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The influence of component alignment on patellar kinematics in total knee arthroplasty.

Keshmiri A, Maderbacher G, Baier C, Sendtner E, Schaumburger J, Zeman F, Grifka J, Springorum HR - Acta Orthop (2015)

Bottom Line: After TKA, the patellae shifted statistically significantly more laterally between 30° and 60°.Sagittal component alignment, but not rotational component alignment, had a significant influence on patellar kinematics.Combined sagittal component alignment in particular appears to have a major effect on patellar kinematics.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery and.

ABSTRACT

Background and purpose: Postoperative anterior knee pain is one of the most frequent complications after total knee arthroplasty (TKA). Changes in patellar kinematics after TKA relative to the preoperative arthritic knee are not well understood. We compared the patellar kinematics preoperatively with the kinematics after ligament-balanced navigated TKA.

Patients and methods: We measured patellar tracking before and after ligament-balanced TKA in 40 consecutive patients using computer navigation. Furthermore, the influences of different femoral and tibial component alignment on patellar kinematics were analyzed using generalized linear models.

Results: After TKA, the patellae shifted statistically significantly more laterally between 30° and 60°. The lateral tilt increased at 90° of flexion whereas the epicondylar distance decreased between 45° and 75° of flexion. Sagittal component alignment, but not rotational component alignment, had a significant influence on patellar kinematics.

Interpretation: There are major differences in patellar kinematics between the preoperative arthritic knee and the knee after TKA. Combined sagittal component alignment in particular appears to have a major effect on patellar kinematics. Surgeons should be especially aware of altering preoperative sagittal alignment until the possible clinical relevance has been investigated.

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Related in: MedlinePlus

Pre- and postoperative patellar kinematics (mediolateral shift: medial, +; lateral, −; axial tilt: medial, −; lateral, +; coronal rotation: external, −; internal, +; epicondylar distance (mm) during range of motion: open triangle (preoperatively) and closed circle (postoperatively)). Mean values with standard errors. Asterisks above the x-axis indicate significant differences during range of motion.
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Figure 3: Pre- and postoperative patellar kinematics (mediolateral shift: medial, +; lateral, −; axial tilt: medial, −; lateral, +; coronal rotation: external, −; internal, +; epicondylar distance (mm) during range of motion: open triangle (preoperatively) and closed circle (postoperatively)). Mean values with standard errors. Asterisks above the x-axis indicate significant differences during range of motion.

Mentions: There was a statistically significant difference between preoperative and postoperative mediolateral patellar shift between 30° and 60° of flexion; postoperatively, the patellae shifted more laterally throughout the whole motion cycle compared to the arthritic knee. Interestingly, a decrease in epicondylar distance during the whole motion cycle with significant values between 45° and 75° of flexion was observed after TKA. After implantation, the patellae tilted more laterally at flexion angles between 30° to 60°. However, from 60° to 90° of flexion, the patellae tilted more medially compared to the preoperative values—with statistical significance at 90°. Furthermore, the patellae rotated more medially at all flexion angles after TKA, but this was not statistically significant (Table 1, Figure 3).


The influence of component alignment on patellar kinematics in total knee arthroplasty.

Keshmiri A, Maderbacher G, Baier C, Sendtner E, Schaumburger J, Zeman F, Grifka J, Springorum HR - Acta Orthop (2015)

Pre- and postoperative patellar kinematics (mediolateral shift: medial, +; lateral, −; axial tilt: medial, −; lateral, +; coronal rotation: external, −; internal, +; epicondylar distance (mm) during range of motion: open triangle (preoperatively) and closed circle (postoperatively)). Mean values with standard errors. Asterisks above the x-axis indicate significant differences during range of motion.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4513599&req=5

Figure 3: Pre- and postoperative patellar kinematics (mediolateral shift: medial, +; lateral, −; axial tilt: medial, −; lateral, +; coronal rotation: external, −; internal, +; epicondylar distance (mm) during range of motion: open triangle (preoperatively) and closed circle (postoperatively)). Mean values with standard errors. Asterisks above the x-axis indicate significant differences during range of motion.
Mentions: There was a statistically significant difference between preoperative and postoperative mediolateral patellar shift between 30° and 60° of flexion; postoperatively, the patellae shifted more laterally throughout the whole motion cycle compared to the arthritic knee. Interestingly, a decrease in epicondylar distance during the whole motion cycle with significant values between 45° and 75° of flexion was observed after TKA. After implantation, the patellae tilted more laterally at flexion angles between 30° to 60°. However, from 60° to 90° of flexion, the patellae tilted more medially compared to the preoperative values—with statistical significance at 90°. Furthermore, the patellae rotated more medially at all flexion angles after TKA, but this was not statistically significant (Table 1, Figure 3).

Bottom Line: After TKA, the patellae shifted statistically significantly more laterally between 30° and 60°.Sagittal component alignment, but not rotational component alignment, had a significant influence on patellar kinematics.Combined sagittal component alignment in particular appears to have a major effect on patellar kinematics.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery and.

ABSTRACT

Background and purpose: Postoperative anterior knee pain is one of the most frequent complications after total knee arthroplasty (TKA). Changes in patellar kinematics after TKA relative to the preoperative arthritic knee are not well understood. We compared the patellar kinematics preoperatively with the kinematics after ligament-balanced navigated TKA.

Patients and methods: We measured patellar tracking before and after ligament-balanced TKA in 40 consecutive patients using computer navigation. Furthermore, the influences of different femoral and tibial component alignment on patellar kinematics were analyzed using generalized linear models.

Results: After TKA, the patellae shifted statistically significantly more laterally between 30° and 60°. The lateral tilt increased at 90° of flexion whereas the epicondylar distance decreased between 45° and 75° of flexion. Sagittal component alignment, but not rotational component alignment, had a significant influence on patellar kinematics.

Interpretation: There are major differences in patellar kinematics between the preoperative arthritic knee and the knee after TKA. Combined sagittal component alignment in particular appears to have a major effect on patellar kinematics. Surgeons should be especially aware of altering preoperative sagittal alignment until the possible clinical relevance has been investigated.

Show MeSH
Related in: MedlinePlus