total shoulder arthroplasty

Total shoulder joint replacement is artificial humeral head replacement plus scapular surface replacement. The remission rate of shoulder joint pain can reach 80%-90%. The differences in shoulder joint activity and function recovery are different due to the difference of primary lesions of the shoulder joint, the technical level of the doctor and the enthusiasm of the patient for treatment. Large; total shoulder joint replacement has the same service life as other joint replacements, and even better than other joint replacements. The long-term follow-up results of revision rate are less than 10%, and the average rate of shoulder scapular prosthesis is only 4.3%. Postoperative recovery of shoulder function is closely related to the reconstruction and rehabilitation of rotator cuff and deltoid muscle, and the direction of prosthesis implantation. Therefore, total shoulder arthroplasty is a very difficult operation. Treatment of diseases: unstable shoulder joints, traumatic shoulder joint dislocation, shoulder joint tuberculosis Indication Artificial total shoulder arthroplasty is suitable for: The main indications are pain associated with lesions on both sides of the humeral head and joints, followed by functional and motor disorders. include: 1. Osteoarthritis includes both primary and secondary. Because 89% to 95% of patients have intact rotator cuffs, it is an ideal indication for artificial shoulder replacement. 2. Rheumatoid arthritis When the rotator cuff lesion develops irreversibly and is accompanied by bone defects, although artificial shoulder joint replacement can effectively relieve pain, functional recovery is often unsatisfactory, and patients should be encouraged to perform early surgery. 3. The advanced stage of traumatic arthritis has similar pathological changes as osteoarthritis, but it is often accompanied by muscle and joint capsule damage and scar, sometimes combined with blood vessels and nerve damage, and the patient's soft tissue structure conditions should be carefully evaluated. . 4. Cuff tear arthropathy This is one of the most difficult joint diseases. Manual total shoulder arthroplasty can relieve pain, but because extensive rotator cuff damage is difficult to repair, only limited rehabilitation goals can be performed to increase joint stability. 5. Artificial shoulder joint revision includes scapular prosthesis loosening, fracture, sinking and technical errors of artificial humeral head implantation. 6. Other osteonecrosis, tumor, shoulder joint dysplasia, old infections, etc. If the lesion is confined to the humeral head, or the scapular articular cartilage is only mildly softened, only artificial humeral head replacement may be performed. Contraindications 1. Recent or active infections Although some doctors have not used infection as a contraindication for artificial joint replacement today, they have the third and fourth generation antibiotics and antibiotic-containing bone cement. However, most doctors still regard it as a general condition. Taboo. 2. The deltoid and rotator cuff artificial shoulder joint maintains the space between the shoulder blade and the tibia. It has no function in itself. The lack of power of the artificial shoulder joint replacement is meaningless. This type of patient, if there is a pain in the shoulder joint, can choose shoulder fusion. If it is a single deltoid or rotator cuff, it is not a contraindication. 3. Neurogenic joint disease, especially when the lesion is still mild and stable, the surgery will accelerate the progression of the disease. 4. Unrepairable rotator cuff tear is a relative contraindication to shoulder replacement. 5. Extreme instability of the shoulder joint is also a contraindication for shoulder joint replacement. 6. Pain symptoms and dysfunction are mild. Preoperative preparation 1. Understand the extent of the patient's shoulder pain to determine the surgical indication. Analyze and identify the nature of pain to rule out pain and dysfunction caused by neck disease. 2. Check the body should start from the neck to learn more about the degree of shoulder dysfunction. Check the composition of the rotator cuff, the muscle strength of the deltoid muscle, and identify it with an electromyogram if necessary. The acromioclavicular joint should also be carefully examined to determine whether or not a plastic surgery procedure is performed. 3. Preoperative standard lateral X-ray film. In the plane of the scapula, the posterior anterior X-ray of the internal rotation, external rotation and neutral position of the shoulder joint can better show the lesion of the humeral head. Lateral radiographs clearly show the ankle joint space and articular cartilage involvement. CT and MRI will provide more information for preoperative understanding of shoulder joint disease. 