Stephen Ledbetter

Abbreviated MRI for patients presenting to the emergency department with hip pain

OBJECTIVE The objective of our study was to assess the diagnostic performance of two abbreviated hip MRI protocols--coronal STIR images only and coronal STIR with coronal T1-weighted images--as compared with a full hip MRI protocol in patients presenting to the emergency department (ED) with hip pain and negative radiographic findings. MATERIALS AND METHODS The cohort included 385 patients (277 females, 108 males; mean age, 61 years; age range, 16-99 years) who underwent MRI within 1 month of negative radiographs obtained for ED evaluation of hip pain between January 2000 and March 2009. MR examinations were graded independently by two musculoskeletal fellowship-trained emergency radiologists for detection of fracture, avascular necrosis (AVN), and muscle injury in three subsets: coronal STIR images only; coronal STIR images and coronal T1-weighted images; and the full examination. RESULTS MRI detected findings suspicious for fracture in 42% (162/385) of patients, for AVN in 9% (33/385), and for muscle injury in 35% (134/385). The sensitivity and specificity of STIR alone in raising concern for fracture was 99% (220/223) for both readers, with small incremental benefits of adding coronal T1-weighted images. For AVN, specificity was 100% (28/28) with STIR alone, but the addition of coronal T1-weighted images provided substantial benefit by increasing sensitivity from 85% (28/33) to 97% (32/33). For muscle injury, sensitivity and specificity exceeded 95% (128/134) for both abbreviated examinations. CONCLUSION An abbreviated MRI protocol including coronal STIR and coronal T1-weighted images has high sensitivity and specificity for fracture, AVN, and muscle injury in ED patients presenting with hip pain and negative radiographs.

Simplified Diagnostic Algorithm for Lauge-Hansen Classification of Ankle Injuries

Ankle injuries occur in a predictable sequence, allowing a logical understanding of their classification once the injury mechanism is recognized. The Lauge-Hansen classification system was developed on the basis of the mechanism of trauma and is useful for guiding treatment. Three radiographic views of the ankle (anteroposterior, mortise, and lateral) are necessary to classify an injury with the Lauge-Hansen system. Two additional criteria are also necessary: the position of the foot at the time of injury and the direction of the deforming force. Because understanding the mechanism of trauma is fundamental to classifying the injury, three-dimensional movies were assembled for each classification, showing the sequence of ligament rupture and bone fractures that occurs with each type of traumatic mechanism. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115017/-/DC1.

Distal radius fracture

The case shown is that of a closed extraarticular bending fracture of the distal radius (Colles’ fracture), with a few interesting twists. By history, we are told that the patient is a guitarist, which gives him a lower tolerance for loss of range of motion of the wrist. Additionally, on the radiographs we see a comminuted dorsal cortex, a marginal fracture of the sigmoid notch, as well as a volar cortical fragment (Fig. 1 and 2). Although the patient is “neurologically intact” by the history, the displaced volar fragment often becomes a future problem, as it can tether or abrade both the flexor tendons and the median nerve. This volar fragment is described as part of Melone’s type III fracture, in which open reduction or excision of the fragment is recommended (4). Displacement and angulatory corrections can often be achieved by closed reduction and cast immobilization. In this particular case, the patient is starting out shortened, with both dorsal and volar comminution, as well as with the volar spike that normally does not reduce by closed methods. Even if length is achieved with the reduction, immobilization in a cast will not likely preserve it. These factors make successful nonoperative treatment unlikely. Given that operative treatment is the appropriate choice, we are given the option of three possible methods: open reduction and internal fixation (ORIF), bridging external fixation from the radius to the second metacarpal with an external fixator supplemented by K-wires across the fracture site, and the relatively recent development of nonbridging external fixation of the radius alone. The remainder of this discussion will focus on why ORIF with a dorsal or volar buttress plate will give the most predictable result for this patient. First, the volar spike should be reduced by open techniques via a volar incision, no matter which method of fixation is chosen. This will give the best chance at avoiding late complications involving the flexor tendons and/or the median nerve, which may be asymptomatic now, but can become symptomatic when he actually starts using his hand and moving his wrist and fingers. For reduction and fixation of this fracture, we need to translate the distal fragment volarly, reestablish volar tilt and radial height, correct malrotation of the distal radius (this can be seen on the prereduction films by the different appearances of the sigmoid notch on either side of the fracture line), and finally, reestablish a dorsal buttress to maintain the reduction. Whereas all of these goals can be met by any of the proposed fixation methods, they are most directly and most reliably achieved by ORIF using a plate. Given that the patient is a guitarist, achieving and preserving early range of motion of the wrist would be especially to his advantage. Either plate fixation or nonbridging external fixation would allow immediate or near-immediate range of motion of the wrist, whereas a bridging external fixator would keep the wrist immobile for at least six weeks, increasing the difficulty of postinjury rehabilitation. To best preserve painless pronation and supination, an accurate reduction of the fracture with correction of the radial malrotation is important. Although this reduction Journal of Orthopaedic Trauma Vol. 16, No. 8, pp. 608–611