Short-term follow-up of kinematically vs. mechanically aligned total knee arthroplasty with medial pivot components: A case-control study

Dragan V Jeremić; Wissam M Massouh; Sivan Sivaloganathan; Almeric R Rosali; Rolf G Haaker; Charles Rivière

doi:10.1016/j.otsr.2020.04.005

Short-term follow-up of kinematically vs. mechanically aligned total knee arthroplasty with medial pivot components: A case-control study

Orthop Traumatol Surg Res. 2020 Sep;106(5):921-927. doi: 10.1016/j.otsr.2020.04.005. Epub 2020 Jun 7.

Authors

Dragan V Jeremić¹, Wissam M Massouh², Sivan Sivaloganathan³, Almeric R Rosali², Rolf G Haaker², Charles Rivière⁴

Affiliations

¹ Clinic for Orthopedic Surgery, St.-Vincenz Hospital, Brakel, Germany. Electronic address: d.jeremic@khwe.de.
² Clinic for Orthopedic Surgery, St.-Vincenz Hospital, Brakel, Germany.
³ South West London Elective Orthopedic Centre, Dorking road, Epsom, UK.
⁴ MSK Lab - Imperial College London, White City Campus, The Lister Hospital, Chelsea Bridge, London, UK; Centre de l'Arthrose, Bordeaux-Mérignac, France.

PMID: 32522532
DOI: 10.1016/j.otsr.2020.04.005

Abstract

Introduction: The kinematic alignment (KA) technique for total knee arthroplasty (TKA) and the medial pivot (MP) component design are two options promoting a physiologic prosthetic knee kinematics when used in combination that could improve TKA outcomes. Case-control study is initiated to compare the 1-year radio-clinical outcomes between kinematic alignment medial pivot total knee arthroplasty (KA MP-TKAs) and mechanical alignment medial pivot total knee arthroplasty (MA MP-TKA). Goal of a study was to answer the following questions: Do KA MP-TKAs patients have improved functional outcomes compared to MA MP-TKAs patients? (Q1); Do prosthetic knee and lower limb alignments differ between KA and MA patients (Q2)? And does kinematic implantation of MP TKA has higher risk of reoperations and revisions (Q3)?

Material and methods: A case-control study was carried out to compare the 1-year clinical and radiographic outcomes between 24 consecutive KA-TKA patients and 24 matched MA-TKA patients. All patients had implantation with manual instruments and a cemented medial pivot TKA with excision of the PCL. All data were collected prospectively, and outcome scores were patient reported.

Results: KA patients had superior values in Forgotten Joint Score (FJS) at 1-year (KA 77 vs. MA 51) (p=0.05) follow-up. After one year KA patients scored better in objective section of the new Knee Society Score (KSS) (p=0.02), and in sport section of the Knee Osteoarthritis Outcome Score (KOOS) (p=0.01). Eleven out of 24 patients (46%) in KA group and 7/24 patients (29%) in MA group had limb alignment out of 180°±3°, whereas 17/24 (70%) of KA patients, and 14/24 (58%) of MA patients had orientation of tibial component with more than 3° of varus. No reoperation or revision occurred in either group.

Discussion/conclusion: The KA of MP TKA design seems to have a good efficacy at early-term, with some 1-year functional performance higher to the ones from MA MP TKAs. Further research is needed to define if those early results will last over time.

Level of evidence: III, case-controlled study.

Keywords: Functional outcomes; Kinematic alignment; Medial pivot; Total knee replacement.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arthroplasty, Replacement, Knee*
Biomechanical Phenomena
Case-Control Studies
Follow-Up Studies
Humans
Knee Joint / diagnostic imaging
Knee Joint / surgery
Knee Prosthesis*
Osteoarthritis, Knee* / surgery
Range of Motion, Articular