What is the assessment and treatment for a 16-year-old male with bilateral knee pain, worse on the left, after a hockey injury?

Assessment and Treatment of Bilateral Knee Pain in a 16-Year-Old Hockey Player

Begin with bilateral knee radiographs (anteroposterior and lateral views) as the initial imaging study, since this patient meets Ottawa Knee Rule criteria with likely focal tenderness and/or effusion from acute trauma. 1

Initial Clinical Assessment

Perform a focused history and physical examination looking specifically for:

• Focal bony tenderness over the patella, fibular head, or joint lines 1
• Joint effusion (visible swelling or ballottement) 1
• Ability to bear weight and take four steps 1
• Range of motion, particularly ability to flex to 90 degrees 1
• Mechanism of injury (twisting, direct blow, hyperextension) to guide differential diagnosis 2
• Mechanical symptoms such as locking or catching that suggest meniscal injury 2

Key Clinical Decision Rules

The Ottawa Knee Rule applies to this 16-year-old patient and indicates radiographs are warranted if ANY of the following are present: 1

• Age ≥55 years (not applicable here)
• Isolated patellar tenderness
• Fibular head tenderness
• Inability to flex knee to 90°
• Inability to bear weight immediately after injury or take 4 steps in the emergency department

The bilateral nature of this injury is unusual and warrants careful evaluation of both knees, as bilateral injuries from a single mechanism may suggest patellar dislocation, dashboard injury, or other significant trauma patterns. 1

Initial Imaging

Obtain bilateral knee radiographs (minimum two views: AP and lateral) for both knees given the acute trauma setting and likely presence of focal tenderness or effusion. 1

The lateral view should be obtained with the knee at 25-30 degrees of flexion to:

• Visualize the patella in profile 1
• Evaluate for joint effusion 1
• Detect lipohemarthrosis (indicating intra-articular fracture) if cross-table technique is used 1

Additional views to consider based on clinical findings: 1

• Patellofemoral (sunrise) view if patellar fracture or subluxation/dislocation is suspected
• Internal and external oblique views for better fracture characterization

If Radiographs Are Negative

MRI without IV contrast is the next appropriate imaging study if radiographs show no fracture but clinical suspicion remains high for internal derangement (meniscal tear, ligament injury) or occult fracture. 1

MRI is superior for detecting: 1

• Bone marrow contusions and occult fractures with high sensitivity
• Meniscal tears (sensitivity/specificity ~88-90%) 1
• Ligamentous injuries including ACL, PCL, collateral ligaments (sensitivity/specificity 90-97% for ACL) 1
• Physeal injuries in skeletally immature adolescents

CT without IV contrast may be considered as an alternative if MRI is unavailable or contraindicated, particularly for evaluating occult fractures, though it is inferior to MRI for soft tissue evaluation. 1

Treatment Approach

If Fracture Is Identified:

• Immobilization and orthopedic referral based on fracture type and displacement 1
• Non-weight bearing or protected weight bearing as indicated

If No Fracture but Soft Tissue Injury Suspected:

Conservative management is first-line for most knee injuries in adolescents: 2

• Activity modification and relative rest from hockey 2

• Ice, compression, elevation for acute inflammation 2

• Physical therapy focusing on:

  • Quadriceps and hip strengthening (particularly gluteus medius) 2, 3
  • Range of motion exercises once acute pain subsides 2
  • Sport-specific rehabilitation before return to play 2

• NSAIDs for pain control if not contraindicated 2

• Weight management if applicable 2

Specific Injury Patterns:

For suspected meniscal tears: 2

• Conservative management with exercise therapy for 4-6 weeks is appropriate for most tears
• Surgery only indicated for severe traumatic tears (e.g., bucket-handle) with displaced tissue
• Mechanical symptoms alone do not mandate surgery

For patellofemoral pain: 2

• Hip and knee strengthening exercises
• Consider patellar taping or foot orthoses
• Surgery is not indicated

For suspected ligamentous injury:

• Degree of instability determines treatment
• Most partial tears respond to conservative management with bracing and physical therapy
• Complete ACL tears in active adolescent athletes typically require surgical reconstruction

Red Flags Requiring Urgent Referral

Immediate orthopedic consultation if: 4

• Severe pain with inability to bear weight
• Gross deformity or dislocation 1
• Signs of vascular compromise (absent pulses, pallor)
• Suspected open fracture or penetrating injury 1
• Large tense effusion suggesting hemarthrosis
• Signs of infection (fever, erythema, warmth, severe pain with any motion) 4

Common Pitfalls

• Do not skip radiographs in acute trauma patients who meet Ottawa criteria, even if the injury seems minor 1
• Do not order MRI as initial imaging in acute trauma—radiographs first 1
• Bilateral injuries warrant careful evaluation of both knees, as the "less symptomatic" side may still have significant pathology 1
• Physician judgment supersedes clinical decision rules if clinical suspicion is high 1
• Consider growth plate injuries in this age group, which may not be apparent on initial radiographs and may require MRI 1