Surgeons explain the benefits of the FITBONE® method

Around the world, WITTENSTEIN intens works exclusively with selected Centers of Excellence. Here, patients receive treatment with FITBONE® from experienced, trained surgeons. Learn the benefits of FITBONE® over other treatment methods directly from international specialists.


WITTENSTEIN intens GmbH - Walter-Wittenstein-Straße 1

The benefits of FITBONE®

Around the world, WITTENSTEIN intens works exclusively with selected Centers of Excellence. Here, patients receive treatment with FITBONE® from experienced, trained surgeons. Learn the benefits of FITBONE® over other treatment methods directly from international specialists.

The FITBONE® System consists of the following components

The FITBONE® System is used for correcting leg length discrepancies. With appropriate preoperative planning, it is possible to make axial and torsional corrections as part of limb lengthening.

The FITBONE® intramedullary lengthening nail can

be used to achieve an extension of 60 mm in the

lower leg (tibia) and 80 mm in the upper leg (femur).

The energy required for the distraction process

is transferred to the receiver implanted beneath

the skin by applying an external controller set.

After the bone has been severed, it is stabilized

by means of the intramedullary lengthening nail.

After a period of rest, the patient can resume treatment

independently at home.

FITBONE® is surgically implanted into the bone.

There is no contact between the implanted intramedullary

lengthening nail and the outer surface of the patient's body.



The external Control Set consists of control electronics and a transmitter. The transmitter is placed on the receiver implanted beneath the skin to send the power required for the distraction process.

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All surgeons participate in an intensive training program in our Center of Excellence. We also assist them with the precise planning of the first operation.

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We offer complete starter sets for all standard FITBONE® designs, which can also be used to remove the implant later.

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A leader in quality, reliability and experience

Simple process

Each lengthening action takes around 90 seconds. The patient performs it independently at home about three times a day. The distraction rate is determined by the surgeon and is one millimeter per day, so 80 millimeters of lengthening takes approximately 80 days. After the distraction phase comes the consolidation phase, during which the reformed bone hardens.

The operated limb can bear partial weight relatively early on. Near the end of the distraction phase, this process can be gradually increased to full weight-bearing. This allows patients to return to their personal and professional routines earlier.

After complete consolidation of the bone, i.e. after one to one and a half years after implantation, the FITBONE® intramedullary lengthening nail and the receiver must be explanted.

An expert's opinion

"There are many possible benefits: less scarring, improved esthetics, better body image and psychological well-being, no irritation from pins or wires, less pain, no unusual infections, prevention of secondary axial deviation, less stiffness in the joints, higher level of activity during the consolidation process, faster rehabilitation, reduced risk of neurovascular impairment from insertion of wires or screws, and improved ability to work during and after treatment."

Hasler CC, Krieg AH, Current concepts of leg lengthening. J Child Orthop. 2012; 6:89-104

The FITBONE® for special needs

Custom-made devices are manufactured according to the specific needs of our patient. One example is a lengthening nail that uses segment transport to produce new bone following a bone resection (as a result of an accident or a tumor). Healthy bone tissue is transferred over the defective area and forms new bone.

Our 'Centers of Excellence' concept guarantees the highest quality and safety

Only qualified orthopedic clinics are approved as Centers of Excellence for FITBONE® treatment. Preconditions include demonstrated experience and the willingness to play a leading role in limb lengthening and deformity correction. Training involves an intensive training program and learning the Reverse Planning Method developed by Prof. Rainer Baumgart. We also offer participation in FITBONE® User Meetings and the sharing of experiences in our Center of Excellence network.

