orthopaedics: knee

Question 1

what does the knee joint consist of

Answer 1

medial and lateral compartments of tibiofemoral joint, patellofemoral joint

Question 2

what type of hyaline is inside the synovial knee joint

Answer 2

hyaline

Question 3

what part of the body has the thickest hyaline cartilage

Answer 3

retropatellar surface

Question 4

what are menisci

Answer 4

fibrocartilaginous cartilage inbetween tibiofemoral joint (x2), they are shock absorbers

Question 5

which meniscus is more mobile

Answer 5

lateral more mobile, medial fixed

Question 6

what is the function of the anterior cruciate ligament (ACL)

Answer 6

prevents tibia rotating

Question 7

what is the function of the posterior cruciate ligament (PCL)

Answer 7

prevents hyperextension and translation of the femur

Question 8

what do the medial and lateral collateral ligaments (MCL and LCL) do

Answer 8

MCL resist valgus forces, LCL resists varus forces

Question 9

what are early OA risk factors for the knee (5)

Answer 9

meniscal tears, ligament injuries (esp ACL), abnormal alignment, inflam arthritis, hobbies/ occupation

Question 10

what are the criteria for a knee replacement from OA

Answer 10

substantial pain and disability with no conservative treatment working

Question 11

what are risks of knee replacement

Answer 11

infection, thrombosis, unexplained pain after TKR

Question 12

who gets and what causes meniscal tears

Answer 12

young people playing sport - twisting force on loaded knee

Question 13

what are symptoms of meniscal tears

Answer 13

localised pain in medial or lateral joint line, effusion that develops NEXT day, pain, locking (cant straighten knee), positive steinmanns test

Question 14

what is more common medial or lateral meniscal tears

Answer 14

medial 10x more common

Question 15

what type of meniscal tears can occur

Answer 15

longitudinal, radial, oblique, horizontal, flap, degenerative

Question 16

what are bucket handle tears

Answer 16

large longitudinal tears where meniscal fragment flips out and is displaced

Question 17

what is a key feature of bucket handle tears

Answer 17

knee locks and cannot fully extend from mechanical obstruction - 15 degree extension

Question 18

how do you manage bucket handle tears

Answer 18

urgent arthroscopic repair

Question 19

what are degenerate meniscal tears

Answer 19

complex patterns

Question 20

who gets degenerate meniscal tears

Answer 20

elderly, common first stage of OA, spontaneous or mild injury

Question 21

how do you manage degenerate meniscal tears

Answer 21

steroid injection

Question 22

what feature of menisci leads to poor healing and what else contributes to poor healing

Answer 22

poor blood supply - elderly and older injuries

Question 23

what is gold standard investigations of meniscal tears

Answer 23

MRI

Question 24

what is the criteria for a meniscal repair

Answer 24

longitudinal repair in outer 1/3, recent, young patient (need 3/3)

Question 25

what is involved in a meniscal repair

Answer 25

stitching meniscus to it's bed, extensive rehab (90% not suitable)

Question 26

when would an arthroscopic partial meniscectomy be done

Answer 26

mechanical and acute tears

Question 27

what causes ACL ruptures

Answer 27

high rotational force: rotating body landing on planted foot - skiing, rugby, football

Question 28

what are symptoms and signs of ACL ruptures

Answer 28

pop usually heard/ felt, haemoarthrisis within an hour, deep pain in knee

Question 29

what is a symptom of chronic ACL rupture

Answer 29

when turning on planted foot gives way, tibia translocated forward

Question 30

what is favoured in ACL management

Answer 30

reconstruction > repair

Question 31

who are general ACL reconstruction candidates

Answer 31

professional sportsmen, failed phsyio, if injury from low impact injury

Question 32

what is involved in ACL reconstruction surgery

Answer 32

tendon graft passed through tibial and femoral tunnel, attached to normal ACL attachment sites on bone. then intense rehab

Question 33

describe PCL ruptures (4 points)

Answer 33

not common by itself, direct blow to ant tibia, bruising and knee pain, tibia translocated ant

Question 34

what are symptoms of MCL tears

Answer 34

laxity, pain on valgus stress, tenderness on origin and insertion of ligaments

Question 35

how do you manage acute MCL tears

Answer 35

normally good healing, hinged knee brace

Question 36

how do you manage chronic MCL tears

Answer 36

MCL tightening and reconstruction with a tendon graft

Question 37

when do LCL ruptures occur

Answer 37

uncommon alone - combo with PCL and ACL

Question 38

what is commonly injured in LCL ruptures

Answer 38

peroneal nerve

Question 39

what management is done in complete LCL tears

Answer 39

urgent surgery --> later reconstruction

Question 40

what causes a complete knee dislocation

Answer 40

high degree of forces can rupture all 4 ligaments (ACL, PCL, MCL, LCL)

Question 41

what are risks of total knee dislocation

Answer 41

thrombosis, popliteal artery damage, compartment syndrome

Question 42

how do you manage a total knee dislocation

Answer 42

emergency, X ray, vascular surgery assessment, stent or bypass, multi-ligament reconstruction

Question 43

what does the extensor knee mechanism consist of (5)

Answer 43

tibial tuberosity, patellar tendon, patella, quadriceps tendon, quadriceps muscles

Question 44

how to extensor mechanism ruptures occur

Answer 44

fast contractile forces eg weightlifting, fall, degenerative tendon

Question 45

which age group get patella tendon ruptures vs quadriceps tendon ruptures

Answer 45

``` patella = young < 40 quadriceps = old ```

Question 46

what are risk factors for extensor mechanism ruptures (5)

Answer 46

tendonitis, chronic steroid use, diabetes, RA, CKD

Question 47

what drugs can cause tendonitis

Answer 47

quinolone ABs eg ciprofloxacin

Question 48

how do you diagnose extensor mechanism ruptures

Answer 48

strait leg test, obvious gap, USS in overweight patient

Question 49

how do you manage extensor mechanism ruptures

Answer 49

surgery for complete/ large tears, reattachment of tendon to patella

Question 50

what is patellofemoral dysfunction

Answer 50

disorder of patellofemoral articulation

Question 51

what is patellofemoral dysfunction associated with (3)

Answer 51

chondromalacia patellae, adolescent ant knee pain, lateral patellar compression syndrome

Question 52

what are signs and symptoms of patellofemoral dysfunction

Answer 52

ant knee pain, worse downhill, grinding sensation, pseudo-locking after prolonged sitting

Question 53

how do you manage patellofemoral dysfunction

Answer 53

PHYSIO, taping, surgery as a last resort

Question 54

what can predispose patellar dislocations

Answer 54

ligament laxity, female, shallow groove, genu valum, femoral neck anteverion, high riding patella