The unstable total hip arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Arthroplasty Research

Background:

• Hip dislocation is a frequent complication following total hip arthroplasty (THA), leading to patient suffering, increased risks, and healthcare costs.
• Dislocation rates vary significantly based on the underlying cause, being substantially higher in cases of avascular necrosis, congenital dislocation, fracture, nonunion, malunion, failed hip arthroplasty, and prosthetic instability compared to degenerative arthritis.

Purpose of the Study:

• To analyze the causes and contributing factors of hip instability after total hip arthroplasty (THA).
• To review revision strategies for unstable total hip arthroplasty (THA).

Main Methods:

• Review of literature on total hip arthroplasty (THA) instability.
• Classification of instability causes into local (with or without radiographic findings) and non-local (patient-related factors).

Main Results:

• Instability in THA can stem from local hip issues or non-local factors like patient compliance or neurological disorders.
• Specific conditions like avascular necrosis, congenital dislocation, and prior hip surgeries significantly increase dislocation risk.

Conclusions:

• Effective revision of unstable total hip arthroplasty (THA) requires addressing the root cause of instability.
• Revision strategies often involve correcting the etiology and may include upsizing the femoral head and liner to enhance stability.