CLINICAL RESEARCH SUMMARY - Orthosensor

CLINICAL RESEARCH SUMMARY

OrthoSensor.com 2 VERASENSE

PROVEN RESULTS

A multicenter randomized controlled trial, a prospective 3-year multicenter study,

and additional research have proven the following clinical and economic benefits

from the use of VERASENSE in Sensor-Assisted TKA:

VERASENSE Sensor-Assisted Total Knee Arthroplasty offers

proven clinical and economic advantages for surgeons and hospitals.

A MULTI-CENTER RANDOMIZED CONTROLLED TRIAL PROVED

THAT – WITHOUT VERASENSE – TKAs ARE ONLY BALANCED

APPROXIMATELY 50% OF THE TIME [P.4]

98% OF BALANCED PATIENTS REPORT BEING SATISFIED TO VERY SATISFIED 3 YEARS POST-OP [P.5]

SIGNIFICANTLY HIGHER FORGOTTEN JOINT SCORES . COMPARED TO UNBALANCED PATIENTS [P.6]

DECREASED THE NEED FOR ALL-COMPONENT REVISION BY 88% FACILITATING IMPLANT COST MITIGATION [P. 9]

ALMOST75% LOWER RATE OF SOFT TISSUE BALANCE-RELATED EARLY REVISION TKA (<2 YEARS) COMPARED TO NATIONAL AVERAGES [P.10]

VERASENSE PATIENTS REQUIRE LESS PT AND 67% FEWER MUAs POST-OP [PP.6-8]

109


CLINICAL OUTCOMES

4 IsaSurgeon-Defined“BalancedKnee”FollowingTotalKneeArthroplastyReallyBalanced? Without VERASENSE, TKAs are only balanced approximately 50% of the time.

5 Patient-ReportedSatisfaction:3-YearMulticenterResults VERASENSE Sensor-Assisted TKA resulted in an increase to 98% patient-reported satisfaction at three years post-op.

6 RandomizedControlledTrial- DoesaBalancedTKAProducea MoreForgottenJoint? Patients with quantitatively balanced TKA have statistically significant higher forgotten joint scores than patients with unbalanced TKA based on 6-week, 6-month and 1-year outcomes data (p<0.05).

7 DecreasedRiskof90-DayPost-OpComplications(MUA) VERASENSE Sensor-Assisted TKA resulted in statistically significant reduction in MUA.

8 ImprovedPhysicalTherapyandShort-TermClinicalOutcomes VERASENSE patients have shown statistically significant improvement of PROMs and Physical Therapy performance.

ECONOMICS

9 CostMitigationDuringRevisionTKA Use of VERASENSE in revision TKA can potentially result in cost savings due to a decreased need for all-component revision.

10 PotentialforReducingIncidenceofEarlyRevisionTKA A VERASENSE multicenter study showed a significantly lower rate of early revision TKA compared to national averages.

SURGICAL TECHNIQUES

11 CanWeReally“Feel”aBalancedTotalKneeArthroplasty? Results from this study show that VERASENSE assists surgeons in decreasing the incidence of outliers in loading across the knee joint.

12 AccuracyofManualSurgeon-DefinedAssessmentofSoftTissueBalanceinTKAInComparisontoVERASENSESensor-GuidedMeasures–CanWeDetectAnUnbalancedKnee? Surgeon assessment is a poor predictor of knee compartmental loads and balance.

13 KneeBalancinginTotalKneeArthroplastyUsingtheVERASENSEArticularInsert.FindingsofaProspectiveCohortStudy Results have challenged traditional concepts of knee balancing.

THE PRESENTED VERASENSE™ DATA IS A COMPILATION OF RESEARCH PERFORMED THROUGH JANUARY 2018 EITHER IN COLLABORATION WITH OR INDEPENDENT FROM ORTHOSENSOR®, INC. THE CONTENT HEREIN IS TO BE USED FOR REFERENCE ONLY.

THERE ARE SURGEONS INVOLVED IN THIS RESEARCH WHO ARE PAID CONSULTANTS OF ORTHOSENSOR AND RECEIVE ROYALTY PAYMENTS FROM ORTHOSENSOR. ORTHOSENSOR HAS ALSO PROVIDED OR PROVIDES INSTITUTIONAL FUNDING IN SUPPORT OF THIS RESEARCH.

