Anatomical Classification for Plantaris Tendon Insertion and Its Clinical Implications: A Cadaveric Study

Area of Science:

• Anatomy
• Orthopedics
• Kinesiology

Background:

• The plantaris tendon (PT) is a small, often overlooked, muscle in the leg.
• Its insertion point relative to the calcaneal tendon (CT) may have biomechanical implications.
• Understanding PT insertion morphology is crucial for diagnosing and treating lower limb pathologies.

Purpose of the Study:

• To investigate the morphological characteristics of the plantaris tendon (PT) insertion.
• To classify PT insertion types in relation to the calcaneal tendon (CT).
• To explore potential links between PT morphology and calcaneal tendon (CT) tendinopathy.

Main Methods:

• Dissection of 108 adult formalin-fixed Korean cadaver feet.
• Evaluation of morphological characteristics and measurements of the PT insertion.
• Classification of PT insertion into distinct types based on location and relation to the CT.

Main Results:

• Five distinct types of PT insertion were identified.
• Type 1 was the most common (63.1%), followed by Type 5 (23.1%).
• The plantaris tendon (PT) exhibited a changing morphology from proximal to distal, and absence of the PT was noted in 6.5% of cases.

Conclusions:

• This study established a classification system for plantaris tendon (PT) insertion morphology.
• The identified variations in PT insertion may predispose individuals to calcaneal tendon (CT) tendinopathy.
• Further research into the biomechanical impact of PT insertion variations is warranted.