Fracture: Understanding Your Pathology Report
A fracture is a break in a bone. Most fractures result from an injury, such as a fall or a car accident, and are diagnosed with an X-ray. They do not usually need to be examined by a pathologist.
A pathology report for a fracture is produced when surgeons remove broken bone during surgery, most often during a hip replacement. The pathologist examines the bone to see how the fracture was healing and, most importantly, to check whether an underlying disease weakened the bone and allowed it to break.
This article explains why broken bone is sent to a pathologist and what the findings in your pathology report mean.
Why was my broken bone sent to a pathologist?
When a surgeon removes broken bone, they usually examine it under a microscope. The main reason is to look for a bone disease that may have caused the fracture. Finding such a disease can change your treatment.
The most common situation is a hip fracture in an older adult. The top of the thigh bone, called the femoral head, is often removed and replaced with an artificial joint. The pathology lab then receives the removed bone.
In most cases, the report shows a fracture with healing changes and thin bone, without any other disease. This is reassuring.
What is a pathologic fracture?
A pathologic fracture is a break through bone that was already weakened by disease. Because the bone is weaker than normal, it can break with little force, such as a minor fall or even ordinary activity. Conditions that can weaken bone include:
- Osteoporosis. This is the most common cause. The bones become thin and fragile, so they break more easily. Osteoporosis is most common in older adults, especially women after menopause.
- Cancer that has spread to bone. In adults, cancer in a bone has usually spread there from somewhere else, which is called metastasis. The cancers that most often spread to bone start in the breast, prostate, lung, kidney, and thyroid.
- Cancers of the blood and immune system. Multiple myeloma commonly weakens bone in adults. Lymphoma can involve bone at any age.
- Tumors that start in bone. These include noncancerous tumors such as an enchondroma or a giant cell tumor of bone. They also include bone cancers such as osteosarcoma, which is more common in children and young adults.
- Infection. A bone infection, called osteomyelitis, can weaken it.
- Medications. Long-term use of steroid medicines can thin the bones.
What are the types of fracture?
Your doctors may describe your fracture using one of these terms:
- Closed fracture. The bone is broken, but the skin over it is intact.
- Open fracture. The broken bone has pierced the skin, or a wound reaches down to the bone. This raises the risk of infection. Previously called a compound fracture.
- Displaced fracture. The broken ends of the bone no longer line up.
- Comminuted fracture. The bone has broken into several pieces.
- Stress fracture—a small crack caused by repeated force rather than a single injury. Stress fractures are common in runners and other athletes, especially in the feet and lower legs.
- Greenstick fracture. An incomplete break that occurs in the softer bones of children.
- Pathologic fracture. A break through bone weakened by disease, as described above.
How does a fracture heal?
A broken bone heals in stages, and the pathologist can see which stage was reached. This helps estimate how long ago the fracture happened.
- Bleeding and inflammation. Within the first days, blood collects around the break, and immune cells arrive to clear away damaged tissue. Pathologists call this acute inflammation. Bone at the broken edges dies because its blood supply is cut off, and your report may call it necrotic or nonviable bone.
- Soft callus. Over the next few weeks, new tissue containing cartilage and fibrous tissue forms a bridge across the break. This bridge is called a callus.
- Hard callus. Over several weeks to months, the callus is gradually replaced by new bone. This new bone is less organized than normal bone.
- Remodeling. Over months to years, the new bone is reshaped into strong, well-organized bone.
What does the pathologist look for?
When examining broken bone, the pathologist looks for three things:
- Healing changes. The stage of healing helps estimate how long ago the fracture occurred.
- Bone quality. Thin bone with fewer and thinner support struts suggests osteoporosis or a milder form called osteopenia.
- Underlying disease. Most importantly, the pathologist looks for cancer, infection, or another condition that may have caused the fracture.
The report may also comment on the bone marrow inside the bone. A finding of trilineage hematopoiesis means the marrow is making all three main types of blood cells normally. This is a normal finding.
Can a healing fracture look like cancer?
Yes. A healing fracture contains many rapidly growing cells that are building new bone and cartilage. Under the microscope, this busy healing tissue can look similar to a bone cancer such as osteosarcoma.
Pathologists are trained to recognize this and account for it. Your pathologist will also consider your X-rays and medical history. A report that describes healing callus without any other disease means that no cancer was found.
What happens if cancer is found?
If the pathologist finds cancer in the bone, the report will describe the type of cancer and, when possible, where it started in the body. Additional tissue tests, such as immunohistochemistry, may be done to identify the cancer.
Your care team will then arrange further tests and treatment. Finding cancer at the site of a fracture changes the plan, so your doctors will discuss the result with you directly.
What is the prognosis?
For a fracture caused by an injury or by osteoporosis, the outlook depends on the bone involved, your age, and your general health. Most fractures heal well with treatment.
A hip fracture in an older adult is a serious injury, and recovery can take months. Treatment of osteoporosis after a fracture lowers the chance of another one.
When a fracture is caused by an underlying disease such as cancer, the outlook depends on that disease rather than on the fracture itself.
What happens after the diagnosis?
- Treatment of the fracture. Depending on the bone and the type of break, treatment may include a cast or splint, surgery with plates, rods, or screws, or joint replacement.
- Rehabilitation. Physiotherapy helps restore strength and movement after the bone heals.
- Bone health assessment. After a fracture caused by little force, your doctor may arrange a bone density scan and discuss treatment for osteoporosis.
- Further testing. If the pathology report shows an underlying disease, your care team will arrange the appropriate tests and treatment.
Questions to ask your doctor
- Did the pathology report find anything that may have caused my fracture?
- Does my report show signs of osteoporosis?
- Should I have a bone density test?
- What can I do to lower the risk of another fracture?
- How long will recovery take, and when can I return to normal activity?