Greenstick fracture

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohammadmain Rezazadehsaatlou[2].

Overview

A greenstick fracture, as an incomplete fracture of long bones, defined as a partial thickness fracture which just the cortex and periosteum are interrupted only on one side of the affected bone. The greenstick fracture usually are seen in young children commonly younger than 10 years old..

is a broken bone that is most common with children. It is usually from one small fall or blow to one side of the body was the cause of a injury. The term greenstick is derived from an analogy between the pliable bones of children and the flexible nature of a young twig. It does not usually heal after one week. 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. Greenstick fractures are especially common in children suffering from rickets.

Historical Perspective

The term greenstick is originates from an analogy between the pliable bones and the flexible nature of a young twig.

In 1822, Sir Astley Cooper worked on the dislocations and Fracture of human body.

In 1930–2000, John Nevil Insall, An american-British orthopedic surgeon discovered the green-stick fracture.

Causes

The main etiology of the greenstick fracture is thought to be a loading may be placed on a forearm during falling onto an outstretched hand (FOOSH) with an extended wrist and hyperpronated forearm. Because at this posture the energy from the radius fracture transmitted towards the radioulnar joint cause the dislocation of the DRUJ.

Pathophysiology

Mechanism

The greenstick fracture is caused by a fall on the outstretched hands with the wrist in dorsiflexion position. The form and severity of this fracture depends on the position of the wrist at the moment of hitting the ground. The width of this mentioned angle affects the localization of the fracture. Pronation, supination and abduction positions leads the direction of the force and the compression of carpus and different appearances of injury. Pathophysiology Its known that the greenstick fracture in normal healthy adults can be caused due to the high-energy trauma (e.g., motor vehicle accidents), sport related injuries, falling from height. But it should be noted that the most important Risk factors for insufficiency fractures is chronic metabolic disease such as steoporosis, osteopenia, eating-disordered behavior, higher age, prolonged corticosteroid usage, female gender, lower BMI, history of a recent falling, and prior fracture.

Pathophysiology

• The pattern of bone fracture and severity of injury depends on variety of factors such as:
• Patients age
• Patients Weight
• Patients past medical history specifically any bone diseases affecting the quality of bone (such as osteoporosis, malignancies)
• Energy of trauma
• Bone quality
• Position of the specific organ during the trauma
• The below-mentioned processes cause decreased bone mass density:
• Autophagy is the mechanism through which osteocytes evade oxidative stress.
• The capability of autophagy in cells decreases as they age, a major factor of aging.
• As osteocytes grow, viability of cells decrease thereby decreasing the bone mass density

Differentiating greenstick fracture from other Diseases

In the orthopedic medicine its important to know that the forearm fracture should be evaluated using radiography for both confirming diagnosis and also for evaluating the surrounding tissues.

Related Chapters

• Monteggia fracture

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. Nomally the prognosis is very good for this kind of fracture since the thick periosteum will act as a splint and immobilise the defect. Children also have good remodelling capability.

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, for example 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 overstraighten 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

Prognosis following non-operative treatment is 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 Fractures of the Forearm Wheeless' Textbook of Orthopaedics
• Forearm Fractures in Children Patient Information from AAOS
• Fractures Patient Information from AAOS