Keys To Revising Failed Flatfoot Surgery
Given the lack of consensus on indications and procedures for flatfoot surgery, these authors offer their insights on revisional flatfoot surgery. In addition to discussing diagnostic keys and pearls on appropriate procedure selection, they share their clinical experience in revising both overcorrected and undercorrected flatfoot as well as correcting nonunions.
Researchers originally described flexible flatfoot or adult-acquired flatfoot deformity as a foot that is structurally stable and flattens with weightbearing stress.1 Prior work by Harris and Beath found that a flexible deformity is present 64 percent of the time in the adult flatfoot population.1 In their study, equinus/relative shortening of the Achilles tendon had a role in causing pain and disability in 27 percent of the study population.
Typically, a patient’s foot functions optimally through the gait cycle when the foot maintains appropriate muscle tendon balance coupled with the static structure of the foot. Based on electromyography findings, Basmajian and Stecko originally postulated alterations in the optimal position and function of the posterior tibial tendon as major factors in flatfoot deformity.2
Posterior tibial tendonitis dysfunction (PTTD) is a process that is usually on a continuum. Tenosynovitis progresses to further tendon degeneration, which leads to a change in tendon morphology and subsequently leads to further dysfunction. When the tendon becomes misshapen, the tendon becomes weaker. The midfoot/hindfoot joints collapse and eventually progress to a more rigid, fixed flatfoot deformity with ankle valgus in its most advanced stages. Only approximately 50 percent of individuals report a history of trauma.3 Patients can expect pain, fatigue, joint degeneration and associated deformities such as hallux valgus, hammertoes and metatarsalgia with long-term pathology.4
Currently, there are no universally accepted clinical or radiographic definitions of the average height or the normal range of heights of the longitudinal arch. Recent work by the senior author and colleagues has been able to establish normal radiographic values of the pedal architecture to aid the clinician in successful correction of pes planovalgus deformity.
The goals of conservative management often entail the reduction of clinical symptoms and prevention of flatfoot progression with the use of non-steroidal anti-inflammatory medications (NSAIDs), ankle foot orthoses (AFOs), other devices such as the University of California Berkeley Labs (UCBL) orthosis, and conventional orthotics with associated hindfoot/forefoot accommodation as indicated. One may treat acute tenosynovitis with success utilizing a short walking cast or removable cast boot.5 Historically, gastrocnemius–soleus complex stretching exercises have been helpful with early stage posterior tibial tendonitis and the prevention of precipitating pes planovalgus deformity.6
Currently, there is little agreement on indications for surgery and which procedures surgeons should perform based on clinical findings. There are many classification systems to help guide the clinician with some objectivity. According to Johnson and Strom, in stage 1, the tendon length is normal with mild degeneration present and clinically medial foot pain is present.7 In stage 2, the most common stage, the tendon becomes functionally incompetent and the single heel raise test is positive with a “too many toes sign” visible. In stage 3, a fixed hindfoot deformity develops with possible abutment of the lateral subtalar joint. Finally, Myerson and Bluman popularized stage 4 with valgus tilt of the talus present within the ankle mortise.8
Essential Insights On Diagnostic Imaging