The impact of implant design consistency in staged bilateral total knee arthroplasty on gait patterns and functional outcomes: A comparative analysis

Background: The aim of this study was to assess whether there are any differences in plantar pressure distribution and gait cycle between patients with the same implant design and patients with different designs in staged bilateral TKA and to examine the impact of these differences on clinical and functional outcomes.

Methods: A retrospective review was conducted of all patients who underwent staged bilateral TKA. The patients were divided into two groups based on the prosthesis design used in both knees. A comparison was made between the two groups regarding various factors, including demographic data, radiological measurements, functional scores, gait analysis, and plantar pressure mapping.

Results: Patients with the same implant design were found to have statistically significantly higher functional scores (p = 0.001). Furthermore, the difference in pre-swing phase plantar distribution for both extremities in patients with different implant designs was found to be greater than in those with the same implant design (p = 0.031). Similarly, the difference in initial contact phase load distribution between the different implant design groups was found to be significantly higher than that observed in the same implant design group (p = 0.014).

Conclusion: In conclusion, individuals with two different implant designs in staged bilateral TKA showed a substantial imbalance in gait cycle and plantar pressure distribution. This may result in various consequences, including impairment in movement, patient dissatisfaction, and even early implant failure. Therefore, the same implant design should be used as much as possible to achieve balanced knee kinematics and favorable outcomes.