Kinetic Sensors for Ligament Balance and Kinematic Evaluation in Anatomic Bi-Cruciate Stabilized Total Knee Arthroplasty

Abstract

Sensor technology was introduced to intraoperatively analyse the differential pressure between the medial and lateral compartments of the knee during primary TKA using a sensor to assess if further balancing procedures are needed to achieve a “balanced” knee. The prognostic role of epidemiological and radiological parameters was also analysed. A consecutive series of 21 patients with primary knee osteoarthritis were enrolled and programmed for TKA in our unit between 1 September 2020 and 31 March 2021. The VERASENSE Knee System (OrthoSensor Inc., Dania Beach, FL, USA) has been proposed as an instrument that quantifies the differential pressure between the compartments of the knee intraoperatively throughout the full range of motion during primary TKA, designed with a J-curve anatomical femoral design and a PS “medially congruent” polyethylene insert. Thirteen patients (61.90%) showed a “balanced” knee, and eight patients (38.10%) showed an intra-operative “unbalanced” knee and required additional procedures. A total of 13 additional balancing procedures were performed. At the end of surgical knee procedures, a quantitatively balanced knee was obtained in all patients. In addition, a correlation was found between the compartment pressure of phase I and phase II at 10° of flexion and higher absolute pressures were found in the medial compartment than in the lateral compartment in each ROM degree investigated. Moreover, those pressure values showed a trend to decrease with the increase in flexion degrees in both compartments. The “Kinetic Tracking” function displays the knee’s dynamic motion through the full ROM to evaluate joint kinetics. The obtained kinetic traces reproduced the knee’s medial pivot and femoral rollback, mimicking natural knee biomechanics. Moreover, we reported a statistically significant correlation between the need for soft tissue or bone resection rebalancing and severity of the initial coronal deformity (>10°) and a preoperative JLCA value >2°. The use of quantitative sensor-guided pressure evaluation during TKA leads to a more reproducible “balanced” knee. The surgeon, evaluating radiological parameters before surgery, may anticipate difficulties in knee balance and require those devices to achieve the desired result objectively.

Sensor-guided gap balance versus manual gap balance in primary total knee arthroplasty: a meta-analysis

“…The quantitative balance has been defined as a mediolateral intercompartmental loading difference of fewer than 15 pounds [ 14 ]. Using this technology, the surgeon receives real-time feedback of the loading in the knee and can adjust any imbalance with soft tissue corrections or additional bony resections [ 38 , 39 ].…”

No Significant Differences in Clinical and Radiographic Outcomes between PCL Retained or Sacrificed Kinematic Aligned Medial Pivot Total Knee Arthroplasty in Varus Knee

“…The inclusion criteria were patients over 60 years of age with primary end-stage osteoarthritis (grades three and four of the Kellgren-Lawrence classification) [ 31 ] who underwent primary TKA according to KA-calibrated criteria [ 21 ] using a medial congruent (MC) TKA (Persona MC, by Zimmer Biomet) [ 7 ] with a minimum follow-up of two years. Patients under 60 years of age with secondary knee osteoarthritis that was not severe (grade one or two of the Kellgren-Lawrence classification) underwent primary TKA according to the mechanical alignment criteria, while those with non-medial congruent implants, valgus knee, follow-up of less than two years, previous osteotomies or ligament reconstructions, or previous severe traumatic surgical treatment around the knee were excluded from the present study.…”

“…Among them, sociodemographic, preoperative, intraoperative, and postoperative factors should be considered [ 5 , 6 ]. Several materials and surgical techniques have been introduced into clinical practice to improve patient satisfaction and long-term clinical and functional outcomes [ 7 , 8 , 9 , 10 , 11 ].…”

Sensors and digital medicine in orthopaedic surgery

“…[52] Most common is the use of sensors for intraoperative measurements in total joint arthroplasty. [52][53][54][55] Very few indwelling options are available. [49,56] One device has been designed for allowing pressure monitoring in total knee arthroplasty to determine imbalances of force.…”