Related Experiment Videos
Posterior instability of the talus: an anatomic evaluation
1Department of Orthopaedics and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN 37232.
Foot & Ankle
|August 1, 1989
Summary
This study found that lateral ligaments, not the posterior malleolus, provide posterior talar stability. Therefore, posterior malleolar fractures may not require internal fixation if the fibula remains stable.
Area of Science:
- Orthopedic surgery
- Anatomy
- Biomechanics
Background:
- Posterior malleolar fractures can compromise ankle stability.
- The role of the posterior malleolus and surrounding ligaments in posterior talar stability is not fully understood.
Purpose of the Study:
- To evaluate the contribution of the posterior tibial margin and lateral supporting structures to posterior talar stability.
Main Methods:
- A cadaver study was performed.
- Posterior malleolar fractures (30-50% of articular margin) were created.
- Specimens underwent posterior stressing before and after medial malleolus removal.
Main Results:
- No posterior talar subluxation occurred even with significant posterior malleolar fractures.
- Removal of the medial malleolus did not result in subluxation.
- Lateral supporting structures, including posterior fibulotalar and fibulocalcaneal ligaments, were identified as key stabilizers.
Conclusions:
- Lateral ligaments are crucial for posterior talar stability.
- Posterior malleolar fractures may not necessitate internal fixation if the fibula is anatomically stable.