conclusion - aacpdm · koshino z initial post predicted kz final koshino z pre conclusions •...

AACPDM IC#21 DFEO+PTA 40

Conclusion

• The hamstrings do not need to be lengthenedconcomitantly with DFEO/PTA

PATELLAR POSITION POST DFEO+PTA

Tom Novacheck, MD

Does Patellar Position Change With Growth After Patellar Tendon Advancement In Children With

Cerebral Palsy?

Claire F Beimesch, MD; Jean Stout, PT;MS Ranjit Varghese, MD; Mike

Schwartz, PhD; Tom F Novacheck, MD

Purpose: What happens to patellar position with further growth?

• For patients who have PTA (with or withoutDFEO) prior to skeletal maturity,

– Is patellar position stable with growth?

– Does patella alta recur?

– Is patellar baja progressive?


Materials and Methods

• IRB approval

• Patients with CP and crouch gait

• Underwent either DFEO + PTA, or PTA

• Years 1999‐2010

• Minimum of three years of follow‐up and 3years of growth remaining

• Radiographs at pre‐op, 3 months post‐op, andyearly intervals until skeletal maturity

Measurements

• Koshino Index (KI)

• Tibial‐Physeal Angle (TPA)

• Complications

• Skeletal Maturity (physeal closure)

Koshino Index (KI)

• Measure of patellar position

• Valid for various angles of knee flexion

• Midpoint of femoral and tibialphysis and patellar long axis

• Ratio of the patellar‐tibial andthe femoral‐tibial distance

• Measured against standard “Z‐score” for amount of kneeflexion (KZ)

Results

• 38 patients, 67 knees

• 40 knees underwent DFEO+PTA

• Age at presentation 11.5 ± 1.5 yrs

• Average follow‐up 4.4 ± 1.5 yrs

• p < 0.05 was considered statistically significant


ResultsKoshino Index (KI) & Koshino Z‐score (KZ)

Preop KI Preop KZ 3 month postop KZ

KZ final

1.3 0.51 ‐3.3 ‐2.9

upper range of normal

upper range of normal

patella baja

Maintained over‐

correction

Patellar Position over Time From Surgery

Stepwise Linear Regression Analysis

• to provide a predictive model to assess finalpatellar position based on previous KZmeasurements

• Predictors evaluated– Age at Surgery– Time from Surgery– Surgery Type– Preoperative KZ– Initial KZ at 3 month follow up

• Dependent Variable– Final KZ


Predictive

– Preoperative KZ

– Initial postop KZ

Not predictive

– Surgery Type

– Age at Surgery

– Time from Surgery



Example:1. preoperative KZ = 0.51

2. initial postoperative KZ = ‐3.3

3. predicts a final KZ = ‐2.9

Koshino Z Initial Post

Predicted KZ Final

Koshino Z pre

Conclusions

• Correction of knee extensor insufficiencyrequires overcorrection of patellar position

• When PTA is performed prior to skeletalmaturity, correction of patellar position ismaintained or rebounds slightly over time anddoes not appear to be progressive.

• Pre‐op KZ and 3 month postop KZ arepredictive of final follow up KZ

Long‐Term Effects of Patellar Tendon Advancement (PTA) on Proximal

Tibial Growth

Jean Stout, PT, MS; Claire F. Beimesch, MD; Ranjit Varghese, MD; Michael Schwartz, PhD;

Tom F Novacheck, MD

PTA Prior to Skeletal Maturity: How is Proximal Tibial Growth Influenced?

Alteration in the loading pattern on the proximal tibia is possible through the end of growth

Patellar Position (KoshinoIndex)

Knee Flexion Angle

Koshino Index changes following Distal Femoral Extension Osteotomy (DFEO) + Patellar Tendon Advancement (PTA)


Tibial ‐ Physeal Angle (TPA)

Physeal Line

Tibial Line

Tibial Physeal Angle

Mean TPA Typical Child 95° +/‐ 3.5°

Purpose: 1) Examine the long term effects of PTA on the growth of theproximal tibia (TPA change)

2) Assess whether changes in TPA are associated with clinical recurvatum

Preoperative Postoperative

• IRB approval• Patients with CP and crouch gait• Underwent either DFEO + PTA, or PTA• Years 1999‐2010• Minimum of three years of follow‐up & at least 3 years of growth remaining

• Radiographs at pre‐op, 3 months post‐op, andyearly intervals until skeletal maturity

• Clinical documentation review• Gait studies review when available to assess for evidence of recurvatum

Methods

Variable Value

N 38 (67 knees)

M:F 23:15

Age at Surgery 11.5 (±1.5) years

Average X‐Ray Follow‐up 4.4 (±1.5) years

Bilateral Surgery 76%

Concomitant DFEO 61%

Pre‐Surgery TPA 94°(±4°)

Results

Mean TPA Typical Child 95° +/‐ 3.5°

Mean TPA in CP cohort 94° +/‐ 4°

Tibial Physeal Angle Measurements


Results: TPA generally stable over time(with a few exceptions circled in red)

Surgery = Tim

e Zero

Typical TPA

TPA vs. Time from Surgery

Surgery = Tim

e Zero

Typical TPA

TPA vs. Time from Surgery (by surgery type)

PTA Only DFEO+PTA

Results

Does the combination of DFEO+PTA have more

impact on TPA than PTA alone?