Investigations&KeyTakeaways


CLINICAL OUTCOMES

PURPOSE

Residual soft tissue imbalance in TKA may cause

instability, leading to greater pain and worse function.

This study compared blinded surgeons’ subjective, feel-

based evaluation of TKA balance to quantitative, intra-op

VERASENSE load measurements. It was hypothesized

that the surgeon-defined assessment is a poor predictor

of the actual state of soft tissue balance in TKA.

METHODS

• 170 primary TKA patients

• At the end of each case, surgeons were asked to

provide a manual assessment of balance in

extension and flexion

• Quantified balance data—blinded to the surgeon—

was then captured with VERASENSE

intraoperatively

• Mismatch between VERASENSE balance data and

surgeon-defined assessment were analyzed

(BALANCED = M/L load differential ≤ 15 lbf)

RESULTS

• By surgeon feel, all knees were deemed to be

acceptably balanced in both extension and flexion

• Blinded VERASENSE data showed only 51% (n=86)

of surgeon-guided TKAs were quantifiably balanced.

CONCLUSIONS

WITHOUT VERASENSE, TKAS ARE ONLY BALANCED APPROXIMATELY 50% OF THE TIME.

SURGEON-DEFINED ASSESSMENT CORRELATES POORLY WITH SENSORIZED FEEDBACK. QUANTITATIVE SENSOR DATA MAY PROVE USEFUL TO HELP ENSURE A BALANCED TKA.

Hospital for Joint DiseasesNYU LANGONE MEDICAL CENTER

IsaSurgeon-Defined“BalancedKnee” FollowingTotalKneeArthroplastyReallyBalanced?

BLINDED VERASENSEASSESSMENT OFSURGEON-GUIDED TKA

49% 51%

UNBALANCED

BALANCED

VERASENSE Multicenter Randomized Controlled Trial. Pending Publication. Data on file at OrthoSensor, Inc.

Statistics presented here represent study data analyzed as of January 24, 2018.


CLINICAL OUTCOMES

PatientReportedSatisfaction:3-YearMulticenterResults

PURPOSE

This sensor-assisted, multicenter study cohort was

prospectively assessed for concluding (3-year)

patient-reported outcomes. Scores were compared to

existing peer-reviewed publications reporting a similar

follow-up interval (2-3 years) to determine the impact

of consistent TKA soft tissue balance on patient

satisfaction.

METHODS

• 129 sensor-assisted patients (quantifiably balanced)

• 7-question survey administered (5-point Likert scale)

• Literature review conducted via PRISMA guidelines

RESULTS

• 98.3% of balanced, sensor-assisted patients

reported being “satisfied” to “very satisfied” at

3-years post-op1

• On average, 87% of patients reported being

“satisfied” to “very satisfied” in comparative

literature during the same follow-up interval2-9

CONCLUSION

THE VERASENSE GROUP EXHIBITED THE HIGHEST REPORTED SATISFACTION AMONG CONTEMPORARY TECHNOLOGIC AND MANUAL SURGICAL MODALITIES FOR THE SAME 3-YEAR POST-OP INTERVAL.

*Dr. Martin Roche participated in this research and is Founder and Chief Medical Officer of OrthoSensor, Inc.

Hospital

2-3 YEAR PATIENT REPORTED SATISFACTION:COMPARISON OF LITERATURE

60

75

70

65

95

90

85

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100MANUAL ROBOTICS PSI NAVIGATION

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VE

RA

SE

NS

E

98.3%

A Overall satisfaction with surgery

B Overall pain relief after the surgery

C Overall satisfaction with the function of knee

D I can do most things I thought I would be able to do after surgery

E My pain relief is as good as expected

F I am happy with the resultsof my surgery

G I would have the same surgeryagain for the same problem

ITEMIZED SATISFACTION QUESTION SCORES

SA

TIS

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SC

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E (

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E 1

-5)

4.0

5.0

4.8

4.6

4.4

4.2

A B C D E F G

SCORED ON LIKERT SCALE: 1 = LOWEST SCORE POSSIBLE “very dissatisfied” or “highly disagree” 5 = HIGHEST SCORE POSSIBLE “very satisfied” or “highly agree”

6. Spencer JM, Chauhan SK, Sloan K, Taylor A, Beaver RJ. Computer navigated versus conventional knee replacement. Bone Joint J. 2007; 89-B: 477-480.

