The acute swollen knee: diagnosis and management

Abstract

The acutely swollen knee is a common presentation of knee pathology in both primary care and the emergency department. The key to diagnosis and management is a thorough history and examination to determine the primary pathology, which includes inflammation, infection or a structural abnormality in the knee. The location of pain and tenderness can aid to localization of structural pathology even before radiological tests are requested, and indeed inform the investigations that should be carried out. Aspiration of an acutely swollen knee can aid diagnosis and help relieve pain. The management of the swollen knee depends on underlying pathology and can range from anti-inflammatory medication for inflammation to operative intervention for a structural abnormality.

Figure 1

Anatomically determining the causes of acutely swollen knee pathology (referred pain from the back, hip and nerves not included)

Figure 2

Flow diagram summarizing the sequential steps required to perform an adequate examination of the knee joint

Figure 3

Non-weight-bearing (left) and weight-bearing (WB) (right) views of the same knee demonstrating predominantly medial compartment OA, which is only apparent in the WB views

Figure 4

A skyline view of a left knee demonstrating patello-femoral OA

Figure 5

Indications for meniscal repair rather than resection

Figure 6

Flow chart of treatment pathways for OA

Picture 1

Demonstration of an anterior draw test

Picture 2

Demonstration of Lachmann's test