Femoral intertrochanteric fracture is a common injury in the elderly, with a mean age of 70 years, 5-6 years higher than that of femoral neck fracture patients. Due to the rich blood flow in the trochanter, the fracture rarely does not heal, but it is very easy to occur hip inversion, and there are more complications caused by long-term bed rest in elderly patients, and the morbidity and mortality rate is 15%-20%.
Anatomy and anatomy and physiology
The trochanter of the femur is located between the greater trochanter and the lesser trochanter. The greater trochanter is rectangular in shape, in the upper posterior part of the femoral neck, superficial in position and palpable, and is a very obvious bony landmark. The superior part is the rotator fossa, and the greater trochanter is attached by the pear-shaped muscle, the gluteus medius, the internal and external closed foramen, the lateral femoral muscle, and the femoral square. The lesser trochanter is cone-shaped and is located on the superior posterior medial aspect of the femoral stem, to which the psoas muscle is attached. The hip capsule is attached to the intertrochanteric line. The femoral trochanter is mainly composed of cancellous bone. The lateral and medial rotator femoral arteries form an arterial ring at the base of the femoral neck in addition to the attachment of the intertrochanteric capsule, which emits four sets of supporting band arteries to supply the femoral trochanter and the femoral head.
Etiology and pathogenesis
When the lower extremity is suddenly twisted, falls or the large trochanter comes into direct contact with the ground, it is easy to cause fracture. Due to the compound stress of inversion and forward angulation on the ramus, it causes hip inversion deformity and small ramus butterfly fracture by inlaying pressure with the small ramus as the fulcrum, or small ramus avulsion fracture by sudden contraction of iliopsoas muscle. The bone of the ramus is brittle, so the fracture is often of the comminuted type.
Diagnostic points
Overview of diagnostic points
Most of the patients are elderly people, who have pain in the hip after the injury and cannot stand or walk. The shortening and external rotation deformity of the lower limb is obvious, and the above symptoms are mild in the case of non-displaced insertion fracture or stable fracture with less displacement. On examination, elevated greater trochanter of the affected side is seen, local swelling and bruising are visible, and local pressure pain is obvious. Percussion of the heel often causes severe pain in the affected area. In general, the local pain and swelling are more pronounced in intertrochanteric fractures than in femoral neck fractures, while the pressure point of the former is more often in the greater trochanter and the pressure point of the latter is more often outside and below the midpoint of the inguinal ligament. X-ray examination is often required to establish the diagnosis and to perform staging based on the radiographs.
Staging
There are various classifications based on the fracture site, the shape and direction of the fracture line, and the number of fracture fragments, etc. The staging system proposed by Evans and widely used is based on stable and unstable fracture staging (Figure 1), which in turn divides unstable fractures into those that can be stabilized after anatomic or subanatomic repositioning and those that are difficult to reestablish stability. In Evans type I fractures, the fracture line extends upward and outward from the lesser trochanter, and in type II anticline fractures, most of the fracture line extends outward and downward from the lesser trochanter; this type has a tendency to displace the femoral stem medially due to pulling by the adductor muscle.
Figure 1 Evans’ typing of intertrochanteric fracture
The Beijing Military General Hospital classifies intertrochanteric fractures into two categories: paracranial and retrotrochanteric fractures.
In the first category, the fracture line travels roughly parallel to the intertrochanteric line. In other words, it starts from above or slightly below the apex of the greater trochanter and travels obliquely inward and downward to reach the top of the lesser trochanter or slightly below it, which can be divided into four types (Figure 2).
Type I: a stable fracture that follows the intertrochanteric fracture without fracture displacement.
Type II: The fracture line reaches the upper edge of the lesser trochanter, where the bone cortex may be indented or not, and the fracture is displaced in an inversion dislocation.
Type IIIA: The fracture of the lesser trochanter becomes a free bone fragment, and the intertrochanteric fracture is displaced with an inversion deformity.
Type IIIB: The intertrochanteric fracture becomes a separate fracture block with a larger trochanteric fracture.
Type IV: In addition to the intertrochanteric fracture, each of the large and small trochanteric fractures becomes a separate fracture block, which may also be a comminuted fracture.
