Knee Exam and Pathophysiology

Physical exam findings indicative of patellofemoral syndrome include:

-"Patellar squinting" - patella facing each other secondary to femoral anteversion -TTP along medial or lateral patellar facets -Positive patellar inhibition test and patellar grind test -Laterally tracking patella on extension/flexion of knee

How does patellofemoral syndrome present?

-Anterior knee pain that is worse when sitting in a tight space with knee flexed (Theater sign) -Pain walking down stairs or inclines, running or jumping -Popping or snapping sensations around the patella

Ober's Test

-Assesses for IT band syndrome -Patient in lateral position, support knee and flex to 90 degrees, then extend and abduct hip -Release knee support, failure of knee to adduct is a positive test -Also used for SHS ;)

Noble's test

-Assesses for IT band syndrome -Seated position with knee flexed to 90 degrees, apply pressure over the lateral femoral epicondyle and passively extend the knee -Lateral knee pain around 30 degrees of flexion is positive test

Apley's compression grind test

-Assesses for meniscal tear -In prone position, flex knee to 90 degrees, apply axial force along tibia and rotate tibia internally and externally -Pain is a positive test

McMurray's Test***

-Assesses for meniscal tear -With knee fully flexed, palpate joint line and apply axial force along tibia while externally rotating and extending the knee -Repeated with internal rotation -Pain, catching or painful clunk is a positive test

Bounce Test

-Assesses for meniscal tear -With leg in full extension, grasp heel and bounce the leg, gently forcing hyperextension -Pain is a positive test

Patellar grind test

-Assesses for patellofemoral syndrome -With knee extended, examiner pushes the patella posteriorly into the trochlear groove of the femur -Pain is a positive test

Patellar inhibition test

-Assesses for patellofemoral syndrome -With the knee extended, examiner pushes the superior aspect of the patella inferiorly into the trochlear groove as patient tightens quadriceps -Painful crepitus is a positive test

Exam findings consistent with ITBS

-Patients with foot pronation or varus alignment of knee more prone to ITBS -TTP over lateral femoral condyle 1-2cm above lateral joint line -Tight IT band on Ober's test -Pain elicited on Noble's test

Treatment of patellar instability

-Period of immobilization to allow healing prior to quadriceps strengthening exercises and knee sleeves -Recurrent episodes may need surgical correction (medial patellofemoral ligament repair or lateral retinacular release)

synovial plica

-Redundant fold of synovium found in the periphery of the joint, often along the medial side of the patellofemoral joint.

PE findings consistent with knee OA?

-Swelling or small effusion of the knee -Decreased ROM, particularly in flexion -Crepitus on ROM

PE findings consistent with a lateral meniscus injury

-TTP over joint line on affected side -Bounce test, McMurray's test, and Apley's Compression Grind test may all be positive -Small effusion may be positive

PE findings consistent with quadriceps tendonopathy

-TTP over the suprapatellar region at insertion of tendon -Quadriceps or hamstring tightness, malalignment of the patella may be present

PE findings consistent with Osgood-Schlatter Disease

-Tenderness and prominence of tibial tuberosity -May have associated tight hamstrings and quadriceps muscles

MCL stability test

-Tested with knee at 0 and 30 degrees flexion by applying a valgus force -Tenderness over MCL indicates a first degree injury -Laxity at 30 degrees denotes a second degree injury to MCL -Laxity at 0 degrees denotes a third degree injury to MCL

LCL stability test

-Tested with knee at 0 to 30 degrees of flexion by applying a varus force -Tenderness over LCL indicates a first degree injury -Laxity at 30 degrees denotes a second degree injury to LCL -Laxity at 0 degrees indicates a third degree injury to LCL

Osteochondrosis

-This is a general term for a group of developmental disorders that affect ossification centers and usually occur in adolescence. -failure of the hypertrophic zone to undergo mineralization and progression to bone formation; leads to retention, thickening and necrosis

How is IT band syndrome treated?

-Treatment aimed at IT band stretching and rehab -Occasionally corticosteroid injection can be considered

Treatment for prepatellar bursitis

-Treatment involves activity modification, compression and icing. -Aspiration can be used to relieve swelling and in chronic cases corticosteroid injections may be considered

Treatment of pes anserine bursitis

-Treatment usually conservative with icing, stretching (particularly hamstring) and more formal rehabilitation if needed -Corticosteroid injections can be considered

What is a bipartite patella, and how does it present?

-Two portions of the patella bone develop separately and are attached by only fibrous or cartilaginous tissue -Usually painless and incidental finding on knee XR's -Often confused with patella fracture -If there is an injury to the fibrous union, this area can be painful

About knee pain in the setting of hip OA

-Usually hip pain, but pain may be referred to the knee EXAM -decreased range of motion with pain on internal and external rotation TESTS & TREATMENT -XR's hip to make diagnosis -Always check hips and pelvis when working up knee arthritis -Usual arthritis treatments up to arthroplasty

(synovial) plica syndrome

-irritation, elargement, or inflammation of the plica -Intermittent or chronic pain over the area of the plica with repetitive knee activities -Occasionally a popping or catching sensation may be reported -May be exacerbated by direct trauma to the knee

baker's cyst

Knee effusion that herniates between the two heads of the gastrocnemius commonly associated with meniscal tears and OA

How does a quadriceps tendon rupture occur?

