FAQ

A personal presentation in our consultation is always recommended, because only then an exact picture of your situation can be obtained.

You can make an appointment via the contact form or by phone at 089 54348960. Our office hours are always on Mondays and Fridays.

Please bring your insurance card and all previous findings, including X-rays. No X-ray images need to be taken separately.

The first observations that a bone can grow under tension date back more than 150 years. The method has been used clinically for about 50 years.

The bone is gently cut and then slowly pulled apart at about 1 mm / day. New bone forms in the gap, which subsequently shapes and strengthens to be no different from naturally grown bone.

In theory, there are no limits to how much the bone or the surrounding soft tissue can be lengthened. Lengthening of the femur (thigh bone) and tibia (shin bone) by 10 cm or more each is feasible in theory. However, if the lengthening of a bone is excessive relative to the surrounding soft tissue, tightening of the less stretchable structures such as ligaments and tendons can lead to displacement and stiffening of the adjacent joints.

Blood formation takes place mainly in the flat bones (ribs, vertebrae, pelvis), and not in the long bones of the legs and arms. Therefore, no adverse effects are to be expected from intramedullary nails being placed in the long bones, even if an intramedullary nail is inserted in all bones of the extremities.

The computer-controlled FITBONE distraction nail has a powerful and reliable electric motor with the widest range of applications. The Precice distraction nail has a simple design and is driven by rotating magnets.

Ring fixators (also called Ilizarov apparatuses) have been largely replaced in the past 10 years by so-called hexapods, whose settings are calculated by computer programs. Alternatively, there are also light metal fixators attached to one side of the bone, which are relatively more comfortable for the patient, particularly in the thigh.

Bone lengthening and related bone distraction treatments are relatively uncommon. Only a center with expertise in these types of deformity has the necessary logistics to perform treatment safely. The surgeon must have a great deal of experience while still being personally accessible to the patient during and after surgical treatment.

All implants are available at ZEM-Germany. However, the FITBONE intramedullary distraction nail preferred because of its superior performance.

Whenever medically possible, an intramedullary distraction nail is recommended at ZEM-Germany, as these implants offer optimum treatment safety and comfort. However, ZEM-Germany also has particularly light and technically advanced external fixators in cases where the use of an intramedullary distraction nail is not possible.

All major operations are performed in one of our partner hospitals, where we have access to excellently equipped operating theaters with certified hygiene standards, very dedicated nursing care and, if required, an observation unit for the first night after surgery.

On average, about 200 corrective surgeries are performed at ZEM-Germany every year. Distraction nails are used in about 100 of these per year — almost 2,000 times since ZEM-Germany was founded.

In cases where there is a medical indication for surgical lengthening, treatment costs are covered by both public and private health insurance funds. Non-medically indicated operations must be paid for by patients themselves. An intramedullary distraction nail costs about €15,000. Surgical treatment and aftercare during lengthening of a bone costs about €35,000. An exact calculation is made after the initial consultation at ZEM-Germany.

Patients with public insurance are requested to present their insurance card. Privately insured patients or publicly-insured patients with private supplementary insurance should provide corresponding proof. Self-pay patients need their identity card and can pay in cash or by credit card. If X-rays have already been taken, these should be brought by the patient as well, on CD-ROM if possible, to avoid repeating x-ray examinations.

Travel costs to or from inpatient treatment in the clinic are usually covered by health insurance companies. Typically, insurance companies will not reimburse for travel costs to outpatient consultations, but it is advisable to request reimbursement in any case, since ZEM-Germany, with the special treatment options offered here, is usually the closest "suitable" treatment option.

Leg length differences can also be corrected by shortening the longer leg. In particularly tall people, shortening both legs is a cosmetic measure that patients must pay for themselves.

On the thigh can be shortened 3-4 cm and on the lower leg 2-3 cm without adverse consequences. Beyond that, it should be done in two steps.

If there is a leg length difference, the health insurance will pay for the treatment. A cosmetic leg shortening to reduce the body size costs between 20.000€ and 50.000€ depending on the extent and is not covered by the health insurance.

Through a small skin incision, a segment is removed from the middle of the bone shaft and the remaining bone ends are pushed together. Stabilization is provided by an intramedullary nail, which is removed after the bone has healed.

The stay in the clinic lasts about 3-4 days. This is followed by partial weight bearing and the use of crutches for 6-12 weeks. After that, full weight bearing can be resumed.

