TOC  |  Rheumatology  

Approach to Knee Pain       REF: Painful Knee Test 2008
Strategy I.  
Separate all knee pain patients into one of three categories:

1. Routine office visit knee pain
2. The hot swollen atraumatic knee - need knee tap
   Septic arthritis
   Gout, pseudogout
   Autoimmune-inflammatory
3. Acute knee injury:  the blow out  --> See  the Examination &  the Referral Decisions for acutely injured knee below!

Strategy II.  
Analyze the location of the most painful part of knee in all routine office visit knee pain complaints
Anterior - Medial - Lateral - Posterior Knee Areas

Anteriorly Patellofemoral syndrome - the most frequent cause of knee pain Overuse syndrome, Runner's knee, peripatellar pain syndrome, chondromalacia patella, recurrent subluxation, mal-alignment syndrome, patellofemoral arthralgia, adolescent knee syndrome, peripatellar causalgia. Pre-patellar bursitis Patellar tendinitis Quadriceps tendinitis Pes Anserinus bursitis/tendinitis Plica syndrome Chondromalacia patella Osgood-Schlatter disease

Medially Meniscal tear or cyst Symptoms of meniscal pathology:  pain, swelling, locking with flexion, giving way Signs: medial joint line tenderness, effusion/synovitis, locked knee, atrophy, loss of full extension or flexion Osteoarthritis History: older age, activity trauma, surgery, effusions, pain P/E:  joint line tenderness, varus, crepitation, effusion, Pain at extreme motion X-ray:  narrowing, osteophytes, sclerosis, cysts Rx:  bicycling, PT Rx, NSAID, chondroitin & glucosamine, activity modification, steroid injection, surgery, ? hyaluronate injection? Osteochondritis dissecans (rare) Cause unknown, may be avascular necrosis of bone or femoral condyle Teenage boys ? girls 10:1 Pain, swelling +/- locking, effusion, atrophy, tenderness, 1 year course Knee X-ray of Tunnel View Refer to Ortho for persistent pain, effusion, or locking Rx: activity modification _/- arthroscopy Osteonecrosis of the femoral condyle (rare) Older age group > 60 yo  with sudden severe pain while walking ("spontaneous") Pain unrelenting, tumor like , unresponsive to usual Osteoarthritis Rx Initial X-ray negative, Tunnel View x-ray positive, later MRI shows avascular necrosis (AVN) Crutches, steroids, bike exercise, may need TKR (Total Knee Replacement)

Laterally Meniscal tear, cyst, discoid Meniscal Cyst (Lateral > Medial) is the mucinous degeneration in a meniscus that produces a mass over or near lateral joint line.  Never a tumor. Ignore if possible.  Aspirate if requested x1.  Definitive Rx includes a menisectomy, so treat by benign neglect if possible. Symptoms of meniscal pathology:  pain, swelling, locking with flexion, giving way Signs: join line tenderness, effusion/synovitis, locked knee, atrophy, loss of full extension or flexion Osteoarthritis Ilio-Tibio-"Band" Fascia Friction syndrome Usually sports related, high arches, the only cause of pain & tenderness above lateral joint line! Rx:  stretch ITB, warm up, ice, NSAID, steroid injections last resort. Biceps tendinitis Activity related, tender tendon at posterolateral side of knee above fibular head.

Posteriorly Knee Effusion of any cause Large amount of synovial fluid commonly produces tightness, fullness, or discomfort in back of knee. Rx the cause of effusion. Baker's cyst Usually due to the herniation of fibrosynovial knee tissue into the popliteal fossa due to intra-articular disease.  Always benign, best ignored. Aspirate x1 only if needed to prove diagnosis. Sciatica May cause pain behind knee from radiculopathy or hamstring spasm.  A pseudo-flexion contracture may be present.

Strategy III. ** Consider Timely Orthopedic Referral for the following patients:

• Recurrent effusion (in otherwise "healthy" knee)
  
• Giving way (with strong quadriceps muscle)
  - torn meniscus
  - loose body
  - patella subluxation
  - ligamentous instability
• Locking of the knee (not pseudo-locking)
  - torn meniscus
  - loose body
  - osteoarthritis
  - pseudolocking
• Definite loud pop at time of injury
  - Anterior Cruciate Ligament ACL Tear
  - Meniscus Tear
  - Dislocated patella
  - Torn MCL

Patello-femoral Pain Syndrome      

Symptoms of Patello-femoral Pain Syndrome

• Anterior knee pain
• Popping & clicking
• Instability - Giving Way
• Pseudo-locking
• Pain after sitting (movie sign)
• Pain ascending stairs
• Effusion & "swelling" are not usual
• The patellar pain are aggravated by flexed knee activities as sitting, climbing, squatting

