import { ComparisonTable, ContentSection, EvidenceCard, ExamCheatSheet, ExamPearl, ExamWarning, InfoCard, InfoCardGrid, MedicalImage, MnemonicCard, OnePagerSummary, SafetyAlert, Tab, Tabs, Timeline, TimelineItem, VivaScenario, VivaScenarioSection } from '@/components/mdx' Injury to femoral vessels due to failure to identify subsartorial canal anatomy. Damage to saphenous nerve during proximal dissection without proper identification. Compartment syndrome from excessive retraction of vastus medialis. Fracture devascularization from circumferential periosteal stripping. Subsartorial (Hunter's) canal boundaries: vastus medialis (lateral wall), adductor longus and magnus (medial wall), sartorius and fascial roof (anterior wall). Saphenous nerve exits canal at mid-thigh by piercing fascial roof. Femoral vessels enter canal proximally at apex of femoral triangle. Why is this not a true internervous plane? Both muscles are femoral nerve innervated, but functionally distinct with minimal morbidity from dissection. What structures are at risk? Femoral vessels, saphenous nerve, perforating vessels. When would you choose medial over lateral approach? Previous lateral surgery, medial pathology, MIPO techniques, combined vascular procedures. Position patient supine with hip slightly abducted and externally rotated. Incise skin and deep fascia over medial thigh. Identify sartorius and retract medially to expose vastus medialis. Open subsartorial fascial roof to identify and protect femoral vessels. Elevate vastus medialis laterally to expose medial femoral shaft. The **anteromedial approach to the femur** provides access to the medial femoral shaft through the interval between **sartorius (medial) and vastus medialis (lateral)**—both femoral nerve-innervated, making this a **functional but not true internervous plane**. Key indications include MIPO distal femur fractures (95% union rate), medial plating, nonunion bone grafting, and revision surgery with previous lateral scarring. The **subsartorial (Hunter's) canal** contains the femoral vessels and must be identified to avoid catastrophic injury; boundaries are sartorius (roof), vastus medialis (lateral), and adductors (medial). The **saphenous nerve** exits the canal at mid-thigh and is the most commonly injured structure (5-15% risk). Position the patient supine with hip slightly abducted and externally rotated. The anteromedial approach to the femur is a versatile surgical corridor that provides direct access to the medial and anterior aspects of the femoral shaft. While technically not a true internervous plane (both sartorius and vastus medialis are innervated by the femoral nerve), the approach is considered safe because the dissection occurs between functionally distinct muscles with different roles. The sartorius acts primarily as a hip flexor and knee flexor, while the vastus medialis is a powerful knee extensor. This approach has gained popularity in modern trauma surgery, particularly for minimally invasive plate osteosynthesis (MIPO) techniques and for complex cases where the lateral aspect of the femur has been previously operated on or is unsuitable for fixation. The superficial nature of the dissection, combined with the relatively avascular plane, makes it an attractive option for surgeons dealing with femoral shaft pathology. The femoral neurovascular bundle is the critical structure at risk during this approach. The bundle consists of the femoral artery (lateral), femoral vein (intermediate), and femoral nerve (most lateral), with the relationship remembered by the mnemonic NAVEL (from lateral to medial: Nerve, Artery, Vein, Empty space, Lymphatics). In the mid-thigh, these structures course through the subsartorial (Hunter's) canal, bounded by vastus medialis laterally, adductor longus and magnus medially, and sartorius superficially. ### Historical Context and Evolution The anteromedial approach to the femur has evolved significantly over the past several decades, driven by advances in fracture fixation techniques and understanding of fracture biology. Traditional open plating techniques involved extensive soft tissue dissection and periosteal stripping, which compromised fracture healing. The development of minimally invasive plate osteosynthesis (MIPO) techniques in the 1990s revolutionized the use of the anteromedial approach, allowing surgeons to achieve stable fixation while preserving the biologic environment necessary for fracture healing. The anatomical basis for the anteromedial approach has been well-described in classical surgical anatomy texts. While the approach is sometimes referred to as an "internervous plane," this is technically a misnomer because both sartorius and vastus medialis are innervated by branches of the femoral nerve. However, the functional distinction between these muscles (sartorius as a hip flexor and vastus medialis as a knee extensor) means that dissection between them does not result in significant functional morbidity. ### Primary Indications **Trauma Applications:** The anteromedial approach is indicated for femoral shaft fractures requiring medial plate fixation, particularly in the middle third of the shaft. This may be necessary when the lateral aspect of the femur is unsuitable for fixation due to comminution, bone loss, or soft tissue injury. The approach is also useful for managing femoral shaft fractures in patients with ipsilateral vascular injuries, as it provides direct access to the femoral vessels for combined orthopedic and vascular procedures. In the context of polytrauma, the anteromedial approach may be preferred when the patient requires simultaneous vascular repair and skeletal stabilization. The approach allows both the orthopedic and vascular teams to work through the same surgical field, reducing overall surgical time and minimizing additional soft tissue trauma. This is particularly relevant in damage control orthopedics scenarios where minimizing physiologic insult is paramount. Minimally invasive plate osteosynthesis (MIPO) techniques for distal femoral fractures frequently utilize the anteromedial approach for submuscular plate insertion. The approach allows for indirect fracture reduction and biologic fixation while preserving the fracture hematoma and soft tissue attachments. Studies have demonstrated excellent union rates and functional outcomes with MIPO techniques using this approach. Periprosthetic femur fractures around total hip arthroplasty stems, classified as Vancouver B1 fractures (stem stable, fracture around or just below stem), may benefit from the anteromedial approach when medial plate fixation is planned. The approach avoids the gluteus medius and abductors laterally, which may be compromised from previous surgery, and provides access to virgin tissue planes medially. **Reconstructive Applications:** Atrophic nonunions of the femoral shaft requiring bone grafting are well-served by the anteromedial approach. The approach allows for takedown of the nonunion site, removal of interposed soft tissue, and application of autograft or allograft bone. Medial plating can be performed simultaneously to provide mechanical stability. The approach is particularly useful when previous lateral surgery has resulted in scarring or soft tissue compromise. Femoral shaft malunions requiring corrective osteotomy may utilize the anteromedial approach when medial-based correction is planned. The approach provides excellent visualization of the femoral shaft and allows for precise osteotomy placement and fixation. Combined rotational and angulatory corrections can be performed through this approach with appropriate preoperative planning and instrumentation. Bone biopsy and tumor excision of medial femoral lesions represent important indications for the anteromedial approach. Benign tumors such as osteochondroma, fibrous dysplasia, or enchondroma can be accessed and excised through this approach. Malignant tumors requiring wide excision with preservation of neurovascular structures may also benefit from this approach, particularly when combined with limb salvage reconstruction. ### Contraindications **Absolute Contraindications:** Active infection in the surgical field, including cellulitis, abscess, or open wound, represents an absolute contraindication to elective surgery through the anteromedial approach. In acute trauma scenarios, grossly contaminated medial thigh wounds may necessitate debridement and alternative approaches for skeletal fixation. Staged protocols with temporary external fixation should be considered. Vascular insufficiency with threatened limb viability is a relative absolute contraindication, as surgical trauma may compromise already tenuous blood supply. However, in cases of acute vascular injury requiring combined procedures, this becomes an indication rather than contraindication. Preoperative vascular assessment with ankle-brachial indices (ABI) and possible CT angiography is recommended in high-risk patients. **Relative Contraindications:** Massive medial soft tissue loss or injury may make the anteromedial approach unfavorable due to concerns about wound healing and soft tissue coverage. Alternative approaches such as the lateral or anterolateral approach should be considered. If the anteromedial approach is necessary despite soft tissue compromise, plastic surgery consultation for flap coverage may be required. Morbid obesity presents technical challenges for the anteromedial approach due to difficulty in patient positioning, increased depth of the surgical field, and challenges with retraction. While not an absolute contraindication, obese patients may be better served by