When we walk or run, a lot of effort is made by the knee for proper movement.

Imagine wearing a shoe with pointed heels and walking uncomfortably every day!

The walking style will become your habit but damage will be done to the cartilage in the knee.

Evaluation of Patients Presenting with Knee Pain

Dr. Jay Raj Sharma,Department of Orthopedic and Traumatology,

Lumbini Medical College and Teaching Hospital,Parvas, Palpa.

Knee pain is an extremely common complaint, and there are many causes.

Family physicians, Orthopedic surgeons and internist, Pediatricians and other doctors frequently encounter patients with knee pain.

PAIN CHARACTERISTICS• onset (rapid or insidious), • location (anterior, medial, lateral, or posterior knee), • duration, severity, and quality (e.g., dull, sharp, achy). • Aggravating and alleviating factors also need to be

identified.

MECHANICAL SYMPTOMSA history of locking episodes suggests a meniscal

tear.

A sensation of popping at the time of injury suggests ligamentous injury, probably complete rupture of a ligament (third-degree tear).

Episodes of giving way are consistent with some degree of knee instability and may indicate patellar subluxation or ligamentous rupture.

EFFUSIONRapid onset (within two hours) of a large, tense effusion

suggests rupture of the anterior cruciate ligament or fracture of the tibial plateau with resultant hemarthrosis,

Slower onset (24 to 36 hours) mild to moderate effusion is consistent with meniscal injury or ligamentous sprain.

Recurrent knee effusion after activity is consistent with meniscal injury.

Also effusion in other pathological disease entity.

MECHANISM OF INJURYThe patient should be questioned about specific

details of the injury-

If the patient sustained direct blow to the knee if the patient was decelerating or stopping suddenly if the patient was landing from a jump, if there was a twisting component to the injury, and if hyperextension occurred.

A direct blow to the knee can cause serious injury.Anterior force applied to the proximal tibia with the knee in flexion

(e.g., when the knee hits the dashboard in an automobile accident) can cause injury to the posterior cruciate ligament.

The medial collateral ligament is most commonly injured as a result of direct lateral force to the knee (e.g., clipping in football).

Quick stops and sharp cuts or turns create significant deceleration forces that can sprain or rupture the anterior cruciate ligament.

Hyperextension can result in injury to the anterior cruciate ligament or posterior cruciate ligament.

Sudden twisting or pivoting motions create shear forces that can injure the meniscus.

MEDICAL HISTORY• A history of knee injury or surgery .

• Previous attempts to treat knee pain, including the use of medications, supporting devices, and physical therapy.

• History of gout, pseudogout, rheumatoid arthritis, or

other degenerative joint disease and also past history of TB and other chronic illness.

Physical ExaminationINSPECTION AND PALPATION:Erythema, swelling, bruising, and discoloration.palpating and checking for pain, warmth, and effusion.

Point tenderness should be sought, particularly at the patella, tibial tubercle, patellar tendon, quadriceps tendon, anterolateral and anteromedial joint line, medial joint line, and lateral joint line.

Range of motion should be assessed by extending and flexing the knee as far as possible (normal range of motion: extension, zero degrees; flexion, 135 degrees)

Specific examinationPATELLOFEMORAL ASSESSMENT:An evaluation for effusion should be conducted with the

patient supine and the injured knee in extension. The suprapatellar pouch should be milked to determine

whether an effusion is presentThe presence of crepitus should be noted during palpation

of the patella.The quadriceps angle (Q angle): A Q angle greater than 15 degrees is a predisposing factor for

patellar subluxation

A patellar apprehension test:

CRUCIATE LIGAMENTSANTERIOR CRUCIATE LIGAMENT: Anterior drawer test: the patient assumes a supine position with the injured knee

flexed to 90 degrees. The examiner fixes the patient's foot in slight external rotation (by sitting on the foot) and then places thumbs at the tibial tubercle and fingers at the posterior calf. With the patient's hamstring muscles relaxed, the examiner pulls anteriorly and assesses anterior displacement of the tibia (anterior drawer sign).

