Hannes A Rüdiger1,2, Maïka Guillemin3, Adeliya Latypova3, Alexandre Terrier3. 1. Department of Orthopaedics and Traumatology, Centre Hospitalier Universitaire Vaudois CHUV, Av. Pierre Decker 4, Lausanne, 1011, Switzerland. Hannes.Ruediger@kws.ch. 2. Department of Orthopaedic Surgery, Schulthess Clinic, Lengghalde 2, Zurich, 8008, Switzerland. Hannes.Ruediger@kws.ch. 3. Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 15, Lausanne, 1015, Switzerland.
Abstract
BACKGROUND: Anatomical reconstruction in total hip arthroplasty (THA) allows for physiological muscle function, good functional outcome and implant longevity. Quantitative data on the effect of a loss or gain of femoral offset (FO) are scarce. The aim of this study was to quantitatively describe the effect of FO changes on abductor moment arms, muscle and joint reactions forces. METHODS: THA was virtually performed on 3D models built from preoperative CT scans of 15 patients undergoing THA. Virtual THA was performed with a perfectly anatomical reconstruction, a loss of 20% of FO (-FO), and a gain of 20% of FO (+FO). These models were combined with a generic musculoskeletal model (OpenSim) to predict moment arms, muscle and joint reaction forces during normal gait cycles. RESULTS: In average, with -FO reconstructions, muscle moment arms decreased, while muscle and hip forces increased significantly (p < 0.001). We observed the opposite with +FO reconstructions. Gluteus medius was more affected than gluteus minimus. -FO had more effect than +FO. A change of 20% of FO induced an average change 8% of abductor moment arms, 16% of their forces, and 6% of the joint reaction force. CONCLUSIONS: To our knowledge, this is the first report providing quantitative data on the effect of FO changes on muscle and joint forces during normal gait. A decrease of FO necessitates an increase of abductor muscle force to maintain normal gait, which in turn increases the joint reaction force. This effect underscores the importance of an accurate reconstruction of the femoral offset.
BACKGROUND: Anatomical reconstruction in total hip arthroplasty (THA) allows for physiological muscle function, good functional outcome and implant longevity. Quantitative data on the effect of a loss or gain of femoral offset (FO) are scarce. The aim of this study was to quantitatively describe the effect of FO changes on abductor moment arms, muscle and joint reactions forces. METHODS: THA was virtually performed on 3D models built from preoperative CT scans of 15 patients undergoing THA. Virtual THA was performed with a perfectly anatomical reconstruction, a loss of 20% of FO (-FO), and a gain of 20% of FO (+FO). These models were combined with a generic musculoskeletal model (OpenSim) to predict moment arms, muscle and joint reaction forces during normal gait cycles. RESULTS: In average, with -FO reconstructions, muscle moment arms decreased, while muscle and hip forces increased significantly (p < 0.001). We observed the opposite with +FO reconstructions. Gluteus medius was more affected than gluteus minimus. -FO had more effect than +FO. A change of 20% of FO induced an average change 8% of abductor moment arms, 16% of their forces, and 6% of the joint reaction force. CONCLUSIONS: To our knowledge, this is the first report providing quantitative data on the effect of FO changes on muscle and joint forces during normal gait. A decrease of FO necessitates an increase of abductor muscle force to maintain normal gait, which in turn increases the joint reaction force. This effect underscores the importance of an accurate reconstruction of the femoral offset.
Authors: Jakub Tatka; Dimitri Delagrammaticas; Bryson R Kemler; Samuel I Rosenberg; Alex W Brady; Anna R Bryniarski; Grant J Dornan; Joel M Matta Journal: Arthroplasty Date: 2022-06-01
Authors: Stefan van Drongelen; Hanna Kaldowski; Timur Tarhan; Ayman Assi; Andrea Meurer; Felix Stief Journal: BMC Musculoskelet Disord Date: 2019-11-10 Impact factor: 2.362
Authors: Stefan Blümel; Vincent A Stadelmann; Marco Brioschi; Alexander Küffer; Michael Leunig; Hannes A Rüdiger Journal: BMC Musculoskelet Disord Date: 2021-03-29 Impact factor: 2.362