alternative approaches with more superficial anatomy. If the anteromedial approach is selected, appropriate deep retractors and extended-length instruments should be available. ### Surface Anatomy and Landmarks The anterior superior iliac spine (ASIS) and pubic tubercle define the inguinal ligament, beneath which the femoral vessels exit the pelvis. The femoral pulse is palpable at the mid-inguinal point (midpoint between ASIS and pubic symphysis), which corresponds to the femoral artery's location as it enters the femoral triangle. This is distinct from the midpoint of the inguinal ligament, which marks the deep inguinal ring. The adductor tubercle is palpable on the medial femoral condyle and serves as the distal landmark for the approach. The medial supracondylar line can be followed proximally from this tubercle. The medial border of the patella provides a useful reference point when the knee is flexed to 90 degrees, with the surgical incision typically centered between the ASIS and adductor tubercle. In thin patients, the sartorius muscle belly may be visible or palpable as it crosses obliquely from lateral to medial across the anterior thigh. The muscle forms the lateral border of the femoral triangle proximally and can be traced distally toward its insertion on the pes anserinus. The vastus medialis is palpable as a bulge on the anteromedial aspect of the distal thigh, particularly when the patient actively extends the knee against resistance. ### Muscular Anatomy **Sartorius Muscle:** The sartorius is the longest muscle in the human body, running obliquely across the anterior thigh from the ASIS to the medial aspect of the proximal tibia. It originates from the ASIS and adjacent anterior part of the ilium, and inserts on the superior medial surface of the tibial shaft as part of the pes anserinus (along with gracilis and semitendinosus). The muscle is innervated by the femoral nerve (L2-L3) via branches that enter its deep surface in the proximal thigh. Functionally, sartorius flexes, abducts, and externally rotates the hip, while also flexing and internally rotating the knee. This combination of actions is used when crossing one leg over the other, hence its name from the Latin "sartor" meaning tailor. During the anteromedial approach, the sartorius is identified by its strap-like appearance and oblique course, and is typically retracted medially to access the deeper structures. **Vastus Medialis:** Vastus medialis is the most medial of the four quadriceps muscles and plays a crucial role in knee extension, particularly in the terminal degrees of extension. The muscle originates from the lower portion of the intertrochanteric line, the medial lip of the linea aspera, the medial supracondylar line, and the medial intermuscular septum. It inserts into the quadriceps tendon and the medial aspect of the patella via the medial retinaculum. The muscle is innervated by the femoral nerve (L2-L4) via branches that enter its deep and lateral surface. The nerve supply enters from the lateral side, which is important during the anteromedial approach because medial dissection and elevation of the muscle does not denervate it. The vastus medialis has two distinct portions: the vastus medialis longus (VML) and vastus medialis obliquus (VMO), with the latter being particularly important for patellar tracking. ### Neurovascular Anatomy **Femoral Nerve and Saphenous Nerve:** The femoral nerve (L2-L4) is the largest branch of the lumbar plexus and enters the thigh beneath the inguinal ligament, lateral to the femoral artery. In the femoral triangle, the nerve divides into anterior and posterior divisions, giving off multiple motor and sensory branches. The motor branches supply all four quadriceps muscles (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis) and sartorius. The saphenous nerve is the largest and longest cutaneous branch of the femoral nerve, providing sensory innervation to the medial leg and foot. The nerve arises from the posterior division of the femoral nerve in the femoral triangle and descends through the subsartorial canal, lying lateral to the femoral artery. At approximately the mid-thigh level, the saphenous nerve pierces the fascial roof of the canal (formed by the overlying sartorius and fascia) to become subcutaneous. During the anteromedial approach, the saphenous nerve is at risk during two key steps: (1) when opening the fascial roof of the subsartorial canal to access the femoral vessels, and (2) during distal extension of the approach. The nerve should be identified, carefully mobilized, and protected throughout the procedure. **Femoral Vessels:** The femoral artery is the continuation of the external iliac artery as it passes beneath the inguinal ligament at the mid-inguinal point. In the femoral triangle, the artery gives off