Applicable evidence of arthrocentesis
1.The fluid accumulation in the joint cavity of the extremities must be examined by puncture or drainage, or treated by injection of drugs.
2.Injecting air or contrast into the joint cavity and performing arthrography to understand the changes in the cartilage or bone ends of the joint.
Drug indications
It is applicable to the auxiliary treatment of deformed knee arthropathy and shoulder periarthritis.
For patients with advanced OA, where the joint surface is severely worn and the joint space has disappeared, the best method is to perform artificial knee joint replacement.
Mechanism of action of sodium vitrate injection
Some scholars have analyzed the synovial fluid of the affected joints in patients with osteoarthritis and found that the concentration and molecular weight of vitreous acid in the synovial fluid are lower than normal, and the synovial membrane has a low function of synthesizing vitreous acid, which weakens the support and stabilization of synovial cells and collagen fiber scaffold, and impairs the biological function of lubrication and resistance to mechanical force, thus increasing the stress on the articular cartilage and causing damage to cartilage cells.
Pathological changes and causes of osteoarthritis of the knee: The pathological changes of osteoarthritis of the knee are mainly limited, progressive destruction of articular cartilage and formation of bony redundancies at the joint edges. The causes of these changes are: ① Injury: disturbance of load conduction is the main cause of cartilage damage. In particular, the increased load directly damages the cartilage cells and increases the pressure in the joint cavity, which affects the secretion of synovial fluid and reduces the nutrients available to the chondrocytes, thus aggravating the destruction of the chondrocytes. ②Chondral degeneration is related to autoimmunity. (3) Oxygen free radicals reduce the secretion of hyaluronic acid and degrade hyaluronic acid molecules, causing a decrease in the viscosity of synovial fluid.
The most commonly used drugs in clinical practice are non-steroidal anti-inflammatory analgesics (NSAIDs) and hormones. Both of these drugs have different degrees of adverse effects, and most of them can only provide short-term relief, but not stop the progression of the disease. The injection of high molecular weight, high concentration and high viscoelasticity of sodium vitrate into the joint cavity can significantly improve the inflammatory reaction of synovial tissue, increase the content of sodium vitrate in synovial fluid, compensate for the low quality of hyaluronic acid, enhance the viscosity and lubricating function of joint fluid, and also promote the production of high molecular weight hyaluronic acid by synovial cells in the joint, which provides high quality raw material for cartilage repair and promotes the healing of joint cartilage. It also promotes the healing and regeneration of articular cartilage, hinders and delays the degeneration of articular cartilage, prevents the formation of fibrous tissue in the joints, and supports the healing process of cartilage and synovial tissue. The effect is to relieve pain and increase joint mobility.
The principle of action of sodium vitrate: sodium vitrate is the main component of synovial fluid and is one of the components of cartilage matrix. It acts as a lubricant in the joint cavity to reduce friction between tissues, and also plays an elastic role to cushion the damage to joint cartilage from stress. The injection of high molecular weight, high concentration and high elasticity of sodium vitrate into the joint cavity can significantly improve the inflammatory response of synovial fluid tissue, enhance the viscosity and lubricating function of joint fluid, protect joint cartilage, promote the healing and regeneration of joint cartilage, relieve pain and increase joint mobility. Sodium vitrate molecules have a stabilizing effect on joint pain receptors, while its barrier effect can effectively prevent the diffusion of inflammatory mediators and reduce the stimulation of chemical substances on nociceptive receptors. The protective effect of joint pain is achieved. It is also believed that exogenous hyaluronic acid concentration up to 20mg/ml can make synovial B cells produce endogenous hyaluronic acid through negative feedback mechanism, which can re-form bright plate like structure on the damaged articular cartilage surface to protect articular cartilage and prevent further damage, This allows for the normal metabolism of articular cartilage and thus the treatment of osteoarthritis.
