Principle of tension band wiring n its application

A small but powerfull presentation

1. PRINCIPLE OF TENSION BAND AND ITS APPLICATION IN ORTHOPAEDICS MODERATOR: PROF. DR. M.S. DHILLON PRESENTED BY: DR. ROHIT KANSAL

2. OVERVIEW INTRODUCTION HISTORY CONCEPT OF TENSION BAND TYPES APPLICATION TENSION BAND WIRING TENSION BAND PLATE COMPLICATIONS

3. introduction The tension band technique converts a tensile force into a compressive force. Enables improved fracture healing, as stability is improved when tensile forces are reduced at the fracture site.

4. What is a Tension Band A tension band is a device which exerts a force equal in magnitude but opposite in direction to an applied distracting tensile force REF: MANUAL OF INTERNAL FIXATION BY M.E. MULLER 3 RD EDITION

5. HISTORY The tension band concept was introduced to orthopedics by Freidrich Pauwels in the 1930's and was applied to internal fixation of eccentrically loaded bone

6. He observed that :   An eccentrically loaded bone has a tension and a compression side .

7. A tension band converts tension into compression at the opposite cortex

8. CONCEPT OF TENSION BAND IN DETAIL The schematic diagram shows an I-beam connected by two springs. There are two small pulleys on the left side . Pulley Spring

9. Central Axial loading Compression force is equally distibuted across the surface

10. Eccentric loading TOTAL STRESS= DIRECT + BENDING STRESS COMPRESSION FORCE TENSILE FORCE

11. Eccentric loading wid Tension Band IF A TENSION BAND IS APPLIED PRIOR TO THE ECCENTRIC LOADING, IT RESIST THE TENSION THAT WOULD OTHERWISE STRETCH THE OPPOSITE SPRING N THUS CAUSES UNIFORM COMPRESSION OF BOTH SPRING.

12. Antero-lateral surface TENSION Postero -Medial surface COMPRESSION Femur is an eccentrically loaded bone, which is bowed both in :- Coronal plane Saggital plane In curved long bones like femur which are eccentrically loaded, the convex side of the diaphysis indicates the tension side.

13. Which are the eccentrically loaded bones of the body ??? Tubular Long bones :- Femur Humerus Radius Ulna In general, the concave surface acts as the compression surface and the convex as the tension surface.

14. PREREQUISITES for tension band Tension band must be applied on the tension surface of the bone. Must be prestressed (tightened). Must be strong to withstand tension load. Strong opposite bone cortex must be present to withstand dynamic compressive loads. Joint movement must be encouraged to improve congruity n compression.

15. PRESTRESSING OF TENSION BAND KEEP THE FRACTURE FRAGMENT UNDER STATIC COMPRESSION.

16. IMPORTANCE OF INTACT OPPOSITE CORTEX IF TENSION BAND IS APPLIED ON THE FRACURE SITE WITH DEFICIENT MEDIAL CORTEX , MEDIAL CORTEX WILL FURTHER COLLAPSE N WILL ULTIMATELY LEAD TO IMPLANT BENDING N FAILURE

17. What all devices can act as tension bands ??? Stainless steel wire either alone or in combination with K-wires and/or Screws Plates External fixators M etal cables Non absorbable Polyester sutures ( Ethibond )

18. A tension band that produces compression at the time of application is called a STATIC TENSION BAND , as the forces at the fracture site remain fairly constant during movement. Tension band application to the medial malleolus is an example of a static tension band. STATIC TENSION BAND

19. EXAMPLE OF STATIC TENSION BAND MEDIAL MALLEOLUS

20. If the compression force increases with motion, it is known as DYNAMIC TENSION BAND A good example is the application of the tension band principle to a fracture of the patella. Upon knee flexion, the increased tensile force is converted to compression force. DYNAMIC TENSION BAND

21. Patella Olecranon EXAMPLES OF DYNAMIC TENSION BAND

22. Gr. Tuberosity of humerus Gr. Trochanter of femur DOUBT......

23. CONCEPT OF APPLICATION (REF: AO PRINCIPLE OF FRACTURE MANAGEMENT) The tension band principle with wire loops is often applied to articular fractures of the patella and olecranon, converting tension from muscle pull into compressive force on the articular side of the fracture.

24. 2. Small avulsion fractures may benefit from the principles of tension band fixation. A tension band can reattach the avulsed fragment, convert tensile force into compression force allowing immediate motion of the joint. Greater trochanter avulsion

25. Bones subjected to Eccentric pull of tendons/ligaments also have tensile forces n compressive forces acting on its surfaces Olecranon process of ulna Patella Greater tuberosity of humerus Greater trochanter of femur Medial and Lateral malleoli of tibia Phalanges near attachments of tendons/ligaments Tibial tuberosity at patellar tendon insertion

26. 3 . The principles of tension band fixation with a plate can also be applied in diaphyseal fractures such as the femoral shaft. 4. Similarly, in delayed bony unions or in nonunions , where the presence of angular deformity creates a tension side in the bone, adherence to the tension band principles becomes extremely important .

