Dr. Russell Bodner & Dr. Spencer Montgomery — AAOS JOEI Mixer, San Diego 2025
CupCalc brings published spinopelvic science directly to your finger tips. Here's the team behind it.
Acetabular cup positioning has long relied on population-based targets that ignore individual spinopelvic mechanics. A growing body of published research has changed that — defining patient-specific functional targets based on pelvic incidence, sacral slope, and femoral mobility. While 3-dimensional CT based planning tools have advanced our understanding of patient-specific anatomy, anatomy alone does not fully capture the nuances of how an individual actually moves. The published math bridges that gap and CupCalc puts that framework in your hands. This educational reference is designed to help surgeons understand specific mobility patterns and the biomechanical principles behind optimal cup positioning.
Dr. Montgomery is a hip and knee reconstruction specialist and he completed his orthopaedic surgery residency and medical degree at the University of Calgary, followed by a Lower Extremity Reconstruction Fellowship at St. Michael's Hospital, University of Toronto and the Stanford Biodesign Innovation Fellowship. He served as an assistant professor of orthopaedic surgery at the University of Mississippi Medical Center prior to starting his private practice. He serves as an advisor and consultant for multiple medical companies and startups.
Dr. Montgomery developed CupCalc to translate the spinopelvic planning framework of Dr. Bodner and others into an accessible clinical tool.
Dr. Bodner was a former Health System Clinician in the Department of Orthopaedic Surgery at Northwestern University's Feinberg School of Medicine, retiring after over 35 years of clinical service in orthopaedic surgery. He completed his medical degree at UCLA, his residency at the University of Pennsylvania, and pursued fellowships in AO trauma and sports medicine under Dr. Richard Steadman.
A leading voice in spinopelvic functional planning, Dr. Bodner has published extensively in the Journal of Arthroplasty and the Journal of Bone & Joint Surgery, and has presented at AAOS, ISTA, and international arthroplasty symposia. He developed the Dr. Bodner holds an international patent family covering methods and systems for sagittal-plane acetabular component targeting in total hip arthroplasty, including the sacroacetabular angle construct and its application to patient-specific functional planning. His patented framework mathematically integrates pelvic morphology, standing spatial position, and postural mobility into a unified geometric model that determines individualized cup orientation targets for both standing and sitting positions.