In the case of leg length discrepancies, the leg that also has a malposition should always be treated so that both can be corrected during surgery. In many cases, however, this question does not arise depending on the patient's height.

If the leg is disproportionately shortened, blood vessels may kink, resulting in vascular occlusion.

Arm lengthening procedures are performed almost exclusively on the upper arm. Here, too, an intramedullary nail is advantageous if the initial length permits. The bone is cut and slowly pulled apart so that new bone tissue can grow back.

Length differences of approx. 6 cm or more often result in crooked posture and pain. An upper arm lengthening solves the problem. If the length of the forearm bones does not match, pain occurs in the wrist. Usually the radius is lengthened. In people of short stature, problems with personal hygiene may be the main issue, so that only a bilateral upper arm lengthening can provide relief.

On the upper arm, the radial nerve is at risk because it runs in close proximity to the bone. Damage to this nerve leads to wrist drop (loss of wrist extension). On the forearm, it is important to preserve forearm rotation (pronation and supination).

Inside the implant manufactured by Wittenstein intens (Igersheim) is a completely encapsulated electric motor. Energy is transmitted to the motor via an antenna located under the skin by placing a transmitter over it. Therefore, there are no external connections or openings in the skin after surgery. The small external control unit is easily carried by the patient, and enables safe activation of the implanted motor. Malfunctions such as unintentional or uncontrolled lengthening are not possible. The built-in motor develops considerable force and is thus able to separate the bone fragments evenly in deliberate small steps, which is particularly important for healthy new bone formation. The lengthening process itself is completely painless and not noticed by the patient. Only the tightening of the soft tissues and pressure on the joints can become painful with greater amounts of lengthening. The ultimate result is very cosmetic compared to other bone lengthening methods, since the longest scar is only about 2 cm, and normally heals almost invisibly.

FITBONE implants can perform lengthening up to 80 mm and have state-of-the-art drive technology and control functions. Lengthening greater than 80 mm require staged surgeries. The planning of deformity correction with lengthening (such as for bow legs, knock-knees, or rotational deformities of the leg) is very important, and accomplished with a planning technique (Reverse Planning Method) developed at ZEM-Germany. This planning, adapted to the FITBONE system and minimally invasive surgical techniques, permit complete correction of such deformities simultaneously, currently not possible with other implants with comparable accuracy. Even long-segment bone defects, e.g. after accidents or bone tumors, can be treated with the FITBONE system, avoiding the need for an external fixator. If both upper (femur) and lower leg (tibial) lengthenings are to be performed, one fully implantable intramedullary distraction nail is usually placed in the upper leg and another intramedullary distraction nail in the lower leg. Both implants can be inserted through a single, small skin incision below the kneecap, which later heals almost invisibly parallel to the skin folds. Since the lengthening proceeds at 1 mm/day on both the upper and lower leg, the entire leg can thus be lengthened at 2 mm/day, which leads to a significant reduction in the total treatment time.

Whenever lengthening is to be performed with or without other deformity correction of a long bone and the bone is large enough to accommodate an intramedullary nail, a FITBONE intramedullary distraction nail is an advantageous option. This applies to not only to one or both legs, but also the upper arms. Lengthening of one leg may be necessary after bone fractures or disturbed normal growth of a bone, resulting in its' shortening. Lengthening of both legs is medically indicated in cases of short stature such as achondroplasia, Turner syndrome or Silver-Russell syndrome. Lengthening of both legs can also be done using the FITBONE system in people who do not have pathological changes in their bones, but merely feel too short. In such cases, however, the costs for the entire treatment must be borne by the patient. The fully implantable FITBONE intramedullary distraction nail can also be used to rebuild missing bone that has been lost or removed, such as the result of an accident or after surgical removal of benign or malignant bone tumors.

The FITBONE intramedullary distraction nail can also be used on both the upper and lower leg in children starting at about the age of 10 if, for example, the leg length difference becomes so great that compensating shoe lifts become too cumbersome and hinder mobility excessively. However, the indication for lengthening must be studied carefully in each individual case. It is most advantageous to surgically correct leg length differences after the completion of leg growth, since the amount of difference in the leg lengths is known and won't change after that stage. Leg growth typically is finished by age 15 years in girls and 16 in boys.