Type II: The fracture line is in the opposite direction of the intertrochanteric line, i.e., the fracture line travels obliquely from below the greater trochanter to the upper part of the lesser trochanter, and the lesser trochanter may also become a free bone fragment. In addition, the fracture line passes below the large and small ramus and becomes transverse, oblique, or serrated, and the fracture may also be mildly comminuted, as a subramus fracture.
Among the above types of fractures, in type I and type II, the fracture displacement and hip inversion deformity are not significant and are stable fractures, and the incidence of hip inversion is very low. In type II, those with cortical indentation of the upper edge of the small and medium ramus, type IIIA, IIIB, type IV and type II fractures, displacement and hip inversion deformity occur more often and are unstable, especially in type IIIA and type IV hip inversion has the highest incidence and is the most serious type of fracture with the highest incidence of hip inversion, accounting for about 80% of intertrochanteric fractures, of which unstable fractures account for the majority. Among the 169 cases of intertrochanteric fractures in Group 1 of Beijing Military General Hospital, 21 cases (12.4%) were retrotrochanteric fractures, 148 cases (87.6%) were partrochanteric fractures, and among the latter, 14 cases were type I, 36 cases were type II, 53 cases were type IIIA, 69 cases were type IIIB, 36 cases were type IV, and 90% were unstable fractures, especially type II, III, and IV were prone to hip inversion.
Figure 2 Fracture type of intertrochanteric fracture
Ⅰ, Ⅱ, ⅢA, ⅢB, and Ⅳ types are cis-columbar intertrochanteric fractures
Complications
The age of onset of intertrochanteric fracture is 7~8 years older than that of femoral neck fracture, and the complications are more and heavier, and the postoperative mortality rate is 5%~30%. The main reason for this is that patients with intertrochanteric fractures, with an average age of about 76 years, have poor health and many complications, e.g., Wang Fuquan reported that among 106 cases of intertrochanteric fractures, there were 40 cases (38%) of more than 3 coexisting diseases, with cardiovascular disease as the main coexisting disease, followed by diabetes mellitus and cerebrovascular disease, making anesthesia and surgery and postoperative management difficult.
1, prevention methods must strictly grasp the indications for surgery, should be selected according to the following criteria.
(1) Cardiac function Myocardial infarction, stable for at least 3 months; heart failure, stable for at least more than 6 months; ③ no serious arrhythmia, arrhythmia <6 times/min; ④ can walk upstairs before the injury.
(2) pulmonary function ① breath holding time > 30s; ② blowing wax distance > 50cm; ③ no coughing, asthma, shortness of breath; ④ arterial blood gas, PO2 > 60mmHg, PCO2 > 45mmHg, FVT1 < 70%.
(3) Hypertension: blood pressure <160/90mmHg, cerebral ischemia, cerebral embolism when the condition is stable for at least more than 6 months.
(4) Renal function: urine protein <++, urine volume >1ml/(kg・h), BUN <80mmol/L.
(5) Liver function transaminase not more than 1 times the normal value.
(6) Diabetes mellitus: fasting blood glucose <8.0mmol/L. This standard can successfully pass the operation in general cases.
(7) Choose the less invasive surgery and percutaneous penetrating needle internal fixation.
【Overview of treatment
Surgical treatment
1. Indications Stable or unstable fracture, older, and no obvious contraindications to surgery, the purpose of surgery, which allows the patient to leave bed early and reduce complications. In young patients, surgery can be used for good repositioning.
2.Surgical methods
(1)Femoral intertrochanteric fracture repositioning
①Reset criteria: the anterior-posterior image shows good contact with the medial cortical bone, and the lateral X-ray shows good contact with the posterior cortical bone.
②Resetting method: first, try to perform manual resetting, and after anesthesia, place the patient on a traction bed for specialized fractures, with the lower limb firmly fixed by a foot brace and a slightly external booth for traction along the long axis of the lower limb. If there is a crack or overlap on the medial or posterior side, further adjustment of traction or internal and external rotation of the affected limb position can be made to achieve standard repositioning. For comminuted fractures with posteriorly inclined distal fracture ends, sometimes the repositioning is more difficult, and if necessary, an incision and repositioning is performed, and the distal end of the fracture is corrected by lifting up using a bone holder.
(2) Internal fixation of intertrochanteric fracture of femur
(1) Principle: Stable internal fixation is available, and the degree of stability depends on the degree of osteoporosis, the type of fracture, the choice of internal fixation and the postoperative weight bearing of the affected limb.
