The Heel Pad in Congenital Idiopathic Clubfoot: Implications of Empty Heel for Clinical Severity Assessment.

BACKGROUND

Clubfoot has been evaluated in many ways, including the most common classifications of clubfoot, described by Caterrall and Piraniis based on six clinical signs. The purpose of this study was to gain better understanding of the heel pad in relation to the term "empty heel", and to propose modification of clubfoot severity scoring system based on "empty heel".

METHODS

A combination of prospective study of 79 clubfoot patients treated with Ponseti method and literature review of heel pad anatomy and biomechanics. The setting was a university teaching hospital. The ethical research committee approved study protocol and informed consent of patients' parent obtained. The selection criteria included patients' diagnosed congenital idiopathic clubfoot, age < 2 years, no history of previous treatment and tenotomy indicated. An evaluation of patient was assessed by orthopaedic surgeons trained on Ponseti method and has above 5 years experience. Data analysis performed on the age, sex, Pirani scores at onset of treatment, tenotomy, and 6 month after initial full correction.

RESULTS

One hundred and thirty-two clubfeet in 79 patients (56 males, 23 females) completed Ponseti protocol. The median age at presentation was 5.2 months (range 0.1-23.7 months). The mean right foot abduction after correction 57.30 (S.D. 9.20), and for the left foot, was 56.30 (S.D. 9.40). The mean right foot dorsiflexion was -13.70 (S.D. 18.40) before correction while after correction, it was 20.00 (S.D. 4.50) and for the left, the mean was -8.50 (S.D. 9.60) before correction and 21.00 (S.D. 4.30) after correction. Eighteen (22.8%) patients (10 bilateral, 9 unilateral) had clubfeet with empty heel score above zero point at initial full correction (p<0.001). Clinic anatomy shows the heel pad is a solid complex structure existing in normal, moderate and severe atrophied form. Heel pad is attached tightly to calcaneus without a cavity for the calcaneus to drop.

CONCLUSIONS

Heel pad probably could replace "empty heel" in modify Pirani scoring system. Clinical indication for repeat tenotomy should be based on equinus, not on the feeling of an empty heel, and families can be advised that the heel pad has a tendency to remodel over time to a normal shape.

LEVEL OF EVIDENCE: Level II.

CLINICAL RELEVANCE: Empty heel feeling at initial full correction of congenital idiopathic clubfoot based on Ponseti protocol is not indication for repeat tenotomy.