Management of Minimally Displaced Patellar Fractures with Hemarthrosis

Key Clinical Assessment Required

The American College of Radiology recommends verifying an intact extensor mechanism, where the patient must demonstrate active knee extension against gravity with no extension lag, for patients with minimally displaced patellar fractures and hemarthrosis 1, 2
Fracture fragments should have less than 2-3mm displacement and no articular step-off for conservative management to be considered, as per the Journal of the American College of Radiology 3
Hemodynamic stability is crucial, with no signs of compartment syndrome or vascular compromise, according to Anaesthesia 4, 5
Patient ability to comply with weight-bearing restrictions and immobilization instructions is necessary, as stated by the Journal of the American College of Radiology 1

The knee should be placed in full extension in a knee immobilizer, which should be worn at all times except for hygiene and skin checks, as recommended by Diabetes/Metabolism Research and Reviews 6, 7

Non-weight bearing or touch-down weight bearing with crutches initially is recommended, with consideration of assistive devices to reduce weight-bearing on the affected limb, according to Diabetes/Metabolism Research and Reviews and Journal of Thrombosis and Haemostasis 6, 8

The first follow-up should be within 5-7 days to reassess the extensor mechanism and check for displacement progression on repeat radiographs, as per the Journal of the American College of Radiology 1
Serial radiographs at 1-2 week intervals for the first 3-4 weeks are necessary to monitor for late displacement, according to the Journal of the American College of Radiology 3

Clinical decision rules, such as Ottawa/Pittsburgh, do not apply to patients with diabetes, paraplegia, or altered mental status, and these patients may require radiographs regardless of clinical findings, as stated by the Journal of the American College of Radiology 1, 9

Pharmacologic VTE prophylaxis with LMWH should be considered for lower extremity immobilization, particularly with risk factors present, according to the Journal of Thrombosis and Haemostasis 8