Acute knee injuries

Question 1

Assessment S/E

Answer 1

Was the injury contact or non-contact?
Could you play on? if so for how long?
Did you or anyone near you hear a crack or pop?
Was there swelling? Did the swelling appear immediately?

Have you subsequently had any clicking, popping or giving way in the knee?

• straight line
• twisting or changing direction

Question 2

Assessment O/E

Answer 2

- Quick function tests 
squat / gait 
- Lying supine observation - look and feel 
- Swipe test 
- Lachmann's 
- Sag test
-MCL Stress test
- LCL stress test 
- Patella apprehension 
- McMurrays

Question 3

ACL

Answer 3

• 72-90 of all ACL injuries are non-contact
  MOI - decelerating, pivoting or landing
  -rugby league - avoiding a tackle
• volley ball: landing

Key findings in S/E
sudden fall and their knee was painful
audible pop/crack and thought they had broken something
Blew up very quickly - indicative of haemarthrosis

Rx
- Treat swelling immediately with ice and compression

• start quads exercises even if just static
• Discuss with pts the need for x-ray and possible consultation with a knee surgeon

Prevention
- PEP - Prevent injury and Enhance Performancer trialled in US Women’s soccer team - reduced ACL incidence (decr non-contact ACL injury by 42%)
Warm up with emphasis on neuromuscular control, proprioception and agility

Question 4

MCL

Answer 4

Occurs due to valgus force
occurs in isolation or in conjunction with meniscal injury
Pain is always located medially
soft tissue swelling sometimes present but little or no effusion

Grade 2/3 may be braced in a hinged brace restricting lateral movement
rehab should have strong focus on knee strength

straight line activity for 4-6/52
gr 3 8/52

Question 5

PCL

Answer 5

less common than ACL and MCL
MOI - blow to the tibia or hyperextension injury
recovery is better w/o surgery
stability program incorporating VMO strength is important to reduce ongoing problems such as PFP

Question 6

LCL

Answer 6

*Uncommon* and rare in isolation 
Varus force MOI - generally contact
Differential Dx 
- lateral meniscus
- biceps fem tear/rupture 
posterolateral corner (often occurs with an ACL injury)

Question 7

Posterolateral corner

Answer 7

LCL 
posteriolateral capsule
Arcuate lig
popliteus tendon
can include biceps fem

Question 8

Meniscus

Answer 8

Common: Medial > lateral

Dx Hx
Palp
McMurrays
Confirm w/ MRI

Surgery is best option in large acute tears

Smaller/chronic tears - degenerative- may respond well w/ conservative approach

Question 9

Articular cartilage

Answer 9

Lining of the jt may be degenerative from acute injury causing a chondral defect
Often occur in conjunction with another injury
- ACL
Meniscus

Dx

• Hx
• Effusion
• Exclusion from other structures
• confirm w/ MRI

Rx
Manage swelling
strength and stability

Surgery
- chondroplasty
chondral cell implantation (not as common as prolonged process + non WB period

Question 10

Patella disclocation

Answer 10

MOI - running and twisting

Dx
- Hx + giving way
palp
patella apprehension test

Reduction with knee ext
- helps if you flex hip

Rx - taping, strength, stability

Question 11

Other injuries to consider

Answer 11

patella #
- splint/surgery

Tibial plateau #

• usually occurs w/ ACL and meniscus injuries
• +/- internal fixation
• Period of non-WB

Patella tendon rupture
- surgery