Orphopedic Device for Extremities
Development and Clinical Trials of Automatic Compression and Distraction Device of External Fixation for Lengthening of Extremities
Tech Area / Field
- MED-DID/Diagnostics & Devices/Medicine
8 Project completed
Senior Project Manager
Alexandrov K A
VNIIEF, Russia, N. Novgorod reg., Sarov
- Scientific and Research Institute of Traumatology and Orthopedics, Russia, N. Novgorod reg., Sarov
The lengthening of shortened extremities, despite of significant achievements in this area of orthopedics till now remains a actual problem requiring solution at new theoretical and technological levels [6, 7, 10].
Nowadays Russian orthopedics saves advanced positions on a problem of lengthening of the extremities as follows from the long-term analysis of the global professional literature [6, 3]. The observance of Ilizarov’s method principles of lengthening of extremities (rigidity of fixing bone fragments, low traumatization of operating interference, fullness of blood supply of a elongating segment, optimal rate and rhythm distraction, functional load extremities) allows to achieve positive results in 99,8 of cases worked out as a result of long-term use 6. Ilizarov’s device has a greater rigidity of fixation of bone fragments in comparison with similar devices, that allows to make the elimination of complex multiplanar deformations alongside with lengthening of a segment [1, 13]. Carried out transosseous Kirshner wires practically do not break blood supply of bone fragments. The universality of the device allows to create inpidual subroutine linkages for solution of the concrete clinical tasks. Nowadays Ilizarov’s method is used in many countries of the world, including USA, Italy, France, Germany, Poland, Macedonia, Brazil, Mexico, India [3, 7, 11, 12, 13].
One of the urgent tasks of lengthening of the extremity, requires theoretical and practical solution, is the choice of optimal differentiated rate of distraction depending on inpidual features of a patient, maximum rise of the fraction of distraction with possibility of transition to smooth continuous distraction with the help of automatic devices. The advantages of automatic distraction are conclusive [1, 4, 5, 6, 8, 9, 10]. High fraction distraction (1 mm for 60 and more impulses per day) in comparison with hand-operated (1 mm for 4-6 receptions) approach the process of lengthening of the extremity to natural physiological growth. Thus there are no jumps of distraction forces, which cause the constant micro-traumatiszation and irritation of muscular-nervous system, nervous and vascular trunks, that results to undesirable trophesial reactions which response to constraining the process of regeneration. Other words create favourable conditions for regeneration of the tissues.
Nowadays several variants of the automatic distraction devices are created (patent of the USSR №№ 848011, 865284, 1122308; patent of the USA №№ 4615338, 4973331). First automatic distraction device was created and is applied in 1979 in Gorky, nowadays Nizhny Novgorod, Science-Research Institute of Traumatology and Orthopedics by the professor S. Vvedensky (patent of the USSR № 848011). The device of external fixation with an original electromechanical drive had highly fractional rhythm of distraction (1 mm per day for 8640 impulses). The number of design features, including absence of sufficient synchronization of 3 drives, complicated the full usage of the device and limited it application in wide practice. Created in Russian Science Center “Rehabilitation Traumatology and Orthopedics” in Kurgan the devices that allow to install limited fraction of the distraction rhythm (1мм per day for 60 impulses), are deprived of sufficient synchronization, they can’t provide the exact stable rhythm of distraction, that limits the range of clinical application in wide practice. Those devices are have no any feedback system, allowing to self-regulate distraction forces and velocity of lengthening.
The development, technical and clinical trials of a new automatic distraction device of external fixation for lengthening of the extremities, deprived of constructive set forth above disadvantages is planned within the framework of the prospective project. It is supposed to develop and fabricate the device having a high degree of synchronization on all 3 distraction rods, high degree of a reliability capable to develop distraction force up to 1000 Н, ensuring dosed highly fractional rhythm of micro-distraction (0,1 - 2,0 mm per day for 10000-20000 impulses). The new device will provide the possibility of long and safe operation of the device in automatic regime on the basis of controlled step motor with autonomous electric powering; it will be equipped with microprocessor and feedback system, providing self-regulation of the distraction forces, velocity of lengthening of the extremity. This device will allow to inspect and to operate the regeneration of tissues with maximum possibility, to eliminate trophesial complication, to avoid the development of released range of motion of adjacent joints, to lower an amount of infectious complications, to reduce considerably periods of treatment, to expand boundaries of possible lengthening. The process of lengthening of extremity will come nearer to natural physiological growth at maximum. In overall it will lead to the significant social and economical effect.
