The leg interosseous membrane maintains the tibia-fibula separation and transmits forces between the two bones. Its distal thickening contributes to the syndesmosis complex. In leg compartment syndrome, fasciotomy requires decompressing all four compartments — the anterior and posterior compartments are separated by the IOM, and the IOM may need to be incised at the interosseous border to fully decompress the deep posterior compartment.
| Origin | Interosseous border of the tibia |
|---|---|
| Insertion | Interosseous border of the fibula — the dense fibrous membrane between the two leg bones |
| Actions | Maintains the tibiofibular relationship; transmits forces between the tibia and fibula; provides attachment for anterior and posterior compartment muscles |
|---|
In four-compartment fasciotomy for acute leg compartment syndrome, the interosseous membrane between the anterior and posterior compartments (at the fibular interosseous border) must be released to ensure complete deep posterior compartment decompression. Incomplete fasciotomy leaving the deep posterior compartment compressed produces persistent compartment syndrome.
IOM release required during four-compartment fasciotomy to decompress the deep posterior compartment of the leg.
