A greenstick fracture is a bone fracture seen almost exclusively in children. The term greenstick is derived from an analogy between the pliable bones of children and the flexible nature of a young twig. Greenstick fractures are usually the result of direct trauma to the bone, and are only "partial" fractures, in which the bone does not completely break through. Often, since these fractures are so stable, a simple application of force using one's thumbs is all that is needed for reduction. Because of children's great capacity to mend their bones, these fractures often have an excellent prognosis.
Definition
When a
sappy (green) twig or branch is bent beyond its failure point, one side tends to break but the other remains in continuity and bends. The bones of children under age 13 are similarly "bendable" and may break with the "greenstick" pattern — one
cortex of the bone
fracturing and the other deforming.
Synonyms
A torus fracture is a specific type of greenstick fracture in which the bone is compressed to form a ring (torus) of compressed injured bone but there is little angular deformity.
Incidence
Extremely common
Pathogenesis and risk factors
The greenstick fracture pattern occurs as a result of bending forces. Activities with a high risk of falling are risk factors.
Non Accidental Injury more commonly causes spiral (twisting) fractures but a blow on the forearm or shin could cause a greenstick fracture.
Natural history/untreated prognosis
Greenstick fractures almost always heal. Because part of the bone is in continuity the fracture fragments do not move so the pain from the injury improves quickly and the fracture is stable (increased deformity is not likely). However, most greenstick fractures have angular deformity and this will persist. The bone may remodel (grow straight) but not always and not when the deformity is marked. The other reason to recommend treatment is that the healing bone is weak and the unprotected fracture can be converted to a completely displaced injury if the child falls.
Clinical features
The child and/or its caregivers will usually describe significant injury with a bending force eg a fall or a blow with impact from the side. The limb will be painful and is often swollen and deformed. The child will rarely still be able to use the limb or walk on it; usually it is too sore. Examination will show tenderness and angulation at the fracture site as well as pain on moving the limb or rotating it. Circulation and sensation are usually intact.
Investigation
The affected bone and the joints above and below should be x-rayed. This will show the characteristic fracture pattern.
Non-operative treatment
Standard treatment is closed
reduction and
cast application. The hallmark of a greenstick fracture is angulation at the fracture site and this should be straightened. Because this would be painful the child should be anaesthetised or the limb made painless with
regional anaesthesia. As noted above
fracture reduction is straightforward; pressure is applied to the apex of the deformity and the bone straightens. If necessary some traction may also be applied. It is difficult to over-straighten a greenstick fracture because the cortex on the concave side of the bone is still intact and cannot be distracted. Following reduction the limb is placed in a cast. The cast is usually in place for three weeks or more depending on the state of
bone healing. This is followed by a period of activity restriction and rehabilitation. It is not usually necessary to have formal
physiotherapy.
Risks of non-operative treatment
Inadequate reduction may cause persistent deformity. Casts that are too tight can cause
compartment syndrome.
Prognosis following non-operative treatment
Excellent. Healing of a greenstick fracture is almost universal so the
prognosis depends on the adequacy of the
reduction and avoiding
complications of treatment.
Operative treatment
Indications for surgery in a greenstick fracture amount to failure to obtain a satisfactory
reduction. Surgery would consist of open reduction; fixation would usually still be by cast rather than internal fixation. This is extremely rare. An open greenstick fracture is also very rare but in that case surgery to clean up the wound would be needed.
External links
Greenstick Fracture is also a Pop/Punk band out of Dayton, Ohio. The members include Josh Vest, Dennis Martin and Dan Reder.