Early Radiographic Changes in the Lateral Talocalcaneal Angle Following Achilles Tenotomy in Children With Idiopathic Clubfoot

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 three 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 three groups of patients (F=31.48, P<0.001). 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. LEVEL OF EVIDENCE: III.

Simultaneous subtalar arthroeresis, midfoot soft tissue release, and talo-navicular arthrodesis in children with planovalgus neurologic foot

PURPOSE

Planovalgus foot deformity (PVFD) is common in children with neuromuscular conditions and severe deformity may require surgical correction. This study aims to assess clinical and radiological outcomes of PVFD secondary to neuromuscular disease managed by subtalar arthroeresis (SuAE), midfoot soft tissue release and talo-navicular arthrodesis (TNA).

METHODS

A retrospective analysis of children with neuromuscular disease and nonreducible PVFD who underwent SuAE, midfoot soft tissue release, and TNA and with a minimum follow-up of 5 years was performed. A total of 60 patients with neuromuscular disease (108 feet) including cerebral palsy were reviewed. Mean age at surgery was 12.7 ± 4.6 years (6-17). Mean follow-up was 7 ± 2.9 years (5-10). Clinical outcomes and radiologic correction at final follow-up were compared with preoperative values. Statistical analysis was performed and significance was set at P < 0.01.

RESULTS

Statistically significant radiological improvements between pre- and postoperative values were found for all angle values. At final follow-up, there was a significant improvement in VAS score (4.8 vs. 2; P < 0.01). There was also a positive trend in the improvement of walking ability. No cases of pseudoarthrosis were reported at final follow-up. Screw removal was required in 5 out of 108 feet (4.6%) and 2 feet (3.3%) had delayed medial wound healing.

CONCLUSIONS

SuAE combined with TNA and midfoot soft tissue is a safe and feasible procedure that can provide good clinical and radiologic results in patients with neuromuscular disease and nonreducible PVFD; the procedure can improve foot stability, and has a limited number of complications.

LEVEL OF EVIDENCE

IV.

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.

Automating Angle Measurements on Foot Radiographs in Young Children: Feasibility and Performance of a Convolutional Neural Network Model

Measurement of angles on foot radiographs is an important step in the evaluation of malalignment. The objective is to develop a CNN model to measure angles on radiographs, using radiologists' measurements as the reference standard. This IRB-approved retrospective study included 450 radiographs from 216 patients (< 3 years of age). Angles were automatically measured by means of image segmentation followed by angle calculation, according to Simon's approach for measuring pediatric foot angles. A multiclass U-Net model with a ResNet-34 backbone was used for segmentation. Two pediatric radiologists independently measured anteroposterior and lateral talocalcaneal and talo-1st metatarsal angles using the test dataset and recorded the time used for each study. Intraclass correlation coefficients (ICC) were used to compare angle and paired Wilcoxon signed-rank test to compare time between radiologists and the CNN model. There was high spatial overlap between manual and CNN-based automatic segmentations with dice coefficients ranging between 0.81 (lateral 1st metatarsal) and 0.94 (lateral calcaneus). Agreement was higher for angles on the lateral view when compared to the AP view, between radiologists (ICC: 0.93-0.95, 0.85-0.92, respectively) and between radiologists' mean and CNN calculated (ICC: 0.71-0.73, 0.41-0.52, respectively). Automated angle calculation was significantly faster when compared to radiologists' manual measurements (3 ± 2 vs 114 ± 24 s, respectively; P < 0.001). A CNN model can selectively segment immature ossification centers and automatically calculate angles with a high spatial overlap and moderate to substantial agreement when compared to manual methods, and 39 times faster.

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.

The Predictive Value of Radiographs and the Pirani Score for Later Additional Surgery in Ponseti-Treated Idiopathic Clubfeet, an Observational Cohort Study

There are few validated predictors of the need for additional surgery in idiopathic clubfeet treated according to the Ponseti method. Our aim was to examine if physical examination (Pirani score) and radiographs at the age of three months (after initial correction of the clubfeet) can predict the future need for additional surgery. In this retrospective cohort study, radiographs of idiopathic clubfeet were made at the age of three months. The Pirani score was determined at the first cast, before tenotomy, and at the age of three months. Follow-up was at least five years. The correlation between the radiograph, Pirani score, and the need for additional surgery was explored with logistic regression analysis. Parent satisfaction was measured with a disease-specific instrument. The study included 72 clubfeet (50 children) treated according to the Ponseti method. Additional surgery was needed on 27 feet (38%). A larger lateral tibiocalcaneal angle (i.e., equinus) and a smaller lateral talocalcaneal angle (i.e., hindfoot varus) at the age of three months were correlated with the need for additional surgery. Higher Pirani scores before tenotomy and at the age of three months also correlated with additional surgery. Parent satisfaction was lower in patients who needed additional surgery. Both the Pirani scores and the lateral radiographs are predictive for future additional surgery.

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.

Well though-out introduction of percutaneous Achilles tenotomy during functional treatment of congenital talipes equinovarus: Which indications produce the best results?

INTRODUCTION

Percutaneous Achilles tenotomy (PAT) was recently added to functional treatment of congenital talipes equinovarus (aka clubfoot). The aim of this study was to determine the relevance of a carefully chosen radiological criterion for the PAT indication and to evaluate its results.

HYPOTHESIS

When the tibiocalcaneal angle (aTiCa) is larger than 75° at 4 months, doing PAT will improve the results of the functional method in the medium term and will reduce the surgery rate.

PATIENTS AND METHODS

This prospective study involved 101 patients (151 feet) born between 2011 and 2014 with clubfoot who were treated with the French functional method and had at least 4 years' follow-up. The initial severity of the deformity was evaluated using the Diméglio scoring system. In our sample, 30 feet had a Diméglio rating of II (20%), 61 had a Diméglio rating of III (40%) and 60 feet had a Diméglio rating of IV (40%). The indication for PAT was made at 4 months of age when the aTiCa on a lateral radiograph of the foot in maximum correction was greater than 75°. The mean follow-up was 5 years. The final assessment was done using the modified Ghanem and Seringe classification.

RESULTS

In the entire cohort, PAT was done in 113 feet (75%). None of the feet required a repeat PAT. Surgical release of the soft tissues was done in 20 feet (13%). None of the feet developed a rocker bottom deformity. Two feet were operated in the absence PAT (out of 38 in this subgroup) and 18 feet after PAT (out of 113 in this subgroup). The aTiCa angle did not vary in the PAT group based on whether surgical release was indicated afterwards or not. At the final assessment, 140 feet (93%) were classified as very good and 11 feet (7%) as good.

DISCUSSION

The tibiocalcaneal angle is a relevant radiological criterion for the PAT indication in children with clubfoot. PAT has a positive impact on the outcomes.

LEVEL OF EVIDENCE

II; prospective study.