Intra-operative Fracture

THR Acetabular Fracture

 

Incidence

 

Increased incidence with press-fit component

- especially if under ream

 

Prevention

 

Don't under-ream >1mm

 

In osteopenic bone 

- line to line reaming

- i.e. ream to outer diameter of cup

 

This also avoids leaving gaps at floor 

- very common if under-ream by 2mm

 

Management Intra-operatively

 

Intra-operative undisplaced fracture + Stable cup

- 2-4 screws through cup

- TWB 2-3 months

 

Intraoperative displaced fracture

- remove cup

- plate posterior column if factured

- screw fixation anterior column

- additional screws in cup

- +/- antiprotrusio ring                    

- TWB 2-3 months

 

THR Fractured AcetabulumTHR Fractured Acetabulum 2THR Fractured Acetabulum 3

 

Diagnosis Post operatively

 

Can be difficult to diagnose & image

- if unexplained groin pain post-op & press-fit cup 

- look for fracture with multiple oblique views etc

- CT

- may see callous formation

 

THR Intraoperative Acetabular Fracture

 

Post-operative early

 

1. Non or minimally displaced

- recognised immediate post-op

- TWB 3 months

 

2. Displaced fracture unstable

- ORIF & revise cup

 

Post-operative late

 

Peterson & Lewallen JBJS Aug 1996

 

Type 1

- cup clinically & radiologically stable

- no treatment

 

Type 2

- cup unstable

- revise as above

 

THR Femoral Fracture

 

THR Femoral Intraoperative FractureUncement Femur Intraoperative Fracture

 

Incidence

 

Increased incidence with press-fit components

- act like splitting wedge

 

Fracture may occur during

 

1. Dislocation

2. Reaming or broaching

3. Impaction of component

4. R/O cement or old components 

 

Prevention

 

During dislocation

 

Beware in elderly, osteoporotic patient and in revision

- adequate exposure

- only 1 person manipulate femur

 

If difficult dislocation

- complete ST release

- removal of acetabular osteophytes

- ankylosed joint or protrusio, division of neck in situ & piecemeal removal of femoral head

 

During femoral preparation

 

Pre-op templating of component size

- use of reamers before broaching to remove endosteal bone

- gentle broaching with pause if failing to advance

- sufficient broaching for easy prosthesis insertion

 

Avoid creation of stress risers i.e. cracks, defects, windows

 

If cracks or defects created

- bypass with implant by 2-3 cortical diameters distally

- minimise cement extravasation as prevents healing of defect

- use cerclage wires to prevent propogation of fracture

 

During component insertion

- gentle impaction with pause if failing to advance

- uncemented components often 1 - 2 mm proud of equivalent sized broach

 

Management

 

Vertical split not beyond LT

- cerclage wire

 

Vertical split beyond LT 

- cerclage wires

- longer stem

 

Perforation of shaft

- bypass defect

- fixate with plate