Radiographic Outcomes Following Primary Arthrodesis of the First Metatarsophalangeal Joint in Hallux Abductovalgus Deformity• Presenter: Wenjay Sung, DPM

• Authors: Wenjay Sung DPM, Patrick R. Burns, DPM, and Dane K. Wukich, MD

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Radiographic Outcomes Following Primary Arthrodesis of the First Metatarsophalangeal

Joint in Hallux Abductovalgus Deformity

Wenjay Sung, DPM

My disclosure is in the Final AOFAS Program Book. I have no potential conflicts with this

presentation.

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Purpose

• Evaluate radiographic outcomes of primary 1st MTPJ arthrodesis – For hallux abductovalgus

• Effect on deformities based upon magnitude• Correlate the effect of the procedure using a relatively larger

spectrum of data.

– Determine usefulness in correction of commonly utilized radiographic measurements 

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Methods

• IRB approval obtained– March 2004 – January

2009– 115 records– Excluding:

• Previous 1st ray surgeries• Incomplete medical records• Hallux varus deformity• Did not meet hallux valgus

deformity criteria (Coughlin)

– 58 feet (56 patients)

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Methods

• Procedure– Conical reamers– Rigid internal fixation

• Post-operative– 10-14 days in splint– WBAT in rigid boot or

shoe– Radiographs at each

follow-up for at least 3 months post-surgery

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Methods

• Measurements– Primary radiographic

measurements• Pre-operative versus post-

operative– Hallux Valgus angle (HA)– 1st-2nd Intermetatarsal

angle (IM)– Secondary radiographic

measurements• Presence of pre-operative 1st

MTPJ arthritis

• Groups– Divided by IM severity

• Mild, moderate, severe

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Statistical Analysis

• Using SPSS version 14.0 (SPSS Science Inc, Chicago, IL) – Descriptive and

Inferential Statistics Calculated

• A two-way repeated measures analysis of variance (ANOVA)

• Pre-op and post-op outcomes

• For 3 different groups

– A one-way ANOVA• Compare differences

between groups

– The a priori level was 0.05 for all statistical tests.

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Results

• Overall (N = 58)• Median length of follow-up 12 months

– (mean 17.7 months, range 3 – 68 months)

• Patient demographics– 45 of 56 patient were female– 32 of 58 procedures were on right foot

• Union rate of 94.8% (55 of 58 joints) – Average HA correction = 18.50

• P < 0.01

– Average IM correction = 4.20

• P < 0.01

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Results

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Results

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Results

• Further analysis– Significant incremental post-operative

correction with increasing deformity for 1st- 2nd intermetatarsal angle

• Mild vs Severe (P < 0.01)• Moderate vs Severe (P < 0.05)

– No significant difference in post-op hallux valgus angle amongst groups

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Post-operative angle correction

0

5

10

15

20

25

30

Mild Moderate Severe

HA correction

IM correction

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Discussion

• Limitations– Retrospective design

• Assessor bias • Measurement bias• Non responder bias• Our minimum follow up of three months may be considered

less than ideal

– No control group

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Discussion

• The mean HA and IM decreased significantly – HA 31.90 to 13.40 (P < 0.01)– IM 14.00 to 9.70 (P < 0.01)

• Primary first MTPJ arthrodesis is not commonly associated with mild hallux abductovalgus correction without degenerative changes.

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Conclusion

• The amount of postoperative radiographic correction after MTPJ arthrodesis improves correspondingly. – Higher amounts of correction are achieved in

deformities with the most severe preoperative angular measurements