MRI of the foot and ankle

Magnetic Resonance Imaging Findings and Potential Anatomic Risk Factors for Anterolateral Ankle Impingement in Children and Adolescents Suffering from Non-Overload Atraumatic Ankle Pain

BACKGROUND/OBJECTIVES

To assess magnetic resonance image (MRI) findings in children and adolescents with atraumatic non-overload ankle pain and to identify potential anatomic risk factors.

METHODS

In total, 310 MRIs of 6- to 20-year-old patients were evaluated regarding detectable ankle pathologies. A total of 147 patients (68 males; 79 females) suffered from atraumatic non-overload ankle pain. The findings were compared to a control group (163 patients: 89 males; 74 females), including patients with ankle trauma in the 4 weeks prior to MRI examination. A t-test for unpaired samples and a binary logistic regression model were used to identify significant differences between both groups and determine potential anatomic risk factors.

RESULTS

In the group with atraumatic ankle pain, 95 patients (64.6%) showed at least one pathology. Anterolateral impingement of the upper ankle joint was found in 29 patients (19.7%). Its occurrence was significantly higher in atraumatic non-overload patients than in the control group (p = 0.043). Moreover, a significant correlation between anterolateral impingement of the upper ankle and the presence of hindfoot valgus malposition (n = 25; 17.0%) could be proven in atraumatic non-overload patients (p = 0.035).

CONCLUSIONS

Anterolateral impingement of the upper ankle joint is frequently observed in children and adolescents suffering from atraumatic non-overload ankle pain, whereby a hindfoot valgus malposition seems to present an anatomic risk factor.

Heel pain caused by os subcalcis: A case report

BACKGROUND

The accessory bones are common bone variations around the feet and ankles, which usually originate from nonunion of the secondary ossification center adjacent to the main bone mass, and most of them remain asymptomatic. Os subcalcis is an accessory bone at the plantar aspect of the calcaneus, which is located just posterior to the insertion of the plantar fascia. Focal bone formation at the calcaneal plantar pole with heel pain has rarely been reported.

CASE SUMMARY

A 55-year-old man presented to our clinic with left plantar heel pain and a progressive swelling for 8 years. X-ray, computer tomography and magnetic resonance imaging showed a large os subcalcison the plantar side of the calcaneus, located at the insertion of the plantar fascia. He underwent surgical excision of the lesion. Microscopically the bony trabeculae were intermingled with fat and covered with cartilage.

CONCLUSION

This is a rare case with accessory os subcalcis leading to heel pain. It highlights the awareness of os subcalcis and helps avoid future misdiagnosis of heel pain.

Ilizarov Technique in Severe Pediatric Foot Disorders

The treatment of foot disorders in pediatric age with Ilizarov method is reserved for complex cases, cases in which it is not possible to perform acute corrections or cases that need bone and soft-tissue lengthening. Ilizarov method permits to correct any deformity. Correction can be achieved progressively with a closed procedure or combining the external fixator with a treatment involving soft or bone tissues. Complications are frequent; however, most of them do not affect the outcome of the treatment.

Dynamic high-resolution US of ankle and midfoot ligaments: normal anatomic structure and imaging technique

The ankle is the most frequently injured major joint in the body, and ankle sprains are frequently encountered in individuals playing football, basketball, and other team sports, in addition to occurring in the general population. Imaging plays a crucial role in the evaluation of ankle ligaments. Magnetic resonance imaging has been proven to provide excellent evaluation of ligaments around the ankle, with the ability to show associated intraarticular abnormalities, joint effusion, and bone marrow edema. Ultrasonography (US) performed with high-resolution broadband linear-array probes has become increasingly important in the assessment of ligaments around the ankle because it is low cost, fast, readily available, and free of ionizing radiation. US can provide a detailed depiction of normal anatomic structures and is effective for evaluating ligament integrity. In addition, US allows the performance of dynamic maneuvers, which may contribute to increased visibility of normal ligaments and improved detection of tears. In this article, the authors describe the US techniques for evaluation of the ankle and midfoot ligaments and include a brief review of the literature related to their basic anatomic structures and US of these structures. Short video clips showing dynamic maneuvers and dynamic real-time US of ankle and midfoot structures and their principal pathologic patterns are included as supplemental material. Use of a standardized imaging technique may help reduce the intrinsic operator dependence of US. Online supplemental material is available for this article.

