Split Tibialis Anterior Tendon Transfer to The Peroneus Brevis or Tertius for the Treatment of Varus Foot Deformities in Children with Static Encephalopathy: A retrospective case series

Abstract

Introduction: The study purpose was to determine the safety/efficacy of a split anterior tibialis tendon transfer (SPLATT) to the peroneus tertius or brevis in children with static encephalopathy and varus feet.

Methods: A retrospective review of short- and long-term complications, change in ankle range of motion, strength, and gait kinematics. Predictors of postoperative varus or valgus were examined.

Results: One hundred thirty-three patients were included (average age [SD] 10.3 [3.7]), with an average follow-up of 3.9 (3.4) years. Forefoot/hindfoot eversion range of motion improved (P ≤ 0.05), dorsiflexor strength was maintained or improved in 76.9% of patients, and dorsiflexion in swing phase was maintained. Complications occurred in 6 of 133 patients (4.5%) and included 1 transfer failure, 1 wound dehiscence, and four pressure areas from casts. Successful correction was achieved in 77% of patients. Later onset of recurrent varus (14.4%, 10.6% requiring revision surgery) and pes valgus (8.7%, 4.8% requiring revision surgery) occurred. The length of the follow-up predicted the development of the pes valgus (odds ratio 1.28, 95% CI 1.0 to 1.6).

Discussion: SPLATT to the peroneus tertius or brevis is effective, and complications are rare. Subsequent valgus or recurrent varus deformities may occur, possibly requiring repeat surgery.

Figure 1

Photograph showing the incision sites for SPLATT to the peroneus tertius or brevis. (Courtesy of Children's Orthopedic Center, Los Angeles, CA.)

Figure 2

Photograph showing the anterior tibial tendon harvesting and splitting. A, Anterior tibialis tendon identified at the distal, medial incision; (B) Plantar half of the tendon is harvested and a nonabsorbable 2-0 whip stitch is placed through the distal stump; (C) An Ober tendon passer passed through lower leg incision (deep to extensor retinaculum) and the whip stitch retrieved; (D) The tendon splits longitudinally as the suture is retrieved. (Courtesy of Children's Orthopaedic Center, Los Angeles, CA.)

Figure 3

Photograph showing the peroneus tertius identification. A, Peroneus tertius located adjacent to fifth toe extensor (black arrow); (B) Pulling on peroneus tertius everts foot without moving the fifth toe, and the tendon course is seen distally; (C) Vessel loop placed around the tendon. (Courtesy of Children's Orthopaedic Center, Los Angeles, CA.)

Figure 4

Photograph showing the split tendon transfer. A and B, Split anterior tibialis tendon retrieved and passed outside the retinaculum to dorsolateral hindfoot adjacent to the peroneus tertius. (Courtesy of Children's Orthopaedic Center, Los Angeles, CA.)

Figure 5

Photograph showing suturing of the transferred tendon. A, Side-to-side transfer; B, Tendons sutured in a side-to-side fashion with two or three nonabsorbable 2-0 figure 8 sutures while the ankle is held in eversion, with more tension placed on the transferred portion of the tendon than the tension in the medial (native) half of the tendon. (Courtesy of Children's Orthopaedic Center, Los Angeles, CA.)