Most of the lateral condyle fractures of the humerus in children are caused by the straightening of the elbow joint, the abduction of the forearm, the dorsal extension of the wrist joint, and the prophecy of the wrist joint on the ground when the child falls, and the violent transmission through the radius to the radius cephalic impact on the lateral condyle, or the external violence impacts the olecranon beak of the ulna and then conducts it to the lateral condyle of the humerus, and at the same time, the extensor muscles of the forearm contract strongly to produce traction force and cause fracture and displacement. Most of the fracture fragments are composed of cartilage, including the radial part of the humeral trochlea, the distal radial epiphysis and the metaphysis of the humerus, and the fracture line generally reaches the radial part of the trochlear from the upper end of the lateral condyle of the humerus to the radial part of the trochlea, at an angle of 20° to the transverse section.
Anterior and lateral x-rays of the elbow joint can only show the center of ossification of the lateral condyle of the humerus and the metaphysis of the metaphysis, so it is easy to miss the diagnosis. The lateral condyle of the humerus is the attachment point of the extensor muscle group of the forearm, and after the fracture, the fracture fragment is displaced due to the traction of the radial collateral ligament and the extensor tendon, and because it is an intra-articular epiphyseal fracture, the broken end is soaked in synovial fluid, which inhibits the formation of fibrin and callus, and is prone to fracture non-union, resulting in complications such as elbow joint dysfunction and elbow valgus deformity.
Fracture classification
Milch Typing:
Classification according to the anatomical location and direction of the fracture line:
Type I: The fracture line enters the joint through the epiphysis of the humerus.
Type II: The fracture line enters the joint through the trochlear site of the humerus, which can cause instability of the humeral-ulnar joint.
Clinical classification:
Fractures are classified according to the degree of displacement (Fig. 1):
I. Degree in situ fracture with intact articular surface.
Second-degree fractures were displaced ≤ 2 mm without horizontal reversal.
Third-degree fracture displacement > 2 mm, combined with significant displacement and overturning.
Fig.1 Clinical classification of lateral condyle fractures of the humerus
Imaging diagnosis
It is of great significance to carry out effective evaluation of lateral condyle humerus fracture to guide clinical treatment, and X-ray examination is widely used in clinical practice because of its convenience, cheapness and high popularity, and fracture classification can be carried out clinically according to the results of X-ray examination. However, some children with fractures have been found to have a poor prognosis during treatment, among which the children diagnosed with no significant displacement on initial X-ray have secondary fracture displacement during conservative treatment, so the accuracy of X-ray evaluation of children's lateral condyle fracture has been controversial. MRI has a high resolution for soft tissues, especially for epiphyseal and articular cartilage injuries. MRI is different from X-ray imaging, MRI can adjust the angle of the tomographic section according to the measurement needs, clearly display the fracture line and can measure and determine the maximum level of fracture space displacement, while X-ray has overlapping image structures, which is not conducive to the observation of fracture space and is not convenient for accurately measuring the width of gap displacement.
MRI is of better significance than X-ray in the diagnosis of lateral condyle fracture of the humerus, and the coronal 3D-FSPGR/3D-FS-FSPGR SEQUENCE is the most important sequence for diagnosing the lateral condyle fracture of the humerus and judging the integrity of the cartilage of the trochlear joint.
