Gap balancing versus measured resection technique using a mobile-bearing prosthesis in computer-assisted surgery

Abstract

Navigation has been developed to help surgeons install implants more accurately and reproducibly; at the same time, this tool is able to record quantitative information such as joint range of motion, laxity and kinematics intra-operatively. As for standard surgery, two strategies are possible to achieve either femoral component rotation or overall prosthetic alignment: a measured gap resection approach, in which bone landmarks are used to guide resections equal to the distal and posterior thickness of the femoral component, or a gap-balancing technique, in which equal collateral ligament tension in flexion and extension is tried to find before as a guide to final bone cuts. The purpose of this paper is to compare the two different methods in a 67 patients group submitted to the same procedure using mobile-bearing (MB) prosthesis in order to analyse the effect of both techniques on joint line maintenance, axial limb restoration and components position. The gap group (GG) consists of 31 patients in whom the arthroplasty was performed using a navigated gap-balancing technique. The measured group (MG) consists of 36 patients in whom a computer-assisted measured resection technique was used. The results of imaging and the number of outliers were not statistically different (P = 0.56) for the mechanical axis and prosthetic positioning between the two groups. The gap technique showed a statistically significant alteration of the post-operative value when compared with the measured resection technique, (P = 0.036). The mean elevation of the joint line was 4.09 mm for the GG and 3.50 mm in the MG.

Application of different patella height indices in patients undergoing total knee arthroplasty

“…Joint line elevation caused by TKA is not uncommon; the incidence can reach 40% after primary TKA [ 13 , 36 – 38 ]. Kawamura and Bourne [ 39 ] reported a mean joint line elevation of 3.5 mm, Sabbioni et al [ 40 ] reported 4.0 mm, and Scuderi and Insall [ 41 ] reported 5.6 mm.…”

Comparison of Gap Balancing vs Measured Resection Technique in Patients Undergoing Simultaneous Bilateral Total Knee Arthroplasty: One Technique per Knee

“…Sabbioni et al reported joint line elevation to be 4.09 mm in the GB technique and 3.50 mm in the MR technique using a posterior stabilized knee system. This change was significantly greater for GB knees (P ¼ .036) [44]. Tigani et al also compared the GB and MR techniques performed with CAS-TKA and found that although both led to joint line elevation, there was statistically greater elevation in GB knees (P ¼ .008) [19].…”

A new method for evaluation of patellar height and the position of the joint line before and after total knee arthroplasty

“…Compared with the tibial plateau, the bular head is independent of TKA, as well as osteophytes or the destruction of tibiofemoral articular surface. And the recognition of the styloid process of bular head is accurately acquired on the standard lateral radiograph [20,30]. In this study, the tibial shaft axis was determined by selecting two mid-diaphyseal points at 70-and 110-mm distal to the tibial plateau down the tibial shaft, in which could avoid an increase of the measurement variability, as described by previous studies [22,23].…”