Leg Pain Station

Presenting Complaint:

“I had a fracture of my shin while working yesterday morning and it was operated on in the afternoon. I thought everything would be fine but I’m in so much pain and it doesn’t feel or look right. I can’t even move my leg without feeling excruciating pain.”

History of presenting complaint 

• Site – shin
• Onset – yesterday afternoon
• Character – feels tight like it’s going to burst
• Radiation – nil
• Associated symptoms – swollen limb
• Timing – constant, sudden onset
• Exacerbating and relieving factors – any movement of the leg
• Severity – 10/10

Systems review

• Infective – No fevers, no spreading erythema, no discharge from wound, no dehiscence, no immunocompromise
• VTE – No shortness of breath, no haemoptysis, no palpitations, no syncope, no active cancer, no previous VTE history
• Trauma – no falls or further injuries following surgery

Past Medical History

• High blood pressure that’s under control with medication.
• No active cancer, no previous VTE
• No diabetes, no immunocompromise

Family History

• Family history of CVD, father died from MI at age 78

Social history

• Works in construction
• Smokes 1 pack daily since he was 20
• Alcohol: drinks socially 1-2 times a week, about 3-4 beers per time

ICE:

• Idea – no idea what’s going on (scared)
• Concern – maybe something went wrong with the surgery afraid for his leg
• Expectation – find out what is causing the problem and resolve it straight away

This should be presented in a systematic way (general examination, hands, face, inspect, palpate, auscultate etc.)

• Inspection – 
  • patient in distress (sweating)
  • severe pain
  • inability to move
  • affected limb is erythematous
  • swollen and in pain
  • check site of incision for any abnormalities (none found)
    • Tissue – granulation, colour 
    • Exudate – type (Serous, sanguineous, serosanguineous, or purulent), volume and consistency 
    • Periwound condition – inspect wound margins 4-5cm around wound for any changes in surrounding tissues (e.g. lymphedema, loss of sensation, arteriovenous insufficiency).
    • Evaluate – warmth, pain, purulence, odor
  • Inspection of hands, arms, face, torso are unremarkable.

• Observations
  
  • BP 168/92
  • HR 113
  • RR 25
  • T 36.7 °C

• Examination of limb 
  • Neurovascular assessment:
    • Pain – palpation causes severe pain on affected limb
    • Temperature – Warmer than unaffected limb 
    • Paresthesia – slight pins and needles in affected foot
    • Paralysis – no paralysis
    • Pulse – dorsalis pedis artery and anterior/ posterior tibial arteries palpable
    • Pallor – unremarkable

• Lower limb musculoskeletal examination including passive, active movements followed by testing for sensation and power
  • Passive and active movements severely limited by pain on flexion and extension. 
  • Unaffected limb - can complete all lower limb examination requirements normally including sensation and power. When comparing the two start with UNAFFECTED limb then AFFECTED limb.

NOTE: "Compartment syndrome manifests differently based on one's anatomy and the trauma inflicted. To determine the extent of the damage it is imperative to explore every one of the 5 P's of compartment syndrome, with paralysis being the one. If you do not assess paralysis and paresthesia in union, you subsequently do not have a complete neurological understanding of the limb during the neurovascular assessment, because in their moments of severe pain, the patient may interpret paresthesia as a form a sensation during a neurovascular examination. Paralysis of a limb can occur within 6 hours of the onset of compartment syndrome. Therefore, given that the patient in the scenario also had a very traumatic injury, and they present with a vague history with respect to when the onset of pain began, paralysis should still be assessed even at a minimal extent, since the ultimate window of opportunity to save the limb from irreversible muscle damage is 8 hours, and 6 hours for paralysis." 

• Systems review - unremarkable 
• Key examination findings should be given, both important positives and negative
• Positive examination findings:
  • Swelling and discolouration of limb
  • Pain ON PASSIVE and ACTIVE MOVEMENT that is out of proportion to clinical situation.
  • Slight paresthesia
• Negative examination findings:
  • No paralysis, patient can still move limb with severe pain.
  • Peripheral pulses are still palpable.

Question 1: “Please present your findings.”

I was asked to review a 55-year-old gentleman presenting one day post-op for a complete tibial fracture. He was in distress with severe pain in his lower limb that was out of proportion with the presenting complaint on passive and active movement, swelling and discolouration and slight paraesthesia. He did not have paralysis and peripheral pulses were palpable. 

Question 2: “What investigations would carry out?”

State that they suspect that compartment syndrome is the cause of the patients PC and that it is INITIALLY confirmed via their clinical examination.

Bedside investigations:

• • Urinalysis - myoglobinuria indicates onset of muscle ischaemia or rhabdomyolysis 

Laboratory investigations:

• Bloods – FBC, WBC, U&E’s, LFT’s  and infective markers (these would be raised post-surgery), creatine kinase may be slightly elevated due to the onset of muscle cell lysis. 

Imaging:

• X-ray - rule-out iatrogenic caused fracture from operation or problem with internal fixation device.

• Special Tests:

Intercompartmental pressure measurement (ICP) – used to measure pressure in different muscle compartments of the affected limb. Must be >30mmHg

Question 3: “Interpret the following x-ray.”

Must be systematic in approach outwards to inwards. Mention no dark areas around the knee or leg indicating any potential haematoma or swelling. View cortical outline of bone and say that it is all intact with the exemption of the fractured areas from the patient accident. Mention that there is no displacement of the intramedullary nails. 

X-ray from1: Dr Adita Shetty, Intramedullary nail fixation for tibial and fibular fracture, Radiopedia, Creative Commons Licence: Creative Commons Attribution-Non-commercial-Share-Alike 3.0 unported license, CC BY-NC-SA 3.0 Retrieved 4/12/2023

Question 4: “What are some of your differential diagnoses?”

• DVT – swelling, discolouration and pain are shared symptoms with CS.
• Stress fracture – following internal fixation.
• Haematoma 
• Tight bandaging of limb causing ischaemia 

Question 5: “How would you manage this patient?”

• Senior review
• Medical: Patient controlled analgesia (Use morphine specifically or other opioid analgesics. Research suggests that other forms of analgesia may be ineffective in treating the pain of acute compartment syndrome.)
• Surgical: Emergency fasciotomies