The overall incidence of lower urinary tract disruptions after fractures of the pelvic ring ranges from 7% to 25%.1,2,11,17,24,29,37 Conversely, pelvic ring fractures are present in 83% to 97% of patients with lower urinary tract disruptions after blunt trauma.5,18,20,29 The incidence of isolated bladder injury ranges from 6% to 11%, whereas the incidence of isolated urethral injuries ranges from 4% to 14% of patients with pelvic ring fractures.2,6,8,11,17,29 Urethral injuries are far more common in men than in women with the reported incidence as high as 25% after pelvic fracture.17,23,29,33 The rarity of female urethral injuries can be attributed to the short length of the female urethra, and its lack of attachment to the pubis. This increased mobility results in less shearing stresses on the urethra.4,16 A recent article, however, documented an incidence of urethral disruptions in 4.6% of female patients with pelvic fractures.30 Thus, the possibility of urethral injury in female patients should not be ignored. Ureteral injury has been associated with acetabular fractures but not with pelvic ring disruptions.2 Simultaneous bladder and urethral injury occurs in 0.5% to 2.5% of pelvic fractures.17,29,35 More importantly, as much as 35%17 of bladder disruptions may be associated with urethral disruption and as much as 41%17,24 of urethral disruptions may be complicated by bladder injury. This has an important implication in the workup of these injuries.
Although lower genitourinary injuries are usually manifest as disruption of the urethra and bladder, other variants have been described. In lateral compression injuries the urethra may become kinked, interrupting the flow of urine. Reduction of the pelvis may unkind the urethra reconstituting urinary outflow.19 Chronically malreduced lateral compression fractures may cause persistent hematuria. This results from prolonged compression of the bladder wall by the displaced arch with subsequent mucosal ulceration.7,10 Bladder herniation may occur in symphyseal disruptions resulting in the subcutaneous transposition of a portion of the bladder.7,10,28 A false negative cystogram may be obtained if the walls of the herniated bladder are closely opposed. Iatrogenic bladder injury may then occur during surgical exposure of the symphysis.7,10,28 The surgeon should be aware of this possibility, especially when exploring a chronic diastasis.
The literature shows the correlation between lower urologic injury and disruption of the anterior pelvic arch, especially bilateral pubic arch involvement.21,23,29 As the severity of the pelvic ring disruption increases, as evidenced by the amount of displacement, the extent of soft tissue injury (open versus closed fractures), and the number of rami fractures, the likelihood of lower urologic injury also increases.1,11,24 Unfortunately, few papers have applied the Tile Classification36 in their assessment of pelvic instability. Perhaps future studies will correlate the incidence of urologic injury with more current pelvic fracture classifications.
Bladder ruptures may be extraperitoneal or intraperitoneal. Extraperitoneal ruptures are more common and classically occur on the anterolateral aspect near the bladder neck.3,15 These ruptures were originally considered to be secondary to direct laceration by fracture fragments.12 However, Carroll and McAninch3 found that only 35% of the bladder ruptures in their series occurred in the area of the pelvic fracture. Similar findings were reported by Corriere and Sandler.15 These authors and others theorize that most extraperitoneal ruptures are the result of a bursting mechanism caused by acute compression of an empty bladder.9 In contrast, compression of a distended bladder results in an intraperitoneal perforation along the bladder dome.35 Importantly, extraperitoneal ruptures communicate with the retropubic space and in the presence of an indwelling catheter may contaminate the pelvic hematoma and the anterior arch. Intraperitoneal perforations result in intraabdominal extravasation of urine. Combined extra and intraperitoneal perforation occurs in as much as 12% of bladder ruptures.3 Local adjacent structures may also be injured creating more complex management decisions. The vagina, rectum, and perineum may be involved in the soft tissue injuries that accompany pelvic ring disruptions. Careful assessment, often in an operating room setting, is necessary to exclude such injuries. The presence of any of these injuries results in an open pelvis fracture requiring emergency treatment.
Urethral injuries are best discussed in the male and female separately. In the male, the urethra includes the prostatic, membranous, bulbous, and pendulous (penile) portions; the terms posterior and anterior urethra are also used to describe the male urethral anatomy. The posterior urethra include that portion proximal to and including the area of the external urinary sphincter; the anterior urethra includes the bulbous and penile portions.
Posterior urethral disruptions may occur above, at, or below the urogenital diaphragm; a classification system to describe the anatomy of urethral injuries based on retrograde urethrography has been described by Colapinto and McCallum.13 Most injuries seem to involve the region at and below the urogenital diaphragm. The prostate is firmly invested by surrounding fascial elements, involving condensations of the endopelvic fascia and levator muscle posteriorly. Experimental studies have shown that the prostatomembranous urethra and the urogenital diaphragm move as 1 unit resulting in a concentration of stresses at the bulbomembranous junction.13 Thus, shear forces occurring with pelvic ring disruption may tear the prostate away from the bulbomembranous urethra. Such injuries may be partial, with a bridge of intact urethra remaining, or may be complete, with complete loss of urethral continuity. In the female, urethral injury often occurs near the level of the bladder neck. Similarly, these injuries can be complete and circumferential, or partial.