treat
1. Small incision reduction K-wire internal fixation:
Intravenous inhalation combination anesthesia or brachial plexus block anesthesia. The child is supine with the affected limb on a side table. Take the anterolateral side of the triceps brachii and brachioradialis space and make an incision 2~3cm long. The fracture ends are exposed from the anterior and lateral sides, and the blood clots and embedded periosteum between the broken ends are cleaned up to avoid dissection of the lateral and posterior soft tissues. A ø15mm K-wire was drilled into the fracture fragment as a lever, the proximal end of the fracture was clamped with Kocher forceps, and the lever was used to reduce it under direct vision, and the reduction was satisfactory with a ø15~20mm K-wire for internal fixation. The first K-wire was fixed from the metaphyseal part of the lateral posterior side of the fracture fragment at a 30° angle to the humeral shaft through the fracture end through the contralateral bone cortex, the second needle was fixed at an 80° angle between the humeral calves and the humeral shaft at an angle of 80° on the anterior side of the fracture fragment, and finally 1 K-wires were fixed between the two K-wires and the three K-wires were distributed in a multi-plane and multi-angle fan-shaped distribution. The position of fracture reduction and internal fixation was satisfactory confirmed by C-arm machine fluoroscopy, and due to the small ossification center of the lateral condyle of the humerus, elbow arthrography can be performed to show the cartilage of the distal humerus, which is convenient for observing the flattening of the articular surface. Bend the K-wire needle and cut it short and leave it outside the skin. The elbow capsule was sutured with absorbable sutures, the incision was sutured layer by layer, the 75% ethanol gauze was wrapped around the tail of the needle, a sterile dressing was bandaged, and the elbow plaster was fixed in place (Fig. 2).
Fig.2 A 4-year-old and 3-month-old child, a 4-year-old and 3-month-old child, suffered from swelling and pain in his right elbow due to a fall, limited his movement for more than 6 hours, and fractured the lateral condyle of the right humerus. General appearance photos 6 months after surgery, the elbow joint was normal in appearance, the function was well recovered, and the scar hyperplasia after the incision healed
Notes:
(1) For children with a history of elbow trauma, if the external elbow is swollen and tender, it is necessary to be alert to the possibility of lateral condyle fracture of the humerus, and in addition to the anterior and lateral X-rays of the elbow joint, 20° oblique X-rays should also be taken to avoid missing the diagnosis.
(2) The blood vessels of the lateral condyle of the humerus enter the posterior side of the condyle and the articular cartilage near the beginning of the elbow muscles from the outer edge of the beginning of the joint capsule.
(3) The K-wire needle should be fixed accurately, so as to avoid multiple needle threading into a sieve sample, aggravating the injury, and even leading to the lack of K-wire holding force, loosening, needle withdrawal and other complications.
(4) The K-wire needle tail is left outside the skin, 75% ethanol yarn is wrapped around the needle tail, the gypsum support is fixed externally, and the cast-type gypsum is changed to immobilization after the swelling of the affected limb is reduced, and there is no need to change the dressing, which can not only reduce the difficulty of nursing, but also reduce the occurrence of needle irritation reaction.
(5) After X-ray examination 4~6 weeks after surgery shows that the fracture has healed, the castular cast can be removed, the K-wire can be removed, and the child should begin to perform autonomic function exercises of the affected limb, paying attention to avoiding strong passive pulling.
2. Arthroscopic reduction and percutaneous fixation:
The children were treated with general anesthesia + brachial plexus block anesthesia, supine position, abduction and blood expulsion of the affected limb, anterolateral and posterolateral sides of the fracture end were taken as double-channel skin incision points, and 4.0mm elbow arthroscopy and working channel were placed after progressive expansion. Drain the blood accumulation in the joint cavity, inject normal saline to obtain the microscopic operation space and observe the fracture fracture end, grasp and clean the fracture end and the blood crust in the joint cavity with a planing knife and basket forceps, supinate the forearm, flex the elbow, and push the top fracture fragment with percutaneous thumb or mosquito forceps under wrist extension to anatomically reduce the fracture articular surface, if it cannot be reduced under arthroscopy, the extended incision is open reduction. After the fracture was reduced, three 2.0mm K-wire C-shaped arm X-ray machines were taken and percutaneously placed for fan fixation, and the operation was completed after the fracture was stabilized, the normal saline in the elbow joint was squeezed and discharged, the K-wire was bent, the needle tail was left under the skin, the incision was sutured, the elbow was flexed at 90°, and the forearm was fixed in a neutral plaster cast (Fig. 3).
