Anterolateral Approach to the Proximal Tibia (Lateral Tibial Plateau)

The anterolateral approach to the proximal tibia provides direct access to the lateral tibial plateau and is the workhorse approach for the majority of lateral column tibial plateau fractures (Schatzker I-III). It is performed in the supine position with a bump under the ipsilateral hip. The incision is typically a hockey-stick or straight lateral incision centered over Gerdy's tubercle. The key deep step is subperiosteal elevation of the anterior compartment musculature (tibialis anterior) off the lateral metaphysis. A submeniscal arthrotomy allows inspection of the articular surface. The common peroneal nerve is at risk posterolaterally at the fibular neck, and the anterior tibial vessels are at risk 5-7 cm distal to the joint line. This approach allows lateral buttress plating and elevation of depressed articular segments with bone grafting.

Primary Indications:

• Schatzker Type I - pure lateral split fracture
• Schatzker Type II - lateral split-depression (most common indication)
• Schatzker Type III - pure lateral depression
• Lateral buttress plating for valgus instability
• Elevation of depressed articular segments with bone grafting
• Revision surgery for malreduced lateral plateau fractures

Why This Approach is Chosen:

The anterolateral approach provides direct access to the lateral tibial plateau and metaphysis. It allows placement of a buttress plate on the anterolateral surface to counteract valgus and axial loading forces. Submeniscal arthrotomy permits direct visualization of the articular surface, which is critical for confirming anatomic reduction (goal less than 2 mm step-off). This approach cannot adequately address posterolateral or medial column fractures.

Contraindications:

• Isolated medial or posteromedial fractures (use anteromedial or posteromedial approach)
• Severe soft tissue compromise over the lateral knee (may need delayed surgery or alternative approach)
• Medical unfitness for supine positioning with knee flexion
• Active infection

Alternative Approaches:

• Anteromedial approach: For medial plateau fractures
• Posterolateral approach: For posterolateral column fragments (prone)
• Posteromedial approach: For posteromedial fragments
• Extended lateral with fibular osteotomy: For complex bicondylar fractures requiring combined access

Bony Anatomy:

The lateral tibial plateau forms the lateral condyle of the proximal tibia. The tibial plateau has an inherent 7-10 degree posterior slope. Gerdy's tubercle is the anterolateral insertion of the iliotibial band on the proximal tibia. The fibular head lies posterolateral and is a key landmark for the common peroneal nerve.

Muscular Layers:

Neurovascular Anatomy:

Three-Column Classification of Tibial Plateau:

• Lateral column: Anterolateral approach
• Medial column: Anteromedial or posteromedial approach
• Posterior column (PL + PM): Posterolateral and/or posteromedial approach

The internervous plane for the anterolateral approach is between the anterior compartment (tibialis anterior, supplied by the deep peroneal nerve) and the lateral compartment (peroneus longus, supplied by the superficial peroneal nerve). However, in practice, the approach is performed by subperiosteal elevation of the entire anterior compartment musculature off the lateral metaphysis rather than splitting a true intermuscular plane.

Key Points:

• No true internervous plane is developed between two muscles
• The anterior compartment is elevated as a unit from lateral to medial
• The common peroneal nerve is identified at the fibular neck and protected posterolaterally
• Subperiosteal dissection preserves the periosteal blood supply to the bone
• The approach stays anterior to the fibular head and lateral collateral ligament

Structures Crossing the Plane:

• The common peroneal nerve must be mobilized gently if it crosses the field
• The recurrent genicular vessels are often ligated
• The iliotibial band insertion at Gerdy's tubercle may be partially released for exposure

Standard Position:

• Supine on a radiolucent table
• Small bump or sandbag under the ipsilateral hip to achieve slight internal rotation of the limb
• Knee flexed 30-40 degrees over a radiolucent triangle or bump
• This position relaxes the posterior capsule and improves access to the lateral plateau
• Tourniquet applied high on the thigh (optional but commonly used)

Alternative Positioning:

• Lateral decubitus with affected side up can be used if combined posterior access is anticipated
• Allows combination with posterolateral approach without repositioning in some cases
• Some exposure to the anterior compartment is sacrificed compared to true supine

Equipment Setup:

• Radiolucent table essential for fluoroscopy
• C-arm positioned from the contralateral side
• Headlight or overhead lights for deep visualization
• Standard orthopaedic tray plus specific retractors (Hohmann, Bennett, Senn)

Key Bony Landmarks:

• Gerdy's tubercle - palpable anterolateral prominence on proximal tibia, insertion of ITB
• Fibular head - posterolateral prominence, key for CPN location
• Lateral joint line - palpated with knee in slight flexion
• Tibial crest - anterior midline landmark for distal extension
• Patella and patellar tendon - medial boundary of incision

