Knee Problems
Cure Conference
Mike Mazzone
Waukesha Family Medicine
Outline
Brief Review of evaluation of the
knee
Discuss Differential Diagnosis
Review Treatment Modalities
Brief Overview
1/3 of all musculo-skeletal problems
seen in Primary Care are about the
Knee
54% of all Atheletes will experience
some knee pain EVERY YEAR
Things to think about in History
Pain characteristics – PQRST
Mechanical Symptoms
– Locking
– Popping
– Giving Way
Effusion
– Rapid (< 2 hours) – hemarthrosis
– Slow (24-48 hours) – ligamentous strain, meniscal Injury
Mechanism of Injury
–
–
–
–
–
Direct blow?
Foot planted
Decelerating or landing from a jump
Twisting
Hyperextension
Medical History
– Previous Knee pain or Surgery
Physical Exam
Inspection
Palpation
ROM – Normal 0 degrees to 135 degrees
Neuro
Special Tests
–
–
–
–
–
Lachman or Drawer – for ACL problems
McMurray or Apley Grinder – Meniscal Injuries
Milking of Suprapetallar Pouch
PatelloFemoral Tracking
Q angle (>15 degrees predisposes to Patellar
Subluxation
– Patellar Aprehension Test – push patella laterally
– Varus and Valgus Stress – MCL and LCL
Ottawa Rules for Obtaining a
radiograph in Acute Knee Injuries
Ottawa Rules
age 55 or over
isolated tenderness of the patella
(no bone tenderness of the knee
other than the patella)
tenderness at the head of the
fibula
inability to flex to 90 degrees
inability to weight bear both
immediately and in the ER (4
steps - unable to transfer weight
twice onto each lower limb
regardless of limping).
Sensitivity – 97%
Specificity – 27%
Reduced Radiographs by 28%
Pittsburg Rules
Blunt trauma or a fall as
mechanism of injury plus either
of the following:
– Age younger than 12 years or
older than 50 years
– Inability to walk four weightbearing steps in the emergency
department
Sensitivity – 99%
Specificity – 60%
Reduced Radiographs by 57%
What Radiographs to Order
Most Patients 3 views
– AP
– Lateral
– Merchants
Teenagers with chronic knee pain
and recurrent effusion
– Add Tunnel View (PA with knee flexed
40-50 degrees)
Loooks for osteochondritis dissecans on
Femoral Condyles)
AP View
Merchant’s view
Lateral View
Tunnel View
Lab
In presence of Warmth, exquisite tenderness and effusion
– Consider Septic Arthritis or Acute Inflammatory arthropathy
– Labs to order
CBC
ESR
Arthrocentesis for
–
–
–
–
–
Cell count and differential
Glucose
Protein
C&S
Polarized light microscopy
If unclear of diagnosis with an effusion – Arthrocentesis
If Rheumatoid Arthritis a possibility – ESR and RF
Differential Diagnosis by Age
Children and
Adolescents
– Patellar
Subluxation
– OsgoodSchlatter –
Tibial
Apophysitis
– Jumper’s Knee
– Patellar
Tendonitis
– Referred Pain –
Slipped Capital
Femoral
Epiphysis
– Osteochondritis
Dissecan
Adults
– Patellofemoral
Pain Syndrome
– Medial Plica
Syndrome
– Pes Anserine
Bursitis
– Traumatic Injury
Ligamentous
sprains
Meniscal
Injuries
– Inflammatory
Arthropathy
– Septic Arthritis
– Patellar Bursitis
– Iliotibal Band
Syndrome
Older Adults
– Osteoarthritis
– Crystal
Induced
arthropathy
– Baker’s Cyst
(Popliteal
Cyst)
Differential By Location
Anterior
– Patellar
Subluxation
– OsgoodSchlatter
– Jumper’s
Knee
– Patellofemor
al Pain
Syndrome
– Prepatellar
bursisits
Medial
– MCL Sprain
– Medial
Meniscal
Tear
– Pes
Anserine
Bursitis
– Medial Plica
Syndrome
Lateral
– LCL
Sprain
– Lateral
Meniscal
Tear
– Iliotibial
Band
Tendoniti
s
Posterior
– Baker’s
Cyst
– Posterior
Cruciate
Ligament
Injury
Patellar Subluxation
More common in Girls withLarge Q
angle (> 15 degrees)
History – Patella pops or gets stuck
PE – Patellar Aprehension Test
Treatment –
– Physical Therapy – cycling
– Patellar Bracing
– For Severe – Surgery
Osgood-Schlatter
(Tibial Apophysitis)
More common Teenage boys
History
– Knee pain waxing and waning for months
– Worsens with squatting or stairs
PE – tender on tibial tuberosity
Treatment
– Icing after activity
– Decreasing activity – may need to stop activity