The Lachman test:

The test is performed with the patient in a supine position and the injured knee flexed to 30 degrees. The examiner stabilizes the distal femur with one hand, grasps the proximal tibia in the other hand, and then attempts to sublux the tibia anteriorly. Lack of a clear end point indicates a positive Lachman test.

POSTERIOR CRUCIATE LIGAMENT Posterior drawer test: The patient assumes a supine position with knees flexed to

90 degrees. While standing at the side of the examination table, the examiner looks for posterior displacement of the tibia (posterior sag sign).

Next, the examiner fixes the patient's foot in neutral rotation (by sitting on the foot), positions thumbs at the tibial tubercle, and places fingers at the posterior calf. The examiner then pushes posteriorly and assesses for posterior displacement of the tibia.

COLLATERAL LIGAMENTSMEDIAL COLLATERAL LIGAMENT:The valgus stress test is performed with the patient's leg

slightly abducted. The examiner places one hand at the lateral aspect of the knee joint and the other hand at the medial aspect of the distal tibia. Next, valgus stress is applied to the knee at both zero degrees (full extension) and 30 degrees of flexion. With the knee at zero degrees (i.e., in full extension), the posterior cruciate ligament and the articulation of the femoral condyles with the tibial plateau should stabilize the knee; with the knee at 30 degrees of flexion, application of valgus stress assesses the laxity or integrity of the medial collateral ligament.

LATERAL COLLATERAL LIGAMENT

Varus stress test, the examiner places one hand at the

medial aspect of the patient's knee and the other hand at the lateral aspect of the distal fibula. Next, varus stress is applied to the knee, first at full extension (i.e., zero degrees), then with the knee flexed to 30 degrees. A firm end point indicates that the collateral ligament is intact, whereas a soft or absent end point indicates complete rupture (third-degree tear) of the ligament.

MENISCIUsually demonstrate tenderness at the joint line.The McMurray test is performed with the patient lying

supine.The test is performed with the patient supine and the knee

flexed to 90 degrees. To test the medial meniscus, the examiner grasps the patient's heel with one hand to hold the tibia in external rotation, with the thumb at the lateral joint line, the fingers at the medial joint line. The examiner flexes the patient's knee maximally to impinge the posterior horn of the meniscus against the medial femoral condyle.

A positive test produces a thud or a click, or causes pain in a reproducible portion of the range of motion

RadiographsAnteroposterior view, Lateral view, and

Merchant's view (for the patellofemoral joint).Notch or tunnel view (posteroanterior view with the knee flexed

to 40 to 50 degrees) for teenage patients who report chronic knee pain and recurrent knee effusion to detect radiolucencies of the femoral condyles (most commonly the medial femoral condyle), which indicate the presence of osteochondritis dissecans.

Inspect for signs of fracture, particularly involving the patella, tibial plateau, tibial spines, proximal fibula, and femoral condyles.

Standing weight-bearing radiographs should be obtained if osteoarthritis is suspected,

Arthroscopy

Laboratory Studies Complete blood count with differential and an erythrocyte sedimentation rate (ESR),Arthrocentesis- The joint fluid should be sent to a

laboratory for a cell count with differential, glucose and protein measurements, bacterial culture and sensitivity.

Rheumatoid FactorSr. Uric acid

Take Home Message

Accurate diagnosis requires:1. knowledge of knee anatomy, 2. common pain patterns in knee injuries, and3. features of frequently encountered causes of knee pain,

as well as specific physical examination skills.

The history should include 1. characteristics of the patient's pain, 2. mechanical symptoms (locking, popping, giving way), 3. joint effusion (timing, amount, recurrence), and4. mechanism of injury.

The physical examination should include:

1. careful inspection of the knee, 2. palpation for point tenderness, assessment of

joint effusion, range-of-motion testing, 3. evaluation of ligaments for injury or laxity,

and assessment of the menisci.

