What is the preferred initial management for a minimally displaced subcortical microtrabecular fracture of the lateral tibial plateau in a stable knee?

Management of Minimally Displaced Subcortical Microtrabecular Fracture of the Lateral Tibial Plateau

For a minimally displaced subcortical microtrabecular fracture of the lateral tibial plateau in a stable knee, nonoperative management with protected mobilization is the preferred initial treatment, as operative intervention provides no clinically meaningful improvement in patient-reported outcomes and carries significantly higher complication and reoperation rates. 1

Initial Diagnostic Workup

Confirm Diagnosis with CT Imaging

• Obtain CT of the knee immediately after radiographs show a subtle tibial plateau abnormality, as CT demonstrates 100% sensitivity for detecting tibial plateau fractures compared to only 83% for radiographs alone and provides superior characterization of fracture severity 2
• CT is critical for measuring articular surface depression—the key determinant of associated soft tissue injuries and treatment planning 2
• Radiographs miss 17% of tibial plateau fractures that CT detects, so a "subtle feature" on plain films mandates CT rather than clinical observation alone 2

Determine Need for MRI Based on CT Findings

• Order MRI after CT if articular depression exceeds 11 mm, as this threshold predicts higher risk of lateral meniscus tear and ACL avulsion fracture 2, 3
• MRI is also indicated if you have clinical suspicion of meniscal or ligamentous injury (mechanical symptoms such as locking, catching, or giving-way), or if surgical planning is being considered 2, 3
• MRI provides superb contrast resolution and multiplanar capability for evaluating bone marrow contusions, occult fracture extension, meniscal injuries, and ligamentous injuries 2

Treatment Algorithm for Minimally Displaced Fractures (≤4 mm)

Nonoperative Management (Preferred Initial Approach)

• Initiate protected mobilization for fractures with displacement ≤4 mm and a stable knee, as this approach yields equivalent patient-reported outcomes to surgery at midterm follow-up while avoiding surgical complications 1, 4
• Protected mobilization means weight-bearing as tolerated with crutches or walker, progressive range-of-motion exercises, and serial radiographic monitoring 4
• Complications occur in 0% of nonoperatively managed patients, and only 6% require delayed surgery by midterm follow-up 1

When to Consider Operative Treatment

• Reserve operative intervention for fractures with articular depression >8-10 mm, as this degree of displacement compromises joint congruity and stability 5, 4
• Surgery is also indicated if the knee is unstable (ligamentous injury confirmed on MRI) or if there is significant displacement of the cortical envelope that cannot be maintained with closed treatment 6
• For fractures meeting operative criteria, arthroscopically assisted percutaneous screw fixation provides excellent articular visualization with less soft-tissue morbidity than traditional open reduction and internal fixation 6

Evidence Supporting Nonoperative Management for Minimal Displacement

Patient-Reported Outcomes

• A 2024 multicenter study of 495 patients with tibial plateau fractures displaced ≤4 mm found that operative treatment was not associated with improved KOOS scores compared to nonoperative treatment after controlling for age, gender, BMI, smoking, diabetes, fracture gap, stepoff, AO/OTA classification, and number of involved segments 1
• In fact, operative treatment resulted in slightly poorer scores for pain (-4.7 points), sports (-7.6 points), and quality of life (-7.8 points), though these differences did not reach the minimum clinically important difference thresholds 1

Complication and Reoperation Rates

• Operative treatment carries a 4% complication rate versus 0% for nonoperative treatment in minimally displaced fractures 1
• Reoperation occurs in 39% of operatively treated patients versus only 6% of nonoperatively treated patients, with most surgical reoperations (36%) being elective hardware removal 1
• Open reduction and internal fixation has been associated with wound complications and infection rates as high as 12% 6

Critical Pitfalls to Avoid

Do Not Skip CT After Subtle Radiographic Findings

• A "subtle feature" on radiographs warrants CT rather than clinical observation, as radiographs miss 17% of tibial plateau fractures 2
• CT provides the articular depression measurement that drives all subsequent management decisions 2

Do Not Operate on Minimally Displaced Fractures Based on Outdated Criteria

• The traditional 2-mm displacement threshold for surgery was based on older studies using plain radiographs rather than CT 1
• Modern evidence with CT-based measurements demonstrates that fractures with up to 4 mm of displacement do equally well with nonoperative treatment 1

Do Not Delay MRI When Indicated

• If CT shows articular depression >11 mm, obtain MRI promptly to evaluate for meniscal and ligamentous injuries that would alter management 2, 3
• In patients under 40 years with acute knee injury and effusion >10 mm on lateral radiograph, early MRI decreases delayed diagnosis and improves outcomes 3

Do Not Order Unnecessary Advanced Imaging

• MR arthrography, MRA, bone scan with SPECT/CT, and ultrasound are not indicated for tibial plateau fracture evaluation 2
• These modalities have lower sensitivity, specificity, and accuracy than standard MRI for associated injuries 2

Patient Counseling Points

For Patients Choosing Nonoperative Treatment

• Complications are rare (0% in published series) 1
• Only 6% of patients require surgery by midterm follow-up 1
• Functional outcomes at midterm follow-up are equivalent to those achieved with surgery 1

For Patients Choosing Operative Treatment Despite Minimal Displacement

• Complications may occur in up to 4% of patients 1
• 39% of patients undergo a secondary intervention, most commonly elective implant removal 1
• No improvement in pain, function, or quality of life should be expected compared to nonoperative treatment 1