| Overview |
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| Inspection |
- Skin
- Swelling
- Muscle atrophy
- normal quadriceps circumference
- 10 cm (VMO)
- 15 cm (quadriceps)
- Asymmetry
- Gait
- antalgia
- stride length
- muscle weakness
- Standing limb alignment
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| Palpation |
- Joint line tenderness
- Tenderness over soft tissue structures
- pes anserine bursae
- patellar tendon
- iliotibial band
- Point of maximal tenderness
- Effusion
- patella balloting
- milking
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| Range of Motion (patient supine) |
- Active and passive
- flexion/extension normal range
- 10° extension (recurvatum) to 130° flexion
- rotation varies with flexion
- in full extension, there is minimal rotation
- at 90° flexion, 45° ER and 30° IR
- abduction/adduction
- in full extension, essentially 0°
- at 30° flexion, a few degrees of passive motion possible
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| Neurovascular Exam |
- Sensation
- medial thigh - obturator
- anterior thigh - femoral
- posterolateral calf - sciatic
- dorsal foot - peroneal
- plantar foot - tibial
- Motor
- thigh adduction - obturator
- knee extension - femoral
- knee flexion - sciatic
- toe extension - peroneal
- toe flexion - tibial
- Vascular
- pulses
- popliteal
- dorsalis pedis
- posterior tibial
- ankle-brachial index
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ACL Injury
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- Large hemarthrosis
- Quadriceps avoidance gait (does not actively extend knee)
- Lachman's test
- most sensitive exam test
- grading
- A= firm endpoint, B= no endpoint
- Grade 1: <5 mm translation
- Grade 2 A/B: 5-10mm translation
- Grade 3 A/B: >10mm translation
- PCL tear may give "false" Lachman due to posterior subluxation
- Pivot shift
- extension to flexion: reduces at 20-30° of flexion
- patient must be completely relaxed (easier to elicit under anesthesia)
- mimics the actual giving way event
- KT-1000
- useful to quantify anterior laxity
- measured with knee in slight flexion and 10-30° externally rotation
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| PCL Injury |
- Posterior sag sign
- patient lies supine with hips and knees flexed to 90°, examiner supports ankles and observes for a posterior shift of the tibia as compared to the uninvolved knee
- Posterior drawer (at 90° flexion)
- with the knee at 90° of flexion, a posteriorly directed force is applied to the proximal tibia and posterior tibial translation is quantified
- the medial tibial plateau of a normal knee at rest is ~1 cm anterior to the medial femoral condyle
- most accurate maneuver for diagnosing PCL injury
- Quadriceps active test
- attempt to extend a knee flexed at 90° to elicit quadriceps contraction
- positive if anterior reduction of the tibia occurs relative to the femur
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| MCL Injury |
- Valgus instability = medial opening
- 30° only - isolated MCL
- 0° and 30° - combined MCL and ACL and/or PCL
- classification
- Grade I: 0-5 mm opening
- Grade II: 6-10 mm opening
- Grade III: 11-15 mm opening
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LCL Injury
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- Varus instability = lateral opening
- 30° only - isolated LCL
- 0° and 30° - combined LCL and ACL and/or PCL
- Varus opening and increased external tibial rotatory instability at 30° - combined LCL and posterolateral corner
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| PLC Injury |
- Gait
- varus thrust or hyperextension thrust
- Varus stress test
- varus laxity at 0° indicates both LCL & cruciate (ACL or PCL) injury
- varus laxity at 30° indicates LCL injury
- Dial test
- > 10° ER asymmetry at 30° only consistent with isolated PLC injury
- > 10° ER asymmetry at 30° & 90° consistent with PLC and PCL injury
- Posterolateral drawer test
- performed with the hip flexed 45°, knee flexed 80°, and foot ER 15°
- a combined posterior drawer and ER force is applied to the knee to assess for an increase in posterolateral translation (lateral tibia externally rotates relative to lateral femoral condyle)
- positive test at 30° is consistent with PLC injury
- positive test at 30° and 90° is consistent PLC and PCL injury
- Reversed pivot shift test
- with the knee positioned at 90°, ER and valgus forces are applied to tibia
- as the knee is extended, the tibia reduces with a palpable clunk
- tibia reduces from a posterior subluxed position at ~20° of flexion to a reduced position in full extension (reduction force from IT band transitioning from a flexor to an extensor of the knee)
- External rotation recurvatum test
- positive when the leg falls into ER and recurvatum when the lower extremity is suspended by the toes in a supine patient
- Peroneal nerve assessment
- injury present with altered sensation to foot dorsum and weak ankle dorsiflexion
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| Meniscus Injury |
- Joint line tenderness
- Effusion
- McMurray's test
- flex the knee and place a hand on medial side of knee, externally rotate the leg and bring the knee into extension
- a palpable pop or click is a positive test and can correlate with a medial meniscus tear
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| Patella Pathology |
- Large hemarthrosis
- absence of swelling supports ligamentous laxity and habitual dislocation mechanism
- Medial-sided tenderness (over MPFL)
- Increase in passive patellar translation
- measured in quadrants of translation (midline of patella is considered "0") and should be compared to contralateral side
- normal motion is <2 quadrants of patellar translation
- lateral translation of medial border of patella to lateral edge of trochlear groove is considered "2" quadrants and is an abnormal amount of translation
- Patellar apprehension
- Increased Q angle
- J sign
- excessive lateral translation in extension which "pops" into groove as the patella engages the trochlea early in flexion
- associated with patella alta
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