Nowadays, the encouranged treatment for end-stage ankle osteoarthritis is the total an kle replacement. Deformations triggered by oestoarthritis can lead to a misalignment of articular surfaces that are particularly painful for the patient and that can limit his physical activity. The goal of the total ankle replacement is to re-align the ankle. This alignment is usually measured using the angle between the main tibial axis and the tibial plafond in the frontal and in the sagittal plane. A precise planification of the intervention and the use of patient-specific cutting guides are recommanded to insure a success of the intervention. The QUANTUM prosthesis, commercialized by Conmed since 2021 follows those recommendations. The pre-operative planning can be perfomed using two different types of imaging: a classic CT scan that needs to be correctd with an X-ray to have the leg in astanding position or a Cone Beam, which allows to capture the anatomy of the ankle in a standing position. A few different techniques have been tried out to automatize the measure of clinical parameters and showed no significant differences between the two imaging technique for the pre-operative planning. Both the CT scan and the Cone Beam provide information on the bone mineral den sity of the patient. However, for now, this data is not taken into account. The possible impact of bone mineral density on the outcome on the intervention was studied. The population was composed of 7 patients 3 patients with a prosthetic failure and 4 without. All of the patients showed a significant bone remodelling 4 months after the intervention. However, the re-alignment of the ankle did change the load distribution in the joint and, thus, the repartition of the density in all of the patients. Significant differences have been demonstrated between measures performed with the CB and measures performed with the CT. These measures might come from a lower X-ray penetration of the CB. Another discovery was that when patients wear a cast, the mea sures of bone mineral density are always surestimated. Future prospects might include the design of a cast in a material that does not absorb the X-rays.
Oggi, il trattamento incoraggiato per l’osteoartrite della caviglia in fase terminale è la sos tituzione totale della caviglia. Le deformazioni innescate dall’osteoartrite possono portare a undisallineamento delle superfici articolari particolarmente doloroso per il paziente e che può limitare la sua attività fisica. L’obiettivo della protesi totale di caviglia è quello di ri allineare la caviglia. Questo allineamento viene solitamente misurato utilizzando l’angolo tra l’asse tibiale principale e il piatto tibiale sul piano frontale e sagittale. Per garantire il successo dell’intervento, si raccomanda una precisa pianificazione dell’intervento e l’uso di guide di taglio specifiche per il paziente. La protesi QUANTUM, commercializzata da Conmed dal 2021, segue queste raccomandazioni. La pianificazione pre-operatoria può essere eseguita utilizzando due diversi tipi di immagini: una TAC classica che deve essere corretta con una radiografia per avere la gamba in posizione eretta o una Cone Beam, che permette di catturare l’anatomia della caviglia in posizione eretta. Sono state sperimen tate alcune tecniche diverse per automatizzare la misurazione dei parametri clinici e non hanno mostrato differenze significative tra le due tecniche di imaging per la pianificazione pre-operatoria. Sia la TC che la Cone Beam forniscono informazioni sulla densità minerale ossea del paziente. Tuttavia, per il momento, questo dato non viene preso in considerazione. È stato studiato il possibile impatto della densità minerale ossea sull’esito dell’intervento. La popolazione era composta da 7 pazienti 3 pazienti con fallimento protesico e 4 senza. Tutti i pazienti hanno mostrato un significativo rimodellamento osseo 4 mesi dopo l’intervento. Tuttavia, il riallineamento della caviglia ha modificato la distribuzione del carico nell’articolazione e, quindi, la ripartizione della densità in tutti i pazienti. Sono state dimostrate differenze significative tra le misure eseguite con la CB e quelle eseguite con la TC. Queste misure potrebbero derivare da una minore penetrazione dei raggi X della CB. Un’altra scoperta è stata che quando i pazienti indossano un gesso, le misure della densità minerale ossea sono sempre stimate con certezza. Le prospettive future potrebbero includere la progettazione di un’ingessatura in un materiale che non assorba i raggi X.
QUANTUM total ankle prosthesis: evaluation of the effect of the bone mineral density and the pre-operative planning on the post-operative follow-up
Sales-Vaninetti, Elise
2023/2024
Abstract
Nowadays, the encouranged treatment for end-stage ankle osteoarthritis is the total an kle replacement. Deformations triggered by oestoarthritis can lead to a misalignment of articular surfaces that are particularly painful for the patient and that can limit his physical activity. The goal of the total ankle replacement is to re-align the ankle. This alignment is usually measured using the angle between the main tibial axis and the tibial plafond in the frontal and in the sagittal plane. A precise planification of the intervention and the use of patient-specific cutting guides are recommanded to insure a success of the intervention. The QUANTUM prosthesis, commercialized by Conmed since 2021 follows those recommendations. The pre-operative planning can be perfomed using two different types of imaging: a classic CT scan that needs to be correctd with an X-ray to have the leg in astanding position or a Cone Beam, which allows to capture the anatomy of the ankle in a standing position. A few different techniques have been tried out to automatize the measure of clinical parameters and showed no significant differences between the two imaging technique for the pre-operative planning. Both the CT scan and the Cone Beam provide information on the bone mineral den sity of the patient. However, for now, this data is not taken into account. The possible impact of bone mineral density on the outcome on the intervention was studied. The population was composed of 7 patients 3 patients with a prosthetic failure and 4 without. All of the patients showed a significant bone remodelling 4 months after the intervention. However, the re-alignment of the ankle did change the load distribution in the joint and, thus, the repartition of the density in all of the patients. Significant differences have been demonstrated between measures performed with the CB and measures performed with the CT. These measures might come from a lower X-ray penetration of the CB. Another discovery was that when patients wear a cast, the mea sures of bone mineral density are always surestimated. Future prospects might include the design of a cast in a material that does not absorb the X-rays.File | Dimensione | Formato | |
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2024_07_Sales_Vaninetti_Executive_Summary.pdf
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2024_07_Sales_Vaninetti_Tesi.pdf
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https://hdl.handle.net/10589/223697