LOOP - Longitudinal study on the mobility of transfemoral amputees after osseointegrated prosthesis treatment.

• Applicant: Dr. Bastian Welke
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery
• Term: since 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 345584830

In Germany, approximately 25,000 major amputations are performed annually. The cumulative case rate of transfemoral and hip amputations is 19%. A transfemoral amputation is often unable to support loads at the distal end of the stump, which can lead to pressure ulcers and skin irritation. In addition, short stumps are usually difficult to care for. This often leads to limitations in mobility and the patient's quality of life. With the transcutaneous osseointegrated prosthesis systems (TOPS), an alternative to the conventional socket technique has been available for almost thirty years now. TOPS allows the exo prosthesis to be anchored directly in the remaining femur by means of an implant. The main advantage of TOPS is the improvement of mobility and quality of life of patients with transfemoral amputation. In the previous project, the actual condition of transfemoral amputees fitted with a stem or TOPS was compared. No significant difference was found in most of the parameters studied. However, large individual differences in mobility and satisfaction were found within the two groups. The individual progress that the fitting with TOPS can mean for the individual patient was not investigated. The aim of the present follow-up proposal is precisely to determine the influence of the change from socket prosthetics to TOPS for the individual patient. The condition (baseline) immediately before the TOPS fitting is to be recorded on the basis of the existing socket fitting. In the further course of time, the patient is to be accompanied and called in for examinations at three further points in time, which represent special points in time in the rehabilitation plan. By means of a motion analysis, the change in gait pattern over time after the change from the socket to TOPS is observed. In particular, the temporary gait parameters are observed with regard to their symmetry and performance is also measured. It will be examined whether the resulting hip moment correlates with the improvement in gait pattern. By means of MRI imaging and segmentation, the morphology and physiology of the musculature will be examined in the temporal course of fitting and rehabilitation. In particular, muscle thicknesses and fatty degeneration will be elaborated. These studies will show the influence of rehabilitation with TOPS on the individual patient. In addition, the rehabilitation concept will be reviewed in cooperation with the treatment providers and suppliers. By means of an inverse multi-body simulation coupled with a finite element analysis, it will be examined which exercises in rehabilitation and which sports are possible and useful for patients fitted with TOPS.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Jennifer Ernst; Dr. Michael Schwarze; Dr. Marcus Örgel