Author: Emily Rowe / Editor: Nick Tilbury / Codes: / Published: 23/03/2023
A 29-year-old male attends the Emergency Department (ED) with a 2-day history of left knee pain.
He was on his way home from the pub and walked across a pedestrian crossing as the lights changed from red to green. A car pulled off from a stationary position and drove into his left leg at around 5 mph.
The impact caused his knee to twist and move in a valgus direction and he then fell to the floor. He tells you he got back up again immediately and walked home. He denies any other injury.
The next day he noticed pain and swelling to the left knee, which has persisted despite rest, ice, elevation and regular over-the-counter analgesia. You take a SOCRATES history:
- Site- Medial aspect of anterior knee
- Onset- Sudden
- Character- Constant ache with sharp pain on weight-baring (WB)
- Radiation- Nil
- Associated symptoms- Swelling
- Timing – Constant
- Exacerbating/relieving factors Worse on weight-baring
- Severity- 5/10 at rest, 8/10 on weight-baring
He has borrowed a friends crutches to aid his mobility, and although he has no history of locking or giving way, he feels as though his knee is unstable.
On examination, you note a supra-patella effusion, and he is tender on palpation over the medial joint line.
He has good range-of-movement and can fully extend the knee, flex to 90 degrees and straight leg raise.
On stressing his MCL, there is some laxity but a defined end point. An x-ray is ordered (see below).
