1.1 Patients
196 elderly patients (≥ 75 years old) with unilateral femoral neck fracture in our hospital from April 2015 to April 2020 were included in the study. Diagnostic criteria: patient's medical history, physical examination and X-ray. This study was approved by the Ethics Committee of Baodi Clinical College of Tianjin Medical University, and all patients signed informed consent.
Inclusion criteria :(1) femoral neck fracture (Garden type) ⅲ, ⅳ; (2) Body mass index (BMI) < 30 kg/m2; (3) There were no contraindications in preoperative evaluation; (4) Metabolic Equivalent of Task (MET)[5] score of daily living activities before the injury was ≥ 5 points; (5) The injury factor was falling down; (6) The patient consented to surgical treatment and gave informed consent to the study.
Exclusion criteria :(1) femoral neck fracture (Garden classification) type ⅰ and ⅱ; (2) BMI ≥ 30 kg/m2; (3) preoperative evaluation of patients who could not tolerate surgery; (4) MET score < 5 before the injury; (5) multiple fractures, pathological fractures or old fractures; (6) history of surgery for hip fractures; (7) other causes of injury than falls; (8) Patients who refused to participate in the study.
1.2 Clinical data
Patients were randomly divided into DAA group and MIPA group by random number method, with 98 patients in each group. Some of these patients had one or more internal medicine diseases, such as cardiovascular and cerebrovascular diseases, nervous system diseases and endocrine system diseases, etc. Their basic clinical information is shown in Table 1。
Table 1
basic information of the two groups
Variables
|
DAA(n = 98)
|
MIPA(n = 98)
|
P
|
Age
|
77.40 ± 1.73
|
77.47 ± 1.61
|
0.77
|
Gender (male, n/ %)
|
38/38.78
|
40/40.82
|
0.53
|
BMI (kg/m2)
|
24.45 ± 1.54
|
24.01 ± 1.71
|
0.06
|
Hypertension (n/ %)
|
40/40.82
|
42/42.86
|
0.77
|
Coronary heart disease (n/ %)
|
15/15.31
|
11/11.22
|
0.40
|
Cerebral infarction (n/ %)
|
22/22.45
|
18/18.37
|
0.48
|
Diabetes mellitus (n/ %)
|
41/41.84
|
30/30.61
|
0.10
|
COPD (n/ %)
|
10/10.20
|
11/ 11.22
|
0.82
|
Pre-injury MET score
|
5.12 ± 0.28
|
5.14 ± 0.30
|
0.68
|
DAA: direct anterior approach; MIPA: minimally invasive posterolateral approach; BMI: body mass index; COPD: chronic obstructive pulmonary disease; MET: metabolic equivalent of task. Statistical significance: P < 0.05.
|
1.3 Surgical methods
All patients underwent BHA by the same physician. All patients were anesthetized by lumbar anesthesia-epidural block anesthesia. Cefazolin sodium 1.0 was used 30 minutes before surgery to prevent infection, and tanexamic acid 1.0 g was intravenously administered 20 minutes before surgery to reduce intraoperative bleeding.
1.3.1 Operative procedures
DAA group: The patient is supine with a pad placed under the pelvis to hold the hip joint in the hyperextension position. A 7–8 cm incision was made at the distal end of the anterior superior iliac spine 3cm and 3cm outwards to enter the smith-petersen space. Ligate or cauterize the ascending branch of the lateral femoral artery. The fascia layer between the rectus femoris and tensor fascia lata was incised to expose the adipose tissue in front of the joint capsule. The inferior fascia of the rectus femoris was released to expose the anterior acetabulum space, and the ventral joint capsule was resected to reveal the fracture. Osteotomy was performed at about 1cm above the lesser trochanter and the femoral head was removed. The lower limb of the affected side was made into a “4” shape, and the femoral calcar was exposed. The articular capsule on the femoral calcar was removed, and the tissue behind was further released to fully expose the proximal femur. The medullary cavity was opened with a bone curette and shaped with an eccentric medullary file and implant femoral stem. Fitting prosthesis, the tensor fascia lata was sutured, and the incision was closed in layers.
MIPA group: Lateral decubitus position was taken, and the incision was made with the posterior edge of the greater trochanter. The incision was about 8-10cm along the gluteus maximus. The incision was 1/3 distal to the vertex of the greater trochanter and 2/3 proximal to the vertex. Blunt separation followed by incision of open fascia and exposure of gluteus maximus muscle, the insertion of the superior and inferior gemellus muscle is severed and the piriformis muscle is preserved, the gluteus maximus tendon and quadratus femoris are not incised. A partial incision of the external rotator muscle was made to expose the hip capsule and a cross incision was made to expose the femoral head, femoral neck and lesser trochanter. Femoral neck osteotomy, prosthesis installation, hip reduction, joint stability, range of motion and measurement of lower limb length. The external rotator muscle was repaired, the joint capsule was sutured and the wound was closed in layers。
1.3.2 Postoperative management
In both groups, 1.0 g trantranic acid was intravenously injected within 12h after surgery to reduce postoperative bleeding, analgesic pump with the same drugs was used to relieve postoperative pain within 24 h after surgery, and losolprofen sodium 60 mg was temporarily orally according to pain degree 24 h later. Both groups were treated with continuous ankle pump exercise, gradient pressure antithrombotic pump and subcutaneous injection of 5000 units (Qd) of low molecular heparin calcium to prevent deep vein thrombosis. The wound drainage tube was removed 24 h after surgery. Routine low-dose lung CT was performed 72h postoperatively to determine whether inflammation occurred in the lung. Stitches were removed 2 weeks after surgery. Patients are encouraged to sit and walk assisted by a walker as early as possible. 1 month later, walking was assisted by a cane, and gradually transitioned to unarmed walking.
1.4 Obvervational index
Operation duration (minutes), bleeding volume during operation(mL), degree of pain 24 hours after surgery (visual analogue scale[6], VAS). The time required for patients to keep sitting for 1h and independent walking after surgery(day). The ability of climbed up stairs, wearing socks and sitting 6 weeks and 2 years after surgery (measured by Harris scoring system[7]), and mortality after 2 years of operative.
1.5 Data statistics
SPSS 20.0 was used for statistical analysis. Comparison of the continuous variables between groups were performed by Student's t test and classification variables were performed by Fisher exact test. P < 0.05 was considered statistically significant.