27. Tension band wiring TBW is a fixation technique which results in ABSOLUTE STABILITY Therefore, Interfragmentary compression n direct bone healing is obtained. (REF: AO PRINCIPLE OF FRACTURE FIXATION)

28. ABSOLUTE STABILITY No movement at fracture site. Interfragmentary compression. No callus formation. Direct bone healing. Eccentric articular fractures Ex:lag screw , tension band ,compression plates RELATIVE STABILITY Movement at fracture site. Bridging or splinting. Callus formation . Indirect bone healing. Diaphyseal fractures. Ex: Intramedullary nail, internal fixator n external fixators . GRABBB IT!!!

29. TENSION BAND WIRING REF: THE ELEMENT OF FRACTURE FIXATION BY ANAND J.THAKUR, 2 ND EDITION, CH-7 A wire , a cable or a non-absorbable suture is used to perform the function of a tension band. Usually wires from 0.4 to 1.5 mm are used. A 1.2mm wire is used as a tension band. Tension band wire is often applied in a figure of 8 fashion around previously inserted, parallel n longitudinally place kirschner wires, steinmann pins, or cancellous lag screws.

30. POINTS TO REMEMBER!!! Implants like steinmann pin, cancellous screw, n k-wires are used as an adjunctive fixation wid TBW to prevent displacement of the fracture fragments through shearing , translation, or rotation . Crossed k wires are less stable and interfere with interfragmentary compression. The parallel k wires also provide anchorage points around which the tension band wire is placed.

31. Occ, the TBW may be used without the k-wires, as in the fixation of a transverse fracture of the patella where an irregular fracture line allow perfect reduction by interdigitation of the fracture surfaces.

32. UNUSUAL SITES FOR TBW (REF: ELEMENT OF FRACTURE FIXATION BY ANAND J THAKUR, 2 ND EDIT, CH 7) Lateral end of clavicle . Efffective method of securing small fragments. chances of migration of k wire to vital organs are high. 2. DIAPHYSIS OF METACARPAL N METATARSAL For isolated metacarpals or metatarsals

33. 3. ARTHRODESIS OF THE THUMB when the two phalanges are quit small and the bone is porotic . 4. ARTHRODESIS OF WRIST In porotic bone stock, plating is impossible n TBW is a viable option

34. TENSION BAND PLATE When a plate is applied as a tension band on the lateral(tension) side of the bone the neutral axis shifts from the center of the bone to plate bone junction. ( REF:THE ELEMENT OF FRACTURE FIXATION BY ANAND J THAKUR, 2 ND EDIT, CH:4)

35. Any axial loading produces tension in the plate n distributes pure compression forces across the fracture line The load is shared by plate n the bone

36. “ A bone will act as a tension band only if it is applied to the tension side of a bone”

37. When a plate is applied as tension band in the bending close construct, the working lenght for bending of plate is minimal, since it is in contact with bone on either side of fracture. BENDING FORCE

38. The plated bone is particularly weak under loads that tends to bend open the fracture.The working lenght of a plate is greater in bending open construct .

39. Use of external fixator as tension band Clinical example of an external fixator acting as a tension band in a nonunion after intramedullary nailing . REF: AO PRINCIPLE OF FRACTURE MANAGEMENT Symptomatic nonunion with nail in place—note the hypertrophic area on the posterior side of the tibia and the gap anteriorly .

40.   After removal of the intramedullary nail, a unilateral external fixator was applied anteriorly in the sagittal plane, and full weight bearing was encouraged. The nonunion consolidated .

41. Complication can be: 1 . IMPLANT FAILURE Due to wrong indication Osteoporotic bone Comminuted opposite cortex Gap or defect in opposite cortex Weak implant Prebending of plate not done 2. Joint stiffness Due to deficit in flexion n extension Strong capsule n ligament due to injury PITFALL AND COMPLICATION

42. PREBENDING PREBENDING OF PLATE

43. REMEMBER!!! A wire put under pure tension is very strong. However, if bending forces are added, it will break quite rapidly due to fatigue. This principle of fatigue failure also holds true for plates .

44. 3) HARDWARE PROMINENCE Is a common patient problem associated wid tension band fixation may also l/t skin breakdown n subsequent infection. Wire prominence is usually related to improper k-wire seating at the time of surgery. The tips of the k-wires should be U-bent, shortened n impacted in the bone

45. 4)Another occasional complication seen wid tension band wire for olecranon fracture is its cutting out of the distal fragment if the wire is not inserted deep enough below the dorsal cortical surface of the ulna.

46. THANK YOU