Restricted kinematic alignment is clinically non-inferior to mechanical alignment in the short and mid-term: A systematic review

Gabriele Cortina; Pierangelo Za; Giuseppe Francesco Papalia; Pietro Gregori; Vincenzo Condello; Sebastiano Vasta; Edoardo Franceschetti; Stefano Campi; Vincenzo Madonna; Rocco Papalia

doi:10.1016/j.knee.2023.10.003

Restricted kinematic alignment is clinically non-inferior to mechanical alignment in the short and mid-term: A systematic review

Knee. 2023 Dec:45:137-146. doi: 10.1016/j.knee.2023.10.003. Epub 2023 Nov 3.

Affiliations

¹ Department of Orthopaedic and Trauma Surgery, Università Campus Bio-Medico di Roma, Rome, Italy; Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy.
² Department of Orthopaedic and Trauma Surgery, Università Campus Bio-Medico di Roma, Rome, Italy; Research Unit of Orthopaedic and Trauma Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, Rome, Italy. Electronic address: g.papalia@unicampus.it.
³ Department of Orthopaedic, Joint Prosthetic, Arthroscopic Surgery and Sports Traumatology, Humanitas Castelli, Bergamo, Italy.

PMID: 37925804
DOI: 10.1016/j.knee.2023.10.003

Abstract

Background: In recent years, kinematic alignment (KA) is becoming a valid alternative to mechanical alignment (MA) in total knee arthroplasty (TKA). However, to avoid early failures, the restricted kinematic alignment (rKA) approach has been developed to restore native knee kinematics without reproducing extreme knee phenotype. This systematic review aims to evaluate clinical and radiological outcomes between rKA and MA for TKA.

Methods: A systematic literature search was conducted following PRISMA guidelines on Pubmed, Scopus and Cochrane Library. The following search string was adopted: (((restricted kinematic) AND (mechanical)) AND (alignment)) AND (knee). We included studies that analyzed rKA versus MA in terms of clinical outcomes and complications with a minimum of 6 months of follow up. The following rKA- and MA-related data were evaluated: patient-reported outcome scores (PROMs), radiographic analysis of lower limb alignment, and complications. Criteria from the Methodological Index for Non-Randomized Studies were used to assess the methodological quality of the articles.

Results: This systematic review included seven clinical studies with a total of 892 knees (471 for MA group and 421 for rKA group, respectively). Overall, post-operative PROMs were similar between rKA and MA. Moreover, rKA reached better results regarding Forgotten Joint Score and post-operative patient satisfaction. Finally, no higher complication rate was observed with the rKA approach.

Conclusion: The rKA aims to restore native knee kinematics, avoiding extreme deformities. Clinical outcomes are not inferior or even better for rKA compared with MA, without increasing the risk of short-middle-term implant failure. However, there is a high heterogeneity regarding the 'restricted' protocols used.

Keywords: Clinical outcomes; Mechanical alignment; Restricted kinematic; Systematic review; Total knee arthroplasty.

Publication types

Systematic Review
Review

MeSH terms

Arthroplasty, Replacement, Knee* / methods
Biomechanical Phenomena
Humans
Knee Joint / diagnostic imaging
Knee Joint / surgery
Knee Prosthesis*
Lower Extremity
Osteoarthritis, Knee* / surgery
Radiography