Chronic Knee Injuries

Baker's Cyst pathology

herniation of the synovial cavity and accumulation of fluid in the popliteal space

S/sx of baker's cyst

Restricted knee flexion
Associated with meniscal tears and arthritic conditions

Pathology of bursitis

Repetitive trauma or friction over the bursa

S/sx of bursitis

Redness, localized swelling, increased warmth, and limited ROM

Pathology of IT band friction syndrome

Excessive friction (or compression) between IT band and lateral femoral condyle

MOI of IT band friction syndrome

Overuse

Predisposing factors of IT band friction syndrome

Genu valgum, excessive pronation, and leg length discrepancy

Pathology of patellar tendinitis

inflammation of patellar tendon

MOI of patellar tendinitis

overloading of the extensor mechanism

S/sx of patellar tendinitis

Crepitus
Pain with passive stretching
Pain with active knee extension
Chronic injury can weaken the tendon (possible rupture)

What are other common tendinopathies?

Hamstrings
Pes anserine
Patellar tendonitis

Pathology of anteromedial rotary instability

medial tibial plateau subluxes on the femur
Medial tibia rotates forward, lateral stays stable
**this is most common

MOI of anteromedial rotary instability

lateral rotation of the tibia with valgus stress

Structures that may also be affected with anteromedial rotary instability

ACL, MCL, posterior medial capsule, and medial meniscus

Pathology of anterolateral rotary instability

subluxation of lateral tibial plateau with anterior translation and medial rotation of the tibia on the femur
(lateral side of tibia rotates forward)

Structures that may also be affected with anterolateral rotary instability

ACL, LCL, posterior lateral capsule, PCL, and IT band

Pathology of posterolateral rotary instability

posterior subluxation of lateral tibial plateau
(lateral tibial plateau moves backwards)

MOI of posterolateral rotary instability

anterior blow to the tibia with the foot laterally rotated and the knee under varus stress

Structure that may also be affected with posterolateral rotary instability

Posterior lateral capsule, PCL, LCL, popliteus tendon

Pathology of posteromedial rotary instability

posterior subluxation of medial tibial plateau

MOI of posteromedial rotary instability

anterior blow to the tibia with the knee partially flexed under valgus stress and the foot medially rotated

Structures that may also be affected with posteromedial rotary instability

PCL, MCL, medial joint capsule

Pathology of patellofemoral pain syndrome (PFPS)

•Increased compressive forces between patella and femur
•Poor tracking of the patella

Risk factors of patellofemoral pain syndrome (PFPS)

•Anatomic alignment (genu valgum, patella Alta, and Q-angle >15-20)
•Decreased strength
•Altered movement patterns
•Poor tracking of patella

S/sx of patellofemoral pain syndrome (PFPS)

•tenderness over lateral facet
•dull ache in center of knee
•patellar compression will elicit pain
•activity exacerbates symptoms

Pathology of chondromalacia patella

softening, roughening, and eventual degeneration and defects on the articular surface of the patella

MOI of chondromalacia patella

direct and repetitive trauma, patellar malalignment, or previous trauma (dislocated/subluxed patella)

S/sx of chondromalacia patella

•general anterior knee pain
•crepitus
•deep knee flexion
•increased pain with patellofemoral compression

Pathology of plica syndrome

fold in the synovial membrane on the anterior aspect of the knee

S/sx of plica syndrome

•Most common site along the superior medial border of the patella
•Snapping or clicking as the knee moves into flexion
•Point tenderness

Pathology of Osgood-Schlatter Disease

Apophysitis occurring at tibial tuberosity

MOI of Osgood-Schlatter Disease

Repeated pulling on the patellar tendon

S/sx of Osgood-Schlatter Disease

Pain with kneeling, jumping, running
Common in adolescents
pain with active knee extension, active knee flexion, and passive flexion

What are the types of nerve and vascular injuries in the knee?

Peroneal nerve palsy (very superficial on lateral side)
Popliteal artery injury (emergency)
Popliteal nerve injury

Pathology of myositis ossificans

Bony formation where it should not occur

MOI of myositis ossificans

repetitive trauma (direct blows)

S/sx of myositis ossificans

Same as contusion
Hard chips of bone in the muscle belly feels like rice