From the Guidelines
The appropriate wording for a left angle x-ray to indicate a normal ankle mortise is: "Left ankle radiographs (AP and lateral views) demonstrate a normal ankle mortise with preserved joint space, intact medial and lateral malleoli, and no evidence of fracture or dislocation." This wording is based on the most recent and highest quality study, which emphasizes the importance of standard radiographic protocols, including anteroposterior, lateral, and mortise views, in evaluating ankle trauma 1. When describing a normal ankle mortise, it is essential to mention the following key features:
- Preserved joint space
- Intact medial and lateral malleoli
- No evidence of fracture or dislocation
- Anatomic tibiotalar alignment with symmetric joint space throughout the mortise
- No soft tissue swelling or abnormal calcifications These features are crucial in confirming the normalcy of the ankle mortise, which is the socket formed by the distal tibia, fibula, and talus. Radiologists and orthopedic specialists look for these specific features when evaluating ankle stability and integrity, as emphasized in the study by Smith et al 1. A normal ankle mortise is characterized by parallel joint surfaces, consistent joint spacing, and proper positioning of the talus within the tibial plafond and malleoli, all of which should be mentioned in the report to confirm normalcy. The study also highlights the importance of weight-bearing radiographs, if possible, in providing important information, particularly with fractures of uncertain stability 1. However, in the context of a normal ankle mortise, the focus is on confirming the absence of any abnormalities, rather than assessing stability. Therefore, the recommended wording provides a clear and concise description of a normal ankle mortise, based on the most recent and highest quality evidence.
From the Research
Ankle Mortise Appearance on X-ray
The appearance of the ankle mortise on an x-ray can be described in various ways, depending on the specific findings.
- When the ankle mortise appears normal on an anteroposterior and lateral x-ray, it can be described as follows:
- The mortise view shows a normal medial clear space and a symmetric joint space.
- The lateral view shows a normal talocrural angle and no signs of fracture or dislocation.
- The overall alignment and joint space of the ankle mortise are within normal limits 2.
Radiographic Views for Ankle Fracture Diagnosis
The number of radiographic views necessary for diagnosing ankle fractures has been studied extensively.
- Some studies suggest that two views, such as the anteroposterior and lateral views, may be sufficient for diagnosing ankle fractures in certain cases 3, 2.
- However, other studies recommend using three views, including the mortise view, to ensure accurate diagnosis and detection of subtle mortise malalignment 4, 5.
- The choice of radiographic views may depend on the specific clinical scenario and the suspected type of ankle injury.
Describing a Normal Ankle Mortise
When describing a normal ankle mortise on an x-ray, it is essential to include the following information:
- The mortise view shows a normal joint space and alignment.
- The lateral view shows a normal talocrural angle and no signs of fracture or dislocation.
- The overall appearance of the ankle mortise is symmetric and within normal limits 6.
- Examples of wording for a normal ankle mortise include: "The ankle mortise appears normal, with a symmetric joint space and normal alignment on both the anteroposterior and lateral views" or "The mortise view shows a normal medial clear space, and the lateral view shows a normal talocrural angle, indicating a normal ankle mortise" 4, 5.