Detection of radiographically occult ankle fractures following acute trauma: positive predictive value of an ankle effusion

Probability of Occult Ankle Fracture Based on Radiograph-Measured Swelling

INTRODUCTION

Pediatric ankle injuries are a common presentation in the emergency department (ED). A quarter of pediatric ankle fractures show no radiographic evidence of a fracture. Physicians often correlate non-weight bearing and tenderness with an occult fracture. We present this study to predict the probability of an occult fracture using radiographic soft-tissue swelling on initial ED radiographs.

METHODS

This is a retrospective study at a Level 1 pediatric trauma center from 2021 to 22. Soft-tissue swelling between the lateral malleolus and skin was measured on radiographs, and weight-bearing status was documented. Statistical analysis was conducted using Stata software.

DISCUSSION

The study period involved 32 patients with an occult fracture, with 8 (25%) diagnosed with a fracture on follow-up radiographs. The probability of an occult fracture was calculated as a function of the ankle swelling in millimeters (mm) using a computer-generated predictive model. False-negative and false-positive rates were plotted as a function of the degree of ankle swelling.

CONCLUSION

Magnitude of ankle soft-tissue swelling as measured on initial ED radiographs is predictive of an occult fracture. Although weight-bearing status was not a sign of occult fracture, it improves the predictive accuracy of soft-tissue swelling.

Imaging Review of Snowboard Injuries

Snowboarding and skiing remain the two most popular winter sports worldwide. Musculoskeletal (MSK) injuries are common in snowboarding, and the number has increased significantly since the advent of snow parks. The number of injuries is the highest for novice snowboarders; more experienced boarders generally sustain more severe injuries. Snowboarders can experience a wide array of MSK injuries, but some injury types are more frequently encountered because of the specific injury mechanism unique to snowboarding. This article reviews the most common snowboarding injuries with a focus on the current understanding of the injury mechanism and provides an approach to imaging.

Reporting errors in plain radiographs for lower limb trauma-a systematic review and meta-analysis

INTRODUCTION

Plain radiographs are a globally ubiquitous means of investigation for injuries to the musculoskeletal system. Despite this, initial interpretation remains a challenge and inaccuracies give rise to adverse sequelae for patients and healthcare providers alike. This study sought to address the limited, existing meta-analytic research on the initial reporting of radiographs for skeletal trauma, with specific regard to diagnostic accuracy of the most commonly injured region of the appendicular skeleton, the lower limb.

METHOD

A prospectively registered, systematic review and meta-analysis was performed using published research from the major clinical-science databases. Studies identified as appropriate for inclusion underwent methodological quality and risk of bias analysis. Meta-analysis was then performed to establish summary rates for specificity and sensitivity of diagnostic accuracy, including covariates by anatomical site, using HSROC and bivariate models.

RESULTS

A total of 3887 articles were screened, with 10 identified as suitable for analysis based on the eligibility criteria. Sensitivity and specificity across the studies were 93.5% and 89.7% respectively. Compared with other anatomical subdivisions, interpretation of ankle radiographs yielded the highest sensitivity and specificity, with values of 98.1% and 94.6% respectively, and a diagnostic odds ratio of 929.97.

CONCLUSION

Interpretation of lower limb skeletal radiographs operates at a reasonably high degree of sensitivity and specificity. However, one in twenty true positives is missed on initial radiographic interpretation and safety netting systems need to be established to address this. Virtual fracture clinic reviews and teleradiology services in conjunction with novel technology will likely be crucial in these circumstances.

Pelvic Shadowing as a Diagnostic Predictor of Orthopedic Pathology in Orthopedic Trauma Patients

Introduction

The Throckmorton sign, or John Thomas sign, is a well-established orthopedic eponym, anecdotally used in orthopedic surgery to correlate the direction of male genitalia, observed on a pelvic radiograph, with the laterality of an associated orthopedic pathology. In earlier studies, the direction of pelvic shadowing on X-ray has been neither a credible nor a reliable predictor of fracture laterality. Given this small body of evidence, we sought to further investigate the relationship between peri-trochanteric hip fracture laterality and male genitalia lie.

