Revision Total Knee Arthroplasty Using an Implant-Agnostic, Joint-Line Based, Gap-Balanced Technique

Purpose: Instability is a significant cause of failure following revision total knee arthroplasty and results in the lowest patient satisfaction. This study validates, under controlled cadaveric parameters, a joint-line based, gap-balancing technique for performing revision total knee arthroplasty using an implant-agnostic workflow. Materials and Methods: A cadaveric feasibility study was completed with eight lower extremities previously prepared for total knee arthroplasty in kinematic alignment undergoing revision total knee arthroplasty to mechanical alignment with a joint-line based, gap-balanced workflow. A step-by-step guide for this technique was documented and performed, and accuracy of the approach was quantified in all cases. Results: After bone preparation, the measured gaps were all within 1mm of the desired measurement (medial extension 0.38mm, lateral extension 0.63mm, medial flexion 0.75mm, and lateral flexion 0.25mm), accepting the pre-calculated implant and augment sizes. There were no adjustments needed to bone cuts or soft tissues in any specimen. Of interest, 10mm posterolateral augments were required in all specimens. Conclusions: The technique described in this study showed promising accuracy in a series of cadaveric specimens. With additional clinical testing, this approach to revision total knee arthroplasty could prove to reduce the need for re-revision and improve patient satisfaction.