Physical Findings in Patello-femoral Pain Syndrome

• Muscle contractures
• Quadriceps atrophy
• Q-Angle increased
• Foot alignment (pronation)
• Apprehension Sign (in dislocators)
• Effusion, heat are not typical

Conservative Rx of Patello-femoral Pain Syndrome  

• Stretching
• Strengthening
• Orthotics
• Soft goods
• Activity modification
• NSAID  as analgesics

Surgical Rx of Patello-femoral Pain Syndrome

• Soft Tissue:
  • Lateral release
  • Proximal realignment
  • Distal realignment
• Bone Tissue:
  • Distal realignment
  • Tibial tubercle osteotomy
  • Chondroplasty
  • Patellectomy

Prepatellar Bursitis ("Housemaid's Knee") :  Sterile bursitis

• vs septic bursitis (abscess & cellulitis) which looks awful with moderate pain.
• Rx of septic bursitis: aspirate or I/D, culture & sensitivity, antibiotics Rx

Patellar Tendinitis ("Jumper's Knee")

• Pain & tenderness in tendon below patella
• Rx: warm up, stretch, NSAID, ice, activity modification, brace.

Quadriceps Tendinitis

• Pain & tenderness above patella, ma lead to rupture
• Rx:  stretch, strengthen, activity modification, etc.

Pes Anserinus Bursitis/ Tendinitis

• Pain, tenderness, & swelling below medial joint line anteriorly
• Differential Dx:  stress fracture of tibia

Plica Syndrome

• Overly diagnosed, normal fibrosynovial fold in knee
• Rarely a cause of knee pain except after a direct blow

Chondromalacia patella

• It is age related & usually asymptomatic
• It should be rejected as a clinical diagnosis
• The identical clinical syndrome can occur when the articular cartilage has a normal appearance  (Insall 1982)

Osgood-Schlatter Disease:

• Traction apophysitis, esp. in teenage boys.
• Tender & swollen over tibial tubercle
• Rx: activity modification (rest, no jumping), stretch, strengthen, ice

General Treatment of Painful Knees:        

Bicycling!

• Strengthens muscles
• Aerobic fitness decreased chronic pain
• Weight control
• Mechanical smoothing
• Stimulates some healing in cartilage

Others:

• Stretch & strengthen
• NSAID
• Activity modification
• Steroid injections
• Softwear

The Examination of The Acutely Injured Knee         
*  Must get knee x-ray for all acute injured knee to rule out fracture or loose bodies.

The Critical Questions (History)

1. 1st time or recurrent problem, has it happened before?
2. Loud "POP" at time of injury (Anterior Cruciate Ligament Tear?)
3. Timing of swelling (SLOW - effusion; FAST - hemarthrosis)
4. Can pt continue the activity/sport or not

Six Steps to Evaluating The Acutely Injured Knee:

1. Support the painful knee with a support ("a can") to keep the flexion about 20^o
2. Check for knee effusion vs hemarthrosis
3. Check for Range of Motion assisted:  Is the knee locked, cannot extend of flex over 90^o
4. Examine the Patella for stability & retinacular tenderness
   - Apprehension  Sign (Fairbank's Test) - move Patella laterally
   - Medial patellar Retinacular tenderness
   - Hemarthrosis
5. Examine the Ligaments (R/O Tear) by palpation & stress maneuver
   - MCL (Medial Collateral Ligament): palpate & stress it
   - ACL (Anterior Cruciate Ligament):  Lachman's test & pivot shift
   - LCL (Lateral Collateral Ligament):  palpate & stress it
   - PCL (Posterior Cruciate Ligament): Sag sign
6. Examine the Extensor mechanism: integrity versus disruption
   - active extension possible?
   - palpate patellar tendon for defect (rupture)
   - palpate quadriceps tendon for defect (rupture)
   - compare location of right & left patellae

Initial Treatment of Sprained Knee (Except displaced fractures)

• Aspiration rarely needed
• Minor:  RICE (rest, ice, compression, elevation); crutches, partial weight bearing
• Major:  large compressive bandate "Jones", splint slightly flexed, crutches, analgesics (NSAID)

Referral Decisions for The Acutely Injured Knee:    

Immediate Orthopedic Consultation for:

• All fractures
• Quadriceps Tendon Tear
• Patellar Tendon Tear
• Dislocated unreduced Patella
• Locked Knee

Early (within 1 week) Orthopedic Consultation for:

• Acute ACL/PCL (Anterior/Posterior Cruciate Ligament) Tears
• Grade 3 MCL/LCL  (Medial/Lateral Collateral Ligament) Tears
• Acute Patellar Dislocation

Elective Orthopedic Consultation for:

• Recurrent Patellar Dislocation
• Chronic ACL/PCL Tears

       05072003 Most of the written material from the Knee Workshop  by Dr. Barry J. Miller 2003