Accuracy of soft tissue balancing in TKA: comparison between navigation-assisted gap balancing and conventional measured resection

Abstract

Equalized rectangular extension and flexion gaps are considered desirable to ensure proper kinematics in total knee arthroplasty (TKA). We compared soft tissue balancing in TKAs performed using navigation-assisted gap-balancing (60 knees) and conventional measured resection (56 knees). The outlier of soft tissue balancing was defined as a gap difference >3 mm between the medial and lateral sides in 90 degrees flexion and extension. Medial or lateral outliers in extension or flexion were observed in 12% (7 of 60) navigation TKAs and 25% (14 of 56) conventional TKAs (p = 0.028). There were more outliers in flexion-extension gap difference on the medial side in the conventional (23%) than in the navigation-assisted (5%) group (p = 0.025). However, the proportion of flexion gap difference, extension gap difference, and lateral gap difference outliers did not differ significantly between the two groups (n.s.). Additionally, clinicoradiologic outcomes were similar for the two groups except for the postoperative mechanical axis outlier (p = 0.012). Navigation-assisted soft tissue balancing in TKA reduced not only the postoperative alignment outlier, but also the medial gap difference and achieved a more rectangular flexion and extension gap compared with conventional TKA.

Is TKA Using Patient-specific Instruments Comparable to Conventional TKA? A Randomized Controlled Study of One System

“…Another difficulty with patient-specific guides is that they do not take into account the effects of soft tissue balancing. The gap-balancing technique has been advocated over the measured resection technique in some studies, including navigation studies, in terms of less abnormal femoral component rotation and coronal instability and better functional outcome [8,10,17,24]. We used the gravity traction method, which uses gravity as a tension force for reproducing a rectangular flexion gap.…”

Soft-tissue balancing in total knee arthroplasty: cruciate-retaining versus posterior-stabilised, and measured-resection versus gap technique

“…As an essential concept in TKA, preparing an equalised rectangular gap in extension and flexion is desirable to ensure proper knee kinematics. Several investigators recently reported that navigation-assisted gap balancing achieved more rectangular extension and flexion gaps compared with the conventional measured-resection technique [32][33][34]. However, these investigators did not assess the difference between PS and CR.…”

Lessons Learned from Selective Soft-Tissue Release for Gap Balancing in Primary Total Knee Arthroplasty

“…oft-tissue releases play an important role in balancing a total knee replacement 1,[3][4][5][6]16,17,[19][20][21] . The objective of our study was to describe the soft-tissue releases necessary to achieve balanced flexion and extension gaps in primary total knee arthroplasty performed with a consistent surgical technique involving measured resection and posterior femoral component referencing.…”