Robin Queen, PhD

Samuel B Adams, MD

Mark E. Easley, MD

James K. DeOrio, MD

James A. Nunley, MD

Robert J. Butler, DPT, PhD

Total Ankle Replacement Does Not Alter Lower Extremity Kinematics

During Sit-to-Stand Movement

Total Ankle Replacement Does Not Alter Lower Extremity Kinematics During Sit-to-Stand Movement

Robin M. Queen, PhD

Conflict

of

Interest

Disclosures are in the Final

AOFAS Program Book

Background & Purpose

• Total Ankle Replacement (TAR) is an alternative to arthrodesis for end-stage, painful ankle OA 1-3, 5-6

• Little know about patient function and sit-to-stand mechanics change following TAR4

• One argument for TAR, especially with a contralateral arthrodesis, is to preserve the ability to stand up

End Stage OA

TAR Arthrodesis

• Examine changes in sit-to-stand mechanics between the surgical and non-surgical limbs across time (pre-op, 1 yr and 2 yr post-TAR

Purpose

Methods

99 Consecutive TAR patients

Exclusion:

• Revision TAR

• Fusion Takedown,

• Contralateral TAR • Current or planned

• Use of Assistive Device

• RA

N = 51

N = 48

Assessment Times: • Pre-op • 1 year post-op • 2 years post-op

Mean ± SD

Age (yrs) 62.7 ± 9.6

Height (m) 1.71 ± 0.1

Weight (kg) 85.16 ± 17.5

Methods

• Motion Camera Data Collected at

120 Hz

• Force Plate Data Collected at

1200Hz

• Patients Complete 5 sit-to-stand

trials as quickly as possible in

standard chair

• Feet were placed one on each

force plate to measure forces

and moments on both Surgical

and Non-Surgical Side

Interaction between Side and Time

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Pre-op 1 year 2 year

Mo

men

t (N

m/k

g)

GRF-S GRF-NS

Hip Ext-NS Hip Ext-S

Ankle PF-S Ankle PF-NS

Vert

ical G

RF

(B

W)

Differences Across Time

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Knee Extension Angle

* +

No differences between S and NS Significant differences across time (*pre-op to 2yr, + 1yr to 2 yrs)

Pre

-op

1 y

ea

r

2 y

ea

r

Differences Between Surgical and Non-Surgical Sides

0

2

4

6

8

10

12

Hip Extension Angle Ankle DF Angle

Sig. diff between the S and NS sides independent of time (p<0.001)

Su

rgic

al

No

n-S

urg

ica

l

Conclusions

• Entire lower extremity demonstrated altered movement and loading patterns following TAR

• Sit-to-stand remained altered up to 2 years post-TAR

• Lack of normal ankle mobility results in altered lower extremity mechanics - compensate for missing ankle dorsiflexion

• Important to examine multiple tasks, not just walking to understand the effect of TAR on function and ADL

References

1) DeOrio, J. K.: Focus on total ankle arthroplasty. Orthopedics, 29(11): 978-80,

2006.

2) Haddad, S. L.; Coetzee, J. C.; Estok, R. et al.: Intermediate and long-term

outcomes of total ankle arthroplasty and ankle arthrodesis. A systematic review of

the literature. J Bone Joint Surg Am, 89(9): 1899-905, 2007.

3) Houdijk, H.; Doets, H. C.; van Middelkoop, M.; and Dirkjan Veeger, H. E.: Joint

stiffness of the ankle during walking after successful mobile-bearing total ankle

replacement. Gait Posture, 27(1): 115-9, 2008.

4) Kim, B. S.; Choi, W. J.; Kim, Y. S.; and Lee, J. W.: Total ankle replacement in

moderate to severe varus deformity of the ankle. J Bone Joint Surg Br, 91(9): 1183-

90, 2009.

5) Saltzman, C. L.; Mann, R. A.; Ahrens, J. E. et al.: Prospective controlled trial of

STAR total ankle replacement versus ankle fusion: initial results. Foot Ankle Int,

30(7): 579-96, 2009.

6) Swiontkowski, M. F.; Engelberg, R.; Martin, D. P.; and Agel, J.: Short

musculoskeletal function assessment questionnaire: validity, reliability, and

responsiveness. J Bone Joint Surg Am, 81(9): 1245-60, 1999.

7) Thomas, R.; Daniels, T. R.; and Parker, K.: Gait analysis and functional outcomes

following ankle arthrodesis for isolated ankle arthritis. J Bone Joint Surg Am, 88(3):

526-35, 2006.