Evaluation of Patients Presenting with Knee Pain:

Differential Diagnosis

Differential Diagnosis of Knee Pain: by Age Group

Children and adolescents Young Adults Older adultsPatellar subluxation Patellofemoral pain syndrome

(chondromalacia patellae)Osteoarthritis

Tibial apophysitis (Osgood-Schlatter lesion) Medial plica syndrome

Crystal-induced inflammatory arthropathy: gout, pseudogout

Jumper’s knee (patellar tendonitis)Pes anserine bursitis Popliteal cyst (Baker’s cyst)

Referred pain: slipped capital femoral epiphysis, perthes disease, hip fracture

Trauma: ligamentous sprains (anterior cruciate, medial collateral, lateral

collateral), meniscal tear, Fractures, muscle strains

Metastatic Cancer

Osteochondritis dissecans Inflammatory arthropathy: rheumatoid arthritis, Reiter’s syndrome, Pigmented

Villanodular Synovitis

Juvenile Rheumatoid Arthritis Tendonitis (quadriceps, Patellar tendon, etc)

Trauma: ligamentous sprains (anterior cruciate, medial collateral, lateral collateral), meniscal tear, Fractures to include Epiphyseal Fracture , muscle strains

Septic arthritis

Stress Fracture/Stress Reaction

Referred Pain: Neurogenic, Hip and leg pathology

Common Knee pain by Anatomic Site:Anterior knee pain • Patellar subluxation or dislocation • Tibial apophysitis (Osgood-Schlatter lesion) • Jumper's knee (patellar tendonitis) • Patellofemoral pain syndrome (chondromalacia

patellae) Medial knee pain • Medial collateral ligament sprain • Medial meniscal tear • Pes anserine bursitis • Medial plica syndrome

Lateral knee pain • Lateral collateral ligament sprain • Lateral meniscal tear • Iliotibial band tendonitis

Posterior knee pain • Popliteal cyst (Baker's cyst) • Posterior cruciate ligament injury

D/d according to Mechanism of Injury:Traumatic:

• Fracture of Femur, Tibia, Fibula, Patella• Ligamentous Sprain (ACL, MCL, LCL, PCL)• Mensical Tear• Patellar subluxation/dislocation• Muscle Strain• Osteochodral fracture

Atraumatic:• Osteoarthrits• Rheumatoid or other inflammatory Arthritis (Pigmented

villonodular arthritis, gout, reiters syndrome)• Septic Arthrits• Popliteal cyst• Stress Fractures/reactions (tibial plateau & shaft, femur,

patella)• Tendonitis• Patellofemoral Syndrome• Medial plica syndrome• Referred pain (hip OA, Lumbar radicular sx)• Metastatic cancer

Common Knee problem in Children and Adolescents

PATELLAR SUBLUXATION:

Most likely diagnosis in a teenage girl who presents with giving-way episodes of the knee.

Increased quadriceps angle (Q angle), usually greater than 15 degrees.

Patellar apprehension is elicited. *

TIBIAL APOPHYSITIS:

A teenage boy with anterior knee pain localized to the tibial tuberosity is likely to have tibial apophysitis, or Osgood-Schlatter lesion.

C/O :waxing and waning of knee pain for a period of months. Pain worsens with squatting, walking up or down stairs.

This overuse apophysitis is exacerbated by jumping and hurdling, because repetitive hard landings place excessive stress on the insertion of the patellar tendon.

O.E :The tibial tuberosity is tender and swollen, and warm.

The knee pain is reproduced with resisted active extension or passive hyperflexion of the knee. No effusion is present.

Radiographs are usually negative; rarely, they show avulsion of the apophysis at the tibial tuberosity. *

PATELLAR TENDONITISJumper's knee (irritation and inflammation of the patellar

tendon)Most commonly occurs in teenage boys, particularly during

a growth spurt.

