1. Fractures of the olecranon and the patella
Published: July 2013
Brian Bernstein, ZA
AOT Basic Principles Course

2. Learning outcomes
Explain the tension band principle for fractures of the olecranon and patella
Discuss the limitations and complications of tension band wiring (TBW)
Describe surgical techniques used in the treatment of patellar and olecranon fractures
Define alternative techniques when TBW is not possible

3. Tension band situation
Force applied eccentrically causes tension and compression within the column
Tension absorbed/converted by a band
Compression absorbed by a strong buttress

4. Tension band principle
“In relation to long bones there is generally a tension side and a compression side.” Pauwels

5. Tension band principle
Conversion of the tensile forces across a fracture into compressive forces
Fixation device placed eccentrically on tension side of fracture
If we understand the biomechanical principle described by Pauwels in relation to the tension and compression sides of a long bone, and apply this to areas of eccentric muscle action, we will understand the principle behind the tension band wire.

6. Tension band principle
Dynamic or static (“dynamic” absolute stability)
Articular fractures where muscle pull will distract the fragments
Avulsion fractures
Diaphyseal fractures where there is a tension and compression side
The application of a tension band to a mobile part of the body confers neither absolute nor relative stability, rather a form of “dynamic” absolute stability whereby contraction causes resultant compression at the fracture site.

7. How does it work?

8. What does this mean We can convert destructive forces
into constructive forces

9. Indications Olecranon (dynamic) Patella (dynamic)
Tuberosity of humerus (dynamic)
Medial and lateral malleoli (dynamic)
Trochanter of femur (dynamic)
Diaphyseal fractures (static)
Common areas where principle applies.

10. Tension band construct
External fixation applied on the tension side of a bone will act as a tension band construct.

11. Exo / plate

12. Greater tuberosity
Tension band application applying compression to a greater tuberosity fracture

13. Olecranon and patellar fractures
Treatment goals
Restoration of articular surface
Preservation of power of extension
Joint stability
Preservation of range of movement
Avoidance of complications

14. Olecranon and patellar fractures
Conservative treatment
Undisplaced fractures, ie, articular separation < 2 mm
No displacement with flexion
Active extension
BUT:
Articular fractures are best treated with absolute stability

15. Tension band principle

16. Classification of displaced olecranon fractures
AO Müller Schatzker

17. Olecranon fractures Recent development of anatomical locking plates
Tension band wire (TBW)

18. Olecranon
Conversion by TBW

19. Parallel K-wires
Tension on both sides of the band
Secure medial buttress

20. Displaced olecranon—transverse fractures
43-year-old, slipped on ice

21. Displaced olecranon—oblique fractures
Primary fixation with interfragmentary lag screw and supplementary TBW

22. Displaced olecranon—complex fractures
Require tension band plate—one-third tubular/reconstruction plate/locking plate

23. Displaced olecranon—complex fractures
54-year-old, fell off ladder
One-third tubular plate cut at a hole to make spikes

24. Displaced olecranon—complex fractures
One-third tubular plate
Additional TBW

25. Displaced olecranon—complex fractures
29-year-old, motorcycle accident
Reconstruction plate

26. Displaced olecranon—complex fractures
Reconstruction plate
Postoperative

27. Displaced olecranon—complex fractures
6 months:
Full rotation
Full flexion
20°extension
Normal function

28. Displaced olecranon—complex fractures
80-year-old woman
Complex and osteoporotic

29. Anatomical locking plate

30. Displaced olecranon fractures
Management depends on fracture pattern
Simple transverse—TBW
Simple oblique—TBW + lag screw
Complex—tension band plate (locking) + TBW
Multifragmentary involving dorsal cortex
Fracture distal to articular surface
Fracture dislocation

31. Patellar fractures Articular fractures
Part of the quadriceps mechanism
Complex fractures may require patellectomy

32. Patellar fractures

33. Patellar fracture classification

34. Patella
The tension band principle applies in the same manner as for the olecranon, by converting the distraction force when contracting the quadriceps muscle in dynamic compressive force across the fracture.

35. TBW using two K-wires
Early AO manual operative description.

36. Displaced patellar fractures

37. Displaced patellar—transverse, simple fractures
39-year-old, tripped

38. Displaced patellar—transverse, simple fractures
39-year-old, tripped

39. Displaced patellar fractures—multifragmentary (stellate)

40. Displaced patellar fractures—multifragmentary (stellate)

41. Displaced patellar fractures—multifragmentary (stellate)
Alternative fixation with cannulated screws and associated tension band applied through screws.

42. Displaced patellar fractures—multifragmentary (stellate)
47-year-old, fell on steps

43. Special application distal pole fractures

44. Distal pole patellar fractures—repair of patella tendon support

45. TBW supporting tendon repair

46. Displaced patellar fractures—partial patellectomy

47. Displaced patellar fractures
Total patellectomy
< 25% good/excellent result
Preservation of one quarter will improve results
References:
Scott JC. Fractures of the patella. J Bone Joint Surg Br Feb;31B(1):76-81
Einola S, Aho AJ, Kallio P. Patellectomy after fracture. Long-term follow-up results with special reference to functional disability.
Acta Orthop Scand Aug;47(4):441-7.
Wilkinson J. Fracture of the patella treated by total excision. A long-term follow-up.
J Bone Joint Surg Br Aug;59(3):352-4.

48. Take-home messages
Tension band fixation is a technique not a device and the device required depends upon the fracture type.
TBW is recommended for simple transverse fractures, although additional lag screws/cerclage wires will extend its indications.
Complex fractures require alternative techniques:
Tension band plate
Partial patellectomy
Avoid total patellectomy