KSSTA - 2026-04-16 - Journal Article
Superior patient-reported clinical outcomes after patient-individual total knee arthroplasty compared with off-the-shelf robotic-assisted total knee arthroplasty in valgus knee phenotypes.
Tuecking LR, Savov P, Hold M, Stauss R, Windhagen H, Ettinger M
Topics
Key Takeaway
Patient-individual TKA with customized trochlear design achieved superior 12-month Kujala scores (79.5 vs. 59.7, p=0.001) and FJS (52.5 vs. 36.0) compared to robotic-assisted off-the-shelf TKA in valgus knees with LDFA <85°.
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Summary
This prospective matched case-control study compared patient-individual posterior-stabilized TKA with individualized trochlear design versus robotic-assisted off-the-shelf TKA in patients with valgus phenotype (LDFA <85°), both using restricted kinematic alignment principles. Groups were matched on anatomical criteria with comparable preoperative HKA (185.6° vs. 188.8°, p=0.060) and LDFA (84.0° vs. 83.7°, p=0.261). At 12 months, patient-individual TKA demonstrated significantly superior scores across all PROMs including FJS (52.5 vs. 36.0), OKS, WOMAC, and Kujala (79.5 vs. 59.7, p=0.001).
Key Limitation
The study cannot isolate whether outcome differences are attributable to the individualized trochlear design specifically, the custom implant geometry overall, or the robotic versus conventional surgical execution, as these variables are confounded within the group assignments.
Original Abstract
PURPOSE
To compare early patient-reported clinical outcomes of patient-individual total knee arthroplasty (TKA) with individualized trochlear design versus robotic-assisted TKA using off-the-shelf implants in patients with valgus knee phenotypes and pronounced femoral valgus (lateral distal femoral angle [LDFA] < 85°) at 3 and 12 months postoperatively in a prospective matched case-control study.
METHODS
This prospective matched case-control study based on predefined anatomical criteria included 42 patients who underwent primary TKA between October 2021 and October 2023. Twenty-one patients received patient-individual posterior-stabilized implants. Twenty-one matched controls underwent robotic-assisted TKA with off-the-shelf implants. All procedures followed restricted kinematic alignment (KA) principles with valgus undercorrection. Primary outcomes were patient-reported scores (Forgotten Joint Score [FJS], Kujala Score, Oxford Knee Score [OKS] and the Western Ontario and McMaster Universities Arthritis Index [WOMAC]), assessed preoperatively and at 3 and 12 months.
RESULTS
Both groups demonstrated comparable preoperative clinical status and comparable degrees of preoperative valgus deformity, with no significant differences in hip-knee-ankle angle (HKA, 185.6 ± 6.3° vs. 188.8 ± 4.1°; p = 0.060) or mechanical LDFA (84.0 ± 0.9° vs. 83.7 ± 1.2°; p = 0.261). At 3 and 12 months, patient-individual total knee arthroplasty (pTKA) demonstrated significantly better scores across all patient-reported outcome measures (PROMs) (p < 0.05). The largest difference was observed in the Kujala score at 12 months (79.5 ± 12.8 vs. 59.7 ± 19.0, p = 0.001). FJS improved more rapidly in the pTKA group (from 9.0 to 49.1 at 3 months, and 52.5 at 12 months) compared to robotic-assisted total knee arthroplasty (rTKA) (26.9 and 36.0, respectively). One revision for suspected infection occurred in the pTKA cohort; none were reported after rTKA.
CONCLUSIONS
Patient-individual TKA with individualized trochlear design achieved superior early functional outcomes compared to robotic-assisted TKA with standard implants in severe valgus morphotypes. Individualized trochlear orientation may improve patellofemoral mechanics and facilitate faster recovery in patients with severe femoral valgus.
LEVEL OF EVIDENCE
Level III.