The patient reports vague anterior knee pain that has persisted for months and worsens after activities such as walking down stairs or running.

O.E: The patellar tendon is tender,The pain is reproduced by resisted knee extension. There is usually no effusion.

SLIPPED CAPITAL FEMORAL EPIPHYSIS* Poorly localized knee pain and no history of knee trauma.Pt is usually overweight Affected hip slightly flexed and externally rotated. The knee examination is normal.

Hip pain is elicited with passive internal rotation or extension of the affected hip.

Radiographs typically show displacement of the epiphysis of the femoral head

**

OSTEOCHONDRITIS DISSECANS* In the knee, the medial femoral condyle is most commonly

affected.C/O : vague, poorly localized knee pain, as well as morning

stiffness or recurrent effusion.- mechanical symptoms of locking or catching of the knee joint also may be reported

O.E: Quadriceps atrophy. Tenderness along the involved chondral surface.

A mild joint effusion may be present.Plain-film radiographs: osteochondral lesion or a loose body

in the knee joint. **Magnetic resonance imaging (MRI) is highly sensitive in

detecting these abnormalities

Common Knee problems in

Adults

ANTERIOR KNEE PAINPatello-Femoral pain syndrome (chondromalacia

patellae)vague history of mild to moderate anterior knee pain that usually occurs after prolonged periods of sitting.*

O.E: Effusion may be present, Patellar crepitus on ROM. Pain may be reproduced by applying direct pressure

at the anterior aspect of the patella.

Patellar tenderness. **

MEDIAL KNEE PAIN Medial Plica Syndrome: Acute onset of medial knee pain after a marked Increase of usual activities.

O.E :Tender, mobile nodularity is present at the medial aspect of the knee

LATERAL KNEE PAIN iliotibial band tendonitis:Commonly occurs in runners and cyclists. Pain at the lateral aspect of the knee joint. The pain is aggravated by activity, particularly running downhill and climbing stairsPredisposing factors: Tightness of the iliotibial band, excessive foot pronation, genu varum, and tibial TorsionO.E: Tenderness is present at the lateral epicondyle of the

femur, approximately 3 cm proximal to the joint line. Soft tissue swelling and crepitus

TRAUMAANTERIOR CRUCIATE LIGAMENT SPRAIN Due to noncontact deceleration forces, as when a runnerplants one foot and sharply turns in the opposite direction.

Resultant valgus stress on the knee leads to anteriordisplacement of the tibia and sprain or rupture of theLigament.

Patient usually reports hearing or feeling a “pop” at the time of the injury.

Swelling of the knee within two hours after the injury indicates rupture of the ligament and consequent hemarthrosis

O.E.Moderate to severe joint effusion that limits rangeof motion.The anterior drawer test may be positive.*The Lachman test should be positive.

Radiographs: to detect possible tibial spine avulsion fracture.

MRI of the knee is indicated as part of a presurgical evaluation.

MEDIAL COLLATERAL LIGAMENT SPRAIN

Result of acute trauma.Pt. c/o misstep or collision that places valgus stress on the knee,

followed by immediate onset of pain and swelling at the medial aspect of the knee

O.E :Point tenderness at the medial joint line.Valgus stress testing of the knee flexed to 30 degrees reproduces the pain.*

LATERAL COLLATERAL LIGAMENT SPRAIN

Much less common than injury of the medial collateral ligament.Results from varus stress to the knee, as occurs when person plants one foot and then turns toward the ipsilateral knee.Pt. C/o acute onset of lateral knee pain that requires prompt

cessation of activity.O.E. : Point tenderness is present at the lateral joint line.Instability or pain occurs with varus stress testing of the knee flexed to 30 degrees

MENISCAL TEARResults due to sudden twisting injury of the knee.*Also may occur in association with a prolongeddegenerative process.The patient usually reports recurrent knee pain and episodes of catching or locking of the knee joint, especially with squatting or twisting of the knee.

O.E : A mild effusion is usually present. Tenderness at the medial or lateral joint line.