Method

A single-center retrospective chart review was conducted of 397 consecutive male patients who received pelvic radiographs performed upon entry to an urban level 1 trauma center. Exclusion criteria included age less than 18 years or a prior history of pelvic or urological surgery. Of this cohort, 360 patients met the inclusion criteria and underwent investigation.

Results

The study population had an average age of 42 years (range: 18-91 years). Statistical analysis yielded a 4.24 relative risk with pelvic shadowing laterality and respective peri-trochanteric hip fracture sidedness. Additionally, there was a 4.63 and 9.88 relative risk of tibial shaft fractures and distal radius fractures having a concomitant positive Throckmorton Sign, respectively.

Conclusion

Pelvic shadowing can be used as an additional diagnostic tool in predicting peri-trochanteric hip fracture sidedness in a trauma bay setting.

ACR Appropriateness Criteria® Acute Trauma to the Ankle

Acute injuries to the ankle are frequently encountered in the setting of the emergency room, sport, and general practice. This ACR Appropriateness Criteria defines best practices for imaging evaluation for several variants of patients presenting with acute ankle trauma. The variants include scenarios when Ottawa Rules can be evaluated, when there are exclusionary criteria, when Ottawa Rules cannot be evaluated, as well as specific injuries. Clinical scenarios are followed by the imaging choices and their appropriateness with an accompanying narrative explanation to help physicians to order the most appropriate imaging test. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

[Fractures of the anterior process of the calcaneus-frequently overlooked injuries following ankle sprains]

Fractures to the anterior process of the calcaneus (PAC) have long been considered rare injuries and have received little attention in clinical research. On the contrary, recent studies have reported a distinct higher incidence, especially following ankle sprains. Decisive reasons are that fractures of the PAC are regularly missed on plain radiographs and that a clinical differentiation from injuries to the lateral ankle ligaments is difficult. With the broad availability of cross-sectional imaging modalities fractures of the PAC are diagnosed more frequently and more reliably. The purpose of this review is to give an overview on the diagnostics, classification and treatment recommendations to this topic and discuss the studies available. To date no evidence-based recommendations are available for the treatment of fractures of the PAC. The few case reports and case series published, predominantly recommend conservative treatment; however, the treatment regimens vary considerably, ranging from immobilization in a lower leg cast (2-10 weeks) to early functional treatment with full weight-bearing. The surgical treatment by open reduction and internal fixation has been described primarily for large dislocated fractures. Surgical excision is considered mainly in cases of persistent pain or symptomatic non-union following non-operative treatment. For both, non-operative and operative treatment, the case reports and case series report satisfactory outcomes for the majority of patients. Nevertheless, comparative studies and patient-rated outcome measures are missing. Therefore, evidence-based recommendations cannot be given.

ACR Appropriateness Criteria acute trauma to the ankle

Acute ankle injuries are frequently diagnosed and treated in emergency departments and outpatient clinics. Recent evidence-based clinical treatment guidelines and systematic review of economic analyses support the use of 3-view (anteroposterior, lateral, and mortise) radiographic evaluation of patients meeting the criteria of the Ottawa ankle rules. Cross-sectional imaging has a limited secondary role primarily as a tool for preoperative planning and as a problem-solving technique in patients with persistent symptoms and suspected of having occult fractures. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Pediatric emergency physician opinions on ankle radiograph clinical decision rules

OBJECTIVES

The Low Risk Ankle Rule (LRAR) is a validated clinical decision rule (CDR) about the indications for ankle radiographs in children with acute blunt ankle trauma. Although application of the LRAR has the potential to safely reduce the rate of ankle radiography by 60%, current x-ray rates in most emergency departments (EDs) in the United States and Canada remain unnecessarily high (85%-100%). To evaluate this gap between knowledge and practice, physicians who treat pediatric ankle injuries in EDs were surveyed to determine physician awareness and use of the LRAR, acceptability of the LRAR as measured by the Ottawa Acceptability for Decision Rules Scale (OADRS), and perceived barriers to the use of a validated pediatric ankle x-ray rule.