7. Singisetti K, Muthumayandi K, Abual-Rub Z, Weir D. Navigation-assisted versus conventional total knee replacement: no difference in patient-reported outcomes measures (PROMs) at 1 and 2 years. Arch Orthop Trauma Surg. 2015; 135:1595-1601.

8. Liow MHL, Goh GSH, Wong MK, Chin PL, Tay DKJ, Y SJ. Robotic-assisted total knee arthroplasty may lead to improvement in quality-of-life measures: a 2-year follow-up of a prospective randomized trial. Knee Surg Sports Traumatol Arthrosc. 2017 Sep;25(9):2942-2951..

9. Martin A, von Strempel A. Two-year outcomes of computer tomography-based and computed tomography free navigation for total knee arthroplasties. Clin Orthop Relat Res. 2006; 49: 275-282.

1. 2-Year, 3-Year Clinical Outcomes, OrthoSensor Multicenter Evaluation. Pending Publication. Data on file at OrthoSensor, Inc.

2. Keudell AV, Sodha S, Collins J, Minas T, Fitz W, Gomoll AH. Patient satisfaction after primary total and unicompartmental knee arthroplasty: an age-dependent analysis. Knee. 2014; 21: 180-184.

3. Jacobs CA, Christensen CP, Karthikeyan T. Patient and intraoperative factoris influencing satisfaction two to five years after primary total knee arthroplasty. J Arthroplasty. 2014; 29: 1576-1579.

4. Nam D, Nunley RM, Berend KR, Lombardi AV, Barrack RL. The impact of custom cutting guides on patient satisfaction and residual symptoms following total knee arthroplasty. Knee. 2016; 23: 144-148.

5. Merle-Vincent F, Couris CM, Schott AM, Conrozier T, Piperno M, Mathieu P, Vignon E. /factors predicting patient satisfaction 2 years after total knee arthroplasty for osteoarthritis Joint Bone Spine. 2011; 78: 383-386.


CLINICAL OUTCOMES


PURPOSE

The Forgotten Joint Score-12 (FJS-12) is a PROM

evaluating the degree to which a patient is able to forget

about their joint following surgery. The aim of this study

was to measure post-operative joint awareness in patients

with and without a quantifiably balanced knee

following primary TKA.

METHODS

BLINDED MANUAL vs. UNBLINDED VERASENSE TKA BALANCING

• 267 patients thus far blindly-randomized into two

groups:

– Sensor-guided TKA with quantified, UNBLINDED

VERASENSE balancing

– Surgeon-guided TKA with BLINDED VERASENSE

load measurement

• Intra-op sensors utilized in all cases. BLINDED group

TKAs were balanced using standard, manual

techniques, with VERASENSE data collection blinded

to the surgeon.

RANDOMIZED GROUPS WERE POOLED POST-OP AND RE-STRATIFIED BY STATE OF SOFT TISSUE BALANCE:

– BALANCED = M/L load differential ≤ 15 lbf

through ROM

– UNBALANCED = any M/L load differential > 15 lbf

PRELIMINARY RESULTS

BALANCED PATIENTS REPORTED BEING LESS AWARE OF THEIR JOINT REPLACEMENT COMPARED TO UNBALANCED PATIENTS AT BOTH 6-WEEKS & 6-MONTHS POST-OP.

BALANCED patients showed:

– Fewer physical therapy sessions

– Fewer 90-day complications

CONCLUSIONS

PATIENTS WITH QUANTITATIVELY BALANCED TKA HAVE STATISTICALLY SIGNIFICANT HIGHER FORGOTTEN JOINT SCORES THAN PATIENTS WITH UNBALANCED TKA BASED ON 6-WEEK, 6-MONTH AND 1-YEAR OUTCOMES DATA (P<0.05).

FEWER PHYSICAL THERAPY VISITS AND FEWER COMPLICATIONS MAY TRANSLATE TO POTENTIAL COST SAVINGS.

