Types of bone fractures: names, patterns and diagrams

A bone fracture is a broken bone. Fracture, break and crack all mean the same thing: doctors use "break" and "fracture" interchangeably. A bone can be fractured completely or only partly, and it can break crosswise, lengthwise or into several pieces. (AAOS OrthoInfo: Fractures (Broken Bones).)

Most fracture names describe a long bone, so its parts are worth knowing. The shaft is the diaphysis, a tube of hard compact bone around the medullary (marrow) cavity. Each end is an epiphysis. A membrane called the periosteum covers the outside, and tendons and ligaments attach to bone there. (OpenStax Anatomy and Physiology 2e, 6.3 Bone Structure.)

Between the shaft and each end is the metaphysis, the flared part of the bone where it widens; in a growing bone a layer of cartilage, the growth plate (epiphyseal plate, physis), separates the metaphysis from the epiphysis. (StatPearls: Greenstick Fracture.)

Fracture names combine. Doctors describe the type of fracture line, where it is in the bone, how far the pieces have moved and whether the skin is broken, so one fracture can be, for example, an open transverse fracture of the midshaft. (Merck Manual Professional Version: Overview of Fractures.)

For the parts of a long bone in more detail, with diagrams, see the bone structure guide.

There is no single official number. OpenStax's anatomy textbook lists 8 common types, the American Academy of Orthopaedic Surgeons (AAOS) lists 5 common types, and the MSD Manual's table explains 21 fracture terms. The lists differ because each name describes a different feature of the same break. (OpenStax Anatomy and Physiology 2e, 6.5 Fractures: Bone Repair.)

It is easier to sort fractures by the question each name answers. Cleveland Clinic groups them by pattern, by how they happened, as open or closed, and as displaced or non-displaced, and Merck's manual describes the fracture line, its location and the displacement of the pieces. (Cleveland Clinic: Bone Fractures (Broken Bones).)

1. Is the skin broken?: Open (compound) or closed (simple). (OpenStax Anatomy and Physiology 2e, 6.5 Fractures: Bone Repair.)
2. Is the bone broken all the way through?: Complete, or incomplete like a greenstick or buckle fracture. (Radiopaedia: Complete fracture.)
3. What shape is the break line?: Transverse, oblique, spiral, comminuted, segmental, impacted or longitudinal. (Merck Manual Professional Version: Overview of Fractures.)
4. Have the pieces moved?: Displaced or non-displaced. (Cleveland Clinic: Bone Fractures (Broken Bones).)
5. What caused it?: Stress, avulsion, compression or pathological fractures. (Cleveland Clinic: Bone Fractures (Broken Bones).)
6. Is it a child's bone?: Greenstick, buckle and growth plate fractures happen in children. (Merck Manual Professional Version: Overview of Fractures.)

An open fracture is one where the skin is broken so that the fracture connects with the outside. Either a bone fragment sticks out through the skin, or a wound reaches down to the broken bone; the bone may or may not be visible. In a closed fracture the skin over the break is intact. (AAOS OrthoInfo: Fractures (Broken Bones).)

The skin wound does not have to sit directly over the break: StatPearls notes it may lie some distance away, so any fracture that comes with a wound is treated as open until shown otherwise. (StatPearls: Open Fracture Management.)

Compound is another name for an open fracture, and simple is another name for a closed one. Simple only means the skin is intact: closed fractures can still be serious. Open fractures carry a high risk of infection, in the wound and in the bone itself. (OpenStax Anatomy and Physiology 2e, 6.5 Fractures: Bone Repair.)

In a complete fracture the bone is broken all the way round its outer wall (cortex), so the pieces are fully separated. Transverse, oblique, spiral, longitudinal and comminuted fractures are all complete fractures. (Radiopaedia: Complete fracture.)

In an incomplete fracture the bone is not broken across its whole width, so the pieces do not come apart. Incomplete fractures happen mainly in children's long bones and include greenstick, buckle (torus) and bowing fractures. When the force only slightly exceeds a bone's breaking point, the bone may crack rather than break all the way through. (Radiopaedia: Incomplete fracture.)

Pattern names describe the shape of the break line, what the break looks like. Transverse and oblique fractures break in a straight line; spiral, comminuted, segmental and greenstick fractures have an uneven break line. (Cleveland Clinic: Bone Fractures (Broken Bones).)

To see the long bones these patterns are drawn on, open the leg bones guide.

