Flexible flatfoot & HyProCure® arthroereisis.

Flexible flatfoot — pes planovalgus — describes a foot in which the medial arch flattens on standing and the heel rolls outwards, but the joints themselves remain mobile. In children a modest flatfoot is entirely normal up to around age six or seven, and many will develop a healthy arch without any intervention.

A minority, however, do not. When the deformity persists, progresses, or becomes symptomatic, it points to a mechanical fault at the subtalar joint — the joint between the ankle bone (talus) and the heel bone (calcaneus). The talus slides forward and inwards, the calcaneus tips outwards, and the whole foot loses its natural spring. Left unchecked, the same pattern in an adult drives posterior tibial tendon dysfunction and, ultimately, a rigid, arthritic flatfoot.

The good news is that a mobile subtalar joint can be mechanically re-aligned with a small, reversible implant — without cutting or fusing any bone. That procedure is subtalar arthroereisis, most commonly using the HyProCure® stent.

Between the ankle bone and the heel bone there is a naturally occurring space called the sinus tarsi. In a flexible flatfoot that space collapses as the talus slides forward and inwards on the calcaneus. Arthroereisis re-opens that space by placing a small titanium stent inside it — a mechanical “doorstop” that blocks the abnormal collapse while preserving normal joint motion.

The operation is performed as a day-case, typically in around twenty minutes, through a small incision on the outside of the foot. There is no bone cutting and no fusion. Patients are usually up in a protective boot within days, back in normal shoes within weeks, and returning to sport progressively over the following months. Should it ever be required, the stent can be removed.

It is not a procedure for every flatfoot — and that is the point of the consultation. In experienced hands, and with honest case selection, arthroereisis can transform how a symptomatic child or adult walks, plays and works.

Mr Stuart Metcalfe is one of the UK's most experienced consultants in subtalar arthroereisis, with three decades of consultant-level foot and ankle practice across the NHS and private sector. He is the lead author of Subtalar Joint Arthroereisis in the Management of Pediatric Flexible Flatfoot: A Critical Review of the Literature (Metcalfe SA, Bowling FL, Reeves ND — Foot & Ankle International, 2011), the international benchmark literature review of the procedure. He has taught and lectured on paediatric flatfoot and podiatric surgical technique for many years.

A less common credential, but a telling one: Mr Metcalfe elected to have this same procedure performed on his own daughter. Few endorsements of a technique are more honest than choosing it for your own family.

Every arthroereisis at Footconsultant Clinics is planned, performed and followed up by Mr Metcalfe personally — from the first biomechanical assessment through to the return-to-sport review.