RandomizedControlledTrial–DoesaBalancedTKA ProduceaMoreForgottenJoint?

PATIENT COHORTS

UNBALANCED BALANCEDTOTAL ENROLLED 267

6-WEEK DATA 220 92 128

6-MONTH DATA 149 59 90

0

10

20

30

40

50

60

FORGOTTEN JOINT SCORE

6-WEEK 6-MONTH

2433

4957

UNBALANCED

BALANCED

ME

AN

FJ

S

AVERAGE PT SESSIONS/PATIENT

MANIPULATION UNDERANESTHESIA

0

5

10

15

20

25

0

1

2

3

UNBALANCED BALANCED UNBALANCED BALANCED

2218

3

1

DA

YS

Golladay et al. Does a Balanced TKA Produce a More Forgotten Joint? ISTA/AAHKS 2017.

Longer-term follow-up data evaluating FJS-12 and additional PROMs along with the economic implications is ongoing.


CLINICAL OUTCOMES

PURPOSE

Manipulation under anesthesia (MUA) is a common

treatment for stiffness and arthrofibrosis post-TKA.

Studies show a higher degree of success when

treatment is performed earlier (<3 mo.) post-TKA2 ;

however, bundled payments models focusing on a

90-day episode of care may not provide reimbursement

within this timefreame.

MUA rates were compared for manual TKA versus

VERASENSE Sensor-Assisted TKA to determine if

consistent soft-tissue balance had any effect on the

rates of 90-day post-op complications.

METHODS

MUA RATE: VERASENSE VS. NON-SENSOR

• 252 sensor-assisted vs. 690 non-sensor

• All cases were performed by the same surgeon.

• There were no significant cohort demographic or

co-morbility differences.

• No difference in outcomes was seen based on

implant type, age or BMI.

RESULTS

VERASENSE: STATISTICALLY-SIGNIFICANT REDUCTION IN MUA

• 67% decrease in rate of MUA

• 62% of observed MUAs were within the 90-day

post-op interval

CONCLUSIONS

VERASENSE CAN MITIGATE 90-DAY POST-OP COMPLICATIONS THROUGH SOFT-TISSUE BALANCE.

A DECREASE IN MUAS SHOULD REDUCE OVERALL TKA READMISSIONS AND LESSEN THE COSTS AND RISKS CURRENTLY UNDER FOCUS THROUGH CMS’S COMPREHENSIVE JOINT REPLACEMENT PAYMENT PROGRAM.

DecreasedRiskof90-DayPost-OpComplications(MUA)THE USE OF ELECTRONIC SENSOR DEVICE TO AUGMENT LIGAMENT BALANCING LEADS TO A LOWER RATE OF ARTHROFIBROSIS AFTER TOTAL KNEE ARTHROPLASTY1

1. Geller JA, Lakra A, Murtaugh T, The Use of Electronic Sensor Device to Augment Ligament Balancing Leads to a Lower Rate of Arthrofibrosis After Total Knee Arthroplasty . J Arthroplasty. 2017 May;32(5):1502-1504

2. Fitzsimmons SE, Vazquez EA, Bronson MJ. How to Treat the Stiff Total Knee Arthtoplasty?: A Systematic Review. Clinical Orthopaedics and Related Research. 2010;468(4):1096-1106.

0

1

2

3

4

5

NON-SENSOR VERASENSE

4.9%

1.6%P=0.004O

VE

RA

LL

RA

TE

OF

MU

A


CLINICAL OUTCOMES

PURPOSE

The use of sensorized technology in TKA may help to

mitigate early soft-tissue complications and thereby

improve functional outcomes over manual techniques.

In order to evaluate the clinical efficacy of sensor-

assisted TKA at an early follow-up interval, 114 patients

were evaluated using patient reported outcomes

scores and clinical range of motion (ROM)

measurements.

METHODS

VERASENSE VS. MANUAL TKA BALANCING

• 57 consecutive sensor-assisted vs. 57 consecutive

manual

• All cases were performed by the same surgeon

with the same implant system.

• There were no significant cohort demographic or

co-morbidity differences.

