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Diagnostic Examination of the Musculoskeletal System

10 min read

X-ray

An observation of bone density, texture, erosion, alignment, swelling, and intactness. The condition of joints (size of space, smoothness of articular cartilage, synovial swelling, irregularity, spur formation, narrowing) can be determined. Serial x-rays may be used for monitoring patient recovery.

  • Inform the client that the radiation exposure is low and not dangerous.
  • Remove all jewelry
  • Instruct the patient to remain still.
  • Determine if the patient is pregnant: if so, a protective shield may be work over areas not being scanned (abdomen, ovaries, etc.)

Computed Tomography Scan

A CT scan with or without contrast agents (oral or IV), producing a more detailed cross-sectional image o the body. These can be used to visualize and assess tumors; injuries to soft tissue, ligaments, or tendons; and severe trauma to the chest, abdomen, pelvis, head, or spinal cord. It is used to identify the location and extent of fractures in areas that are difficulty to evaluate (e.g. the acetabulum) and not visible on x-rays.

Magnetic Resonance Imaging

An MRI is a non-invasive imaging technique that uses magnetic fields and radio waves to create high-resolution pictures of bones and soft tissues. It can be used to visualize and assess torn muscles, ligaments, and cartilage; herniated discs; and a variety of help or pelvic conditions.

  • The MRI scanner is noisy and may take 30 to 90 minutes to complete the test. Inform the patient to remain as still as possible.
  • A powerful electromagnet is used, and such is disallowed for patients with metal implants. All metal-containing items are removed as they may cause burns or be damaged. This includes things like credit cards and transdermal patches with aluminized backing.
  • If IV contrasts are used, a consent form is required.
  • If claustrophobia is an issue with MRI machines, there are open-type MRI machines, but they utilize lower-intensity magnetic fields and thus produce a lower-quality image. They are also quieter.

Bone Scan/Nuclear Scan/Scintigraphy

A radiotracer is injected into the vein, and emits gamma radiation as it decays. A gamma camera scans the areas that absorb the tracer and creates an image of cold and hotspots. Scans can detect problems days to months earlier than a regular X-ray (e.g. a stress fracture may be detected despite no findings in a standard x-ray). These scans are done to evaluate damage to the bones, detect metastatic cancer, and monitor conditions that can affect the bone e.g. infection (aseptic osteomyelitis) and trauma.

  1. Cold Spots: little or no tracer absorbed in an area makes it appear dark, which may indicate a lack of blood supply to the bone (bone infarction) or some types of cancer.
  2. Hot Spots: increased tracer absorption may show areas of increased metabolism; rapid bone growth or repair. These appear bright, and can indicate the presence of a tumor (osteosarcoma), a fracture, or an infection (inflammatory skeletal disease; osteomyelitis).

Nursing Considerations

  • Before:
    • Due to the use of a contrast, a consent form is required.
    • Inform the physician if the patient is pregnant.
    • Determine any potential allergies to the contrast.
    • Inform the patient of indications, procedure, and provide reassurance that the radionuclide poses no radioactive threat.
    • Limit fluids for up to 4 hours before the test, as extra fluids will be prescribed after injection of the radiotracer to excrete excess radioactive substances into urine. Empty the bladder before the scan to remove obstruction of the pelvic bones by the radioactive urine.
  • During:
    • Feelings of flushing and warmth are expected.
    • The patient may need to wait for 1 to 3 hours after injection, so a diversional activity may be required e.g. a book or audiotape.
    • Depending on the area being scanned, the patient may need to remove clothing. All jewelries should be removed.
  • After:
    • The injection site might be sore or swelling may develop; relieve by applying moist, warm compresses to the arm.
    • Encourage the client to increase fluid intake the facilitate urinary excretion of the isotope. It should be excreted within 48 hours; the excretions are not harmful to others.

Bone Densinometry

Evaluation of an individual’s BMD, performed through X-rays or Ultrasound. The most common modality involves the use of Dual-Energy X-ray Absorptiometry (DEXA), Quantitative Computed Tomography (QCT), and quantitative ultrasound (QUS).

  • DEXA measures BMD and predicts fracture risk through accurate monitoring of bone density changes in patients with osteoporosis who are undergoing treatment. It is the recommended diagnostic and monitoring method for osteoporosis. This measures the density of bones in the spine, hip, and wrist. A peripheral form (pDXA) may measure forearm, finger, or heel BMDs but is less accurate in projecting hip or spine fracture risk. The best bone site for monitoring osteoporosis with DEXA is the hip or spine.

Bone Biopsy

A biopsy is often done to tell the difference between cancerous and non-cancerous bone tumors and to identify other bone problems.

  1. Closed Bone Biopsy: a bone biopsy inserts a needly through the skin and directly into the bone (via needle or drill biopsy) to obtain a sample.
    • A local anesthetic, IV pain medication, and sedatives may be given to reduce pain and anxiety.
    • There are no special preparation for a closed bone biopsy; the patient signs a consent form and wears a hospital gown.
    • If sedatives are used, the patient may stay longer and have someone drive them home.
  2. Open Bone Biopsy: an incision exposes an area of the bone, where a sample is obtained.
    • General Anesthesia may be required for upper body biopsies; lower body biopsies may only require spinal anesthesia or nerve blocks.
    • NPO 8 to 12 hours before the procedure. Normal diet may be resumed after procedure. An overnight stay in the hospital may be required.
  3. Post-biopsy: a bandage is placed over the site. Keep it covered and elevated for 24 to 48 hours.
    • Ice packs can prevent hematoma formation.
    • Monitor for redness, edema, bleeding, and pain.

