Elimination of Na-131-I from the head and the neck of the femur in unaffected and osteoarthritic hip joints

Pathological aspects of osteoarthritis related to surgery

Careful examination of existing information may promote a greater understanding of the pathogenesis of osteoarthritis. Alterations in venous drainage of the juxta-articular bone appear to produce disturbances in the joint capsule microcirculation. Histological evidence suggests a slowing down of the circulation; this might be the cause of proliferation and thickening of the capsule, and may also explain the experimental findings of increased oxygen pressure within the joint caused by reduced utilization of oxygen and increased glycolysis within the joint capsule. This increased consumption of glucose may lead to a reduced glucose concentration in the synovial fluid. This causes a reduction of glycolysis in the joint-cartilage, followed by decreased lactate concentration in the synovial fluid. With the inducer of hyaluronic acid production (lactate) absent, the joint consequently 'dries up'. Furthermore, during times of increased wear, friction-products of articular cartilage can irritate the synovial membrane and cause effusion; this may explain an apparent contradiction. It is therefore necessary to discuss the effectiveness of preventive and curative surgery in osteoarthritis. The biological effect of juxta-articular osteotomies reaches beyond the purely mechanical consequences. The hypothesis that an improved circulation following osteotomy may affect the metabolic changes within the osteoarthritic joint is discussed.

Primary osteoarthritis of the hip. Interrelationship between intraosseous pressure, X-ray changes, clinical severity and bone density

The intraosseous pressure of the femoral head and greater trochanter was measured during 146 Charnley hip replacement operations. In 108 hips with primary osteoarthritis the pressure in the femoral head averaged 49.6 and in the greater trochanter 31.6 mmHg. The pressures in the greater trochanter were significantly lower than those in the femoral head. There was no sex difference, and the pressures were independent of age. The intraosseous pressure in the femoral head varied appreciably with a dispersion which did not significantly differ from the normal distribution. There was a faintly positive correlation between the mean blood pressure and the intraosseous pressure. No relationship was found between the pressure in the femoral head and the radiological severity of the osteoarthritis or between the intraosseous pressure and the duration of symptoms, severity of rest pain, walking ability, range of motion or degree of bone density at the site of measurement. The haemodynamic conditions in bone depend upon blood flow and resistance. Variations in these two factors determine the actual intraosseous pressure. As a consequence intraosseous pressure measurement as the only evaluation of the haemodynamic conditions is of limited value. The vascular factor in osteoarthritis needs further clarification.

Intramedullary pressure of the patella in Chondromalacia

Degenerative changes in load-bearing joints are often combined with altered intramedullary circulation. This may cause an alteration in intramedullary pressures. It has been said that articular symptoms are connected with a change in intramedullary pressures being high they are suspected to cause pain. In this investigation the intramedullary pressure has been evaluated in chondromalacia and osteoarthrosis of the patella. A comparison has been made with normal patellae. A biopsy needle was drilled into the intramedullary bone of the patella and connected with a registering unit. In a control group an average value of 19 mm Hg was registered. In the condromalacia group the mean intramedullary pressure was 44 mm Hg and in osteoarthrosis 37 mm Hg.

Intraosseous phlebography, intraosseous pressure measurements and 99mTC-polyphosphate scintigraphy in patients with various painful conditions in the hip and knee

Twenty-five patients with pain in the knee or hip were examined by means of bilateral intraosseous phlebography, intraosseous pressure measurements and 99mTechnetium polyphosphate scintigraphy. All patients with typical rest pain--either due to osteoarthritis or to the intraosseous engorgement-pain syndrome--showed venous stasis and increased pressure in the bone marrow near the painful joint and abnormally high uptake of the radiotracer. In patients with other types of pain this correlation was absent. The results indicate that 99mTechnetium polyphosphate scintigraphy can be used as a screening method in the diagnosis of the intraosseous engorgement-pain syndrome in patients with a typical history. However, increased isotope uptake in a joint region may be due to a variety of other causes. The identical findings with all three methods of investigation in patients with the intraosseous engorgement-pain syndrome and osteoarthritis suggest a common pathomechanism.

Radiologic signs of hip and knee joint degeneration. A potential source of iatrogenesis

Bilateral x-ray films of hip joints in 326 and knee joints in 193 asymptomatic patients were analyzed to investigate the prevalence of abnormalities. Degenerative changes, if any, were classified according to severity. Bilateral degeneration of hip or knee joints was found in 20% of the subjects. Thus, caution must be exercised in interpreting radiologic signs of joint degeneration in the absence of clinical evidence.

Experimental osteoarthritis in the rabbit knee joint

The development of arthrotic-like changes following the resection of the cruciate ligaments in the knee joint of rabbits has been studied at intervals from 2 weeks to 10 months in 35 animals. Signs of cartilage degeneration were followed by changes in the subchondral bone, where formation of osteophytes and condensation took place. An increased vascular supply was demonstrated by microangiographic and scintigraphic investigations. The uptake of 18F and 99mTc-polyphosphate reached a maximal value about 2 months after the operation and then diminished despite further development of arthrotic changes.

Intraosseous pressure in the femoral head and greater trochanter before and 1-3 years after osteotomy for osteoarthritis of the hip joint

To elucidate the long-term effect of osteotomy upon the intraosseous pressure in osteoarthritis of the hip, pressure measurements in the femoral head and greater trochanter were performed in 22 patients before intertrochanteric osteotomy and 11.5-33.5 months later, on the occasion of removing the osteosynthesis material after the osteotomy had healed. Preoperatively the mean pressure in the femoral head was higher (35.0 mmHg) than in the greater trochanter (23.4 mmHg). At follow-up the mean pressure in the femoral head had fallen, but not significantly (0.10 less than P less than 0.20). A significant reduction in pressure (0.001 less than P less than 0.005) was found in 10 patients in whom the primary pressure was high (exceeding 35 mmHg) and in 16 patients seen at follow-up less than two years after the osteotomy (0.01 less than P less than 0.02), whereas with a longer observation period there was a tendency towards an increasing pressure. The trochanteric pressures accompanied the pressures in the femoral head, but without significant changes. No close correlation was found between intraosseous pressure and pain at rest. The operation had a good clinical effect, especially upon the pain at rest. A reduction in intraosseous hypertension may be a contributory cause, but the tendency to another increase in pressure after a long observation period indicates the possibility of a subsequent recurrence.