4. Apply antibiotics intravenously 1 day before surgery to prepare the skin. Surgical procedure 1. Incision: From the front of the clavicle, through the condyle, along the anterior edge of the deltoid muscle, stop at the tibia of the deltoid muscle, about 10cm long. 2. Use the cephalic vein to confirm the pectoralis major and deltoid space. The deltoid muscle is separated under direct vision, and the anterior portion of the humeral shaft is cut to prevent damage to the branch of the sacral nerve. The cephalic vein and the deltoid muscle are pulled to the outside, and the upper third of the pectoralis major muscle is cut. If the pectoralis major muscle contracture, the stop point can be completely cut off, but care should be taken not to injure the biceps brachial sac. Parallel to the deltoid muscle deltoid space, cut the thoracic fascia, up to the sacral ligament. The acromion of the aortic shoulder artery located at the leading edge of the sacral ligament of the ankle was ligated. The biceps short head and the diaphragm are pulled inward. 3. Cut the shoulder ligament and check the acromioclavicular joint. According to clinical symptoms and signs, bone resection or Mumford clavicle resection can be used. Once the lateral clavicle resection is performed, the stop points of the trapezius and deltoid muscles need to be reconstructed. The upper arm is abducted by 25°, and the deltoid muscle is protected by a gauze pad and further pulled outward. Remove some of the shoulders and slide the wall to clear the gap under the shoulder. 4. The shoulder joint is flexed, externally rotated, and ligated to the anterior circumflex vessel located at the lower edge of the subscapularis muscle. Before cutting the rotator cuff, bend the elbow 90° and try to rotate the shoulder joint. If there is no restriction on external rotation, the subscapularis tendon and joint capsule are cut 1cm inside the small nodule. Due to long-term fixation and lesions, most patients have limited external rotation. If the passive external rotation <30°, the scapularis tendon should be extended. After cutting off the first half of the subscapularis tendon, turn to the medial plane and cut inward to the iliac-muscle junction. The subscapularis muscle is pulled to the medial side, and the switch capsule is cut along the inner side of the joint, up to the upper boundary of the rotator cuff, and if necessary, extended to the base of the condyle. Keep the joint capsule attached to the tibia and prepare for extension of the subscapularis muscle. This extends the subscapularis muscle 2.0 cm without affecting the stability of the shoulder joint. 5. External rotation, extension, and abduction, so that the humeral head is prolapsed. The synovial membrane, the bursa and the free body are cleaned, and the bony prominence at the edge of the humeral head is trimmed to determine the edge of the joint surface. When removing the bony prominence below the humeral head, take care to avoid damage to the phrenic nerve. Refer to the position of the humeral head prosthesis to determine the height and angle of the humeral head osteotomy, generally 50° with the longitudinal axis of the humerus. Excessive removal of the humeral head will affect the tension of the rotator cuff and may cause a large nodule impact. . The artificial humeral head should be higher than the large nodule and tilted back 30°~40° (only when the old shoulder joint is dislocated, the posterior tilt angle of the humeral head can be reduced to the neutral position) to increase joint stability. The osteotomy direction was 35° external rotation of the humerus, perpendicular to the horizontal plane, and the humeral head was cut from the front to the back with a wide bone knife or a chainsaw. Do not remove too much bone, and only remove the articular surface of the humeral head. In this process, it is necessary to avoid damage to the large nodules and the anterior superior tendon and biceps longissimus. Further remove the bones under the head and back of the humerus. The bony prominence and granulation tissue of the biceps interdivision should also be cleaned up. According to the prosthesis used, the reaming and medullary pulp should be performed. The reaming needle should be placed on the lateral side of the humeral head section, 1 cm behind the biceps groove. Most patients have loose tibia and need to prevent fractures. Insert the trial mold, check the height of the prosthesis, the backward tilt and the thickness of the head, and select the type of the humeral head prosthesis that matches the height of the cut humeral head. Remove the test piece. 