Evaluating midcalcaneal length after

Evans calcaneal osteotomy: a

comparison of the locking plate and

tricortical allograft wedge

Garrett M. Wobst, DPM, AACFAS, Nicole M. Protzman, BS, MS,

Raymond E. McCarroll, DPM, FACFAS, Stephen A. Brigido, DPM, FACFAS

IFFAS • AOFAS

Chicago, 2014

My disclosure is in the final AOFAS mobile app.

I have no potential conflicts with this presentation.

Evaluating midcalcaneal length after

Evans calcaneal osteotomy: a

comparison of the locking plate and

tricortical allograft wedge

Garrett M. Wobst

IFFAS • AOFAS

Chicago, 2014

• Evans calcaneal osteotomy remains a

cornerstone in the correction of the

flexible flatfoot (1-5)

• Through lengthening of the lateral

column, tri-planar correction is

consistently achieved (6,7)

INTRODUCTION

Image source: http://www.foot-orthosis.com/tag/flat-foot/

INTRODUCTION

• Many methods have been employed to

maintain the length of the lateral column

(8)

• Tricortical autograft and allograft wedges

• Trabecular metal wedges

• Locking and non-locking plates

• Simple screw fixation

Figure from Butterworth, 2013 (9)

INTRODUCTION

• Compared with a tricortical graft, the locking plate has been shown

to better preserve lateral column length (10)

• Recently, a procedure-specific wedge

locking plate was designed to maintain

the mid-calcaneal length following

Evans osteotomy

Image source: http://footandanklefixation.com/product/

To compare the maintenance of mid-calcaneal length after

Evans calcaneal osteotomy when either a low profile wedge

locking plate or a tricortical allograft wedge was employed

HYPOTHESIS

• The wedge locking plate would better maintain mid-calcaneal length

compared with the tricortical allograft wedge

PURPOSE

Inclusion Criteria

• Presented with a reducible, flexible, symptomatic flatfoot

• Exhausted conservative treatment

• Elected to undergo surgical correction of the deformity

• Evans calcaneal osteotomy was performed

• Either a wedge locking plate or a tricortical allograft wedge was employed to maintain

postoperative mid-calcaneal length

• Minimum radiographic follow-up of 6 months

Retrospective chart review (September 2009 – June 2013)

Exclusion Criteria

• Underwent an adjunctive hindfoot, bony procedure at the time of osteotomy

Materials & Methods

Materials & Methods

• Immediate postoperative period, and

again at 3 months and 6 months

• Distance measured from the most

superior aspect of the convex arc on

the posterior subtalar facet and the

most inferior aspect of the concave arc

on the calcaneus at the calcaneo-

cuboid joint (10)

• Change in mid-calcaneal length o Immediate postoperative

measurements as baseline Figure from Dayton et al. 2013 (11)

Mid-calcaneal Length Measurements

Demographic All Patients

N = 24

Tricortical Allograft

Wedge

n = 9

Wedge Locking

Plate

n = 15

Age (yr) 48.1 ± 17.2 45.7 ± 20.1 49.6 ± 15.8

Body Mass Index (kg/m2) 31.8 ± 6.6 29.6 ± 7.7 32.9 ± 5.8

Gender

Female 18 (75.0) 8 (88.9) 10 (66.7)

Male 6 (25.0) 1 (11.1) 5 (33.3)

Patient Demographics

Results

Data presented as mean ± standard error or count (%).

Results

1.3

2.8

0.5 0.6 0

1

2

3

4

5

3 Months 6 Months

Δ M

id-c

alc

an

ea

l L

en

gth

(m

m)

Time

Tricortical Allograft Wedge Wedge Locking Plate

*

Data presented as mean ± standard error

Change in Mid-calcaneal Length

Discussion

• Our data indicate that the wedge locking plate better maintains mid-

calcaneal length compared with the tricortical allograft wedge 6

months following surgical correction

• Resorption of the allograft wedge at the bone graft interface may

cause a decrease in mid-calcaneal length

REFERENCES

1. Sangeorzan BJ, Mosca V, Hansen ST Jr. Effect of calcaneal lengthening on relationships among the hindfoot, midfoot, and

forefoot. Foot Ankle 14:136-141, 1993.

2. Guha AR, Perera AM. Calcaneal osteotomy in the treatment of adult acquired flatfoot deformity. Foot Ankle Clin 17:247-258,

2012.

3. Butterworth M. Maximizing the effectiveness of the Evans calcaneal osteotomy. Podiatry Today 26:20-26, 2011.

4. DeYoe BE, Wood J. The Evans calcaneal osteotomy. Clin Podiatr Med Surg 22:265-276, vi, 2005.

5. Roye DP Jr, Raimondo RA. Surgical treatment of the child’s and adolescent’s flexible flatfoot. Clin Podiatr Med Surg 17:515-

530, vii-viii, 2000.

6. Evans D. Calcaneo-valgus deformity. J Bone Joint Surg Br 57:270-278, 1975.

7. Arangio GA, Chopra V, Voloshin A, Salathe EP. A biomechanical analysis of the effect of lateral column lengthening

calcaneal osteotomy on the flat foot. Clin Biomech (Bristol, Avon) 22:472-477, 2007.

8. Abbasian A, Zaidi R, Guha A, Goldberg A, Cullen N, Singh D. Comparison of three different fixation methods of calcaneal

osteotomies. Foot Ankle Int 34:420-425, 2013.

9. Butterworth M. Maximizing the effectiveness of the Evans calcaneal osteotomy. Podiatry Today 26:20-26, 2011.

10. Dayton P, Prins DB, Smith DE, Feilmeier MJ. Effectiveness of a locking plate in preserving midcalcaneal length and

positional outcome after Evans calcaneal osteotomy: a retrospective pilot study. J Foot Ankle Surg 52:710-713, 2013.

11. Dayton P, Wienke JC Jr, Prins DB, Haulard JP, Feilmeier MJ, Wiarda C. Measurement of mid-calcaneal length on plain

radiographs: reliability of a new method. Foot Ankle Spec 4:280-283, 2011.