Too-long calcaneal process: Results of surgical treatment and prognostic factors

Imaging characteristics of too-long anterior process syndrome in children and adolescents

BACKGROUND

In the presence of pain over the lateral aspect of the foot or recurrent ankle sprain in children, medical imaging is often employed to investigate potential causes, such as a calcaneonavicular coalition or a too-long anterior process (TLAP) of the calcaneus. Diagnosis and categorization of calcaneonavicular coalitions (synostosis, synchondrosis, or synfibrosis) is generally facilitated through imaging, in contrast to TLAP, which lacks well-defined semiological characteristics, apart from a calcaneonavicular space measurement of less than 5 mm. However, this measurement initially performed on an oblique view radiograph can be subject to a lack of precision due to positional variations of the foot and overlapping bones. Furthermore, the differentiation between TLAP as an anatomical variant and TLAP syndrome (characterized by symptomatic presentation), remains a subject of uncertainty.

OBJECTIVE

The objective of our retrospective study was to investigate the imaging diagnosis of TLAP syndrome.

MATERIALS AND METHODS

A retrospective unmatched case-control study was conducted, covering data from February 2014 to January 2021. All patients, included retrospectively and consecutively, were initially managed in our hospital with radiography and/or computed tomography (CT) and/or magnetic resonance imaging (MRI). Two radiologists independently reviewed the images taken (radiographs, CT scans, and MRIs) of patients undergoing treatment in pediatric orthopedics for TLAP syndrome and control subjects, utilizing a standardized questionnaire. The control group consisted of subjects with no features suggestive of TLAP syndrome. The questionnaire included measurements of the calcaneonavicular space and identification of indirect signs associated with calcaneonavicular coalitions, as described in the related literature.

RESULTS

A total of 128 patients who met the inclusion criteria were included in the analysis, including 38 patients and 90 controls. The prevalence of TLAP was 71.5% in the study population and 62.6% among controls. A threshold measurement of the calcaneonavicular space at 3.2 mm favored TLAP syndrome (sensitivity=97%, specificity=70%, area under the curve [95% confidence interval] =0.881[0.812-0.949]), with better precision using CT. Three indirect signs were significant: the "anteater nose" sign, the talar beak, and the tapered anterior calcaneal process. These signs demonstrated an even stronger association with TLAP syndrome when observed in conjunction with a reduction in the calcaneonavicular space, particularly in CT scans.

CONCLUSION

TLAP is common among control subjects. Therefore, a variant appears to be the most plausible explanation and it can be considered a mild form of calcaneonavicular coalition. However, in conjunction with symptoms suggestive of TLAP syndrome, the diagnosis is further supported by imaging, specifically with a calcaneonavicular space measurement of less than 3.2 mm. This measurement is most accurately obtained using CT with 2-dimensional reconstructions in all three planes. The simultaneous presence of the "anteater nose" sign, the talar beak, or the tapered anterior calcaneal process provides additional diagnostic evidence. In the diagnostic approach of calcaneonavicular coalition, oblique foot radiography seems useful in initially detecting abnormal coalition (bony or not), and complementarily, CT emerges as the best modality to characterize TLAP syndrome.

Acute ankle injuries: association between sprain severity and ancillary findings

Miranda et al. reported a correlation between the significance of injuries to osseous, chondral, tendon, and ligamentous tissues in participants with low-grade versus high-grade acute ankle sprains. They demonstrated that participants with high-grade ankle sprains presented with shorter calcaneonavicular distances and increased rates of structural abnormalities compared to those with low-grade sprains. Special attention should be paid to acute ankle sprains in emergency settings to avoid failure in detecting severe injuries that could lead to chronic pain, impairment, or instability. Participants presenting acute ankle sprains (<15 days) were divided into low-grade versus high-grade sprain,according to the presence of a complete tear in at least one component of lateral ligament complex. High-grade ankle sprains group presented increased rates of medial malleolus bone bruise, deltoid ligament tears,extensor retinaculum lesions, and articular effusion. The calcaneonavicular distance was statistically shorter in patients with high-grade sprains (median, 3.0mm) when compared to those with low-grade sprains (median, 4.0mm) Objective: To correlate the significance of osseous, chondral, tendon, and ligamentous injuries with anatomical variations in low-grade versus high-grade acute ankle sprains.

METHODS

We retrospectively identified the magnetic resonance imaging findings of acute ankle sprains (<15 days). Participants with a history of previous sprains, arthritis, tumors, infections, or inflammatory conditions were excluded. Images were independently evaluated by two musculoskeletal radiologists and assessed for osseous, chondral, tendon, and ligamentous injuries and anatomical variations. Participants were divided into low-grade versus high-grade sprain groups, according to the presence of a complete tear in at least one component of the lateral ligament complex.