6. The upper arm is abducted and the deltoid muscle is relaxed. Place a hook on the back of the shoulder blade, pull the proximal end of the humerus to the back, and remove the joint lip, but keep the long head of the biceps. A Darrach hook is placed in front of and below the glenoid to protect the phrenic nerve and further reveal the glenoid. The articular cartilage was removed with a Cobb stripper. Check the shoulder for wear and bone defects and remove residual scapular cartilage. Usually the back of the shoulder is broken, the front edge of the shoulder blade needs to be deepened to rebuild the correct inclination. Most of the company's tools have joint honing, but for the tight joints, the high-speed grinding can better grind the joint. Picture. Care should be taken to remove cartilage without exceeding the subchondral bone because the glenoid prosthesis requires complete subchondral bone support. Regardless of whether the shoulder prosthesis is fixed to the joint dome by keel or bolt, the prosthesis should be placed in the center of the base of the condyle to reduce the risk of perforation of the scapular neck. For example, if the trailing edge wear is obvious, if the leading edge is not lowered, the prosthesis will be excessively backward, and the anterior edge of the scapular neck will be perforated. If the scapular neck is perforated, the cancellous bone is taken from the resected humeral head before filling the bone cement. Fill in the bone defect to prevent bone cement from seeping and avoid thermal damage to the subscapular nerve. In order to firmly fix and reduce the risk of loosening, the shoulder prosthesis must be firmly placed on the subchondral bone of the shoulder blade. There should be no swing. When the joint prosthesis is placed in a poor position, it cannot be adjusted with bone cement. Before using bone cement, use a pulse flush to clean the joint to remove bone debris and blood. The gauze soaked with epinephrine or thrombin is filled into the bone groove or nail hole to stop bleeding. Fill the bone cement in the early stage of cement solidification, then insert the gauze into the bone groove or nail hole with the vascular clamp, pressurize the bone cement, repeat the process 3 to 4 times, and place the bone cement only in the bone groove or the nail hole. There is no bone cement on the subchondral bone. Insert the joint prosthesis and continue to pressurize with the thumb until the cement is hardened. You can also use the company's pressurized instruments to hold the glenoid prosthesis. If the shoulder has a bone defect, bone grafting is required. Defects are classified into light, central (larger cavity defects), marginal or segmental. The central bone defect is most common in rheumatoid arthritis. A bone hole can be drilled in the center of the shoulder blade to determine the depth of the scapular neck. Those with a depth of <1 cm must be bone grafted. The bone is usually bone grafted from the humeral head. The posterior marginal defect may not be implanted, and the posterior tilting of the scapula may be offset by the anterior tilting humeral prosthesis, so that the sum of the two is 30° to 40°, and the higher edge can be used to match the lower edge. Low edge, when the defect is large, bone graft or large prosthesis can be used. According to the degree of joint wear, Dutta et al. proposed a corresponding treatment method: 1~2mm light wear, lowering the higher edge to match the lower edge; 3~5mm wear, grinding the lower edge, but then Slightly larger, adjusted by anterior tilting of the femoral prosthesis; >5 mm of wear, bone grafting and screwing or large prosthesis. If cemented with bone cement, prepare the medullary cavity in a standard manner, rinse and dry the medullary cavity with a pulse, and pressurize the bone cement with a cement gun and cement plug. In order to reconstruct the tension of the deltoid muscle and avoid shoulder instability and weak muscle strength, it is necessary to choose a highly suitable humeral head. After the reduction of the humeral head, the humeral head should be able to move back and forth about 50% of the diameter of the humeral head on the edge of the glenoid. The subscapularis muscle must be long enough to be reattached to the humerus. The type of humeral head should be chosen to achieve a satisfactory degree of external rotation. 7. Check for rotator cuff injuries. Small rotator cuff tears can be repaired with edge-to-edge or end-to-end sutures. Most rotator cuff tears can be re-constructed after the tendon is released. If the tendon is not sufficiently free, the upper part of the subscapularis muscle and the small round tendon can be transferred upward to close the defect. 