Clinical Indication:
- Treatment of sprain of the tarsometatarsal (TMT) joints.
- Treatment of degenerative arthritis of the midfoot joints.
Features:
- Carbon fiber ankle foot orthosis - controls ankle joint dorsiflexion and load on the Achilles tendon
- Custom functional foot orthosis (one pair) - controls rearfoot pronation, patented “Richie ArchLock™”: offloads the medial-central band of the plantar fascia
- Carbon fiber footplate with toe rocker - offloads dorsiflexion bending moments across the midfoot, 1 cm heel lift bilateral
Mechanism:
The Richie Aerospring LIsfranc Offloading System is designed to improve the protection of the midfoot joints provided by walking boots. While walking boots reduce load on the midfoot from the Achilles and provide a rigid rocker sole, there is no arch contour which is critical to support of the TMT joints. The new Aerospring Lisfranc Offloading System provides a brace to limit Achilles loading, a rigid carbon fiber footplate to reduce bending moment across the midfoot joints and a custom contoured foot orthosis to prevent sagittal plane collapse of the TMT joints. A graduated heel lift system further offloads the Achilles and the midfoot joints
Scientific Background:
Lisfranc sprains or injuries to the TMT joints are often mis-diagnosed, are challenging to treat, and often lead to permanent disability. (1-3) Treatment of the sprain where the midfoot joints are stable, with no evidence of diastasis usually requires immobilization in a walking boot for a minimum of 8 weeks. (3,4) When open reduction and internal fixation is required, the post operative course requires up to 12 weeks of boot immobilization. (4,5)
Walking boots address several deforming forces on the TMT joints but do not provide proper arch support to prevent sagittal plane collapse across the midfoot joints. The bulk and limb length discrepancy imposed by walking boots discourages long tem use and leads to poor patient compliance with poor clinical outcomes. The Richie AeroSpring Lisfranc Offloading System offers a welcome alternative for patients facing long term immobiliazation after a midfoot sprain. The lightweight carbon fiber brace allows ease of ambulation while the thin composite footplate will not disrupt leg length. The brace can be quickly loosened at the proximal attachment to allow full mobility of the ankle while driving an automobile.