A quadriceps tear often occurs when there is a heavy load on the leg with the foot planted and the knee partially bent. Think of an awkward landing from a jump while playing basketball. The force of the landing is too much for the tendon and it tears. Tears can also be caused by falls, direct force to the front of the knee, and lacerations (cuts).

What is osteochondritis dissecans (OCD), and how does it present?

A type of osteochondral defect; a focal area (crack) of necrosis of the articular cartilage and the underlying subchondral bone -Vague knee pain with or without activity -May develop swelling related to activity -Sense of catching if a piece of bone has broken loose in the joint

Tests to diagnose knee OA

AP/LAT XR's of knee show joint space narrowing, periarticular osteophytes, subchondral cyst formation and sclerosis

What is Osgood-Schlatter Disease?

Osteochondrosis of the tibial tuberosity where patellar tendon attaches due to recurrent mechanical sterss on tibial tuberosity aphophysis during rapid growth

Retinaculum

Tissue on lateral and medial aspects of the patella which keep the patella centered on the midline of the knee

Treatment of Osgood-Schlatter Disease

Treatment includes hamstring and quadriceps stretching and activity modification to tolerance (sometimes extreme reductions in activity because too much stress on the growth plate)

Treatment of quadriceps tendonopathy

Treatment involves stretching, icing, rehabilitative program and modification of activities as needed

Treatment for a lateral meniscus injury

Usually arthroscopy

Tubercle

tubercle is a general term for a round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. On bones, they are usually eminences used for muscle connections. Larger tubercles are also known as tuberosities.

tibial tuberosity

where the patellar ligament attaches

How does ITBS present?

-Pain over lateral knee -May experience popping sensation -Running on sloped surfaces aggravates pain

Tests and treatment for patellar tendonopathy

-Clinical diagnosis, XR's may show irregularity at inferior patella -Treatment involves activity modification and functional rehabilitation program -Infrapatellar strap may be used to treat pain

What is fat pad syndrome and how does it present?

-Condition where the inferior fat pad of the patella gets pinched between the patella and the femoral condyle, occurring acutely with direct trauma or chronic with repetitive activity -Pain below the patella with activity. Worsened by prolonged standing or hyperextension.

Treatment for knee OA

-Conservative measures: weight loss, activity modification, low impact or aquatic exercises -Corticosteroid or viscosupplementation injections -Surgical treatment: arthroplasty

Physical exam findings consistent with patellar instability

-Dislocated patella over lateral femoral condyle -Swelling, effusion and TTP over patella (particularly medial side) -Positive apprehension test and hypermobility

How does a lateral meniscus injury present?

-Patient may complain of knee swelling and sharp pain on side of meniscus injury worsened by bending knee and squating -*May have locking or catching sensation, decreased on exertion

Patellar apprehension test

-Evaluates for patellar subluxation or dislocation -With knee extended, examiner pushes medially and laterally on patella in attempt to sublux the patella -Painful apprehension requesting to stop

What is patellar instability?

-Extensor mechanism problems range from true dislocation of patella to recurrent subluxation or instability leading to symptoms similar to patellofemoral syndrome -Similar to patellofemoral syndrome, but more acute

How does knee OA present?

-Gradually developing pain -Stiffness (decreased ROM), especially in the morning

How does a patella fracture present?

-History of trauma to the patella -Pain and swelling of anterior knee over patella

Differential diagnoses for lateral knee pain

-IT band syndrome -Lateral collateral ligament injury -Knee OA -Lateral meniscus injury -Proximal fibular fracture

How does a patellar tendon rupture present?

-Knee is usually quite painful and swollen -Patient often can not walk

Exam findings consistent with an LCL injury

-LCL laxity may be elicited with varus force on knee at 30 degrees or full extension -Laxity and pain in full extension denotes more severe ligamentous injury -TTP over region of LCL

tuberosity

-Large rounded projection; may be roughened -larger tubercles -protuberances

PE findings consistent with prepatellar bursitis

-Localized pain and swelling over the patella -Beware signs of infected bursa - erythema and warmth of skin

PE findings consistent with an MCL injury

-MCL laxity may be elicited with valgus force on knee at 30 degrees or full extension -Laxity and pain in full extension denotes more severe ligamentous injury -TTP over region of MCL

Tests (and findings) and treatments for patellofemoral syndrome

-Merchant view XR's of knees (lateral patellar tilt, lateral lateral patellar tilt) -Treatment consists of strengthening quadriceps and patellar bracing

How does a quadriceps tendon rupture present?

-Pain and swelling of knee -Inability to walk

How does an LCL injury present?

-Pain and swelling over lateral knee occurs after a varus force or twisting injury of the knee -Patient may report knee feels unstable with twisting and cutting

How does an MCL injury occur and present?

