Lateral malleolar crest and its clinical importance.

PURPOSE: During study of anatomy of a fractured posterior malleolus of the ankle on CT scans, the authors noticed a prominent crest on the lateral malleolus, which they termed the lateral malleolar crest (LMC). As, in their view, LMC is a clinically important structure which was only briefly mentioned by a few authors without an official term, they focused on the anatomy of this structure. MATERIALS AND METHODS: A total of 352 dry fibulae were analyzed and the following parameters recorded: (F) length of the fibula, (LMC) total length of LMC, (A) length of the part of the examined crest from the superior border of the articular facet of the lateral malleolus (AFLM) to its most proximal intersection with the midline of the fibula, (B) height of the medial triangular rough surface, and (A/F) A/F ratio. RESULTS: The crest was observed in all specimens. (F) was 346.5 ± 26 mm (95% confidence interval [CI] 344-349), (LMC) was 85.4 ± 11.6 mm (95% CI 84.2-86.6), (A/F) was 25% ± 3% (95% CI 24.7-25.3) in the whole group. (A) was 25.9 ± 6.5 mm (95% CI 24.8-26.8) in the whole group, (B) was 34.9 ± 4.7 mm (95% CI 34.3-35.5) in the whole group, 36 ± 6.1 mm (95% CI 35.1-36.9). CONCLUSION: LMC is an important structure on the lateral malleolus. The knowledge of its anatomy is essential for placement of syndesmotic screws or/and the fibular plate.

"Double Maisonneuve fracture": an unknown fracture pattern.

PURPOSE: The aim of this study was to describe pathoanatomy and to raise awareness of a fracture of the lateral malleolus combined with a high subcapital fracture of the fibula caused by a dislocation mechanism. METHODS: The study comprised 11 patients, 5 men and 6 women, with the mean age of 57 years (range, 21-87), with a "Double Maisonneuve fracture". Individual lesions of ankle structures were described on the basis of radiographs, CT, and intraoperative findings. RESULTS: The distal fibular fracture was classified as Weber type B in 1 case and Weber type C in 10 cases. The proximal fibular fracture was described as a subcapital oblique spiral fracture with metadiaphyseal involvement in nine cases and a high short oblique fracture with fibular head involvement in two cases. Injury to the deltoid ligament was revealed in six cases; a bicollicular fracture of the medial malleolus was found in five patients. Posterior malleolar fractures were classified as type 1 in eight cases and type 2 in three cases. Avulsion of the Chaput tubercle was detected in four cases. Injury to the interosseous tibiofibular ligament was assessed in nine patients. CONCLUSION: Double Maisonneuve fracture is a rare but probably underreported injury that must be taken into consideration during examination, as it may be easily overlooked. The essential part of diagnosis is a careful clinical examination and radiological assessment of the lower leg with additional CT examination of the ankle.

Pathoanatomy of Maisonneuve fracture based on radiologic and CT examination.

INTRODUCTION: Although Maisonneuve fracture (MF) is a well-known type of ankle fracture-dislocation, there is still a lack of information about the epidemiology and the extent of all associated injuries. The aim of study is to describe MF pathoanatomy on the basis of radiographs, CT scans and intraoperative findings. MATERIALS AND METHODS: The study comprised 54 adult patients. MF was defined as an ankle fracture-dislocation with a fracture of the fibula in its proximal quarter. Ankle radiographs and lower leg radiographs were obtained in all patients. Computed tomography (CT) examination was performed in 43 patients, of these in 34 patients in combination with 3D CT reconstructions. A total of 51 patients were treated operatively, and in 38 of these an open procedure was performed. RESULTS: The fibular fracture-fibular head was involved in four cases, and the subcapital region of the proximal quarter of the fibula was affected in 50 cases. Fractures of the posterior malleolus were identified in 43 of 54 patients (80%). Injury to the deltoid ligament was recorded in 27 cases (50%), a fracture of the medial malleolus in 20 cases (37%) and medial structures were intact in 7 cases (13%). Position fibula in fibular notch-in 9 cases the position changed only minimally, in 11 cases the space between the tibia and the fibula was larger than 2 mm, in 20 cases widening of the tibiofibular space was associated with external rotation of the fibula, in 2 cases fibula was trapped behind the posterior tibial tubercle and in 1 case it was associated with a complete tibiofibular diastasis. CONCLUSION: MF is a variable injury, always associated with rupture of the anterior and interosseous tibiofibular ligaments. CT examination should be employed widely in MF, and MRI should be considered under special circumstances.