Limb lengthening methods, compared.

Three families, one biology

Every limb lengthening method does the same thing to the bone: cut it, wait about a week, then pull the two ends apart at roughly a millimetre a day so new bone forms in the gap. Ilizarov worked that rate out in the 1980s and nothing since has changed it. What the methods change is what does the pulling and what you live with while it happens — and that decides comfort, cost, and which risks you sign up for.

Fully internal nails — PRECICE 2 and PRECICE Max (magnetic), Fitbone, Betzbone and the Guichet nail (mechanical) — sit inside the femur or tibia with nothing showing. There are no pin sites to clean, the scars are small, and most protocols allow earlier partial weight-bearing. The trade-offs are the implant cost, restricted weight-bearing on the titanium nails during lengthening, a second operation to remove the nail, and device-specific failures: premature consolidation, a stalled nail, and — for the recalled Stryde — corrosion at the telescoping junction.

External fixators — the Ilizarov ring frame and the hexapod Taylor Spatial Frame — hold the bone from outside through wires and pins for the whole distraction and consolidation period. They are the cheapest hardware, the most adjustable, and still the tool for deformity correction, infected non-union and bone transport. The price is the frame itself: daily pin-site care, near-universal pin-site irritation, and 20–40 weeks in the device. The largest cosmetic Ilizarov series recorded a complication in 37% of patients.

Hybrids — LON (lengthening over nail) and LATN (lengthening and then nailing) — use a frame to drive the lengthening and an internal nail to hold the result, so the frame comes off in weeks rather than months. LON is the workhorse of high-volume Istanbul practice because it delivers the same gain with a cheaper implant; the cost is a small, real risk of seeding the canal, documented in the one randomised trial.

The pooled evidence does not crown a winner: Marwan 2020’s systematic review of 795 patients found no statistically significant difference in complications per patient between nails, hybrids and frames. What differs is the kindof complication and the surgeon’s volume with the device. Read the method page for the one you are offered, then check how many of that exact procedure the surgeon did last year.