Myriam Cilla1, Sara Checa2, Bernd Preininger3, Tobias Winkler4, Carsten Perka5, Georg N Duda6, Matthias Pumberger7. 1. Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Berlin, Germany; Centro Universitario de la Defensa (CUD) de Zaragoza, Academia General Militar de Zaragoza, Spain; Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain. 2. Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Berlin, Germany. 3. Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany. 4. Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany; Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Berlin, Germany. 5. Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany; Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany; Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Berlin, Germany. 6. Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany; Julius Wolff Institute, Charité - Universitätsmedizin Berlin, Berlin, Germany. 7. Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany; Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany. Electronic address: matthias.pumberger@charite.de.
Abstract
BACKGROUND: Femoral head necrosis is a common cause of secondary osteoarthritis. At the early stages, treatment strategies are normally based on core decompression techniques, where the number, location and diameter of the drilling holes varies depending on the selected approach. The purpose of this study was to investigate the risk of femoral head, neck and subtrochanteric fracture following six different core decompression techniques. MATERIALS: Five common and a newly proposed techniques were analyzed in respect to their biomechanical consequences using finite element analysis. The geometry of a femur was reconstructed from computed-tomography images. Thereafter, the drilling configurations were simulated. The strains in the intact and drilled femurs were determined under physiological, patient-specific, muscle and joint contact forces. FINDINGS: The following results were observed: i) - an increase in collapse and fracture risk of the femur head by disease progression ii) - for a single hole approach at the subtrochanteric region, the fracture risk increases with the diameter iii) - the highest fracture risks occur for an 8mm single hole drilling at the subtrochanteric region and approaches with multiple drilling at various entry points iv) - the proposed novel approach resulted in the most physiological strains (closer to the experienced by the healthy bone). INTERPRETATION: Our results suggest that all common core decompression methods have a significant impact on the biomechanical competence of the proximal femur and impact its mechanical potential. Fracture risk increases with drilling diameter and multiple drilling with smaller diameter. We recommend the anterior approach due to its reduced soft tissue trauma and its biomechanical performance.
BACKGROUND:Femoral head necrosis is a common cause of secondary osteoarthritis. At the early stages, treatment strategies are normally based on core decompression techniques, where the number, location and diameter of the drilling holes varies depending on the selected approach. The purpose of this study was to investigate the risk of femoral head, neck and subtrochanteric fracture following six different core decompression techniques. MATERIALS: Five common and a newly proposed techniques were analyzed in respect to their biomechanical consequences using finite element analysis. The geometry of a femur was reconstructed from computed-tomography images. Thereafter, the drilling configurations were simulated. The strains in the intact and drilled femurs were determined under physiological, patient-specific, muscle and joint contact forces. FINDINGS: The following results were observed: i) - an increase in collapse and fracture risk of the femur head by disease progression ii) - for a single hole approach at the subtrochanteric region, the fracture risk increases with the diameter iii) - the highest fracture risks occur for an 8mm single hole drilling at the subtrochanteric region and approaches with multiple drilling at various entry points iv) - the proposed novel approach resulted in the most physiological strains (closer to the experienced by the healthy bone). INTERPRETATION: Our results suggest that all common core decompression methods have a significant impact on the biomechanical competence of the proximal femur and impact its mechanical potential. Fracture risk increases with drilling diameter and multiple drilling with smaller diameter. We recommend the anterior approach due to its reduced soft tissue trauma and its biomechanical performance.
Authors: Samuel A Hockett; John T Sherrill; Micah Self; Simon C Mears; C Lowry Barnes; Erin M Mannen Journal: J Mech Behav Biomed Mater Date: 2020-12-11
Authors: Michael A Mont; Hytham S Salem; Nicolas S Piuzzi; Stuart B Goodman; Lynne C Jones Journal: J Bone Joint Surg Am Date: 2020-06-17 Impact factor: 6.558