The urinary continence mechanism involves the external (striated muscle) sphincter (at the level of the membranous urethra in the male and the midurethra in the female) and the bladder neck region (smooth muscle) in both the male and female. After posterior urethral disruption in the male, where there is extensive disruption and subsequent fibrosis of the urogenital diaphragm, the external sphincter may become rigid and fixed and lose its supple, muscular sphincteric qualities. In such cases, continence will depend on the bladder neck; if competent and functional, continence may be normal after urethral reconstruction, or only minimal stress incontinence may occur. If the bladder neck is incompetent, postoperative continence may be problematic and require further surgery. If cystographic studies suggest an open bladder neck, videourodynamic testing may be necessary before reconstruction to properly counsel the patient regarding the risk of postoperative continence. In addition to direct injury to the sphincteric muscular elements, sacral root or pelvic nerve injury can occur at the time of pelvic trauma which can also impact on ultimate continence. Such neurologic injury is more common with wide disruption of the sacroiliac joints.
Potency is a complex phenomenon that depends on intact neurovascular anatomy, hormonal milieu, and psychologic state. In the setting of pelvic ring disruption, erectile capability may be impaired as a result of injury to the cavernosal nerves. They can be traumatized along their course lateral to the rectum, along the posterolateral surface of the prostate, lateral to the membranous urethra, or more caudally near the crura of the corpora cavernosa beneath the inferior pubic rami. Alternatively, arterial or venous injury may occur because of laceration, contusion, avulsion or thrombosis of the arteries to the penis in the deep perineum or infrapubic region.
Blood at the external urethral meatus is considered the cardinal sign of a urethral injury.1,23 As the male urethra tears, the bulbocavernous muscle contracts, and blood is forced out the meatus.35 Blood may also be present at the urethral meatus in females with urethral disruptions, however, it is often erroneously attributed to vaginal bleeding. Further gynecologic investigation may identify a vaginal tear, while the urethral injury is missed. In Perry and Husmann's30 review of urethral injuries in females after pelvic fractures, 3 of 6 injuries were misdiagnosed because of an inadequate urologic evaluation. The authors emphasize that a meticulous vaginal examination be performed with inspection of the meatus and the vaginal canal. Other signs of urethral injury include perineal or genital swelling secondary to the extravasation of blood or urine from a torn urethra. In men, a high riding prostate may be palpated at rectal examination. The presence of any of the above physical findings is strongly suggestive of urethral injury, however, their absence does not rule out urethral disruption.1,17,24 Lowe et al23 reported that 57% of men in their series of urethral injuries secondary to pelvic fractures had none of the above physical findings. The presence of physical findings was directly related to the time interval since injury. Physical signs were rarely present with intervals less than 1 hour.23 The inability to void is also an unreliable indication of urethral injury. Patients with severe pelvic ring disruption may not void because of pain or shock from associated hemorrhage17,35 (23%-48% of patients present in shock). An attempt at voiding may be ill advised because in the presence of urethral disruption urine extravasation will occur.1 Difficulty passing a Foley catheter may also indicate urethral injury, however, the free passage of a catheter does not rule out a partial tear. More importantly, passage of a catheter before an adequate workup may convert a partial tear to a complete 1.1,23
Gross hematuria is the most important clinical finding in patients with a bladder rupture.1,3,18,21 Eighty-two percent to 97% of patients with pelvic fractures and bladder ruptures will have gross hematuria, however, there is no correlation between the degree of hematuria and the extent of the bladder injury.1 Furthermore, gross hematuria may also represent injury to the upper genitourinary tract. Microscopic hematuria is no longer considered an indication of urethral and/or bladder injury. Fallon et al17 found that only 1 in 77 patients with microscopic hematuria had significant lower urologic injury. Antoci and Shiff1 documented none in 120 patients. Both these series studied patients with pelvic fractures. Thus, microscopic hematuria alone is not an indication for lower urologic workup.1,3,17 Unrecognized bladder rupture may result in the inability to void or peritoneal signs or both.
