Lateral Approach to the Femoral Shaft (Vastus Lateralis)

What it exposes. The lateral approach is the workhorse extensile exposure of the entire femoral shaft, giving direct subperiosteal access to the lateral and posterolateral cortex from the greater trochanter down to the lateral femoral condyle. It is the standard approach for shaft and distal femoral plating, and it is continuous with the lateral distal femoral approach. Why lateral. The lateral surface of the femur is the tension surface and the ideal biomechanical side for a plate, the whole shaft is reachable through one extensile corridor, and the dissection runs through a safe intermuscular plane that avoids the major posterior neurovascular bundle. Approach variants - Standard lateral — the vastus lateralis is elevated anteriorly off the lateral intermuscular septum; the workhorse for shaft and distal femur.

• Submuscular / MIPO — a minimally invasive plate is slid beneath the vastus lateralis along the septum through small proximal and distal incisions, preserving the fracture haematoma and soft-tissue envelope for biological plating of comminuted fractures.
• Extended lateral — continuous proximally with the subtrochanteric corridor and distally with the lateral distal femoral approach for condylar and supracondylar fractures. Position & landmarks. Position the patient supine on a radiolucent table with a sandbag under the ipsilateral buttock, which rolls the limb into slight internal rotation and brings the lateral femur forward. The entire leg is free-draped to allow manipulation and rotation, and a radiolucent table lets the whole shaft be imaged with the image intensifier (C-arm). Flex the knee over a bolster to relax the quadriceps and make elevation of the vastus lateralis easier. A tourniquet is optional; for shaft work exsanguination is often omitted so that bleeding perforators remain visible rather than being hidden by a bloodless field that refills on release. Lateral decubitus is a reasonable alternative, particularly for distal femoral extensions. Palpate and mark the greater trochanter (proximal landmark), the lateral femoral condyle (distal landmark), the linea aspera (the posterior midline ridge approached from the lateral side), and the iliotibial tract and fascia lata (the tight lateral band). The internervous plane. The classical internervous plane lies between the vastus lateralis (supplied by the femoral nerve, anterior compartment) and the short head of biceps femoris (supplied by the tibial part of the sciatic nerve, posterior compartment). Practically the dissection is developed by elevating the vastus lateralis anteriorly off the lateral intermuscular septum rather than by splitting the muscle belly. There is no true classical internervous plane at the septum itself; the safe intermuscular interval between the vastus lateralis and the septum is what is exploited to reach the linea aspera. Applied anatomy that makes the approach make sense. The thigh has three fascial compartments separated by intermuscular septa: the anterior (quadriceps, femoral nerve), the posterior (hamstrings, sciatic nerve), and the medial (adductors, obturator nerve). The lateral intermuscular septum is a strong fascial band running from the deep surface of the fascia lata to the linea aspera and the supracondylar line, separating the anterior from the posterior compartment. The vastus lateralis arises from the greater trochanter, the lateral lip of the linea aspera, and the lateral intermuscular septum itself — which is exactly why it is reflected off the septum rather than split. Its nerve and blood supply enter the muscle anteriorly and from above, so splitting it would denervate and devascularise the posterior fibres. The profunda femoris runs deep to the adductor longus, lying posterior to the femoral shaft; its perforating branches pass behind the femur, traverse the adductor muscles, and pierce the lateral intermuscular septum to supply the hamstrings and enter the vastus lateralis — the very vessels that must be controlled.

Work down through the layers along the lateral thigh, incising the fascia lata, finding the posterior border of the vastus lateralis, then developing the safe intermuscular plane immediately anterior to the lateral intermuscular septum — coagulating each perforator as it is encountered — until the linea aspera is reached and the cortex exposed subperiosteally.

Structures at risk, by level

The perforators — the key bleeding pitfall. The profunda femoris gives off typically four perforating branches that pass posterior to the femur, pierce the adductor magnus and the lateral intermuscular septum, and enter the vastus lateralis. They are the principal blood supply to the hamstrings and part of the quadriceps. Because they traverse the very plane being dissected, an avulsed perforator retracts into the muscle and bleeds vigorously from the profunda system. The disciplined habit is to identify, coagulate and divide each perforator deliberately as the septum is exposed, rather than tearing blindly through it. This single step prevents the majority of the intra-operative bleeding associated with the approach. Deep safety principles. Two habits keep the deeper neurovascular structures out of danger: remain subperiosteal on the linea aspera (a periosteal elevator kept hard on bone separates the dissection from the profunda and its perforators), and do not stray posterior to the femur (in proximal extension the sciatic nerve crosses deep to the long head of biceps and the short external rotators; staying on the lateral and anterior aspect of the bone and avoiding posterior retraction protects it). Use blunt dissection to develop the intermuscular plane, reserving sharp dissection for the controlled division of a clearly identified perforator, and periodically reassess with the image intensifier to confirm the level of the dissection and the position of the fracture and implant. Extensile range. The great strength of the lateral approach is that it is extensile along the entire length of the femur, from the greater trochanter to the lateral femoral condyle, so a single corridor can address pathology at almost any level of the shaft.