superficial branches (superficial epigastric, superficial circumflex iliac, and superficial external pudendal) and the deep profunda femoris artery. The profunda femoris is the major blood supply to the thigh musculature and gives off medial and lateral circumflex femoral arteries, as well as three to four perforating arteries. The femoral artery continues distally through the subsartorial canal, lying anteromedial to the femur. The femoral vein lies medial to the femoral artery in the femoral triangle and continues through the subsartorial canal in a similar medial relationship. The vein is larger and thinner-walled than the artery, making it more vulnerable to iatrogenic injury during dissection. **Perforating Arteries:** The profunda femoris artery gives off three to four perforating arteries that pierce the adductor magnus muscle to supply the posterior compartment of the thigh. These perforating vessels are encountered during deep dissection in the anteromedial approach and must be carefully protected or ligated. The first perforating artery is typically encountered 5-7 cm distal to the lesser trochanter and is the largest of the perforating vessels. Injury to these vessels can result in significant bleeding and hematoma formation, though they can generally be controlled with ligation without compromising limb perfusion. ### Not a True Internervous Plane The anteromedial approach is commonly described as utilizing an "internervous plane" between sartorius and vastus medialis. However, this is technically inaccurate because both muscles are innervated by the femoral nerve. The term "internervous plane" traditionally refers to a plane between muscles supplied by different nerves, such that dissection in this plane does not denervate any muscles and therefore minimizes functional morbidity. Despite this technical inaccuracy, the anteromedial approach is considered safe and functionally sound for several reasons. First, the nerve branches to sartorius and vastus medialis arise separately from the femoral nerve and enter the muscles from different directions (sartorius from deep surface, vastus medialis from lateral surface). Second, the muscles are functionally distinct, with sartorius primarily functioning as a hip flexor while vastus medialis is a knee extensor. The concept is better described as an "intermuscular plane" or "functional internervous plane" to acknowledge the anatomical reality while emphasizing the clinical safety. In viva examinations, candidates should demonstrate understanding of this nuance and explain why the approach remains safe despite not being a true internervous plane. The anteromedial approach is safe even though both muscles share femoral nerve innervation because: (1) nerve branches enter from different directions, (2) muscles have different functions (hip flexion vs knee extension), (3) medial elevation preserves lateral nerve entry to vastus medialis. ### Operating Room Setup The patient is positioned supine on a radiolucent operating table, which is essential for intraoperative fluoroscopic imaging. Standard fracture tables are generally not required for the anteromedial approach, as manual traction and positioning are typically sufficient. However, a radiolucent triangle or bump may be placed under the ipsilateral hip to facilitate hip abduction and external rotation, improving access to the medial thigh. The operating room should be set up to allow fluoroscopic imaging in both anteroposterior and lateral planes. The C-arm should be positioned to come from the contralateral side of the patient, allowing for unrestricted access to the surgical field while maintaining the ability to obtain high-quality fluoroscopic images. All members of the surgical team should wear lead aprons and thyroid shields, and the operating room should have appropriate radiation monitoring badges available. Instrumentation for the anteromedial approach should include standard orthopedic trauma sets with periosteal elevators, reduction clamps, and retractors. For MIPO techniques, specialized instruments including submuscular tunneling devices and percutaneous screw insertion guides are essential. Long-handled instruments may be necessary in obese patients to achieve adequate depth in the surgical field. A vascular tray should be immediately available in case of inadvertent vascular injury, including vascular clamps, vessel loops, and fine vascular sutures. The entire lower extremity from the iliac crest to the toes should be prepped and draped into the surgical field. This allows for manipulation of the limb during the procedure and provides access to alternative surgical sites if complications arise. The contralateral limb should be positioned in slight abduction to prevent inadvertent pressure injuries from leg-to-leg contact during the procedure. ### Positioning