Internal fixation treatment of scaphoid fracture 1.Scaphoid is an irregular flat bone, located on both sides of the posterior and superior thorax, surrounded by muscles before and after. With the development of economy and transportation, it is becoming more and more common. As a result, scapular fractures are more often seen in high-energy injuries, mostly in the body and neck of the scapula. Because it is a part of multiple injuries and fractures, the diagnosis and treatment of scaphoid fractures often do not attract enough attention, and it is not uncommon for improper initial treatment or delayed treatment to cause shoulder joint and upper limb dysfunction. From August 2002 to April 2005, 18 cases of scaphoid fracture were treated surgically with good results, which are reported below. Clinical data and methods: 1. 1 General data: In this group, there were 18 cases, 12 males and 6 females, the youngest was 23 years old, the oldest was 62 years old, and the average was 42 years old. There were 10 cases of traffic accident injury, 4 cases of fall injury, 4 cases of heavy object crush injury, 7 cases of left symphysis and 11 cases of right symphysis; fracture sites of scapula: 6 cases of body fracture, 9 cases of neck fracture, 4 of them combined with scapular gland fracture and other parts of combined injury; 2 cases combined with clavicle fracture, 3 cases combined with more than 2 ribs fracture, 3 cases combined with hemopneumothorax, 13 cases were repositioned by incision, 1 – 2 reconstructed plates All 13 cases underwent incision and internal fixation with 1 or 2 reconstructive plates. 1.2 Surgical approach: under high epidural anesthesia or general anesthesia, in the healthy-side position, with the upper limb raised, along the lateral border of the scapula in the posterior approach, with an additional oblique incision along the scapular gland for combined scapular fractures. The skin incision is made all the way from the inferior border of the deltoid muscle, along the lateral border of the scapula, and obliquely to the inferior angle of the scapula. The posterior inferior border of the deltoid muscle is exposed, the infraspinatus and the lesser and greater circular muscles are exposed, the gap between the infraspinatus and the greater and lesser circular muscles is separated to reveal the axillary border of the scapular body and the lateral aspect of the neck, the periosteum is incised along the axillary border of the scapular body, and the posterior wall of the joint capsule is revealed by blunt separation under the deltoid muscle. The suprascapular nerve, which innervates the infraspinatus and infraspinatus muscles, should be protected by extending backward from the suprascapular incision, so that the scapular neck, scapular gland and scapular body can be clearly revealed. When dissecting the outer edge of the scapular neck, care should be taken not to damage the axillary nerve and the posterior rotator humeral artery that travels within the foramen quadratus. If the body is to be exposed, the subscapularis muscle can be dissected from the outer edge of the scapula and the body. Unless the dissection is too rough, there is usually no accidental injury to the axillary and radial nerves because the long head of the triceps muscle is protected. In addition to avoiding injury to the suprascapular nerve and artery, care should be taken not to injure the dorsal scapular nerve and descending branch of the transverse cervical artery. Internal fixation method: The fracture is fixed by reconstructive plate and screws. 5-8 holes of reconstructive plate and screws can be used for internal fixation on the scapular gonad or neck of the scapula or on the outer edge of the body, the plate can be bent to fit the irregular bone crest, and after the plate is laid and cut, the screws are drilled. The scapular neck drilling should pay attention to the direction of the drill bit to prevent entering the humeral glenoid cavity. Single or multiple screws are not applied alone because the scaphoid fracture block is weak and internal fixation by screws alone is not strong enough, and the angle of the screws is not easy to grasp intraoperatively, and the kerf pins are not strong enough, so the plate is most suitable. The fracture involving the scapular gland is fixed with another reconstructed plate. In this way, the scapula is firmly fixed and no additional fixation of the medial edge is required. For floating shoulder injury, clavicle fracture, proximal humerus fracture or rupture of the rostral ligament should be properly treated. The fracture of the acromion can be fixed with plates and screws to maintain the stability of the glenohumeral joint and to prevent the fracture of the scapular neck from healing abnormally. Postoperative management: After 2-4 days of postoperative suspension with a sling or triangular scarf to protect the injured limb, start to do arm swinging exercises, and gradually increase the auxiliary exercises and start active exercises 1 week after surgery. Most of the patients basically recovered their functions to nearly normal level in about 3 weeks. The average healing time of the fracture was 6-8 weeks, and the efficacy was evaluated according to the shoulder joint scoring system of the American Academy of Shoulder and Elbow Surgeons. Compared with the healthy shoulder joint, the functional recovery of the affected shoulder was 96.7%, the muscle strength of the affected limb was normal, and the ability to live and work was 95.4%. 2. 3. 