Femoral neck fractures account for approximately 3.58% of all fractures and are common in the elderly. At the same time, the number of young adult patients is increasing year by year. As the diagnosis and treatment of femoral neck fractures and theoretical research continue to advance, it is increasingly recognized that aggressive surgical treatment can greatly improve the quality of life of patients and prolong their lives. Multiple hollow compression threaded nail fixation of femoral neck fractures is the main method advocated at present. How to use the C-arm intraoperatively to quickly and easily understand the direction and position of the guide pin dynamically and to understand the alignment of the femoral neck fracture is the key to the success of the operation.
1. Data and methods
1.1 General data
There were 31 patients with femoral neck fractures, 13 males and 18 females, aged 45-78 years, with an average age of 62.5 years. According to Garden’s typing: 7 cases of type II 15 cases of type III 6 cases of type IV; or 7 cases of displaced type without displacement 21 cases of displaced type.
1.2 Preoperative preparation and timing of surgery
After admission, the preoperative examination was improved, and the patients were treated with blood pressure and blood glucose control and other medical conditions. 28 cases were treated with internal fixation of fracture and 3 cases were treated with artificial joint replacement. The patients were a patient with femoral neck fracture combined with osteoarthritis of the hip joint; a patient aged 78 years with pulmonary heart disease and in poor general condition; and a patient with loss of internal fixation three weeks after internal fixation. All 31 patients underwent emergency or early surgical treatment. The time of surgery in this group was 2-118 hours from injury, with an average of 24.5 hours.
1.3 Surgical method
After successful anesthesia, the patient was placed supine on the operating table with the affected hip elevated. Firstly, the shortened external rotation deformity was corrected by abducting the affected limb in the straightened position and abducting the affected limb in internal rotation. Two or three guide pins are inserted along the femoral neck with the aid of parallel guides. The C-arm X-ray machine should be used to view the femoral neck in the orthogonal position, and then the affected limb should be flexed and abducted in the frog position to observe the position of the guide pins in the axial position of the femoral neck. After all are satisfied, the depth of the guide pin is measured and 2-3 hollow pressurized threaded nails can be screwed in. If the initial repositioning is poor several times, limited incisional repositioning may be considered while revealing the longitudinal bone below the greater trochanter and exposing the anterior fracture line. After the satisfactory reset and strong internal fixation, the bleeding and blood clot in the joint cavity will increase the pressure in the joint cavity, resulting in the so-called “temponade effect”, so intra-articular puncture should be performed to reduce the pressure in the joint cavity, which has a certain effect on reducing the incidence of femoral head necrosis.
1.4 Postoperative treatment
Postoperatively, wear “ding” shoes and brake the affected hip and knee in the external booth. In addition to the application of antibiotics, apply drugs to improve microcirculation. Other precautions were the same as the general postoperative treatment of fracture.
2. Results
The average follow-up period of 31 patients was 16.5 months (8-36 months). 28 patients with internal fixation surgery showed anatomical fracture repositioning on X-ray. 26 cases had bony healing and 1 case had non-healing fracture, and 1 case had ischemic necrosis of the femoral head.
3. Discussion
3.1 Whether to perform internal fracture fixation or artificial arthroplasty
For the majority of patients with femoral neck fractures, K.R. Dai [1] et al. believe that effective internal fixation should still be the treatment of choice for fresh femoral neck fractures. [Haidukewych GJ [5] et al. concluded that the surgical approach for intracapsular femoral neck fractures should be selected according to the patient’s condition (age is more important than the degree of fracture displacement), and that for patients under 70 years of age, cancellous bone screws should be used first for fixation, regardless of fracture displacement; for patients over 70 years of age with In patients over 70 years of age with displacement, arthroplasty should be considered first. Especially for patients with subtrochanteric fractures, anatomic reduction and strong internal fixation should be attempted for the following reasons: (1) Although artificial joint replacement can move the limb and partial weight bearing as soon as possible and reduce bed-rest complications. However, with the development of internal fixation materials and the continuous improvement of surgical techniques, contemporary internal fixation can fully meet the above requirements. The fracture healing rate is also greatly improved. Most current literature reports postoperative healing rates of 85%-95% for femoral neck fractures, 93% for Cassebaum [4] and 96% for Asnis [4]. The postoperative healing rate of our fracture was 92.8%, but due to the small number of cases, it needs to be further explored. (2) Although a high rate of ischemic necrosis of the femoral head occurs in high fractures, less than 50% of patients required further treatment due to symptoms [2]. (3) Although faced with non-healing fractures, in the case of intracapsular fractures, the fracture site has no significant effect on healing or rarely does [3]. And this group of patients includes patients with non-high-grade fractures. Also, the treatment received was not exclusively artificial joint replacement. (4) Artificial joint replacement is relatively more traumatic and blood loss, faces possible revision, and is not a one-off. Of course, if the patient cannot be satisfactorily repositioned and firmly fixed or if the patient is in poor general condition and is not expected to be able to tolerate another surgery, or if the patient is suffering from mental disorders and cannot cooperate, we choose artificial joint replacement. In addition, for patients over 65 years of age, individualized treatment plans can be made based on the above conditions. Specific relative and absolute indications can be found in Kay’s Surgery, 8th edition, and are recognized internationally.
3.2 Principles of internal fixation for resetting femoral neck fractures
The principle of internal fixation for resetting femoral neck fractures is early minimally invasive anatomic reduction with reasonable multiple nail fixation. Early or acute surgery is conducive to the recovery of post-fracture vascular distortion, compression or spasm as soon as possible; maximum anatomical repositioning can obtain the maximum contact area, which is conducive to the reconstruction of femoral head blood flow and is an important condition for successful internal fixation; solid internal fixation, especially the multiple hollow compression screw internal fixation that has been widely popular in recent years, achieves good surgical results. The use of multiple hollow compression screws in this group achieved good surgical results and confirmed this view.
3.3 Need for orthopedic traction bed
In our experience, the necessary preoperative traction and good intraoperative anesthesia are the prerequisites for obtaining anatomical repositioning, which is an important condition for successful internal fixation. For this reason, we abandoned the previous method of repositioning with the help of an orthopedic traction bed. This method is not conducive to flexible adjustment of the position of the affected limb, limited movement of the affected hip, inadequate choice of different repositioning methods, and inaccurate traction. While lying supine on the general operating table, it is possible to use the Whitman method to traction the affected limb, while adding counter-traction at the root of the thigh, and after the original length of the limb is restored, perform internal rotation and abduction reset. More importantly, if this method is not good, a modified Whitman method can be chosen, i.e., traction with the hip and knee flexed in 90 positions. Proper internal or external rotation of the affected limb to correct the posterior or anterior tilt, to obtain the maximum degree of satisfactory reset.
3.4 Advantages and disadvantages of frog fluoroscopy of the affected hip in surgery
Frog fluoroscopy of the affected hip adopts a projection position in which the hip and knee are flexed and the thigh is externally rotated to 30 degrees from the table. In addition, the superiority of fluoroscopy of the affected hip in frog position can also be reflected in the femoral head medullary core decompression guide pin positioning, DCS fixation guide pin positioning and other internal fixation device surgery for femoral neck fracture. The disadvantage is that the surgical patient and the medical staff receive more radiation from X-rays, and protection should be strengthened.
In conclusion, fluoroscopic assisted repositioning of the affected hip in frog position allows for maximum repositioning and simplifies intraoperative fluoroscopic operations; the preferred treatment for fresh femoral neck fractures is fracture repositioning hollow screw internal fixation.