Ulna shaft fracture

　　(One) Double fracture of the ulna and radius

　　1. Direct violence: Commonly seen in blows or machinery injuries. The fracture is transverse or comminuted, and the fracture line is on the same plane.

　　2. Indirect violence: When falling, the palm touches the ground, the force is transmitted upwards to the middle or upper 1/3 of the radius, and the remaining force is transferred to the ulna through the interosseous membrane, causing a fracture of the ulna. Therefore, the fracture line is low. The radius is transverse or serrated, and the ulna is short oblique, with fracture displacement.

　　2. Twisting violence: While subjected to external force, the forearm is also subjected to a twisting external force, causing a fracture. When falling, the body tilts to the same side, the forearm excessively pronates or supinates, and spiral fractures occur in both bones. Most are caused by the ulna斜向桡骨外下，fracture lines are consistent, the fracture line of the ulna shaft is above, and the fracture line of the radius is below.

　　The common complications and possible causes of ulna shaft fractures are as follows:

　　(1) Fracture nonunion: The anatomical relationship between the ulna and radius is complex. The lower 1/3 segment of the ulna and radius is mainly surrounded by tendons, with poor blood supply to the surrounding soft tissues. Both ends of the ulna and radius form joints, and during pronation and supination, the two ends of the bone move in unison around the ulna as the axis, not bearing rotational force. However, the ends of the ulna can twist relative to each other, affecting the healing of the fracture.粉碎性骨折 bone defect, severe surrounding soft tissue injury; microvascular embolism of the periosteum, leading to periosteal necrosis, affecting ossification; unsuitable methods and materials for internal fixation.

　　(2) Infection: Mainly related to prolonged exposure of the wound after injury, incomplete debridement, and severe soft tissue injury.

　　(3) Forearm intermuscular interval syndrome: Often due to severe soft tissue injury, improper manipulation during reduction,粗暴 surgery during open reduction, and failure to promptly and actively implement various measures for edema reduction and hemostasis, causing continuous increase in intramuscular interval pressure, as well as excessive tightness of splints or plaster during external fixation.

　　(4) Limited rotation function of the forearm: Commonly occurs in patients with closed reduction, where the fracture ends have not reached anatomical reduction, crossed healing, or bridging between two bones. Contracture of the interosseous membrane, adhesion of soft tissue scars, and constriction of the superior and inferior joint capsules are also important causes.

　　(5) Pressure sores: Often occur after closed reduction and fixation of fractures due to plaster shaping or bone splitting pad squeezing. Local edema and poor blood supply of the skin are also important reasons.

　　After injury, subcutaneous hematoma at the fracture site is easy to be found, which has obvious tenderness and can touch the bone friction sound between the fracture ends. During clinical examination, attention should be paid to the position of the radius head and the swelling and tenderness of the elbow to avoid missing the dislocation of the radius head. Dislocation fractures often occur, so for this type of fracture, there is no deformity, no bone friction sound, only local swelling and tenderness.

　　Radius shaft fractures are mostly caused by direct violence. They are more common in sudden attacks by external forces, such as when patients raise their hands to block their head and face and are struck directly by a stick. Prevention should avoid the forearm being injured by external forces.

　　When diagnosing radius shaft fracture, in addition to relying on its clinical manifestations, it is also necessary to use auxiliary examinations. X-ray radiography is the main examination item for radius shaft fracture, including the anteroposterior and lateral X-rays of the forearm of the elbow and wrist. In addition to these, there are currently no related laboratory tests.

　　(1) Avoid blind supplementation of calcium Calcium is an important raw material for bone formation. Some people think that supplementing more calcium after a fracture can accelerate the healing of broken bones. However, scientific research has found that increasing the intake of calcium does not accelerate the healing of broken bones, and for fracture patients who have been lying in bed for a long time, there is a potential risk of increased blood calcium and decreased blood phosphorus. This is due to the fact that lying in bed for a long time, on the one hand, inhibits the absorption and utilization of calcium, and on the other hand, the reabsorption of calcium by the renal tubules increases. Therefore, for fracture patients, there is no lack of calcium in the body. As long as the physical condition is strengthened and the exercise is carried out as soon as possible according to the doctor's instructions, it can promote the absorption and utilization of calcium by the bones, accelerate the healing of broken bones. Especially for patients who lie in bed after a fracture, blind supplementation of calcium is of no benefit and may even be harmful.