RESULTS

VERASENSE: HIGHLY STATISTICALLY-SIGNIFICANT IMPROVEMENT ACROSS ALL OUTCOME MEASUREMENTS

• Faster improvement in PROMS (KSS, Oxford)

• Significantly higher Clinic ROM and improvement

in Clinic ROM from Pre-op

(P=0.002 AND P<0.001, RESPECTIVELY)

• More patients achieved active deep flexion

(>115 DEG.) during physical therapy

– 52% VERASENSE vs. 42% MANUAL

CONCLUSIONS

VERASENSE HAS SHOWN STATISTICALLY SIGNIFICANT IMPROVEMENT OF PROMS & PHYSICAL THERAPY PERFORMANCE.

AN INCREASE IN PHYSICAL THERAPY PERFORMANCE AND SHORT-TERM OUTCOMES DURING RECOVERY AND REHAB SHOULD TRANSLATE TO SHORTER TREATMENTS AND LOWER OVERALL COSTS IN THE COMPLETE TKA EPISODE OF CARE.

ImprovedPhysicalTherapyandShort-TermClinicalOutcomes

Breslauer L, Chow J. The use of intraoperative sensors significantly increases the patient-reported rate of improvement in primary total knee arthroplasty. Orthopedics. 2017 Jul 1;40(4):e648-e651.

KSS FUNCTION

PRE-OP 6-MONTHS

85

75

65

55

45

SC

OR

E

MANUAL

VERASENSE

IMPROVEMENTS PRE-OP TO 6 MONTHS

KSS Pain 29 36 0.001

KSS Function 23 27 <0.001

KSS Total 52 63 <0.001

Oxford 13 17 0.025

Clinic ROM 9 20 <0.001

MANUAL VERASENSE P-VALUE

°°


ECONOMICS

CostMitigationDuringRevisionTKACOST SAVINGS WHEN PLANNED TOTAL REVISION CHANGED TO PARTIAL REVISION TREATING THE ‘LOOKS GOOD, FEELS BAD’ KNEE BY DIAGNOSING SOFT TISSUE IMBALANCE

PURPOSE

Despite long-term success rates associated with total

knee arthroplasty (TKA), a large proportion of patients

continue to report dissatisfaction with their surgical out-

comes. Complications such as pain, stiffness, or

instability can reduce a patient’s quality of life and may

be attributed to soft-tissue imbalance. The cause of

imbalance related complications is often difficult to

diagnose, but if unresolved may lead to early total

revision surgery. However, these procedures are associated

with a higher risk of post-operative complications, elicit

longer rehabilitation regimes, and can become a

financial burden to the patient and healthcare provider.

Therefore, the purpose of this study was to determine

if the use of intraoperative sensors during revision TKA

led to a decreased need for all-component revision.

METHODS

58 REVISION TKA PROCEDURES

• 7 sites, 7 surgeons

• Patients reported with idiopathic pain, instability

and/or stiffness.

• Radiographs showed acceptable component

alignment with symmetrical joint gaps.

• Patients reporting pain had culture-negative

aspiration findings.

RESULTS

CHANGES TO PARTIAL REVISION (N=36)

• 10 tibia-only, 26 polyethylene exchange

ESTIMATED COST SAVINGS: $4,990 PER CASE

• I n 36 of 58 cases, expected total revisions changed

to partial revisions, which equates to

a theoretical implant cost savings of $179,640.

CONCLUSIONS

VERASENSE CAN FACILITATE IMPLANT COST MITIGATION DURING TKA REVISION1

POTENTIAL COST SAVINGS OF PARTIAL REVISIONS

• Shorter OR time, length of stay

• Less instrumentation, OR supplies

• Lower risk of complications (e.g., infection,

fracture)

• Shorter, easier post-op rehabilitation regime

• Less bone stock loss, internal constraint for patient


Leone W, et al. Using Sensors to Evaluate Revision TKA; Treating he “Looks Good; Feels Bad” Knee. EC Orthopaedics 3,5 (2016): 381-385

17

53

5

4170%

SCHEDULEDFOR TOTALREVISION

88%OF PLANNED

TOTALREVISIONSCHANGED TO

PARTIALREVISIONS (N=36)

PRE-OP PLAN PROCEDUREPOST-VERASENSE

REVISION TKAS USING VERASENSE

TOTAL r-TKA

PARTIAL r-TKA

AVERAGE REVISION TKA IMPLANT COST

TOTALREVISION

TIBIACOMPONENT POLYETHYLENE

$6,770* $2,880 $980

*REPRESENTS ⅔ OF MEDICARE DRG


ECONOMICS

PotentialforReducingIncidenceofEarlyRevisionTKA

1 Medicare Provider Analysis and Review File. 2013: Centers for Medicare & Medicaid Services Database – Primary and Revision TKA.

