Current Concepts In Surgery For Adult-Acquired Flatfoot
Although an abundance of research into the treatment of adult-acquired flatfoot (AAF) has led to improved standardization of surgical options, discrepancies still exist in how surgeons approach stage II flatfoot. These authors offer insights into surgical management of stage II AAF with a special emphasis on medial transpositional osteotomy of the posterior calcaneus and lateral column lengthening.
Adult-acquired flatfoot (AAF) is a common musculoskeletal condition that we encounter in day-to-day practice. There have been more articles published relating to AAF in peer-reviewed journals in the past 10 years than on virtually any other topic.
Accordingly, once nebulous treatment options have become more formalized, especially with surgery. The surgical management of AAF has been enhanced by improved classification systems and advances in technology. However, in spite of this, differences exist among surgeons managing stage II AAF. These differences in surgical approaches appear to be based on geographic location, residency training, etc.
Improved classification systems are a major reason for better procedure selection in managing stage II AAF. The original classification system proposed by Johnson and Strom in 1989 described three stages of AAF that we have used to guide us in choosing procedures.1 Myerson modified this classification system to include stage IV patients who present with ankle valgus in addition to a fixed flatfoot deformity.2 Stages I, III and IV are straightforward and clearly delineate pathology at each specific stage. However, this is not the case with stage II adult-acquired flatfoot. Stage II AAF is a continuum in which surgical therapy depends on when one encounters a patient in this temporal process.
The clinical practice guidelines published by the American College of Foot and Ankle Surgeons in 2005 divided stage II AAF into early (II-A) and late (II-b) stages to clarify the specific findings associated with various stages.3 A recent classification published by Haddad and colleagues has divided stage II flatfoot into five different subcategories (A-E):4
A. hindfoot valgus;
B. flexible forefoot supinatus;
C. fixed forefoot supinatus;
D. forefoot abduction; and
E. medial ray instability.
Our surgical approach to stage II AAF is based on this contemporary classification system, which appears more practical when choosing surgical procedures to address adult-acquired flatfoot.
A Closer Look At The Management Of Stage II AAF
Virtually all patients with stage II AAF have some degree of equinus that requires posterior muscle group lengthening, which will restore calcaneal inclination and maintain a plantigrade foot following osseous realignment. We typically perform a gastrocnemius recession, which seems sufficient in most cases of stage II AAF. There are times when gastrocnemius recession may not provide an adequate amount of dorsiflexion following realignment of a rather severe deformity. However, this is rare in stage II AAF. Rather, we have found an Achilles tendon lengthening to be necessary in some cases of stage III and IV AAF when the magnitude of deformity is large.