Male patients with pelvic ring disruptions should undergo a retrograde urethrograph before placement of a Foley catheter.1,9,27 The patient should not be encouraged to void. It is essential to confirm the integrity of the urethra before placement of a Foley catheter to prevent conversion of a partial urethral tear into a complete one.1,24,27 Using a bulb syringe 30 to 40 cc of water soluble contrast medium is instilled into the urethra and xrays radiographs are obtained. If a Foley catheter has been prematurely inserted, a pericatheter urethrograph can be obtained by inserting an angiocatheter along side the Foley catheter to introduce contrast. Extravasation of contrast without filling of the bladder is diagnostic of a complete tear (Fig 1). An incomplete tear is shown by dye extravasation with partial filling of the bladder. If the urethrograph is normal, a Foley catheter is passed into the bladder and a retrograde cystogram is performed. Three hundred to 500 cc of dilute contrast is introduced into the bladder under gravity. Anteroposterior lateral, and oblique radiographs are obtained with the bladder fully distended and postdrainge.6,35 False negative cystograms may result if the bladder is not fully distended and if postdrainage films are omitted.3,6,9 Intraperitoneal bladder ruptures show a diffuse peritoneal extravasation or pooling of the contrast in dependent areas of the abdominal cavity (Fig 2).27 Extraperitoneal ruptures cystographically reveal a tear drop shaped bladder from compression by a pelvic hematoma while contrast extravasation is limited to the pelvis (Fig 3).35 As mentioned previously, urethral and bladder injuries may occur simultaneously. Thus, if a complete urethral tear is identified by urethrography, then a cystogram must be obtained via a suprapubic cystostomy. If a partial urethral tear is identified, a urologist may attempt a single gentle passage of a urethral catheter into the bladder. If successful, this is followed by a retrograde cystogram.1
Female patients with pelvic fractures pose a difficult diagnostic problem because retrograde urethrography is difficult to perform and rarely is helpful.16 In fact, many urologists suggest omitting this test in female patients. Thus, it is imperative that a thorough vaginal examination be performed in all female patients before Foley catheter placement. This should include a bimanual examination as well as inspection of the external genitalia, urethral meatus, and vaginal canal. Occasionally, an anterior vaginal wall laceration will communicate with a urethral tear. Blind insertion of a Foley catheter in this case can lead to inadvertent passage of the catheter into the vaginal canal.16 Suspected injury after a bimanual examination can be confirmed by urethroscopy, however, this may be difficult in the multiply injured patient.30 A urethral injury in a female patient may not be diagnosed until surgery. A case in which a partial urethral injury was not noted until the time of symphyseal plating was described. (verbal communication, P Tornetta III, MD, 1995). The patient had undergone successful Foley catheterization in the emergency room and had a normal retrograde cystogram. It must be emphasized that successful passage of a Foley catheter can occur in the presence of a partial urethral injury. It was emphasized that during open stabilization of the anterior arch, the surgeon should inspect the bladder and bladder neck region to exclude an occult injury. If a tear is found, the wound should be considered contaminated (especially in the presence of an indwelling Foley catheter) and use of an external fixator considered. (verbal communication, P Tornetta III, MD, 1995).
Excretory urography is reserved for the evaluation of the upper genitourinary tract. However, computed tomography (CT) scanning has been shown to be superior to intravenous pyelography in defining the presence and extent of renal injury.38 Mee et al26 prospectively compared retrograde cystography with routine CT scan in the evaluation of bladder injury. They found that routine abdominal pelvic CT scan is not a reliable method of evaluating bladder rupture. In their study intravenous contrast was used and the Foley catheter was clamped to ensure bladder filling. However, this technique did not distend the bladder sufficiently to achieve extravasation of dye through a bladder laceration. The author thought that extravasation could be enhanced by filling the bladder externally via a Foley catheter, as is done in conventional retrograde cystography.26 Workup of the multiply injured patient is facilitated with the CT scan because it is frequently used to evaluate the abdominal viscera and to delineate the type of pelvic fracture. Thus, 1 radiographic technique could be used to evaluate the pelvic fracture, abdomen, upper genitourinary tract, and bladder.26 As a result, retrograde CT cystograms are becoming the radiographic test of choice for bladder evaluation at many Level I Trauma Centers.
Urethroscopy and cystoscopy are rarely indicated in the acutely injured patient.7 Cystoscopy may be useful in those patients who have persistent gross hematuria despite normal urethrographs, cystograms, and upper genitourinary workups. Occasionally an occult bladder injury will be visualized in these cases.
Because many pelvic ring disruptions associated with lower urologic injury require surgical stabilization, it is imperative that the orthopaedist and urologist function as a team and not as independent practitioners. Of primary importance to the orthopaedist is the potential for infection after open stabilization of the anterior ring injury.