Further publications

  • Krieg, A. H.; Beinlängendifferenzen bei Kindern und Jugendlichen – Diagnostik und Therapieoptionen. PAEDIATRICA Vol. 28 Nr. 1 2017
  • Lenze, U., Krieg, A. H.; Intramedullary lengthening nails: can we also correct deformities? J Child Orthop 15. November 2016
  • Paulsen, J. F., Warburg, F .E., Christensen, K.S. & Holmgaard, R.; Høj femuramputation behandlet med fri lap og forlængelsessøm muliggjorde protesebrug [A free musculocutaneous flap and an intramedullary nail made the use of a prosthesis possible in a high traumatic femoral amputation]. Ugeskr Læger 2016;178
  • Accadbled, F. et al.; Bone lengthening using the FITBONE® motorized intramedullary nail: The first experience in France. Orthop Traumatol Surg Res. 2016 Feb
  • Dahl, M. T.; Motorized, Telescopic, Intramedullary Lengthening Nails for Limb Length and Deformity Correction. Techniques in Orthopaedics® Volume 30, Number 3, 2015
  • Black, S. R. et al.; Lengthening in Congenital Femoral Deficiency - A Comparison of Circular External Fixation and a Motorized Intramedullary Nail. THE JOURNAL OF BONE AND JOINT SURGERY 2015; 97:1432-40
  • Baumgart, R. et al.; Limb Lengthening: Computerized, in: Rommens P M, Hessmann M H (Hrsg.) Intramedullary Nailing: A Comprehensive Guide 2015; 29:505-525
  • Horn, J. et al.; Femoral lengthening with a motorized intramedullary nail. Acta Orthopaedica. 2015 Apr;86(2):248-56
  • Kold, S. et al.; Bone transport of the tibia with a motorized intramedullary lengthening nail — a case report. Acta Orthopaedica 2014; 85 (2)
  • Kücükkaya, M. et al.; Femoral lengthening and deformity correction using the Fitbone motorized lengthening nail. J Orthop Sci. 2014
  • Handlbauer, A., Ganger, R.; Ergebnisse nach Beinverlängerung und Achskorrektur mit einem vollimplantierbaren, motorisierten, intramedullären Verlängerungsmarknagel. Jatros Orthop & Rheumatol. 5/13:118
  • Baumgart, R., Baumgart, T.; Der vollautomatische, motorisierte Segmenttransport. Trauma Berufskrankh 2012 14: 90-98
  • AL-Sayyad, M. J.; Lower limb lengthening and deformity correction using the Fitbone motorized nail system in the adolescent patient. J Ped Orthop. B 2012;21:131–136
  • Dincyurek, H. et al.; Functional results of lower extremity lengthening by motorized intramedullary nails. Acta Orthop Traumatol Turc. 2012; 46(1):42-49
  • Hasler, C. C., Krieg A. H.; Current concepts of leg lengthening. J Child Orthop. 2012;6:89-104
  • Lenze, U. et al.; Ausgleich posttraumatischer Beinverkürzungen mit einem motorisierten intramedullären Nagel. Unfallchirurg. 2011;114:604-610
  • Krieg, A. H. et al. Intramedullary leg lengthening with a motorized nail. Acta Orthopaedica. 2011;82(3):344–350
  • Krieg, A. H. et al.; Ilizarov hip reconstruction without external fixation: a new technique. J Child Orthop. 2010;259-266
  • Baumgart, R.; The Reverse Planning Method for Lengthening of the Lower Limb Using a Straight Intramedullary Nail with or without Deformity Correction. Operative Orthopädie und Traumatologie 2009;21:221-33
  • Baumgart, R. et al.; A Fully Implantable, Programmable Distraction Nail (Fitbone) – New Perspectives for Corrective and Reconstructive Limb Surgery. New Developments in Techniques and Applications Chapter 4.11. 2006
  • Baumgart, R. et al; Der zentrale Segmenttransport optimiert die knöcherne Defektrekonstruktion. Unfallchirurg 2005 108:1011–1021

Locations of FITBONE® centers

FITBONE® center in Germany


ZEM Germany – Zentrum für korrigierende und rekonstruktive Extremitätenchirurgie München

Nymphenburgerstr. 1

80335 Munich


+49 89 5434896-0

+49 89 5434896-19

Contact person

Prof. Dr. Dr. med. Rainer Baumgart