Syndesmosis Injury and Instability, continued
Measurements are made of the medial clear space (MCS), the tibiofibular clear space (TFCS), the tibiofibular overlap (TFO) and the talocrural angle (TCA). Measurements are taken as shown in diagrams 1 and 2. Normal findings are shown in the table.
Measurement |
AP view |
Mortise view |
Note |
Other methods |
MCS |
< 5 mm |
< 5 mm |
= to superior clear space |
|
TFCS |
< 6 mm |
< 6 mm |
|
|
TFO |
>= 6 mm |
>= 1 mm |
|
|
TCA |
83 +/- 4 |
|
Check talar tilt and compare to other side |
Medial fibular prominence at level of joint |
TFO % |
42% of fibular width |
|
|
|
Note: CT and MRI may help more precisely define the congruency and integrity of the syndesmosis. The measurements shown above are not valid in children.
Stress radiographs are useful in cases where the syndesmosis may appear to be normal on static xrays but is dynamically unstable. Stress xrays may not be tolerated in acute injuries. Intraoperative stress xays are useful to evaluate the syndesmosis during repair of ankle injuries.
this topic [1] [2] [3] |