In the 1960s, viscoelastic filling therapy was proposed to restore the elasticity and viscosity of synovial fluid by injecting hyaluronic acid into the diseased joint cavity to re-establish the protective effect of hyaluronic acid on articular cartilage, alleviate synovial inflammation, reduce cartilage destruction and improve clinical symptoms. Hyaluronic acid also plays an important role in the formation of cartilage matrix through the aggregation of proteoglycans. Hyaluronic acid for medical use is purified from chicken crowns and has recently been reported to be effective and safe for pain relief. It should be noted that sodium hyaluronate is suitable for the treatment of early and mild osteoarthritis, while it is less effective in people over 50 years of age, with a disease duration of more than 1 year, obesity, severe joint effusion and X-rays showing advanced hyperplasia and degeneration.
Sodium hyaluronate is a common drug for the clinical treatment of OA, and its effectiveness has been confirmed. Sodium hyaluronate is widely present in human tissues, especially in synovial fluid, and plays a supporting and stabilizing role for synovial cells and collagen fiber scaffolds. Hyaluronic acid preparation is a biological macromolecular substance extracted and refined mainly from the corpus cavernosum and human umbilical cord, and it appears as sodium hyaluronate salt. The sodium hyaluronate solution is highly viscoelastic, and in the high shear state (fast motion), the synovial fluid mainly behaves as elastic, and the sodium hyaluronate molecular network stores the amount, which plays the purpose of shock absorption and joint vibration reduction; in the low shear state (slow motion), the synovial fluid mainly behaves as viscous, and the energy is dissipated through the sodium hyaluronate molecular network, thus playing the role of lubrication. By injecting sodium hyaluronate into the joint cavity, it can help restore the rheological properties of synovial fluid and joint tissue matrix – viscoelasticity, relieve synovial inflammation, reduce the exudation of pathological joint fluid and relieve joint pain, as well as improve the intra-articular environment, create conditions for the synthesis of its own polymeric glass acid molecules, reduce the destruction of cartilage and promote the repair of damaged cartilage, its role in OA Its role in the treatment of OA has been proven in both basic experiments and clinical practice.
Preoperative preparation
(1) Prepare 18-20 gauge puncture needle and syringe.
(2) After strict local sterilization, the operator holds the syringe in the right hand and fixes the puncture site with the left hand. When the needle enters the joint cavity, the right hand does not move, fixing the needle and syringe, and the left hand draws the syringe barrel spigot to perform operations such as fluid extraction or drug injection.
Puncture method
The patient is seated with the knee flexed and the lower leg naturally lowered, so that the knee joint is relaxed. Disinfect with 2.5% iodine, deiodize with 75% ethanol, lay a sterile towel, and take the medial or lateral side of the patella as the puncture point. A 5ml syringe was used to puncture the joint cavity, and there was a breakthrough sensation when puncturing the joint cavity, and there was no resistance to drug injection. If there is joint effusion, withdraw the effusion and slowly inject 10ml of 0.25% lidocaine (containing 5mg of trimethoprim, 0.5mg of trimethoprim in each ml). The treatment plan was adjusted from the third time onwards, as follows: 2.5ml of sodium vitrate injection was injected into the joint cavity, and the same treatment was given to the surrounding painful points.
After routine disinfection, the knee was bent at 90°, and the infrapatellar medial or lateral approach was made. A disposable syringe (5ml size) was used to puncture into the joint cavity, and the joint fluid was pumped out as much as possible without returning blood. After injection, cover the injection eye with sterile dressing and move the joint passively so that the drug can be evenly distributed in the joint cavity. 1 time/week, alternately from the inner and outer side, 5 weeks as a course of treatment.
Shoulder arthrocentesis
The affected limb is mildly abducted and externally rotated, and the elbow joint is flexed. The joint cavity is punctured vertically between the humeral tuberosity and the rostral process. It can also be performed from the anterior border of the deltoid muscle below the tip of the rostral process, in a posterior and lateral direction.
The shoulder joint puncture route can be anterior or lateral to the shoulder joint, often at the anterior border of the deltoid muscle. Shoulder joint puncture and injection method: Sitting or supine position, the affected shoulder joint is exposed, 1.5~2 cm outside the rostral process and then 1.5~2 cm downward as the puncture point, strict puncture sterilization and towel laying procedures, wearing sterile gloves, paying attention to the strict standardized aseptic operation technique, applying a common No. 7 injection needle to puncture the skin vertically, with a sense of falling into the joint cavity, and applying sterile dressing for 24 h after injection.
