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Fracture and dislocations-sign and symptoms, diagnostic tests, bone healing process

CLINICAL MANIFESTATIONS

1)      Local bleeding

2)      Swelling and discoloration

Localized swelling and discoloration of the skin (ecchymosis) occurs after a fracture as a result of trauma and bleeding into the tissues.

3)      Pain and tenderness

The pain is continuous and increases in severity until the bone fragments are immobilized.

4)      Loss of function

After a fracture, the extremity cannot function properly, because normal function of the muscles depends on the integrity of the bones to which they are attached. Pain contributes to the loss of function. In addition, abnormal movement (false motion) may be present.

5)      Deformity

Displacement, angulation, or rotation of the fragments in a fracture of the arm or leg causes a deformity (either visible or palpable) that is detectable when the limb is compared with the uninjured extremity. Deformity also results from soft tissue swelling.

6)      Shortening

In fractures of long bones, there is actual shortening of the extremity because of the contraction of the muscles that are attached above and below the site of the fracture. The fragments often overlap by as much as 2.5 to 5 cm (1 to 2 inches).

7)      Crepitus

A grating sensation, called crepitus, can be felt caused by the rubbing of the bone fragments against each other.

DIAGNOSTIC TESTS

  • History taking
  • Physical symptoms
  • X-ray shows fracture
  • Hemogram

a) Complete Blood Count: Hematocrit may increase or decrease. Increase WBC is a normal response to stress

b) Urine creatinine (Cr) clearance: Muscle trauma increases load of Cr for renal clearance

c) Coagulation profile

  • CT scan
  • MRI

BONE HEALING PROCESS

Most fractures heal through a combination of intramembranous and endochondral ossification processes. When a bone is fractured, the bone fragments are not merely patched together with scar tissue. Instead, the bone regenerates itself.

Fracture healing occurs in four areas, including

Bone marrow, where endothelial cells rapidly undergo transformation and become osteoblastic bone-forming cells

Bone cortex, where new osteons are formed

Periosteum, where a hard callus/bone is formed through intramembranous ossification peripheral to the fracture, and where a cartilage model is formed through endochondral ossification adjacent to the fracture site

External soft tissue, where a bridging callus (fibrous tissue) stabilizes the fracture

Buckwalter (2000) summarized the process of fracture healing into six stages stimulated by the release and activation of biologic regulators and signaling molecules

1. Hematoma and inflammation: The body’s response is similar to that after injury elsewhere in the body. There is bleeding into the injured tissue and formation of a fracture hematoma. The hematoma is the source of signaling molecules, such as cytokines, transforming growth factor-beta (TGF-β), and platelet-derived growth factor (PDGF), which initiate the fracture healing processes. The fracture fragment ends become devitalized because of the interrupted blood supply. The injured area is invaded by macrophages (large white blood cells), which débride the area. Inflammation, swelling, and pain are present. The inflammatory stage lasts several days and resolves with a decrease in pain and swelling.

 2.Angiogenesis and cartilage formation:Under the influence of signaling molecules, cell proliferation and differentiation occur. Blood vessels and cartilage overlie the fracture.

3. Cartilage calcification:Chondrocytes in the cartilage callus form matrix vesicles, which regulate calcification of the cartilage. Enzymes within these matrix vesicles prepare the cartilage for calcium release and deposit.

4. Cartilage removal:The calcified cartilage is invaded by blood vessels and becomes resorbed by chondroblasts and osteoclasts. It is replaced by woven bone similar to that of the growth plate.

5. Bone formation: Minerals continue to be deposited until the bone is firmly reunited. With major adult long bone fractures, ossification takes 3 to 4 months.

6. Remodeling:The final stage of fracture repair consists of remodeling the new bone into its former structural arrangement.Remodeling may take months to years, dependingon the extent of bone modification needed, the function ofthe bone, and the functional stresses on the bone. Cancellousbone heals and remodels more rapidly than does compactcortical bone.

Duration for Bone Healing
The time required for bone healing can be affected by many factors, including the type of fracture and the patient’s age, underlying medical conditions, and nutritional status. Bone generally takes 6 to 8 weeks to heal to a significant degree. In general, children’s bones heal faster than those of adults.

Factors Hindering Bone Healing
A wide variety of factors can slow down the healing process. These include

  • Movement of the bone fragments; weightbearing too soon
  • Smoking, which constricts the blood vessels and decreases circulation
  • Medical conditions, such as diabetes, hormone-related problems, or vascular disease
  • Some medications, such as corticosteroids and other immunosuppressants
  • Fractures that are severe, complicated, or become infected
  • Advanced age
  • Poor nutrition or impaired metabolism

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