Details The operative limb is positioned with the hip slightly abducted (15-20 degrees) and externally rotated (10-15 degrees). This position brings the medial aspect of the thigh anteriorly and facilitates access to the surgical corridor between sartorius and vastus medialis. The knee should be flexed 10-20 degrees and supported on a sterile bump or rolled towels to relax the quadriceps and hamstring muscles. A radiolucent triangle or bump under the ipsilateral buttock helps maintain hip abduction and external rotation without requiring continuous manual positioning. The bump should be positioned to tilt the pelvis slightly, rotating the operative hemipelvis posteriorly. All bony prominences should be adequately padded, with particular attention to the sacrum, heel, and contralateral fibular head to prevent pressure injuries during potentially prolonged procedures. **Anesthesia Considerations:** General anesthesia is typically preferred for the anteromedial approach, as it allows for optimal muscle relaxation and facilitates manipulation of the limb during fracture reduction. However, regional anesthesia with neuraxial blockade (spinal or epidural) can be used in select patients, particularly elderly patients with significant cardiac or pulmonary comorbidities. The use of regional anesthesia provides excellent postoperative pain control and may reduce perioperative complications in high-risk patients. For MIPO procedures where minimal soft tissue dissection is anticipated, regional anesthesia may be particularly advantageous. The use of peripheral nerve blocks (femoral nerve block or adductor canal block) can provide targeted analgesia while preserving motor function, facilitating early mobilization in the postoperative period. Communication between the surgical and anesthesia teams is essential to coordinate the timing of regional blocks with the surgical approach, as pre-operative femoral nerve blocks may interfere with identification of anatomical landmarks. ### Skin Incision The skin incision is planned longitudinally over the medial aspect of the thigh, centered between the ASIS proximally and the adductor tubercle distally. The incision typically begins 8-10 cm distal to the ASIS and extends distally for 15-20 cm, depending on the required exposure. For MIPO techniques, a shorter incision (8-10 cm) may be sufficient, while extensive exposures for tumor excision or revision surgery may require longer incisions. The incision should be placed slightly posterior to the midline of the medial thigh to avoid the great saphenous vein, which runs along the more anterior aspect of the medial thigh. The skin should be incised with a scalpel blade perpendicular to the skin surface to create clean wound edges that facilitate closure. ### Deep Fascia Incision The deep fascia (fascia lata) is identified as a white, glistening layer overlying the muscle compartments. The fascia should be incised sharply with a scalpel blade in line with the skin incision. After incising the fascia, the underlying sartorius muscle is identified by its strap-like morphology and oblique course from lateral-proximal to medial-distal. Avoid the great saphenous vein by placing the incision slightly posterior to the anterior midline of the medial thigh. Inadvertent vein injury causes troublesome bleeding and increases hematoma risk. ### Muscular Interval The sartorius muscle is identified by its strap-like appearance and oblique course. The muscle should be traced proximally toward its origin at the ASIS and distally toward its insertion on the pes anserinus. The vastus medialis is identified lateral to the sartorius as a bulkier, more muscular structure with vertical fibers. Once both muscles are clearly identified, the sartorius is retracted medially (anteriorly) using a handheld or self-retaining retractor. This exposes the underlying vastus medialis and provides access to the subsartorial canal, which lies deep to the sartorius. ### Opening Subsartorial Canal With the sartorius retracted medially, the fascial roof of the subsartorial (Hunter's) canal is identified. This fascia is a distinct layer that spans between sartorius superficially and the underlying adductor muscles medially. The fascia should be incised carefully under direct vision, as the femoral vessels lie immediately beneath it. The canal is opened by incising the fascial roof with Metzenbaum scissors or a scalpel blade. Once the canal is opened, the femoral artery and vein are identified and carefully mobilized medially using gentle blunt dissection. The saphenous nerve, lying lateral to the artery, should be identified, mobilized, and protected with a vessel loop or rubber sling. The saphenous nerve is the most commonly injured structure. Identify it early when opening the subsartorial canal, use a vessel loop