Evidence map›Paper›PMID 41749321›Full record

ArticleKnee surgery & related research2026

Effect of femoral component design and quadriceps load on patellofemoral kinematics after total knee arthroplasty: an in vitro cadaveric study.

Vera Maioli, Emanuele Diquattro, Michele Conconi, Francesco Castagnini, Francesco Traina, Nicola Sancisi, Luca Cristofolini

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Article in Knee surgery & related research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Vera MaioliDepartment of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum-Università di Bologna, Via Umberto Terracini 24-28, 40131, Bologna, Italy.ORCID https://orcid.org/0000-0003-1328-915X
Emanuele DiquattroOrtopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1, 40136, Bologna, Italy.
Michele ConconiDepartment of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum-Università di Bologna, Via Umberto Terracini 24-28, 40131, Bologna, Italy.ORCID https://orcid.org/0000-0003-2392-2684
Francesco CastagniniOrtopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1, 40136, Bologna, Italy.ORCID https://orcid.org/0000-0002-5767-4052
Francesco TrainaOrtopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1, 40136, Bologna, Italy. francesco.traina@ior.it.ORCID https://orcid.org/0000-0002-0196-101X
Nicola SancisiDepartment of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum-Università di Bologna, Via Umberto Terracini 24-28, 40131, Bologna, Italy.ORCID https://orcid.org/0000-0003-3005-6489
Luca CristofoliniDepartment of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum-Università di Bologna, Via Umberto Terracini 24-28, 40131, Bologna, Italy. luca.cristofolini@unibo.it.ORCID http://orcid.org/0000-0002-7473-6868

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposePatellofemoral (PF) complications are a common cause of dissatisfaction and revision following total knee arthroplasty (TKA), often linked to altered kinematics and implant design. "Patella-friendly" femoral components with a wider, funnel-shaped trochlear groove may better restore native patellar motion. This study evaluated PF kinematics both before and after TKA performed using kinematic alignment, investigating the role of implant design and quadriceps loading.

methodsIn total, 12 paired fresh-frozen cadaveric lower limbs were tested before and after TKA. Within each pair, one limb received a traditional medial pivot femoral component, while the contralateral limb received a "patella-friendly" medial pivot femoral component. Native and implanted knees were tested by flexing the knee under the action of an external load applied through the quadriceps tendon, varying its magnitudes (20, 160, 280N) and directions in the frontal (neutral,±6°, ±12°) and sagittal plane (neutral, +5° anterior). Motion was captured using an eight-camera optoelectronic system.

resultsIn the reference condition (20N, neutral direction), neither design showed statistical differences versus native (p > 0.05). However, the patella excursion in varus-valgus rotation was much higher in the specimens implanted with the traditional femoral component design (35.1° versus 14.6° native) than with the patella-friendly (20.5°). Differences between the designs emerged mainly with quadriceps load variations, especially frontal direction changes, which significantly affected patellar motion in both native and implanted knees (p < 0.05). Overall, the patella-friendly design better reproduced native kinematics under most conditions. However, with extreme medial loading (12°), three out of six specimens implanted with the patella-friendly femoral component were untestable owing to instability, and others exhibited high lateral displacement and trochlear dysplasia. In contrast, all traditional design implants remained stable, though with greater deviation from native kinematics.

conclusionsThis study provides foundational insights into PF biomechanics before and after TKA with kinematic alignment. By analyzing the interplay between implant geometry and quadriceps loading direction, it emphasizes the importance of selecting femoral components on the basis of individual patient anatomy. Our findings suggest that patella-friendly femoral components-although capable of better reproducing native motion in some cases-may not be suitable for patients with medially directed quadriceps forces or severely varus morphotypes.

Indexed as

Femoral components designImplant designKinematic alignmentPatellar trackingPatellofemoral jointQuadriceps loadTotal knee arthroplasty

Identifiers

PMID41749321
PMCPMC12937521

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.