In a displaced fracture the broken pieces have moved so that they no longer line up, often leaving a gap. In a non-displaced fracture the pieces are still in their normal position with no space between them; AAOS also calls this a stable fracture. A non-displaced fracture is still a broken bone. (Cleveland Clinic: Bone Fractures (Broken Bones).)

Doctors describe displacement more exactly. An angulated fracture is one where the pieces lie at an angle to each other; Merck's manual measures angulation as the angle of the far (distal) piece from the near (proximal) one, and uses distraction for pieces pulled apart along the bone's length. (MSD Manual Consumer Version: Overview of Fractures.)

Some fractures are named for how they happened rather than for the shape of the break. Trauma, such as a fall, a road crash or a sports injury, causes most fractures; the four types below are named for the way the force acted or for the state of the bone that broke. (Cleveland Clinic: Bone Fractures (Broken Bones).)

Children's bones break differently from adults'. Growing bone contains more cartilage, is more flexible, has a thicker periosteum and has open growth plates, so it tends to bend under load instead of breaking right through. (StatPearls: Greenstick Fracture.)

StatPearls describes a spectrum. With no break through the cortex, the bone either bends (a bowing, or plastic deformation, fracture) or kinks (a buckle fracture). If one cortex breaks it is a greenstick fracture, and if both break it is a complete fracture. (StatPearls: Pediatric Torus Buckle Fracture.)

For the forearm bone most often involved in children's wrist fractures, see the radius guide.

Fractures are also named for the bone and the part of it that broke. Merck's manual describes the location as the epiphysis (the bone end), the metaphysis (the neck between end and shaft) or the diaphysis, the shaft, which is divided into proximal, middle and distal thirds. (Merck Manual Professional Version: Overview of Fractures.)

A fracture that extends into a joint is an intra-articular (joint) fracture. It breaks the cartilage covering the bone ends, so the joint may move less well and osteoarthritis becomes more likely later. (MSD Manual Consumer Version: Overview of Fractures.)

When a joint is dislocated and one of its bones is also broken, the injury is called a fracture-dislocation. (Medical News Today: Fractures: Types, causes, symptoms, and treatment.)

Some bones have their own risks because of their anatomy. A scaphoid fracture in the wrist may not show on the first X-rays, and it can cut off part of the bone's blood supply so that the piece dies (osteonecrosis); displaced fractures of the femoral neck carry the same risk. (MSD Manual Consumer Version: Overview of Fractures.)

Some common fractures carry a person's name: the Colles fracture, a break across the distal radius often caused by a fall onto an outstretched hand, is the most frequent forearm fracture (see the radius guide for Colles and Smith fractures). (OpenStax Anatomy and Physiology 2e, 8.2 Bones of the Upper Limb.)

Our bone guides cover the fractures of each bone in context: the femur, tibia and fibula in the leg, the radius, ulna and humerus in the arm, the foot bones, the hand bones and the skull bones.

To find any bone of the body in 3D, use the skeletal system guide.

A broken bone heals in four overlapping steps. Blood from torn vessels clots into a fracture haematoma. A soft callus of cartilage and new bone then forms inside and around the break and stabilises it. The cartilage is replaced by spongy (trabecular) bone, and finally the bone is remodelled back towards its original shape. (OpenStax Anatomy and Physiology 2e, 6.5 Fractures: Bone Repair.)

Clinical manuals group the same process into three stages: inflammation, repair and remodelling. Inflammation starts straight away and peaks within a couple of days. Repair begins within days and lasts weeks to months as the callus forms. Remodelling takes many months. (MSD Manual Consumer Version: Overview of Fractures.)

Children heal much faster than adults, and conditions that reduce blood flow, such as diabetes and peripheral vascular disease, slow healing. Setting a broken bone back in place is called reduction: closed reduction without surgery, open reduction with surgery to expose the break. (Merck Manual Professional Version: Overview of Fractures.)

Healing does not always go to plan. A fracture that heals more slowly than expected has delayed union; one that does not heal at all is a non-union; and one that heals with the pieces in the wrong position, leaving a deformity, is a malunion. Among the main reasons a fracture heals poorly are a damaged blood supply and a break that is not kept still enough. (Merck Manual Professional Version: Overview of Fractures.)

This guide explains names and anatomy only. If you think you have broken a bone, see a clinician: only an examination and imaging can show the type of fracture and the right treatment. (AAOS OrthoInfo: Fractures (Broken Bones).)

For bone and cartilage as tissues, see the tissue types guide.