Review Question - QID 3645

The history, physical examination, and images are consistent with a Stage 2B posterior tibial tendon insufficiency. In acquired flat foot deformity, the hindfoot falls into valgus with compensatory varus developing in the forefoot.

Figures A and B show a loss of parallelism between the 1st metatarsal and talus on the lateral view and >30% of talonavicular uncoverage on the AP view. Plantarflexion opening wedge medial cuneiform osteotomy (Cotton osteotomy) is an adjunctive procedure used to correct the residual forefoot varus component, as shown in Figure C, of a flatfoot deformity after the hindfoot has been surgically corrected to neutral. The correction of the residual forefoot varus with the Cotton osteotomy creates a plantigrade foot and restores the tripod effect of the foot.

Hirose and Johnson performed a Level 4 study that showed that a Cotton osteotomy produced good results and may offer advantages over 1st metatarsal-cuneiform fusion including predictable union, preservation of first ray mobility, and the ability to easily vary the amount of correction.

Illustration A is a drawing of the plantarflexion Cotton osteotomy. Illustration B is a drawing of a right-sided foot in neutral position and Illustration C is a drawing of a right-sided foot that shows the presence of forefoot varus after the hindfoot is placed in neutral position. Illustration D is a video that demonstrates a patient with PPTI that has calcaneal eversion and compensatory forefoot varus. Video A demonstrates a surgical technique of how a Cotton osteotomy can be performed.

Incorrect Answers:
1: Dorsiflexion closing wedge medial cuneiform osteotomy would exacerbate the deformity.
2: 1st-3rd tarsometatarsal joint arthrodesis can be performed in lisfranc injuries.
4: Lateral column closing wedge shortening osteotomy is not indicated but an Evans lateral column lengthening osteotomy can be used in posterior tibial tendon insufficiency.
5: Subtalar arthrodesis is indicated in subtalar arthritis