What Is Pelvic Reconstructive Surgery?

Pelvic fracture is a serious trauma, accounting for 1% to 3% of the total number of fractures, mostly caused by high-energy trauma, more than half with comorbidities or multiple injuries, the disability rate is as high as 50% to 60%. The most serious is traumatic hemorrhagic shock and pelvic organ injuries. Improper treatment has a very high mortality rate, which can reach 10.2%. According to statistics, 50% to 60% of pelvic fractures are caused by car accidents, 10% to 20% are caused by pedestrians, 10% to 20% are motorcycle injuries, 8% to 10% are fall injuries from heights, and 3% ~ 6% is a severe crush injury.

Basic Information

English name

pelvic fracture

Visiting department

orthopedics

Common locations

pelvis

Common causes

Caused by high energy trauma

Common symptoms

Local pain, swelling, subcutaneous ecchymosis in the perineum, groin, or waist, lower limb movements, and difficulty turning over

Causes of Pelvic Fractures

Mostly caused by high-energy trauma. According to statistics, 50% to 60% of pelvic fractures are caused by car accidents, 10% to 20% are caused by pedestrians, 10% to 20% are motorcycle injuries, 8% to 10% are fall injuries from heights, and 3% ~ 6% is a severe crush injury.

Classification of pelvic fractures

Pelvic fractures caused by low-energy trauma are mostly stable fractures, which mostly occur in elderly falls and low-speed car accidents, or avulsion of the anterior superior spine or ischial tuberosity of minors and athletes. The former is due to the sartorius muscle and the latter is due to The hamstring muscle is contracted forcefully, and the fractures caused by high-energy external force are mostly unstable fractures. The classification of pelvic fractures commonly used in the world is:

1.Young & Burgess classification

(1) Separation type (APC) is caused by anterior and posterior crush injuries, and the common pubic symphysis is separated. In severe cases, the anterior and posterior iliac ligament injury accounts for 21% of pelvic fractures. According to the severity of the fracture, it is divided into three types: I, II, III Subtypes

(2) Compression type (LC) is caused by lateral crush injury, which often causes patella fractures (lateral posterior compression) and hemilateral pelvic internal rotation (lateral anterior compression), accounting for 49% of pelvic fractures; There are three different subtypes: I, II, and III.

(3) Vertical (VS) shear external force injury, caused by vertical or oblique external force, often causes vertical or rotational instability to account for 6% of pelvic fractures;

(4) Mixed external force (CM) lateral crush injury and shear external force injury, resulting in anterior pelvic ring and anterior and posterior ligament injuries account for 14% of pelvic fractures.

The advantage of this classification is that it can help to judge the degree of injury and estimate the combined injury. It can guide rescue to determine the prognosis. According to literature statistics, the separation type has the most severe combined injury, the highest mortality rate, the compression type is second, and the vertical type is lower ; And the order of bleeding volume is separated type, vertical type, mixed type, compressed type.

2.Tile's / AO classification

(1) Type A is stable and slightly shifted;

(2) Type B is longitudinally stable, unstable in rotation, and the structure of the rear and pelvic floor is complete;

B1 crush injury before and after, external rotation, pubic symphysis> 2.5cm-anterior iliac ligament + sacrospinous ligament injury;

B2. Lateral crush injury, internal rotation;

B2.1 Lateral crush injury, ipsilateral type;

B2.2 Lateral crush injury, contralateral type;

B3 bilateral B-type injury;

(3) Type C rotation and longitudinal instability (longitudinal shear injury);

C1. Unilateral pelvis;

C1.1 Fracture of the sacrum;

C1.2 Dislocation of sacroiliac joint;

C1.3 Patella fracture;

C2. Bilateral pelvis;

C3. Complicated with acetabular fracture.

Clinical manifestations of pelvic fracture

1. The patient has a history of severe trauma, especially a traumatic history of pelvic compression.

2. Extensive pain, worsening when moving lower limbs or sitting. Local tenderness, congestion, rotation of the lower limbs, shortening deformity, bleeding from the urethra, swelling of the perineum can be seen.

