UK hospital performs first paediatric surface-mounted magnetic femoral lengthening

Alder Hey Children’s Hospital has completed the UK’s initial paediatric procedure using a surface-mounted motorised telescopic nail to lengthen a thigh bone, producing a measurable functional height increase. The case delivered a 3 cm immediate length gain and allowed the nine-year-old patient to resume normal activities within months. The implant is driven non-invasively by a magnetic activator positioned on the skin. The distraction protocol averaged about 1 mm per day and ran for roughly six weeks, guiding bone formation in the gap. Hospitalisation for the implantation was minimal — the child was discharged in under a week — and the internal nail was removed three to four months after insertion. Weekly physiotherapy and clinical reviews accompanied the distraction phase and consolidation. Specialists measured the leg-length discrepancy at 4 cm post-treatment and anticipate about 6 cm total correction by skeletal maturity without repeated external fixation. The team reports the centre has already applied the technique to three additional paediatric patients and other UK units are preparing to adopt it. Compared with external fixators, the internal magnetic approach reduces pin-site complications, lowers pain scores, and improves cosmesis. The method originated from US device developments but required protocol adjustments to protect growing physes in children. Clinicians caution that some patients may need staged procedures on the lower leg later in growth to equalise lengths fully.