What Is the Articular Capsule?

An articular capsule is a membrane capsule made of connective tissue that attaches to the periphery of a joint and seals the joint cavity.

An articular capsule is a membrane capsule made of connective tissue that attaches to the periphery of a joint and seals the joint cavity.

Chinese name

Joint capsule

Foreign name

Articular Capsule

Classification

Fibrous layer on the outside and synovial layer on the inside

Function

Fastness is a combination of joint head and joint socket

Brief introduction

The fibrous layer of the joint capsule is composed of dense connective tissue

Joint capsule anatomy and composition

The joint capsule wall has two layers: the outer layer is the fibrous layer; the inner layer is the synovial layer. The fibrous layer is actually the migration of one periosteum from one bone to another. The fibrous layer is thick and tough, consisting of dense connective tissue and rich in blood vessels and nerves. Its shallow fibers are mostly arranged in rows; deep fibers are mainly circular fibers. The thickness of the fiber layer is not the same for all joints. Even in the same joint, the parts are also inconsistent. Generally, the joints with a small range of motion or heavy loads are thick and nervous. On the contrary, the joints are flexible. It is thin and slack. Some articular capsules lack part of the fibrous capsule, only a layer of synovium; others are significantly thickened, forming ligaments. The synovial layer is thin and soft, and is composed of loose connective tissue. It is lined with the inner surface of the fibrous layer and the periphery is attached to the edge of the articular cartilage. It lights up towards the inner surface of the joint cavity, which is covered with a layer of endothelial cells. The synovium secretes synovial fluid into the joint cavity. Synovial fluid is a slightly viscous and transparent liquid, which can reduce the friction of the connected bones in the joint. It is a lubricant. Synovial surfaces can form villi or folds into the joint cavity. Sometimes the synovial layer can bulge outward through the fibrous layer to form a synovial sac, often located between the tendon and the bone surface. Sometimes the synovial layer is not prominent, and it is only a deep nest, which is called a cystic recess.

Joint capsule imaging

The three joints of the elbow are in a common joint capsule. The articular capsule is attached to the articular cartilage edge at the lower end of the humerus, the two upper palate bases, the upper edges of the olecranon socket, and the coronoid process fossa, and the articular cartilage edges attached to the olecranon, coronoid process, and radial small head attached to the upper ulna and the radius Annular ligament. The joint capsule is loose and weak back and forth, which is conducive to the flexion and extension of the elbow joint. The fibers on both sides of the joint capsule thicken, forming the radial and ulnar collateral ligaments. Because the two side walls of the elbow joint are thick and strong, and the front and back walls are weak, it is easy to cause elbow dislocation.

In the elbow joint capsule, except for the cartilage, the humeral head, the ulnar notch and the radial head covered with transparent cartilage, other parts of the joint cavity are covered with synovial membranes. There is a large skin bursa between the skin and the humeral process. If it is involved, it can increase the occurrence of bursitis. The synovium is refolded at the distal end of the humerus to form the anterior coronal crypt and posterior humeral crypt, allowing full flexion and extension of the elbow joint. The crypt has the outer layer (fibrous layer) and inner layer ( Synovial layer) between anterior (2) and posterior (1) fat pads. When the joint capsule effusions, changes in the displacement of the front and back fat pads can occur.

Joint capsule related diseases and treatment

1. The traditional treatment for joint cysts (including fossa cysts and wrist tendon sheath cysts) is cystectomy, but the recurrence rate is high.

2. There are many ways to treat joint cysts, but they are difficult to completely and may have recurrence. Conservative treatment includes hand pressure, fluid injection or acupuncture. The total effective rate of the latter is 94.74% and the recurrence rate is 17.64%. However, the more accurate method is cystectomy. The traditional surgical recurrence rate is still high. Joint cysts are connected to the joint cavity. The joint cysts are treated as "joint hernias", the cysts are removed, the neck of the cyst is sutured, and the fascia, muscles or tendons near the opening are used. Tissues were repaired with joint capsule to strengthen the capsule wall, and then a strong plaster cast was applied for 2 weeks. This can greatly reduce the recurrence rate of joint cysts. Patients with recurrence in the conventional surgery group were only treated with cyst removal without repair and reinforcement of the defect area. One case of recurrence in the repair group was caused by insufficient soft tissue around the capsule wall and insufficient repair of the capsule wall; The other case was caused by the plaster cast being removed automatically and walking down one week after the operation. This also shows that the external fixation and braking of the gypsum tray is sufficient to ensure the solid healing of the capsule wall. In order to reduce the postoperative recurrence rate of joint cysts, it can be regarded as "joint hernia, and treated according to the principles and methods of" hernia ", closing the opening, strengthening the capsule wall, and performing strong external fixation for 2 weeks. This operation is simple and easy OK, the effect is exact, it is worth popularizing and applying.

Joint capsule clinical related technology

Articular capsule formation: If there is a slack or fissure in the superior glenohumeral and middle ligament, it should be repaired on the opposite side. The subscapularis tendon is 0.5 cm near the nodule nodule, and the pituitary muscle is cut longitudinally. 1/2, and free it proximally until it crosses the neck of the scapula to form the superficial scapularis muscle flap. The deep scapularis with a thickness of 1/2 and the fiber and anterior wall of the joint capsule are anatomically attached to the humerus. The cutting of the anterior lower joint capsule, the lower and posterior joint capsule stops, can make the shoulder joint external rotation and flexion, easy to show and operate, should avoid damage to the axillary nerve below the joint capsule, in the middle of the anterior joint capsule wall, smooth The direction of the articular capsule fiber is cut diagonally from top to bottom to form two upper and lower joint capsule flaps. A shallow groove must be made before the anatomical neck of the humerus to pull the lower joint capsule forward and tighten, and the outer edge is sutured. It is fixed in the external humerus torticollis, and the upper joint capsule is tightened forward and downward. It is superimposed and sutured on the surface of the lower capsule to prevent the humeral head from dislocating backward or forward and downward. Superficial muscle flap weight Sutured to the proximal small nodules. The acromion sac is closed and the incision is closed.