Imaging of athletic injuries to the ankle and foot

"Haleem’s Hen"; A mnemonic for the anatomy of hindfoot structures at the level of sustentaculum tali on coronal T1-weighted magnetic resonance images

Magnetic resonance anatomy of the hindfoot as seen at the level of the sustentaculum tali is intricate due to surrounding muscles, tendons, aponeurosis and ligaments. The objective of this work is to provide a mnemonic with illustrative figures to simplify this complex anatomical region on coronal T1-weighted MR images (T1-MRIs).

One hundred and twenty-four patients referred for foot and ankle complaints were scanned utilizing standard MRI imaging protocols for depiction of the hindfoot. Only coronal T1-MRIs of the calcaneus at the level of sustentaculum tali of unremarkably reported patients were selected for this work.

Upon viewing the calcaneus with the adjacent anatomical structures on coronal T1-MRIs, the overall appearance resembles a “Hen in the Nest with Four Eggs’’. The calcaneus represents the body of the hen, while the sustentaculum tali forms the head and neck. The posterior tibial tendon represents the crest of the hen, and the flexor digitorum longus and flexor hallucis longus tendons represent its beak and wattle, respectively. The peroneus brevis and peroneus longus tendons represent the tail, and the long plantar ligament represents the flexed legs of Haleem’s hen. The plantar aponeurosis represents the hen’s nest. Whereas the abductor hallucis, flexor digitorum brevis, abductor digiti minimi and quadratus plantae muscles are the four eggs.

The mnemonic, “Haleem’s Hen in the Nest with Four Eggs”, serves as a simplified phrase for radiologists and orthopedic surgeons to easily recall the anatomy of the hindfoot when viewing it at the level of the sustentaculum tali on coronal T1-MRIs.

High incidence of osteochondral lesions after open reduction and internal fixation of displaced ankle fractures: Medium-term follow-up of 100 cases

BACKGROUND

The incidence of osteochondral lesions (OCLs) in association with displaced ankle fractures has only been examined in two previous studies. In both studies magnetic resonance imaging (MRI) was performed prior to open reduction and internal fixation (ORIF). Because MRI may overdiagnose or overestimate the extent of OCLs in an acute trauma setting the aim of this study was to determine the incidence of OCLs after ORIF of displaced ankle fractures using MRI at medium-term follow-up, and to analyse if the severity of fracture or the clinical outcome correlates with the incidence of OCLs.

PATIENTS AND METHODS

Following institutional review board approval a total of 100 patients (mean age, 41.3 years; range, 17.9-64.3 years) with a displaced ankle fracture who had undergone ORIF according to the AO principles were included in this study. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to quantify the clinical outcome and MR images were evaluated for OCLs of the talus and distal tibia after a mean of 34.5 months (range, 17.5-54.1 months).

RESULTS

OCLs were found in 40.4% of the patients. Logistic regression revealed a significant correlation between the severity of fracture and the incidence of OCLs. Patients with a trimalleolar fracture (p=0.04) or an ankle fracture dislocation (p=0.003) had a significantly higher risk for developing an OCL compared to those with a type B fracture. Logistic regression also demonstrated a significant correlation between the clinical outcome (AOFAS score) and the incidence of OCLs (p=0.01). The risk for developing an OCL increases up to 5.6% when the AOFAS score decreases by one point.

CONCLUSION

OCLs were frequently found in association with acute ankle fractures at medium-term follow-up, and the severity of fracture was associated with an increased number of OCLs. Considering the disadvantages of MRI including the high cost and limited availability, the results of this study may help to explain why anatomic surgical realignment of displaced ankle fractures may still be associated with poor clinical outcomes.

Diagnostic accuracy of 3.0 Tesla magnetic resonance imaging for the detection of articular cartilage lesions of the talus

BACKGROUND

Talar chondral defects can be a source of persistent ankle pain and disability. If untreated, there is an increased risk of osteoarthritis. The purpose of our study was to determine diagnostic accuracy of 3T MRI in detecting Outerbridge grades 3 and 4 articular cartilage lesions of the talus in a clinical setting, utilizing a standardized clinical MRI protocol.

METHODS

Patients who had a 3T ankle MRI and subsequent ankle surgery, by a single surgeon, were included in this study. MRI exams were performed 180 days or less before surgery. Seventy-nine ankles in 78 patients (mean age of 42.3 years) were included in this study. Mean body mass index was 26.3. A standard clinical MRI exam was performed on a 3T MRI scanner. Mean days from MRI to surgery was 39 days. All MRI exams were read and findings recorded by a musculoskeletal radiologist. Arthroscopic examination was performed by a single orthopaedic surgeon. Detailed arthroscopic findings and demographic data were collected prospectively and stored in a data registry. Of the 78 patients, 31 (39.2%) reported previous ankle surgery. Pain was the primary reason for seeking medical attention as reported by 95% of patients, followed by instability in 44% and loss of function with 42%.

