Related Experiment Video
Updated: Aug 7, 2026
In Vitro Application of a Wireless Sensor in Flexion-Extension Gap Balance of Unicompartmental Knee Arthroplasty
Published on: May 5, 2023
Clinical Outcomes of Functional Alignment Total Knee Arthroplasty using Intraoperative Sensors: A Prospective Cohort
Ankit Kumar Garg1, Shobhit2, Mohammed Saleh AlSaifi3
1Department of Orthopaedics, ITSA Hospitals, Raipur, Chhattisgarh, India.
Introduction:
Even with the present developments of total knee arthroplasty (TKA), a significant percentage of patients are still not satisfied after surgery, mostly because of the presence of pain and instability associated with poor balance of soft tissues. The philosophy of functional alignment has been proposed as a patient-specific philosophy of alignment with the intention to restore native knee kinematics, and intraoperative sensor technology has offered objective, real-time measurement of loads in the mediolateral compartments. There is little evidence on the integrated clinical outcome of functional alignment TKA with intraoperative sensors.
Purpose:
To compare clinical, functional, and biomechanical outcomes of functional alignment TKA with sensor guidance intraoperative in patients with primary knee osteoarthritis.
Materials And Methods:
A prospective cohort study with 50 patients undergoing primary unilateral TKA using the principles of functional alignment and intraoperative pressure-sensing technology was used. The intraoperative medial and lateral compartment loads were measured as pre- and post-balancing. Clinical outcomes, including knee society score (KSS), Visual Analog Scale (VAS), range of motion, radiographic alignment, complication rates, and patient satisfaction, were assessed pre-operatively and at 6 months post-operatively. Statistical analysis was performed using paired t-test and descriptive statistics, with P < 0.05 considered significant.
Findings:
Patients had poor knee performance (KSS-knee 42.6 ± 8.9; KSS-function 39.8 ± 9.4) and a high pain level (VAS 7.6 ± 1.1) pre-operatively. Significant mediolateral load imbalance at the start of the procedure (extension: 16.8 ± 6.2 lbs; 90° flexion: 10.9 ± 5.1 lbs) was significantly decreased after sensor-guided adjustments (extension: 2.5 ± 1.6 lbs; 90° flexion: 1.9 ± 1.4 lbs). KSS-knee (86.3 ± 7.4), KSS-function (82.1 ± 8.2), and VAS pain scales (1.8 ± 0.9) recorded significant improvements (P < 0.001) at 6 months post-operatively, and range of motion (118.6 ± 9.8) was improved (P < 0.001). In 88% of patients, acceptable limb positioning within the range of 3° of the neutral position was possible. The overall patient satisfaction was 92, and the rate of complication was low, and no revision was made.
Conclusion:
The TKA with intraoperative sensor technology functional alignment led to effective soft-tissue positioning, strong functional outcome, great pain management, and high patient satisfaction, which appears to be a promising personalized approach for TKA.