Hip - Anterior Approach

Modern Study Review (AI-Generated)

High-Yield Summary

The Smith-Peterson anterior approach to the hip is a classic internervous and intermuscular approach primarily used for hip arthroplasty, fracture fixation, and select hip exposures. It utilizes the interval between the sartorius (femoral nerve) and tensor fascia lata (superior gluteal nerve), minimizing muscle damage and preserving function. This approach remains a gold standard for direct anterior hip access and has been refined with minimally invasive, muscle-sparing techniques in contemporary practice.

Applied Anatomy & Intervals

Internervous Interval

Between Sartorius (Femoral nerve) and Tensor Fascia Lata (Superior gluteal nerve)
Deeper exposure involves the interval between Rectus Femoris (Femoral nerve) and Gluteus Medius (Superior gluteal nerve)

Anatomic Landmarks

Anterior Superior Iliac Spine (ASIS)
Anterior half of the iliac crest
Lateral aspect of the patella (for distal incision extension)

Patient Positioning & Setup

Table Type

Standard operating table with radiolucent capabilities preferred

Patient Position

Supine, with optional sandbag under the ipsilateral hip to facilitate exposure

Specialized Equipment

Limb positioners or bumpers to allow controlled external rotation and adduction of the leg
C-arm positioned for intraoperative fluoroscopy as needed

Surgical Technique (The “Vital Steps”)

Incision & Superficial Dissection

Longitudinal or slightly curved incision from the anterior half of the iliac crest to the ASIS, extending distally 8–10 cm toward the lateral patella
Identify and protect the lateral femoral cutaneous nerve (LFCN) as it pierces the fascia near the interval between sartorius and TFL

Deep Dissection & Exposure

Externally rotate the leg to relax the sartorius muscle
Identify the interval between sartorius and TFL approximately 2–3 cm distal to the ASIS
Incise the deep fascia on the medial side of the TFL
Detach the origin of the TFL to develop the plane safely
Identify and protect the ascending branch of the lateral femoral circumflex artery crossing between sartorius and TFL
Detach the rectus femoris origin from the AIIS and superior acetabular rim for capsular exposure
Adduct and externally rotate the leg to tension the hip capsule
Incise the capsule longitudinally or in a T-shaped fashion for joint access

The “Danger Zone”

Structure	Location & Risk	Protection Strategy
Lateral Femoral Cutaneous Nerve (LFCN)	Pierces fascia ~2.5 cm distal to ASIS near interval between sartorius & TFL	Identify early; avoid deep fascia incision too medially
Femoral Nerve	Lies anterior to hip joint in femoral triangle, medial to rectus femoris	Stay lateral and superficial during dissection; avoid deep medial dissection
Ascending Branch of Lateral Femoral Circumflex Artery	Crosses between sartorius and TFL proximally	Identify and ligate or cauterize carefully to avoid bleeding

Post-Operative Pearl

Early mobilization is encouraged with hip precautions focusing on avoiding excessive extension and external rotation to protect the anterior capsule repair. Weight-bearing status depends on the underlying pathology and fixation stability.

Classic Clinical Notes