Triage Summary: 45 year-old Mountie is brought in by his trusty steed, Horse, after hurting his left knee one-hour ago by jumping down out of the saddle in hot pursuit of a one, Mr. Whiplash.


HPI: 45 year-old mounted constable unable to bear weight on left leg due to knee pain since jumping off back of horse and still unable to bear weight. Landed with left leg straight and does not recall any rotation force at the time of landing. Denies LOC, head trauma or other pain.
PMHx: multiple incidences of accidental trauma, mostly related to equestrian-type activities.
PSurgHx: noncontributory
SocHx: works for Canadian law enforcement. No T/E/D.
Pertinent Physical Exam:
Primary Survey (ABCDE): no acute findings
Secondary Survey pertinent findings: No evidence of injury other than left knee tender to palpation just distal to joint space with mild effusion, skin intact without erythema, or calor. No frank crepitus with passive or active ROM, but both significantly limited by pain. Pain prohibits anterior or posterior drawer tests, nor any varus or valgus stress. DP and PT pulses intact distally bilaterally.
What injuries are you concerned about?

Proximal fibular fracture or tibial fracture
Patellar fracture less likely given no note of tenderness or mal-alignment
Left knee ligamentous or tendinous injuries in isolation or with associated bony pathology
What imaging if any would you order? What guides your decision?
Plain radiographs of the left knee. Consider adding a sunrise view and/or tunnel views to evaluate the patellofemoral joint and intercondylar notch.
This patient meets many of the Ottawa Knee Rules and therefore warrants imaging.
What are the components of the Ottawa Knee Rule? How does one apply it? How sensitive and specific is it?
Ottawa Knee Rule: if the answer is “yes” to any of the following questions and the injury occurred within the last seven days, get x-rays:

    Age ≥ 55 years
    Isolated tenderness of the patella
    Tenderness of the fibular head
    Unable to flex knee to 90 degrees
    Unable to bear weight both immediately and in ED (4 steps, limping is okay)

The sensitivity of this rule is 98.5% and the specificity is 48.6%.

Describe the Radiographic Findings
Mountie Fracture

“Figure 3: X-ray anteroposterior and lateral views showing…” cropped by DF Savage, courtesy of Mankar SH, Golhar AV, Shukla M, Badwaik PS, Faizan M, Kalkotwar via OPENi


Now that you have identified the injury, what is the immediate management and disposition?
This tibial plateau fracture is an operative injury, so after providing adequate analgesia to the patient, double-checking pulses and sensation, consult orthopedics and consider ordering a CT of the lower extremity to assist with operative planning. These patients are typically admitted for this operative management and for monitoring for possible complications.
What are the possible complications from this injury?
Vascular injury including to the popliteal artery which is anchored proximal to the knee
Compartment syndrome
The clinical scenario for this case was inspired by a childhood cartoon.
Bachmann, L. M., Haberzeth, S., Steurer, J., & ter Riet, G. The accuracy of the Ottawa knee rule to rule out knee fractures: a systematic review. Ann Intern Med [serial online]. 2004; 140: (2), 121-124.
Irish, C. B., & Bowe, C. T. Chapter 044. Knee Injuries. In A. B. Wolfson, R. L. Cloutier, G. W. Hendey, L. J. Ling, C. L. Rosen, & J. Schaider (Eds.), Harwood-Nuss’ Clinical Practice of Emergency
Medicine (6th ed.).

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