Haemarthrosis of the Knee

Hemarthrosis is blood inside the knee or bleeding into the knee joint space. The swelling and fluid inside the knee joint is usually relieved with an aspiration. During the aspiration, the physician will insert the needle on the lateral side of the knee, just above the upper border of the patella. The needle enters below the patella into the suprapatellar bursa which is continuous with the joint cavity. This aspiration technique is different than how physicians perform injections. For a knee injection, the needle is inserted at the lower border of the patella on either side of the patellar tendon at the soft spot.

aspiration v inspirationThe color of the fluid aspirated—not bloody effusion—is probably due to synovial irritation caused by chronic processes such as gout, pseudogout, arthritis, rheumatoid arthritis, or degenerative meniscus. A degenerated meniscus may be associated with swelling and fluid collection; usually not bloody. The peripheral portion of the meniscus is vascular (about 3-5 mm). The blood supply of the meniscus originates from the medial and lateral genicular arteries. Although a degenerative meniscus effusion is not bloody, a traumatic tear of the meniscus may cause bleeding inside the knee joint.

arthrA bloody effusion could be trauma related or non-trauma related. For example, hemarthrosis can be caused by trauma or injury to the structures of the knee such as the ACL, PCL, or meniscus. Hemarthrosis can also occur due to tibial plateau fractures, chondral fractures, patellar dislocations, or a meniscal tear. Non-traumatic conditions that can cause hemarthrosis include: PVNS, sickle cell anemia, hemophilia, anticoagulation, or hemorrhage following total knee replacement.

Hemoarthrosis from trauma or injury indicates a significant knee injury such as ACL (75-80%) or a meniscal tear. If aspirations of the knee after trauma shows hemarthrosis, early evaluation of the injury may be necessary to define the extent of damage. The physician may get an MRI early.

meniscusAbsence of hemarthrosis does not mean a less severe ligament injury—the blood may escape without distending the capsule. A severe injury may cause minimal or severe joint effusion. More than 20cc of fluid may affect the quadriceps function and prevent full extension of the knee. A hematoma should be evacuated. The bloody aspirate should be examined for fat to rule out a fracture. The aspirate may vary in color depending on the severity of the injury and the duration of the symptoms. Fat is less dense than blood and fat floats on the surface, whereas blood is heavier and stays on the bottom.

mri.The presence of a fat/fluid level is diagnostic of a fracture even if a fracture is not seen on an x-ray (occult). Fat/fluid level is usually seen with tibial plateau, chondral, and patellar fractures. The cross table lateral view of the knee shows it well. When a fat/fluid level is seen, look for intra-articular fractures. Lipohemarthrosis is only seen on horizontal x-ray beams with the beam parallel to the floor. It occurs in 40% of all fractures inside the joint.

lipohemoarthrosis

Advertisements

Osteoporosis

Osteoporosis is a decrease in bone strength. The strength of the bone depends on mineral density and bone quality. Osteoporotic bone is at risk of fracture at the hip, wrist and spine.

osteoporosis1.png

If fracture of the vertebral spine occurs, the patient will have a fivefold increased risk for having a second vertebral fracture or hip fracture. A second vertebral fracture means you may have more compression fractures in the future.

With one hip fracture, there will be a tenfold increase of another hip fracture occurring. Men with hip fractures have a higher mortality rate than women.

Lifetime risk of fractures of the hip, spine and wrist is 40 %. The decrease of bone strength and bone mass clearly predicts fracture risk.

osteoporosis2.png

Osteoporosis affects 45% of women aged 50 or older. There is some correlation between osteoporotic fracture and risk of death. This is logical since 25% of patients with hip fracture die within one year. The lifetime risk is high with senile osteoporosis. There are about million osteoporosis related fractures that occur per year.

