Indications for Hip Replacement
Hip replacement is indicated for patients with moderate-to-severe symptomatic osteoarthritis or advanced osteonecrosis with secondary arthritis who have failed nonoperative treatment and experience significant pain and functional limitations that impair quality of life. 1
Primary Clinical Criteria
The decision to proceed with total hip arthroplasty (THA) should be based on three key domains that directly impact patient outcomes:
1. Pain Severity
- Rest pain and pain with activity are the most critical indicators 2
- Pain must be severe enough to significantly limit daily activities and quality of life
- The pain should be refractory to conservative management
2. Functional Impairment
- Significant limitations in activities of daily living
- Inability to perform routine tasks due to hip pathology
- Reduced mobility affecting independence 1, 3
3. Failed Conservative Treatment
- Patients must have already unsuccessfully tried nonoperative treatment before being indicated for THA 1
- This includes physical therapy, NSAIDs, weight management, assistive devices, and intra-articular injections
- Important caveat: Delaying surgery for additional nonoperative treatments in patients already meeting criteria is inappropriate and leads to further disability 1
Specific Disease Indications
The most common pathologies warranting hip replacement include:
- Primary osteoarthritis (60% of cases in younger patients) 4
- Osteonecrosis of the femoral head (24% of cases) 4, 5
- Secondary osteoarthritis from developmental dysplasia, prior trauma, or childhood hip disorders 5, 6
- Rheumatoid arthritis 5
- Posttraumatic arthritis 4
- Femoral neck fractures in active patients 5
Critical Decision-Making Framework
The 2023 ACR/AAHKS guidelines emphasize that THA is the only definitive therapy for moderate-to-severe symptomatic hip OA 1. The decision should follow this algorithm:
- Confirm radiographic evidence of moderate-to-severe disease (though radiographic severity alone is NOT sufficient) 1
- Document failed conservative treatment (not just incomplete attempts)
- Assess symptom severity using the pain and functional criteria above
- Engage in shared decision-making with the patient regarding their goals, risk tolerance, and expectations 1
Common Pitfalls to Avoid
Do NOT impose rigid cutoffs for:
- BMI thresholds (e.g., BMI <40)
- HbA1c levels (e.g., HbA1c <8%)
- Complete smoking cessation
While these factors increase perioperative risk and should be optimized when possible, inflexible cutoffs limit access to care and increase disparities, particularly for racial and ethnic minorities 1. The 2023 guidelines explicitly reject universal thresholds because the harm from denying surgery to many patients outweighs the benefit of preventing complications in a small number 1.
The Optimization Approach
Instead of mandatory cutoffs, counsel patients about increased risks and encourage preoperative optimization:
- Weight loss for elevated BMI
- Glycemic control for diabetes (HbA1c ideally <7.3%) 7
- Smoking cessation
- Narcotic weaning 7
However, failure to achieve these targets should not automatically disqualify patients from surgery 1. Each case requires individualized risk-benefit assessment through shared decision-making.
Timing Considerations
Do not delay surgery once criteria are met 1. Studies show that only 9% of patients deemed appropriate for THA receive timely surgery (within 2 years), while 91% experience inappropriate delays 1. These delays result in:
- Increased pain and disability
- Worsened physical function
- Higher risk of chronic disease
- Decreased quality of life 1
Patients overwhelmingly prefer to proceed directly with surgery rather than undergo mandatory additional conservative treatments (93% in one survey) 1.
Expected Outcomes
When appropriately indicated, THA provides:
- 90-95% patient satisfaction 3
- 95% implant survival at 5 years and 76% at 25 years in Denmark 3
- ~94% implant survival at 10 years across all indication groups, even in young patients aged 15-45 4
- Significant improvements in pain, function, and quality of life 1, 3
The key is not to delay surgery in appropriate candidates, as THA remains one of the most successful surgical interventions in modern medicine 8.