for gentle retraction, and reposition retractors frequently to avoid compression injury. ### Femoral Shaft Exposure With the neurovascular structures identified and protected, the vastus medialis is elevated from the medial aspect of the femur using subperiosteal dissection. The muscle's origin from the medial lip of the linea aspera is encountered and must be carefully elevated to expose the bone. Periosteal elevators (such as Cobb or Key elevators) are used to strip the muscle from the femoral shaft in a controlled, subperiosteal manner. The extent of periosteal stripping should be limited to only what is necessary for the planned procedure. In fracture cases, excessive periosteal stripping devascularizes fracture fragments and impairs healing. ### MIPO Technique For MIPO procedures, a submuscular tunnel is created by elevating vastus medialis from the femoral shaft using a periosteal elevator or specialized MIPO instruments. The tunnel extends proximally and distally from the limited incision, creating a space for plate insertion. The plate is typically inserted from distal to proximal, sliding beneath the vastus medialis muscle while maintaining its soft tissue attachments. In MIPO technique, do NOT expose or strip the fracture site. Preserve the fracture hematoma and soft tissue attachments. Use indirect reduction and submuscular plate insertion to maintain biology. ### Hemostasis Meticulous hemostasis is essential before closure to prevent hematoma formation. The surgical field should be thoroughly inspected and all bleeding vessels controlled with bipolar electrocautery or suture ligation. The subsartorial canal should be inspected to ensure that the femoral vessels are intact and that no hematoma is forming around the neurovascular bundle. ### Layer Closure The deep fascia (fascia lata) is closed with running or interrupted absorbable sutures (0 or 1 Vicryl). The subsartorial canal does not require formal closure, as the fascial roof is thin and closure may compress the neurovascular structures. The sartorius muscle is allowed to fall back into its anatomical position, providing soft tissue coverage over the femoral vessels. The subcutaneous tissue is closed in one or more layers using absorbable sutures (2-0 or 3-0 Vicryl). Skin closure options include staples, interrupted nonabsorbable sutures, running subcuticular absorbable sutures, or tissue adhesive. A sterile dressing is applied to protect the wound and provide compression to minimize hematoma formation. ### Neurovascular Complications **Saphenous Nerve:** The saphenous nerve is the most commonly injured structure during the anteromedial approach. Injury can occur through direct laceration, excessive traction, compression by retractors, or thermal injury from electrocautery. Saphenous nerve injury results in numbness or dysesthesias over the medial leg and foot. While this is generally well-tolerated, some patients find the numbness bothersome, particularly when wearing boots or when kneeling. Prevention of saphenous nerve injury requires identification and protection of the nerve before proceeding with dissection. The nerve should be identified when opening the subsartorial canal and mobilized carefully with a vessel loop or rubber sling. Retractors should be placed under direct vision and repositioned frequently to avoid prolonged nerve compression. **Femoral Vessels:** Injury to the femoral artery or vein is the most serious potential complication of the anteromedial approach. The femoral vessels lie in the subsartorial canal, directly in the path of dissection, and can be injured during opening of the canal, retractor placement, or overzealous dissection. Arterial injury typically presents with pulsatile bleeding, expanding hematoma, or loss of distal pulses. Immediate management includes direct pressure, proximal and distal control of the vessel, and urgent vascular surgery consultation. Prevention of vascular injury requires thorough knowledge of anatomy, careful dissection under direct vision, and protective retraction of vessels during the procedure. ### Postoperative Complications **Hematoma Formation:** Postoperative hematoma can occur despite careful hemostasis and results in wound swelling, pain, and potential infection. Small hematomas may reabsorb spontaneously and can be managed conservatively. Larger hematomas may require drainage to prevent wound dehiscence or infection. Prevention of hematoma includes meticulous hemostasis, consideration of drain placement, appropriate postoperative compression dressing, and judicious use of anticoagulation in the immediate postoperative period. In patients requiring thromboprophylaxis, consideration should be given to delaying the first dose of anticoagulation for 6-12 hours postoperatively to allow for initial hemostasis. The use of tranexamic