Management during surgery for medial tibial bone defect during TOTAL KNEE REPLACEMENT (TKR)

1. Ammini 65 yr old
B/l OA Knee more on left
severe varus deformity of
left

4. Bone loss in
upper tibia

6. Bone graft from femur
Multiple burr
drill holes

7. Bone graft from
femur fixed with
a screw

8. Implant
placed over
the bone
graft
Bone graft from
femur fixed with
a screw

9. Final picture
after cementing
Bone graft from femur
fixed with a screw

11. Corrected
varus after
surgery

12. MANAGEMENT OF BONE
DEFICIENCY IN TKR
DR.SIYAD AHAMMAD
JUNIOR RESIDENT IN DEPT. OF ORTHOPEDICS
GOVT. TD MEDICAL COLLEGE ALAPUZHA

13. CAUSES
 arthritic angular deformity,
 condylar hypoplasia
 osteonecrosis,
 Trauma
 Previous surgery such as HTO and
 previous total knee replacement

14. Contained or cavitary defects
have an intact rim of cortical bone
surrounding the deficient area

15.  Noncontained or segmental defects
are more peripheral and
lack a bony cortical rim

16. Rand classification
 Type I: focal metaphyseal defect, intact cortical rim
 Type II: extensive metaphyseal defect, intact cortical rim
 Type III: combined metaphyseal and cortical defect

17. Management
 Small defects (<5 mm) typically are filled with
cement.

18. Contained type

19. structural
bone grafts
(bone block from
distal femoral
resection)
screws within
cement
metal wedges in
prosthesis
Non Contained type

20. Some studies..
 No progression of tibial
radiolucencies was seen
over 7 years in 25 knees
in which screw
augmented cement
(polymethyl methacrylate)
wasused to fill large
tibial defects

21.  145 TKAs (20 all-polyethylene tibial components and
125 metal-backed trays) with medial tibial defects
treated with screws andcement,
 medial collapse occurred in two
 lateral collapse in one all in metal-backed tibial
components;
 no revisions were required.

22. WINDSOR,
INSALL, AND
SCULCO technique

23. Convert the concave, irregular defect to
a flat one by minimal bone removal with
a saw

24.  Attach bone
removed from the
distal femur or
proximal tibia to
the flattened
defect, and
secure it with
threaded
Steinmann pins or
screws

25. Carefully recut the upper tibial surface to
create a flat upper tibial surface.

28.  During cementing, premix a small batch of
cement and use it to seal the junction of
the bone graft with the tibia to prevent
extrusion of cement into this interface
during final component cement fixation.

29. If the defect cannot be corrected
level the irregular bone surfaces with a burr
to allow maximal graft-host bone
apposition

30.  Restoration of neutral
alignment is essential
because this has been
shown to affect bone
graft survival and
prosthesis loosening.
 Intramedullary stems
on the femoral and
tibial components
commonly are used to
protect peripheral
bone grafts from stress

31. Brand et al.
first use of modular metal wedges
attached to the tibial tray to compensate for
tibial bone deficiencies

32.  Most modern total knee systems employ
modular wedges and blocks that can be
attached to femoral and tibial components to
compensate for multiple bone deficiencies.
 a surgeon can literally build a custom
prosthesis in the operating room for a given
defect or combination of defects.