Conventional vs. Sensor Guided Soft Tissue Balancing in TKA RCT

Hamilton Health Sciences (HHS)

Status: Completed

Conditions: Total Knee Arthroplasty

Treatments: Procedure: Standard Soft Tissue Balancing; Procedure: Sensor Guided Soft Tissue Balancing

Study type: Interventional

Funder types: Other

Identifiers

NCT02976428

HAGRP01

Details and patient eligibility

About

To ensure a successful outcome after total knee replacement (TKR) soft tissue balance and proper implant position are very important during the surgical procedure. Soft tissues are structures in the knee including ligaments, muscles, tendons, and menisci that stabilize and cushion the knee joint. Lack of proper soft tissue balance or imprecise implant positioning may result in knee stiffness, pain, instability and limited range of motion (ROM). This may result in implant failure and the need for revision surgery. As part of standard practice orthopedic surgeons use a manual knee balancer device to help guide soft tissue balancing to achieve optimal knee balance. New sensor-assisted technology can provide surgeons with measurable information to help achieve soft tissue balancing, providing surgeons with immediate visual feedback during the surgery. This feedback, transmitted wirelessly by the sensor, gives surgeons electronic information on soft tissue balance and implant position.The purpose of this study is to determine if a sensor guided soft tissue balancing device (Verasense) is more effective at balancing the knee during surgery as compared to standard soft tissue balancing performed with a manual balancer device.

Full description

The study is that of a prospective double-blind randomized controlled trial of patients presenting for elective primary TKR to compare the outcomes of TKR using conventional soft tissue balancing with a tensiometer device versus augmenting the soft tissue balancing with the OrthoSensor VerasenseTM sensor device. The primary outcome will be rate of unbalanced TKRs based on the quantitative Verasense definition of a well balanced knee defined as a mediolateral intercompartmental loading difference of ≤15 pounds through ROM. Secondary outcomes include differences in clinical outcome scores and patient satisfaction among sensor guided cases and controls.

Patients will be randomized to receive TKR with the Triathlon total knee system (Stryker) in the case and control group according to: (1) control group with standard balancing techniques used and sensor data obtained in blinded fashion and not used to balance the TKR implant, (2) experimental case group with sensor guided balancing where sensor data is used to balance the TKR within defined parameters.

Enrollment: 184 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients scheduled to undergo elective primary unilateral TKR for a diagnosis of osteoarthritis to be performed at the study site by the primary investigators
• Willingness and ability to give informed consent.

Exclusion criteria

• Inflammatory arthropathy
• Ligament insufficiencies
• Contraindications to posterior cruciate retaining TKR including: deformity >15 degrees or fixed-flexion contracture >15 degrees
• Previous high tibial osteotomy
• Scheduled to undergo sequential bilateral TKR under one anesthetic
• Scheduled to undergo revision TKR surgery
• Neuromuscular disorder limiting mobility or ability to comply with physiotherapy
• Previous recurrent deep knee infection
• Major bone loss requiring structural bone graft or augmented components
• Functionally limiting peripheral vascular disease
• Patients receiving associated worker's compensation benefits (WSIB)
• Ethanol/drug abuse/psychiatric disorder
• Inability or unwillingness to give written informed consent to participate

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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184 participants in 2 patient groups

Standard Soft Tissue Balancing

Active Comparator group

Description:

In the control group where the sensor device is not used in optimization of knee balance and alignment, definitive implants will be cemented in place and the sensor trial inserted using a thickness based on prior standard bearing insert trialing. Peak load data will be captured intraoperatively through full ROM. Custom shims will be affixed to the sensor to replicate thickness of the standard trial. The knee will then be cycled and loads recorded in the medial and lateral compartments at 10, 45 and 90 degrees of flexion. The surgeon will be blinded to the sensor output and the system will be located outside of their visual field.

Treatment:

Procedure: Standard Soft Tissue Balancing

Sensor Guided Soft Tissue Balancing

Experimental group

Description:

In the experimental group where the sensor device is used to optimize balance and alignment, the sensor trial will be inserted and tibial baseplate rotated until medial and lateral femoral contact points are parallel on the sensor output. Quantitative balance is defined as a mediolateral intercompartmental loading difference of ≤15 pounds. Flexion balance is achieved when femoral contact point position is within the midposterior third of the tibial insert and intercompartmental loads are balanced. Loads in the medial and lateral compartments are recorded at 10, 45 and 90 degrees. If compartment loads differ by \>15 lbs between compartments, unbalanced, further soft tissue release/bone resection will be done to achieve a side to side compartment pressure difference of \<15 lbs through ROM.

Treatment:

Procedure: Sensor Guided Soft Tissue Balancing