Men and women both begin to start “spending” or losing bone at a certain point in their lives. Banking or building up of bone during youth has benefits during the later years. Most individuals obtain their peak bone mass between ages of 16 and 25 years. Men begin to lose bone mass after the age of 25 years at a rate of 0.3% per year. Women begin to lose bone at a rate of 0.5% per year. After menopause there is an accelerated rate of bone loss at the rate of 2-3% of total bone loss per year for about 10 years.

osteoporosis3.png

Osteoporosis has bone mineralization but abnormal osteoclast function. There are two types of osteoporosis:

  1. Type I: postmenopausal which occurs 15-20 years after menopause. It has increased risk of vertebral and wrist fractures. It is due to estrogen deficiency.
  2. Type II: senile which occurs in men and women over the age of 70 years. Vertebral and hip fractures are a risk. It occurs more in females than males with a ratio 2:1. It is due to aging and long term calcium deficiency.

20-25% of elderly patients could die within one year suffering of a hip fracture.

osteoporosis4.pngRisk factors for osteoporosis include: thin, north European descent, people who live sedentary lifestyles, smoker and drinkers, and anti-seizure medications as phenytoin (Dilantin) and phenobarbital.

The bone mineral density is measured by T- score which is relative to normal age, young, matched control (25 year old women) and Z-score which is relative to similar aged patients.

How is osteoporosis measured? It is measured by DEXA scan at the hip through the T –score. DEXA scan is important in predicting fracture risk.osteoporosis5.png

Lab findings as albumin, calcium, phosphate, vitamin D, parathyroid hormone and bone specific alkaline phosphatase are usually normal.

Vitamin D levels are low in about 70 % of patients with fracture. Vitamin D absorbs calcium from the intestines. With aging, the stomach acidity decreases and the calcium absorption decreases and vitamin D requirements increase. Elderly need more vitamins D to absorb the same amount of calcium.

Treatment of osteoporosis include: bisphosphonates, Denosumab and calcitonin. Bone stimulation can be achieved by parathyroid hormone, calcium and vitamin D.

When to initiate therapy? If T-score is less than -2 with no risk factors, if T-score is less than -1.5 with at least one risk factor as prior vertebral fracture or hip fracture.

What decides if you develop osteoporosis or not? Your savings: you can control this by adding more bone when you are young before the age of 25 years. You begin spending your bone after 25 years.

What is Rheumatoid Arthritis?

Rheumatoid arthritis involves the synovium of the joints. The condition of rheumatoid arthritis will result in deformities. Rheumatoid arthritis occurs in females more than males.

rheumatoid1.png

There may be a hereditary component with rheumatoid arthritis. Rheumatoid arthritis has spontaneous remissions and exacerbations. The disease can have a systemic nature. Pain and stiffness of joints especially in the morning (morning stiffness). Rheumatoid arthritis is typically poly-articular, bilateral, and symmetrical and most commonly affects the hands and feet.

rheumatoid2.png

X-rays show periarticular erosions at the time of diagnosis. Osteopenia and minimal osteophyte formation favors the diagnosis of rheumatoid arthritis.

Pathogenesis

Rheumatoid is an auto immune disease. The disease has two important components: immunological reactions and increased degradative enzymes. The IgM (rheumatoid factor) is produced by the plasma cell as an antibody to the native IgG, which is altered in RA. 70% of the patients with RA have rheumatoid factor positive. Leukocytes are attracted to the immune complex forming deposits over the inflammatory surface of the synovium. These leukocytes ingest fibrin and immune complex and is called the rheumatoid cells. The leukocytes release lysosomal enzymes that causes acute inflammatory response and tissue necrosis as well as inflammatory mediators (IL-1, IL-6, and TNFα). The chondrocytes respond to stimulation by TNFα, IL-1 and other inflammatory mediators causing cells to become activated and secrete more metalloproteinases which lead to cartilage damage. The synovium becomes hypertrophied (Pannus), showing intimal hyperplasis and infiltration by plasma cells and lymphocytes.

rheumatoid3.png

Stages of Rheumatoid Arthritis

Early stages (acute) include hot, swollen, tender joints (synovitis), wrist swelling, MCP swelling and Flexor Sheath Synovitis. Complicated rheumatoid arthritis include digital vasculitis, ecchymosis, skin atrophy and nodules. Advanced rheumatoid arthritis includes swelling of the MCP joints, lateral slippage of extensor tendons and tendon ruptures and ulnar deviation of fingers. X-rays show destruction of MCP with subluxation, ulnar deviation and wrist destruction.

