How Do Different Anterior Tibial Tendon Transfer Techniques Influence Forefoot and Hindfoot Motion?

Abstract

Background Idiopathic clubfoot correction is commonly performed using the Ponseti method and is widely reported to provide reliable results. However, a relapsed deformity may occur and often is treated in children older than 2.5 years with repeat casting, followed by an anterior tibial tendon transfer. Several techniques have been described, including a whole tendon transfer using a two-incision technique or a three-incision technique, and a split transfer, but little is known regarding the biomechanical effects of these transfers on forefoot and hindfoot motion. Questions/purpose We used a cadaveric foot model to test the effects of three tibialis anterior tendon transfer techniques on forefoot positioning and production of hindfoot valgus. MethodsTen fresh-frozen cadaveric lower legs were used. We applied 150 N tension to the anterior tibial tendon, causing the ankle to dorsiflex. Three-dimensional motions of the first metatarsal, calcaneus, and talus relative to the tibia were measured in intact specimens, and then repeated after each of the three surgical techniques. Results Under maximum dorsiflexion, the intact specimens showed 6°(95% CI, 2.2°-9.4°) forefoot supination and less than 3°(95% CI, 0.4°-5.3°) hindfoot valgus motion. All three transfers provided increased forefoot pronation and hindfoot valgus motion compared with intact specimens: the three-incision whole transfer provided 38°( 95% CI, 33°-43°; p \ 0.01) forefoot pronation and 10°( 95% CI, 8.5°-12°; p \ 0.01) hindfoot valgus; the split transfer, 28°(95% CI, 24°-32°; p \ 0.01) pronation, 9°( 95% CI, 7.5°-11°; p \ 0.01) valgus; and the two-incision transfer, 25°(95% CI, 20°-31°; p \ 0.01) pronation, 6°( 95% CI, 4.2°-7.8°; p \ 0.01) valgus.

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

“…Although a whole tendon transfer of the AT is often successful for a correction of forefoot supination associated with idiopathic clubfoot deformity (Knutsen et al, Kuo et al, and Thompson et al), 4 - 6 the whole tendon transfer is generally avoided in the neuromuscular cases because of the concern of achieving balanced coronal plane foot positioning in the short- and long-term in the presence of spasticity and/or dystonia. This can be particularly challenging because tone, strength, and movement disorders often change and evolve over time.…”

Strength of Interference Screw Fixation to Cuboid vs Pulvertaft Weave to Peroneus Brevis for Tibialis Posterior Tendon Transfer for Foot Drop

“…Even with an anticipated loss of 1 grade of strength following anterior transfer of the TP, it is likely that more than 50 N tension would occur at the fixation point. 6,7,17,20 We therefore chose to cyclically load the tendon at 150 N to simulate likely physiological forces encountered during protected partial weightbearing with the ankle immobilized in a boot and also nonweightbearing active ankle dorsiflexion.…”

Club Foot After Treatment;

“…Although Ponseti method is reported to give reliable results, in children older than 2.5 years relapsed deformity may occur. 18 Relapse rate is reported in 54% of patients. 19 Ponseti with 94 club feet with initial success of 80%.…”