What is the best course of treatment for a patient with osteoarthritis (OA) of the hip secondary to a malunited acetabulum fracture?

Treatment of Hip Osteoarthritis Secondary to Malunited Acetabular Fracture

Total hip arthroplasty (THA) is the definitive treatment for symptomatic hip osteoarthritis secondary to malunited acetabular fracture when conservative management has failed. 1, 2

Initial Conservative Management

Before proceeding to surgery, patients should complete trials of appropriate nonoperative therapies, though the threshold for surgical intervention may be lower in post-traumatic cases 1:

Non-Pharmacological Interventions

• Land-based cardiovascular and resistance exercise supervised by a physical therapist, combined with manual therapy 2
• Aquatic exercise for patients who cannot tolerate land-based activities 2
• Weight reduction if the patient is overweight or obese 1, 2
• Walking aids (cane or walker) to reduce joint loading 1, 2
• Education and self-management programs to improve disease understanding 2

Pharmacological Management

• Acetaminophen (up to 4g/day) as first-line oral analgesic for mild-moderate pain 1, 2
• NSAIDs at the lowest effective dose if acetaminophen provides inadequate relief, with gastroprotection for high-risk patients 1, 2
• Opioid analgesics (such as tramadol) when NSAIDs are contraindicated or ineffective 1, 2
• Ultrasound or x-ray guided intra-articular corticosteroid injections for acute flares unresponsive to oral medications 1, 2

Critical caveat: Glucosamine, chondroitin, and intra-articular hyaluronic acid are NOT recommended for hip OA 1, 2

Surgical Decision-Making Algorithm

When to Proceed to Surgery

Proceed to THA without arbitrary delay when patients meet ALL of the following criteria 1:

1. Radiographic evidence of moderate-to-severe OA (Tonnis grade 2-3 or equivalent) 1
2. Moderate-to-severe pain or functional disability despite conservative treatment 1
3. Failed ≥1 appropriate trials of nonoperative therapy 1
4. Shared decision-making confirming patient readiness 1

Do not mandate a 3-month waiting period as an arbitrary "cool-down" before proceeding to THA 1

Special Considerations for Post-Traumatic Cases

Post-traumatic hip OA following malunited acetabular fracture presents unique surgical challenges 3:

• Meticulous preoperative planning with plain radiographs AND CT scans to delineate fracture pattern and bone stock 3
• Previous hardware removal only if it interferes with cup implantation or is infected 3
• Goal is to restore columns for acetabular component implantation rather than anatomic fracture reduction 3
• Uncemented porous metal acetabular components with multiple screw options are preferred for most cases 3, 4
• Ceramic-on-ceramic bearings may provide superior long-term outcomes (88.4% survival at 10 years) with lower osteolysis and infection rates 4

Alternative Surgical Options

Joint-preserving procedures (osteotomy, surgical dislocation) should be considered ONLY in 1:

• Young adults (typically <40 years) with symptomatic hip OA 1
• Presence of dysplasia or varus/valgus deformity amenable to correction 1
• Earlier disease stages where joint replacement is not yet justified 1

However, in the context of malunited acetabular fracture with established OA, these options are rarely appropriate as the anatomic distortion typically precludes effective joint preservation 3

Preoperative Risk Optimization

Before proceeding to THA, counsel patients on modifiable risk factors 1:

• Glycemic control in diabetic patients to reduce infection risk 1
• Nicotine cessation to improve wound healing 1
• Weight optimization though surgery should not be indefinitely delayed for this alone 1

Recognize that not all patients have resources to modify these factors, and surgery should not be withheld indefinitely 1

Expected Outcomes

Post-traumatic THA following acetabular fracture has lower success rates than primary THA 3, 5:

• Revision rates are higher in post-traumatic cases 3
• Harris Hip Score improvement from baseline ranges 36-46% 1
• Pain-free outcomes occur in 43-84% of patients at long-term follow-up 1
• Ceramic-on-ceramic bearings may achieve 88.4% survival at 10 years with lower complication rates 4

Critical Pitfalls to Avoid

• Do not delay surgery with prolonged conservative management once clear surgical indications are met, as this does not improve outcomes 1
• Do not attempt joint preservation in established post-traumatic OA with significant anatomic distortion 3
• Do not use intra-articular hyaluronic acid as it is not recommended for hip OA 2
• Do not proceed without CT imaging in post-traumatic cases, as plain radiographs are insufficient for surgical planning 3
• Ensure availability of revision implants and bone graft as backup, given the complexity of post-traumatic anatomy 3