Synopsis
Differentiate patellar fracture from quadriceps and patellar tendon rupture, test active extension correctly, identify open or articular injury, and choose protection, early motion or surgical repair according to extensor continuity and congruity.
- Inspect anterior skin and wounds, palpate patella, quadriceps and patellar tendon and compare patellar height with the opposite knee.
- Test active straight-leg raise with the hip flexed slightly and knee supported; repeat after adequate analgesia when pain or haemarthrosis limits effort.
- Document distal pulses, peroneal and tibial nerve function and knee-dislocation signs because vascular injury is more urgent than extensor classification.
Key red flags
Absent distal pulses, cool foot, expanding popliteal swelling or new peroneal and tibial deficit after knee trauma requires immediate vascular and orthopaedic action.
Investigation priorities
Define patellar fracture, displacement and patellar height.
Management branches
Anterior knee trauma causes haemarthrosis, deformity or extension weakness.
- Perform trauma and distal neurovascular assessment, inspect wounds and support the knee in a comfortable extended position.
- Give analgesia, palpate the full extensor chain and test straight-leg raise, repeating after pain treatment when necessary.
Active extension is intact and fracture displacement and articular congruity are acceptable.
Key medicines
ParacetamolGive 1 g orally up to four times daily as required, with at least 4 hours between doses and no more than 4 g in 24 hours; reduce the maximum for low weight, frailty, malnutrition or liver risk.