Chapter 53 - Periprosthetic Fractures Associated with Total Hip and Knee Arthroplasty

Question 1

intraoperative risk factors for acetabular fracture

Answer 1

• press fit cups
• underreaming by >=2mm (most arthroplasty surgeons do 1mm)
• eliptical components
• osteoprosis, pagets

Question 2

Type I intraoperative acetabular fractures

Answer 2

intraoperative fracture 2/2 acetabular impaction
A. non-displaced, component stable
- leave cup in place, augment with lots of screws
- protected weightbearing

B. displaced
- remove cup, use cancellous screws to fix the fracture, use a buttress plate if posterior cup is involved
- re-ream line to ikne
- multihole revision cup for lots of screws
- protected weightbearing

C. not recognized intraop

Question 3

Type II intraoperative acetabular fractures

Answer 3

intraoperative fracture secondary to acetabular implant removal
- large revision acetabular implant with multiple screws

Question 4

Type III peri-implant acetabular fracture

Answer 4

traumatic fracture
IIIA - component stable
- leave it in place and protect WB for 8-12 wks

IIIB - component unstable
- revision to porous revision acetabular implant with multiple screws

Question 5

Type IV peri-implant acetabular fracture

Answer 5

spontaneous fracture
IVA - <50% acetabular bone stock loss
- large revision acetabular with multiple screws, bone graft as needed

IVB - >50% acetabular bone stock loss
- Bulk allograft or metal augment
- cage or cup cage if host bone is insufficient to allow bone ingrowth

Question 6

Type V peri-implant acetabular fracture

Answer 6

pelvic discontinuity
VA - bone loss <50%
- posterior column fixed with pelvic plate
-bone graft at fracture site
- revision cup, multiple screws, protected WB

VB - bone loss >50%
- bulk allograft or metal augments
- fix PC with pelvic plate
*** Cemented acetabular cup, cup cage, or custom triflange

VC- associated with previous radiation
- same as VB - use cement

Question 7

At wht time point can you use bone scan for identification of peri-implant fx

Answer 7

After 1 year post op

Question 8

How do you treat a stable fem shaft fracture (minimally displaced longitudinal split) that was not seen intraop but is present on post op XR?

Answer 8

protected WB until radiographic union

Question 9

Vancouver A fracture

Answer 9

A = around trochanter
AG - greater
- treat symptomatically wit protected WB, limited active adbuction and passive adduction
- only surgery if >2.5cm displacement or symptomatic non-union

AL - lesser
- only operate if a huge chunk of the medial cortex is attached

Question 10

vancouver B fracture

Answer 10

at or JUST distal to the level of the stem
B1 - well fixed implant
- ORIF (must fix two planes - anterior and lateral) - cables, strut grafts, locking plates, whatevs
B2 - stem is loose, but good bone stock
- long stem revision
B3 - stem is loose, bad bone stock
- long stem revision, APC (for young person to save bone stock for future revisions), megaprothesis/PFR if elderly

Question 11

Vancouver C fracture

Answer 11

well distal to the stem
- ORIF with distal femur locking plate, blade plate, condylar screw plate etc
- overlap plate and stem to prevent stress riser

Question 12

risk fractures for per-implant TKA fractures

Answer 12

• rheumatoid
• nerologic disorders
• chronic steroids
• osteopenia/osteoporosis
• osteolysis with bone loss
• +/- anterior femoral notching

Question 13

types of tibial peri-implant TKA fractures

Answer 13

I - at the level of the plateau
- IA: well fixed
- IB: loose
- IC: intraop

II - adjacent to the tibial stem
- IA: well fixed
- IB: component loose
- IC: intraop

III - shaft fracture distal to the implant
- IA: well fixed
- IB: component loose
- IC: intraop

IV - tubercle fracture
- IA: well fixed
- IB: component loose
- IC: intraop