What is the recommended treatment for an adult or adolescent patient with a patellar fracture, considering their history of physical activity and potential pre-existing medical conditions such as osteoporosis?

Treatment of Patellar Fractures: Knee Brace Use and Management

For patellar fractures, treatment depends critically on fracture displacement and extensor mechanism integrity: undisplaced fractures with intact extensor mechanism can be treated conservatively with immobilization (cast or brace), while displaced fractures (>2-3 mm step-off or >1-4 mm displacement) or those disrupting the extensor mechanism require surgical fixation. 1

Initial Assessment and Treatment Decision Algorithm

Determine fracture displacement and extensor mechanism integrity immediately:

• Undisplaced fractures (<2-3 mm step-off, <1-4 mm displacement) with intact extensor mechanism → Conservative treatment with immobilization 1
• Displaced fractures (>2-3 mm step-off or >1-4 mm displacement) OR disrupted extensor mechanism → Surgical fixation required 1

Critical Imaging Consideration

• Obtain CT scan of the knee when available, as it frequently modifies both fracture classification and treatment choice compared to plain radiographs alone, revealing greater fracture complexity 1

Conservative Treatment Protocol (For Undisplaced Fractures)

Use a simple immobilization device (cast or knee brace) for 4 weeks, followed by early mobilization:

Brace Selection Evidence

• A neoprene nonhinged knee brace (allowing full range of motion) is superior to motion-restricting braces based on the highest quality evidence available 2
• Motion-restricting braces (limiting ROM to 0-30°) cause significantly more quadriceps atrophy at 4 weeks (75% vs 50% of patients, p=0.048), reduced knee ROM at 4 weeks (90° vs 115°, p<0.001) and 3 months (125° vs 133°, p=0.028), and worse functional outcomes at 6 months 2
• Motion restriction does NOT reduce redislocation rates (34.4% vs 37.5%, p=0.794) 2

Conservative Treatment Protocol

• Immobilize for 4 weeks maximum with neoprene nonhinged brace 2
• Initiate appropriate pain management with analgesics to facilitate early mobilization 3
• Begin early physical training and muscle strengthening immediately after the 4-week immobilization period 3
• Implement long-term balance training and multidimensional fall prevention programs 3

Surgical Treatment (For Displaced Fractures)

Surgical options include tension band wiring (most common), angular stable patella plating, percutaneous osteosynthesis, or cable pin systems:

Surgical Technique Selection

• Tension band fixation remains the most commonly employed technique, though hardware removal is frequently required after healing due to implant-related pain 1
• Angular stable patella plating shows promising results with only 3% implant-related complications, average flexion of 127°, and 77% return to pre-injury function, particularly beneficial for multi-part, comminuted, or osteoporotic fractures 4
• Anatomical reconstruction of the articular surface is mandatory to prevent posttraumatic osteoarthritis 1

Evidence Limitations

• Very low-quality evidence means uncertainty exists regarding superiority of percutaneous osteosynthesis versus open surgery, cable pin systems versus tension band technique, or biodegradable versus metallic implants 5

Postoperative Management

Implement comprehensive postoperative care focusing on early mobilization and complication prevention:

• Provide appropriate pain management considering patient comorbidities (avoid NSAIDs in CKD/cardiovascular disease) 3, 6
• Begin range-of-motion exercises within the first postoperative days 6
• Avoid prolonged bed rest as it accelerates bone loss, muscle weakness, and increases DVT/pressure ulcer risk 6
• Monitor for complications including nonunion, infection, posttraumatic arthritis, arthrofibrosis, symptomatic hardware, and extensor mechanism insufficiency 7

Secondary Fracture Prevention (Critical for Patients ≥50 Years)

Every patient aged 50 years and over requires systematic osteoporosis evaluation:

Immediate Assessment

• Order DEXA scan, vitamin D level, calcium level, and parathyroid hormone level 8
• Perform FRAX analysis (for patients ≥40 years) and BMD with vertebral fracture assessment 3
• Assess clinical fracture risk factors including glucocorticoid use, smoking, alcohol, prior fractures, fall history 3

Pharmacological Prevention

• Calcium 1000-1200 mg/day and vitamin D 800 IU/day for all patients (reduces non-vertebral fractures by 15-20% and falls by 20%) 6
• Oral bisphosphonates (alendronate or risedronate) for high/very high fracture risk patients with GFR ≥30 mL/min 3, 6
• Denosumab 60 mg subcutaneously every 6 months for patients with GFR <30 mL/min or oral intolerance 6

Non-Pharmacological Prevention

• Smoking cessation and alcohol limitation 3, 6
• Weight-bearing exercise programs to improve BMD and muscle strength 6
• Multidimensional fall prevention programs (reduces fall frequency by ~20%) 6

Common Pitfalls to Avoid

• Do not use motion-restricting braces for conservative treatment - they cause quadriceps atrophy and worse functional outcomes without reducing complications 2
• Do not rely solely on plain radiographs - CT imaging frequently changes treatment decisions 1
• Do not accept >2-3 mm articular step-off - anatomical reduction is essential to prevent posttraumatic arthritis 1
• Do not neglect osteoporosis screening in patients ≥50 years - systematic evaluation and treatment prevents subsequent fractures 3, 8