Robotic-assisted knee arthroplasty methods provide insight into Homo neanderthalensis gait and the evolutionary origins of modern human knee variation
Abstract
Lower-limb alignment is central to human bipedal locomotion and a key determinant of joint kinematics and osteoarthritis risk in modern clinical practice. However, its significance in hominins, and therefore its evolutionary implications, remain poorly understood. Advances in robotic-assisted total knee arthroplasty (TKA) provide highly precise measurements of lower-limb alignment, joint morphology and soft-tissue balance that can elucidate these understudied aspects of hominin functional morphology. Here, we perform a proof-of-concept robotic-assisted TKA on an anatomically accurate model of the Spy II Neandertal. Using a robotic-assistance system, we registered bony morphology and replicated soft-tissue laxity extrapolated from a modern patient with a comparable alignment phenotype. We confirmed a pronounced constitutional varus alignment, classifying Spy II as a CPAK type I knee. This phenotype resembles that of modern athletes engaged in significant weight-bearing sports or intense physical activity during growth. The demonstration of constitutional varus in a hominin fossil thus suggests a deep evolutionary origin for this alignment pattern in modern humans, contextualizing normal knee variation and supporting an individualized alignment approach to modern TKA.
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BibTeX
@article{pott2026roboticassisted,
title = {{Robotic-assisted knee arthroplasty methods provide insight into Homo neanderthalensis gait and the evolutionary origins of modern human knee variation}},
author = {Hendrik Pott and Peter Savov and Ricarda Stauss and Laura M. Watson and Ottmar Kullmer and Max Ettinger and Nicole M. Webb and Tara Chapman},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-77544-z},
url = {https://www.nature.com/articles/s41598-026-77544-z},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Robotic-assisted knee arthroplasty methods provide insight into Homo neanderthalensis gait and the evolutionary origins of modern human knee variation
AU - Hendrik Pott
AU - Peter Savov
AU - Ricarda Stauss
AU - Laura M. Watson
AU - Ottmar Kullmer
AU - Max Ettinger
AU - Nicole M. Webb
AU - Tara Chapman
PY - 2026
DA - 2026/10/25
JO - Scientific Reports
DO - 10.1038/s41598-026-77544-z
UR - https://www.nature.com/articles/s41598-026-77544-z
AB - Lower-limb alignment is central to human bipedal locomotion and a key determinant of joint kinematics and osteoarthritis risk in modern clinical practice. However, its significance in hominins, and therefore its evolutionary implications, remain poorly understood. Advances in robotic-assisted total knee arthroplasty (TKA) provide highly precise measurements of lower-limb alignment, joint morphology and soft-tissue balance that can elucidate these understudied aspects of hominin functional morphology. Here, we perform a proof-of-concept robotic-assisted TKA on an anatomically accurate model of the Spy II Neandertal. Using a robotic-assistance system, we registered bony morphology and replicated soft-tissue laxity extrapolated from a modern patient with a comparable alignment phenotype. We confirmed a pronounced constitutional varus alignment, classifying Spy II as a CPAK type I knee. This phenotype resembles that of modern athletes engaged in significant weight-bearing sports or intense physical activity during growth. The demonstration of constitutional varus in a hominin fossil thus suggests a deep evolutionary origin for this alignment pattern in modern humans, contextualizing normal knee variation and supporting an individualized alignment approach to modern TKA.
SN - 2045-2322
ER -