METHODS

An on-line survey of members of two national pediatric emergency medicine (PEM) physician associations in the United States and Canada was conducted using a modified Dillman technique.

RESULTS

Response rates were 75.6% (149/197) in Canada and 45.7% (352/770) in the United States, yielding an aggregate rate of 51.8%. Only 119 of 478 respondents (24.9%) had heard of the LRAR, and 53 of 432 (12.3%) were sufficiently familiar with the LRAR to apply it. The LRAR scored a mean (+/- standard deviation [SD]) OADRS score of 4.28 out of 6 (+/-0.67), comparable to published OADRS scores for two well-known CDRs used in adults. Of the respondents, 434 of 471 (92.1%) at least "slightly agreed" that ankle x-ray CDRs would be useful in their practice, with no significant differences between the two sides of the border (p = 0.28). Ankle x-ray rules were felt to save time by 342 (72.6%) of the participants, and the pediatric ankle exam was considered easy enough to apply a CDR by 306 (65.0%). The most common barriers reported for use of any ankle x-ray rule included perceived reduction in family satisfaction without imaging in 380 (80.7%), nurse-initiated x-ray protocols not based on ankle x-ray rules in 285 (60.5%), concerns about missing a significant fracture in 248 (52.7%), and a preference for own clinical judgment in 246 (52.2%).

CONCLUSIONS

Although the LRAR had a high acceptability score among respondents in this survey, this validated CDR is not widely known and is even less frequently applied by PEM physicians in the United States and Canada. Barriers were identified that will guide efforts to improve the knowledge translation of the LRAR into pediatric EDs.

Occult fractures of extremities

Recent advances in cross-sectional imaging, particularly in CT and MR imaging, have given these modalities a prominent role in the diagnosis of fractures of the extremities. This article describes the clinical application and imaging features of cross-sectional imaging (CT and MR imaging) in the evaluation of patients who have occult fractures of the extremities. Although CT or MR imaging is not typically required for evaluation of acute fractures, these modalities could be helpful in the evaluation of the occult osseous injuries in which radiographic findings are equivocal or inconclusive.

Diagnosis and imaging of ankle instability

Ankle instability is a major cause of symptoms following an ankle sprain. With a thorough history and examination, appropriate additional investigations, including cross-sectional imaging, and thoughtful interpretation of the information, one should rarely be caught out by misdiagnosis, multiple diagnoses, or unusual causes.

The Bernese Ankle Rules: A Fast, Reliable Test after Low-Energy, Supination-Type Malleolar and Midfoot Trauma

BACKGROUND

Trauma of the midfoot and ankle joint are among the most commonly treated injuries in the emergency unit. The "Ottawa ankle rules" were introduced in 1992 to lower the amount of radiographs based on a standardized clinical examination. The weakness of the "rules" is the low specificity reported in several clinical studies.

METHOD

We introduced a new indirect stress technique to examine the ankle and the midfoot after low-energy, supination-type trauma, avoiding direct palpation of the injured region.

RESULTS

In 354 prospectively documented patients, the Bernese ankle test produced a sensitivity of 100% and a specificity of 91%.

CONCLUSION

Compared with the original Ottawa ankle rules, the number of false-positive findings could be significantly reduced, resulting in a reduction of 84% in radiographs after low-energy, supination-type trauma ankle and midfoot trauma. Further investigations have to be performed to prove whether these findings are reproducible within other clinical settings, which could result in major cost savings for the health care system.

