Treatment of Acute Vertical Patellar Fracture with Hemarthrosis

Initial Assessment and Imaging

The American College of Radiology recommends obtaining anteroposterior and lateral knee radiographs as the initial imaging study, with an additional patellofemoral (sunrise) view specifically to evaluate the patellar fracture, for patients with focal patellar tenderness and joint effusion (hemarthrosis) meeting Ottawa rule criteria 1
The American College of Radiology suggests that these views are essential for any patient with focal patellar tenderness and joint effusion (hemarthrosis) meeting Ottawa rule criteria, with a strength of evidence based on clinical guidelines 1

The American College of Surgeons indicates that surgical fixation is indicated when fracture displacement exceeds 2-3mm, with a high strength of evidence based on clinical trials 2
The American College of Surgeons recommends that surgical fixation is indicated when any articular step-off is present, with a high strength of evidence based on clinical trials 2
The American College of Surgeons suggests that early definitive osteosynthesis within the first 24 hours reduces local and systemic complications in hemodynamically stable patients without severe visceral injuries, with a moderate strength of evidence based on observational studies 3
The American College of Surgeons recommends that the "PRompt Individualised Safe Management" (PRISM) approach prioritizes physiologic stability over immediate fracture fixation, with a low strength of evidence based on expert opinion 4

The American Society of Anesthesiologists recommends initiating antibiotic prophylaxis immediately according to surgical antibiotic prophylaxis guidelines for open fractures, with a high strength of evidence based on clinical trials 5
The American Society of Anesthesiologists suggests initiating early pharmacological thromboprophylaxis with low molecular weight heparin (LMWH) after hemorrhage control and hemostasis, particularly for lower extremity immobilization, with a moderate strength of evidence based on observational studies 5

The American College of Radiology warns against relying on clinical decision rules in special populations, such as patients with diabetes, paraplegia, or altered mental status, who require radiographs regardless of clinical findings, with a high strength of evidence based on clinical trials 1
The American College of Radiology recommends considering MRI if internal derangement (meniscal or ligamentous injury) is suspected after initial stabilization in the setting of hemarthrosis from trauma, with a moderate strength of evidence based on observational studies 1
The American College of Surgeons suggests avoiding delayed diagnosis of displacement by using serial radiographic follow-up in conservatively managed fractures, as late displacement can occur, with a low strength of evidence based on expert opinion 2