for 2-3 months
– NSAID’s
– If severe – knee immobilizer for 2-6 weeks
Patellar Tendonitis
History
– Teenage boys
– Pain is anterior and has persisted for months
PE – tender over patellar tendon, pain
with knee extension
Treatment
– ICE
– NSAID’s
– Decreased Activity
Slipped Capital Femoral Epiphysis
(SCFE – pronouced Skiffy)
Overweight 10-16 yo Boys or 12-14 yo Girls
History
– Vague Knee pain with no trauma
Exam – pain on internal rotation of hip
Diagnosis – Xray AP/Lat view of Pelvis and b/l
hips
Treatment –
– Immediate Cessation of weightbearing
– Surgical stabilization
Take Home Point – ALWAYS EXAMINE HIP IN
KIDS WITH KNEE PAIN
Osteochondritis Dissecans
History
– Vague knee pain,
– morning stiffness and recurrent effusion
– possibly locking or catching
Exam
– possible quad atrophy
– effusion
– chondral tenderness
Radiographs to include Tunnel view
MRI test of choice if unclear diagnosis
Treatment
–
–
–
–
Rest
Bracing
Low Impact PT
Surgery if symptoms persist >2-3 months despite therapy
Patellofemoral Pain Syndrome
History
– Anterior knee pain worse after sitting (theatre sign)
PE
– patellar crepitus
– pain on contracting quad while putting pressure on Patella
– Widened Q angle
Treatment
– Relative rest
– Ice 20 minutes after activity
– Quadracep strengthening (consider hip, hamstring, calf and IT
band stretching)
– Evaluation of Footwear
– Consider NSAID’s
– Consider Knee braces
– Consider Knee taping – McConnell Taping
Medial Plica Syndrome
Plica – A redundancy of the joint synovium
Hx – Acute onset medial knee pain
PE – tender mobile nodularity
Treatment
–
–
–
–
NSAID’s
ICE
PT including phonophoresis and iontophoresis
Quad Strengthening Exercises
Pes Anserine Bursitis
Pes Anserine – insertion of Sartorius,
gracilis and semitendinosus muscles
Hx – pain on medial side of knee
worsened with flexion and extension
PE – tenderness posterior and distal to
medial joint line valgus stress may
reproduce pain
Treatment
– NSAID’s
– ICE
Iliotibial Band Tendonitis
Friction between IT band and Lateral
Femoral Condyle
Hx – Lateral Knee pain aggrevated by
activity
PE – Tenderness over lateral epicondyle of
femur while flexing and extending knee
(Noble test)
Treatment
– IT band stretching exercises
– NSAID’s
– ICE
Anterior Cruciate Ligament
Plant and turn injury
HX- often hears a pop and notes swelling in Knee
PE – Joint Effusion + Anterior Drawer or Lachman if torn
(most sensitive directly after injury or about 2 weeks later)
Radiographs looking for tibial spine avulsion
MRI prior to surgery if torn
Treatment
– Initial Treatment
RICE
Knee Immobilization
Crutches
NSAID’s
– Definitive treatment
Based on Age, Activitity level and degree of injury
Surgery vs prolonged immobilization
Medial Collateral Ligament (MCL)
Due to valgus stress
Hx – valgus stress then immediate pain and
swelling medially
PE – valgus stress testing
– Grade 1 – clearly defined endpoint and < 5m laxity
– Grade 2 – 5-10 mm of laxity with endpoint
– Grade 3 – no clear endpoint (complete tear)
Treatment
– Grade 1 – RICE and crutches as needed
– Grade 2 – RICE, crutches and hinged bracing
– Grade 3 – RICE, hinged brace – gradual return to
weightbearing over 4 weeks
Lateral Collateral Ligament (LCL)
Similar to MCL but much less
common
HX – Varus stress then immediate
pain
PE – Varus stress test
Treatment
– Grade 1 and 2 – same as MCL
– Grade 3 – may require surgery
Meniscal Tear
Can be acute or chronic
Hx – Recurrent knee pain with episodes of
catching, locking or giving way
PE – Mild effusion and positive McMurray
test
MRI best imaging test if diagnosis unclear
Treatment
– If no locking or instability – RICE, NSAID’s for
2-3 weeks
– Otherwise referral for surgical debridement
Septic Knee
Predisposing factors – cancer, DM, Etoh, AIDS,
corticosteroid therapy
Hx – Abrupt onset of pain and swelling no trauma
PE – warm, swollen, very tender
Lab
– CBC – left shift
– ESR > 50 mm/hr
