Early complications of external bone fixation are problems that may arise because of the procedure during external bone fixation surgery up to 1 week postoperatively. For example, potential threats and clinical problems such as possible injuries and trauma during fracture repositioning, osteotomy, instrument placement and steel pin penetration and placement. Such as neurovascular injury, limb swelling, incomplete osteotomy, improper placement of instruments and steel pins, and occasionally reversible or irreversible complications due to surgery such as osteofascial compartment syndrome and fat embolism.
(I) Nerve injury
Nerve and vascular injuries are extremely rare in clinical practice. Nerve injury after surgery will have different degrees of nerve irritation symptoms such as, abnormal sensation, motor impairment, as well as muscle atrophy and foot drop. It is generally believed that when the steel needle is threaded directly against the nerve, the front end of the needle can push it to the side. In addition to full understanding of the local anatomy and strict needle penetration techniques, the following issues need to be noted in the surgical operation of needle penetration.
1, choose a safer needle penetration location needle penetration location should avoid the main nerve to the maximum extent possible, in the danger zone, such as the proximal tibia (common peroneal nerve), distal humerus (ulnar and radial nerve) penetration needle, as far as possible, choose the full needle and half needle combination application of steel needle layout, if necessary, use penetration needle locator penetration needle.
2, choose a safe way to enter the needle if the steel needle is put on in the danger zone, should be relatively safe side into the needle, such as the small head of the fibula side, the humeral condyle as the side into the needle, or the application of penetrating needle locator through the needle.
3, needle penetration should be slowly into the needle, while observing the nerve reaction symptoms, if found to have nerve irritation symptoms should be withdrawn from the steel needle, from a new adjustment into the needle point penetration needle.
4.Cultivate the habit of safe operation such as making skin incisions, the plane of the scalpel must be pierced parallel to the direction of nerve and blood vessel travel.
5, intraoperative, postoperative nerve injury found, should take appropriate remedial measures, such as immediate replacement of the needle position, the appropriate application of nerve application drugs to assist in rehabilitation.
(B) Vascular injury
Vascular injury is very rare in clinical practice. Vascular injury can cause intraoperative bleeding, local hematoma, swelling of the limb, or even evolve into osteofascial compartment syndrome. Vascular injury can be caused by needle penetration or osteotomy operations. Steel needles in close proximity to blood vessels may trigger the possibility of chronic erosion injury, which can cause acute bleeding or pseudoaneurysm in case of infection or prolonged irritation of the needle hole. Although clinically inappropriate is rare, there have been reports of needle penetration in certain risk areas, resulting in important vascular injury and even amputation. For example, Lin reported a case of anterior tibial artery injury caused by the application of unilateral external fixator for tibiofibular fracture; Jakin reported a case of late injury to femoral artery caused by the application of Ilizarov external fixator, forming a pseudoaneurysm; we also had a case of deep femoral vessel pseudoaneurysm rupture when applying unilateral external fixator for femoral lengthening, which was cured by repairing with artificial vessel.
The prevention and treatment methods of vascular injury are similar to the principles of nerve injury prevention and treatment. In addition to fully understanding the local anatomy and avoiding nerve and vascular needle penetration, the following issues should be noted.
1, choose the safest needle piercing position needle piercing position should avoid the main neurovascular to the maximum extent possible, in the danger zone when piercing needles, as far as possible using half needle. When the blood vessels are found to be injured, bleeding, should immediately withdraw the steel needle, compression to stop bleeding, choose another needle location.
2, strict needle penetration procedures such as adjacent vascular location of needle penetration, as far as possible, the application of cannula programmed operation; in the danger zone wear put the whole needle, should be relatively safe side into the needle, or first 250px long 7 injection needle test penetration without error, and then along the test direction of needle penetration or application of needle penetration locator penetration needle.
3, to avoid thermal damage to the needle and soft tissue entanglement in the whole needle operation process, thermal injury or steel needle entanglement, can also cause neurovascular injury. The operation should be finger pressure to penetrate the needle out of the soft tissue, as well as to avoid continuous high-speed rotation.
4, establish minimally invasive awareness of the application of bone knife, wire saw, electric saw osteotomy, to avoid excessive stripping or accidental injury well-known blood vessels. When applying drilling or minimally invasive continuous hole osteotomy, avoid accidental injury to the contralateral blood vessels or nerves by the drill.
5.If nerve and blood vessel damage is found during and after surgery, corresponding remedial measures should be taken and the location of the piercing needle should be changed.
Once clinical symptoms of neurovascular injury are found or suspected, priority should be given to removing the suspected needles without waiting for “confirmation”.
(C) Limb swelling
External bone fixation itself rarely causes swelling of the limb, although chronic swelling of the limb has been reported, but the cause is not very precise. The cause of displacement may be related to the use of a circular external fixator with excessive cross-threading of pins, which affects blood flow. More often, the cause is related to the original injury, excessive soft tissue stripping during osteotomy, injury to nearby well-known vessels, causing blood leakage and poor drainage. In addition, factors such as trauma reaction, compression of blood vessels by steel needles and body position may also trigger tissue edema and limb swelling.
1, trauma-induced limb swelling serious closed fractures are often accompanied by different degrees of limb swelling, the application of external bone fixation treatment should be strictly in accordance with the principles of trauma treatment to eliminate limb swelling, and if necessary, incision and reduction should be performed. While providing effective fixation for fractures, external bone fixators should also provide convenience for the treatment of trauma. The number of steel pins should be reduced as much as possible to reduce the influence of steel pins on blood supply, and the external fixator should be sufficient to maintain stability under non-weight-bearing conditions, wait for the swelling to subside, and add additional steel pins before leaving the bed for exercise to increase the stability of fixation.
2. The swelling of the limb caused by osteotomy is related to poor drainage. A drainage tube must be placed during the operation and the drainage must be kept unobstructed.
3.Avoid piercing the needle near the blood vessels and the abdominal position of the muscle, especially the full needle; avoid piercing excessive full needles in the middle part of the limb, the proximal femur and the proximal humerus.
4.Postoperative tissue dehydration drugs can be routinely applied Postoperative once abnormal limb swelling is detected, close observation should be made and non-operative methods should be actively used to make the limb swelling subside as soon as possible. If the effect of non-operative measures is not obvious and the swelling tends to increase, further treatment measures should be considered in accordance with the osteofascial compartment syndrome.
(iv) Fascial compartment syndrome
It may be caused by the transverse passage of the nail through the fascial compartment or by increased intraosseous pressure after cortical cutting. This phenomenon has been reported in the use of external bone fixation alone, but rarely occurs. We have not seen it happen in the application of bone external fixation alone, but only in the application of internal and external limb lengthening, which should be fully understood, early diagnosis, treatment, so as not to cause serious consequences.
(E) Other problems
1, skin compression necrosis skin compression necrosis, including from the tension between the steel needle and the skin, the external fixator rod or steel needle pressure on the skin, and the placement of the limb by its own gravity and external fixator pressure, resulting in skin compression necrosis. When wearing steel needles intraoperatively, the needling technique should be strict, as much as possible in the functional or natural position of the limb, with no tension in the soft tissue. If there is tension, it should be cut and reduced without palliation to ensure that there is no tension between the skin and the steel needle. Ensure the distance between the external fixator and the limb to avoid postural or gravitational compression, and if necessary, sliding traction or elevating the affected limb.
2. Improper location of steel pins such as steel pins penetrating into the fracture line or joint. Once found, the steel needle should be promptly returned to its normal position or withdrawn for re-piercing. In the adjacent joints, it is best to operate or confirm the needle penetration with the help of X-ray fluoroscopy during or after the operation.