The McMurray test may be positive.

MRI is the radiologic test of choice.

INFECTIONPatients of any age. *Abrupt onset of pain and swelling of the knee with noantecedent trauma.O.E : Knee is warm, swollen, and exquisitely tender.

Even slight motion of the knee joint causes intense pain.

Arthrocentesis reveals turbid synovial fluid: WBC > 50,000 per mm3 , PMNC > 75 % Elevated protein content (greater than 3 g per dL)low glucose concentration.

Gram may demonstrate the causative organism. Common are : Staphylococcus aureus, Streptococcus species, Haemophilus

influenzae, and Neisseria gonorrhoeae.Hematologic studies: elevated WBC, elevated PMNC, elevated ESR, CRP

Common Knee problems in Older Adults

OSTEOARTHRITISCommon problem after 60 years of age. Knee pain that is aggravated by weight-bearing activities and relieved by rest.No systemic symptoms but usually awakens with morning stiffness.May report episodes of acute synovitis.

O.E : Decreased range of motion, crepitus, a mild joint effusion, and palpable osteophytic changes at the knee joint.

Radiograph: joint-space narrowing, subchondral bony sclerosis, cystic changes, and hypertrophic osteophyte formation.

CRYSTAL-INDUCED INFLAMMATORY ARTHROPATHY

Acute inflammation, pain, and swelling in the absence of trauma.

In gout sodium urate crystals precipitate in the knee joint and cause an intense inflammatory response.

In pseudogout, calcium pyrophosphate crystals are the causative agents.

O.E: The knee joint is erythematous, warm, tender, and swollen. Even minimal range of motion is exquisitely painful.

Arthrocentesis: clear or slightly cloudy synovial fluid.

Analysis of the fluid yields a WBC count of 2,000 to 75,000 per mm3 a high protein content (greater than 32 g per dL,)and a glucose concentration that is approximately 75 percent of the

serum glucose concentration.

Polarized-light microscopy of the synovial fluid displays:negatively birefringent rods in the patient with gout

and positively birefringent rhomboids in the patient with pseudogout.

POPLITEAL CYSTThe popliteal cyst (Baker's cyst) is the most common synovialcyst of the knee.It originates from the posteromedial aspect of the knee joint at the level of the gastrocnemio-semimembranous bursa.Pt. c/o insidious onset of mild to moderate pain in the

popliteal area of the knee.O.E palpable fullness at the medial aspect of the popliteal area,

or near the origin of the medial head of the gastrocnemius muscle.

Definitive diagnosis of a popliteal cyst may be made with arthrography, ultrasonography, CT scanning.

Take home Messages

Teenage girls and young women are more likely to have patellar tracking problems such as patellar subluxation and patellofemoral pain syndrome.

Teenage boys and young men are more likely to have knee extensor mechanism problems such as tibial apophysitis (Osgood-Schlatter lesion) and patellar tendonitis.

Referred pain resulting from hip joint pathology, such as slipped capital femoral epiphysis, also may cause knee pain.

Active patients are more likely to have acute ligamentous sprains.

Trauma may result in acute ligamentous rupture or fracture, leading to acute knee joint swelling and hemarthrosis.

Septic arthritis may develop in patients of any age, but crystal-induced inflammatory arthropathy is more likely in adults.

Osteoarthritis of the knee joint is common in older adults.

Accurate diagnosis requires:1. knowledge of knee anatomy, 2. common pain patterns in knee injuries, and3. features of frequently encountered causes of knee pain,

as well as specific physical examination skills.

The history should include 1. characteristics of the patient's pain, 2. mechanical symptoms (locking, popping, giving way), 3. joint effusion (timing, amount, recurrence), and4. mechanism of injury.

The physical examination should include:

1. careful inspection of the knee, 2. palpation for point tenderness, assessment of

joint effusion, range-of-motion testing, 3. evaluation of ligaments for injury or laxity,

and assessment of the menisci.