acid (TXA) may reduce bleeding and hematoma formation in high-risk patients, though its use should be balanced against thromboembolic risk. **Infection:** Surgical site infection following the anteromedial approach occurs in approximately 1-3% of cases. Superficial infections involving only the skin and subcutaneous tissue can often be managed with antibiotics alone, while deep infections involving the fascia or bone require surgical debridement. Risk factors for infection include diabetes, smoking, obesity, prolonged operative time, and inadequate antibiotic prophylaxis. Prevention strategies include appropriate preoperative antibiotic prophylaxis (cefazolin 2g IV within 60 minutes of incision), maintenance of normothermia during surgery, gentle soft tissue handling, and meticulous hemostasis to prevent hematoma formation. In cases of open fractures or grossly contaminated wounds, staged procedures with temporary external fixation should be considered to reduce infection risk. **Compartment Syndrome:** Acute compartment syndrome is a surgical emergency characterized by increased pressure within a closed fascial compartment, leading to decreased perfusion and potential muscle and nerve necrosis. While less common after the anteromedial approach compared to lateral approaches, compartment syndrome can occur due to hematoma, excessive soft tissue trauma, or prolonged retraction during surgery. Treatment of compartment syndrome requires urgent four-compartment fasciotomy of the thigh. Prevention requires awareness of risk factors, careful surgical technique, and high index of suspicion in the postoperative period. ### Immediate Postoperative Care Postoperative management following the anteromedial approach focuses on pain control, wound care, and prevention of complications. Patients should be monitored closely in the recovery room for signs of neurovascular compromise, including loss of distal pulses, progressive numbness beyond the expected saphenous nerve distribution, or severe unremitting pain suggesting compartment syndrome. The wound should be inspected for signs of hematoma formation or excessive drainage, and the dressing should provide appropriate compression without constricting circulation. Pain management typically involves a multimodal approach combining opioid and non-opioid analgesics. Regional anesthesia techniques such as femoral nerve blocks or adductor canal blocks can provide excellent pain control in the immediate postoperative period while minimizing opioid requirements and associated side effects. Non-steroidal anti-inflammatory drugs (NSAIDs) should be used judiciously, particularly in patients with fracture nonunion or delayed union, as some evidence suggests they may impair bone healing. ### Weight-Bearing and Mobilization Weight-bearing restrictions following the anteromedial approach depend on the underlying pathology and the stability of the surgical construct. For MIPO fixation of distal femoral fractures, patients typically begin with toe-touch weight bearing for the first 6-12 weeks, progressing to partial weight bearing as radiographic evidence of healing appears. Full weight bearing is generally permitted at 12 weeks if adequate callus formation is evident on radiographs. For periprosthetic fracture fixation around stable hip stems (Vancouver B1), early mobilization with partial weight bearing may be permitted if the construct is stable, though surgeon judgment is essential. Atrophic nonunions treated with bone grafting and medial plating typically require prolonged protected weight bearing (12 weeks or more) to allow for graft incorporation and fracture union. Physical therapy should begin on the first postoperative day with passive and active range of motion exercises, progressing to strengthening and functional training as healing permits. ### Radiographic Follow-Up Serial radiographs are essential to monitor fracture healing and identify complications. The typical follow-up schedule includes radiographs at 2 weeks, 6 weeks, 12 weeks, and 6 months postoperatively. At each visit, radiographs should be carefully evaluated for signs of fracture union (bridging callus across three of four cortices on orthogonal views), hardware failure (screw loosening, plate breakage), loss of reduction, or other complications. Delayed union or nonunion may require additional interventions such as bone stimulation, revision fixation, or bone grafting. ### Return to Function The timeline for return to full function varies based on the underlying pathology and patient factors. For simple fractures in young patients with good bone quality, return to full activities of daily living typically occurs by 3-4 months postoperatively. Return to demanding physical activities, including manual labor or competitive sports, generally requires 6-12 months and should be guided by radiographic evidence of complete fracture union and clinical assessment of strength and function. Elderly patients with periprosthetic fractures or those with multiple comorbidities may have longer recovery trajectories and should have individualized rehabilitation plans that account for their overall medical status and functional goals. Coordination with physiotherapy, occupational therapy, and geriatric medicine services may be beneficial in optimizing functional outcomes in this population. **Q: Why is the anteromedial approach to the femur NOT a true internervous plane?