Bone remodeling is initiated when osteoclast precursor cells are recruited to the altered bone surface (black stellate cells) and fuse to form mature, bone resorbing osteoclasts (red cells) that attach to the surface.

Osteoblasts are specialized bone-forming cells that express parathyroid hormone (PTH) receptors and have several important roles in bone remodeling: expression of osteoclastogenic factors, production of bone matrix proteins, and bone mineralization (16).

The growth hormone/IGF-1 system stimulates both the bone-resorbing and bone-forming cells, but the dominant effect is on bone formation, thus resulting in an increase in bone mass. Thyroid hormones increase the energy production of all body cells, including bone cells.

Bone development continues throughout adulthood. Even after adult stature is attained, bone development continues for repair of fractures and for remodeling to meet changing lifestyles. Osteoblasts, osteocytes and osteoclasts are the three cell types involved in the development, growth and remodeling of bones.

Definition. Bone remodelling is the continuous metabolic process of bone breakdown (resorption) by specialised cells called osteoclasts, followed by formation of new bone tissue (ossification) by cells called osteoblasts.

There are four stages in the repair of a broken bone: 1) the formation of hematoma at the break, 2) the formation of a fibrocartilaginous callus, 3) the formation of a bony callus, and 4) remodeling and addition of compact bone.

In normal bone the duration of the remodeling cycle in cortical is shorter than in cancellous bone with a median of 120 days [6]. The total surface of cancellous bone is completely remodeled over a period of 2 years.

Bone generally takes 6 to 8 weeks to heal to a significant degree. In general, children’s bones heal faster than those of adults.

The pain may feel like a sharp, stabbing pain. The pain also worsens if pressure is placed on it. As your bone heals, this decreases. If you have a cast placed around the area, you will likely feel almost no pain anymore because the bone is stabilized.

Ignoring a hairline fracture can lead to a more serious fracture or break occurring, which is more difficult to treat. If not treated or ignored, the hairline may not heal, resulting in a non-union fracture.

Causes and Risk Factors Blood brings oxygen, healing cells and growth factors to the bone to allow it to heal. If a fractured bone is left unstable or lacks blood supply, it can lead to a nonunion. Factors including the use of tobacco or nicotine can impede bone healing and increase the risk of nonunion.

Symptoms of a fracture that is not healing normally include tenderness, swelling, and an aching pain that may be felt deep within the affected bone. Often, the bone isn’t strong enough to bear weight, and you may not be able to use the affected body part until the bone heals.

Casts and splints can hold broken bones in place while they heal. New hard bone forms in about 3–6 weeks, and the cast or splint usually can come off.

Treatment of Metatarsal Fractures

1. Rest. Sometimes rest is the only treatment needed to promote healing of a stress or traumatic fracture of a metatarsal bone.
2. Avoid the offending activity.
3. Immobilization, casting or rigid shoe.
4. Surgery.
5. Follow-up care.

Acute metatarsal fracture May make an audible sound at the time of the break and you will usually have immediate pain and tenderness around the area of the fracture. The pain is often called ‘pinpoint pain’ as it is quite well localised at the site of impact to the bone.

If you have a broken foot, you may experience some of the following signs and symptoms:

1. Immediate, throbbing pain.
2. Pain that increases with activity and decreases with rest.
3. Swelling.
4. Bruising.
5. Tenderness.
6. Deformity.
7. Difficulty in walking or bearing weight.

How to Heal Quickly from a Stress Fracture?

1. Apply ice and take pain medications to control symptoms.
2. Use a cast or splint to protect the stress fracture site.
3. Start partial weight bearing only when pain free.
4. Increase your activity to avoid recurrence of fracture.

Treatment depends on the location of the stress fracture. Most stress fractures will heal if you reduce your level of activity and wear protective footwear for 2 to 4 weeks.

Treatment for a hairline fracture looks different than that of a more severe fracture. You likely won’t need a cast, but the doctor may recommend that you wear a brace to keep your arm immobile. You should also rest your arm and use ice to control the pain.

Chronic Pain – After Healing is Complete Many people who fracture will eventually heal and recover to the point where they no longer experience any pain. However, some people may continue to experience pain long after the fracture and soft tissues have healed.

While many people believe that a fracture is a “hairline break,” or a certain type of broken bone, this is not true. A fracture and a broken bone are the same things. To your physician, these words can be used interchangeably.

Technically speaking, the answer to the question “can broken bones heal without a cast?” is yes. Assuming conditions are just right, a broken bone can heal without a cast. However, (and very importantly) it doesn’t work in all cases. Likewise, a broken bone left to heal without a cast may heal improperly.

However, these stages have considerable overlap.

• Hematoma Formation (Days 1 to 5)
• Fibrocartilaginous Callus Formation (Days 5 to 11)
• Bony Callus Formation (Days 11 to 28)
• Bone Remodelling (Day 18 onwards, lasting months to years)

Broken Foot Symptoms Usually (but not always) the pain is so bad, that you are not able to walk. Broken bones in the toes cause less pain, and you may be able to walk with a broken toe. Bruising of the foot with a broken bone is also common.

To heal, a broken bone must be immobilized so that its ends can knit back together. In most cases, this requires a cast. Minor foot fractures may only need a removable brace, boot or shoe with a stiff sole. A fractured toe is usually taped to a neighboring toe, with a piece of gauze between them.