Dislocation of a Native Hip

• Uncommon – High-Energy injury
• All patients presenting with a suspected native hip dislocation following trauma (including falls from standing) must have a primary survey done to assess for other injuries.
• Early Senior input (if not trauma team) and Resus
• Neurovascular status of the affected limb must be assessed and documented. 

Dislocation of Prosthetic Hip

• Relatively common and frequently low energy
• All patients should be assessed with low threshold to treat as trauma
  • Remember the biggest cause of ISS >15 Major Trauma in UK is older patients falling from standing height
• Neurovascular status of the affected limb must be assessed and documented. 
• If there is neurovascular compromise then move to Resus and inform ED senior 

• *Consider reduction in ED if patient appropriate to sedate, ED and orthopaedic staff available and department able to accommodate. 
• ** Facilitated by orthopaedics, taking into account mobility review, physio input, pain management, leg brace and appropriate follow-up arranged etc

Hip Dislocation Presentation (Detail)

Common Mechanisms for Dislocations 

Native hip dislocations are most often associated with high energy impact such as a road traffic collision – don’t forget to assess for other injuries and consider whether further imaging is required. 

Prosthetic hip dislocations are most common in the first 3 months after surgery. Movements such as bending forward to tie shoelaces, sitting in low chairs or sitting with legs crossed can prompt dislocation. 

Presenting Symptoms 

Patients with hip dislocations present with pain, inability to weight bear and may have a shortened limb on the affected side.  

Risk Factors for Dislocations

Patients with the following are at an increased risk of prosthetic hip dislocations

• History of prior hip surgery 
• Extremes of BMI 
• Parkinsons and other neuromuscular conditions 
• Drug and alcohol misuse 
• Poor compliance with post operative hip precautions 
• Previous dislocations 
• Spinal fusion surgery 

Native hip dislocations 

Native hip dislocations need to reduced in a timely manner to reduce the risk of avascular necrosis to the femoral head and long term nerve damage. In order to successfully reduce a dislocated native hip the patient needs to be adequately sedated with muscles relaxed – this is often deeper than we can achieve with safe procedural sedation in ED. 

• The patient should be kept nil by mouth 
• Prescribe adequate analgesia and intravenous fluids 
• Ensure critical medications are not omitted 
• Refer to orthopaedics for reduction in theatre. 

1^st Time Prosthetic Hip Dislocations 

First time prosthetic hip dislocations can occur for many reasons including issues relating to the placement and size of the implant used in the initial surgery. Reduction attempts without adequate sedation can increase the risk of damage to the implant. Reductions of first time prosthetic hip dislocations are most likely to be successful when performed in theatre using a c arm. This also allows the orthopaedic team to fully assess the range of motion and stability of the joint. First time prosthetic dislocations should not be reduced under sedation in ED. 

• The patient should be kept nil by mouth 
• Prescribe adequate analgesia and intravenous fluids 
• Ensure critical medications are not omitted 
• Refer to orthopaedics for reduction in theatre. 

Is it safe to sedate in ED? 

EMBEDS page on adult procedural sedation is available here https://www.embeds.co.uk/2024/06/04/adult-sedation/

The decision whether it is safe to sedate the patient in the emergency department environment is multifactorial and the seditionist, emergency physician in charge and nurse in charge should consider the following:- 

Patient factors 

• Is the patient suitably fasted? 2 hours for clear fluid, 6 hours for solids. 
• Does the patient have a potentially difficult airway? 
• Is the patient clinically stable?
• ASA score and co-morbidities
• Does the patient have a history of adverse reactions to anaesthetic or specific contraindications to the planned sedative agents? 

Personnel factors 

• Is there a clinician trained to sedate available?
• Is there a nurse available to be present during sedation?
• Are there members of the orthopaedic team available to perform the reduction? 

Departmental factors 

• Is there capacity for the procedure to be performed in resus? 
• Can the patient be stepped down from resus to a monitored cubicle promptly after reduction?
• What is the wait to be seen by clinician? 
• Has the procedure been agreed with EPIC and NIC?

References

1. https://www.embeds.co.uk/2024/06/04/adult-sedation/
2. https://rcem.ac.uk/wp-content/uploads/2022/08/RCEM_BPC_Procedural_Sedation_Final_Aug_22.pdf
3. https://www.rcemlearning.co.uk/reference/adult-procedural-sedation/#1568021119806-903d59f3-327a
4. https://www.nhs.uk/tests-and-treatments/hip-replacement/recovering-from-a-hip-replacement/#:~:text=Following%20the%20exercises%20early%20on,touch%20your%20feet%20or%20ankles
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC6162140/
6. https://www.orthobullets.com/recon/5012/tha-dislocation