Key points of imaging examination after bone plate fixation

After bone plate fixation, imaging examination is a key means to evaluate fracture healing, internal fixation status and complications. The following are the core points of imaging examinations, which need to be comprehensively judged in combination with clinical conditions:

First, check the time and frequency

Immediate postoperative examination

X-ray examination should be conducted immediately after the operation to confirm the position of the bone plate, the distribution of screws and the reduction of fractures, and to rule out intraoperative fracture displacement or internal fixation errors.

Early follow-up (1-2 weeks after the operation)

Reexamination of X-rays was conducted to evaluate the regression of soft tissue swelling and the stability of internal fixation, and to observe whether there was early screw loosening or bone plate displacement.

Mid-term review (4-6 weeks after the operation)

The formation of callus at the fracture end was observed through X-ray or CT to judge the fracture healing process and adjust the rehabilitation plan.

Follow-up examination (3 to 6 months after the operation)

Recheck the X-ray or CT to confirm complete healing of the fracture and assess whether the internal fixation needs to be removed (such as bone plates in non-load-bearing areas).

Second, selection of imaging examination methods

X-ray examination

Applicable scenarios: It is the preferred method for routine follow-up, with low cost and small radiation dose. It can quickly observe fracture alignment, callus formation and the position of internal fixation.

Key observation points:

Whether the fracture line is blurred or disappears;

Whether the bone plate is deformed, broken or the screws are loose;

Whether the articular surface is smooth (special attention should be paid to intra-articular fractures).

CT examination

Applicable scenarios: Complex fractures (such as intra-articular fractures and comminuted fractures) or when X-rays cannot make a clear judgment, CT can provide three-dimensional stereoscopic images to accurately assess fracture healing and internal fixation status.

Key observation points:

Minor displacement of the fracture end or nonunion of the bone;

Whether the screw penetrates the cortical bone or enters the joint cavity;

The fit between the bone plate and the bone surface.

MRI examination

Applicable scenarios: When soft tissue injuries (such as ligament and tendon injuries) or nonunion of bone combined with bone marrow edema are suspected, MRI can clearly display the changes in soft tissue structure and bone marrow signals.

Key observation points:

The range and degree of bone marrow edema

Swelling or injury of soft tissues.

Third, the core observation contents of imaging examinations

Fracture healing condition

Callus formation: Under X-ray or CT, an increase in callus around the fracture end can be seen, and the fracture line gradually becomes blurred.

Disappearance of the fracture line: At complete healing, the fracture line completely disappears and the continuity of the cortical bone is restored.

Nonunion of bone: If the fracture line remains clear more than 6 months after the operation and no callus formation occurs, the possibility of nonunion of bone should be considered.

Internal fixed state

Bone plate position: Observe whether the bone plate is deformed, displaced or broken, and whether the screws are loose, broken or penetrating the bone cortex.

Screw distribution: Whether the screws are evenly distributed at both ends of the fracture to avoid excessive concentration of screws causing stress concentration.

Internal fixation integrity: CT can clearly display the integrity of the bone plate and screws, eliminating minor fractures or deformations.

Complication assessment

Infection: If periosteal reactions, bone destruction or dead bone formation are observed on X-rays or CT scans, the possibility of infection should be taken seriously.

Refracture: Premature weight-bearing after surgery or failure of internal fixation may lead to refracture. Imaging examinations can clearly determine the location and degree of the fracture.

Joint degeneration: If the reduction is poor after intra-articular fracture surgery, it may lead to joint degeneration. MRI can assess the injury of articular cartilage and ligaments.

Fourth, imaging examinations and clinical decision-making

Assessment of fracture healing

If the imaging examination shows that the fracture line is blurred and the callus formation is good, the weight-bearing or the intensity of rehabilitation training can be gradually increased.

If the fracture line remains clear or the bone is not joined, the fixation time needs to be prolonged or a secondary surgical intervention should be adopted.

The timing for removing the internal fixation

Non-weight-bearing bone plates (such as the olecranon plate of the ulna) can be removed after the fracture has completely healed. Usually, an X-ray examination is required 1 to 2 years after the operation for confirmation.

If there is no obvious discomfort with the weight-bearing bone plates (such as the femoral bone plates), lifelong preservation can be considered, but regular imaging follow-up is required.

Complication management

If imaging examinations reveal infection, re-fracture or joint degeneration, the treatment plan should be adjusted promptly, such as anti-infection treatment, secondary surgery or joint replacement.

Fifth, precautions for imaging examinations

Radiation protection

Try to avoid frequent X-ray or CT examinations, especially for children and pregnant women. The method of examination should be decided after weighing the pros and cons.

Check the body position

During X-ray examination, it is necessary to maintain the correct body position to avoid overlapping of the fracture ends or internal fixation obstruction due to improper body position.

Dynamic observation

Imaging examinations should be dynamically evaluated in combination with the patient’s symptoms, signs and rehabilitation progress to avoid relying solely on imaging results.