Adult acquired flatfoot

and tibialis posterior tendonopathy

Surgical options - introduction

The original procedure for tibialis posterior tendonopathy or rupture was debridement and direct repair. This is still standard in feet with tendonopathy but no deformity.

Where the remaining tendon was inadequate, it is usually reinforced by transferring FDL or, more rarely, FHL, into the navicular. An alternative transfer is to split the anterior tibial tendon and transfer part through a tunnel in the medial cuneiform and back through the sheath of tibialis posterior, attaching it proximally (Cobb procedure).

Tendon debridement and transfer alone usually does not restore the arch and was felt not to be durable enough. Medial displacement calcaneal osteotomy (MDCO) is intended to realign the hindfoot biomechanics. The combination of FDL transfer and MDCO is probably most surgeons' main operation for the adult acquired flatfoot that fails non-surgical treatment. Most patients have a tight gastrocnemius +/- soleus which requires lengthening in addition.

Patients with a severe flatfoot have a relatively short lateral foot column (calcaneum/cuboid). The Evans calcaneal lengthening osteotomy and distraction subtalar fusion aim to equalise the medial and lateral columns and hence correct mid/forefoot abduction.

To have a valgus calcaneum with an excessively pronated subtalar joint, and yet have the forefoot flat on the floor, requires that the forefoot be supinated relative to the hindfoot. In most patients this supination is flexible and can be corrected passively along with the hindfoot. In about 20% of patients this supination cannot be corrected passively. Medial column realignment aims to correct this. It is particularly useful when there is deformity through a painful arthritic first tarsometatarsal joint.

Major stiff deformity, sometimes involving the ankle, usually requires corrective fusions.