Complex Regional Pain Syndrome (CRPS)

Synonyms:

Reflex sympethatic Dystrophy Syndrome (RSDS), Sudeck's Atrophy, Causalgia, Shoulder-Hand Syndrome, Posttraumatic Dystrophy, Sympathetic maintained pain syndrome

History:

• 
  
  Recognized since the Civil War when it was called causalgia, a name chosen to describe intense, burning extremity pain after an injury.
  
• 
  
  Bonica coined the term reflex sympathetic dystrophy in 1953
  

Incidence:

1% of all conservatively treated distal radius fractures and up to 5% of operatively treated fractures.

Types:

• 
  
  CRPS type I
  
  • 
    
    secondary to an identifiable neurologic compression or injury.
    
  • 
    
    e.g. ulnar nerve axonotemesis or a superficial radial nerve injury due to trauma from an external fixator pin.
    
• 
  
  CRPS type II
  
  • 
    
    no identifiable neurological injury
    
  • 
    
    sympathetically mediated pain
    

Stages:

Acute:

• 
  
  6-12 wks
  
• 
  
  persistent burning pain
  
• 
  
  trivial injury followed by severe & out of proportion pain
  
• 
  
  Localised pain, later spreads throughout extremity
  
• 
  
  Hypersensitivity to light touch
  
• 
  
  Extremity swollen & warm
  
• 
  
  Excessive perspiration
  

Dystrophic

• 
  
  Affected joint ROM restricted
  
• 
  
  Involved area becomes cool
  

Atrophic

• 
  
  Skin & muscle atrophy
  
• 
  
  Skin dry, shiny, glossy
  
• 
  
  Stiffness, intractable pain persists several weeks
  

Diagnosis:

• 
  
  Identify for CRPS type I or CRPS type II.
  
• 
  
  determine if it is a treatable source (type I).
  
• 
  
  Persistent burning pain after an injury is characteristic.
  
• 
  
  most common lesion with type I is median nerve injury, due to direct trauma or an undiagnosed compressive neuropathy.
  
• 
  
  causes are injury to the ulnar nerve, the superficial radial nerve, the intercarpal ligament, or the triangular fibrocartilage.
  
• 
  
  delayed union, incomplete union, and nonunion may also contribute to symptoms.
  
• 
  
  X-ray – Patchy Osteoporosis
  
• 
  
  Peripheral nerve conduction studies e.g. compression points around the elbow are useful, also evaluate the ulnar nerve.
  
• 
  
  MRI may show an incomplete union, carpal injuries, or TFCC injury.
  
• 
  
  Arthroscopic reveal arthrofibrosis and/or TFCC injuries.
  
• 
  
  Bone Scan +ve, showing regional uptake reflects ncreased blood flow
  

Treatment:

• 
  
  Prevention, immediate attention, control pain & swelling.
  
• 
  
  Restoration of motion by exercise
  
• 
  
  Active use of extremity despite pain
  
• 
  
  Edema control by limb elevation
  
• 
  
  Physiotherapy
  
• 
  
  Drugs: antidepressants, corticosteroids, calcium channel blockers
  

CRPS Type I:

Surgical treatment:

• 
  
  Neurolysis aimed at external compression of the median and ulnar nerve injuries.
  
• 
  
  Adjunctive grafting or Barrier wrapping for injury to sensory branches of the superficial radial or dorsal ulnar nerve.
  
• 
  
  Neuroma resection proximally and nerve stump can be buried in appropriate soft tissue.
  
• 
  
  External bone stimulators or revision osteosynthesis for an incomplete union.
  

CRPS type II

• 
  
  Multifaceted, aimed at restoring ANS control and improving physical function.
  
• 
  
  Early recognition and regional blockade with physical therapy is useful.
  

Medical management

• 
  
  guided by the appearance of the hand and wrist (Early phases marked by erythema and swelling, later phases, they may appear cool and atrophic.
  
• 
  
  For warm, swollen erythematous hand, treatment include gabapentin, selective serotonin reuptake inhibitors, or clonidine hydrochloride.
  
• 
  
  In later stages, the aim is to improve blood flow, using nifedipine or selective serotonin reuptake inhibitors.
  

Physical therapy

• 
  
  mobilizing the wrist and digits.
  
• 
  
  Focus is to improve wrist extension, causing greater mechanical advantage.
  
• 
  
  Adjunctive modalities such as dynamic or serial static splinting may prove effective at mobilizing the wrist and the metacarpophalangeal joints.
  

Prognosis

• 
  
  Recovery after CRPS treatment varies.
  
• 
  
  the prognosis for CRPS type I is better than that of CRPS type II.
  
• 
  
  When the syndrome continues for more than 1 year, it is likely that residual impairment will be present.
  
• 
  
  Regardless of the treatment afforded, patients experience delayed recovery.