8. Drill holes in the tibia and pre-set the rotator cuff suture. The elderly routinely use bone cement to fix the artificial humeral head. The bones of the proximal humerus of the young and middle-aged tibia can be fixed by press-fit, and the elbow is flexed. The internal and external iliac planes are used as reference for the humeral head. The body is tilted backward by 30° to 40°, or the fixed wing on the shank of the artificial humerus is located just behind the biceps intercondylar groove to ensure that the artificial humeral head is tilted backward. In the neutral position, the humeral head should point to the shoulder joint and slightly higher than the large nodule. 9. Shoulder joint reduction. Check the mobility and stability of the shoulder joint, the upper arm is placed in the neutral position, and the artificial humeral head should point to the center of the shoulder. If the angle of inclination is appropriate, the upper arm should be able to rotate 90° outward without dislocation or subluxation. Pull the upper arm to check the deltoid muscle tension. Rinse the joint cavity thoroughly. 10. Before suturing the rotator cuff, check the slip of the subscapularis muscle. Due to the influence of the lesion, the subscapularis muscle often adheres to the base of the condyle and the neck. Adhesion should be loosened before repair. Generally only the subscapularis muscle is repaired and the joint capsule is not sutured. Such as the subscapular muscle contracture can be Z-shaped extension. When suturing the rotator cuff, the upper arm should be externally rotated by 40°, and the rotator cuff should be closed with the non-absorbent suture, and the sulcus can be sutured to make the lower shoulder gap wirelessly. Place a negative pressure drainage tube and suture the deltoid muscle of the pectoralis major muscle. Close the incision. complication The main concurrency certificates for total shoulder arthroplasty are: 1. Artificial shoulder scapular loosening Most patients with artificial shoulder joint replacement can see visible light around the artificial scapula on the X-ray film, but most of them are asymptomatic or not aggravated, no need for surgical revision. There is still a different understanding of this phenomenon. Because most patients have this light-transmissive tape on the X-ray film immediately after surgery, it is emphasized that the bone in the scapular bone marrow cavity should be removed and the bone marrow cavity should be dried before the shoulder scapular prosthesis is fixed with cement. This is not easy to achieve during surgery. A piece of bone cement can be filled into the bone marrow cavity first, and taken out before it hardens, so as to remove the bone chips and then quickly fill the bone cement. 2. Tibial fractures Due to the fixation of the lesions, the humerus often has osteoporosis, and the expansion of the medullary cavity or the insertion of the prosthesis may cause it to break. Once fractured, the long shank artificial humeral head can be replaced to fix the fracture. 3. Dislocation after dislocation can be closed under general anesthesia. 4. The ankle joint is unstable. 5. Treatment of failure of total shoulder arthroplasty (1) Artificial humeral head replacement. (2) shoulder joint revision surgery: the literature reported that the revision rate of the initial shoulder joint replacement was 5% to 10%. The main indication is to relieve the pain. Restoring the movement, muscle strength, function and stability of the shoulder joint is a secondary purpose. The most common cause of revision surgery is the looseness of the glenoid prosthesis, which usually requires removal of the prosthesis. Because of the few reports in the literature, the effect of shoulder revision surgery is still difficult to determine. It is generally considered that the revision of non-restrictive shoulder arthroplasty is not as good as the initial joint replacement. Conner et al reported 50 cases of shoulder revision surgery, excellent in 10 cases (20%), satisfactory in 21 cases (42%), and unsatisfactory in 19 cases (38%). The worst effect was a joint replacement patient with a proximal humerus fracture, and only 33% of patients were satisfied. Arroyo et al. repaired 17 cases with a matched prosthesis, 2 cases were excellent, 7 cases were satisfactory, and 8 cases were not satisfied. (3) Arthroplasty: For patients with drug-resistant infection, intractable pain, extensive bone loss, or soft tissue that is not allowed to re-implant the prosthesis, arthroplasty may be considered. Arthroplasty can effectively relieve pain, but the recovery of mobility and function is generally poor due to the loss of the shoulder axis. (4) Ankle arthrodesis: ankle arthrodesis for shoulder joint replacement failure with severe bone loss, chronic low-grade infection, multiple joint revision surgery failure, intractable instability, or rotator cuff, deltoid or tendon The shoulder arch is widely missing.

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