Proximal extension (subtrochanteric). For subtrochanteric fractures the incision is extended proximally along the line of the femur toward the greater trochanter. The vastus lateralis continues to be swept anteriorly from the septum, and the gluteus medius and minimus may be encountered as the trochanteric region is approached. Stay on bone and remain anterior to the short external rotators to keep clear of the sciatic nerve, which crosses deep in this region. This is also the corridor used to apply a proximal femoral plate or to access a subtrochanteric nonunion for grafting. Distal extension (distal femur / supracondylar). For distal femoral and supracondylar work the incision is carried distally toward the lateral femoral condyle, remaining anterior to the origin of the gastrocnemius and staying on bone. The superior lateral genicular vessels cross the field and are ligated. The approach becomes continuous with the lateral distal femoral approach, allowing the capsule to be opened if the joint surface must be visualised and a pre-contoured locking condylar plate to be applied along the lateral surface of the distal femur. This is the same corridor used for distal femoral ORIF. Closure. Achieve meticulous haemostasis, re-checking every perforator stump before closing, and irrigate copiously. Place a deep drain beneath the vastus lateralis, because the dead space is large and haematoma is common. Close the fascia lata as a separate layer with absorbable suture, then close subcutaneous tissue and skin in layers.

Post-operative care and rehabilitation. Observe the neurovascular status of the limb. Early knee range of motion is encouraged to prevent quadriceps adhesions — the most important functional limitation after this approach. Weight bearing is progressed according to fixation stability: bridging constructs for comminuted fractures are protected with restricted or touch weight bearing until callus appears, while stable compression-plated patterns may progress more quickly. Quadriceps-strengthening (straight-leg raises, progressing to resisted extension) is central, because the vastus lateralis has been elevated from its origin and must recover. Continue thromboprophylaxis (mechanical and chemical) until the patient is fully mobile, and follow with serial radiographs to confirm alignment, length, rotation and union.

• Plating of femoral shaft fractures — bridge or compression plating for simple and comminuted patterns.
• ORIF of distal femur fractures — using locking distal femoral plates.
• Subtrochanteric fracture plating — via proximal extension.
• Bone grafting — autograft or allograft for defects, nonunions, or after tumour resection.
• Treatment of nonunion and malunion — debridement, realignment, grafting and revision fixation.
• Corrective osteotomy — for angular deformity.
• Tumour and infection — biopsy, excision and debridement of the femoral shaft.
• Biological / MIPO plating — for comminuted shaft fractures the same lateral route is used in a submuscular fashion, sliding the plate beneath the vastus lateralis along the septum to preserve the soft-tissue envelope and fracture haematoma. A note on nail versus plate. Intramedullary nailing remains the gold standard for most diaphyseal shaft fractures. The lateral plating approach is reserved for specific indications, including periprosthetic fractures, femurs with an excessive bow, shaft fractures associated with vascular injury requiring exposure, very proximal or distal fractures, and the paediatric population where the physis must be protected.

Guidelines, registries and global practice. The lateral approach to the femoral shaft is a universal, AO-taught workhorse exposure. Its principles — anterior elevation of the vastus lateralis off the lateral intermuscular septum, deliberate control of the perforating branches of the profunda femoris, and subperiosteal access to the linea aspera — are consistent across examination systems and trauma teaching worldwide. Side-by-side principles (where guidance converges): | Body | Position on femoral shaft plating | |------|-----------------------------------| | AO Foundation | The lateral approach is the standard exposure for diaphyseal and distal femoral plating; biological and MIPO variants are preferred for comminuted shaft fractures to preserve vascularity | | BOA and BOAST | Early fixation of femoral shaft fractures in polytrauma with an emphasis on soft-tissue-preserving techniques | | OTA and AAOS | Restoration of length, rotation and alignment as the primary goals, with bridge plating for comminuted patterns | Global practice variation: In high-resource settings, pre-contoured locking plates and submuscular MIPO techniques are standard for distal femoral and selected shaft fractures. In resource-limited settings, the same lateral corridor is used with standard broad dynamic compression or limited-contact plates applied through an open technique. Intramedullary nailing remains the default for most diaphyseal shaft fractures, with plating reserved for specific indications such as periprosthetic fractures, femurs with an excessive bow, shaft fractures with vascular injury, and very proximal or distal extensions. Consent (globally applicable): discuss bleeding from the perforating branches of the profunda femoris, infection, haematoma requiring drainage, quadriceps weakness and adhesions, heterotopic ossification, deep vein thrombosis, and the rare need for revision surgery or nonunion repair.