A Comparison of Rollback Ratio between Bicruciate Substituting Total Knee Arthroplasty and Oxford Unicompartmental Knee Arthroplasty

Abstract

The purpose of this study was to compare the rollback ratio in bicruciate substituting (BCS) total knee arthroplasty (TKA) and bicruciate-retaining Oxford unicompartmental knee arthroplasty (UKA). In this study, 64 subjects (64 knees) undergoing BCS-TKA (Journey II: Smith and Nephew) and 50 subjects (50 knees) undergoing Oxford UKA (Zimmer-Biomet holdings, Inc., IN) were included. Approximately 6 months after surgery, and when the subjects had recovered their knee range of motion, following the Laidlow's method, lateral radiographic imaging of the knee was performed with active full knee flexion. The most posterior tibiofemoral contact point was measured for the evaluation of femoral rollback (rollback ratio). Flexion angle was also measured using the same radiograph and the correlation of rollback and flexion angle was analyzed. As a control, radiographs of the asymptomatic contralateral knees of subjects undergoing Oxford UKA were evaluated (50 knees). The rollback ratios of the BCS-TKA, Oxford UKA, and control knees were 37.9 ± 4.9, 35.7 ± 4.2, and 35.3 ± 4.8% respectively. No significant difference in rollback ratio was observed among the three groups. The flexion angles of the BCS-TKA, Oxford UKA, and control knees were 123.8 ± 8.4, 125.4 ± 7.5, and 127 ± 10.3 degrees, respectively. No significant difference in knee flexion angle was observed among the three groups. Significant correlation between rollback ratio and knee flexion angle was observed ( = 0.002; Pearson's correlation coefficient = - 0.384). BCS-TKA showed no significant difference in rollback ratio when compared with control knees and Oxford UKA knees. The BCS-TKA design is likely to reproduce native anterior cruciate ligament and posterior cruciate ligament function, and native knee rollback.

The evaluation of the distance between the popliteus tendon and the lateral collateral ligament footprint and the implant in Total Knee Arthroplasty using a 3-dimensional template.

“…Although the excellent anatomical evaluation has been reported concerning PT or LCL morphology, to the best of our knowledge, not many studies have approached the correlation of morphology with TKA implants [17]. In the Journey BCS, distal and posterior bone cut thickness was 7.0mm and 7.4mm, respectively [10,19]. In the Persona PS, the distal and posterior bone cut thickness was 9.0mm and 10.0mm [9], respectively.…”

“…In the bone cut simulation bone, distal femoral bone cut thickness was 7.0mm for the Journey II BCS and 9.0mm for the Persona PS, respectively. Posterior bone cut thickness was 7.4mm for the Journey II BCS and 10.0mm for the Persona PS [9,10]. In the TKA simulating, the valgus angle to the femoral shaft was 6° and the external rotation angle was 3° from the posterior femoral condyle axis for both models.…”

“…For the surgical treatment of osteoarthritic changes in the knee joint, total knee arthroplasty (TKA) is well known for its excellent clinical results and long-term survival rates [3,10,14,16,19]. When surgeons perform TKA, iatrogenic injury of the PT or LCL is a risk because the femoral attachments are relatively close to the femoral bone resection area.…”

The evaluation of the distance between the popliteus tendon and the lateral collateral ligament footprint and the implant in Total knee Arthroplasty using a 3-dimensional template

“…In the bone cut simulation bone, distal femoral bone cut thickness was 7.0 mm for the Journey II BCS and 9.0 mm for the Persona PS, respectively. Posterior bone cut thickness was 7.4 mm for the Journey II BCS and 10.0 mm for the Persona PS [11]. In the TKA simulating, the valgus angle to the femoral shaft was 6°and the external rotation angle was 3°from the posterior femoral condyle axis for both models.…”

“…For the surgical treatment of osteoarthritic changes in the knee joint, total knee arthroplasty (TKA) is well known for its excellent clinical results and long-term survival rates [10][11][12][13][14]. When surgeons perform TKA, iatrogenic injury of the PT or LCL is a risk because the femoral attachments are relatively close to the femoral bone resection area.…”