(2) Types of internal fixation and evaluation
(2) Types of internal fixation and evaluation
Type 1: nail-plate type: typical representatives are Jewett nail plate and pressurized sliding screw.
A. Jewett plate: steel plate and nail combined together, with fixed neck stem angle (90°~135°), this fixed nail and plate as one, bending strength is large. Disadvantages: a. When the medial femoral cortex crushing instability, the stress is concentrated in the nail-plate combination, long time fatigue prone to plate bending or fracture; b. Fracture healing, fracture end insertion, due to no static force or power pressure effect, the nail tip through the femoral head, or loose, hip inversion; c. Because of the neck stem angle fixed, there are certain difficulties in operation, such as large anterior tilt angle, angle plate wing part of the penetration of the femoral neck front, anterior If the anterior tilt angle is small, a part of the angle plate wing penetrates the posterior part of the femoral neck; d. Even if the anterior tilt angle of the angle plate wing is correct, the angle plate is located in the middle of the femoral stem in front or behind, which will also make the angle plate wing penetrate from the neck. During the process of inserting the angular plate, the central axis rotates and the tail of the plate is not parallel to the femoral stem, and the plate cannot be fixed to the femoral stem.
B. Pressurized slip screw (DHS, CHS, Richard nail) (Figure 3): it uses a thicker screw instead of a triple-wing nail, the proximal end of the nail has a thick thread, the distal end has a sliding groove, and the lateral plate is changed to a plate with a sleeve, and the thick screw can slide on the sleeve. The sleeve steel plate has different specifications of neck stem angle, due to the internal fixator structure on the sliding screw and side steel plate to fix the steel plate to the distal and proximal ends of the fracture firmly, with strong bending strength, while allowing the embedded pressure between the fracture ends and restoring the medial stability. Complications: a. structurally ineffective anti-rotational effect, some authors confirmed the anti-rotational strength of 3.3 kg, it does not effectively prevent rotational displacement of the fracture end; b. large incision in the operation, more bleeding, long operation time; c. osteoporotic people, when the screw is located outside the head above, prone to screw cut out from the external upper femoral head.
Tames and Hatter review more than 10 literature in the last 20 years, nail plate type of fixed femoral intertrochanteric fracture, the occurrence of internal fixation failure rate, stable fracture is 15.9%, unstable fracture is 5% ~ 21%, Jenson et al. (1980), treated 1071 cases of intertrochanteric fracture with four types of internal fixation, a variety of internal fixation failure: Jewett nail plate occurred nail bending, fracture The incidence of fracture was 28.5%, hip inversion was 42.1%, and with compression sliding screws, head cutting, penetration into the acetabulum or penetration of the head occurred in 6%, and hip inversion in 6%.
Category 3: Multiple Searle pins or hollow screw fixation.
a. Multiple Searle’s pins: from four 3.5mm diameter Searle’s pins, the lower two pins enter from 13~14cm below the apex of the lateral femoral greater trochanter, through the medial femoral moment of the lesser trochanter, to the pressure bone beam of the femoral head, ending 0.5cm below the head; the other two pins enter 0.5cm below the femoral head at the base of the greater trochanter, through the pressure bone beam of the femoral head, the four pins enter at the point of the lateral femoral cortex near the diamond shape, in the middle of the head anterior-posterior cross distribution (Figure 5).
This method is characterized by strong resistance to compression, bending, and rotation, and good fixation. 80 cases of various type I intertrochanteric fractures were reported in our hospital using multiple S. pins for fixation, and 83.7% healed in situ after 2 to 3 weeks postoperatively, with no non-healing and internal fixation failure, and its shortcomings, prone to retreating pins, the reason for which, after 4 pins are fixed, there is always a pin either because of the proximity to the pivot point when the limb is weight-bearing, or because of the Self-locking angle is small, or due to osteoporosis and the maximum force, so one of the four needles easy to retreat, resulting in bursitis.
b, hollow screw: in order to overcome the disadvantages of multiple needle retreat needle, now more than three 6.4mm hollow screw instead. The fracture healing is fast. In 200 cases of various types of fractures treated in Beijing Military General Hospital, 90% of the fractures healed in situ, no non-healing and hip inversion, and 10% of the displacement healing was caused by poor technical fracture repositioning and poor needle distribution.