What should be done for a 21-year-old patient with a history of left tibia and fibula fracture, treated with rod placement 6 years ago, now experiencing left ankle and knee pain after several months of working out at the gym?

Management of Post-Intramedullary Rod Pain in a Young Adult

This patient requires immediate plain radiographs of the left tibia/fibula (AP and lateral views) and left knee to evaluate for hardware complications, followed by MRI without contrast if radiographs are unrevealing, as new-onset pain 6 years post-fixation suggests either hardware failure, stress fracture adjacent to the rod, or soft tissue pathology rather than simple overuse injury. 1

Immediate Diagnostic Approach

First-Line Imaging

• Obtain plain radiographs immediately of the entire left tibia/fibula (including hardware) and left knee with AP, lateral, and oblique views 1
• Look specifically for:
  • Hardware loosening, breakage, or migration 1
  • Stress fractures at the proximal or distal ends of the intramedullary rod (common sites of stress concentration) 2
  • Delayed union or nonunion at the original fracture site 3, 4
  • New fracture lines 1
  • Joint effusion in the knee or ankle 1

If Radiographs Are Normal or Show Only Effusion

• Proceed directly to MRI without contrast of the affected regions (both knee and ankle/tibia as clinically indicated) 1
• MRI is the gold standard for detecting:
  • Bone marrow edema patterns indicating stress injury or insufficiency fracture 1, 2
  • Soft tissue pathology (tendinopathy, ligament injury, muscle strain) 1, 5
  • Early hardware-related complications not visible on radiographs 1
  • Bone marrow lesions that correlate with pain 1

Critical Red Flags Requiring Urgent Evaluation

Do not dismiss this as simple gym-related overuse given the hardware history and bilateral joint involvement 6. Specifically assess for:

• Night pain or pain at rest: This is a red flag for serious pathology including infection, stress fracture, or hardware failure—not simple overuse 1, 6
• Inability to bear weight: Suggests fracture or significant structural compromise 1
• Systemic symptoms: Fever, warmth, erythema suggest late periprosthetic/hardware infection (can occur years after implantation) 1
• Progressive pain despite activity modification: Indicates structural problem rather than simple overuse 7, 8

Initial Management Pending Imaging Results

Activity Modification

• Immediately cease all gym activities involving loaded knee flexion (squats, lunges, leg press) and impact activities (running, jumping) 7, 8
• Allow weight-bearing as tolerated with assistive devices (crutches) if needed for comfort 1, 5
• Avoid activities requiring repetitive knee flexion beyond 45 degrees until diagnosis is established 7

Pain Control

• Initiate NSAIDs (ibuprofen 400-600mg TID or naproxen 500mg BID) for pain control and anti-inflammatory effect 1, 5
• Apply ice to affected areas 15-20 minutes every 2-3 hours 5
• Use compression wrapping for any visible swelling 5

Timeline for Reassessment

• If symptoms do not improve within 3-5 days of activity modification and NSAIDs, expedite imaging 5
• If symptoms worsen at any point, obtain imaging immediately 5

Differential Diagnosis Specific to Hardware History

Hardware-Related Complications (Most Concerning)

• Stress fracture at rod ends: The proximal and distal ends of intramedullary rods create stress concentration points where bone is most vulnerable to fracture with increased activity 2
• Hardware loosening or breakage: Can occur years after placement, especially with increased mechanical loading from gym activities 1
• Delayed union/nonunion: May become symptomatic with increased activity 3, 4

Soft Tissue Pathology

• Patellofemoral pain syndrome: Common in young adults with altered biomechanics post-fracture 1, 7, 8
• Patellar tendinopathy: Overuse from gym activities 1, 7
• Ankle ligament injury or tendinopathy: May result from altered gait mechanics post-hardware placement 1

Bone Stress Injury

• Insufficiency fracture: Can occur in bone adjacent to hardware, especially with sudden increase in activity 2
• Bone marrow edema without fracture: Precursor to stress fracture 1

Definitive Management Algorithm

If Radiographs Show Hardware Complications

• Immediate orthopedic surgery referral for evaluation of hardware removal versus revision 1
• Hardware removal is typically considered once fracture healing is complete (usually >1 year post-placement), and may be indicated if causing symptoms 1

If MRI Shows Stress Fracture or Bone Marrow Edema

• Protected weight-bearing with removable boot or brace for 6-8 weeks 5, 2
• Gradual return to activity only after pain-free weight-bearing is achieved 5
• Consider bone health evaluation (vitamin D, calcium, metabolic bone disease workup) 2

If Imaging Shows Soft Tissue Pathology Only

• Structured physical therapy program focusing on:
  • Quadriceps strengthening (especially vastus medialis) with emphasis on eccentric contractions 8
  • Hip strengthening (gluteus medius, hip external rotators) 1, 8
  • Proprioceptive training 5, 8
  • Gradual progressive loading 8
• Continue for minimum 3 months before considering other interventions 7, 8

If All Imaging Is Normal

• Proceed with conservative management as above, but maintain high suspicion for evolving stress injury 1
• Repeat MRI in 4-6 weeks if symptoms persist despite appropriate conservative management 1

Common Pitfalls to Avoid

• Do not assume this is simple overuse tendinopathy without imaging given the hardware history—stress fractures at rod ends are common and can be catastrophic if missed 2
• Do not delay imaging beyond 1-2 weeks if symptoms persist with activity modification 5
• Do not restart gym activities until cleared by imaging and clinical examination—premature return to loading can convert stress reaction to complete fracture 2
• Do not ignore night pain—this is never normal and demands urgent evaluation 1, 6

Follow-Up Strategy

• Reassess at 3-5 days after initial presentation to ensure symptom improvement with conservative measures 5
• Obtain MRI at 2-3 weeks if no improvement or any worsening of symptoms 5
• Refer to orthopedic surgery if imaging shows hardware complications, stress fracture, or if symptoms fail to improve after 3 months of appropriate conservative management 7, 8