2 Bhandari M, Smith J, Miller L, et al. Clinical and economic burden of revision knee arthroplasty. Clin Med Insights Arthritis Musculoskelet Disord. 2012. 5: 89-94.

3 Lavernia C, Lee DJ, Hernandez VH. The increasing financial burden of knee revision surgery in the United States. Clin Orthop Relat Res. 2006; 446: 221-226.

4 Bozic K, Kurtz S, Lau E, et al. The epidemiology of revision total knee arthroplasty in the united states. Clin Orthop Relat Res. 2010. 468: 45-51.

5 Thiele K, Perka C, Matziolis G, Mayr HO, Sostheim M, Hube R. Current failure mechanisms after knee arthroplasty have changed: polyethylene wear is less common in revision surgery. J Bone Join Surg. 2015; 97(9): 715-720.

6 Lombardi AV, Berend KR, Adams JB. Why knee replacements fail in 2013: patient, surgeon, or implant? Bone Joint J. 2014;96-B(11 Supple A): 101-104.

7 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.

8 Sharkey PF, Lichstein PM, Shen C, et al. Why are total knee arthroplasties failing today—has anything changed after 10 years? J Arthroplasty. 2014;29(9):1774–1778.

9 OrthoSensor Multicenter Evaluation. Pending Publication. Data on file at OrthoSensor, Inc.

The annual healthcare financial burden of revision TKA is estimated at $2.7 BILLION based

on average hospital charges of 73 thousand dollars per case. Analysis of facility costs and

Medicare reimbursements shows over 90% OF HOSPITALS LOSE MONEY ON REVISION TKA,

with a loss of nearly $10,000 PER PROCEDURE .

VERASENSE multi-center study patients showed an almost 75% LOWER RATE OF REVISION TKA compared

to national averages. This reduction represents clinical and financial benefit to both patients and providers.

SENSOR-ASSISTED TKA: MULTICENTER STUDY TKA EARLY REVISION BURDEN (<2 YEARS, SOFT-TISSUE COMPLICATIONS)

FINANCIAL BURDEN OF TKA REVISIONS: 2013 MEDICARE PROVIDER ANALYSIS AND REVIEW FILE (MED PAR)1

* VERASENSE CANNOT PREVENT REVISION DUE TO INFECTION

HOSPITAL LOSSNET

PER TKA REVISION

$9,540CMSREIMBURSEMENT$19,134

COST$28,674

HOSPITALLOSS$9,540

HOSPITAL AVERAGECHARGES $73,000 2,3

90.3%REPORTED LOSSES

ON REVISION TKA PROCEDURES

OF HOSPITALS ANNUALFINANCIAL

FOR REVISION KNEE SURGERY

BILLION2

2.7$

BURDEN

0.7%*

VERASENSEMULTICENTER STUDY

APPROXIMATELY 2.6%OF TOTAL KNEE ARTHROPLASTIESRESULT IN EARLY REVISIONRELATED TO SOFT-TISSUE COMPLICATIONS4-8

(<2 YEARS)

2.6%*

UNITED STATESAVERAGE

12-13%REVISIONBURDENFOR TKA4,5

VERASENSE: ONLY 1 OF 143 PATIENTS (0.7%) REVISED WITHIN 2 YEARS9

Hospital


SURGICAL TECHNIQUES

PURPOSE

Intraoperative sensors were used in blinded (control)

and unblinded cohorts to compare the “feel” of an

experienced surgeon to sensor-generated data in

order to evaluate appropriate TKA balance through a

range of motion.

METHODS

• A total of 22 primary TKA patients, in 2 groups (12

manual, gap-balanced; 10 VERASENSE, sensor-

assisted), were evaluated for any differences in

mediolateral loading and soft-tissue release type

performed.