MRI evaluation of the MTP plantar plates compared with arthroscopic findings: a prospective study

BACKGROUND

Instability of the lesser metatarsophalangeal (MTP) joints has been widely reported and plantar plate insufficiency is a key part of this pathologic process. The diagnosis is made clinically but can be aided by imaging studies, particularly magnetic resonance imaging (MRI); however, the sensitivity and accuracy of this method compared to direct visualization of these lesions has not yet been established, nor has interobserver accuracy of MRI been assessed for evaluation of plantar plate pathology. In this study, our goals were to identify the accuracy of the MRI in describing plantar plate tears when compared to direct arthroscopic visualization using an anatomic grading system and to test the influence of an anatomic grading system in the accuracy of the MRI readings.

METHODS

We evaluated the clinical exam, MRI scans, and arthroscopic findings of 35 patients with lesser MTP instability.

RESULTS

Using an anatomic grading system, a distinct improvement in the radiological evaluation and interpretation occurred. Knowledge of the pattern of plantar plate tears by a radiologist enabled them to locate and describe the type of tears of the plantar plate on the MRI. The amount of training and the experience of the radiologist were also important factors in our study. The senior radiologists had much better levels of accuracy (Group A, 77.0%; Group B, 88.5%) than less experienced radiologists.

CONCLUSION

Prior knowledge of the pathophysiology and morphological types of lesions of the plantar plates was helpful for accurate identification and description of the tears by the radiologist.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Ankle sprain complications: MRI evaluation

Sprains are disruptions of the ligamentous anatomy about a joint. The ankle sprain is one of the most common injuries seen in podiatric and orthopedic practice. It usually is incurred from an inversion force on the ankle, but eversion forces also can traumatize the ankle. Many times, this injury is taken for granted because of the frequency of its presentation. The patient usually is given appropriate initial care, but the patient can experience continued or residual pain. Podiatrists have found this problem is common and have come to recognize that secondary or accessory injuries occur that slow the natural recovery of this injury.

Sonography of Plantar Plates in Cadavers: Correlation with MRI and Histology

OBJECTIVE

The purpose of our study was to describe the sonographic appearance of the lesser metatarsal plantar plates in cadavers and to correlate these findings with MRI and histology.

MATERIALS AND METHODS

Six soft-embalmed cadaveric feet (74-92 years old; two male, one female) were imaged with sonography and MRI. Tear dimensions of the plantar plate were recorded in the long and short axes. Orthopedic surgeons directly inspected the plantar plates before removing samples for histologic correlation. One young fresh cadaver was imaged with sonography before histologic assessment.

RESULTS

The normal plantar plate appearance on sonography was a slightly echoic, homogeneous, curved structure. At direct inspection, a tear was present in 23 (96%) of 24 of the lesser plantar plates in the soft-embalmed feet. This direct inspection correlated with sonography detecting 23 tears correctly and MRI, 22 tears. Both sonography and MRI falsely reported one tear, but MRI also failed to detect one tear. Histologically, the abnormal plantar plate showed loss of the normal dense regular tissue and replacement with vessels, hydropic tissue, and a mixture of loose connective tissue and dense irregular connective tissue.

CONCLUSION

Sonography, being noninvasive, shows promise as an imaging tool of the plantar plate. With ongoing research in this area we hope to determine the reliability and significance of such a technique in the evaluation of the plantar plate.

Protocols in sports magnetic resonance imaging

Magnetic resonance imaging, with its multiplanar imaging capability and superior soft-tissue contrast, has become the preferred method for imaging sports-related injuries. Advances in gradient technology, receiver coils, and imaging software have allowed the imaging of the injured athlete to take place quickly and at high resolution. Understanding the tissues being imaged, the underlying anatomy, and the capabilities of today's scanners is crucial to the design of intelligent and efficient protocols.

Magnetic resonance imaging of the foot and ankle

Magnetic resonance (MR) imaging of the foot and ankle is playing an increasingly important role in the diagnosis of a wide range of foot and ankle abnormalities, as well as in planning for their surgical treatment. For an optimal MR study of the foot and ankle, it is necessary to obtain high-resolution, small-field-of-view images using a variety of pulse sequences. The most common indication for MR imaging of the foot and ankle is for the evaluation of tendon and bone abnormalities, such as osteomyelitis, occult fractures, and partial and complete tears of the Achilles, tibialis posterior, and peroneal tendons. Magnetic resonance imaging has also been shown to be helpful in the diagnosis of several soft-tissue abnormalities that are unique to the foot and ankle, such as plantar fasciitis, plantar fibromatosis, interdigital neuromas, and tarsal tunnel syndrome.