Lengthening of both legs can be performed in different ways. The easiest and most comfortable way for the patient is to perform lengthening on one side, then the other, since the patient can be full weight-bearing on the sound side. To reduce the total time in treatment, simultaneous or overlapping treatment of both sides is often desired. After the first operation on the upper and lower leg of one side, surgery on the other side can be performed as early as 1 week later, although waiting 4 to 6 weeks is generally preferable. The advantages of simultaneous leg lengthening include treatment time saved and the ability to conduct physiotherapy of both legs in the same treatment sessions. However, these advantages are offset by the disadvantages that for some portion of the treatment course, the patient's mobility is restricted, with dependence on outside help and use of a wheelchair, since full weight-bearing on legs undergoing active lengthening is not allowed until the lengthened bone has hardened. The strategy of operating on both bones in both legs in the same operation is associated with a significantly increased risk of embolism and is therefore not performed at our center.

The underlying technology is the same for all FITBONE distraction nails. A high-performance electric motor drive (or motor) is always incorporated in the nail. This drive is supplied with energy by reliable, easy-to-use and digitally-controlled electronics, so that malfunctions are prevented. The most frequently-used FITBONE model is the telescopic intramedullary nail (TAA), which can be used for both the femur and tibia, with or without simultaneous correction of bone deformity. Upper arm lengthening can also be advantageously performed with the TAA model. A special capability - unique in Germany - is the treatment of high hip dislocation. In such cases, where the leg will not properly support the pelvis due to a malformed or non-formed hip joint, the FITBONE TAA can bring the leg into a correct anatomical position, so that hip joint replacement in the correct position is possible afterwards. Another unique model is the solid slidehole (SAA) FITBONE, which has already resulted in excellent treatment outcomes in thigh deformities once thought hopeless to correct. This implant not only lengthens the bone but can also close bone defects biologically. This variant is mainly used for severe, bones damaged in accidents or extreme, congenital deformities. Other model is the FITBONE-FSA, which combines some of the advantages of both systems and is used for bone defects and shortening of the upper and lower leg. Its use is reserved for special situations for which no other implants were previously available. The FITBONE intramedullary distraction nail finds special application in combination with so-called growth prostheses (MUTARS) in children. Malignant bone tumors (bone cancer, osteosarcoma, Ewing's sarcoma) mainly occur near joints, particularly around the knee, during growth. In affected children, their own joint usually has to be resected (usually with the growth areas of the affected bone) and replaced by a joint prosthesis. As the other leg continues to grow, a difference in leg length will develop due to loss of the growth area, and this difference has to be compensated for. Until now, lengthening the bone or the prosthesis after tumor surgery was not feasible, so that these children had to endure a lifetime of cumbersome braces or shoes with lifts, or undergo disfiguring operations. The FITBONE Intramedullary distraction nail can lengthen both the prosthesis (Xpand) and the remaining bone (BioXpand), an innovation from ZEM-Germany in cooperation with the company Implantcast (Buxtehude) that opens up completely new perspectives for the affected children.

Any leg lengthening in adulthood involves surgical cutting of the bone to be lengthened into two fragments, stabilization of the fragments, and gradual separation of the bone fragments after surgery. Even though the FITBONE system is the safest treatment option in our experience, all lengthening surgery techniques entail some risk of complication. Risks of a general nature include post-operative bleeding, vascular and nerve injuries, muscle and joint dysfunction, problems with wound healing and thromboses. With any type of intramedullary nailing, there is also a risk of pulmonary embolism, as the fatty marrow may be dislodged from inside the long bones. Although the risk of infection is significantly higher during lengthening treatment with an external fixator, infection can also occur after implantation of an intramedullary distraction nail, just as after any operation. Under certain circumstances, the bone fragments may have to be stabilized from the outside, at least temporarily. Such complications are extremely rare at ZEM-Germany, well below 0.1%. Slow formation of new bone in the distraction gap during lengthening may occur, particularly in the lower leg (shin, or tibia), as the blood supply to the bone is reduced here due to a smaller amount of soft tissue encasing the tibia, particularly in the front. If bone formation in the distraction gap is inadequate to allow full weight-bearing, some cancellous bone from the iliac crest (pelvis) may have to be grafted into the distraction gap (cancellous bone grafting), after which the bone will typically solidify within 6 weeks. This measure may be necessary in up to 15% of cases, especially with previously damaged bones or in people who smoke.

