Split Tibialis Anterior Tendon Transfer(SPLATT)

The anterior tibialis muscle is located on the anterior-external surface of the tibia. It arises from the external tibial tubercle, the upper two trigeminal processes of the external surface of the tibia and the adjacent medial membranes and takes refuge in the medial sphenoid and the 1st metatarsal. Its contraction causes dorsal extension and pronation of the foot. The anterior tibialis muscle is located in the anterior compartment of the tibia. It is innervated by the deep peroneal nerve and its main antagonist is the long peroneal muscle. The anterior tibialis acts in walking, running, kicking, any activity that requires movement or maintaining the vertical position of the foot.

When the anterior tibialis is overactive or tight (cerebral palsy, muscular dystrophy, spastic tibialis, cerebrovascular accidents, vascular stroke), it tends to pull on the inner part of the foot. The muscles that balance this movement in the outer part of the leg are often weak and cannot maintain the leg in a normal position. This causes the patient to put weight on the outer end of the foot, causing pain and skin ulcers, as well as difficulties in walking and using shoes. The SPLATT procedure balances the traction exerted by the anterior tibialis so that the leg lifts straight up instead of being pulled only on the inner side.

SPLATT surgery is performed under general or regional anesthesia. During the SPLATT operation, the tendon of the anterior tibia is cut longitudinally in two, with each tendon being approximately 10 cm long. One half of the tendon is transferred to the outer part of the foot and fixed to the cuboid or peroneum. The fixation is usually done with an absorbable screw or anchor. Lengthening of the Achilles tendon, lengthening of the posterior tibialis, lengthening of the flexor tendons of the toes or ankle arthrodesis may be required.

Postoperatively, patients should use bacteria, not load the operated foot and have a shin splint for 6 weeks. Anticoagulant injections are needed for 6 weeks to prevent deep vein thrombosis. Suture removal is done 2 weeks after surgery. Complications of surgery include deformity, pain and stiffness, infections, deep vein thrombosis, tarsal tunnel syndrome, nerve injuries and neuropathic pain. Inadvertent elongation of the posterior tibial tendon can lead to excessive deformity correction. The procedure usually has good results, improves foot alignment and improves patients’ ability to use shoes, locomotion and walking without the use of guards and aids.