Key Soft Tissue Landmarks:

• Iliotibial band - palpable as thick band inserting at Gerdy's tubercle
• Common peroneal nerve - can often be palpated wrapping around fibular neck
• Biceps femoris tendon - inserts on fibular head, posterior boundary

Incision Planning:

• Hockey-stick incision: Starts 2-3 cm proximal to joint line, curves anteriorly over Gerdy's tubercle, extends distally along anterior compartment
• Straight lateral incision: Vertical line 1 cm posterior to tibial crest, centered over Gerdy's tubercle
• Length: 8-12 cm depending on exposure required
• Stays anterior to fibular head proximally
• Distal extent stops proximal to anterior tibial artery entry point (5-7 cm)

Layer-by-Layer Danger Structures:

Skin and Subcutaneous Tissue:

• Lateral sural cutaneous nerve branches (sensory only)
• Recurrent genicular vessels (may require ligation)

Fascial Layer:

• Common peroneal nerve at fibular neck (1-2 cm distal to fibular head) - MOST CRITICAL
• Identify by palpation before deep retraction
• Protect with vessel loop or tape sling
• No metal retractors directly on nerve

Anterior Compartment Elevation:

• Anterior tibial artery and vein (enter anterior compartment 5-7 cm distal to joint line)
• Deep peroneal nerve (travels with anterior tibial vessels)
• Stop subperiosteal elevation proximal to vessel entry point

Arthrotomy Layer:

• Lateral inferior genicular artery
• Lateral meniscus (repair if arthrotomy performed)
• Coronary ligament (meniscotibial ligament)

At-Risk Summary Table:

Proximal Extension:

• Extend the incision proximally along the lateral border of the patella
• Develop a lateral parapatellar arthrotomy for intra-articular visualization
• Useful for complex intra-articular fractures or when combined with tibial tubercle osteotomy

Distal Extension:

• Extend the incision distally along the anterior compartment fascia
• Continue subperiosteal elevation of anterior compartment muscles
• Useful for more distal metaphyseal or diaphyseal extension
• Stop before anterior tibial artery entry point unless vessels are identified and protected

Combined Approaches:

• Anterolateral + Posterolateral: For bicondylar fractures with posterolateral fragment (requires repositioning to prone or lateral decubitus)
• Anterolateral + Anteromedial: For bicondylar fractures with medial column involvement (same supine position)
• Anterolateral + Posteromedial: Requires staged positioning (supine then prone or lateral)

Fibular Osteotomy Option:

Rarely needed for pure anterolateral access. Reserved for complex cases where posterolateral access is also required through a single incision (extended lateral approach with fibular neck osteotomy).

Primary Procedures:

• Open reduction and internal fixation of lateral tibial plateau fractures (Schatzker I-III)
• Lateral buttress plating for split and split-depression patterns
• Elevation of depressed articular segments with bone grafting
• Submeniscal arthrotomy and direct articular surface inspection
• Lateral meniscal repair or partial meniscectomy if indicated

Fixation Options:

• 3.5 mm contoured buttress plates (T-plate, L-plate, anatomic proximal tibia plate)
• Locking plate constructs for osteoporotic bone or comminution
• Independent lag screws for split components
• Bone graft or bone graft substitute for metaphyseal voids

Associated Procedures:

• Knee ligament reconstruction (if combined injury)
• Meniscal repair or transplantation
• High tibial osteotomy (rarely combined)

Procedures NOT Performed Through This Approach:

• Posterolateral column fixation (requires posterolateral approach)
• Medial column fixation (requires anteromedial or posteromedial approach)
• Posterior cruciate ligament reconstruction (requires posterior approach)

Layered Closure:

1. Arthrotomy Repair: Repair the coronary ligament (submeniscal arthrotomy) with absorbable sutures (2-0 or 3-0 Vicryl). This reattaches the meniscus to the tibia and restores meniscotibial stability.

2. Iliotibial Band: Repair any partial release or incision in the ITB with absorbable sutures. If a lateral parapatellar arthrotomy was performed, close the retinaculum.

3. Anterior Compartment Fascia: Close loosely with absorbable sutures. Tight closure risks compartment syndrome. Some surgeons leave the fascia open proximally.

4. Subcutaneous Tissue: Close with absorbable sutures in layers to eliminate dead space.

5. Skin: Close with staples, nylon, or absorbable subcuticular suture. Apply sterile dressing.

Post-Closure Checks:

• Document CPN function (ankle dorsiflexion) before leaving operating room
• Check compartment pressures if any concern (especially after prolonged surgery or tourniquet use)
• Apply hinged knee brace or knee immobilizer locked in extension

Drain Usage:

A drain is rarely required but may be used if significant bleeding is anticipated. Remove within 24-48 hours.

