Poster

The Wagner and University of Texas ulcer classification systems: which is a better predictor of outcome?

Samson Oyibo¹, Edward Jude¹, Ibrahim Tarawneh¹, Hienvu Nguyen², David Armstrong², Lawrence Harkless² and Andrew J.M. Boulton¹ 1Department of Diabetes, Manchester, UK; and 2Department of Orthopedics, San Antonio, TX, USA

Samson Oyibo
San Antonio, TX, USA

Foot ulcers occur in 5–10% of diabetic patients and a third of these may lead to lower limb amputation. The likelihood of amputation increases with ulcer depth and the presence of infection/ischaemia. An ulcer classification system should be easy to use and should help in planning treatment strategies and in predicting clinical outcome.
The objective of this clinical study was to compare two classification systems as predictors of outcome. The Wagner [1] (grade) and the University of Texas [2] (grade and stage) classification systems were both applied to new foot ulcers in two diabetic foot clinics (UK and USA). Ulcer characteristics at presentation were noted and ulcers were followed up until healing or amputation, or for a minimum of 6 months.
During the study period, 194 patients presented with new foot ulcers. Baseline demography and ulcer characteristics are shown in Table I.

Table I: Baseline demography and foot ulcer characteristics in 194 patients

Distribution of ulcers and percentage number of amputations and unhealed ulcers in each grade and stage are shown in Table II. The median (95% CI) time to healing was 10 (8.8–11.6) weeks. Lower limb amputations were performed for 15% of ulcers, whereas 65% of ulcers healed and 16% were not healed at study termination. Four percent of patients died during the study period, the majority due to cardiovascular disease. The Wagner grade and the University of Texas grade and stage showed positive trends with increased number of amputations (p < 0.0001). 

Table II: Number of foot ulcers (% number of amputations) [% number of unhealed ulcers] in each grade and stage

In the University of Texas stage, the risk of amputation was 11 times greater in the presence of infection alone andfive times greater in the presence of ischaemia alone, but with a combination of infection and ischaemia, the risk increased by nearly 15-fold. Only the University of Texas stage showed a positive trend with healing time and it also predicted healing. The greater the stage at presentation the more likely it was for an ulcer not to heal within the study period.
We conclude that the University of Texas system, which combines grade and stage, is more descriptive and shows a greater association with increased risk of amputation and predicts ulcer healing in comparison with the Wagner system. Therefore the University of Texas system, while being simple and easy to use, may be a better predictor of clinical outcome.

References
1. Wagner FW. The dysvascular foot: a system of diagnosis and treatment. Foot Ankle 1981; 2: 64–122.
2. Lavery LA, Armstrong DG, Harkless LB. Classification of diabetic foot wounds. J Foot Ankle Surg 1996; 35: 528–31.

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