Muscle Biopsy

A sample of the muscle may be obtained to identify or detect muscular disorders (muscular dystrophy, congenital myopathy), metabolic defects of the muscle, infections of the muscle, and differentiation between nerve and muscle disorders. More than one needle insertion may be needed to get an adequate sample.

  • No fasting or other special preparations are usually necessary for a closed muscle biopsy. Management is the same as after a bone biopsy.

Electromyography (EMG)

A measurement of the electrical potential of skeletal muscles and the nerves leading up to them. A needle electrode is inserted into the muscle, and the patient is instructed to contract and relax the muscle multiple times. This is performed to evaluate muscle weakness, pain, and disability. These differentiate muscle and nerve problems, and determine abnormalities in functioning.

  • If nerve function does not return within 4 months of injury, an EMG may be used to determine the extent of damage.
  • An EMG is contraindicated in patients taking anticoagulant medications and any active skin infection, as the electrode may cause bleeding or infection within the muscle.
  • A consent form is required. Avoid using any creams or lotions on the day of the test. No other special preparations are required.
  • Afterwards, muscles may feel tender, bruised, or sore for a few days. Encourage rest and warm compresses.

Arthrogram/Arthrography

A contrast material or air is injected to study the joint space via an x-ray. This is used for any unexplained joint pain and progression of joint disease. These study the joint structures e.g. tendons, ligaments, cartilage, and the joint capsule. The joint is moved through its full range of motion to distribute the contrast agents. Any tears will produce visible leakage in the final image.

  • Notify the physician if the patient is pregnant.
  • Remove jewelries
  • Activities can be resumed immediately after the procedure.
  • A compression elastic bandage is often prescribed. The joint is usually rested for 12 hours and strenuous activity prohibited until approved by the primary provider. Inform the patient that crackling and clicking in the joint for 24 to 48 hours is normal (the contrast agent or air have not been absorbed)
  • Mild analgesia, ice, and other additional comfort measures may be provided by the nurse.

Arthroscopy

Instrument/s are inserted into the joint (viewing scope, irrigating instrument, trimming instrument, etc.) to directly visualize (for diagnosis) or perform a surgical procedure (removal of loose bodies, assessment of abnormal articular cartilage) on a joint. It is an endoscopic examination of various joints done under GA or local anesthesia.

  • A consent form is required.
  • NPO for 8 to 12 hours before the procedure.
  • Joint areas may require shaving.
  • A sedative is given.
  • A hospital gown should be worn.
  • Afterwards, limit activity for 1 to 4 days. Walking without weight bearing is often permitted. A compression elastic wrap is worn for 2 to 4 days to control swelling. Elevate the extremity and place ice on the site. (Basically the RICE interventions).

Arthrocentesis

A closed joint aspiration of synovial fluid via a needle for diagnostic examination or direct relief from joint effusion. This is useful for septic arthritis and other inflammatory arthropathies or hemarthrosis. Synovial fluid is normally clear, pale, straw colored, and scanty in volume.

  • Diagnosis of specific types of arthritis (rheumatoid arthritis)
  • Check for crystals in the joint fluid, potentially a sign of gouty arthritis
  • Reveals the presence of hemarthrosis (bleeding into the joint cavity), a sign of trauma or hemophilic disorders.
  • Verify the presence of an infection, identify causative agents, and monitor progress of antibiotic therapy.
  • Medications may also be directly injected into the joint space.

A consent form is required for the procedure.

  • Shaving may be required. Antispasmodics may be given to alleviate discomfort during the procedure.
  • Afterwards, a compression bandage applied is used. Rest the joint for 8 to 24 hours. Ice may be prescribed for 1 to 2 days post-procedure to diminish edema formation and pain.
  • Take acetaminophen, ibuprofen, or some other mild pain killer for a day or two after the procedure.
  • Instruct the client to notify the physician if any complications (fever, excessive bleeding, swelling, numbness, cool skin) occur.

Allergy Testing

For any test requiring contrast agents to be used, screen the patient for allergies.

Laboratory Studies

Studies of the patient’s blood and urine can identify the presence and amount of chemicals and other substances. The results may indicate a primary musculoskeletal problem (e.g. Paget’s disease of the bone), a developing complication (e.g. infection), the baseline for instituting therapy (e.g. anticoagulant therapy) or response to therapy and possible causes of bone loss.

  • Coagulation studies are performed to detect bleeding tendencies before surgery.
  • Serum Calcium Levels are altered in patients with osteomalacia, parathyroid disorders, paget’s disease, metastatic bone tumors, or prolonged immobilization.
  • Serum Phosphorus Levels are inversely related to calcium levels and are diminished in osteomalacia associated with malabsorption syndrome.
  • Acid Phosphatase Levels are elevated in Paget’s disease and metastatic cancer.
  • Alkaline Phosphatase Levels are elevated during early fracture healing and in diseases with increased osteoblastic activity (e.g. metastatic bone tumors).
  • Thyroid Studies and determination of Calcitonin, PTH, and Vit. D is used for evaluation of bone metabolism.
  • Serum Enzyme Levels of Creatine Kinase and Aspartate Aminotransferase elevate in muscle damage.
  • Serum Osteocalcin indicates the rate of bone turnover.
  • Urine Calcium Levels increase with bone destruction (e.g. in parathyroid dysfunction, metastatic bone tumors, multiple myeloma).
  • Bone resorption may be evaluated with specific urine and serum biochemical markers (N-telopeptide type 1 collagen [NTx], deoxypyridinoline [Dpd]).
  • Elevated levels of bone-specific ALP, osteocalcin, and intact N-terminal propeptide of type 1 collagen (P1NP) reflect increased bone remodeling activity.

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