Cortex - Adult orthopaedics pelvis and lower limb 3 (soft tissue injuries to the knee)

Question 1

What is the extensor mechanism of the knee comprised of ?

Answer 1

Constitutes of the tibial tuberosity, the patellar tendon, the patellar, the quadriceps tendon and the quadriceps muscles.

Question 2

Describe the mechanism of how patellar tendon or quadriceps tendon ruptures occur?

Answer 2

With rapid contractile force:

e.g. after lifting a heavy weight, after a fall

Or spontaneously in a severely degenerate tendon

Question 3

What is the difference in who patellar tendon ruptures and quadricep ruptures tend to occur in ?

Answer 3

patellar tendon ruptures tend to occur in people <40

quadriceps tendon ruptures tend to occur in >40

Question 4

What are some of the predisposing factors to patellor or quadricep tendon ruptures ?

Answer 4

History of tendonitis

• Chronic steroid use or abuse (body builders)
• Diabetes
• RA
• Chronic renal failure.
• Quinolone antibiotics (eg ciprofloxacin) can predispose to tendonitis/ruptures

Question 5

Should steroid injections be avoided in people with tendonitis of the extensor mechanism of the knee ?

Answer 5

Yes! it comes with a high risk of tendon rupture

Question 6

What test in your examination of acute knee injury would assess if the extensor mechanism of the knee is intact or if there is injury to it ?

Answer 6

SLR (straight leg raise)

Question 7

What is the results of the SLR when a patient has A disruption of the quadriceps tendon, patella, or patellar tendon e.g. talking about ruptures of the tendons

Answer 7

The patient may not be able to perform SLR

Question 8

If a patient has a partial tear of a tendon in the extensor mechanism of the knee what may the results of the SLR be ?

Answer 8

May have some extensor mechanism function (so may be able to perform it) but have reduced power e.g. when putting pressure on the SLR they may not be able to keep it up

Question 9

What is the treatment of tendon ruptures/ substantiale tears involving the extensor mechanism of the knee ?

Answer 9

Surgical with tendon to tendon repair (stitch torn tendon together) or reattachment of the tendon to the patella

Question 10

What are the signs of patellar and quariceps tendon ruputres ?

Answer 10

Inability to straight leg raise or weight bear.

A palpable gap in the patellar or quadriceps tendon (although this may be difficult to detect owing to swelling).

Change in height of the patella. (quadriceps tendon rupture patellar displaced inferiorly) (patellar tendon rupture, patellar displaced superiorly)

Question 11

What is patellofemoral dysfunction ?

Answer 11

It is described as an ill-defined ach producing anterior knee pain (this is a result of (mechanical and biochemical changes to the patellofemoral joint)

Question 12

What are the common signs/symptoms of patellofemoral dysfunction ?

Answer 12

• Anterior knee pain - worse going downhill
• Griniding or clicking sensation at the front of the knee
• Stiffness after prolonged sitting causing “pseudolocking”

Question 13

What is the treatment of patellofemoral dysfunction?

Answer 13

• 1st line - Physio to strengthen the muscles
• Adjunct - NSAID’s
• Adjunct - Patellar taping may help

Question 14

How does patellar dislocation commonly occur ?

Answer 14

By a direct blow or sudden twist of the knee

Question 15

What may be torn when the patellar dislocates ?

Answer 15

The patellofemoral ligament

Question 16

When the patellar dislocates what way does it usually displace ?

Answer 16

Laterally

Question 17

What type of swelling occurs following a patellar dislocation (same idea as what type of swelling occurs following an ACL rupture)

Answer 17

A lipo‐haemarthrosis occurs

Question 18

What is the treatment of patellar dislocation ?

Answer 18

• The patella usually reduces when leg is straightened or spontaneously, rarley needs manipulated back in
• After this physio is done to help strengthen the muscles

Question 19

What is myositis ossifficans ?

Answer 19

A condition where heterotopic ossification (bone forming outside the skeleton) occurs in muscles usually after an injury.

Question 20

What are the common examples of injury causing myositis ossificans ?

Answer 20

The injury may be innocuous and it can form after muscle contusion (“dead leg”), fractures (especially around the elbow) and dislocations (especially traumatic hip dislocation). Heterotopic ossification can also occur in the muscles and soft tissues after surgery including hip replacement particularly if it is a revision (re‐do) procedure.

Question 21

What is seen on X-ray in someone with myositis ossificans ?

Answer 21

Bony mass

Question 22

What is the treatment of myositis ossificans ?

Answer 22

The abnormal bone can be excised to try to relieve stiffness with high strength NSAIDs (Indomethacin) or radiotherapy used to help prevent recurrence.