Spaces and Compartments of Hand

Spaces of Hand

Deep space infections occur in one of the three anatomically defined potential spaces within the hand.

1. Thenar, mid-palmar and hypothenar spaces
2. Interdigital subfascial web space
3. Forearm space of parona

Deep hand space	Dorsal border	Volar border	Ulnar border	Radial border	Remarks
Thenar	Adductor pollicis	Palmar aponeurosis	Middle palmar septum	Lateral palmar septum	FPL within synovial sheath, FDP and FDS for index finger, 1st lumbrical, Radial bursa, Palmar digital vessels of thumb and lateral side of index finger – these can be considered as contents or volar border
Mid-palmar	3rd, 4th and 5th metacarpals with fascia covering 3rd and 4th interossei	Palmar aponeurosis	Medial palmar septum	Middle palmar septum	Flexor tendons of 3rd-5th fingers, 2nd-4th lumbricals, Superficial palmar arch, Digital nerves and vessels of medial 3 and 1/2 fingers, Ulnar bursa – these can be considered as contents or volar border
Hypothenar	5th metacarpal	Palmar aponeurosis	Medial palmar septum	Hypothenar muscles
Dorsal subaponeurotic	Extensor tendons and dorsal aponeurosis	Metacarpals and dorsal fascia of interossei
Interdigital subfascial	Dorsal hand fascia and skin	Palmar fascia	Metacarpophalangeal joint and extensor tendon	Metacarpophalangeal joint and extensor tendon
Parona (Forearm space)	Digital flexor tendons	Pronator quadratus	Flexor carpi ulnaris	Flexor pollicis longus	Continuous with midpalmar space

Incisions:

1. Mid-palmar space: Curved incision beginning at the level of distal palmar crease, in line with the long finger and extending ulnar-ward to just inside the hypothenar eminence
2. Thenar space: Curved incision in thumb web parallel to border of the 1st dorsal interossei or along the medial side of thenar crease

Compartments of Hand

Hand comprises of 10 compartments.

Compartment	Muscles	Fasciotomy Incision
Hypothenar	Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi	Ulnar border of hand
Thenar	Abductor pollicis brevis Oponens pollicis Flexor pollicis brevis	Radial margin of thenar eminence
Adductor	Two heads of adductor pollicis	Dorsal over first webspace
Dorsal Interosseous	4 compartments​​	Between 2-3rd & 4-5th metacarpals
Volar Interosseous	3 compartments​	Extended carpal tunnel incision

3 Dorsal fasciotomy incisions:

Incision 1: Longitudinal Incision in 1st Webspace

• First dorsal interosseous muscle (can also release the dorsal fascia of the adductor pollicis)

Incision 2 & 3: Longitudinal Incision in 2nd-3rd, 4-5th Metacarpal space

• Remaining dorsal interosseous muscles (can also decompression volar interosseus muscles)