RESULTS

Prevalence of Outerbridge grade 3 and 4 talar articular cartilage defects identified at arthroscopy was 17.7%. The 3T MRI demonstrated a sensitivity of 0.714, specificity of 0.738, positive predictive value of 0.370, and negative predictive value of 0.923.

CONCLUSION

Sensitivity and specificity levels were acceptable for detection of grades 3 and 4 articular cartilage defects of the talar dome using 3T MRI. The high negative predictive value may be beneficial in preoperative planning. While these values are acceptable, a high index of suspicion should be maintained in the appropriate clinical setting.

Sideline coverage: when to get radiographs? A review of clinical decision tools

CONTEXT

Sidelines coverage presents unique challenges in the evaluation of injured athletes. Health care providers may be confronted with the question of when to obtain radiographs following an injury. Given that most sidelines coverage occurs outside the elite level, radiographs are not readily available at the time of injury, and the decision of when to send a player for radiographs must be made based on physical examination. Clinical tools have been developed to aid in identifying injuries that are likely to result in radiographically important fractures or dislocations.

EVIDENCE ACQUISITION

A search for the keywords x-ray and decision rule along with the anatomic locations shoulder, elbow, wrist, knee, and ankle was performed using the PubMed database. No limits were set regarding year of publication. We selected meta-analyses, randomized controlled trials, and survey results. Our selection focused on the largest, most well-studied published reports. We also attempted to include studies that reported the application of the rules to the field of sports medicine.

STUDY DESIGN

Retrospective literature review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

The Ottawa Foot and Ankle Rules have been validated and implemented and are appropriate for use in both pediatric and adult populations. The Ottawa Knee Rules have been widely studied, validated, and accepted for evaluation of knee injuries. There are promising studies of decision rules for clinically important fractures of the wrist, but these studies have not been validated. The elbow has been evaluated with good outcomes via the elbow extension test, which has been validated in both single and multicenter studies. Currently, there are no reliable clinical decision tools for traumatic sports injuries to the shoulder to aid in the decision of when to obtain radiographs.

CONCLUSION

Clinical decision tools have been developed to aid in the diagnosis and management of injuries commonly sustained during sporting events. Tools that have been appropriately validated in populations outside the initial study population can assist sports medicine physicians in the decision of when to get radiographs from the sidelines.

SPECT/CT in the management of osteochondral lesions of the talus

BACKGROUND

The treatment of osteochondral lesion of the talus (OLT) is mainly based upon the stage of the disease so accurate imaging is crucial. SPECT/CT combines bone scan with high-resolution CT and can provide functional-anatomical images in a single stage. The purpose of this study was to assess the value of SPECT/CT in the management of OLT.

MATERIALS AND METHODS

From 2004 to 2009, 22 patients with OLT were identified that had both SPECT/CT and MRI of the foot and ankle. All charts were reviewed to ascertain the reason for ordering the SPECT/CT and the additional information obtained. AOFAS outcome scores were calculated at the time of followup.

RESULTS

Twelve patients underwent ankle arthroscopy for debridement or drilling of the osteochondral lesion. The mean AOFAS score in these 12 patients was 83.6. SPECT/CT helped preoperative planning by identifying the exact location of the active lesion, especially in multifocal disease or revision surgeries while showing the depth of the active lesion. Ten patients had conservative management due to minimal or no activity over the lesion on SPECT/CT images. The mean AOFAS score in these ten patients was 78.8 which was comparable to the operative group.

CONCLUSION

We believe SPECT/CT was able to provide additional diagnostic value by demonstrating a co-existing pathology as a potential cause of pain and in preoperative planning by showing the depth of activity and the precise location of the active segment in multiple lesions.

A regional approach to foot and ankle MRI

This chapter presents a regional anatomic approach to MRI applications in the foot and ankle. From a clinical perspective, patients often describe their symptoms in terms of the part of the foot that hurts and when and how it hurts. Clinical questioning and physical diagnosis pursue this line as well, trying to narrow down the diagnostic possibilities. There are conditions that may blur the anatomic distinctions for forefoot, midfoot, rearfoot, and ankle; involve more than one region of the foot simultaneously; or occur in any area of the foot. The chapter also includes a separate section on the presentations of inflammatory arthritides in foot and ankle joints.

Orthopedic trauma: office management of major joint injury

Orthopedic injuries are common reasons for visits to primary care physicians. Careful history and physical examination with intelligent use of imaging technology will arrive at the correct diagnosis in most patients. Many conditions may be definitively managed by the office internist. Others maybe initially stabilized and referred to orthopedic surgeons for definitive care. Nondisplaced fractures, tendon injuries, sprains, and overuse syndromes are entities within the purview of the primary care physician. Familiarity and confidence with diagnosis and management of these conditions in the office is optimal for the care of the adult patient.

Imaging of the calcaneus

The anatomy of the calcaneus is complex with multiple processes and grooves for support of related bony and soft tissue structures. With respect to imaging, the calcaneus and its articulations are a diagnostic challenge to radiologists and clinicians. This article focuses on the use of commonly employed radiologic modalities with respect to the anatomy of the calcaneus and some of the more common and challenging conditions that affect the calcaneus.

