Fractures of the femoral neck in children are clinically rare, with an incidence of only 0.3% to 3.6% compared to adults. However, if the fracture is not treated properly, the sequelae such as non-union, ischemic necrosis of the femoral head, y-inversion deformity, premature closure of the femoral epiphysis, etc. are likely to occur, so the treatment requires a more reasonable method of repositioning and fixation according to the characteristics of children.
From March 2004 to September 2006, 12 cases of femoral neck fractures in children were treated in our department, all of which were fixed with closed reduction and 4.5-mm diameter hollow compression screws. The clinical results are summarized as follows.
1. Clinical data
Among the 12 cases in this group, there were 9 males and 3 females, aged 6-12 years old, average 8 years old, 2 cases of car accident, 1 case of self-inflicted fall, 9 cases of fall injury, 5 cases of left side and 7 cases of right side, all were closed fractures, 11 cases with 2 hours to 7 days after the injury, and 1 case with 10 days. According to the classification of Colonna [1], there were 3 transcervical fractures and 9 basal fractures. There were 2 cases of ipsilateral femoral stem fracture, 1 case of contralateral femoral stem fracture, 3 cases of ulnar radius fracture, and 1 case of craniocerebral injury in combination.
2.Treatment method
The patients in this group were routinely performed supracondylar bone traction on the affected limb before surgery, which not only relieved the pain at the early stage of trauma, but also facilitated the reset of the fracture. At the same time, we actively improved the preoperative auxiliary examinations and treated the comorbidities in time. After the condition is stabilized, surgery should be chosen within 7 days, because children have strong repair ability, and if surgery is chosen too late, it will cause difficulties in the intraoperative fracture repositioning.
Two 1.0-cm-long incisions were made 2 cm below the greater trochanter of the femur, and two 1.5-mm-diameter kerf pins were drilled along the incisions toward the femoral head, with the head of the pins 0.3 to 0.5 mm below the epiphyseal plate of the femoral head. After measuring the length of the guide needle with a depth gauge, the appropriate hollow screw is selected and screwed along the guide needle with appropriate pressure, the guide needle is removed, and the incision is routinely sutured and dressed.
After surgery, the patient should be kept in supine position with the affected limb in abducted neutral position and wear anti-rotation shoes. After surgery, the patient was instructed to perform functional exercises of the quadriceps and ankle joints of the affected limb to prevent the occurrence of venous thrombosis in the lower limb, and was given oral Chinese medicine to clear heat and cool blood, activate blood circulation and remove blood stasis, and promote water retention and reduce swelling.
After 1 week, we started to practice the joint movement of the affected limb. According to the patient’s bone quality and the degree of intraoperative fixation, generally after 4 weeks, the patient could get out of bed to support the double crutches and move the affected limb without weight-bearing, not cross-legged, not lying on the side. 6 months after the fracture healing was confirmed by X-ray, the weight-bearing exercises of the affected limb were gradually carried out.
3. Treatment results
The postoperative radiographs of the 12 cases showed that the fracture was anatomically repositioned in 9 cases, nearly anatomically repositioned in 2 cases, and functionally repositioned in 1 case, and the hollow compression screw was firmly fixed. 12 cases had stage I healing of the surgical incision.
All 12 patients in this group were followed up for 6 months after surgery, with the shortest follow-up period being 4 months and the longest 12 months, with an average of 7 months, and the radiographs taken showed bony healing with an average healing time of 5 months (3 months to 6 months). No 1 case died. The hip function was evaluated according to the Harris scale [2] in 12 patients in this group after 6-month follow-up, with 8 cases of excellent, 3 cases of good, and 1 case of femoral head necrosis, with an excellent rate of 92%, and no sequelae such as hip inversion deformity, femoral head epiphyseal plate injury, premature epiphyseal closure, and shortening of the affected limb occurred.
4. Discussion
Because of the dense and tough bones in childhood, the violence that causes femoral neck fracture in children is often huge, mostly from falling injuries, car accidents, etc. Therefore, femoral neck fractures in children are often combined with abdominal organ injuries and other fractures, and the huge violence also causes serious displacement of the fracture and destruction of the surrounding blood vessels.
Therefore, the examination and treatment of children with femoral neck fractures should be done in a timely and comprehensive manner to prevent any missed diagnosis. The blood vessels supplying the femoral head in childhood are located within the joint capsule, with a segment located within the cartilage of the femoral head. The posterior epiphyseal cartilage above the femoral neck from the femoral head to the greater trochanter is very important for the normal lateral growth of the femoral neck. Injury not only affects the normal development of the femoral neck, but also damages the blood vessels within it, severely affecting the blood supply to the femoral head and resulting in ischemic necrosis.
Poor alignment and improper fixation of femoral neck fractures in children can cause non-union, femoral head necrosis, premature closure of the femoral head epiphysis or hip inversion, resulting in limb disability. If the tip of the pin passes through the epiphyseal plate and causes premature closure of the epiphysis and 15% shortening of the affected limb, good repositioning, strong internal fixation and early and correct functional exercise are very important.
In this group, we used 4.5mm diameter hollow compression screws to fix femoral neck fracture in children, which has the advantages of small trauma, easy operation and stable fixation, and the hollow nail’s own compression effect makes the fracture end close together, effectively preventing the occurrence of non-union and deformed fracture healing, using hollow compression screws to fix femoral neck fracture in children, abandoning the traditional method of multiple steel pins fixation on the femoral neck bone The risk of premature closure of the femoral epiphysis is greatly reduced by using hollow compression screw fixation.
At the same time, after hollow compression screw fixation of femoral neck fractures in children, no external fixation in plaster is required, and functional exercises of the limbs can be performed under guidance at an early stage, which prevents functional impairment of the limbs at a later stage and reduces the pain of the children.
However, hollow compression screws are not a panacea for the treatment of femoral neck fractures in children, and strict indications should be grasped for their clinical application. Through clinical treatment we have found that hollow compression screws are indicated for transcervical and basal type of femoral neck fractures in children according to Colonna’s classification. For the subhead type, the clinical use should be cautious because of the low proximal fixation range of the fracture and the poor fixation strength. For old childhood femoral neck fractures, internal fixation with bone grafting by incision and reduction hollow compression screws should be preferred.
The experience in surgery: ①The process of fracture repositioning should be as indirect as possible to preserve the blood supply at the fracture end, and if necessary, the needle can be percutaneously pierced on the anterior side of the hip joint, and the steel needle can be used to pry to achieve a more ideal fracture alignment and alignment.
The tip of the hollow nail should be 0.3-0.5 mm below the epiphyseal plate of the femoral head, too deep will injure the epiphyseal plate and too shallow will make it difficult to achieve firm fixation.
The distal hollow nail should be as close as possible to the femoral spine, because the femoral spine is the site of the greatest compressive stress during upright weight-bearing, and the hollow nail is fixed close to the femoral spine to enhance the fixation effect and reduce the occurrence of hip inversion later.