Accuracy of Plain Radiographs Versus 3D Analysis of Ankle Stress Test

Abstract

Compared to values calculated with the 3D system, radiographic measurements may underestimate the true magnitude of TT and AD changes which could influence clinical decision making.

Biomechanical Analysis of Brostrom Versus Brostrom-Gould Lateral Ankle Instability Repairs

“…16 Thus, the investigators determined that this methodology was preferable to quasi-static loading to failure as this method is an accurate, repeatable, and clinically relevant technique for measuring tibiotalar stability.…”

“…Measurements were recorded in the unloaded state, and then repeated after a 170 N load was applied, to simulate the AD and TT tests used clinically and as previously described by Langer et al ( Figure 1). 16,23,26 The difference in translation between the talus and tibia in the loaded AD test as well as the angle between the tibia and talus in the loaded TT test were calculated. The location of each sensor in 3-dimensional space was tracked using the Optotrak camera system and First Principles software (NDI, Waterloo, Canada) in both the unloaded and loaded conditions, for both the AD and TT test.…”

Operative treatment of lateral ligament instability

“…2). While there should be no hard cutoff, pathologic instability is often diagnosed with greater than 10 degrees of varus tilt or 10 mm of anterior translation or 5 degrees of 5 mm more than the contralateral side [38]. However, asymptomatic ankles may actually have a much narrower range of normal with less than 4 degrees of varus tilt and less than 2 mm anterior drawer seen in a series of normal volunteers [39].…”

“…However, asymptomatic ankles may actually have a much narrower range of normal with less than 4 degrees of varus tilt and less than 2 mm anterior drawer seen in a series of normal volunteers [39]. This is an inexpensive, non-invasive test that can aid in diagnosis, although it may underestimate instability due to patient guarding, the unique morphology of the talus, and difficulty quantifying rotational moments on 2-D radiographs [40,38]. However, stress x-rays are invaluable in helping to determine the degree of instability and differentiating a mechanical instability from a functional one.…”

Epidemiology and Mechanisms of Ankle Pathology in Football

“…Diagnosis of chronic ankle injury is made clinically, based on history and physical exam, and through the use of stress radiographs or other imaging techniques. Although the anterior drawer and talar tilt tests are commonly used clinically to assess ankle instability, their use in radiographic stress imaging may underestimate the true magnitude of talar tilt or anterior displacement [ 99 ]. MRI can confi rm ligament tears and help identify associated injuries that may be overlooked in the physical exam [ 100 ], including cartilage injury, peroneal tendon tear, or fl exor hallucis longus stenosis.…”