Introduction: A prosthesis can be used to regain function after an amputation of the lower limbs. Conventionally, the prosthesis is connected to the stump using a tight fitting socket. The socket often leads to sweating, skin problems or discomfort while sitting. A new way of prosthetic attachment is by osseointegration. During osseointegration surgery a titanium implant is fixed to the remainder of the femur. The prosthesis can be attached to the extra- corporeal part of the implant called the abutment. In this way, socket related problems can be avoided. Qualitative analyses have reported improved walking ability, prosthetic use and a higher prosthesis related quality of life in patients using an osseointegrated prosthesis, but not much is known yet on quantitative improvements in gait measured in a clinical setting. Therefore this study mainly aims to compose and execute a measurement protocol for clin- ical quantitative gait analysis of unilateral transfemoral amputees using an osseointegrated prostheses. Furthermore, a biomechanical model will be created using OpenSim and will be validated using the data recorded using the clinical measurements.
Method: A measurement protocol for quantative gait analysis in a clinical setting was cre- ated and carried out by measuring one participant using an osseointegrated prosthesis. The participant walked at self selected walking speed across a runway with force plates built in and walked on the floor next to the runway with equal conditions around. The protocol also included measurements for stability and direction of attention during gait trials. A biome- chanical model of a unilateral transfemoral amputee with an osseointegrated prosthesis was developed using OpenSim. Bones and muscles of one leg were replaced by prosthetic ge- ometry and settings were altered. The model was used to analyse kinematics and kinetics. Results: Spatiotemporal differences were found between the floor and runway condition. Kinematic comparison showed significantly different knee flexion for the intact leg for a small phase in the gait cycle. Despite the spatiotemporal differences were significant, these were mostly small. Together with the lack of kinematic differences, the difference between the two was not considered clinically relevant and only the runway condition was included in the results section. Kinematic and kinetic results were plotted against control values mea- sured with healthy controls. Compared to these controls the prosthetic side showed a larger hip extension peak, no ankle plantairflexion peak, a larger hip flexion moment, absence of a characteristic knee flexion moment and a lower ankle plantairflexion moment. For the intact side the most noticeable differences were a knee flexion and ankle plantairflexion peak later in the gait cycle, lower hip extension moment and a higher knee flexion moment. Further- more, prosthetic side Margin of Stability was higher, around 60% of the bodyweight was carried by the intact leg during standing up from and sitting down on a chair and the direc- tion of attention was more focused downwards during the floor condition measurement. Conclusion: The aim of that the development of a measurement protocol including a biome- chanical model to measure and analyse the gait of a transfemoral amputee using an os- seointegrated prosthesis is achieved. The results from several analyses were compareable to results found in literature, which served as a validation for the model developed in this study.