3. The umbilical spine distance can be increased (separate fracture) or decreased (compression fracture); the posterior iliac spine can be increased (compression fracture), lowered (separation fracture), and moved up (vertical fracture).

4. Pelvic separation compression test, 4 sign, torsion test are positive, but it is prohibited to check patients with severe fractures.

Pelvic fracture examination

For most pelvic fractures, an upright X-ray can be used to determine the injury mechanism of the fracture and determine the initial rescue plan. Other imaging studies can help fracture classification and guide the final treatment.

1. X-ray inspection

(1) Routine and necessary basic examination of orthotopic pelvic radiography , 90% of pelvic fractures can be found by orthotopic radiography;

(2) When the pelvic entrance radiograph is taken, the bulb is tilted to the head by 40 °, which can better observe the metatarsal wing fracture, sacroiliac joint dislocation, anteroposterior and rotational displacement of the pelvis, pubic branch fracture, pubic symphysis separation, etc.

(3) When the pelvic exit film is taken, the bulb is tilted to the tail by 40 °, and it can be observed whether the sacrum and the sacrum are broken, and whether the pelvis is vertically displaced.

2.CT inspection

CT is the most accurate method for examining pelvic fractures. Once the patient's condition is stable, CT examination should be performed as soon as possible. For posterior pelvic injuries, especially patella fractures and sacroiliac joint injuries, CT examination is more accurate. CT examination should also be performed with acetabular fractures. CT three-dimensional reconstruction can more truly show the anatomical structure of the pelvis and the fractures. The positional relationship, forming a clear and realistic three-dimensional stereoscopic image, is of high value for judging the type of pelvic fracture and determining the treatment plan. CT can also show retroperitoneal and intraperitoneal bleeding.

3. Angiography

For the diagnosis and treatment of large vessel bleeding, rupture of large vessels can be found by angiography and bleeding can be controlled by embolizing blood vessels.

Pelvic fracture complications

Hemorrhagic shock

Rupture of anterior iliac venous plexus caused by hemorrhage at the fracture end and damage to the posterior structure is the main cause of shock. There are fewer ruptures of large blood vessels. Other causes include open wounds, pneumothorax, intra-abdominal hemorrhage, and long bone fractures.

2. retroperitoneal hematoma

The pelvic bones are mainly cancellous bones, and there are many pelvic wall muscles. There are many arterial plexus and venous plexus nearby. The blood supply is abundant. The gap between the pelvic cavity and the posterior skin membrane is composed of loose connective tissue. There is a huge space to accommodate bleeding, so Extensive bleeding can occur after a fracture. Huge retroperitoneal hematomas can spread to the kidney, submental, or mesentery. Patients often have shock, and may have symptoms of peritoneal irritation such as abdominal pain, bloating, weakened bowel sounds, and abdominal muscle tension. In order to distinguish from intra-abdominal bleeding, a diagnostic puncture may be performed, but the puncture should not be too deep, so as not to enter the retroperitoneal hematoma, which is mistaken for intra-abdominal bleeding. Therefore, it is necessary to observe carefully and check repeatedly.

3. Urinary tract or bladder damage

For patients with pelvic fractures, the possibility of lower urinary tract injury should always be considered. Urinary tract injuries are far more common than bladder injuries. Patients may have difficulty urinating and bleeding from the urethra. The incidence of urethral membrane injury was higher when bilateral pubic branch fractures and pubic symphysis were separated.

4. Rectal injury

Unless a pelvic fracture is accompanied by an open genital injury, rectal injury is not a common complication. Rectal rupture can cause diffuse peritonitis if it occurs above the peritoneal reflex; if it occurs below the reflex, perirectal infection can occur. Often an anaerobic infection.