Finger deformities include mallet, boutonniere, and swan neck.

rheumatoid4.png

The thumb is also involved. These changes occur due to proliferation, inflammation and hypertrophy of the synovium. Involvement of the distal radioulnar joint is usually associated with rupture of the extensor digiti minimi.

rheumatoid5.png

Rheumatoid Nodules

25% of patients with RA will have subcutaneous nodules on extensor surfaces of elbow and forearm. Nodules are often multiple and seen along the ulnar margin of the forearm or pulp of the digits. Vasculitis is more common in patients with SC nodules, it is a strongly seropositive disease (aggressive) with a less than favorable prognosis.

rheumatoid6.png

Treatment

If the patient has synovitis, it should be treated by a splint and medical treatment. If the patient has joint space narrowing, bone erosions and osteopenia the patient will need a synovectomy. If the patient has joint destruction/fixed deformity or loss of hand function, surgery is based on the conditions.

Before operating on RA patients, x-ray of the cervical spine is needed because the patient may have subluxation of C1-C2. Metacarpophalangeal joint arthroplasty of the fingers usually results in decreased extensor lag and improvement of the ulnar drift.

Common Conditions of the Thumb

Many different conditions can affect the normal function of the thumb (Figure 1). It is important to recognize the most common conditions so appropriate treatment can be given.

thumb1.PNG

Stenosing Tenosynovitis (Trigger thumb) (Figure 2)

One of the more common abnormalities of the hand associated with painful triggering or locking of the thumb is stenosing tenosynovitis. When the patient tries to straighten the thumb, the nodule jams beneath the pulley proximally.

thumb2.PNG

Extensor Pollicis Longus Tendon Rupture (Figure 3)

The EPL tendon is responsible for extension of the thumb’s distal interphalangeal joint. When a rupture occurs, the patient will experience loss of thumb extension and this typically occurs due to fracture of the distal radius. Rupture of this tendon prevents the extension of the distal phalanx.

thumb3

Entrapment of the Posterior Interosseous Branch of the Radial Nerve (Figure 4)

The posterior interosseous nerve is a continuation from the radial nerve and runs through the forearm. The nerve passes through the supinator muscle of the forearm, found on the outside of the elbow. The nerve becomes entrapped at the proximal edge of the supinator. Injury of the nerve may also be associated with fractures or dislocations of the radial head or the elbow joint. The patient will be able to perform wrist extension but not finger extension.thumb4.PNG

Unable to do the OK Sign (Figure 5)

The anterior interosseous nerve branches from the median nerve just below the elbow and supplies the deep muscles on the front of the forearm. Typically, there will be weakness of the long flexor muscles of the thumb (Flexor Pollicis Longus) and the deep flexor muscles of the index and middle fingers.

thumb5.PNG

Injury to the Ulnar Nerve (Froment’s Sign) (Figure 6)

Cubital tunnel syndrome occurs due to compression of the ulnar nerve at the elbow. As a result of cubital tunnel syndrome, the patient is unable to cross or abduct the fingers. When pinching a piece of paper between the thumb and index finger, the thumb IP joint will flex if the adductor pollicis muscle is weak.

thumb6.PNG

Rheumatoid Arthritis of the Thumb (Figure 7)

Rheumatoid arthritis is inflammation or irritation causing pain, swelling, weakness, and overtime, loss of the normal shape and alignment of the joint. This deformity can lead to the loss of the ability to grip, grasp, and pinch.

thumb7.PNG