Distal interphalangeal 3 joint ganglion

Clinical information

The patient had a swelling on her dorsal 3rd distal right phalanx since one week. The small but sharp erythematous swelling was slowly getting smaller over the last couple of days. The patient had not much pain (VAS 1) and experienced no functional limitations. She was referred by the general practitioner.

Brief description

The transducer was placed both longitudinal (long-axis) and transverse (short-axis) over the DIP joint of the third phalanx. Left/right comparisons and power Doppler measurements where made. Furthermore, I scanned both statically and dynamically. Dynamic scanning to assess whether the swelling was connected to the tendon, and to assess if it had a connection with the joint. Two transducers where used: a linear 15 Mhz transducer, and a hockeystick 18 Mhz transducer. Images were systematically analyzed by using the SonoSkills pathology checklist.

• SHAPE: a compressible swelling is located superficial to the 3rd extensor digitorum tendon. 
• ECHOGENICITY: The swelling is anechoic, indicating a clear (synovial?) fluid. 
• CONTINUITY: No signs of any (fibre) disruptions of any particular structure can be seen. 
• DOPPLER: power Doppler shows no sign of neovascularization. Some Doppler activity is visible, but this appears to be the result of normal pulsations of the neighboring proper palmar digital artery. 
• FUNCTIONAL: flexion and extension of the DIP joint have been executed ultrasound guided to assess whether the swelling was connected to the tendon, and if it was connected to the joint. There appeared not to be a connection with the tendon. A connection with the joint was only visible while scanning with the hockeystick transducer with the DIP joint in a slight flexion. A thin anechoic line could be seen running from joint to swelling.

Conclusion

Based on the ultrasound findings and SonoSkills pathology checklist analysis I concluded:

• Ganglion (mucous cyst) right dorsal 3rd phalanx (0.64 cm x 0.63 cm) 
• Connected to 3rd DIP joint 
• Not connected to the extensor digitorum tendon 
• No signs of neovascularization