Ulnar Slip Flexor Digitorum Superficialis Excision in Trigger Finger Surgery: Anatomic Study.

Area of Science:

• Hand surgery
• Orthopedic surgery
• Anatomy

Background:

• Surgical treatment for trigger finger sometimes requires flexor digitorum superficialis (FDS) tendon resection.
• Ulnar FDS slip excision via a palm-only approach is described, but its anatomical outcomes are not fully understood.
• Quantifying residual tendon length is crucial for understanding potential persistent triggering.

Purpose of the Study:

• To quantify the residual distal FDS tendon stump length after ulnar slip excision in the palm.
• To determine the relationship between the residual stump and the distal edge of the A2 pulley.

Main Methods:

• Ulnar FDS slip excision was performed in 19 cadaveric digits through a palm-only incision.
• Measurements of the residual distal tendon stump length were taken.
• The distance from the cut end of the slip to the distal edge of the A2 pulley was recorded.

Main Results:

• A mean residual stump length of 26.2 mm was observed within the sheath.
• The average distance from the cut end to the A2 pulley's distal edge was 4.9 mm.
• Camper's chiasm remained intact in all specimens, and the excised segment was shorter than the remaining distal tendon.

Conclusions:

• Isolated palm-only FDS tendon slip excision leaves a substantial residual stump.
• The residual stump's proximity to the A2 pulley varies, and Camper's chiasm is preserved.
• Intraoperative assessment can guide decisions on complete FDS slip excision to address residual triggering.