After technical trials it is planned to apply the device of a new construction at 10 patients with lengthening of cruse and femur. For the purpose of the control of the process of regeneration the following methods will be used: X-ray, ultrasound examination of the callus (definition of structure and degree of mineralisation of a callous) electromyography (control of a state neuromuscular system), rheovasography (blood supply control of a elongating segment). Dynamics of a content of somatotropin, parathyroid hormone, alkaline and sour phosphate, calcium and phosphorus in the whey of blood describing creation and modification of the callus also will be defined.
The results of researches will be published in scientific journals and reported on conferences of an international level. After the completion of the project new automatic distraction device and technique of lengthening of extremities will be recommended to wide application in practice. Wide experience and high qualification of the employees of Federal Nuclear Center of Russia – All-Russian Science-Research Institute of Experimental Physics and Nizhny Novgorod Research Institute of Traumatology and Orthopedics (30-year's experience of lengthening of the extremities), involved for the execution of the given project, good scientific, technical and clinical base of establishments are a pledge of successful execution of the project.
1. Vvedensky S.P. Clinical and biomechanical substantiation and differentiated application of methods of lower extremity lengthening: Аutoabstract of Dissertation of Doctor of Medical Sciences. - М., 1983. – 29 p.
2. Vvedensky S.P. Thirty-year’s experience of transosseous osteosynthesis by Ilisarov method // The Genius of orthopaedics. - 1996. – № 2-3. - P. 25.
3. Diachkova G.V. Ten years of a Ilisarov method in USA // The Genius of Orthopaedics. - 1996. -№ 2-3 - P. 19-22.
4. Ilizarov G.А. Etc. Experimental - clinical aspects of the extremity lengthening in an automatic mode / G.А. Ilizarov, S.А. Еrofeev, А.V. Popkov etc. // The Materials of VI congresses of traumatologists and orthopaedics A CIS on September 14-17. - Yaroslavl, 1993. - P. 363-364.
5. Ilizarov G.А., Kamaev I.А., Shreiner А.А. Possibilities of automatic control of the distraction process // Treatment of the orthopedic and traumatologist patients in clinic and polyclinic by a transosseous osteosynthesis method, developed in КNNIIEКОТ - theses of the reports All-Union science - practical conference. (January 27-28, 1982), p. II. - Kurgan, 1982. - P. 21-23.
6. Popkov А.V. Operative lengthening of the extremities by a method of transosseous osteosynthesis: contemporary situation and perspectives // Traumatology and orthopedics of Russia. - 1994. - № 2. – P. 135-142.
7. Popova L.А., Timopheev V.N. The inventions in Traumatology and orthopedics: structure, dynamics, main directions // The Genius of Orthopedics. - 1996. -№ 2-3 - P. 29-30.
8. Chirkova А.М., Еropheev S.А. X-ray morphology aspects of the osteoreparation in the cases of automatic distraction // Traumatology and Orthopedics of Russia. - 1994. - № 2. - P. 142-148.
9. Shevzhov V.I., Popkov А.V., Еropheev S.А., Chirkova А.М. The automatic distraction osteosynthesis // The Annals of Traumatology and Orthopedics. - 1995. - № 1. - P. 44-47.
10. Shevzhov V.I., Popova L.А. The main perspective directions in the development and perfecting of a Ilizarov method in clinical practice // Traumatology and Orthopedics of Russia. - 1994. - № 2. - P. 18-21.
11. Grill F; Dungl P. Lengthening for congenital short femur. Results of different methods. // J Bone Joint Surg, Br, 1991, May; 73(3):439-47.
12. Rajewsky F., Marcinak W. Use of Ilizarov distraction modified by Cattaneo and Catagni for femoral lengthening // Chir Narzadow Ruchu Ortop Pol. – 1993 – 58(6) – P. 475-480.
13. Vidal J. et al. Fixation externe: “a la recherche de la meilleure stabilite” – Apres 17 ans d’experience / J. Vidal, J. Adrey, H. Connes et al. // Rev. Chir. Orthop. – 1983. – V. 69, № 5. – P. 372-375.