A twenty-three-year-old man was involved in a single-vehicle motorcycle accident at highway speed in which he struck a tree lying in the roadway. At the scene of the accident, he had a Glasgow Coma Score of 15 with stable vital signs; he was transported to our American College of Surgeons Level-I Trauma Center by helicopter. Initial assessment revealed an open dislocation of the left knee and pelvic fracture on the left side. A Foley catheter was placed, and gross hematuria was revealed. The patient was able to wiggle the toes of the left lower extremity prior to intubation. He was intubated in the trauma bay for pain control and sedation during assessment of the leg wound.
The left lower extremity revealed a large laceration that extended from the midanterior part of the thigh distally to the tibial tubercle. The wound lay directly anterior over the knee joint, and the articular surface was visible (Fig. 1). This wound was contaminated with dirt and grass debris. The knee was grossly unstable with no ligamentous stability. Dorsalis pedis and posterior tibial pulses were palpable, and the foot had brisk capillary refill. The ankle-brachial index measurement on the left limb was 0.68; the measurement on the contralateral limb was 1.0. Irrigation of the wound was performed in the emergency room, and medication therapy with cefazolin and gentamicin was started; the patient also received a tetanus vaccine update.
Pelvic radiographs (Figs. 2-A, 2-B, and 2-C) demonstrated a pubic symphyseal diastasis of 5.2 cm and widening of the left sacroiliac joint of up to 9 mm. Radiographs of the knee (Fig. 3) revealed extensive subcutaneous and intra-articular gas but no fractures. Retrograde cystography demonstrated extraperitoneal bladder rupture with tracking of contrast material into the thigh (Fig. 4).
After a pelvic binder was placed, the patient was taken to the operating room. Prior to orthopaedic intervention, a vascular surgery team placed an inferior vena cava filter and performed a left lower-extremity angiogram. The angiogram showed no injury to the arterial supply. The inferior vena cava filter was placed prophylactically because of the diminished ankle-brachial index and extensive orthopaedic injuries.
In the operating room, the leg wound was debrided and irrigated with large volumes of fluid. During examination under anesthesia, it was noted that all ligamentous structures, including the patellar tendon, were compromised. A spanning external fixator was placed across the knee joint. The wound overlying the joint was closed with the exception of the most distal aspect of the wound, which could not be closed because of swelling and soft-tissue injury. A negative-pressure dressing was applied with continuous suction.
Over the next twenty-four hours, the patient continued to be anuric despite the placement of a Foley catheter. In addition, the wound vacuum-assisted closure (VAC) dressing over the left leg had an impressive output of serosanguineous fluid that continued to increase. Nursing documentation also indicated increased wound VAC output after administration of furosemide. The fluid was sent to the laboratory and found to have a creatinine concentration of 65.9 mg/dL. Therefore, the assumption was made that the urine that was draining from the traumatic bladder rupture was tracking down the leg and out the knee wound. This was likely exacerbated by the negative-pressure environment created by the wound VAC.
On the following day, the patient was taken back to the operating room for fixation of the pelvic ring injury and repeat irrigation and debridement of the leg wound. Intraoperative cultures were obtained from the leg wound, and vancomycin-impregnated beads and a tobramycin-loaded cement spacer were placed in the knee wound. Open reduction and internal fixation of the pelvic fracture was performed (Fig. 5). Since the pelvic wound likely communicated with the leg injury, the pelvic wound was irrigated with castile soap solution and 3 L of saline solution. Upon completion of the orthopaedic procedure, a urological surgery team performed primary closure of the bladder injury, with repair of two lacerations (measuring 3 cm and 2 cm) to the anterior portion of the bladder. After repair of the bladder injury, the output from the wound VAC markedly decreased.
Intraoperative culture specimens grew Pseudomonas aeruginosa, Morganella morganii, and Enterobacter aerogenes. Antibiotic coverage was changed to vancomycin, ciprofloxacin, and piperacillin-tazobactam. The patient underwent five additional debridements with antibiotic cement exchange over the next two weeks.