• Intraoperative sensors were used in both groups.

• The surgeon (30 years of experience) was blinded

to the sensor data in the manual group, and was able

to use the sensor data in the sensor-assisted group.

RESULTS

• The VERASENSE cohort exhibited lower overall

loading, in both the medial and lateral

compartments, than the manual group.

• Intercompartmental loading through the range of

motion was significantly more symmetrical in the

VERASENSE group than the manual group.

CONCLUSION

SENSOR-ASSISTED SURGERY PROVIDES OBJECTIVE DATA THAT MAY ASSIST SURGEONS IN DECREASING THE INCIDENCE OF OUTLIERS IN LOADING ACROSS THE KNEE JOINT.

CanWeReally“Feel”aBalancedTotalKneeArthroplasty?

Elmallah RK, Mistry JB, Cherian JJ, Chugato M, Bhave A, Roche MW, Mont MA. Can We Really “Feel” a Balanced Total Knee Arthroplasty? J Arthroplasty. 2016; 31: 5102-5105.

COMPARTMENTAL LOADING AVERAGESIN MANUAL AND VERASENSE COHORTS

MANUAL (BLINDED)

VERASENSE (UNBLINDED)

MEDIAL10

LATERAL10

LATERAL45

MEDIAL45

MEDIAL90

LATERAL90

90

80

70

60

50

40

30

20

10

0

DEGREES OF FLEXIONL

OA

DIN

G (

LB

F.)

CHARACTERISTIC COMPARTMENTAL LOADING EXAMPLES IN MANUAL AND VERASENSE COHORTS

COMPARISON OF COMPARTMENT LOAD AT VARIOUS DEGREES IN RANGE OF MOTION IN MEDIAL AND LATERAL COMPARTMENTS

DEGREES OF FLEXION VERASENSE COHORT MEAN (RANGE) (SD)

MANUAL COHORT MEAN (RANGE) (SD) P VALUE

MEDIAL COMPARTMENT 10° 45° 90°

22.8 (16-44) (8) 23.1 (9-38) (8) 20.4 (7-38) (8)

79.3 (12-228) (62) 77.2 (6-177) (51) 55.4 (4-159) (48)

.0108

.0035

.0326

LATERAL COMPARTMENT 10° 45° 90°

17.2 (0-38) (10) 13.3 (4-25) (7) 16.1 (7-38) (8)

27.6 (0-102) (37) 31 .3 (0-99) (38) 28.4 (0-73) (29)

.39

.15

.21

SD, STANDARD DEVIATION

MANUAL (BLINDED)

VERASENSE (UNBLINDED)


SURGICAL TECHNIQUES

PURPOSE

The accuracy of surgeon-defined assessment (SDA) of

soft tissue balance in TKA was compared to sensor-

guided assessment with VERASENSE to assess the ability

of sensor data in guiding the surgeon to achieve targeted

balance. The hypothesis is that arthroplasty-trained SDA

is a poor predictor of the state of soft tissue balance

in TKA.

METHODS

• 238 single-surgeon, sensor-assisted TKAs

– 159 varus (mean -6.5°)

– 67 valgus (mean 7.3°)

– 12 neutral

• Conventional intramedullary guides, same implant

system for all TKAs

• Standard trial surgical assessment and prediction

of knee balance status, THEN corresponding

VERASENSE trial inserted to quantify balance

(“balanced” = M/L difference ≤15 lbf)

RESULTS

ACCURACY OF SURGEON-DEFINED ASSESSMENT OF BALANCE – 62%

– Correct when predicting “balanced” – 61%

– Correct when predicting “unbalanced” – 65%

CHANGE OF SURGICAL PLAN IN 38% (N=90) OF CASES

– 29% (n=68) needed balancing

– 9% (n=22) prevented unnecessary balancing

CONCLUSIONS

SURGEON ASSESSMENT IS A POOR PREDICTOR OF KNEE COMPARTMENTAL LOADS AND BALANCE

WITH SURGICAL TECHNIQUES THAT AIM TO IMPROVE BALANCE, IMPROVEMENTS IN QUANTIFICATION AND VALIDATION OF KNEE BALANCE ARE REQUIRED.