– Arthrocentesis
Turbid synovial Fluid – WBC > 50 000 Neutrophils >75 percent
Protein > 3 g/dL
Glucose - 50 percent or less or serum glucose level
Treatment
– common pathogens Staphyloccus aureus, Streptococcus,
Haemophilus influenzae, Neisseria gonorrhoeae
– IV antibiotics
– Ortho referral for possible debridement
Osteoarthritis
Common > 60 years of age
Hx – Knee pain aggrevated by weight bearing relieved by
rest, morning stiffness
PE – decreased ROM, crepitus, osteophytic changes
Radiographs –
– Weightbearing – AP, PA tunnel
– Nonweightbearing –Merchant’s and lateral view
Treatment
– NSAID’s
– Corticosteroid injections
– Referral for Knee replacement if
Significant and disabling pain
Dysfunction significantly inhibiting quality of life
Should exhaust all clinical measures before considering surgery
Crystal-Induced Inflammatory
Arthropathy
Gout (sodium urate crystals) and Pseudogout
(calcium pyrophosphate crystals)
Hx- Acute onset, red hot and very tender knee
PE – erythematous, warm, tender swollen
Arthrocentesis
–
–
–
–
Clear or slightly cloudy – WBC 2K to 75K
Protein high >32 g/dL
Glucose 75% of serum
Polarized-light microscopy of synovial fluid shows
Gout - negatively birefringent rods
PseudoGout – positively birefringent rhomboids
Treatment
– NSAID’s
– Colchicine
Baker’s Cyst
Outpouching of synovial fluid
Hx
– insidious onset of mild to moderate pain in posterior
aspect of knee
– Ruptured cyst may present like DVT – red swollen and
tender calf
PE – palpable fullness present medial aspect of
popliteal area
Imaging – US, CT may help if diagnosis unclear
Treatment
– Aspiration may cause temporary relief but recurrence
rate is high
– Surgery if pain persistent and intolerable
Knee Braces
Types
– Prophylactic – prevent injury to uninjured knee (most common used by football
lineman)
Evidence mixed as to their effectiveness
Choose the longest brace that fits the athelete’s leg
Custom brace offer little extra benefit to off-the-shelf models
Price vary considerably
Need to wear brace with hinge near epicondyles
Strength training, flexibility and technique refinement much more important
DO not prevent rotation injures
– Functional – provide stability to unstable knee
No great studies
No studies showing custom fit better than pre-sized
More limitation than prophylactic braces ( do prevent rotation injuries as well)
Limiting extension to 10-20 degress may prevent hyperextension injuries
– Rehabilitative – allow protected and controlled motion during knee rehabilitation
– Patellofemoral Braces – improve patellar tracking
Studies mixed on effectiveness
Typically made of neoprene with butresses that support the patella – relatively
inexpensive
Prophylactic Brace
Functional Brace
PatelloFemoral Brace
Tips for Icing Knee
Recommend 10-20 minutes per session
(when it feels numb you are done)
Recommend 2-3 times per day
Ways to manage ice
– Plastic bag with some water
– Freeze water in styrofoam or dixie cup – then
peel cup away from top of ice for use
– Wet towel in Freezer
– Commercially available ice packs
References
Calmbach, W: Evaluation of Patients Presenting with Knee Pain:
Part I. History, Physical Examination, Radiographs, and Laboratory
Tests (AFP:68(5))
Calmbach, W: Evaluation of Patients Presenting with Knee Pain:
Part II. Differential Diagnosis (AFP:68(5))
Johnson, M: Acute Knee Effusions: A Systematic Approach to
Diagnosis (AFP:Vol 16(8))
Juhn, M: Patellofemoral Pain Syndrome: A Review and Guidelines
for Treatment (AFP:60(7))
Paluska, S: Knee Braces: Current Evidence and Clinical
Recommendations for Their Use (AFP: 61(2))
Solomon, D: Does the Patient have a torn Meniscus or Ligament of
the Knee? Value of the Physical Examination (JAMA:(286(13)) –
needs MCW proxy
Tandeter, H: Acute Knee Injuries: Use of Decision Rules for
Selective Radiograph Ordering (AFP: Vol 60(9))
Zuber, T: Knee Joint Aspiration and Injection (AFP:66(8))