5. Nerve injury

It usually occurs when the sacrum fractures. S1 and S2, which make up the lumbosacral nerve trunk, are most vulnerable to damage. The muscle strength of the gluteal muscles, hamstrings, and calf gastrocnemius muscles can be weakened, and the sensation loss in the back of the calf and the lateral part of the foot. Achilles tendon reflex disappears when the phrenic nerve is severe, but sphincter dysfunction rarely occurs. The prognosis is related to the degree of nerve injury. The prognosis of mild injury is good, and it is expected to recover within one year.

Pelvic Fracture Treatment

First aid

It mainly deals with shock and various life-threatening complications. Pelvic fractures often involve multiple injuries ranging from 33% to 72.7%, and the incidence of shock is as high as 30% to 60%. Severe pelvic fractures have a mortality rate of 25% to 39%, all caused by direct or indirect pelvic fracture bleeding. Therefore, the early treatment of pelvic fractures must follow the basic principles of advanced traumatic life support, first save lives, stabilize the vital signs, and then check and deal with pelvic fractures accordingly. Once the cause of pelvic fracture hemorrhage in shock is identified, it should be treated according to the rescue procedure for pelvic fractures. Early external fixation is very meaningful for the rescue of hemorrhagic shock caused by pelvic fractures. Effective external fixation methods include external fixator-fixed front ring, C-clamp-fixed rear ring. If there is no fixation device, it is simple Wrapping and fixing the pelvis with bed sheets, thoracoabdominal belts, etc. can also play a role in stabilizing the pelvis and hemostasis. If the blood pressure is still not maintained, open abdominal packing should be used to compress the hemostatic or angiographic arterial embolization.

2. Surgical treatment

(1) It is best to perform the operation within 7 days after the injury, but no later than 14 days, otherwise the difficulty of reduction will be greatly increased, and the incidence of malunion and non-union will also increase significantly.

(2) Select the treatment method according to the fracture classification . Type A pelvic fractures in the AO classification are stable fractures. They are generally treated conservatively. They rest in bed for 4 to 6 weeks and walk down early. Type B fractures are anterior ring injuries and only need to be performed. Anterior fixation; Type C fractures are posterior or anterior-posterior joint injuries and require pelvic ring anterior-posterior joint fixation.

(3) Indications for surgery Failure to close reduction; Residual displacement after external fixation; The pubic symphysis is greater than 2.5 cm or the pubic symphysis is interlocked; Vertically unstable fracture; Combined acetabular fracture; Severe rotational deformity Lead to lower limb rotation dysfunction; posterior pelvic ring structure damage displacement> 1cm, or pubic bone displacement with pelvic instability, shortening of the affected limb> 1.5cm; no perineal contaminated open rear injury. Fracture of the iliac pubic symphysis with femoral nerve and vascular injury, and open iliac fracture.

(4) surgical methods

1) Anterior fixation is used to fix the anterior ring instability, and it is often used for pubic symphysis and pubic branch fracture. The surgical indications are: a. Pubic symphysis greater than 2.5 cm; b. Nerve and vascular injuries; d. Open fracture of the pubic branch; e. Instability associated with posterior pelvis.

The main fixation methods are external fixation frame, pubic bone reconstruction steel plate, and hollow tension screw.

2) The posterior fixation is used to fix the instability of the posterior ring. It is often used for sacroiliac joint separation and metatarsal fracture. Surgical indications are: a. Vertical unstable fracture; b. Posterior pelvic ring injury displacement> 1cm; c. Open posterior injury without perineal contamination; d. Acetabular fracture.

The main fixation methods are: C-clamp, fixed with anterior iliac plate; fixed with posterior iliac bone bolt, iliac bone plate, iliac bone tension screw

(5) surgical approach and fixation

1) The front of the external fixing frame is fixed. External fixators are mostly used for temporary fixation of unstable pelvic fractures, or combined with other fixation methods to fix severely unstable pelvic fractures, and are not a routine final fixation option. The commonly used fixation method is the double nail method, that is, two thread nails are inserted into the iliac spine on both sides; when the condition is critical, one screw nail can also be inserted. The upper edge of the acetabulum). Before placing the nails, tighten the pelvis with a sheet or the like.

