Rosen & Barkin's 5-Minute Emergency Medicine Consult (411 page)

• Children and adolescents show more laxity on exam than adults
  
• Examine hip and obtain radiograph if any concern for hip pathology (especially slipped capital femoral epiphysis)
  
• Have a high suspicion for epiphyseal growth plate injuries
  

• If cause of knee effusion not clearly traumatic, synovial aspirate can be sent for cell count, Gram stain, culture, crystals
  
• Arthrocentesis is usually not indicated after trauma except to relieve symptoms from tense effusion
  

• Ottawa knee rules (adults): Plain films required for patients with any of 5 findings:
  
  • Age ≥55
    
  • Isolated tenderness of patella
    
  • Tenderness at head of fibula
    
  • Inability to flex 90°
    
  • Inability to bear weight both immediately and in ED (4 steps)
    
• Standard radiography:
  
  • Obtain on all suspected ACL injuries due to high risk of fractures
    
  • Important in children to evaluate for tibial spine and growth plate fractures
    
  • Views: AP, lateral, oblique, notch
    
  • Special attention to avulsion fractures of the medial/lateral tibial spine and lateral tibial plateau, which can be seen with ACL/PCL injuries and may be more likely to be treated operatively
    
  • Fat–fluid level for fracture.
    
• MRI is around 95% sensitive for ACL tears and other intra-articular disorders (menisci, PCL, osteonecrosis, osteochondral lesions, occult fractures) and even more specific, but it is rarely indicated emergently.
  
• Arteriograms to evaluate vascular integrity for suspected dislocations
  
• US useful to diagnose cysts and popliteal artery aneurysms
  

Ottawa knee rules do not apply to children.

• Neurovascular evaluation
  
• Exclusion of fractures and infection
  
• Evaluate for multidirectional instability
  
• Valgus/varus stress at 20° of flexion
  
• Extensor mechanism function
  
• Lachman test for ACL injury
  

• Growth plate injury
  
• Tibial plateau bony injury, other fracture
  
• Transient knee dislocation
  
• Transient patellar dislocation
  
• Hip injury causing referred pain
  
• Nontraumatic causes of knee effusion and pain including septic joint, gout, osteoarthritis, rheumatoid arthritis
  

TREATMENT

• ABC’s, ATLS
  
• Immobilize knee
  
• Document neurovascular function
  
• Apply ice, elevate, analgesia
  

• Reduce locked knee from meniscus injury within 1st 24 hr after injury:
  
  • With patient seated, hang extremity off edge of exam table at 90°: This with analgesia alone may reduce locked joint.
    
  • Assist with applying gentle traction and rotation of tibia
    
• Arthrocentesis may afford relief with large effusions and assist in reducing locked joint:
  
  • Follow with compressive dressing
    
• Treatment (if no fracture):
  
  • Rest, Ice, Compression, Elevation
    
  • Weight Bearing as Tolerated, crutches for comfort if needed
    
  • May provide knee immobilization for protection, but encourage motion out of brace as much as possible, especially if follow-up may be delayed
    

• Pain control: NSAIDs preferred over opioids
  
• Ibuprofen: 400–600 mg (peds: 5–10 mg/kg) PO QID.
  

FOLLOW-UP

• Isolated ACL, PCL, meniscus, or collateral ligament injury rarely requires emergent hospitalization
  
• Low threshold to admit possible knee dislocations for monitoring
  
• Fractures often need ORIF to limit post-traumatic arthritis
  

Most patients can be managed as outpatients with appropriate referral.

• Re-exam is recommended at 48 hr if ED exam is inconclusive or if history suggests more significant injury than initial exam demonstrates (i.e., severe symptoms, hearing “pop”).
  
• Orthopedic referral within 1–2 wk if significant ligamentous injury is present.
  
• Surgical repair of all lesions may be considered for patients wishing to return to sports or active lifestyles.
  

• Do a careful neurovascular exam, and always examine 1 joint above and below the pain for associated injury or referred pain
  
• Have a high index of suspicion for a reduced total knee dislocation if patient has multidirectional knee instability or injuries to multiple ligaments
  
• Do not miss: Knee dislocation, fractures, septic joint, referred pain from hip, neurovascular injury
  

• Chen L, Kim PD, Ahmad CS, et al. Medial collateral ligament injuries of the knee: Current treatment concepts.
  Curr Rev Musculoskelet Med
  . 2008;1(2):108–113.
  
• Meuffels DE, Poldervaart MD, Diercks RL, et al. Guideline on anterior cruciate ligament injury: A multidisciplinary review by the Dutch Orthopaedic Association.
  Acta Orthop.
  2012;83(4):379–869.
  
• Noyes FR.
  Noyes’ Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes
  . Philadelphia, PA: Saunders-Elsevier; 2010.
  
• Ryzewicz M, Peterson B, Siparsky PN, et al. The diagnosis of meniscus tears: The role of MRI and clinical examination.
  Clin Orthop Relat Res.
  2007;455:123–133.
  

CODES

• 836.0 Tear of medial cartilage or meniscus of knee, current
  
• 844.1 Sprain of medial collateral ligament of knee
  
• 844.2 Sprain of cruciate ligament of knee
  

BASICS

Labor denotes the sequence of physiologic occurrences that result in a fetus being transported from the uterus through the birth canal.

• Labor brings about changes in the cervix to allow passage of fetus through birth canal
  
• Synchronous, coordinated contractions of the uterus
  
• Contractions progress in magnitude, duration, and frequency to produce dilation of the cervix and ultimate delivery
  
• Labor is divided into 3 stages:
  
  • Stage 1 (cervical stage): From onset of uterine contractions to full dilation of cervix
    
  • Stage 1 is further divided into latent and active phases:
    
    • In the
      latent phase
      , uterine contraction with little change in cervical dilation or effacement; contractions are mild, short (<45 sec), and irregular
      
    • This is followed by the
      active phase
      , which begins around time of cervical dilation of 3–4 cm; contractions are strong, regular (every 2–3 min), and last longer (>45 sec)
      
  • Stage 2: From onset of complete cervical dilation to time of delivery of infant
    
  • Stage 3: From time of delivery of baby to time of placental delivery
    
• Total duration of labor varies with each woman
  
• Generally, lengths of 1st and 2nd stages of labor are significantly longer for nulliparous woman:
  
  • Nulliparous: Mean length for 1st stage of labor is 14.4 hr and for 2nd stage of labor is 1 hr
    
  • Parous: Mean length of 1st stage of labor is 7.7 hr and for 2nd stage of labor is 0.2 hr
    
• Length of 2nd stage of labor is greatly influenced by “3 Ps”:
  
  • P
    assenger (infant size and presentation)
    
  • P
    assageway (size of bony pelvis and soft tissues)
    
  • P
    owers (uterine contractions)
    
• Problems with any of these 3 Ps can cause abnormal progression of labor:
  
  • Fetal malposition, uterine dysfunction, cephalopelvic disproportion
    
• False labor (Braxton Hicks contractions):
  
  • Irregular, nonsynchronous contractions of uterus several weeks to days before onset of true labor, and do not cause cervical dilation
    

• Premature labor occurs in 8–10% of pregnancies.
  
• 30–40% of premature labor is caused by uterine, cervical, or urinary tract infections
  
• Premature rupture of membranes is defined as rupture of amniotic/chorionic membranes at least 2 hr before onset of labor in patient before 37 wk gestation:
  
  • This occurs in only 3% of pregnancies but accounts for 30–40% of all premature births
    

DIAGNOSIS