Anatomic Relationship and Imaging Relevance of the Perforating Branches of the Peroneal Vessels to the Anterior Talofibular Ligament.

BACKGROUND: Patients frequently present to the emergency department after ankle injuries, and the anterior talofibular ligament (ATFL) is commonly damaged. Musculoskeletal ultrasound (US) can help to make a rapid diagnosis. There is a paucity of literature describing techniques to image the ATFL with US, and the complex ankle anatomy and potential pitfalls make imaging challenging. OBJECTIVE: Our aim was to estimate prevalence of perforating branches (PBs) of the peroneal vessels and determine their most frequent position relative to the ATFL. If these vessels are located in a predictable position at the level of the ATFL, they may serve as a sonographic landmark for the correct imaging plane. METHODS: Magnetic resonance imaging (MRI) scans of 105 ankles were reviewed to determine the PB prevalence and location at the ATFL. Inter-observer agreement was determined. Additionally, 16 ankles from 8 asymptomatic subjects were scanned using a high-frequency linear transducer and PB prevalence and location were noted. RESULTS: By MRI, PBs were detected in 85% of the ankles and 93% of ankles after consensus. In 73% of cases with agreed PB visualization, vessels assumed a medial position with respect to the ATFL. By US, PBs could be seen in 100% of cases, with the arterial PB seen in 81% of cases and assuming a medial position in 88%. CONCLUSIONS: PBs are often present, have a predictable course, and may be useful to help optimize US probe positioning when assessing the ATFL.

Association between tears of the posterior root of the medial meniscus and far posterior femoral condyle osteoarthritis.

PURPOSE: We aimed to evaluate whether tears of the posterior horn of the medial meniscus root ligament (PHMM RL) are associated with osteoarthritis of the far posterior femoral condyles (FPFC). METHODS: Retrospective review of 1158 patients who underwent arthroscopy identified 49 patients with confirmed tears of the medial meniscus posterior root ligament attachment. Preoperative magnetic resonance imaging (MRI) studies were reviewed to identify advanced osteoarthritis involving the medial and lateral FPFC. Control patients (n=48) had no meniscal tears confirmed by arthroscopy. Cases and controls were age- and sex-matched exactly 1:1. One case patient was excluded since there was no age- and sex-matched control available. The International Cartilage Research Society (ICRS) MRI cartilage grade was recorded for the medial and lateral FPFC. Associations were evaluated using univariate and multivariable conditional logistic regression analyses. RESULTS: There were 48 case and 48 control patients (10 men in each group, 20.8%) with median age 53 years (range, 21-67). Medial FPFC ICRS Grade 2 or higher lesions were present in 34 (70.8%) of case patients and 16 (33.3%) of control patients. Lateral FPFC ICRS Grade 2 or higher lesions were present in 24 (50%) of case patients and 14 (28.2%) of control patients. Increased body mass index (BMI) was associated with PHMM RL tears (OR=1.11, 95% CI [1.01, 1.22], P = 0.020). MRI was 81.2% (39/48) sensitive and 91.2% (44/48) specific for detection of PHMM RL tears. PHMM RL tears were associated with Grade 2 or higher medial FPFC osteoarthritis (OR=10.00, 95% CI (2.34, 42.78), P < 0.001). This association remained after adjusting for BMI (OR=11.79, 95% CI [2.46, 56.53], P = 0.002). There was also an association between PHMM RL tears and lateral FPFC osteoarthritis, which persisted after adjusting for BMI (OR =3.00, 95% CI [1.07, 8.37], P = 0.036). CONCLUSION: PHMM RL tears are associated with advanced osteoarthritis of the FPFC. Radiologists identifying FPFC osteoarthritis should look carefully for PHMM RL tears.

Yield of computed tomography of the cervical spine in cases of simple assault.

BACKGROUND: Computed tomography (CT) of the cervical spine (C-spine) is routinely ordered for low-impact, non-penetrating or "simple" assault at our institution and others. Common clinical decision tools for C-spine imaging in the setting of trauma include the National Emergency X-Radiography Utilization Study (NEXUS) and the Canadian Cervical Spine Rule for Radiography (CCR). While NEXUS and CCR have served to decrease the amount of unnecessary imaging of the C-spine, overutilization of CT is still of concern. METHODS: A retrospective, cross-sectional study was performed of the electronic medical record (EMR) database at an urban, Level I Trauma Center over a 6-month period for patients receiving a C-spine CT. The primary outcome of interest was prevalence of cervical spine fracture. Secondary outcomes of interest included appropriateness of C-spine imaging after retrospective application of NEXUS and CCR. The hypothesis was that fracture rates within this patient population would be extremely low. RESULTS: No C-spine fractures were identified in the 460 patients who met inclusion criteria. Approximately 29% of patients did not warrant imaging by CCR, and 25% by NEXUS. Of note, approximately 44% of patients were indeterminate for whether imaging was warranted by CCR, with the most common reason being lack of assessment for active neck rotation. CONCLUSIONS: Cervical spine CT is overutilized in the setting of simple assault, despite established clinical decision rules. With no fractures identified regardless of other factors, the likelihood that a CT of the cervical spine will identify clinically significant findings in the setting of "simple" assault is extremely low, approaching zero. At minimum, adherence to CCR and NEXUS within this patient population would serve to reduce both imaging costs and population radiation dose exposure.

Utility of computed tomographic imaging of the cervical spine in trauma evaluation of ground-level fall.

BACKGROUND: Computed tomography (CT) of the cervical spine (C-spine) is routinely ordered for low-risk mechanisms of injury, including ground-level fall. Two commonly used clinical decision rules (CDRs) to guide C-spine imaging in trauma are the National Emergency X-Radiography Utilization Study (NEXUS) and the Canadian Cervical Spine Rule for Radiography (CCR). METHODS: Retrospective cross-sectional study of 3,753 consecutive adult patients presenting to an urban Level I emergency department who received C-spine CT scans were obtained over a 6-month period. The primary outcome of interest was prevalence of C-spine fracture. Secondary outcomes included fracture stability, appropriateness of imaging by NEXUS and CCR criteria, and estimated radiation dose exposure and costs associated with C-spine imaging studies. RESULTS: Of the 760 patients meeting inclusion criteria, 7 C-spine fractures were identified (0.92% ± 0.68%). All fractures were identified by NEXUS and CCR criteria with 100% sensitivity. Of all these imaging studies performed, only 69% met NEXUS indications for imaging (50% met CCR indications). C-spine CT scans in patients not meeting CDR indications were associated with costs of $15,500 to $22,000 by NEXUS ($14,600-$25,600 by CCR) in this single center during the 6-month study period. CONCLUSION: For ground-level fall, C-spine CT is overused. The consistent application of CDR criteria would reduce annual nationwide imaging costs in the United States by $6.8 to $9.6 million based on NEXUS ($6.4-$15.6 million based on CCR) and would reduce population radiation dose exposure by 0.8 to 1.1 million mGy based on NEXUS (0.7-1.9 million mGy based on CCR) if applied across all Level I trauma centers. Greater use of evidence-based CDRs plays an important role in facilitating emergency department patient management and reducing systemwide radiation dose exposure and imaging expenditures. LEVEL OF EVIDENCE: Diagnostic study, level III.