Types
Peri-operative
- incurred during operation
Post operative
- related to osteolysis / trauma / infection
Follow up
1994 National Institutes of Health Consensus on THR
Regular radiographic follow-up to avoid massive osteolysis & fracture
Incidence
Primary
0.6% cemented
0.4% uncemented
Revision
2.5% cemented revision
1.5% uncemented revision
Aetiology
1. Bone damage at insertion
- eccentric reaming
- perforation
- fracture
2. Osteolysis
3. Trauma
4. Infection
5. Osteoporosis
Vancouver Classification
Type A (4%)
Avulsion GT or LT
A1 Stem well fixed
A2 Stem loose
Type B (87%)
Fracture near stem tip or around stem
B1 Stem well fixed (20%)
B2 Stem loose (44%)
B3 Stem loose with marked osteolysis (36%)
Type C (10%)
Fracture distal to tip
Management
Most important is whether prosthesis is stable
- if loose requires revision
Type A
Avulsion GT or LT
Management
GT
- undisplaced - no treatment required
- ORIF GT if displaced > 2.5 cm / disruption to abductors
LT
- cerclage LT if large and supportive
Type B1
Fracture around stem, likely well fixed
Options
1. ORIF with cable plate + proximal unicortical locking screws +/- Cortical strut graft
Cable plate alone
- 90% union
Locking Cable plate + single strut graft
- 98% union
- distal bicortical screws
- proximal unicortical screws supplemented with cables
2. Long stem revision
Cemented
Uncemented
Type B2
Fracture around stem, femoral component loose
Options
Long stem revision
- distal fit (cemented / uncemented)
- must bypass distal extent of fracture by at least 2 cortical diameters
May in addition use
- cable plate + unicortical locking screws
- 1 x strut allograft
- autogenous BG + BMP to fracture site
Type B3
Fracture around stem with marked osteolysis
Options
Young patient
- segmental allograft / prosthesis composite
Elderly
- tumour type proximal femoral replacement
Type C
Fracture distal to tip of stem
Options
1. ORIF Cable Plate
- can use MIPO
- overlap femoral stem to avoid stress riser
2. ORIF Cable Plate + cortical strut graft
2. Strut allograft alone
- use 2 x 1/2 femurs fresh frozen
- span fracture 10cm above & below
- 4 wires above & below
- preserve blood supply to linea aspera
- autogenous graft to fracture site