Intraoperative Complications:

• Common peroneal nerve injury (3-5 percent) - identify and protect early
• Anterior tibial artery injury - limit distal elevation, careful technique
• Inadequate reduction (greater than 2 mm step-off) - use arthrotomy and fluoroscopy
• Intra-articular hardware placement - confirm with direct visualization and imaging

Early Postoperative Complications:

• Wound dehiscence or infection (2-5 percent, higher with soft tissue compromise)
• Compartment syndrome (rare but possible after anterior compartment elevation)
• Deep vein thrombosis - prophylaxis required
• Loss of reduction if fixation inadequate

Late Complications:

• Post-traumatic osteoarthritis (20-40 percent long-term)
• Knee stiffness - early ROM protocol essential
• Nonunion or malunion (less than 5 percent with proper technique)
• Hardware prominence requiring removal

Failure Management:

• Early loss of reduction: revision ORIF with bone grafting
• Infection: debridement, antibiotics, possible staged revision
• Post-traumatic OA: consider arthroplasty in older patients or osteotomy in younger patients

Immediate Postoperative (0-2 weeks):

• Hinged knee brace locked in extension or knee immobilizer
• Non-weight bearing or toe-touch weight bearing
• Ice, elevation, and DVT prophylaxis
• Wound check at 10-14 days
• Begin gentle knee ROM (0-90 degrees) once wound stable

Early Rehabilitation (2-6 weeks):

• Progressive ROM exercises (goal 0-120 degrees by 6 weeks)
• Quadriceps strengthening
• Continue non-weight bearing or partial weight bearing
• Serial radiographs to monitor reduction

Late Rehabilitation (6-12 weeks):

• Progressive weight bearing as radiographic healing progresses
• Full weight bearing typically by 10-12 weeks
• Advanced strengthening and proprioception
• Return to sport or heavy labor at 4-6 months if radiographic union and full function

Follow-up Imaging:

• Radiographs at 2, 6, and 12 weeks, then 6 and 12 months
• CT if concern about reduction or hardware position

Functional Outcomes:

• Good to excellent results in 70-85 percent of patients with anatomic reduction (less than 2 mm step-off)
• Anatomic reduction is the strongest predictor of long-term outcome
• Lateral split fractures (Schatzker I) have better prognosis than split-depression (Schatzker II)
• Associated meniscal or ligamentous injury worsens prognosis

Radiographic Outcomes:

• Maintenance of reduction in greater than 80 percent with modern plating techniques
• Articular step-off greater than 2 mm associated with early arthritis
• Condylar widening greater than 5 mm associated with poor outcome

Complication Rates:

• Infection: 2-5 percent (higher with open fractures or soft tissue compromise)
• CPN palsy: 3-5 percent (most recover within 12 months)
• Post-traumatic OA: 20-40 percent at 5-10 years
• Reoperation rate: 10-15 percent (hardware removal, revision, arthroplasty)

Global Epidemiology:

Lateral tibial plateau fractures account for approximately 55-65 percent of all tibial plateau fractures worldwide. High-energy mechanisms predominate in younger patients; low-energy falls in elderly osteoporotic patients. The anterolateral approach is the most commonly performed surgical approach for tibial plateau fractures globally.

Guidelines Summary:

• AO Foundation / OTA: Recommends CT-based three-column analysis for all tibial plateau fractures. Anterolateral approach indicated for lateral column involvement with step-off greater than 2 mm or condylar widening greater than 5 mm.
• BOAST (British Orthopaedic Association): Emphasizes soft tissue assessment (wrinkle test) before definitive fixation. Staged management with external fixator if soft tissue compromise present.
• AAOS Appropriate Use Criteria: Supports operative fixation for displaced lateral plateau fractures in active patients. Non-operative management acceptable for non-displaced fractures or low-demand patients.
• EFORT / European Guidelines: Stress importance of anatomic reduction (less than 2 mm step-off) and stable fixation to prevent post-traumatic arthritis. Recommend buttress plating for split-depression patterns.

Registry Evidence:

• NJR (National Joint Registry, UK): Post-traumatic OA after tibial plateau fracture leads to arthroplasty in approximately 5-8 percent of patients within 10 years.
• AJRR (American Joint Replacement Registry): Similar rates; younger patients with malreduced fractures have higher conversion rates.
• AOANJRR (Australian Orthopaedic Association National Joint Replacement Registry): Confirms that anatomic reduction at index surgery reduces long-term arthroplasty risk.

Key Global Practice Points:

• CT is mandatory for surgical planning in all displaced tibial plateau fractures
• Soft tissue timing (wrinkle test) is universal
• Anterolateral approach is standard for lateral column
• Combined approaches for bicondylar fractures require careful positioning planning
• Early ROM and DVT prophylaxis are standard worldwide