A leader in sensor-assisted technologies, South Florida based OrthoSensor, Inc. develops and commercializes an intelligent orthopaedic device and data services that provide quantitative feedback to surgeons and hospitals
VERASENSE SENSOR-ASSISTED TECHNOLOGY NOW APPROVED FOR USE
WITH ZIMMER BIOMET PERSONA® KNEE SYSTEM
VERASENSE enables surgeons to improve knee balance and customize implant position during surgery by using intraoperative sensor data
DANIA BEACH, Fla., June 11, 2018 — OrthoSensor, Inc., a leader in sensor-assisted technology for total knee replacement (TKR), today announced it has received 510(K) clearance from the U.S. Food and Drug Administration (FDA) for its VERASENSE* Sensor-Assisted Technology (VERASENSE) to be used with Zimmer Biomet’s Persona Knee System for total knee replacement.
VERASENSE harnesses the latest innovations in sensors and wireless communications for primary and revision total knee replacement (TKR) during surgery, with the goals of improving patient outcomes and satisfaction.
Said Ivan Delevic, President and Chief Executive Officer of OrthoSensor, Inc.: “Receiving FDA clearance for VERASENSE use with the Zimmer Biomet Persona Knee System, augments this outstanding implant and instrumentation, securing a better-balanced knee after surgery. The VERASENSE device brings real-time, quantified soft tissue balance data to our surgeons. This evidenced-based data regarding soft tissue balance works with systems such as Persona so that surgeons can make objective assessments intraoperatively, resulting in better clinical outcomes for patients.”
Earlier this year, OrthoSensor received clearance to use VERASENSE with the Persona Knee System in Australia. Dr. Lachlan Host from Bathurst Private Hospital in Australia successfully used VERASENSE for Persona Knee System for the first time. Dr. Host said, “Using VERASENSE has completely changed my joint arthroplasty practice. Since using VERASENSE, I have found patients have consistently improved range of motion and have had less focal pain. I now know, irrefutably, that I am achieving improved patient outcomes.”
Historically, roughly one in every five TKR patients (~20%) is dissatisfied with the results of their surgery. Common patient complaints include persistent pain, instability, stiffness, and loss in range of motion.1-3 Before VERASENSE; surgeons generally relied on their “best judgment” in determining what “felt” like a balanced knee.
The subjectivity of total knee replacement, coupled with improper soft tissue balance and implant position, may result in premature implant failure and the need for revision surgery in the future.6-10
In a prospective multi-center study, VERASENSE use was proven to reduce post-operative pain, accelerate patient activity levels, improve functional outcomes, and increase patient satisfaction scores with high statistical significance.2-5 In fact, 98 percent of patients whose knees were balanced using VERASENSE reported they were satisfied to very satisfied at three years post-op.2-5 These proven results point to improved joint balance being the key to higher TKR satisfaction.
About OrthoSensor, Inc.
OrthoSensor, Inc., a leader in Sensor-Assisted Total Knee Arthroplasty, develops and commercializes intelligent orthopedic devices and data services that provide quantitative feedback to surgeons and hospitals. The company’s intelligent orthopaedic devices utilize advanced proprietary sensor and communications technologies, coupled with the company’s innovative software products, to facilitate evidence-based decisions in orthopaedic surgery – with the goal of improving patient outcomes and potentially reducing the cost of treating musculoskeletal disease.
OrthoSensor® VERASENSE, and OrthoLogIQ® are trademarks of OrthoSensor, Inc.
Persona® is a trademark of Zimmer Biomet.
1. Bourne RB, Chesworth B, Davis A, Mohamed N, Charron K. Comparing patient outcomes after THA and TKA: is there a difference? Clin Orthop Relat Res. 2010; 468: 542-546.
2. Gustke K, Golladay G, Jerry G, Roche MW, Elson LC, Anderson CR. Increased Patient Satisfaction After Total Knee Replacement Using Sensor-Guided Technology. Bone Joint J. 2014 Oct;96-B(10):1333- 8.
