Abstract
Aims and Objectives:
The ischiocrural muscles play an important role in the rotation of the tibia. The main objective of the study was to examine the extent to which an increased cocontraction of the SEMITEN and BIZFEM in patients with bicondylar (TKA) and unicondylar prostheses (UKA) under the influence of everyday forms of stress restricts the tibial rotation.
Materials and Methods:
3-D-motion analysis in patients after TKA or UKA was performed to record joint kinematics before and after knee prosthesis. Inclusion criteria: Age 50-70 years, no other prostheses, BMI <31, no relevant diseases, surgery - period 04/2015 to 04/2016. Out of a total of 550 patients finally 22 patients (w:11/m:11) could be included: TKA (n = 11), UKA (n = 9). To imitate various movement patterns of ADL, a parcour was built with a ramp and a staircase with 3 steps. Kinematic data were recorded with 10 infrared 100 Hz cameras. Muscular activities were measured bilaterally with a wireless EMG system (1000 Hz, myon320, muon, CH). Walking speed was collected through a time-gate system (WEKO, Weitmann & Konrad GmbH & Co. KG, DE).
Static analysis was performed by statistical nonparametric assignment (SnPM). The WOMAC score was used for subjective assessment of dysfunctions.
Results:
In normal walking, there was no difference in tibial rotation compared to the non-operated knee in either the TKA or the UKA group. In SnPM analysis, statistically significantly reduced tibial rotation was shown on the downturn of a ramp in the TKA group at the operated knee. The UKA group showed no significant differences on the ramp to the non-operated knee. Concerning co-contraction of the SEMITEN and BIZFEM in the EMG analysis in the operated knee joint, no deviation from the non-operated knee could be shown.
When climbing stairs, the SnPM internal rotation analysis revealed significant differences between the TKA and the UKA group (stance phase). Similar to the group comparement a restricted axial rotational movement compared to an operated to non - operated knee joint in the TKA - group could be show.n Especially during the stairway, the knee internal rotation of the prosthesis was impaired compared to the non-operated knee. On the other hand, when climbing stairs, the internal rotation was mostly significantly reduced during the stance phase. The SnPM analysis showed statistically significant asymmetries in the UKA group during stairway walking. The disturbed internal rotational movement showed the UKA group in the operated knee joint compared to the un-operated knee joint to the same extent as the TKA group only during the run down from the ramp.
Conclusion:
The assumption that cocontractions between the SEMITEN and the BIZFEM contributes to the impairment of internal rotation can not be confirmed from the data available to us. Other influences must be the cause.