Description
Introduction
Addressing forefoot supination leads to improved correction of hindfoot valgus ^1. However, only bony procedures have been established. Sanhudo developed a peroneus-brevis-longus tendon transfer as a potential dynamic alternative ^2. The aim of this study was the pedobarographic analysis of the peroneus-brevis-longus tendon transfer regarding to forefoot varus .
Methods:
25 cadaveric feet (Fresh Frozen Mid Tibia To Tip Toe, Science Care, Phoenix, Arizona, United States) were used. None of the feet showed any relevant deformities or signs of previous surgery. Standing was simulated by using a metal frame which was used in a published protocol ^3. An axial load of 60 kg was applied. The stabilizing tendons were prepared and loaded with traction: Tibialis posterior tendon 40 N, tibialis anterior tendon 40 N, peroneal tendons 44 N, Achilles tendon 300 N. Pedobarography was performed using a pressure measuring film (Pliance®, Novel, Munich, Bavaria, Germany). The measurement was performed natively and after peroneus-brevis-to-longus tendon transfer. The tendon transfers were performed in plantar flexion and eversion based on the described technique of Sanhudo ^2.
Results:
The plantar peak pressure beneath the first metatarsal head increased from 47.86 kPa to 58.20 kPa (p<0.001). The average plantar pressure increased from 23.09 kPa to 27.56 kPa (p<0.001). In contrast, plantar peak - and average pressure beneath the second to fifth metatarsal head, medial and lateral midfoot, heel and entire foot did not change significantly (p>0.05).
Conclusion:
The study presented a reduction in forefoot varus using a peroneus-brevis-to-longus tendon transfer. Cotton osteotomy is currently the gold standard in correction of forefoot varus. Biomechanical studies have shown an isolated increase in the plantar pressure of the first metatarsal head without any influence on the plantar pressure of the fifth metatarsal head after Cotton osteotomy ^4. The same dynamic were shown in this study. Therefore, a dynamic alternative to bony correction through the peroneus-brevis-to-longus tendon transfer appears possible. Further comparative and clinical studies must follow.
