The Fitbone™ intramedullary limb-lengthening system was developed in partnership with Prof. Rainer Baumgart, a world-famous specialist for intramedullary lengthening with more than 2000 Fitbone™ limb lengthening's.
Since its launch in 1997, this innovative treatment concept has grown into a global success story. The Fitbone TAA intramedullary lengthening system is intended for limb lengthening of the femur and tibia. With the combination of preoperative planning, specialist Fitbone™ instrumentation and the Fitbone™ lengthening nail, it is possible to make axial and torsional corrections as part of limb lengthening.
The Fitbone intramedullary limb-lengthening system has been incorporated into the OrthoNext™ digital platform. The OrthoNext software features the 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.

Benefits to Surgeon


  • 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 limitations
  • Power transferred to the nail with small portable Control Set
  • No magnets within the control set


  • 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