Early radiographic risk factors for rigid relapse in idiopathic clubfoot treated with the Ponseti method

Early Radiographic Characteristics of the Lateral Talocalcaneal Angle and its Predictive Significance for Relapse in Patients With Idiopathic Clubfoot Treated With the Ponseti Method

In order to evaluate the early radiographic characteristics of the lateral talocalcaneal (L-TC) angle in patients with idiopathic clubfoot (ICF) and to investigate its prognostic significance for relapse after initial treatment with the Ponseti method. We retrospectively included 151 patients (96 males and 55 females; 227 feet) with ICF treated at our Institution between January 2005 and December 2014. The age at initial treatment was less than 6 months, and radiographs were obtained within 3 months of the Achilles tenotomy (mean age: 2.3 months; range: 0.77-6.8). All patients were followed up for at least 7 years (range, 7-18). The participants' feet were classified into 3 groups: relapsed (Group A), not relapsed (Group B), and normal foot groups which consisted of healthy feet in patients with unilateral ICF (Group C). All angle measurements were expressed in degrees. Forty-seven ICF feet in 33 patients relapsed, while 180 feet in 118 patients did not, and the age at relapse was 5.92 ± 1.91 years. Seventy-five normal feet were included in Group C. The average L-TC angle in Group A and B patients was 33.57° ± 12.05° and 39.37° ± 12.55°, respectively, while Group C was 49.61° ± 9.11°. A significant difference was found among the 3 groups of patients (F = 31.48, p < .001). The L-TC angle cut-off value below which a recurrence could be predicted was 36.1° (sensitivity, 74.47%). The L-TC angle of ICF patients treated using the Ponseti method were reduced compared to normal feet. An L-TC angle of <36.1° has relative value in predicting ICF relapse.

Radiographic Impact on the Clinical Decision Making of Achilles Tenotomy in Clubfoot: In Search of an Objective Cut-Off Value

BACKGROUND

We tried to determine whether the indication of Achilles tenotomy (AT) in clubfoot patients based on clinical evaluation could be confirmed radiographically, and to find an objective radiographic cut-off value for its indication.

METHODS

Eighty-six clubfeet from 60 patients, (26 bilateral and 34 unilateral) were included. A standard Ponseti treatment regimen was applied. Group 1 comprised patients who underwent AT immediately after serial plaster casting (26 feet). Group 2 comprised patients who underwent AT during the follow-up period (48 feet). Group 3 comprised patients who were assumed to have a corrected foot and did not undergo AT (12 feet). Group 4 comprised the healthy sides of the unilateral cases (34 feet).

RESULTS

Both Group 1 and Group 2 showed significant improvement after tenotomy (p = 0.002). In order to differentiate between the normal and AT groups according to the pre-tenotomy angle, we obtained an optimal cut-off value of >85° according to the Youden index, a sensitivity of 96%, a specificity of 91.2%, a positive predictive value of 95.9%, a negative predictive value of 91.2%, and an accuracy rate of 94.4% (AUC: 0.983; p < 0.001).

CONCLUSIONS

Feet with a lateral tibio-calcaneal angle > 85° can be considered pathologic and accepted as candidates for AT.

A study on the effect of radiographic angles on clubfoot's recurrence

Clubfoot is one of the common orthopaedic deformities. However, regardless of its' treatment high success rate, recurrence of the deformity is a serious issue. The aim of this study is to evaluate if radiographic angles can be used for clubfoot recurrence prediction. This is a prospective study on 91 patients (134 feet) with mean age of 9.5 ± 2.3 days and male/female ratio of 2/1 on patients with congenital clubfoot admitted to our hospital. Pre and one-year post-tenotomy tibiocalcaneal (TIC-L), talocalcaneal (TC-L) and calcaneal-first metatarsal angles (C1M-L) in the lateral view of the patients' radiographs, and their recurrence status until three years were measured. Ten feet experienced relapse. The mean pre and one-year follow-up measurements of TC-L, C1M-L, and TIC-L angles were significantly different between patients who experienced relapse and others (P < .05). The cut-off points of 1.75 and 6.5 for one-year follow-up Pirani and Dimeglio scores for recurrence prediction were suggested respectively. Also, cut-off points of 26.5 and 79.5 for one-year follow-up TC-L and TIC-L angles for recurrence prediction were calculated, respectively. We demonstrated that the pre-tenotomy and one-year follow-up TIC-L, TC-L, and C1M-L angles are helpful in clubfoot recurrence prediction after Ponseti treatment.

Are early antero-posterior and lateral radiographs predictive of clubfoot relapse requiring surgical intervention in children treated by Ponseti method?

Purpose

To investigate the value of antero-posterior and lateral radiographs in predicting clubfoot relapse after treatment with the Ponseti method.

Methods

This was a retrospective review of 104 children (157 feet) younger than 3 months of age with idiopathic clubfoot treated using the Ponseti method at our institution between January 2007 and December 2014. All patients underwent Achilles tenotomy and were divided into two groups according to the need for further surgery to correct the deformity: relapsed group (24 patients; 36 feet) and non-relapsed group (80 patients; 121 feet). All antero-posterior and lateral foot radiographs were performed less than 3 months after Achilles tenotomy. The talo-calcaneal (TC-AP) and talus-first metatarsal (TM-AP) angles were measured in the antero-posterior view, while the tibio-calcaneal (TIC-L), talus-first metatarsal (TM-L), and talo-calcaneal (TC-L) angles were measured in the lateral view. The multi-factor logistic regression model of the stepwise selection method was used to predict the relapse of clubfoot deformity from the potential predictive values.

Results

The mean age at initial plain radiography examination was 99.45 ± 21.54 days. Differences in TC-AP, TM-AP, TC-L, and TIC-L between the two groups were statistically significant. However, only TM-AP and TIC-L were included in the "risk of relapse" formula using the multi-factor logistic stepwise selection method.

Conclusion

Early antero-posterior and lateral radiographs in children younger than 3 months of age at initial Ponseti treatment have positive predictive value for relapse. Reduced TM-AP angle and increased TIC-L were associated with an increased risk of relapse.

Level of evidence

level III.