-Pain and swelling over medial knee occurs after a valgus force or twisting injury to the knee -Patient may report knee feels unstable with twisting or cutting

What PE tests are done to assess for a lateral meniscus injury?

Bounce Test, McMurray's Test, Apley's Compression Grind Test

How is IT band syndrome diagnosed?

Clinically

How is Osgood-Schlatter Disease diagnosed?

Clinically, but XR's may show irregularity of the tibial tuberosity

What is knee osteoarthritis?

Degenerative process of the joint cartilage in the knee

Patellar tendonopathy

Degenerative process of the patellar tendon where it inserts on inferior pole of patella

What is quadriceps tendonopathy?

Degenerative process of the quadriceps tendon at its insertion on the superior pole of the patella

How does pes anserine bursitis occur/present?

Direct trauma or overuse (medial hamstring muscle in swimmers, cyclists or runners) brings on localized pain

How does patellar instability present?

Dislocation due to traumatic event and usually remains dislocated until it is reduced (often by extending knee)

Femoral anteversion

Excessive anterior twist within upper femur. Most common feature is *W sitting* (sometimes results in miserable malalignment syndrome). Typically it spontaneously resolves by age 10-12

How does a patellar tendon rupture usually occur?

Falls. Direct impact to the front of the knee from a fall or other blow is a common cause of tears. Cuts are often associated with this type of injury. Jumping. The patellar tendon usually tears when the knee is bent and the foot planted, like when landing from a jump or jumping up.

What is a proximal fibular fracture?

Fracture of the proximal portion of the fibula from direct trauma or transmitted forces from the ankle

tibial plateau fracture

Fracture of tibial plateau usually occurs with direct trauma to knee, but can also be seen with axial compression from a fall or twisting injuries

What is ITBS?

ITBS is a pain syndrome caused by chronic irritation of IT band rubbing over bony prominence of lateral femoral condyle

Prepatellar bursitis

Inflammation and swelling superficial to patella usually caused by direct trauma or repetitive injury

What is pes anserine bursitis?

Irritation of pes anserine bursa at its location inferior and medial to anterior knee at area of insertion on tibia of sartorius, gracilis and semimembranosis tendons

Tests ordered for an LCL injury

MRI indicated to visualize ligament damage

Tests ordered for diagnosis of an MCL injury

MRI indicated to visualize ligament damage

Tests ordered to diagnose a lateral meniscus injury

MRI needed to visualize the meniscus

What is patellofemoral syndrome?

Most common etiology of anterior knee pain - malalignment of patella relative to femoral trochlea aggravated by activities that load the patellofemoral joint (running, jumping)

Where does a patellar tendon rupture most often occur?

Most commonly at attachment of tendon on inferior patella

Treatment for LCL injury

Most sprains and partial tears treated with crutches as needed and rehabilitation

Treatment of an MCL injury

Most sprains and partial tears treated with crutches as needed and rehabilitation

Which PE tests check for IT band syndrome?

Ober's and Noble's

Tear of a tendon can occur either at the _____ or the _____

Osteotendinous junction Midsubstance of tendon

How does prepatellar bursitis present?

Pain and swelling superficial to patella usually caused by direct trauma or repetitive injury

How does patellar tendonopathy present?

Pain in the area of the patellar tendon after or during activities that load the patellofemoral joint

How does quadriceps tendonopathy present?

Pain in the suprapatellar region with activities that use the quadriceps muscle

How does Osgood-Schlatter Disease present?

Pain over tibial tuberosity with activity and sports

How does a lateral meniscus injury occur?

Sudden meniscus tears often happen during sports. Players may squat and twist the knee, causing a tear. Direct contact, like a tackle, is sometimes involved. Older people are more likely to have degenerative meniscus tears. Cartilage weakens and wears thin over time. Aged, worn tissue is more prone to tears. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.

PE findings consistent with pes anserine bursitis

TTP of site of pes anserine bursa sometimes with swelling

PE findings indicative of patellar tendonopathy

TTP over patellar tendon usually over the insertion at inferior patella sometimes associated with thickening of the tendon

epicondyle

Raised area on or above a condyle

Menisci

Semilunar cartilaginous discs that sit between tibia and femur on medial and lateral sides of the knee

Sinding-Larsen-Johansen Syndrome

Similar to Osgood-Schlatter Disease, it is osteochondrosis of the inferior pole where the patellar tendon attaches presenting with pain associated with activity during a time of growth

Patellar squinting

patella face each other secondary to femoral anteversion

Theater sign

patient complains of mild/moderate anterior knee pain after prolonged sitting; indicative of patellofemoral syndrome

condyle

rounded articular projection

Patella function***

serves similar to a pulley in improving angle of pull of quads and redirecting forces, resulting in greater mechanical advantage in knee extension

Patellar facet

smooth depressions on posterior surface of patella; articulate with condyles of femur

An MCL injury is a ______

sprain or partial to full tear of the medial collateral ligament of the knee