After obtaining negative culture specimens, a plastic surgeon performed a gastrocnemius flap coverage of the anterior portion of the knee. After this flap failed, a rectus abdominis free flap and split-thickness skin-grafting were performed. This wound eventually healed, and the patient was discharged on hospital day eighty-eight with a knee-spanning external fixator.
Four and one-half months after the injury and after multiple discussions, the patient underwent knee fusion with an intramedullary nail (Figs. 6-A, 6-B, and 6-C). Two weeks after this fusion, the patient developed an abscess under the flap area on the anteromedial portion of the thigh. Culture specimens revealed methicillin-resistant Staphylococcus aureus and pan-sensitive Pseudomonas aeruginosa. A two-week trial of antibiotic therapy failed, and the patient subsequently underwent irrigation and debridement of the wound with removal of implants and placement of an antibiotic cement spacer.
Over the next two years, the patient required three surgeries, including removal of the distal tibial locking bolt and fistula excision with repeat debridement as well as removal of the intramedullary nail per patient request. At the latest follow-up, the patient was doing well. He was satisfied with the fused knee and was able to walk with minimal difficulty and play golf. The wounds had healed, and there was no sign of infection.
Open dislocations of the knee are often a result of high-energy mechanisms. Open injuries account for 5% to 17% of knee dislocations3-7, with disruption of the soft tissues and ligamentous structures resulting in a grossly unstable joint. Most commonly, both cruciate ligaments, as well as at least one collateral ligament, are disrupted. Isolated cruciate injuries, however, have been reported in the literature8. Knee dislocations are frequently associated with meniscal, cartilage, and neurovascular injuries. The rate of nerve injury has been reported to be as high as 31%9, and that of vascular injury has been reported to be as high as 26%7 in open dislocations of the knee.
Even with appropriate treatment, complications following open dislocation of the knee are common. Infection has been reported as a very common occurrence. One study found an infection rate of 43%3. The use of immediate intravenous antibiotics demonstrated no substantial improvement in the infection rate9. This same study found the amputation rate to be 16%, with persistent infection being the most frequent indication.
In the setting of such high-energy mechanisms, skeletal and hollow-organ injuries often occur, as was the case with our patient. The soft tissue and organs housed within the pelvic cavity are at high risk of injury. Bladder injury occurs in up to 10% of cases of blunt trauma10. Pelvic fractures are found in >80% of cases of bladder rupture11-13. Blunt external trauma has been reported as the responsible cause in up to 94.5% of cases13.
Operative closure of extraperitoneal bladder ruptures has historically been the standard of care14. However, spontaneous closure of extraperitoneal bladder lacerations typically occurs within two weeks as long as there is no intrusion into the bladder lumen by debris or fractured bone15. In our patient, operative closure of the lacerated bladder was chosen for two reasons. First, the subcutaneous urine leak that communicated with the open knee dislocation made the use of a Foley catheter a futile effort, and the tract provided an avenue for infection. Second, operative fixation of the pubic diastasis was required; this procedure minimally exposes the bladder and decreases the risk of infection of the pelvic fracture16.
Urinomas should be regarded as noninfected hematomas. There is no evidence that routine antibiotics should be administered in a patient without signs of sepsis or urinary infection; however, drainage of the urinoma is recommended17. We were able to manage our patient’s urinoma via a urethral catheter and negative-pressure wound therapy applied to the knee arthrotomy. In other instances, percutaneous drainage of the urinoma may be necessary. Many urological surgeons recommend broad-spectrum antibiotics after bladder repair to resterilize the urinary tract17.
This case of multiple severe injuries in a polytrauma patient demonstrates the importance of a multidisciplinary approach. Coordination of the trauma general surgery, plastic surgery, urological surgery, and orthopaedic surgery teams was imperative. Open knee dislocations and traumatic bladder ruptures secondary to pelvic fractures are injuries that require acute management. Our patient, who sustained both injuries, was unique because he had an extraperitoneal urine leak communicating with the knee wound; to the best of our knowledge, this has not been previously described in the literature.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. One or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.