Improved Gait Capacity after Bilateral Achilles Tendon Lengthening for Irreducible Pes Equinus Due to Hereditary Spastic Paraplegia: a Case Report

OBJECTIVE: Toe walking due to progressive shortening of the calf muscles is common in people with hereditary spastic paraplegia. Achilles tendon lengthening is a treatment option, but clinicians are often hesitant to use this procedure, as it may result in weakening of the calf muscles and, subsequently, in reduced ankle power and knee instability during the stance phase of gait. We report here a case report supporting that these negative side-effects can be avoided in well-selected people with hereditary spastic paraplegia. METHOD: Bilateral Achilles tendon lengthening, combined with bilateral tenotomy of the tibialis posterior and toe flexors, was performed in a 29-year-old woman with uncomplicated hereditary spastic paraplegia who experienced progressive gait instability due to shortening of the soleus and gastrocnemius muscles (resulting in irreducible pes equinus). RESULTS: Bilateral Achilles tendon lengthening resulted in improvement in both subjective and objective outcomes. Self-selected gait speed improved from 0.75 m/s before surgery to 1.07 m/s after surgery (p < 0.001). Knee instability during the stance phase did not occur post-surgery. The ankle moment trajectories normalized after surgery, while peak ankle powers increased. CONCLUSION: Correction of bilateral irreducible pes equinus by Achilles tendon lengthening may improve gait capacity in well-selected subjects with hereditary spastic paraplegia. LAY ABSTRACT Toe walking due to shortening of the calf muscles is common in people with hereditary spastic paraplegia. This case report supports that lengthening of the calf muscles (Achilles tendon lengthening) may improve gait in well-selected people with hereditary spastic paraplegia.