J Korean Orthop Assoc.  2002 Dec;37(6):777-780.

Medial Displacement Calcaneal Osteotomy: Biomechanical Effect on Calcaneal Inversion

• Sung IH
• Lee S
• Otis JC
• Deland JT

Abstract

PURPOSE: This study was performed to investigate the dynamic effect of medial displacement calcaneal osteotomy (MCO) on the calcaneal inversion.
MATERIALS AND METHODS
10 fresh-frozen, intact cadaver foot-ankle specimens were tested, using a custom loading apparatus at an orientation consistent with the early heel rise portion (40%) of the gait cycle. Calcaneal inversion was measured with identical ground reac-tion force and tendon force, before and after MCO.
RESULTS
Calcaneal inversion was 2.1+/-2.4degrees in the pre-osteotomy condition and 3.7+/-3.1degrees after MCO. Calcaneal plantar flexion was 7.1+/-0.7degrees in the pre-osteotomy condition and 8.8+/-1.8degrees after MCO. Increases of calcaneal inversion and flexion were significant (intact vs. MCO), (p< 0.05).
CONCLUSION
The inversion capability of the Achilles tendon was enhanced by lengthening its moment arm when its insertion was displaced medially following MCO. MCO, therefore, could compensate for the weaker inverting power of the transferred toe flexor, when treating stage II posterior tibial tendon insufficiency.

Keyword

Calcaneus; Medial displacement calcaneal osteotomy; Inversion

MeSH Terms

Achilles Tendon
Arm
Cadaver
Calcaneus
Gait
Heel
Osteotomy*
Posterior Tibial Tendon Dysfunction
Tendons
Toes