2, 3. Discussion 1 Diagnosis of scaphoid fracture The mechanism of scaphoid fracture injury has direct violence, indirect violence. Most of them are high-energy injuries, car accident injuries, and most of them are accompanied by other fractures, thoracic and abdominal organ injuries, craniocerebral injuries, etc. The condition is critical, and there is no comprehensive physical examination in order to save lives, which leads to missed diagnosis. According to the mechanism of injury, the point of force, and the superficial location of the scapula, when the scapula is swollen, the skin is bruised with subcutaneous bruising, the bone rubbing sensation is felt, and the movement of the shoulder joint is limited, then the scapula fracture should be considered. Imaging: anteroposterior and axillary films should be taken. When it is difficult to obtain axillary films, tilt angle or scapular cut films are also acceptable. It is best to take true anteroposterior, lateral and glenohumeral axial views, i.e., orthogonal views with the center of the X-ray projection 30 degrees outward from the sagittal plane, lateral views with the center of the X-ray projection 30 degrees backward, and axillary views, and CT and 3D reconstruction are often used to further determine the extent and type of fracture. 3.2 Classification of scapular fractures Scapular fractures are classified as fractures of the articular glenoid, acromion, rostral process and scapular body, and fractures of the articular glenoid can be further classified as fractures of the glenoid rim, glenoid neck and through the glenoid cavity. According to the fracture of different parts of the scapula combined with Ma Yuanzhang[5] classified scapular fractures into : (1) body fractures, glenoid margin fractures, glenoid fossa fractures, which are further divided into 6 types: I -6 , anatomic neck fractures, surgical neck fractures, acromion fractures, scapular gland fractures, (8) rostral prominence fractures. Based on the location of the fracture in relation to the shoulder pelvis and the overall stability of the shoulder joint, scaphoid fractures can be classified as stable extra-articular fractures, unstable extra-articular fractures, and intra-articular fractures. Stable extra-articular fractures include scapular body injuries and injuries to the scapular process. It can be a single fracture or a compound fracture. Scapular neck fractures, even with some displacement, are often quite stable and are classified as stable extra-articular fractures. Unstable extra-articular scapular neck fractures are often combined with rostral or acromion fractures. The most typical combination is a clavicle fracture. A scaphoid fracture combined with a clavicle fracture or a scaphoid fracture combined with a fracture of the proximal humerus forms a floating shoulder (floating shoulder), which can lead to severe instability of the middle glenohumeral joint and is difficult to treat, usually requiring open reduction and fixation of at least a portion of the fracture fragment. The presence of rib fractures has little effect on glenohumeral stability, but attention should be paid to the presence of intra-thoracic organ damage to determine the order of resuscitation and timing of surgery.3,3 Surgical indications: It is important to emphasize that the vast majority of patients with scaphoid fractures, approximately 90%, can be treated nonoperatively with symptomatic treatment including slings and wraps for patient comfort, and the prognosis is usually very good. Only severely displaced and unstable fractures of the scapular neck, acromion, or rostral process are indicated for surgery. An indication for an articular glenoid fracture is a fracture that causes persistent subluxation of the humeral head, i.e., a dislocation of more than 3 mm in the anterior 1/4 or posterior 1/3 of the articular glenoid labrum. Scapular neck fractures are indicated by more than 5 mm of separation displacement in the cross-sectional or coronal plane and/or angular displacement of more than 20°. In the case of fracture of the scapular body, if the fracture block enters the glenohumeral joint, it may affect the shoulder joint movement and requires surgery; in the case of fracture of the acromion, if there is a fracture of the inferior rostral process with separation of the acromioclavicular joint; in the case of fracture of the acromion with significant displacement, accompanied by retraction of the fracture block into the subacromial space; in the case of severe fracture and dislocation that may cause rotator cuff dysfunction, surgery should be performed. 3.4 Most of the bones of the scapula are weak, but the lateral edge of the scapula and the bones of the scapular gland are stronger and can be used for internal fixation of the fracture. For scapular neck fractures, the outer ridge of the scapula is extremely suitable for internal fixation and is easier to reveal surgically than the inner ridge. Although a variety of internal fixation options are available for cervical fractures. With the exception of small fractures at the glenoid fossa, internal fixation with a single screw is not effective because the width of the outer ridge of the scapula is less than 0.5 crn and is oblique, and the fracture is deep there, even though the fracture can be well repositioned. However, it is not easy to control the direction with pins or screws along the dense bone ridge, and the bone is weak there, so screws cannot effectively fix the fracture block. At the same time, most of the neck fractures are insertional and comminuted fractures, and the fracture fragments are removed and fixed with a single screw will inevitably cause the neck to become shorter and the fracture will be difficult to be well aligned. Therefore, the steel plate can play a role in pulling or supporting the fracture, because the scapula is surrounded by muscles in front and behind, there is no problem of front and back displacement after internal fixation of the fracture, so the porous steel plate can be used only to pull or support the fracture. The reconstructed plate can be bent in all directions to fit the uneven crest of the scapula, and the plate can be easily drilled and screwed vertically after fitting. For severe comminuted fractures, pre-bent double plates can be used for internal fixation.