Anatomical study of Lapidus arthrodesis using two different plantar plate systems

Area of Science:

• Orthopedic Surgery
• Foot and Ankle Surgery
• Biomechanics

Background:

• The modified Lapidus procedure is effective for moderate to severe hallux valgus and first ray instability.
• Plantar plate arthrodesis offers superior stability but may cause tendon irritation, necessitating hardware removal.
• Investigating tendon irritation is crucial for optimizing surgical techniques.

Purpose of the Study:

• To evaluate the risk of tendon irritation following plantar first tarsometatarsal joint arthrodesis.
• To identify a "safe zone" for plantar plate placement to minimize soft tissue complications.

Main Methods:

• Plantar plate arthrodesis was performed on 12 cadaveric foot pairs using two different plate systems.
• A meticulous dissection followed plate fixation to assess tendon irritation.
• A "safe zone" for plate placement was determined.

Main Results:

• A safe zone was identified between tibialis anterior and peroneus longus tendon insertions, accessible via a standard medio-plantar approach.
• Both plate systems were fixable within this zone without affecting central tendon portions.
• Peripheral tendon irritation occurred in 42% with one system and 8% with the other; plate bending was often required.

Conclusions:

• The modified Lapidus procedure using plantar plating is a safe technique for the first tarsometatarsal joint.
• A standard medio-plantar approach allows for safe plate placement, avoiding central tendon compromise.
• Careful plate selection and placement are essential to minimize peripheral tendon irritation.