Key points of operation: A small 2cm incision behind the anterior superior ridge; Drill from front to back along the direction of the metatarsal wing, only through the lateral cortex; Insert the first 5mm screw; Insert the second screw , Located 2 to 3 cm behind the first one; Repeat steps 1 to 4 to place screw nails on the contralateral iliac spine; connect the short screw with a short rod; connect the short rod with a long rod;

The upper edge of the acetabulum should be placed backwards and pointed towards the sacroiliac joint. It should be operated under perspective to avoid driving into the acetabulum.

2) C-clamp is fixed behind. The sacroiliac joint is directly pressurized for the temporary fixation of unstable fractures in the rear. The operation is simple and can be performed in the emergency room. When the fracture is displaced, the fixation frame should be placed under the state of traction and internal rotation of the lower limbs.

The main points of the operation: a. The nail entry point is located at the intersection of the anterior superior iliac spine line and the longitudinal axis of the femoral shaft; b. Hammer the nail into the sacrum; c. Fasten the nail with a wrench and pressurize.

3) The pubic bone reconstruction plate is used for pubic symphysis separation and pubic branch fracture.

Surgical steps and points: The anatomy of the body surface is the combination of the umbilical cord, the anterior superior iliac spine, and the pubic bone. The incision is located on the two transverse fingers above the superior superior iliac spine and can be extended to the iliac spine to fix the combined iliac wing fracture or sacroiliac joint separation. The external oblique and rectus abdominis fascia were exposed, and the adipose tissue on the surface of the external oblique and rectus abdominis fascia was sharply separated up and down, revealing the abdominal white line. The avulsion of the rectus abdominis from the pubic symphysis is more common, and sometimes the rectus abdominis fascia is torn. Dissociate the rectus abdomen, protecting the peritoneum at the head and the bladder and neck at the tail. The rectus abdominis muscle was separated on the fingertips with an electric knife, and the bladder was protected with an intestinal plate after the rectus abdominis. The rectus abdominis muscle was pulled to the outside with a Hohmann hook, and the soft tissue of the superior branch of the pubic bone was cleaned by the electric knife to place a steel plate. Internal rotation of the lower limbs can partially reduce the pubic symphysis. Place the spot-shaped reduction forceps to reset the pubic symphysis. The reduction forceps are placed on the surface of the rectus abdominis muscle. A 5-hole reconstruction plate is selected, and pre-bending is performed on both ends of the plate, and the plate is also pre-curved laterally to fit the curvature of the pubic bone. The two screws in the middle are placed in the pubic symphysis, the lateral screws are in the pubic branch, and the screw closest to the pubic symphysis is eccentrically placed for compression. The first screw is not tightened, and the second screw in the opposite side is also tightened. Apply compression and tighten all screws to achieve anatomical reduction. In general, one steel plate is sufficient. If double steel plates are used to enhance stability, one plate is placed on top of the pubic symphysis and one is placed in front. Negative pressure drainage was performed behind the pubic symphysis, and only the edge of the rectus abdominis fascia was sutured instead of the entire layer of rectus abdominis, in order to avoid partial necrosis of the rectus abdominis, and the rectus abdominis fascia was sutured continuously. Negative pressure drainage was drawn from rectus abdominis.

4) The indications for anterior iliac plate fixation are dislocation of sacroiliac joint and fracture of iliac wing.

Advantages: simple exposure, direct visualization of the sacroiliac joint, easy anesthesia monitoring, extended incision fixation combined with pubic symphysis and anterior acetabular fracture, the disadvantage is that it cannot be used for zygomatic fracture, and sometimes it is difficult to reduce.

Surgical steps and points: Make an anterolateral incision along the iliac spine; Take care to avoid damage to the L5 nerve root located 1 to 1.5 cmd inside the sacroiliac joint when the sacroiliac joint is exposed; squeeze the pelvis by hand or hold the iliac bone with a screw Parallel traction reduction, reset forceps can be used to help reset when it is difficult to reset; Note that only one hole is allowed on the sacrum side plate, otherwise it is easy to damage the L5 nerve root; Two three-hole 4.5mm pressure steel plates are selected and placed at an angle of 90 degrees. The spine and pelvic marginal cortex are thicker; Parallel sacroiliac joints are driven into the metatarsal screws under direct vision.

