The Fitbone intramedullary limb-lengthening system was developed in partnership with Dr. Rainer Baumgart, a world-famous specialist for intramedullary lengthening with more than 300 operations using this device and the most experienced surgeon in this field.

The product was launched in 1997. Since then, this innovative treatment concept has grown into a global success story with several thousand successful implants. The Fitbone TAA intramedullary lengthening system is intended for limb lengthening of the femur and tibia. With appropriate preoperative planning, it is possible to make axial and torsional corrections as part of limb lengthening.

The Fitbone intramedullary limb-lengthening system is also compatible with the OrthoNext™ digital platform. The OrthoNext software features a reverse planning method module that simulates the target position, osteotomy level and blocking screw placement — enabling a more accurate preoperative assessment, optimized inventory sent to the OR, and, above all, optimized limb correction.

Product Highlights


  • Instruments designed not only for lengthening but for optimal limb alignment
  • Protection of soft-tissues with minimally-invasive instrumentation
  • Safe alignment assessment and blocking screw placement with dummy (trial) nail


  • Reliable power direct to the nail
  • High distraction force independent of nail size
  • No soft-tissue limitations2
  • Power transferred to the nail with small portable Control Set
  • No magnets within the control set3


  • Bone is reamed to exactly fit the implant (step reamer)
  • No over-reaming necessary, therefore, it is a bone-conserving procedure

Manufacturer information is available on the product labels and relevant IFUs.


  • Fitbone® TAA is an intramedullary lengthening system for limb lengthening of the femur and tibia.
  • Fitbone® TAA intramedullary lengthening system is indicated for adult and pediatric (greater than 12 through 21 years of age) patients.


  • Patients with any open wounds or areas with poor soft tissue coverage near the operative site
  • Patients with an anatomic deformity that prevents the device from fitting
  • Patients with poor bone quality that would prevent adequate fixation of the device
  • Patients with compromised capacity for healing
  • Patients with metal allergies and sensitivities
  • Patients in which the implant would cross open epiphyseal growth plates
  • Blood supply limitations, peripheral vascular disease or evidence of inadequate vascularity
  • Insufficient intramedullary space that would lead to cortical weakening or vascular damage during an implantation
  • Patients with a body weight of over 100 kg for TAA11/13
  • Patients with a body weight of over 50 kg for for TAA09
  • Differences in leg length of less than 20 mm
  • No free access for proximal insertion of the intramedullary lengthening nail (e.g., coxa valga)
  • No reliable exclusion of bone infection
  • Expected non-compliance, mentally ill patient or patient with clouded consciousness
  • Pregnancy

In addition to the general risks involved in surgical intervention, the following side effects that might occur despite correctly performed treatment need to be mentioned:

  • Slight tingling sensation up to strong pain in the affected limb, especially during and after distraction
  • Temporary limited mobility of the affected limb