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. 2024 Dec;32(12):3261-3271.
doi: 10.1002/ksa.12349. Epub 2024 Jul 10.

Mechanically aligned total knee arthroplasty does not yield uniform outcomes across all coronal plane alignment of the knee (CPAK) phenotypes

Edoardo Franceschetti  1   2 , Stefano Campi  1   2 , Giancarlo Giurazza  1   2 , Andrea Tanzilli  1   2 , Pietro Gregori  1   2 , Alice Laudisio  1   2 , Michael T Hirschmann  3   4 , Kristian Samuelsson  5   6 , Rocco Papalia  1   2
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Mechanically aligned total knee arthroplasty does not yield uniform outcomes across all coronal plane alignment of the knee (CPAK) phenotypes

Edoardo Franceschetti et al. Knee Surg Sports Traumatol Arthrosc. 2024 Dec.

Abstract

Purpose: Patient dissatisfaction rates following total knee arthroplasty (TKA) reported in the literature reach 20%. The optimal coronal alignment is still under debate. The aim of this retrospective study was to compare clinical outcomes in different coronal plane alignment of the knee (CPAK) phenotypes undergoing mechanically aligned (MA) TKA. The hypothesis was that knees with preoperative varus arithmetic hip-knee-ankle angle (aHKA) would achieve inferior clinical outcomes after surgery compared to other aHKA categories. Additionally, another objective was to assess CPAK phenotypes distribution in the study population.

Methods: A retrospective selection was made of 180 patients who underwent MA TKA from April 2021 to December 2022, with a 1-year follow-up. Coronal knee alignment was classified according to the CPAK classification. Clinical outcome evaluations were measured using the Knee Society Score (KSS), Oxford Knee Score (OKS), Short Form Survey 12 and Forgotten Joint Score (FJS). Differences in clinical outcomes were considered statistically significant with a p value <0 .05.

Results: Patients with varus aHKA achieved significantly inferior outcomes at final follow-up compared to other aHKA categories in KSS pt. 1 (79.7 ± 17.2 vs. 85.6 ± 14.7; p = 0.028), OKS (39.2 ± 9.2 vs. 42.2 ± 7.2; p = 0.019) and FJS (75.4 ± 31.0 vs. 87.4 ± 22.9; p =0 .003). The most common aHKA category was the varus category (39%). The most common CPAK phenotypes were apex distal Types I (23.9%), II (22.8%) and III (13.3%).

Conclusion: MA TKA does not yield uniform outcomes across all CPAK phenotypes. Varus aHKA category shows significantly inferior results at final follow-up. The most prevalent CPAK categories are varus aHKA and apex distal JLO, with phenotypes I, II and III being the most common. However, their gender distribution varies significantly.

Level of evidence: Level IV.

Keywords: clinical outcomes; coronal plane alignment of the knee (CPAK); knee phenotypes; mechanical alignment (MA); total knee arthroplasty (TKA).

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References

REFERENCES

    1. Beckers, G., Meneghini, R.M., Hirschmann, M.T., Kostretzis, L., Kiss, M.‐O. & Vendittoli, P.‐A. (2024) Ten flaws of systematic mechanical alignment total knee arthroplasty. The Journal of Arthroplasty, 39(3), 591–599. Available from: https://doi.org/10.1016/j.arth.2023.11.023
    1. Blakeney, W., Clément, J., Desmeules, F., Hagemeister, N., Rivière, C. & Vendittoli, P.‐A. (2019) Kinematic alignment in total knee arthroplasty better reproduces normal gait than mechanical alignment. Knee Surgery, Sports Traumatology, Arthroscopy, 27(5), 1410–1417. Available from: https://doi.org/10.1007/s00167-018-5174-1
    1. Bonner, T.J., Eardley, W.G.P., Patterson, P. & Gregg, P.J. (2011) The effect of post‐operative mechanical axis alignment on the survival of primary total knee replacements after a follow‐up of 15 years. The Journal of Bone and Joint Surgery. British Volume, 93(9), 1217–1222. Available from: https://doi.org/10.1302/0301-620X.93B9.26573
    1. Bourne, R.B., Chesworth, B.M., Davis, A.M., Mahomed, N.N. & Charron, K.D.J. (2010) Patient satisfaction after total knee arthroplasty: who is satisfied and who is not? Clinical Orthopaedics & Related Research, 468(1), 57–63. Available from: https://doi.org/10.1007/s11999-009-1119-9
    1. Calliess, T., Bauer, K., Stukenborg‐Colsman, C., Windhagen, H., Budde, S. & Ettinger, M. (2017) PSI kinematic versus non‐PSI mechanical alignment in total knee arthroplasty: a prospective, randomized study. Knee Surgery, Sports Traumatology, Arthroscopy, 25(6), 1743–1748. Available from: https://doi.org/10.1007/s00167-016-4136-8

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