Knee fractures and Injuries

Patella #

Direct blow, sudden contraction of quadriceps or both

Check and document extensor mechanism: Ability to straight leg raise or if pain allows to straighten leg from flexed (more sensitive)

Above knee backslab Congenital bi-partite patella may mimic #. Skyline view if unsure.

If displaced or multifragmentary – Immediate referral to ortho If undisplaced and able to actively extend - Fracture clinic

Patella dislocation

Usually lateral after direct blow or sudden muscular contraction. May be recurrent.

Often reduced by time of assessment. Tenderness over medial quads attachment may indicate recent dislocation

Reduce with adequate analgesia & may require mild sedation: Fully extend knee then gentle pressure to lateral aspect of patella.

Cylinder cast or cricket pad splint

Fracture clinic - may require urgent MRI +/- repair of medial patello femoral ligament

Quadriceps or patellar tendon rupture

Abrupt muscular contraction +/- direct blow

Check and document extensor mechanism: Ability to straight leg raise or if pain allows to straighten leg from flexed (more sensitive).

If diagnosis is in question then USS is helpful.

Immediate referral to ortho - tendon must be re-attached surgically

Knee ligaments: Isolated medial collateral, lateral collateral, ACL or PCL injuries

Injury common in sports

Exclude gross instability and posterolateral corner injury (PLCI). Associations: haemarthrosis, capsular tear, meniscal tear or tibial spine #. X-Rays often normal

Often too painful to assess clinically at presentation. Crutches and analgesia

Must document distal N/V status

ED physio appointment at 5-7 days or referral to local physio via patient’s own GP

Immediate referral to ortho if gross instability. Refer associated injuries

as indicated e.g PLCI

Posterolateral corner injury (PLCI)

Sport/RTC/Fall. Hyperextension or anteromedial trauma

Often missed. Can be associated with knee ligament and nerve injury

Dial Test: Patient prone, External rotation of tibia with knee at 30° and 90°. +ve if > 10° difference

Immediate referral to ortho

Knee dislocation

Falls. RTA

Neurovascular injury: Consider CT angiogram

Must document neurovascular exam.

Immediate referral to ortho. Consider concurrent vascular

referral

Meniscus

Twisting injury. True locking. Bucket handle tear = springy block to full extension.

Often settles over 2-3 weeks but prone to recurrent locking or giving way

Crutches and analgesia

Fracture clinic If locked knee despite maximal analgesia – Immediate referral to ortho