The second dorsal interossei inserts onto the radial aspect of the middle finger, the third on the ulnar aspect of the middle finger, and the fourth on the ulnar aspect of the ring finger.

They insert into proximal phalanx and dorsal apparatus. The second, third, and fourth dorsal interossei originate from their adjacent metacarpals and pass volar to the deep transverse metacarpal. The radial artery and vena comitans pass through a gap between the two origins of this muscle. These tendons have a primarily bony insertion onto the base of the second proximal phalanx. The radial head of the first dorsal interossei arises from the ulnar aspect of the first metacarpal, while the ulnar head arises from the radial aspect of the second metacarpal. The three volar interossei are bipennate muscles that arise from the second, fourth, and fifth metacarpal, pass volar to the deep transverse metacarpal ligament, and insert onto the dorsal apparatus. 7Both muscle groups are metacarpophalangeal joint flexors and proximal interphalangeal joint extenders. The dorsal interossei are finger abductors away from the axis of the third ray, while the volar interossei adduct the fingers. The median nerve has been transected proximal to the carpal tunnel, and the palmar cutaneous branch of the median nerve was removed with subcutaneous tissues.

The hypothenar compartment (A), carpal tunnel (B ), and thenar compartment (C) are visualized. 32.2 Volar view of the hand with skin, subcutaneous tissues, palmar aponeurosis, and flexor tendons removed. From left the right, the first through fourth dorsal interossei (*), and the abductor digiti minimi (A) are visualized. 32.1 Dorsal view of the hand with skin and subcutaneous tissues and finger extensors removed. It should be noted that some surgeons refer to each volar and dorsal interosseous muscle as a separate space. 32.2): the thenar, hypothenar, adductor, interosseous, carpal tunnel, and digit. Typically, the hand has been divided into six spaces (▶ Fig. Hand compartments are enclosed spaces by connective tissue or bone. As Ortiz and Berger pointed out, fasciotomy wounds may present a cosmetic challenge, but this is far outweighed by the potential dysfunction of an undiagnosed hand compartment syndrome. 5Until further research is available, we recommend aggressive treatment with surgical decompression when clinical suspicion is high. 4While anatomical studies are controversial, clinical studies documenting the results of neglected compartment syndrome support prompt and aggressive treatment. 3It should be noted that some research supports little to no tough fascial tissue surrounding these compartments. Studies have supported the presence of distinct myofascial compartments of the hand, and much of the contemporary teaching for treating compartment syndrome is founded on this.

2Understanding the anatomy and variability of the hand compartments is required for prompt and effective treatment of this potentially devastating problem. Litigation often stems from missed compartment syndrome with an average malpractice award of 280,000. Failure to diagnose compartment syndrome of the hand can lead to intrinsic muscle necrosis, followed by fibrosis and loss of function. 1Surgeons must have a high level of clinical suspicion even after seemingly innocuous injuries such as injection injury or careless intraoperative positioning. The causes of compartment syndrome of hand are numerous, ranging from restrictive dressings to industrial accidents. A thorough knowledge of the discrete myofascial compartments of the hand is critical when a surgeon is confronted with a severely injured hand with possible compartment syndrome.