The FITBONE distraction nail receives energy "transcutaneously" through intact skin. The FITBONE receiver is responsive only to the energy provided by the control unit. This means that neither your mobile phone nor any other electronic device can influence the function. Compared to magnetically driven intramedullary nails (Precice), the control unit is handy, lightweight, and easier to use because no magnets are required and the coupling always works reliably, even with a somewhat stronger soft tissue sheath. The FITBONE is also the only implant where the patient has an immediate check whether the lengthening process has actually taken place. In summary, FITBONE implants with their control and monitoring functions offer maximum safety and comfort.

The patented Xpand growth prosthesis is a tumor endoprosthesis with a FITBONE distraction nail drive inside. After removal of an osteosarcoma or Ewing's sarcoma In children, these prostheses can be used to compensate for a leg length difference which develops from decreased growth in the operated leg compared to the opposite side by lengthening the prosthesis body. The Xpand growth prosthesis appropriate for adolescent patients, starting about the age of 12. In younger children whose leg length inequality will be greater because of more substantial difference in the amount of growth the of the operated leg compared to the opposite after tumor removal surgery, the BioXpand is much more advantageous. With these innovative growth prostheses, developed at ZEM-Germany, new bone can be created, as it is not the prosthesis body that is lengthened, but the remaining bone.

MUTARS BioXpand represents a quantum leap in the development of growth prostheses, as this endoprosthesis allows bone growth for the first time even with a tumor endoprosthesis in place. This developmental leap is due to the fact that the FITBONE intramedullary distraction nail does not lengthen the prosthesis but rather the remaining bone by the callus distraction method. The greater bone length created by this method results in improved anchorage possibilities and thus significantly more stability for the prosthesis.

The BioXpand was patented in 2006 and used in a patient for the first time in the world at ZEM-Germany in 2007. The first cases resulted in previously unimaginable success, stimulating further developments and improvements in the system. The basic principle of the BioXpand, to grow the bone instead of the prosthesis, is used in all models of BioXpand. With the initial model, BioXpand I, changing from the initial polished stem to a FITBONE intramedullary distraction nail and any further exchange, e.g. to the definitive ingrowing stem after growth is complete, requires exposing or even changing the prosthesis, and is thus a "major" surgical procedure. While retaining all the advantages of BioXpand I, BioXpand II now only requires minimal surgical access, as all replacement procedures are carried out from the side facing away from the joint via small skin incisions (max. 3 cm) and the prosthesis itself remains virtually untouched. In addition to simplifying revision surgery, the risk of infection is drastically reduced. Initially, BioXpand II was only available for use in the femur (thigh). Plans and first prototypes (BioXpand III) already exist at ZEM-Germany that will allow all follow-up operations, including exchanges in the lower leg, to be performed without renewed major surgical access in the area of the prosthesis.

In principle, it is always possible to change to a BioXpand if this results in a meaningful improvement in the treatment options for the affected child. If a polished stem has been inserted, implant exchange is relatively straightforward. However, if the primary prosthesis was inserted with coated stems that grow firmly into the bone, the indication for implant exchange must be considered very carefully, as removal of these stems is only possible in an extremely invasive and costly manner. It is therefore all the more important to choose a surgical treatment strategy from the outset that does not make subsequent treatment more difficult or even impossible. Therefore, you should also seek advice at ZEM-Germany before reconstruction surgery, if the tumor operation is to be performed in another clinic.

The greatest danger when using tumor endoprostheses of any type is infection. Infections can also occur with growth prostheses, especially if several replacement operations are necessary. However, the BioXpand II and the in-development BioXpand III drastically reduce the risk of infection, as large surgical exposures are no longer required directly in the area of the prosthesis.

In the case of malignant bone tumors, the complete removal of the bone tumor and the surrounding soft tissues remains the priority during the initial operation, as the survival of the patient depends on this. If the decision has been made to use a MUTARS BioXpand, an interim prosthesis with "smooth, polished" stems should always be used during the initial operation, which initially ensures optimum stability and keeps subsequent reconstruction options open. It is also important to bear in mind that children are weakened by preoperative chemotherapy and ultimate prognosis is not yet clear. Currently, the MUTARS BioXpand II is available for the thigh and lower leg with polished and thus exchangeable stems; at least for the most frequent tumor site, the distal thigh, it already allows minimally invasive lengthening. In the future, the BioXpand III, also with polished stems, will enable lengthening procedures in the thigh and lower leg by minimally-invasive techniques, a prospect that seemed unthinkable until recently.