ΔTPA= 31 ‐ 2.8 * age at surgery‐ 6.7 * time from surgery + 6.6 * amount of correction + .61 * (age at surgery x time from surgery) + .59 * (age at surgery x amount of correction)‐ .27 * (time from surgery x amount of correction)

Stepwise Linear Regression: Case Example

Age at Surgery Time since surgery Amount of correction(years) (years) (Koshino change)

In this case example, age 10 at surgery, 5 years since surgery, and Koshino Index change of 4, TPA is predicted to decrease 7.5°

Predicted TPA

change(degrees)

Interaction of Age at Surgery & Time from Surgery

TPA change

Time (yrs)


2. Changes in tibial physeal angle over time can be used to monitorproximal tibial growth status after PTA.

1. Tibial physeal angle remained within typical limits ≥ 3 years after patellar tendon advancement in most patients

3. Age at PTA, time from surgery, amount of correction,and their interactions are the significant risk factors foraltered growth of the proximal tibia.

4. Development of recurvatum post‐surgery is a complex issue not related to altered proximal tibial growth.

Conclusions

LONG‐TERM OUTCOMES: CASES VS. CONTROLS

Liz Boyer, PhD

Long-term outcomes of DFEO+PTA for the treatment of crouch gait

Research questions: 1) Are the short-term effects on gait quality achieved after DFEO+PTA maintained into

adulthood?2) Do individuals who undergo DFEO+PTA for treatment of crouch experience a long-term

beneficial effect on function, participation, activity and/or comfort compared toindividuals who did not receive DFEO+PTA as treatment for their crouch gait?

Study design CASES

Persons with CP

DFEO+PTA surgery 8+ yrs ago

10th-90th % age for DFEO+PTA (11-22 yrs)

KFC ≥10°

Initial knee flexion >2 SD of TD (15°)

Min KF >2 SDs above TD (18°)

Gait data ≤18 mo. prior to surg

20+ yrs old nowCONTROLS

Same criteria but no DFEO+PTA

Current Numbers

42 returned to Gillette (12 more did online surveys) 26 cases (38 limbs) 16 controls (21 limbs)

Results No longer walk 2 (bilat) controls 1 (unilat) case 1 Case had TKA

KNEE KINEMATICS

47AACPDM IC#21 DFEO+PTA

CASES pre short long-term

GAIT DEVIATION INDEX (GDI)

Pre-op ST post LT Post

Case (n=21) 60±9 (43-77) 72±12 (53-94) 65±11 (45-91)

Case (n=37 limbs) 60±8 (43-77) 66±12 (45-91)

Control (n=17) 64±8 (44-77) 63±11 (47-89)

KNEE MOMENTS – Gait


Cases: 58% use assistive devices Controls: 50% use assistive devices

TIMED UP AND GO (sec)

Median (range)

Case (n=25) 18 (8-250)

Control (n=14) 15 (9-89)

5X STS

5X STS – kinetics

Knee Ext Momemt (ND) + Knee Power (ND) - Knee Power (ND)

CASE .023 ± .014 .062 ± .031 -.043 ± .017

CONTROL .039 ± .017 .071 ± .027 -.063 ± .028

Effect size (Cohen’s d)

1.03 0.31 0.86

ND: non-dimensionalized (Pinzone et al (2016). Gait & Posture, 44, 68).

MANUAL MUSCLE TESTING

Both groups: Relatively weaker H extensors & plantarflexors. Relatively stronger K extensors.

Slo

wer


X-RAY MEASUREMENTS

OSTEOARTHRITIS frequency

Medial tib-fem Lateral tib-fem Patellofemoral

Case 0 – 55% 1 – 39% 2 – 5% 3 – 0% 4 – 0%

0 – 32% 1 – 50% 2 – 18% 3 – 0% 4 – 0%

0 – 27% 1 – 35% 2 – 30% 3 – 3% 4 – 5%

Control 0 – 45% 1 – 50% 2 – 5% 3 – 0% 4 – 0%

0 – 45% 1 – 50% 2 – 5% 3 – 0% 4 – 0%

0 – 26% 1 – 42% 2 – 21% 3 – 11% 4 – 0%

Kellgren-Lawerence grade (tib-fem) and Iwano stage (PF). 4 = very severe

KNEE FLEXION CONTRACTURE

Pre-op ST post LT post

CASE 15±5 (10,25) n=38 limbs

-4±6 (-20,0) n=21

-1±11 (-20,15) n=38

CONTROL 12±3 (10,15) n=21

8±7 (-10,20) n=21


QUESTIONNAIRES

CASE CONTROL

Satisfaction with Life (/35) 26 25

Frequency of Participation 1x/2 wks 1x/2 wks

FMS

5 m

50 m

500 m

Sticks Stick

Crutches

Sticks Stick

Walker

WHO-QOL (/5) 4.0 3.9

FAQ (/10) 7±3 7±3

FAQ 22 skills (/10) 13±6 13±6

Pain interfere (10 worse) 2/10 1/10

> pain than “everyday” pain 40% Y 27% Y

On pain meds 7/20 5/21

Pain location

Back

Hips Knees Ankles Feet

1x/mo

< 1x/mo

1x/mo

1x/mo

1x/mo

1-3x/mo

1x/mo

1x/mo

1x/mo

1x/mo

Preliminary results summary 2 controls, 1 case unable to ambulate at long-term; 1 case had TKA

Cases were more severe to begin vs. controls

Cases improved in the short term, slight regression at long-term

Cases superior K kinematics vs. controls at long-term

Cases struggle more at STS tasks

~1/3 cases still in crouch

Controls K kinematics slight improvement at long-term vs. baseline

~1/2 controls still in crouch

Other surgeries/no treatment aren’t as effective to correct K kinematics for controls

Both groups ~similar GDI @ long-term

Groups similar on all questionnaire data @ long-term


QUESTIONS??

[email protected]@[email protected]@[email protected]


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