3. Gustke KA, Golladay GJ, Roche M, Elson L, Anderson C. Primary TKA patients with Quantifiably Balanced Soft-Tissue Achieve Significant Clinical Gains Sooner than Unbalanced Patients. Adv Orthop. 2014: 628695.
4. Gustke KA, Golladay GJ, Roche MW, Elson LC, Anderson CR. A new method for defining balance: promising short-term clinical outcomes of sensor-guided TKA. J Arthroplasty 2014;29:955–960.
5. 2-Year, 3-Year Clinical Outcomes, OrthoSensor Multicenter Evaluation. Pending Publication. Data on file at OrthoSensor, Inc.
6. Parratte S, Pagnano MW. Instability after total knee arthroplasty. J Bone Joint Surg Am 2008; 90: 184–94.
7. Bozic et al. The epidemiology of revision total knee arthroplasty in the United States. Clin Orthop Relat Res.2010; 468(1):45–51.
8. Lombardi AV Jr1, Berend KR1, Adams JB1. Why knee replacements fail in 2013: patient, surgeon, or implant? Bone Joint J. 2014 Nov;96-B(11 Supple A):101-4.
9. Schroer WC, Berend KR, Lombardi AV, et al. Why are total knees failing today? Etiology of total knee revision in 2010 and 2011. J Arthroplasty 2013;28(8 Suppl):116–119.
10. Rodriguez-Merchan, EC. Instability Following Total Knee Arthroplasty. HSSJ. Oct 2011; 7(3): 273–278.
Citation: Elmallah R, Mistry J, Cherian J, Chughati M, Bhave A, Roche M, Mont M. Can we really “feel” a balanced total knee arthroplasty. J Arthroplasty 31 (2016). S102-S105.
Approximately 20% of patients report dissatisfaction after undergoing total knee arthroplasty (TKA).1 Patients may experience complications with knee stiffness, pain and/or instability, which may result from soft tissue imbalance.2,3 Determining whether a knee is “balanced” is based on the surgeon’s subjective judgment, operative experience and skill.
The introduction of newer technologies has allowed for objective measurements of soft tissue balancing throughout knee range of motion. A wireless, intraoperative sensor tibial insert has been designed to measure intercompartmental loads of the knee to provide quantitative feedback of the medial and lateral compartments during TKA trialing.4 When using the device, the surgeon will perform the TKA in the typical manner and insert the sensor into the knee only after they believe it is balanced to guide additional balancing, cuts, and releases. Past research has demonstrated that adequate soft tissue balancing contributed to improved TKA outcomes.4,5
This study compared the use of sensor technology to the 30-year surgeon experience regarding
(1) compartment loads,
(2) soft tissue releases and
(3) component orientations.
Twenty-two patients undergoing TKAs were evaluated prospectively in a pilot series and divided into two cohorts: sensor-guided balancing (n = 10), or manual gap balancing (n = 12). Both groups were asked to use the sensor tibial insert trial to evaluate congruity and contact loads before applying cement to the final implant. In the manual gaping cohort, the surgeon was blinded and unaware of the values to eliminate bias from surgery performance. In the sensor cohort, the surgeon was unblinded and placed the sensor into the knee after they believed it was balanced; then used the data to guide further soft-tissue balancing and component position. Load measurements were taken at 10°, 45° and 90° (Figure 1).
Figure 1: Blinded vs Unblinded
The sensor cohort had lower medial and lateral compartment loading, lower mean differences in intercompartment loading, and performed more soft tissue releases compared to the manual gap cohort. The additional 10 releases were performed as a result of sensor evaluation, which would not have been done otherwise during manual-gap balancing. Manual balancing relies on the surgeon’s subjective assessments and may result in uneven loads, which may be associated with poor patient outcomes. The results from this study show sensor-balanced TKAs provide objective feedback to perform more soft tissue releases that may potentially improve knee balancing and component position.
