Tibial Hemimelia (tibial reduction deficiency) is a very rare birth defect that occurs one in every million births. It is characterised by different amounts of reduction of the tibial bone, up to a complete missing bone. This malformation can appear with a cartilaginous anlage (remnant of missing tibial part made of cartilage) or without. With the occurrence of the missing tibial part the adjacent joint (knee or ankle) is also non-existent. Children with this rare birth defect are not able to walk on the affected leg or if both legs are affected, not able to walk at all. The usual therapy for such children is to support walking with orthoprosthetics or after amputation of the affected limb with prosthetics. This malformation is the most challenging for orthopaedic surgeons to treat. Dr. Sulaiman Al Habib Hospital in Dubai Healthcare City is in forefront for introducing latest technology available across the globe to Dubai.
For children born with these congenital disabilities, world-renowned orthopaedic surgeon Dr. Michael Weber has developed unique techniques for each of the disabilities (see fig. 1) not only to prevent amputations, but also to enormously improve the function of the limbs and, therefore, life quality of the children. Dr. Weber is also a professor of orthopaedics and the faculty member of the internationally acclaimed University of RWTH in Aachen, Germany. He has invented the “Transformations Surgery” and “Booster Surgery” for these malformations.
Weber’s Transformation Surgery
Weber’s Transformation Surgery means the conversion of a useless anatomical structure of the disabled limb into a useful anatomical structure. For example, the transformation of the fibula into the function of a tibia, or a knee cap (patella) replacing the part of a missing joint (see figs. 2-4). Once an anatomical structure has been transformed into a useful function, automatically, this structure develops the form intended. This extraordinary principle of “form follows function” works only in childhood. Therefore, the younger the children, the better their biological capacities and biological response and outcome to the Transformation Surgery.
Weber’s Booster Surgery
Weber’s Booster Surgery is the enhancement of sleeping growth potential of the cartilaginous anlage. Professor Weber was the first in history who discovered the existence of the cartilaginous anlage in tibial hemimelia. This cartilaginous anlage is a remnant of the developing tibia in the fetus that still has growth potential, if you know how to stimulate it. If there is no stimulation, the cartilaginous anlage wastes away. Dr. Weber found a way to boost the growth potential of the cartilaginous anlage by bringing them into contact with their joint partners. With this unique technique, the cartilaginous anlage forms the missing joint part, and with its own growth plate later maturates into a tibial bone. The use of the cartilaginous anlage in tibial hemimelia is a breakthrough in the construction of missing joints and recovery of the original growth plates of the affected limbs (see figs. 5 and 6).
With this technique, Dr. Weber has given the malformed limb the chance to complete the missing parts in the fetal growth. This spectacular technique can be used to construct the missing tibial parts and the joints for five different types of tibial hemimelia (Types IIIa, IVa, Va, VIa and VIIa of Weber-Classification, see fig. 1).
Worldwide success of the Weber technique
Professor Weber has treated patients worldwide with this rare disorder. According to his classification of tibial hemimelia (fig. 1) Dr. Weber has invented a unique technique for each of the 12 different types. These techniques are the most successful worldwide. For the discovery of these innovative techniques, Professor Weber was awarded by the German and the European Society for Paediatric Orthopaedics.
Fig. 1. Weber-Classification of tibial hemimelia characterised in seven types and five subgroups (a = with cartilaginous anlage, b = without cartilaginous anlage) according to the severity of the malformation. Black = bone, blue = cartilaginous anlage and red circle = tibial defect without cartilaginous anlage. Hypoplasia = all limb structures present but underdeveloped. Diastasis = malformation of ankle joint where the foot is pushed between the two bones of the lower leg. Distal Aplasia = the lower part of the tibia is missing. Proximal Aplasia = the upper part of the tibia is missing. Bifocal Aplasia = the upper and lower part of tibia is missing, only a central part of tibia is present. Agenesia = total missing of tibia.
Fig. 2. Schematic drawing of knee construction, transforming the knee cap (patella) into tibial plateau, the knee capsule – beside its original function – into collateral ligaments and the fibula into tibia. (1.) Drawing of the incisions (red dotted lines a, b, c) into knee capsule (blue circle) required for creation of two visor flaps based medially and laterally. The quadriceps tendon is lengthened in Z-plastic manner and sutured end to end after visor flaps shift. (2.) In order to bring the knee cap into the position of a tibial plateau, the visor flaps have to be crossed contra rotating and sutured. The knee cap is connected to the fibular head.
