Comparison of in vivo knee kinematics before and after bicruciate-stabilized total knee arthroplasty during squatting

Comparing Outcomes of Bicruciate-Stabilized and Cruciate-Retaining Total Knee Arthroplasty

Background

Bicruciate-stabilized (BCS) total knee arthroplasty (TKA) aims to restore normal kinematics by replicating the function of both cruciate ligaments. Conventional cruciate-retaining (CR) design in TKA has shown previous clinical success with lower complication rates. This study compared the patient-reported outcomes between the BCS and CR TKA designs.

Methods

This retrospective study examined patients who underwent primary TKA using a CR or a BCS implant. Patient demographics, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), and Forgotten Joint Score (FJS) were compared between two cohorts. Patient-reported outcome measures were analyzed using independent samples t-tests.

Results

There were no significant preoperative demographic differences between groups. The CR cohort (n = 756) had significantly higher average KOOS, JR Scores compared to the BCS cohort (n = 652) at 3 months (59.7 ± 3.8 vs. 53.0 ± 3.9, p < 0.001) and 2 years (62.6 ± 8.0 vs. 53.8 ± 6.7, p = 0.001) after TKA. Within the cohort, KOOS, JR delta differences were not significant for CR when comparing patient scores 3 months to 1 year after surgery. Meanwhile, the BCS patients did show significant delta improvement (4.1 ± 1.9, p = 0.030) when compared 3 months to 1 year after surgery. One year postoperatively, the BCS cohort (n = 134) showed a significantly higher average FJS score (49.5 ± 31.4, vs. 36.8 ± 28.5, p = 0.028) than the CR cohort (n = 203). Both cohorts displayed a significant difference in delta improvements within their respective cohort when measuring FJS from 3 months to 1 year, 2 years, and 3 years after surgery.

Conclusions

The CR cohort performed better on average, compared to the BCS cohort in measures of KOOS, JR scores at the 2-year follow-up. The BCS cohort performed marginally better regarding FJS only at 1-year follow-up.

Comparison of traditional PS versus kinematically designs in primary total knee arthroplasty

PURPOSE

Kinematically designed total knee arthroplasty (TKA) aims to restore normal kinematics by replicating the function of both cruciate ligaments. Traditional posterior-stabilized (PS) TKA designs, on the other hand, simplify knee kinematics and may improve TKA cost-effectiveness. The purpose of this study was to compare outcomes of patients who underwent primary TKA using either a traditional PS or kinematically designed TKA.

METHODS

This retrospective study examined all patients who underwent primary TKA using either a kinematically or a traditional PS designed TKA implant, with a minimum follow-up of 2 years. Patient demographics, complications, readmissions, revision rates and causes, range of motion (ROM) and patient reported outcomes (KOOS, JR) were compared between groups. Kaplan-Meier survivorship analysis was performed to estimate freedom from revision, and multivariate regression was performed to control for confounding variables.

RESULTS

A total of 396 TKAs [173 (43.7%) with a kinematic design, 223 (56.3%) with a traditional design] with a mean follow-up of 3.48 ± 1.51 years underwent analysis. Revision rates did not differ between groups (9.8% vs. 6.7%, p = 0.418). In Kaplan-Meier analysis at 2-year follow-up, freedom from all-cause revision (96.4% vs. 93.1%, p = 0.139) were similar between groups. The two cohorts had no significant difference in aseptic loosening at 2 years (99.6% vs. 97.1, p = 0.050) and at latest follow up (92.7% vs. 96.4%, p = 0.279). KOOS, JR scores and post-operative ROM were similar between groups.

CONCLUSION

This study demonstrated similar mid-term outcomes following the use of both a kinematically designed and a traditionally designed implant in primary TKA patients.

LEVEL OF EVIDENCE

Retrospective study-III.