What is the recommended post‑reduction management for a patient with a traumatic hip dislocation?

Post Hip Dislocation Management

After successful closed reduction of a traumatic hip dislocation, obtain post-reduction radiographs to confirm reduction and identify associated fractures or loose bodies, followed by CT hip without IV contrast to evaluate joint congruence, intraarticular fragments, and acetabular fractures—particularly for posterior wall fractures or failed closed reductions. 1

Immediate Post-Reduction Imaging

Plain Radiographs First

• Post-reduction X-rays are mandatory to confirm successful reduction and detect obvious fractures or loose bodies
• X-rays have 100% sensitivity for identifying pathology requiring surgery 2
• X-rays detect 67% of all pathology later found on CT, but capture all surgically relevant findings 2

CT Hip Without IV Contrast - When to Obtain

Strongly indicated for:

• Radiographically visible posterior acetabular wall fractures - CT characterizes fracture extent to determine surgical necessity and prevent recurrent dislocation 1
• Failed closed reduction - CT identifies entrapped fracture fragments within the joint 1
• Any concern for joint incongruence or intraarticular fragments on post-reduction radiographs 1

Important caveat: CT sensitivity for intraarticular fragments is only 87.3%, with 43.3% of patients having fragments at arthroscopy despite negative CT 1. Additionally, 78% of patients with negative radiographs AND CT had intraarticular fragments found arthroscopically 1. This means CT does not exclude small intraarticular pathology, but it captures what matters for immediate surgical decision-making.

May be omitted if:

• Post-reduction X-rays show perfect reduction with no fractures or loose bodies
• No pre-reduction fractures were identified
• Patient had pre-reduction CT showing no fractures (no new findings on post-reduction CT in this scenario) 2

Imaging NOT Recommended

• Bone scan - no evidence of utility 1
• CT with IV contrast - no added benefit 1
• MRI without and with contrast - not indicated acutely 1

Post-Reduction Activity Protocol

Begin early mobilization within 7-10 days after reduction with partial weight-bearing, progressing to full weight-bearing at 3 months. 3

Evidence-Based Mobilization Approach

• Avoid prolonged skeletal traction - a 7.6-year follow-up study showed no benefit of 2 weeks traction versus early mobilization at 9 days 3
• Both approaches had identical rates of avascular necrosis (0%), post-traumatic arthritis, and heterotopic ossification 3
• Early mobilization resulted in earlier return to work and greater patient comfort 3
• No early complications occurred with the mobilization protocol 3

Practical Protocol

• Days 1-9: Protected mobilization, pain control, neurovascular monitoring
• Weeks 2-12: Partial weight-bearing with assistive devices
• Month 3 onward: Progress to full weight-bearing as tolerated

Critical caveat: This applies to simple dislocations without significant acetabular or femoral head fractures. Adjust weight-bearing restrictions based on associated fracture patterns requiring surgical fixation.

Monitoring for Complications

Time-Sensitive Concerns

• Reduction timing matters - although the evidence shows outcomes are "largely driven by time to reduction" 4, the specific 6-hour window traditionally cited is not strongly supported in recent literature
• Sciatic nerve injury occurs in 27.5% of hip dislocations, particularly with posterior acetabular rim or Pipkin Type-IV fractures 5
• Document neurovascular status immediately post-reduction and serially

Long-Term Surveillance

• Avascular necrosis risk: 13% at mean 6-year follow-up 5
• Post-traumatic osteoarthritis: 31.9% at mean 6-year follow-up 5
• THA requirement: 19% of patients ultimately need arthroplasty 5
• Highest risk patients: Those with posterior acetabular rim fractures or Pipkin Type-IV fractures 5

Associated Injuries to Screen For

• Ipsilateral knee injuries in 29% of patients, particularly PCL tears (41.2% of knee injuries) 6, 5
• Hip dislocation increases knee injury risk 7-fold (OR 7.25) 6
• Obtain knee MRI if any clinical suspicion - tibial plateau fractures may not be visible on plain films 6
• Upper extremity injuries in 21.7% 6

Functional Outcomes to Counsel Patients About

Set realistic expectations:

• Only 33.3% return to pre-injury sports level 5
• 24.6% do not return to work 5
• 27.5% report sexual dysfunction 5
• Outcomes significantly worse with osteonecrosis, post-traumatic OA, or residual sciatic nerve injury 5

Recurrent dislocation is rare (2%) but suggests ligamentous damage or residual acetabular pathology requiring individualized surgical management 7.