** A: **Both sartorius and vastus medialis are innervated by the femoral nerve**. However, it remains a functionally safe interval because sartorius primarily acts as a hip flexor while vastus medialis is a knee extensor, so dissection between them causes minimal functional deficit. **Q: What are the anatomical boundaries of the subsartorial (Hunter's) canal?** A: **Lateral wall**: Vastus medialis. **Medial wall**: Adductor longus (proximally) and adductor magnus (distally). **Roof**: Sartorius muscle and fascial covering (vastoadductor membrane). Contents include femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis. **Q: What structure is MOST commonly injured during the anteromedial approach to the femur?** A: **Saphenous nerve**. It exits the subsartorial canal at mid-thigh by piercing the fascial roof between sartorius and gracilis. It must be identified and protected during proximal dissection. Injury causes sensory loss over the medial leg and can cause painful neuroma. **Q: What is the lateral-to-medial arrangement of structures at the base of the femoral triangle?** A: **NAVEL** - Nerve (femoral), Artery (femoral), Vein (femoral), Empty space, Lymphatics. The femoral nerve lies most lateral under the iliacus fascia, while lymphatics lie most medial in the femoral canal (site of femoral hernia). Within the Australian healthcare system, the anteromedial approach is increasingly utilized for periprosthetic fractures, reflecting the aging population and high rates of total hip arthroplasty. The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) reports over 60,000 primary hip replacements performed annually, with a corresponding increase in periprosthetic fractures requiring surgical management. Vancouver B1 fractures represent approximately 25-30% of periprosthetic femur fractures, with revision rates of approximately 5-8% at 5 years when treated with open reduction and internal fixation. Australian trauma networks emphasize the importance of vascular surgery availability when performing this approach in polytrauma patients, given the proximity to major vessels. Regional centers should have protocols for immediate vascular consultation if iatrogenic injury occurs. Major trauma centers (Royal Melbourne Hospital, Alfred Hospital in Victoria; Royal Adelaide Hospital in South Australia; Royal Perth Hospital in Western Australia) have 24/7 availability of orthopedic and vascular surgery, which is essential given the proximity of the femoral vessels during this approach. Regional trauma centers may have limited after-hours vascular capability, so procedures with high risk of vascular complications should be scheduled during daytime hours when full teams are available. Antibiotic prophylaxis follows the Australian Therapeutic Guidelines (eTG), with cefazolin 2g IV at induction as first-line prophylaxis. For patients with penicillin allergy, vancomycin 25-30 mg/kg IV (maximum 2g) infused over 60-90 minutes is recommended. MRSA colonization requires vancomycin plus gentamicin 4-7 mg/kg IV (maximum 560mg). Medicare Benefits Schedule rebates are available for femoral shaft fracture fixation, nonunion treatment, and tumor excision procedures performed via the anteromedial approach. For patients in regional and remote areas, the Patient Assisted Travel Scheme (PATS) provides financial assistance for travel and accommodation when accessing specialist medical services not available locally. Australian injury epidemiology data suggests that femoral shaft fractures occur at a rate of approximately 10-15 per 100,000 population annually, with bimodal distribution affecting young males in high-energy trauma and elderly females with osteoporosis. The anteromedial approach is particularly relevant in the management of elderly periprosthetic fractures, where MIPO techniques preserve biology and minimize surgical trauma in patients with multiple comorbidities. The Royal Flying Doctor Service (RFDS) and state-based ambulance services provide aeromedical retrieval for time-critical transfers to appropriate facilities for patients in regional or remote areas requiring specialized orthopedic and vascular surgical expertise.

Femur - Anteromedial Approach

Femur - Anteromedial Approach