Développement de marqueurs mécaniques pour la planification chirurgicale : étude du pivot du genou

Abstract

Knee osteoarthrosis is a common and disabling pathology. It can concern young patients. Symptoms are mainly pain as well as reduced knee mobility and stability. The only known treatment for this pathology is replacement of the articulation by an implant. Knee functionalities are noticeable during motion. It seems relevant to look at knee kinematics using mechanical markers to evaluate knee kinematics. Knee pivot point is one of these markers that can be used to assess the joint motion. It can be used to show the evolution of knee kinematics during osteoarthrosis development or the impact of knee replacement. In the literature, several methods are proposed to calculate knee pivot point, using different motion capture techniques. Nevertheless, their uses are restricted to research protocols. The goal of this thesis is, in a first time, to present another method to calculate knee pivot. This method has to be appropriate to a clinical use. In a second time, this method is applied to a group of patients who underwent unicompartimental knee arthroplasty. The aim of this study is to evaluate the impact of this surgery on knee pivot point. The purposed methods extends works done by Scott A. Banks & Hodge, (2004). Knee pivot point is calculated in tibial transverse plan. It is defined as the intersection of consecutive projected transepicondylar axes in this plan. This methods classes pivots into four pivot motion patterns. Pivots can be centrals, medials or laterals. In some case, anteroposterior translation is way bigger than rotation. These cases are classified as no pivot motion pattern. This method uses data acquired during kneekinesiography, a clinical exam. This method is then applied to a group of patients suffering from knee osteoarthrosis and who underwent unicompartimental arthroplasty. Knee pivot point is calculated before and after surgery. Gait cycle is split between two phases, stance and swing. During stance phase, 55% of patients presented the same pivot motion pattern before and after arthroplasty. This proportion is 68% during swing phase. Most of patients presents no pivot or a central pivot motion pattern. During swing phase particularly, more than 75% of patients presents no pivot. This result brings to mind that this translation is linked with high flexion degrees. Studying stance phase seems to be more pertinent to notice difference between patients. This thesis presents a clinical designed method to calculate and classify knee pivot point. It can be used to follow osteoarthrosis development or to help at surgical planning. Results of this method on a patient group are also exposed. They can be used to evaluate impact of unicompartimental arthroplasty on knee pivot point.

Date	13 Jun 2023
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Nicola Hagemeister (Supervisor) & Laurence Chèze (Co-supervisor)