Abstract
Purpose Of Study
The in vivo evaluation of patellofemoral contact pressures in a posterior stabilized compared to posterior cruciate sacrificing total knee arthroplasty (TKA).
Methods
A prospective descriptive non randomized study was performed on 8 patients. A standard approach to a TKA was performed using a balanced gap technique, while the patella was prepared for a resurfacing. The trial components for the posterior stabilized (PS) TKA where inserted including the gas sterilized pressure transducer (a patella button). Soft tissue was approximated and the knee was taken through full range of movement. Patellofemoral pressure was measured and captured continuously through the full range of movement. The posterior cruciate sacrificing (CS) components were inserted into the same patient and the procedure repeated. In addition, anterior translation of the tibia relative to the femur was measured at 90 degrees. The transducer was removed and final components, including a patella resurfacing were inserted.
Results
Significantly lower patella femoral pressures were found for PS TKA compared to CS TKA in full flexion [129.0 ± 21.7 N vs. 109.9 ± 32.1 (p = 0.038173)].
The change in patellofemoral pressure between flexion and extension was significantly lower in PS TKA compared to CS TKA [109.0 ± 21.6 N vs. 90.5 ± 32.0 (p = 0.0037690)]. In addition mean anterior translation at 90° flexion in the CS TKA (6.4 ± 3.2 mm) was significantly less than in PS TKA (17.0 ± 2.6) (p = 0.000072)
Conclusion
Significantly lower patellofemoral pressures were found in full flexion with PS TKA compared to CS TKA. The change in patellofemoral pressure in a PS TKA compared to CS TKA was also significantly lower.
This study provides possible clinical data when considering patella resurfacing.
NO DISCLOSURES