Imaging of fractures of the lateral process of the talus, a frequently missed diagnosis

Although if fractures of the lateral process of the talus (LPT) have been considered rare the widespread diffusion in snowboard practice has resulted in a dramatic increase in their frequency. If unrecognized they can result in secondary osteoarthritis of the ankle and/or talo-calcaneal joints and chronic pain and stiffness. Due to the complex anatomy of the region, these fractures are difficult to detect by standard radiographs. A high degree of suspicion is then necessary to diagnose them. Once suspected on the basis of physical examination and/or non concluding radiographs, computed tomography (CT) is the best modality to confirm the diagnosis and accurately appreciate the number of the fragments and their position which have therapeutic consequences (medical vs. surgical treatment). A better knowledge of these lesions seems necessary to the general radiologist to allow an early diagnosis in order to avoid chronic sequel. The purpose of this article is to report three additional cases of LPT fractures and discuss their pathogenesis, diagnosis and treatment.

Evaluation of the patient with extremity trauma: an evidence based approach

This article reviews relevant literature to provide evidence based guidelines for the evaluation of patients with extremity trauma in the emergency department. The development of clinical decision rules for extremity trauma in the ankle and knee, and guidelines for obtaining postreduction radiographs of shoulder dislocations and nursemaid's elbows are discussed.

Magnetic resonance imaging of the musculoskeletal system: part 7. The ankle

Diagnosis of many traumatic or attritional lesions about the ankle may be difficult with only the history, physical examination, and conventional radiographs. When uncertainty is present clinically or when precise depiction of the extent of injury will assist with treatment planning, magnetic resonance imaging may be a useful adjunct to these basic methods of evaluation. In particular, magnetic resonance imaging is useful for the identification and evaluation of tendinitis, tendon dislocations, osteochondral lesions, and occult fractures. Additional clinical settings in which magnetic resonance imaging may be helpful include evaluation of tumors, osteomyelitis, and tarsal coalition.

Improving the detection of radiographically occult ankle fractures: positive predictive value of an ankle joint effusion

OBJECTIVE

To assess the value of an ankle effusion on plain radiographs as a predictor of radiographically occult fracture after acute ankle trauma.

PATIENTS

Consecutive patients with acute ankle trauma and radiographic evidence of an ankle joint effusion. Patients were excluded if ankle trauma was sustained more than 48 h previously or if a fracture was visible on initial photographs.

METHODS

All subjects (n = 26) underwent computed tomography (CT) of the ankle in sagittal and coronal planes. Ankle effusion size was measured from initial lateral ankle radiographs.

RESULTS

Twelve patients (46%) had radiographically occult fractures identified with CT. Fracture sites included: posterior or lateral malleoli (n = 4), calcaneus (n = 1), or talus (n = 7). Ankle effusion size was 11.2 mm in the group without fracture and 17.1 mm in the group with fracture (P < 0.0001). The positive predictive value of an effusion 15 mm or greater was 83%. CT detected significant soft-tissue injuries in four (15%) patients including peroneal retinaculum tear (n = 1), anterior talofibular ligament avulsion (n = 1), and tears of the peroneus longus (n = 1) and tibialis posterior (n = 1) tendons.

CONCLUSIONS

The presence of a large ankle effusion of radiographs after acute ankle trauma suggests an underlying fracture. An ankle effusion of > or = 15 mm is a reasonable threshold to prompt additional imaging. Computed tomography provides good visualization of subtle bone injuries and may detect clinically imported soft-tissue injuries.

Occult ankle fracture detected by an ankle effusion on plain radiography: a case report

Subtle ankle fractures may escape detection on plain radiography. These occult fractures can cause prolonged disability and pain. We present a case of blunt ankle trauma where plain radiography failed to reveal any bony abnormalities. The recognition of an ankle effusion on plain radiographs prompted us to perform a computed tomography (CT) scan of the ankle. The CT scan demonstrated an anterior plafond fracture of the distal tibia, which required surgical fixation. Had the fracture not been identified, our patient would have been treated inappropriately for a ligament sprain. An occult fracture should be suspected if an ankle is grossly swollen after blunt trauma, and plain radiography demonstrates an effusion. In this circumstance, performance of further imaging studies, such as conventional or CT, are advised to rule out an occult ankle fracture.