Abstract
Introduction
Functional stability is a new concept stating that lower tensions than expected are enough to achieve joint stability leading to proper function after TKA. To check this rationale clinically, a new electronic device (DLB bicon sensorplate) was used intraoperatively to measure ligament tension and allow the surgeon to proper balance the knee after TKA insertion. In this study a controlled clinical analysis at 1 YR follow-up is reported.
Methods
A cohort of 25 patients was treated in a single centre, single surgeon study to quantify the influence of the use of this electronic device in the short- and midterm results (DLB Group). A control cohort of 25 patients were treated without the device (Control Group). All patients were monitored by the use of OKS, AKSS and FJS; beside that, the muscle function before and after the surgery was tested and a load distribution analysis was performed. The FU examinations were done after 6 weeks, 3 months, 6 months and 1 yr. All the patients finished the study and could be included.
Results
DLB group showed an improvement of 10% in the OKS compared to the Control Group, even if the preoperative measurements were lower (OKS DLB Group improve from 18 to 44, Control group from 26 to 40).
Also the AKSS shows an improvement around 10% in the DLB Group (38 to 97) compared to the Control Group (53 to 93); the knee score improved also in the same matter (DLB Group 32 to 91, Control Group 40 to 91).
Similar improvement in the FJS was also found in the DLB Group and in the Control Group. The muscles function testing showed a faster recovery of the muscle status and restore of the original functionality in the DLB Group. DLB Group patients recovered approx. 1/3 of the time faster than Control Group ones. The load distribution analysis shows a better load distribution with a more normal gait in the DLB Group.
Summary
In all PROMs the group treated by the support of the device showed a significant improvement and better clinical outcome, also the subjective patient satisfaction was higher in the DLB Group, where the proper ligament tension (aimed to functional stability) was achieved.
Conclusion
The use of sensory devices to secure proper balancing is justified by several studies. This study proves the efficacy of using a sensory device intraoperatively to measure the necessary ligament tension to achieve functional stability in a controlled single centre study.
