Anatomy And Clinical Application Of Tibial Posterior Tendon

Objective:The posterior tibialis tendon(PTT)is an important stabilizer for the medial longitudinal arch.The posterior tibial tendon dysfunction(PTTD)is the most common cause of adult acquired flatfoot deformity(AAFD).Although it has agreed that the tibialis posterior tendon is high morphological variability,its bands and insertions is not well defined and remains controversial in anatomy discussions.The aim of the work is to systematize the classification of tibialis posterior tendon by anatomical dissection,according to different morphology of bands and insertion.Methods:Our anatomical dissection was performed on 28 lower limbs(8 female,10 male,14 on the left and 14 on the right)fixed in 10% formalin solution.Then,the specimens were photographed,measured,and statistically analyzed.Results: PTT has four bands in addition to the main tendon : anterior band,middle band,posterior band and turn-back band.permanent PTT insertion are the main tendon inserts :the navicular bone,the medial cuneiform bone and the middle band inserts :the intermediate cuneiform bone,the lateral cuneiform bone and the metatarsal bones(the insertion of the metatarsal bone continues to occur,but the number of insertions is different).According to the different bands and the insertions of the PTT,we divide them into four types: I,II,III,and IV.Type I is further divided into four subtypes.I: main tendon and middle band.IA: Insertions are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone.IB:Insertions are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,flexor hallucis brevis.IC:Insertions are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,the cuboid bone.ID: Insertions are the medial cuneiform bone.the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,the cuboid bone,flexor hallucis brevis.II: main tendon,middle band and anterior band.Insertions of type II are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,the cuboid bone,flexor hallucis brevis,fibularis longus tendon.Type III:main tendon,middle band and posterior band,IIIA:Insertions are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,the cuboid bone,flexor hallucis brevis,long plantar ligament(the posterior band ends in the “Y” shape).IIIB:Insertions are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,the cuboid bone,flexor hallucis brevis,long plantar ligament(the posterior band ends in the fan shape).Type IV:main tendon,middle band and turn-back band.Insertions of type IV are the medial cuneiform bone,the intermediate cuneiform bone,the lateral cuneiform bone,the navicular bone,the metatarsal bone,cuboid bone,flexor hallucis brevis,the sustentaculum tali.The different types of PTT were not significantly different between sexes(P = 0.384)and body side(P = 0.731).The different types show differences in Length of the main tendon(P = 0.012)and width of middle band(P = 0.021)of PTT.The single metatarsal insertion of PTT is not different in sexes(P = 0.545)and body sides(P = 0.689).Conclusion:The systematic classification of PTT helps to deepen the understanding of the PTT,and has a positive significance for the treatment of PTTD and biomechanical research related to the PTT.