The potential for infection is greatest when contaminated urine communicates with the operative site. This situation exists if an extraperitoneal bladder rupture is treated with catheter drainage only. Indwelling catheters will allow colonization of the bladder within several days. Contaminated urine may then communicate with the anterior arch via the retropubic space through the unrepaired rupture site. Thus, all extraperitoneal bladder ruptures should be repaired to prevent contamination of the symphysis. Transvesical suturing of the bladder laceration through a high, vertical cystostomy is the preferable technique to avoid entering the retropubic hematoma and encountering troublesome bleeding. Simultaneous internal fixation of the anterior arch then can be performed safely.33 Kotkin and Koch22 reviewed nonoperative management of extraperitoneal ruptures and suggested that patients with multiple pelvic fractures were at risk for infection of the pelvic hematoma. They thought that primary repair would be preferable in this subset of patients.22 Most surgeons agree that conservative treatment of extraperitoneal bladder ruptures should be reserved for those ring disruptions not requiring stabilization.7 Intraperitoneal bladder ruptures do not communicate with the anterior arch, however, they must be repaired to prevent peritonitis.3,20 The arch then is fixed internally as a combined procedure through the same incision.
The type of urinary drainage used after bladder repair also may impact on the risk of postoperative infection. Urinary leakage around a suprapubic cystostomy can contaminate a Pfannensteil incision postoperatively, thus, many orthopaedists prefer urethral drainage. Maintenance of a clean operative site is facilitated by the distant site of the urethral catheter. In Cole and Bulhofner's14 series of acetabular fractures fixed via a modified Stoppa intrapelvic approach only 1 postoperative infection developed. The infection was attributed to the placement of a suprapubic catheter through the same anterior incision. In later cases, urethral catheters were used after bladder repairs and no infections developed.14 Routt et al32 stated in their paper on percutaneous iliosacral screw fixation that suprapubic cystostomy tubes never are used in their institution. All urinary diversion is accomplished via urethral catheters. Routt et al33 subsequently reported the successful treatment of 6 bladder ruptures with primary repair and urethral drainage. No infections developed in the simultaneously plated anterior arches. Matta,25 however, did not think a suprapubic catheter is a contraindication to anterior ring fixation and has recently reported the successful treatment of 6 patients with suprapubic drainage. A prospective controlled study comparing the 2 is needed to delineate which is the safest method of urinary drainage. If a suprapubic cystostomy is used it should be placed via a separate incision. Broad spectrum antibiotics and meticulous local care of the cystostomy site should also be used to prevent contamination of the surgical site.35
The potential for infection also exists in the presence of urethral disruptions, because the anterior arch may communicate with the urethral rupture site. As with unrepaired extraperitoneal bladder ruptures, an indwelling Foley catheter in the presence of an unrepaired urethral injury allows the external environment to communicate freely with the anterior arch. Primary realignment of the urethral tear over a Foley catheter without repair would seem to carry an increased risk of infection during symphyseal plating. This, however, has not been borne out by published data. Routt et al33 report only 1 postoperative infection in 11 patients with urethral disruptions treated with primary realignment over a Foley catheter. These patients underwent simultaneous internal anterior arch stabilization. Other surgeons favor external fixation when primary realignment without repair is used, because a urethral seal is not achieved. If primary realignment is used as the initial treatment, a fenestrated urethral catheter should be used to facilitate paraurethral drainage. Theoretically, primary urethral repair would create a seal and allow for urethral drainage without an increased risk of deep infection after internal fixation. In the polytraumatized patient, however, primary repair may not be possible.35 Alternatively, simple suprapubic urinary diversion (with delayed urethroplasty) avoids contamination of the paraurethral site allowing open anterior stabilization to be performed safely.25 As stated previously, meticulous local cystostomy care and antibiotics should be used to prevent urine contamination of the surgical incision.
In certain situations the risk of infection may be so great as to preclude open reduction and internal fixation of the anterior arch. In these cases the use of an external fixator is an attractive alternative. Untreated pelvic ring disruptions with contaminated suprapubic catheters are good candidates for external fixation. Nonoperatively treated extraperitoneal bladder ruptures may necessitate external stabilization of the associated anterior arch disruption for 2 to 3 weeks. At that time, if a cystogram reveals a healed rupture, the suprapubic catheter and fixator are removed. The anterior arch then can be plated with minimal risk. It must be emphasized, however, that the best treatment for extraperitoneal bladder ruptures is early primary repair with simultaneous anterior arch plating.
Lower urinary tract injuries may occur in as much as 25% of patients with pelvic ring disruptions. Urologic and orthopaedic complications may occur if these patients are not evaluated diligently in the emergency room. A multidisciplinary approach with close cooperation between the urologist and orthopaedist is essential for successful treatment. All bladder disruptions should be repaired primarily with simultaneous anterior arch plating through the same incision. Only extraperitoneal bladder ruptures with stable (not requiring fixation) pelvic fractures should be treated nonoperatively. Treatment of urethral injuries remains controversial. However, primary realignment over a temporary stent may be gaining favor over simple urinary diversion and primary repair. Future studies also may elucidate which mode of urinary drainage is associated with the lowest incidence of complications. Early recognition and aggressive treatment of urologic injury combined with pelvic ring stabilization will facilitate care of the multiply injured patients with a pelvic ring disruption.
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