Elbow joint
The puncture point of the elbow joint is usually between the posterior hawk’s-jaw and the humeral epicondyle. In view of the above-mentioned route of the important vascular nerves in the elbow, the puncture and surgical access to the elbow joint are mostly performed on the dorsal and dorsolateral sides of the joint.
The elbow joint is flexed at 90o, immediately proximal to the radial tuberosity, and the needle is inserted anteriorly and inferiorly behind it, where the joint capsule is most superficial and the radial head is palpable. It can also be inserted medially and anteriorly between the tip of the ulnar hawk’s beak and the lateral epicondyle of the humerus. It can also be inserted anteriorly and inferiorly through the triceps tendon above the ulnar eminence and into the joint cavity.
Wrist joint
The puncture point of the carpal joint can be on the radial side of the ulnar styloid process or between the thumb extensor tendon and the intrinsic extensor tendon of the index finger, either through the ulnar styloid process or below the lateral aspect of the radial styloid process and vertically downward.
Hip joint
The puncture point of the hip joint is at the midpoint of the line between the anterior superior iliac spine and the pubic crest, 1 cm lateral to the femoral artery, and the needle is inserted vertically.
At the midpoint of the line connecting the anterior superior iliac spine and pubic symphysis, 2 cm below the inguinal ligament, the lateral aspect of the femoral artery is punctured vertically; it is also advisable to puncture from the superior border of the greater trochanter parallel to the lower extremity and inward and upward through the femoral neck (Figure 9-33).
Knee joint
The puncture point of the knee can be approximately 1 cm below, below, above, or above the patella medially.
The intersection of the horizontal line of the superior patellar border and the vertical of the external patellar border is used as the puncture point, through which the joint cavity is punctured inwardly and inferiorly; the needle can also be inserted posteriorly through either side of the patellar ligament immediately inferior to the patella.
Ankle joint
The puncture point of the ankle joint can be between the anterior tibial tendon and the medial ankle or between the long toe extensor tendon and the lateral ankle. The needle is inserted immediately above the tip of the outer or inner ankle, inward and upward, and into the joint capsule via the ankle between the ankle and the adjacent talus.
Precautions
(1) All instruments, drugs and operations should be strictly aseptic, otherwise infection of the joint cavity may result.
(2) The needle should be inserted while suctioning and drawing. Pay attention to whether there is fresh blood flow, if there is, it indicates that the puncture has entered the blood vessel and the puncture needle should be withdrawn a little and the direction should be changed before continuing to insert the needle. In addition, when the fluid is pumped, the puncture needle is then slightly pierced into a small amount, and the fluid in the joint cavity is pumped out as much as possible. Do not penetrate too deeply to avoid damaging the articular cartilage.
(3) Repeatedly injecting steroids in the joint can cause joint damage, therefore, no more than 3 injections of steroids should be given in any joint.
(4) In addition to microscopic examination, bacterial culture and antibiotic sensitivity test, careful visual observation should be done on the extracted fluid to initially determine its properties and give timely treatment. For example, normal synovial fluid is straw-yellow, clear and transparent, if it is dark red stale blood, it is often traumatic, the drawn blood contains fat droplets, it may be intra-articular fracture, turbid fluid suggests an infection; if it is pus, the diagnosis of infection is determined no different.
(5) If there is significant fluid accumulation in the joint cavity, the puncture should be dressed with pressure and given appropriate fixation. The time of re-puncture should be determined according to the amount of fluid accumulation, and usually 2 punctures per week are sufficient.
Treatment effect
It should be clearly explained to the patient that it is a slow-acting drug and the effect is usually very obvious only after 2 injections. 5 injections is a course of treatment. The effect can last from 6 months to 18 months, or longer, depending on the severity of the disease and the patient’s care of the knee. The pain is significantly reduced or disappears the day after the injection, and function returns to normal or almost normal.
Side effects
Occasionally, there may be discomfort and swelling after injection, and some people may experience more pain and swelling the night after injection. It is not a pain reliever, so do not expect the pain to be relieved immediately after the injection. Itchy skin after injection will disappear on its own after 2 to 3 days without treatment.