Possible Indications for Primary THR for Fracture
- High demand patient
- Pre-existing symptomatic arthritis
- Paget’s disease
- Rheumatoid arthritis
Problems with Femoral Neck Non-unions or Failed Fixation
- Avascular Necrosis (AVN)
- Hypervascular tissues and more blood loss
- Non-Union:
- Free trochanter, etc.
- No calcar in IT fractures:
- Deformity, shortening, and contracture
- Scarring of nerves
- Poor Bone Quality
- Retained Hardware
AVN
- Hypervascular tissues and more blood loss
Shortening
- Soft tissue contracture:
- Multiple releases required to expose, maintain stability, and provide range of motion
Trochanteric Non-unions
- May need a calcar replacing stem ± claw plate
Existing Metalware
- Remove if possible
- Consider strut grafts to support weak bone
- Plug holes to prevent cement extrusion
- Uncemented prostheses if possible but not strictly necessary
- Bypass screw holes by two bone diameters to avoid stress riser
Acetabular Fractures
- Primary THR may be indicated if:
- Co-existing neck fracture
- Pre-existing arthritis
- High demand with irreconstructable fracture
Problems with Old Acetabular Fractures
- Bone Loss:
- Especially posterior > cup retroversion
- Medialise cup
- Use structural graft to support uncovered posterior cup
- Exposure difficult due to scarring
- Deformity due to malunion
- Protrusio
- Displacement of NV structures
- Retention of hardware if previous acetabular ORIF:
- Remove if possible or ream and remove as becomes apparent
- Leave what does not interfere with cup placement
Considerations in Proximal Femoral Deformity
- Soft tissue problems
- Difficulty accessing the canal due to sclerotic bone:
- Use high speed burrs, drills or open retrograde via subtrochanteric osteotomy
- Calcar replacement stems if necessary
- DDH stems if very small or deformed canal
- Osteotomy, realignment then bypass with long uncemented stem
- Distal deformities can be ignored but may lead to early implant failure