5) Indications for posterior patella fixation include patella compression fracture, patella dislocation, patella fracture dislocation, etc. The advantage is that the exposure is direct and the phrenic nerve can be decompressed at the same time, but the approach has a higher incidence of skin necrosis, wound infection, and nerve damage.

Surgical steps and points: prone position, lateral or medial longitudinal incision of the posterior superior iliac spine; strip the gluteus maximus from the starting point of the posterior iliac spine; expose the sacral wings and gluteal muscles; gluteal blood vessels and nerves out of the sciatic Large notch, beware of injury when exposed; bilateral metatarsal fractures or severely crushed unstable fractures can be fixed with zygomatic plate, screws can be directly fixed to the strong posterior iliac spine, or zygomatic bolts can be used, but the fixing strength is slightly poor .

6) Percutaneous patella screw fixation

(6) Postoperative management DVT prevention of lower extremity deep venous thrombosis and pelvic fracture is 35% 50% higher and PE incidence is 2% 10%. If the patient has no obvious bleeding tendency, low molecular weight heparin can be given subcutaneously. , Otherwise you can use elastic socks, lower limb blood meter to prevent thrombosis. To prevent wound infection, intravenous broad-spectrum antibiotics are routinely used for 48 to 72 hours. Incisions and fixed wounds are more prone to infection and skin necrosis after posterior dissection. Care should be taken to observe. X-ray plain films of the normal, entrance and exit positions were taken after the operation. CT fixation of the stapes nails was needed to understand whether the screws had entered the sacral canal. Functional training of lung ventilation and ventilation as well as functional training of unloaded limbs should be started as soon as possible after functional training. Weight-bearing exercise The weight-bearing exercise of the healthy side limbs begins 3 days later. Partial weight-bearing begins 6 weeks after type B fractures, and part-weight-bearing begins 8 to 10 weeks after type C fractures. The complete weight-bearing is generally 12 weeks after surgery. Patients with bilateral pelvic instability injury started to be partially weighted on the lighter side 12 weeks after surgery. Removal of internal fixation The internal fixation of the pubic symphysis and sacroiliac joint can be removed in 6 to 12 months, but it is not necessary. Internal fixation in other parts generally does not need to be removed. One month, three months, six months, and twelve months after the re-examination, review the fracture healing and functional recovery.

(7) Surgical complications The incidence of postoperative infection is between 0% and 25%. Shear external force acting on the skin leads to the subcutaneous exfoliation of the skin around the pelvis, which significantly increases the postoperative infection rate. Postoperative incision and reduction and internal fixation can also increase the risk factors for infection. Injury and immobilization of pelvic veins of deep vein thrombosis are the main risk factors leading to thrombosis, and the incidence rate reported abroad is 35% 50%. It can occur in the pelvis or the lower extremities. Severe pulmonary embolism that can lead to pulmonary embolism occurs in 2% to 10%; the mortality rate is 0.5% to 2%. Nerve injury caused by sacroiliac joint dislocation due to traction and compressive injury during zygomatic fracture. It may also be caused by iatrogenic causes such as manual reduction, surgical exposure, and internal fixation. The incidence of pelvic fracture nerve injury is 10% to 15%. caused by improper treatment of malformation early. Manifestations include chronic pain, unequal leg length and sitting posture, lameness, low back pain, etc. Vertical displacement greater than 2.5 cm requires surgery. The incidence of non-union is about 3%, which mostly occurs in young patients under 35 years of age, and needs to be re-fixed and bone grafted.

References

1.HarmsJ, MelcherRP.PosteriorC1-C2FusionWithPolyaxialScrewandRodFixation.Spine, 2001, 26 (22): 2467-2471

2.HarryN. Herkowitz. Rothman-Simeone TheSpine, 6th Edition: Saunders, 2001: 120.