Knee Ax and Rx

Question 1

SQs

Answer 1

• Clicking
• Locking (true vs pseudo) - meniscus, true locking associated with bucket handle tears
• Giving Way (true vs pseudo) - instability/rupture of ligaments
• Ascent/Descent of Stairs/Hill
• Any back or leg pain? (Is pain in a dermatomal region - pain in the knee can be referred from the back)
• Is there hip or ankle pain? (Knee pain can be referred from the hip or biomechanically affected by the ankle)
• Did the knee swell? How quickly? Where is the swelling? (Intra articular/ extra articular; immediate swelling usually indicates trauma within the knee such as ligament damage)
• Age – The following conditions are not exclusive to these age groups but a higher prevalence is noted in these populations (elderly – OA?, young – osgoods schlatters, middle aged- meniscal).

Question 2

Observations

Answer 2

General:
Erythema (Redness)
Haematoma (Bruising)
Oedema (Excessive build-up of fluid, normally feet/ankles)
Excessive hair growth
Oozing/weeping
Effusion (Swelling)
Bony Deformities
Atrophy/Hypertrophy

Observe in both standing and supine. Assess foot posture (Pes Planus/Pes Cavus) that could be altering joint position
Gait - trendelenburg, antalgic

Question 3

AROM and PROM

Answer 3

Flex – 0-135deg +

Ext – 0deg, +/- 5deg (hyperext)

Active:

• Muscle Control
• Pain

Passive:

• Resistance (end-feel)
• Pain
• Capsular pattern - flexion, extension

Question 4

Muscle tests

Answer 4

Power/strength:

• Gd I – V
• Through Range
• Quads – can test in supine (place your knee under there’s in approx 30deg flex) or sitting. Ensure testing IRQ and SLR.
• Hams – can test in supine (place your knee under there’s in approx 30deg flex) or in sitting

Control:

• Jerky
• Smooth

Length:

• Resistance
• End Feel
• Quads – Prone Knee Bend (PKB) or Thomas Test
• Hams (& Gastroc) – Popliteal Angle in supine

Stability:

• Non-Weight Bearing
  
  • Repeat IR flex/ext
• Weight Bearing
  
  • Single Leg Dip
  • Lunges

Question 5

Neurological testing

Answer 5

• Myotomes (look for weakness not pain)
  
  • L2: Hip flexion
  • L3: Knee extension
  • L4: Dorsiflexion
  • L5: Great toe extension
  • S1: Eversion, contract buttock, knee flexion
  • S2: Knee flexion, toe standing
• Reflexes
  
  • Knee Jerk (L3-4, Femoral Nerve)
  • Ankle Jerk (S1-2, Tibial Nerve)
• Dermatomes
• UMNL tests
  
  • ​Babinksi reflex
  • Clonus
  • Hoffman’s sign

Question 6

Special tests

Answer 6

• Valgus Stress Test
  
  • Tests: In 20-30deg flex – MCL
  • Positive Sign: excessive movement compared to opposite knee.
  • Procedure: Pt supine. Stabilise ankle and then apply medial stress to joint at 0deg and then 20-30deg.
• Varus Stress Test
  
  • Tests: In 20-30deg flex – LCL
  • Positive Sign: excessive movement compared to opposite knee.
  • Procedure: Pt supine. Stabilise ankle and then apply lateral stress to joint at 0deg and then 20-30deg.
• McMurray’s Test
  
  • Tests: Medial and lateral meniscus injury
  • Positive Sign: A snap or click
  • Procedure: Pt supine with knee completely flexed. To test the MEDIAL meniscus, Laterally rotate knee and passively extend to 90deg whilst palpating the joint line. To test the LATERAL meniscus repeat the test with the knee in medial rotation.
• Thessaly’s Test
  
  • ​Tests: Medial and lateral meniscus injury
  • Positive Sign: pain, catching, locking or apprehension
  • Procedure: Pt standing, knee flexed to 20deg. Hold pts hands for support and rotate pt left and right a few times
• Apley’s Test
  
  • ​Test: Meniscal and ligamentous injury
  • Positive Sign: If rotation plus distraction is more painful or shows increased rotation relative to the normal side = ligamentous; If the rotation plus compression is more painful or shows decreased rotation relative to the normal side = meniscal
  • Procedure: Pt in prone, knee flexed 90 deg. Laterally and medially rotate tibia in distraction then with compression
• Anterior Drawer Test
  
  • Tests: ACL
  • Positive Sign: tibia moves more than 6mm on the femur
  • Procedure: Patient supine, hips flexed to 45deg, knee flexed to 90deg. Stabilise the foot. Apply posteroanterior force to tibia.
• Lachman’s Test:
  
  • ​Tests: ACL
  • Positive Sign: exessive motion of tibia on femur
  • Procedure: Patient supine, knee flexed to 30deg. Apply posteroanterior force to tibia
• Posterior Drawer Test
  
  • Tests: PCL
  • Positive Sign: Excessive movement
  • Procedure: Pt supine with hips flexed to 45deg and knee flexed to 90deg. Stabilise foot. Apply anteroposterior force to tibia.

Question 7

Palpation

Answer 7

Palpate temperature, swelling, muscle tone, tissue mobility, and bony alignment.

You can palpate along the joint line, both medially and laterally, the patella and hamstring tendons and the patella.

Question 8

Functional assessment

Answer 8

Gait, squats, steps/stairs, hopping, running, jumping, single leg stand/squat