RESULTS

The final study group comprised 100 magnetic resonance images (mean age, 36 years), the majority of males (54%), the right ankle (52%), and a mean sprain duration of 5 days. Participants with high-grade sprains presented with increased rates of medial malleolus edema (p<0.001), moderate and large articular effusions (p=0.041), and shorter calcaneonavicular distance (p=0.008). Complete tears of the anterior talofibular ligament and calcaneofibular ligaments were observed in 100% and 51.2% of the participants in the High-Grade Group, respectively. The deltoid ligament complex was partially torn in this group (55.8% versus 8.8%, p<0.001). Extensor tendon retinaculum lesions occurred significantly more frequently in this group (41.9%) compared to the overall study population (23%) (p<0.001).

CONCLUSION

Participants with high-grade ankle sprains presented with shorter calcaneonavicular distances and increased rates of medial malleolus edema, deltoid complex partial tears, extensor retinaculum lesions, and articular effusion.

Pediatric Flatfoot: Is There a Need for Surgical Referral?

Pediatric foot deformities are a common finding, concerning up to 44% of preschool aged children. The absence of accepted international guidelines, as well as heterogeneity in definitions and measurements, makes management of pediatric flatfoot a challenge, and decisions surrounding specialized care referral confusing and biased. The objective of this narrative review is to provide guidance to primary care physicians treating these patients. A non-systematic review of the literature regarding the development, etiology, and clinical and radiographic assessment of flatfeet using the PubMed and Cochrane Library databases was performed. The exclusion criteria for the review were adult populations, papers detailing the outcome of a specific surgical procedure, and publications prior to 2001. The included articles showed great heterogeneity in definition and proposed management, which makes the study of pediatric flatfoot challenging. Flatfoot is a common finding in children under 10 years old, and should not be considered pathological unless stiffness or functional limitation are present. Surgical referral should be reserved to children with stiff or painful flatfoot, while simple observation is indicated for flexible, asymptomatic flatfeet.

Anatomical characterization of the too-long anterior process of the calcaneum: a computed tomography scan analysis of 69 feet

Our work aims to identify and measure the morpho-anatomical characteristics of too-long anterior calcaneal process based on computed tomography scans done in patients with a history of pain and who have experienced repeated ankle sprains. The computed tomography scans of 69 feet were reviewed. These scans were used to calculate (1) the calcaneo-navicular distance; (2) the height, length, and width of the too-long anterior calcaneal process; (3) the length of the calcaneum; (4) the angle of the too-long anterior calcaneal process in the sagittal (anterior-superior angle), axial (anterior-medial angle), and frontal plane. Out of 69 feet, forty-nine were pathological (71%) with abnormalities of the too-long anterior calcaneal process, while the rest (29%) had no morphological abnormalities. The calcaneo-navicular distance was found to be <5 mm (mean: 2.8 ± 1.2 mm) in all pathological feet, which also had significantly reduced calcaneo-navicular distance ( P < 0.001) and longer bone portion distal to the calcaneocuboid tangent ( P < 0.001) in comparison to normal feet. In pathological feet, the mean too-long anterior calcaneal process length was 10.7 ± 1.9 mm; the mean anterior-superior angle was 29.6 ° ± 11.6, the mean angle anterior-medial angle was 40.7 ° ± 8.3, the mean angle frontal plane was 74.2 ° ± 14.1. Similar to a cone or a parallelepiped, the too-long anterior calcaneal process has a complex three-dimensional anatomy, with a superior, medial, and anterior direction. Using the measurements obtained, four different too-long anterior calcaneal process morphotypes could be identified: absence of TLACP, triangular shape, rectangular shape, and coalition (level of evidence III).

Interrelations Between the Too-Long Anterior Calcaneal Process, Hind and Mid-tarsal Bone Volumes, Angles and Osteochondral Lesion of the Dome of the Talus: Analysis by Software Slicer of 69 CT Scan of Feet

Introduction

Although the association between Too-Long Anterior Calcaneal Process (TLACP) and osteochondral lesion of the dome of the talus (OCL) has been hypothesized, no study has investigated the interrelations between TLACP, hind and mid-tarsal volumes and angles and the development of OCL. The main goals of this work are: (1) to measure the volume of the calcaneum, talus, navicular and cuboid in subjects with and without TLACP; (2) to evaluate the angular relationships between talus, calcaneum and navicular in subjects with and without TLACP; (3) to assess whether TLACP has an effect on the volume of OCL.

Methods

This is a retrospective study of 69 CT scans of 54 consecutive children aged 11-15 years who had undergone a CT scan due to symptomatology suggestive of TLACP. The 3D Slicer software allowed to calculate the volume of the talus, calcaneum, navicular, cuboid, TLACP and OCL (in cm3). The PACS system was used to perform the angular measurements (in degrees) between talus, calcaneum and navicular in the frontal, axial and sagittal plane.

