The diagnostic accuracy of radiographs in Lisfranc injury and the potential value of a craniocaudal projection.

OBJECTIVE: The purpose of this study is to determine the diagnostic accuracy of radiographs in the diagnosis of Lisfranc injury. In addition, a foot phantom was investigated to determine the optimum degree of craniocaudal angulation on the anteroposterior radiograph to best show the joint. The angle of the joint in patients with midfoot injury was investigated to determine the optimum degree of craniocaudal angulation. MATERIALS AND METHODS: Sixty patients examined by CT had their radiographs evaluated independently and by consensus opinion by two observers, and the diagnostic performance was calculated using CT as the reference standard. A foot phantom was radiographed with varying degrees of craniocaudal angulation, and the radiograph that best revealed the joint was determined. This was compared with the angle of the joint as measured on CT. The angle of the joint in all 60 patients was measured on CT. RESULTS: The radiographs correctly identified 31 of the 45 cases (68.9%) of Lisfranc injury, with a positive predictive value of 84.4%, a negative predictive value of 53.3%, a sensitivity of 84.4%, and a specificity of 53.3%. Twenty degrees of craniocaudal angulation best showed the second tarsal-metatarsal joint of the phantom, and this correlated with a 20° angle measured by CT. The mean (± SD) angle of the joint in the patients was 28.9° ± 5.7°. CONCLUSION: Conventional radiographs miss a significant number of cases of Lisfranc injury. Craniocaudal angulation can better show the joint, and an angle of 28.9° is likely to optimally visualize the joint in the majority of patients.

Spontaneous resolution of post-traumatic calcification.

An 11-year-old girl presented with a swollen medial aspect of the left forefoot following a blunt injury. Initial imaging revealed a well-defined calcific structure with a radiolucent line across it, medial to the head of the first metatarsal. The swelling and pain completely subsided over the course of the following week. Follow-up imaging revealed a near complete resolution of the calcific density. This unusual presentation of acute post-traumatic deposition of calcium hydroxyapatite could be confused with injury to an ossicle.

Wii knee.

We present the case of a 16-year-old boy who injured his knee whilst playing on the video games console Nintendo Wii. The patient presented with an acutely swollen and painful knee to the emergency department of our institution. Initial radiographs revealed an effusion and an osteochondral fracture. Further imaging with magnetic resonance imaging demonstrated evidence of lateral patella dislocation with medial patello-femoral ligamentous damage and a large femoral osteochondral fracture. The patient was successfully treated with surgical fixation of the osteochondral fragment and medial patello-femoral ligament repair. This case highlights the force that can be generated whilst using these new games consoles.

Trauma musculoskeletal ultrasound.

Musculoskeletal ultrasound has benefited from the recent exponential improvement in probe technology to the extent that it is now the imaging modality of choice for many peripheral soft tissue injuries. This article aims to highlight these areas and encourage the use of this modalilty in these scenarios rather than the currently more favoured magnetic resonance imaging scan.