Fig. 3. The transformation of fibula into tibia and the knee cap (red) into tibial plateau (joint) demonstrated in a lateral view of the limb. (a.) The X-ray shows the right leg before surgery at 12 months. Note the small size of the fibula in comparison to the index finger. (b.) Schematic drawing of the limb before surgery. No tibia is present, there is no knee joint and ankle joint and the fibula has no function. (c.) After soft tissue lengthening with a ring fixator the fibular head can be placed under the femur and the foot under the lower end of the fibula with an acute maneuver via surgery. (d.) At the same surgery the knee cap shift via the double visor flaps is performed bringing the knee cap into position of a tibial plateau. Now the knee cap can work as a joint partner for the femur. The knee cap is fixed to the fibula. The foot is stabilised under the lower end of fibula. (e.) The X-ray of the same leg one year after surgery. Note the tremendous size increase of the fibula (“form follows function”) in comparison to my index finger.
Fig. 4. (a) The child had all four limbs malformed. (b) After lengthening with a mini-ring-fixator and performing the Weber Transformation Surgery (patella > tibial plateau, fibula > tibia) for creating a knee joint and a tibia on the right leg, the patient now has full weight bearing with very good range of motion (c) The affected left leg was also treated successfully. Worldwide this technique is the only procedure preventing lower extremity limb amputation in children suffering from type VII-b Tibial Hemimelia. The treatment of the hands was performed later and subsequently the boy was able to play soccer (d). The boy is now 25 years old, he is able to ski in the Austrian mountains, is a voluntary-firefighter and has studied in America.
Fig. 5. Schematic drawing of operational procedure of type-Va tibial hemimelia.
(a) X-ray of a leg in a 10-month old girl before procedure.
(b) The tibial remnant has no contact to the joint partners of femur and foot.
(c) After cut of tibia the bone wants to heal and produces callus. The callus is soft and can be distracted (callus distraction). Both bone parts with the adhering cartilaginous anlage are transported towards their joint partners.
(d) The gap between the cartilaginous anlage of the upper tibia and the femoral condyles as well as lower tibia and the talus (bone of foot) is closed by bi-directional bone transport.
(e) The distracted callus maturates into full quality bone.
(f) X-ray of the same leg one year after first lengthening. Patient has full weight bearing, very good joint functions and can walk and run.
Fig. 6. Same patient as in Fig. 5.
(a) The malformed leg and foot before surgery. The additional toe has to be removed to enable the patient to wear shoes
(b and c). Ring fixators are stabilising the leg during lengthening process.
(d and e) The X-rays show the creation of knee and ankle joint including 400 per cent lengthening of tibial remnant after two lengthenings. The leg length discrepancy is fully equalised. The patient is wearing normal shoes.
The case of a child from Abu Dhabi
A child from Abu Dhabi was suffering from a Weber-Type-IIIB tibial hemimelia of his right leg without cartilaginous anlage and severe deformities on his foot (see fig. 1). His parents desperately tried to find a surgeon capable of treating such a malformation. The answer they got from most surgeons in the UAE was to amputate the leg. They tried everything to avoid amputation and were willing to go to the USA in order to get another treatment option. The parents were amazed to find out that the specialist in USA was using successfully, the techniques invented by Professor Weber from Germany. To their surprise they discovered that he actually worked in Dubai, performing these specialised surgeries at the Sulaiman Al Habib Hospital in Dubai Healthcare City.
First meeting with Professor Weber: Amputation not recommended
On their first meeting with Professor Weber, the parents were relieved to find that he had successfully treated patients worldwide for 25 years, the longest experience worldwide. They were reassured by Professor Weber that amputation was not recommended and the boy would walk and even play soccer after a couple of planned surgeries with the special Weber techniques.
For the first time the parents felt that their son was in the best hands and that their prayers were heard. They were told by Professor Weber that the treatment would take seven to nine months with a fixator which would ensure the stability of the leg and allow all corrective procedures. They were told that with the fixator, their son would learn how to walk. After the removal of the fixator the leg would be of the same length as the healthy leg. With intensive physiotherapy the child would be able to walk and run on his own with a functioning knee joint. And after numerous exercises, he would even be able to play soccer.
Getting the kid back on his feet
All of this has come true. The child can now walk on his own and is playing soccer. The operated leg was first protected with an orthotic brace until the stability of the bone increased and the knee reached its full function. Now he doesn’t need the brace anymore and is happy to walk, run and play soccer with shoes.