　　(2) Avoid eating too much pork bone Some people think that eating more pork bones after a fracture can promote early healing of the fracture. In fact, this is not the case. Modern medicine has proven through multiple practices that eating more pork bones by fracture patients not only cannot promote early healing but may also delay the healing time of the fracture. The reason for this is that the regeneration of bone after injury mainly relies on the function of the periosteum and bone marrow, and the periosteum and bone marrow can only better play their role under the condition of increasing bone collagen. The main components of pork bones are phosphorus and calcium. If a large amount of them is consumed after the fracture, it will promote the increase of inorganic components in the bone, resulting in a disorder of the proportion of organic matter in the bone. Therefore, it will have a hindering effect on the early healing of the fracture. However, the fresh pork bone soup tastes delicious and has a stimulating effect on appetite, so eating a little is not harmful.

　　(3) Avoid partial dieting Fracture patients often have local edema, congestion, hemorrhage, and muscle tissue damage, etc. The body itself has resistance and repair ability to these conditions. The raw materials for the repair of tissues, the growth of muscle, the formation of callus, and the elimination of blood stasis and swelling depend on various nutrients. Therefore, it can be known that the key to ensuring the smooth healing of fractures is nutrition.

　　(4) Avoid indigestible foods: Fracture patients often have a poor appetite due to the restriction of movement by casting or splints, along with swelling, pain, and mental distress. Therefore, they often have constipation. Therefore, food should be rich in nutrition, easy to digest, and defecate. Foods that are difficult to digest or cause bloating, such as taro, lotus root, glutinous rice, etc., should be avoided, and more fruits and vegetables should be eaten.

　　(5) Avoid insufficient water intake: Bedridden fracture patients, especially those with spinal, pelvic, and lower limb fractures, are very inconvenient to move. Therefore, they should drink less water to reduce the frequency of urination. Although the frequency of urination is reduced, even greater troubles are caused. If the bedridden patient has less activity, weakened intestinal peristalsis, and reduced water intake, it is easy to cause constipation. Long-term bed rest, urinary retention, can also easily induce urinary tract stones and urinary tract infections. Therefore, bedridden fracture patients should drink water as needed without any concerns.

　　(6) Avoid excessive sugar consumption: After consuming a large amount of sugar, glucose metabolism will be rapid, resulting in intermediate metabolic substances such as pyruvate and lactic acid.

　　For transverse, short oblique, and some butterfly fractures of the ulna, the fractures have certain stability and can be reduced and fixed with small splints or casts (in neutral position) regularly to check the position of the fracture. The fixation needs to be corrected in time, and it usually takes about 8 weeks. After X-ray confirmation of healing, the external fixation device can be removed for functional rehabilitation.

　　Fractures of the lower 1/4 of the ulna can cause rotational deformities of the distal fracture segment due to the traction of the pronator quadratus muscle. During reduction, placing the forearm in a pronated position can relax the pronator quadratus muscle and correct the rotational deformity of the distal fracture segment to facilitate reduction.

　　Displaced unstable butterfly fractures can be treated by open reduction and internal fixation first, fixing the butterfly fragment with screws to form an integrated whole with the proximal and distal segments of the ulna, and then fixing with a plate. When performing open reduction for comminuted fractures, try to preserve the continuity of the fracture fragments and periosteum, fix the proximal and distal segments with a longer plate (at least two screws per end), and do not need to insert screws into the comminuted bone fragments. After the operation, the cast should be immobilized for 4 weeks.

　　Multiple segmental fractures of the ulna are suitable for intramedullary fixation techniques (熟练者可在透视下经皮操作粗克氏针三棱针加压髓内钉)。