Distal Radial Physeal Fracture
The peak age for injury to the growth plate is in the pre-adolescent growth spurt.
The Salter-Harris type II fracture is the most common type. Commonly there is an associated ulna fracture (greenstick, physeal or styloid).
Distal radial physeal fractures are uncommon in children younger than five years.
Physeal fractures are classified by the Salter-Harris classification (Type I, type II, type III, type IV & type V) and whether the radius, ulna, or both bones are injured.
Radial physeal fractures can occur in isolation or be associated with an ulna fracture (greenstick, physeal, or styloid).
The most common mechanism of injury is a fall on an outstretched hand. Extension of the wrist at the time of injury causes the distal fragment to be displaced dorsally (posteriorly).
There is usually pain and tenderness directly over the fracture site, and limited range of motion in the wrist and hand.
There may be little if any swelling.
The deformity depends on the degree of physeal displacement.
Remember to always examine the elbow for associated injuries
All fractures should be assessed using the Advanced Trauma Life Support (ATLS) principles to ensure associated and potentially significant injuries are identified.
Appropriate analgesia and splinting for pain relief before the x-ray is required.
A ‘wrist x-ray’ request will provide anteroposterior (AP) and lateral views of the distal forearm and wrist.
If the injury is to the mid-forearm or the pain is poorly localized, a ‘forearm x-ray’ should be ordered.
Avoid ordering ‘x-ray arm’ as it is better to have images focused on the region of local tenderness.
If there are any elbow joint symptoms, an ‘elbow x-ray’ should be ordered as some fractures around the elbow can be difficult to detect.
If, in an older child with a painful wrist (as a result of a fall on an outstretched hand), there is no distal radial fracture seen on x-ray, consider the possibility of a scaphoid fracture.
Examine for tenderness in the anatomical snuff box and consider ordering scaphoid views.
In general, distal radial physeal fractures that are angulated >20 degrees (as seen on the lateral x-ray) need to be reduced.
Angulation is less acceptable if there are less than two years of growth remaining.
More angulation can be accepted in children less than eight years old and those presenting late.
For patients who have a delayed presentation of physeal fracture >5 days, it is not advisable to attempt closed reduction, as this increases the risk of growth plate injury.
Most of the children with undisplaced and minimally displaced fracture (SH type I &II) in children less than 10 years of age are managed with closed manipulation and above elbow cast immobilization.
Operative treatment is indicated:
Children more than 10 years of age
Salter-Harris types III and IV
Neurovascular injury with fracture
Extreme swelling/compartment syndrome
Unable to achieve or maintain reduction
Ipsilateral upper extremity fracture
Emphasis should be placed on the elevation of the limb (elbow above the heart) for the first 48 hours and active finger mobilization.
Back slab and sling should be worn under clothing and not through the sleeve.
For displaced fractures, the need for close follow-up should be emphasized due to the risk of loss of reduction.
The wrist has extensive remodelling potential. The risk of physeal arrest is rare in young children but the risk is higher if the child is near the end of growth. Salter-Harris type I and II injuries rarely lead to growth problems. The risk of growth arrest is higher in Salter-Harris type III, IV and V.
The overall risk of physeal arrest after distal radial physeal fracture is approximately 4%.
The higher the Salter-Harris fracture classification number, the greater the chances of growth arrest.
Malunion can occur if the fracture is mal-reduced or reduction is lost without close follow-up.
Compartment syndrome due to restriction by the cast.
Median nerve neuropathy.