Indication
Total hip arthroplasty is considered when hip disease causes substantial pain and functional limitation despite appropriate non-operative treatment, and when the expected benefit justifies the surgical risk.
Total hip arthroplasty is indicated for substantial pain and functional limitation from end-stage hip disease when non-operative treatment no longer provides acceptable control.
The decision is based on symptoms and function, supported by imaging, rather than radiographs alone.
Goals
- relieve pain
- improve function
- restore a useful range of motion
- reconstruct centre of rotation
- restore appropriate offset
- achieve acceptable leg length
- obtain stable component fixation and orientation
Preoperative planning
Review:
- diagnosis and deformity
- bone quality
- leg length
- femoral and acetabular anatomy
- previous scars or operations
- thromboembolic and infection risk
- patient expectations
Assess:
- diagnosis and deformity
- previous surgery
- infection risk
- bone quality
- leg length
- offset
- acetabular morphology
- femoral anatomy
- comorbidity
- thromboembolic risk
- patient expectations
Templating estimates component size and reconstruction but is not a substitute for intraoperative judgement.
Consent
Discuss benefits, alternatives and material risks relevant to the individual patient.
Important risks include:
- infection
- dislocation
- venous thromboembolism
- fracture
- nerve injury
- leg-length discrepancy
- persistent pain
- loosening/wear and later revision
- anaesthetic and medical complications
Consent is a shared decision, not a recital of percentages.
Surgical approaches
Common approaches include:
- posterior
- direct lateral
- anterolateral
- direct anterior
The best approach is one that allows accurate reconstruction with a low complication rate in the surgeon's hands. Each approach has characteristic risks to soft tissues and nerves.
Component position
Orientation should be individualised to:
- spinopelvic mechanics
- implant design
- surgical approach
- soft-tissue tension
- patient's functional range
A fixed universal “safe zone” should not be treated as a guarantee against dislocation.
Acetabular reconstruction
Goals include:
- stable fixation
- appropriate centre of rotation
- adequate bone coverage
- safe orientation
- restoration of hip mechanics
Excessive medialisation, lateralisation or abnormal inclination/anteversion can affect stability, wear and impingement.
Femoral reconstruction
Aim to restore:
- length
- offset
- version
- stable fixation
- abductor tension
Increasing offset can improve abductor mechanics and stability but excessive offset may increase soft-tissue tension and load.
Approaches
Common approaches include:
- posterior
- direct lateral
- anterior
Each has advantages and specific risks. Outcome depends heavily on execution, soft-tissue management and component position rather than approach name alone.
Fixation
Cemented and uncemented fixation can both perform well in appropriately selected patients.
Cemented fixation provides immediate mechanical fixation through a cement mantle. Uncemented components rely on initial press-fit stability followed by biological fixation.
Choice depends on:
- age
- bone quality
- femoral geometry
- implant design
- surgeon experience
Stability
Dislocation risk is influenced by:
- component position
- head size
- soft-tissue tension
- abductor function
- impingement
- spinal/pelvic mobility
- approach and repair
Complications
Discuss:
- infection
- dislocation
- fracture
- nerve injury
- leg-length discrepancy
- VTE
- heterotopic ossification
- loosening/wear
- perioperative medical complications
FRCS synthesis
THA is a biomechanical reconstruction, not just replacement of surfaces. Explain how you restore centre of rotation, offset, length and soft-tissue balance while obtaining durable fixation.