Slide 2 David, 21, apprentice plumber R leg injury during rugby
game (last pm) Hit from R side during tackle Impact on upper
outside 1/3 of leg (foot planted on ground) No previous Hx of knee
injuries No PMH of note Slide 3 Condyle Epicondyle Articulation
Tubercle Slide 4 Slide 5 Slide 6 Slide 7 Slide 8 Patellar ligament:
makes up the joint capsule on either side of the patella; maintains
patella alignment Collateral ligaments: contribute to stability
when standing (this is when they are taut) are also check ligaments
for flexed rotation (permit but limit rotation) Oblique popliteal
ligament: reinforces the joint capsule posteriorly Arcuate
popliteal ligament: strengthens the joint capsule posterolaterally
Anterior cruciate ligament: limits posterior rolling of the femoral
condyles on the tibial plateau during flexion; prevents posterior
displacement of the femur on the tibia and hyperextension of the
knee joint Posterior cruciate ligament: limits anterior rolling of
the femur on the tibial plateau during extension; also prevents
anterior displacement of the femur on the tibia and helps prevent
hyperflexion of the knee joint. Slide 9 ACL Medial collateral
ligament tear Slide 10 ACL: Non-contact change of direction;
hyperextension on landing from a jump or; direct valgus force PCL:
Contact injury to the ground or; clash of knees MCL: Contact valgus
injury Meniscal tears: Twisting on a planted foot Slide 11 Positive
swipe test Tenderness along the subcutaneous border of the fibula
(around the area he identifies as the impact site) Grade 3 laxity
with valgus stress Lachmans Test and anterior draw are inhibited by
pain from David Slide 12 Tell David he has injured a major knee
ligament and that the pain is from local bruising Knee splint +
crutches Refer for physiotherapy rehab and advice on weight
bearing/return to work+sport Slide 13 Look: Swelling, wasting,
spasm, scars, erythema, deformities Posture (leg length, foot
posture) Gait (walk 10 steps, in/out of chair, socks on/off) Feel:
Skin: temperature Quadriceps bulk (loss of tone/bulk, spasm,
tenderness, loss of continuity in extension) patella (tenderness,
thickened ligament, gaps, creptius, articular surface,
suprapatellar bursa, prepatellar bursa) Medial/lateral femoral
condyles and epicondyles Medial and lateral colateral ligaments
Medial and lateral joint lines Popliteal fossa (masses, pulse)
Slide 14 Knee effusion: is the swelling within joint or extrinsic
to joint? Patella tap: slide hand down thigh towards knee; push
down gently on patella Swipe/bulge test: stroke medial side
upwards; empty suprapatellar pouch; stroke lateral side downwards
Move: Flexion: 135 ; extension: 0-10 Observe patellar tracking
Special tests Patella apprehension: patella dislocation (knee
flexed 30 ; thumbs on medial border; lateral force) MCL/LCL stress
test: MCL/LCL tear (knee flexed 15-30 ; varus/valgus force to
distal tibia; repeat in full extension) Anterior draw test: ACL
tear (knee flexed; sit on foot; gently pull upper tibia forwards)
Lachmans test: ACL tear (knee slightly flexed; stabilise femur with
hand; apply pressure to posterior proximal tibia to move it
anteriorly) McMurrays test: medial/lateral meniscal tear (full
flexion; externally rotate foot + varus force Vs internally rotate
foot + valgus force; extend knee Slide 15 Source: Angus Hann With
Ligament testing you assess symptom response ( pain), laxity and
end feel. Acute spasm will guard the joint and give u a false
negative on Ligament testing. Inhibition affects strength. May be
unable to straight leg raise. Pain causes reflexive inhibition and
may cause knee to give way. Need to encourage patient to relax when
testing. Acute knee difficult. Slide 16 3. What could be done to
improve your confidence in the Lachman's and anterior draw test in
this case? Tell the patient to relax and practice more UptoDate:
The stability of the knee is assessed by varus and valgus stress
testing, the Lachman's test, and the anterior and posterior drawer
signs. The usefulness of these tests is limited if the patient's
muscles are not relaxed, as quadriceps contraction masks signs of
instability To improve confidence be Angus or Pete Slide 17 Rupture
patella loses its anchor patella moves inferiorly (towards foot)
unable to straighten knee A large sudden load may cause the entire
insertion to be compromised, leading to complete rupture.
Repetitive loading, particularly eccentric loads, causes
microfailure, usually at the muscle tendon junction. This
microfailure can result in partial tears Strain due to repetitive
functional overload, knees subjected to high levels of repeated
loading of extensor mechanism Slide 18 The following week you are
surprised to see David represent with a letter from the physio
agreeing with your diagnosis about the knee injury, but expressing
concern about the cause of the ongoing leg pain. Repeat clinical
examination shows a large effusion and there is laxity with
Lachman's test. You refer David for an x-ray which is shown below.
Slide 19 Fibula Head Neck Body Femortibial joint space Slide 20
Slide 21 Slide 22 Slide 23 hyper-extension lateral view allows
assessment of slope of intercondylar roof in relation to the tibial
plateau; Plain radiographs cannot be used to diagnose ACL tears. In
some cases, an avulsion fracture of the anterolateral tibial
plateau (ie, Segond fracture) is identified at the site of
attachment of the lateral capsular ligament. Slide 24 3. Review the
mechanism of injury and describe the sequence of events that
occurred to his knee. The impact was on the upper outside one third
of the leg while his foot was planted on the ground. running
landing from a jump Slide 25 Slide 26 1. What is the common
mechanism for ACL rupture? A blow to the side of the knee, which
can occur during a football tackle, may result in an ACL tear.
Coming to a quick stop, combined with a direction change while
running, pivoting, landing from a jump, or overextending the knee
joint (called hyperextended knee), also can cause injury to the
ACL. Basketball, football, soccer, and skiing are common causes of
ACL tears Slide 27 2. ACL ruptures in children are uncommon - why?
- What injury might a child sustain instead? The ACL infrequently
ruptures in children. Rather the bone on either end comes off.
Slide 28 3. What are the indications for imaging knee injuries?
Slide 29 4. What are the potential long term sequelae to an ACL
rupture which is not operated on in this age group? Depends on
activity level of patient Long term sequelae include instability,
particularly with pivoting type sports, but even walking
Instability causes damage to the menisci and the other
ligaments
