Villous pigment nodule synovitis

　　The etiology of villous pigment nodular synovitis is unknown. Some researchers believe that this disease is an inflammatory reaction, while others believe it is a tumor. The disease may be a synovial disease between inflammation and benign tumor. The villous type is more similar to inflammation. Animal experiments have shown that repeated injections of blood into the joint cavity can produce pathological changes similar to those of the villous type. Athletes may also develop similar changes due to multiple knee joint bleeding. The nodular type is composed of a large number of synovial cells. Recurrence is easy if the resection is not thorough. Therefore, it is similar to a benign tumor.

　　Villous pigment nodular synovitis is an idiopathic proliferative lesion involving the synovium, joint capsule, and tendon sheath, which can be focal or diffuse. It is most common in the knee joint, followed by the hip joint. When the knee joint of young patients is involved, the entire synovium is involved, the intercondylar eminence of the tibia is eroded, and subchondral granuloma can be seen at this time, with a diameter of 3mm, similar to giant cell tumor of the tibia. The bone cortex of the femoral condyle can be seen to be destroyed in the section view. Due to the large amount of synovial tissue proliferation, the joint pressure increases, the villi are prone to penetrate through the joint cartilage, the junction of bone and joint, or along the ligament attachment site to invade the cancellous bone. Bone tissue invasion is more common in the hip, ankle, and knee joints. Because the joint capsule cavity is large in the knee joint, the bone tissue is not easily compressed, and bone destruction is relatively rare.

　　Villous pigment nodular synovitis does not have obvious systemic symptoms, the body temperature of the patient is not high, the erythrocyte sedimentation rate is not fast, and there is no change in the blood picture. Local symptoms are also mild in the early stage, so patients seek medical attention late, the disease course is long, and the most common disease course is 1 to 5 years, more than half of whom have a history of trauma. The main symptoms are joint swelling, and pain is usually mild. The local skin temperature is sometimes slightly higher, joint function is limited, and the joint presenting with diffuse swelling feels spongy when touched, and palpable fluctuation can be felt in the case of large effusion. Sometimes, nodules of different sizes that can be slightly moved can be felt.

　　When the knee joint is involved, the prepatellar bursa and patella become明显ly swollen, the patellar test is positive due to a large amount of effusion, the proliferative synovial tissue can sometimes break through the posterior joint capsule and enter the popliteal fossa, and then spread downward along the muscle gaps on the back of the lower leg, causing deep-seated diffuse swelling. In patients with affected ankle joints, the swelling is most obvious around the medial and lateral malleoli. When the hip joint is involved, the swelling is mostly located in front of the hip joint.

　　Whether diffuse or limited, the affected limb has mild muscle atrophy, joint aspiration can extract bloodstained or coffee-colored fluid, this synovial fluid is very special and has diagnostic value.

　　Villous pigment nodule synovitis is relatively rare, with two types: villous type and nodule type. Patients are mostly young and middle-aged males, with ages mostly between 20 to 40 years old. This disease often occurs in the knee and ankle joints, followed by the hip, tarsal, wrist, and elbow joints, and occasionally in bursae and tendons. The surgical treatment of this disease has a good effect, and active prevention is better than treatment. The following are the preventive measures for pigment villous nodule synovitis.

　　1. Avoid long-term intense exercise:

　　Long-term, excessive, and intense exercise or activity is one of the basic causes of synovial degeneration. Especially for weight-bearing joints (such as the knee and hip joints), excessive exercise increases the force on the joint surface and exacerbates wear. Long-term intense exercise can also cause excessive stress and traction on the bones and surrounding soft tissues, resulting in local soft tissue injury and uneven stress on the bones, thus leading to bone hyperplasia.

　　2. Engage in appropriate physical exercise:

　　Avoiding long-term intense exercise is not about inactivity, but rather, appropriate physical exercise is one of the good methods to prevent osteoarthritis.

　　3. Timely treatment of joint injuries:

　　Joint injury includes soft tissue injury and bone injury. Osteoarthritis of the joint is often directly related to intra-articular fractures. Due to incomplete reduction of fractures, the joint cartilage surface becomes uneven, thus causing traumatic arthritis. For patients with intra-articular fractures, if treated in time and achieved anatomical reduction, it is completely possible to avoid the occurrence of traumatic arthritis and joint hyperplasia.

　　4. Weight loss:

　　Excess weight is one of the important causes of spinal and joint bone hyperplasia. Excess weight accelerates the wear of joint cartilage, making the pressure on the joint cartilage surface uneven.

　　The above are the preventive measures for villous pigment nodule synovitis. Active prevention can reduce the chance of getting the disease and is beneficial to health. Prevention should start from daily life.

　　Villous pigment nodule synovitis is relatively rare, with two types: villous type and nodule type. Patients are mostly young and middle-aged males, with ages mostly between 20 to 40 years old. This disease often occurs in the knee and ankle joints, followed by the hip, tarsal, wrist, and elbow joints, and occasionally in bursae and tendons. Diagnosis of this disease requires examination, and the following are the main examination methods for this disease:

　　I. Laboratory tests required for villous pigment nodule synovitis:

　　1. Routine blood tests, erythrocyte sedimentation rate, rheumatoid factor, and C-reactive protein tests show no significant changes.

　　2. Joint puncture for fluid extraction: The joint fluid is mostly bloody, but can also be orange-yellow.

　　II. Other auxiliary examinations:

　　1. X-ray

　　The X-ray signs of this disease include joint swelling and erosion and destruction of joint bones, with soft tissue swelling presenting as nodules with high density. PVNS bone erosion often starts at the junction of bone and cartilage, so the joint space generally remains normal, but it can widen when there is a large amount of joint effusion; the joint space can become narrow when secondary joint degeneration or significant erosion of joint cartilage occurs.

