raziskave ju zato predlagamo kot dodatni kvantitativni metodi ocenjevanja prihodnjih, hitro se razvijajočih modifikacij rekonstrukcije ACL.
Keywords:rekonstrukcija sprednjega križnega ligamenta, vraščanje, trombocitni gel, magnetna resonanca, difuzijsko obteženo MR slikanje, dinamično kontrastno poudarjeno MR slikanje
Place of publishing:Maribor
Publisher:[M. Rupreht]
Year of publishing:2011
PID:20.500.12556/DKUM-22288 New window
UDC:616.75-089.844
COBISS.SI-ID:4203071 New window
NUK URN:URN:SI:UM:DK:TDYSTVRN
Publication date in DKUM:28.03.2012
Views:4450
Downloads:333
Metadata:XML DC-XML DC-RDF
Categories:MF
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Secondary language

Language:English
Title:Quantitative Evaluation of the Tibial Tunnel after Intraoperatively Locally Administered Platelet Rich Plasma Gel during Anterior Cruciate Ligament Reconstruction Using Diffusion Weighted and Dynamic Contrast-Enhanced MRI
Abstract:Background. Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. After reconstruction, slow processes of graft healing and ligamentisation require long rehabilitation period. Many modifications of the reconstruction technique have evolved over the time, among them in last decade the local application of platelet rich plasma gel (PRPG) as the carrier of various growth factors (GF). For ethical and technical reasons, histologic evaluation of ACL graft incorporation as well as of the effects of modifications of ACL reconstruction in humans is impossible. Therefore, their assessment has been performed mostly with magnetic resonance imaging (MRI). Purpose. The first purpose of the study was to assess the feasibility of two new quantitative MRI methods, diffusion weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCEI), in the quantitative assessment of the oedema and vascularity in the proximal tibial tunnel. The second purpose was to assess the effect of locally applied PRPG during ACL reconstruction using two quantitative MRI sequences, DWI and DCEI, for the quantitative measurement of the tibial tunnel oedema and vascularity. Methods. In fifty patients, ACL reconstructions were performed by standard arthroscopic procedure. They were divided in two groups. The patients in the PRPG group locally received an application of PRPG into the tibial and femoral bone tunnels and into the graft itself, whereas patients in the control group did not receive any PRPG. For each patient, MRI examinations were performed one, two and a half and six months after the procedure. The proximal tibial tunnel was examined by DWI and DCEI, which were utilized to calculate apparent diffusion coefficient (ADC) values, which provide information on molecular motion of water, and the contrast enhancement gradient (G) and enhancement factor (F) values, which describe the enhancement rate and static enhancement after intravenously (i.v.) administered paramagnetic contrast medium (CM). Results. Calculated values of ADC, G and F in each group decreased significantly between the control examinations. In comparing the two groups, we find that at one month average ADC in the PRPG (1,41 (10-3mm2/s)) group was significantly lower than in the control (1,50 (10-3mm2/s)) group (p=0.033). At the second and third postoperative controls, the differences in the ADC values were not significant. At one month, average G was significantly higher in the PRPG (2,07 %/s) group than in the control (1,41 %/s) group (p=0.019). Also, at two and a half months, G was also significantly higher in the PRPG (1,64 %/s) group than in the control (1,15 %/s) group (p=0.008). At six months, there was no significant difference in the G between the groups. There were no significant differences in average F between the groups at any control examination. Conclusion. DWI and DCEI MRI proved to be feasible in noninvasive quantitative assessment of the oedema and vascularity in the healing process of ACL graft. In the proximal tibial tunnel, the effect of PRPG, measured with these two quantitative MRI methods, is mostly pronounced at early stages of the healing process. The significant decrease of ADC demonstrates diminished water mobility, presumably due do larger cellularity, in the first postoperative month. The significant increase of the G at one and two and a half months after reconstruction indicates higher vascular density as effect of the locally applied PRPG. Both results are in accordance with early histologic findings of enhanced fibrosis and angiogenesis as effects of intraoperatively administered GF in animal models. To our knowledge, this is the first time DWI and DCEI have been demonstrated in the area of ACL. We propose them as additional quantitative MRI modalities in the assessment of new, rapidly evolving modifications of ACL reconstruction technique.
Keywords:anterior cruciate ligament reconstruction, healing, platelet gel, MRI, diffusion-weighted MRI, dynamic contrast-enhanced MRI


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