So now that we know from this work, as well as others1,4,5, that the sensor can help us obtain more balanced knees, we need to know whether these “balanced” knees by sensor-aided technology perform better. It would appear that this is self- evident, but we still need proof that more precisely done knees function more optimally clinically. An ongoing prospective randomized controlled trial presently being performed may help answer these questions.
Dr. Michael Mont is a paid consultant to OrthoSensor, Inc.
1. Gustke KA, Golladay GJ, Roche MW, et al. Increased satisfaction after total knee replacement using sensor-guided technology. Bone Joint J 2014;96-B(10):1333.
2. Sharkey PF, Hozack WJ, Rothman RH, et al. Insall Award paper. Why are total knee arthroplasties failing today? Clin Orthop Relat Res 2002;(404):7.
3. Wylde V, Hewlett S, Learmonth ID, et al. Persistent pain after joint replacement: prevalence, sensory qualities, and postoperative determinants. Pain 2011;152(3):566.
4. Gustke KA, Golladay GJ, Roche MW, et al. A new method for defining balance: promising short-term clinical outcomes of sensor-guided TKA. J Arthroplasty 2014;29(5):955.
5. Gustke KA, Golladay GJ, Roche MW, et al. Primary TKA patients with quantifiably balanced soft tissue achieve significant clinical gains sooner than unbalanced patients. Adv Orthopedics 2014;628695:2014.
Despite long-term survivorship of contemporary total knee arthroplasty (TKA) components, 1 in 5 recipients of TKA are dissatisfied with their outcomes. Possible reasons for dissatisfaction include limited function or higher pain levels. There is also a discordance between patient expectations and achievable activity levels (Noble ref). One reason for dissatisfaction is a mismatch between patient expectations and achievable activity levels.1 Instability and stiffness significantly affect activity levels and symptoms, and as a result, account for a significant proportion of early revision surgeries.2
Activities such as low-impact sports require a stable, well-balanced knee. However, techniques used to assess and achieve a balanced TKA have been simple and subjective, with no standard definition of what constitutes a “balanced” knee. The surgeon attempts to create equally spaced rectangular gaps between the tibia and the femur at 0 and 90 degrees of flexion and then tests the stability of the knee using trial implants. These methods are not reproducible or quantifiable in a reliable way, which likely accounts for a significant portion of dissatisfied patients and early revisions. Recently, sensors have been developed to quantify soft tissue tension and balance in the knee, and to attempt to establish an objective definition of balance.
Multicenter Study Results
A three-year prospective multicenter study was conducted to clinically assess patients who had received Sensor-Assisted TKA. Surgeons from 8 centers in the United States performed TKA utilizing the same implant model, with technique according to their respective training and experience. After the surgeon judged that the knee was balanced, a nanosensor trial was placed into the joint and final loading values were captured for the medial and lateral compartments at 10, 45 and 90 degrees of flexion. Analysis of early patient reported outcomes measures (PROMs) at six months revealed that patients exhibiting a mediolateral loading differential less than 15 lbf. reported statistically significantly less pain, higher activity levels, and greater function than those with differentials beyond the 15 lbf. threshold.3 Regression analysis including other potential contributing variables (preoperative function, range of motion, age, demographic or physical variables, etc.) revealed that the only significant contributing variable associated with better outcomes is the state of soft tissue balance (< 15 lbf. mediolateral load differential at all three measured flexion angles).
The same trends were reported at one and two years with the same group of patients and the same PROMs.4 Further, balanced patients were found to score significantly higher on a seven-item satisfaction survey using a five-point Likert scale at 1 year than the group of unbalanced patients, with an overall satisfaction rate of >97%, which is higher than any other published TKA study reporting on patient satisfaction to date.5
The results from this multicenter prospective study are unique, representing the first published attempts at quantifying a definition of soft tissue balance during TKA, through a range of motion. Since the time of publication of these results, independently conducted evaluations of this definition of balance have been confirmatory.6,7 Taken together, these studies demonstrate that that the clinical efficacy of TKA is highly dependent on proper soft tissue balance, defined as a mediolateral load differential of <15lbf.