MUTARS® Xpand® (growing prosthesis)

MUTARS® Xpand® is a growing prosthesis developed by Implantcast together with its partner Wittenstein Intense, for pediatric patients in whom tumor resection requires reconstruction of a bone segment that is still growing.

The growing modules of MUTARS® Xpand® use a miniaturized mechatronic actuator inside the prosthesis, activated by coupling energy from outside the skin. Lengthening is thus performed non-invasively, without additional surgery — reducing the risk of infection (5 cm lengthening → 170 mm reconstruction length; 7.5 cm → 195 mm; 10 cm → 220 mm). Once lengthening is complete, the Xpand components are replaced with standard MUTARS® components.

There is also the "biological" variant MUTARS® BioXpand, in which an interim prosthesis is later replaced with a motorized lengthening nail (FITBONE®), using the principle of callus distraction to regenerate the patient’s own bone. All Xpand and BioXpand components are custom-made implants, planned and manufactured for each patient based on a scaled radiograph. By 2017, 650 Xpand and BioXpand prostheses had been successfully implanted.

• Reconstruction after tumor resection in pediatric patients with growth potential.
• Compensation for limb length discrepancy through non-invasive lengthening.
• BioXpand variant: regeneration of the patient’s own bone through callus distraction (with a FITBONE® nail).