Frequency and Characteristics of Extensor Hallucis Capsularis: A Cadaveric Study

Area of Science:

• Anatomy
• Orthopedic Surgery
• Human Anatomy

Background:

• The extensor hallucis capsularis is an accessory tendon occasionally found alongside the extensor hallucis longus tendon.
• Understanding its prevalence and dimensions is crucial for surgical planning, particularly for tendon graft procedures in foot surgery.

Purpose of the Study:

• To determine the frequency, size, origin, and insertion of the extensor hallucis capsularis tendon.
• To provide data that can inform surgical decisions regarding tendon graft utilization.

Main Methods:

• Dissection of 55 adult cadaveric feet (36 male, 19 female; age range 33-90 years).
• Systematic recording of the presence, origin, insertion, length, and width of the extensor hallucis capsularis tendon.
• Intraclass correlation coefficient was used to assess the reliability of tendon measurements.

Main Results:

• The extensor hallucis capsularis tendon was identified in 90.9% of the dissected cadavers.
• The mean length was 11.3 cm (±4.0 cm) and the mean width was 1.6 mm (±0.6 mm).
• Most tendons originated from the extensor hallucis longus and inserted into the first metatarsophalangeal joint capsule.

Conclusions:

• The extensor hallucis capsularis tendon is a frequent anatomical finding, present in most studied cadavers.
• Surgeons should carefully consider the variability in length and narrow width of this tendon when evaluating its suitability as a graft, as these factors may impact its strength.