Parona Space

spatium Paronae

Parona space is the potential space in the distal anterior forearm between the flexor digitorum profundus tendons anteriorly and the pronator quadratus posteriorly. It is bounded proximally by the FDP muscle bellies and distally by the carpal tunnel entrance. It communicates with the radial and ulnar bursae in the hand, and its infection is typically a component of the horseshoe abscess that involves both bursae via this space.

Region: Forearm

Clinical Relevance

Clinical Notes

Parona space infection produces a swelling in the distal forearm volar surface with the wrist held in flexion to relieve tension, pain on passive finger extension, and tenderness over the distal forearm. Horseshoe abscess is a classic presentation where thumb flexor sheath infection tracks proximally through Parona space to communicate with the ulnar bursa, producing a U-shaped infection involving both radial and ulnar bursae simultaneously. Surgical drainage of horseshoe abscess requires three incisions: thumb, little finger, and Parona space.

Pathology

Common Injuries & Conditions

Horseshoe Abscess Involving Parona Space

Thumb flexor sheath infection tracking proximally through Parona space and communicating with the ulnar bursa produces a horseshoe abscess involving three spaces simultaneously; emergency drainage through proximal (Parona space), radial (thumb), and ulnar (little finger) incisions with irrigation prevents flexor tendon necrosis.