The Flexor Hallucis Longus: Tenographic Technique and Correlation of Imaging Findings with Surgery in 39 Ankles

PURPOSE

To examine the use of tenography for evaluation of the flexor hallucis longus (FHL) sheath.

MATERIALS AND METHODS

Institutional review board approval was waived, patient consent was obtained, and the study was HIPAA compliant. Retrospective review of 192 FHL tenograms and associated surgical records identified 39 ankles in 37 patients (17 male, 20 female; mean age +/- standard deviation, 38 years +/- 13.8; range, 14-68 years) in which both tenography and surgery had been performed. Two radiologists reviewed tenographic findings, including contrast agent extravasation, synovial irregularity, stenosis, fibrous bands, sheath outpouching, extent of opacification, and communications with adjacent structures. Alterations in pain after anesthesia of the tendon sheath were also recorded. Surgical reports were reviewed.

RESULTS

Thirty-four of 39 tenograms were diagnostic. Some extravasation occurred in nine (45%) of 20 injections with an initial injection method and in two (11%) of 19 with a new injection technique. Synovial irregularity was present in all 34 studies (15 mild, 16 moderate, three severe). Stenoses were identified in 23 (68%) of 34 ankles, fibrous bands were seen in 16 (47%) of 34 ankles, and outpouching of the sheath above a stenosis was present in 13 (38%) of 34 ankles. Communication of the FHL sheath with the ankle, flexor digitorum longus, or subtalar joint occurred in half the cases. Most patients with pain reported relief; relief was complete (100% reduction from preprocedural pain) in eight of 27, moderate (50%-90% reduction) in nine of 27, and mild (<50% reduction) in eight of 27 patients.

CONCLUSION

Tenography of the FHL sheath produced diagnostic images in almost all patients and effectively demonstrated abnormalities of the tendon sheath. Pain relief with anesthetic injection helped confirm the FHL sheath as the pain generator.

Ankle MR Arthrography: How, Why, When

MR arthrography has become an important tool for the assessment of a variety of ankle disorders. MR arthrography may facilitate the evaluation of patients with suspected intra-articular pathology in whom conventional MR imaging is not sufficient for an adequate diagnosis and be useful for therapy planning. MR arthrography is valuable in the evaluation of ligamentous injuries, impingement syndromes, cartilage lesions, osteochondral lesions of the talus, loose bodies, and several synovial joint disorders. Indirect MR arthrography is a useful adjunct to conventional MR imaging and may be preferable to direct MR arthrography in cases in which an invasive procedure is contraindicated or when fluoroscopy is not available.

Ankle and Foot Injuries in Pediatric and Adult Athletes

Foot and ankle injuries are among the most common in athletes.Differential diagnosis, imaging decisions, and treatment plan should be influenced by the age of the athlete. A thorough history and physical examination, with an understanding of the anatomy of the foot and ankle anatomy and the mechanism of injury, will give the best opportunity to make the correct diagnosis. For most athletes, the prognosis for returning to play after a foot or ankle injury is very good. The recipe for keeping our athletes healthy includes early intervention, undergoing proper rehabilitation, applying braces or orthotics when indicated, and preventing injuries when appropriate.

Prospective study on diagnostic strategies in osteochondral lesions of the talus

Our aim in this prospective study was to determine the best diagnostic method for discriminating between patients with and without osteochondral lesions of the talus, with special relevance to the value of MRI compared with the new technique of multidetector helical CT. We compared the diagnostic value of history, physical examination and standard radiography, a 4 cm heel-rise view, helical CT, MRI, and diagnostic arthroscopy for simultaneous detection or exclusion of osteochondral lesions of the talus. A consecutive series of 103 patients (104 ankles) with chronic ankle pain was included in this study. Of these, 29 with 35 osteochondral lesions were identified. Twenty-seven lesions were located in the talus.

Our findings showed that helical CT, MRI and diagnostic arthroscopy were significantly better than history, physical examination and standard radiography for detecting or excluding an osteochondral lesion. Also, MRI and diagnostic arthroscopy performed better than a mortise view with a 4 cm heel-rise. We did not find a statistically significant difference between helical CT and MRI. Diagnostic arthroscopy did not perform better than helical CT and MRI for detecting or excluding an osteochondral lesion.

MRI of sports-related injuries of the foot and ankle: part 1

The ankle is one of the most frequently injured joints in the course of sports activities. MR imaging has become the modality of choice in the evaluation of most of these lesions, especially in competitive athletes. The purpose of this article is: (1) To illustrate the MR imaging features of a great number of sports-related injuries of the ankle, correlating it with lesional mechanisms and clinical findings, and (2) To review the role of MR imaging in clinical management and surgical planning of these injuries, especially in competitive athletes. In order to a better understanding of these lesions, a classification based on the anatomic origin are outlined. The spectrum of injuries has been classified in: (1) osseous lesions, (2) ligamentous injuries, (3) tendinous lesions, (4) impingement impingement, and (5) plantar fascial lesions.