Idiopathic Tibialis Anterior Tendinopathy Necessitating Tendon Debridement With Adjunctive Autograft Fixation: A Unique Case

Abstract

T ibialis anterior tendinopathy (TAT) is a painful, debilitating injury commonly caused by inflammation of the tibialis anterior (TA) tendon or degeneration of its tendon sheath.1 Tibialis anterior rupture is classically caused by an acute eccentric contraction in the setting of preexisting tendinosis, and patients often recall immediate pain, swelling, loss of function in ankle dorsiflexion causing chronic equinus, and the presence of foot drop or “steppage gait.”1 Others are unaware because of the recruitment of the long toe extensors.1 If a diagnosis of TA tendon rupture is uncertain after history and physical exam, imaging studies such as an magnetic resonance imaging or ultrasound will help confirm. Nonoperative treatment options include ankle foot orthoses and tendo-achilles stretching. However, most patients benefit from surgery to restore active dorsiflexion and physical function. Options for reconstructing the TA tendon include primary repair, tendon transfers, or reconstruction with graft.1 Primary repair can be done with a primary end-to-end repair or a sliding anterior tibial tendon graft (utilized for deficits 2 to 4 cm in length).2,3 Tendon transfers are used when the deficit is larger than 4 cm.1 Techniques utilized include transfer of the extensor hallucis longus (EHL), extensor digitorum longus (EDL), posterior tibial, peroneus brevis, or allograft tendon. EHL tendon transfer is the most common transfer option reported in literature. In cases where tendon transfer is not available or insufficient, a free tendon autograft or allograft can be used. Techniques reported include harvesting the peroneus tertius, semitendinosus, gracilis, plantaris, or Achilles tendon.3,4 TA tendon rupture is an uncommon pathology, and the literature does not provide conclusive evidence for the best operative intervention. Huh and colleagues utilized allograft for an end-to-end interposition of the ruptured TA tendon with distal fixation in the medial cuneiform through a bone tunnel. Our study utilized plantaris autograft as an overlay on an end-to-end TA anastomosis without any additional fixation. Drawbacks associated with the plantaris tendon autograft have historically centered around the need for an extra incision and access to the superficial posterior compartment of the lower leg. The author’s proposed technique involves the convenient utilization of a plantaris tendon autograft for the anterior tibial tendon repair after the recommended gastrocnemius recession. Gastrocnemius recession is recommended to alleviate the associated chronic equinus positioning of the ankle associated with TAT or rupture and allows for easy access to the plantaris tendon. This procedure is hypothesized to have lower complication rates with equal patient outcomes.