Compartments of the antebrachial fascia of the forearm: clinically relevant ultrasound, anatomical and histological findings.

PURPOSE: Acute compartment syndrome is defined as a limb-threatening condition caused by bleeding or oedema in a closed muscle compartment surrounded by fascia or bone. It is most commonly encountered in the forearm, which has three compartments: posterior, anterior and lateral. These are surrounded and closed in by the antebrachial fascia, formed by dense connective tissue that facilities their study on ultrasound and is key to fasciotomy treatment. The purpose of this study was to broaden existing ultrasound, anatomical and histological knowledge of the fascia of the forearm to facilitate their identification on ultrasound, with possible clinical and therapeutic applications.
METHODS: The study was performed in 50 cryopreserved upper limbs from adult cadavers from the dissection room of the Faculty of Medicine and Health Sciences. They were examined on ultrasound and subsequent anatomical dissection and microscopy to study the fascia and its relationship with different muscles of the forearm compartments.
RESULTS: Distinct anatomical relationships were observed on ultrasound and dissection between the fascia and the extensor carpi ulnaris, extensor digiti minimi, and anconeus muscle in the posterior compartment, and the flexor carpi radialis and flexor carpi ulnaris in the anterior compartment. They were isolated by the antebrachial fascia and had distinct relationships with the neurovascular structures.
CONCLUSION: These results demonstrate that high-definition ultrasound enables us to locate the antebrachial fascia and particular muscles with a distinct relationship with neurovascular structures. This helps better identify these structures, facilitating diagnosis of any pathology in the area, with potential therapeutic and clinical applications.