Results

Amid the 69 CT scans, 49 were found to have pathologies related to TLACP (71%, TLACP Group) and 20/69 were normal (29%, Control Group). The mean hind and mid-tarsal bone volumes of the TLACP group were comparable to those of the control group. There were 40 (81.6%) OCLs detected exclusively in pathological feet (TLACP group); 32 lesions were medial (80%), and 8 lesions were lateral (20%). According to Ferkel and Sgaglione CT Staging System, there were 22 (55%) stage 1 lesions, 5 (12.5%) stage 2A, 3 (7.5%) stage 2B and 10 (25%) stage three lesions. Only the angle between the talus and calcaneum in the frontal plane was significantly lower in pathological feet with respect to the control group (p < 0.001). In pathological feet, the talus was supinated, and the calcaneus pronated.

Conclusions

TLACP tend to stiffen the foot, modifying its biomechanics and leading to supination of the talus and pronation of the calcaneum. This induces an overpressure at the medial side of the talus where we observed a greater frequency of medial OCL with larger volume than lateral OCL.

Level of Evidence

III.

Lateral endoscopy of the sinus tarsi: Anatomy, technique and current indications

Numerous pathologies are reported in the lateral mid- and hind-foot. Access to the sinus tarsi is difficult, making lateral endoscopy the preferred approach. The present technical note describes the anatomy, technique and current indications for lateral endoscopy of the sinus tarsi.

The too-long anterior process and osteochondral lesion of the talus: Is there an anatomical predisposition? A case-control study on 135 feet

INTRODUCTION

The too-long anterior process (TLAP) increases mechanical stress on the hindfoot and could lead to osteochondral lesions of the talus (OLT) by localized hyper-pressure. The purpose of this study is to investigate an association between TLAP and OLT in children.

METHODS

This is a retrospective, multicenter, case-control study conducted between 2010 and 2020. The OLT group was compared to a control group (CoG). TLAP is characterized by a distance between the anteromedial process of the calcaneus and the navicular bone (CN) of< 5 mm.

RESULTS

Forty-three feets were included in the OLT group and 92 in the CoG. The OLT group had a lower CN distance on CT than the CoG, a median of 2.8 mm versus 3.75 mm (p = 0.002); 86% of patients (37 feet/43) in the OLT group had a CN distance of< 5 mm (OR=3.0 [1.1; 9.5], p = 0.023) compared to 67% in the CoG.

DISCUSSION

The OLT group had an increased risk of developing TLAP compared to the CoG.

LEVEL OF EVIDENCE

III.

Post-operative outcomes of arthroscopic tarsal coalition resection: A systematic review

BACKGROUND

Arthroscopic resection of tarsal coalitions is a relatively new technique. This systematic review aimed to investigate the post-operative complications and functional outcomes in arthroscopic resection of tarsal coalitions.

METHODS

PubMed, Medline, Embase and Cochrane library were searched for studies that reported outcomes in arthroscopic resection of tarsal coalitions.

RESULTS

8 studies met the inclusion criteria. Post-operative outcomes were reported in 103 cases. The overall complication rate was 13.6%. Tibial nerve injury was reported in 1 patient. All included studies demonstrated post-operative improvement in functional outcomes.

CONCLUSION

Arthroscopic resection is a feasible and effective treatment method for symptomatic tarsal coalitions.

Does arthroscopic resection of a too-long anterior process improve static disorders of the foot in children and adolescents?

PURPOSE

A too-long anterior process of the calcaneus is a common cause of pain and hind-foot instability. Our goal was to evaluate the early results of arthroscopic resection in terms of static foot disorders in children and adolescents.

METHODS

We retrospectively studied 11 ft (10 patients). The inclusion criteria were treatment of TLAP by arthroscopic resection and a minimum follow-up period of six months. Surgery was indicated in cases with persistent symptomatic TLAP resistant to orthopaedic treatment.

RESULTS

The mean age at surgery was 11 (range, 7-15) years. The mean follow-up duration was 15 (range, 8-28) months. Pre-operatively, we diagnosed four flat feet, two cavus feet and five feet with normal footprints, but loss of physiological hind-foot valgus. All patients presented with subtalar joint stiffness. At the last follow-up, four feet with no hind-foot valgus were normal, two were unchanged and the other feet had improved. The mean AOFAS increased from 61.9 (range, 47-73) to 89.1 (range, 71-97; P = 0.009). The mean radiological angles were near normal, exhibiting significant improvements in the lateral talo-metatarsal and Djian-Annonier angles.

CONCLUSIONS

Arthroscopic resection of a TLAP is safe. In the short term, the restoration of subtalar mobility reduces pain, and improves instability and static disorders. Longer follow-up of a larger patient series is required.