Fig.3 A 7-year-old male patient was admitted to the hospital with "swelling and pain caused by a fall injury to his left elbow with limited movement for 4 hours", and the lateral condyle fracture of the humerus was fixed by microscopic reduction. 1a: Jakob third-degree lateral condyle fracture confirmed by preoperative CT; 1b: X-ray re-examination 1 month after surgery showed that the fracture was healed; 1c, 1d: X-ray re-examination at the last follow-up showed that the alignment of the affected limb was acceptable
Arthroscopic reduction percutaneous internal fixation can clearly observe the articular surface under direct vision and magnification, and provide a more satisfactory reduction quality for Jakob II and III. lateral condyle fractures, the fixation principle is the same as that of open reduction, the incision is small and the clinical effect is certain, and there are no serious complications, which can become a minimally innovative choice for the treatment of children's lateral condyle humeral fractures, but the microscopic reduction technique needs to be learned for a long time to provide a more satisfactory reduction quality, and the long-term efficacy requires a larger sample size and longer-term follow-up, in order to be further promoted in the future.
3. Open reduction and internal fixation:
The anterolateral Kocher approach was taken to cut the skin, separated into the joint capsule along the brachioradialis and triceps space, exposed the fracture end, removed the blood crust and embedded soft tissue, and dissected and reduced the fracture articular surface. Three 2.0mm K-needles were inserted percutaneously into the fan fixation under the X-ray machine of the C-shaped arm X-ray machine, and the operation was completed after the fracture was stabilized, the K-wire needles were bent, the needle tail was left under the skin, the incision was sutured, the elbow was flexed at 90°, and the forearm was fixed in a neutral plaster.
4. Elbow arthrography closed reduction and percutaneous K-wire fixation:
Brachial plexus block is operated under anesthesia, and children under 6 years of age are assisted with basic anesthesia. The child is in a supine position, and the body is covered with a lead coat. Take the posterior needle insertion point of the elbow joint, inject 05~10ml of iohexol into the elbow joint cavity, and observe the degree of fracture displacement and the continuity of the articular surface according to the contrast agent shown by the contrast agent under C-arm machine fluoroscopy, if the fracture end is displaced < 2mm and the articular surface is continuous, percutaneously fix it from the lateral condyle of the humerus with 2~3 ø15mm K-wires, and the maximum angle between K-wires is as close as possible to or > 60°; If the fracture is displaced ≥ 2 mm and the articular surface is discontinuous, and the fracture fragment is not inverted, the upper limb on the affected side is pulled by two physicians in the elbow position, and the bone fragment is squeezed under mild varus stress in the pronation position for fracture closure reduction. If the fracture cannot be anatomically aligned or combined with the fracture fragment inversion, the surgeon will first use a ø15mm K-wire to pry the reduction to correct the reversal, and then reduce, evaluate, and fix. The end of the K-wire needle is bent and cut and left outside the skin, and the end of the needle is padded with sterile gauze. The patient was externally fixed with a plaster cast at 90° of elbow flexion, and the external fixation of the plaster cast was removed 4~6 weeks after surgery, and X-ray was re-examined 8~12 weeks after surgery, showing that the fracture line was blurred and there were signs of fracture healing, and the K-wire needle could be removed, and the elbow joint function exercise should be rechecked regularly (Fig. 4).
Fig.4 A 5-year-old male with a fracture of the left lateral condyle of the humerus, Jakob type III., underwent closed reduction of the elbow arthrography and then was treated with a picochet's needle A. Preoperative X-ray, showing the fracture of the left lateral humerus, B. Intraoperative C-arm machine image, showing continuous cartilage on the articular surface, good reduction of the fracture end and then cross-fixation with a pixel's needle;C. X-ray 10 weeks after surgery, showing that the fracture had healed and the internal fixation was in good position and no loosening;D. X-ray 18 months after surgery showed that the fracture was well healed and the joint structure was normal;E. Gross photographs at 18 months postoperatively showed good function of elbow extension, flexion, and internal and external rotation of the forearm
The use of elbow arthrography closed reduction and percutaneous K-k's needle fixation in the treatment of lateral humeral condyle fracture in children can clearly show the cartilage components of the distal humerus in children, which is helpful to judge the degree of displacement of the fracture and the quality of closed reduction, and avoid unnecessary open reduction and complications.
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