　　2. CT

　　It is a cross-sectional imaging method with high density resolution, which is significantly superior to X-ray films in displaying soft tissue masses within the joint cavity, joint effusion, and bone erosion. It is also more sensitive than X-ray films in displaying the hardening margin around bone defects. CT enhancement scanning can display irregularly thickened synovium, which can help in the diagnosis of PVNS. However, CT lacks specificity in displaying lesions of the joint capsule, cartilage, soft tissue, etc., and is only of great significance when there is obvious bone erosion. Therefore, the diagnostic value of CT is limited in the early stage of PVNS or when bone erosion has not occurred.

　　3. MRI

　　High tissue resolution can display the entire morphology, type, and tissue composition of the lesion. The typical manifestations of PVNS are T1WI and T2WI showing low signal. The pathological basis of this characteristic is the deposition of hemosiderin in the nodules. However, in the early stage of the lesion, only bleeding is present within the joint, and there is little or no hemosiderin deposition in the nodules. In the late stage, hemosiderin is absorbed and transported, resulting in a decrease. Therefore, this signal characteristic does not run through the entire process of the lesion.

　　4. Laboratory examination

　　Under the microscope, the surface of the papillae is composed of several layers of synovial cells, with a small amount of fibrous tissue at the center, dilated capillaries, and a small number of inflammatory cells. Iron-containing hemosiderin granules can be seen inside and outside the cells. The nodules are composed of dense synovial cells, with little cytoplasm, unclear cell membranes, and deeply stained nuclei. Cracks and papillae can be seen in the dense cells, and multinucleated giant cells and foam cells are occasionally seen between synovial cells.

　　The above are the examinations for verrucous papillary synovitis, through which it can be determined whether a patient has verrucous papillary synovitis. If diagnosed with the disease, surgical treatment is recommended.

　　Verrucous papillary synovitis is relatively rare, and the disease often occurs in the knee and ankle joints, followed by the hip, subtalar, wrist, and elbow joints, and occasionally in bursae and tendons. The main treatment for this disease is surgery and radiation therapy. The following is an introduction to the dietary recommendations and禁忌 for patients with verrucous papillary synovitis:

　　1. It is recommended to reduce the intake of dairy products such as milk and goat milk, as well as foods containing tyrosine, phenylalanine, and tryptophan such as peanuts, chocolate, millet, cheese, and sugar, as they can produce prostaglandins, leukotrienes, tyrosine kinase autoantibodies, and anti-milk IgE antibodies that can cause arthritis, leading to allergies and exacerbation, recurrence, or deterioration of the disease.

　　2. Reducing the intake of fatty meats, high animal fats, and high cholesterol foods is advisable, as the ketone bodies, acids, arachidonic acid metabolites, and inflammatory mediators they produce can suppress the function of T lymphocytes, and are prone to cause and worsen joint pain, swelling, bone decalcification, and joint destruction.

　　3. Reducing the intake of sweets is recommended, as the sugars are prone to cause allergies and can worsen the progression of the disease, leading to increased joint swelling and pain.

　　4. Reducing alcohol and coffee, tea, and other beverages is also a key to health regulation, and attention should be paid to avoiding passive smoking, as all of them can exacerbate disease progression.

　　5. It is advisable to eat more animal blood, eggs, fish, shrimp, bean products, potatoes, beef, chicken, and cow's 'tendon' meat, which are rich in histidine, arginine, nucleic acids, and collagen.

　　The above are the dietary taboos for patients with pigmented verrucous nodular synovitis. Scientific and reasonable diet is conducive to the recovery of the disease and can shorten the recovery time.

　　Pigmented verrucous nodular synovitis is relatively rare, with two types: verrucous type and nodular type. Patients are mostly young and middle-aged males, with ages mostly between 20 to 40 years old. The disease often occurs in the knee and ankle joints, followed by the hip, tarsal, wrist, and elbow joints, and occasionally seen in bursae and tendons. The treatment of this diseaseThe main treatments are surgery and radiotherapy. The following introduces the treatment methods for verrucous nodular synovitis..

　　1. Surgical resection is relatively complete.

　　It is particularly suitable for nodular cases. Radiotherapy is better for verrucous type. It is not effective for nodular type. For diffuse lesions, all synovial tissue should be removed to avoid recurrence. For knee joint lesions with abundant synovium that are not easy to completely remove, the synovial tissue in front and behind the joint should be cut as much as possible first. Surgical resection is the treatment for verrucous nodular synovitis. Due to the difficulty of complete resection, recurrence is common. Arthroscopic synovectomy is suitable for inactive nodular or diffuse types. Open synovectomy is suitable for patients with active diffuse verrucous nodular synovitis. Total knee replacement is suitable for PVNS with destructive changes in the joint.

　　2. Radiotherapy is performed again after surgery.

　　It can also achieve the purpose of cure. For diffuse nodular lesions of the knee joint, the cruciate ligament and collateral ligament should be cut. After the joint is dislocated, the synovial tissue in front and behind the joint should be completely removed. If the nodular lesions are not completely removed, recurrence is likely. Moreover, a few cases may transform into synovial sarcoma. For localized lesions, only the local synovial tissue needs to be removed.

　　The above are the treatment methods for pigmented verrucous nodular synovitis, and the current effectiveness of these two methods in treating the disease is good.