Question 1 · Medium
Untreated pyogenic tenosynovitis of the little finger in a coir worker has spread over a week. Now the palm is swollen, the thumb is held flexed with pain along its sheath, and there is a tender, boggy swelling just above the wrist on the front of the forearm. Through which route did the infection reach the thumb?
- ALumbrical canals to the web spaces
- BUlnar bursa to the radial bursa
- CLymphatics to the epitrochlear nodes
- DMidpalmar space to the thenar space
Show answerHide answer
Answer: B · Ulnar bursa to the radial bursa
The flexor sheath of the little finger is continuous with the ulnar bursa, and that of the thumb with the radial bursa. The two bursae often communicate at the wrist, so infection can pass from the little finger to the thumb as a horseshoe abscess, and both can drain into Parona's space in the distal forearm, which explains the swelling above the wrist. Both sheaths and the forearm space need drainage. Key point: Little finger and thumb sheaths join the ulnar and radial bursae, which connect to form a horseshoe abscess and drain to Parona's space.
- A: Web-space infection spreads through the lumbrical canals but does not reach the thumb sheath.
- C: Lymphatic spread causes lymphangitis and nodes, not sheath infection.
- D: The midpalmar and thenar spaces are deep palmar spaces, not the route between these sheaths.