AccuracyofManualSurgeon-DefinedAssessmentofSoftTissueBalanceinTKAInComparisontoVERASENSESensor-GuidedMeasures–CanWeDetectanUnbalancedKnee?

TOTALPATIENTS

238

CHANGE OFSURGICAL

PLAN38%

SURGEON CLAIMSBALANCE

176

VERASENSECONFIRMS

108

VERASENSECONTRADICTS

68

VERASENSECONTRADICTS

22

VERASENSECONFIRMS

40

REQUIRING FURTHERADJUSTMENTS

29%

PREVENTINGADJUSTMENTS

9%

POSITIVEPREDICTIVE VALUE

61%

NEGATIVEPREDICTIVE VALUE

65%

SURGEON CLAIMSUNBALANCE

62

MacDessi S. Accuracy of manual surgeon defined assessment of soft tissue balance in TKA In comparison to VERASENSE sensor-guided measures – can we detect an unbalanced knee? AOA 2017.


SURGICAL TECHNIQUES

PURPOSE

The aim of this prospective study was to define the

surgical techniques required to achieve optimal knee

balance during VERASENSE Sensor–Assisted TKA.

METHODS

• 238 single-surgeon, sensor-assisted TKAs

– 159 varus (mean -6.5°) – 67 valgus (mean 7.3°) – 12 neutral

• Conventional intramedullary guides, same implant

system for all TKAs

• Surgeon performed standard surgical treatment,

aimed for neutral mechanical alignment, and then

balanced the knee as per prior published

VERASENSE protocols

RESULTS

CONCLUSIONS

RESULTS HAVE CHALLENGED TRADITIONAL CONCEPTS OF KNEE BALANCING.

• Bone adjustments required to alter soft tissue

tensions in ¼ of cases

• Counterintuitive soft tissue releases not always

on the same side as the disease pattern

• Traditional soft tissue releases may have less

impact than thought

– ITB laterally

– Semimembranosus / PM Capsule medially

CONTINUED REFINEMENT OF TECHNIQUES TO OPTIMIZE BALANCE IS REQUIRED TO DETERMINE ASSOCIATION WITH NEWER ALIGNMENT STRATEGIES AND CLINICAL OUTCOMES.

KneeBalancinginTotalKneeArthroplastyUsingtheVERASENSEArticularInsert.FindingsofaProspectiveCohortStudy.

OVERALL65% Required Balance Adjustment

BONE ADJUSTMENTS

SOFT TISSUE RELEASE ONLYNO ADJUSTMENT

27%

38%

35%

MEDIAL

LATERALBILATERAL

89%

8%

3%

VARUS KNEE RELEASES65% Required Balancing

42% 54%

VALGUS KNEE RELEASES75% Required Balancing

4%

VARUS KNEE SOFT TISSUE RELEASES

VALGUS KNEE SOFT TISSUE RELEASES

MCL PIE CRUST

MCL & PM

PM CAPSULE

ARCUATE

ARCUATE & POPLITEUS

ARCUATE

ITB

POPLITEUS / LCL

MCL PIE CRUST

0 5 10 15 20 25

0 10 20 30 40 50 60

VARUS KNEE SOFT TISSUE RELEASES

VALGUS KNEE SOFT TISSUE RELEASES

MCL PIE CRUST

MCL & PM

PM CAPSULE

ARCUATE

ARCUATE & POPLITEUS

ARCUATE

ITB

POPLITEUS / LCL

MCL PIE CRUST

0 5 10 15 20 25

0 10 20 30 40 50 60

MacDessi S. New Concepts in Knee Balancing in Total Knee Arthroplasty Using the Verasense Articular Insert. Findings of a Prospective Cohort Study. COKS/AKS 2017.


Notes


Notes

www.OrthoSensor.com

Tel +1 888.75.ORTHO (+1 888.756.7846) | Tel +1 954.577.7770 | Fax +1 954.337.9222

OrthoSensor, Inc. | 1855 Griffin Road, Suite A-310 | Dania Beach, Florida 33004 USA

OS-VS-18-5148 Rev0

Documents

CLINICAL RESEARCH SUMMARY - Orthosensor