Knee – Medial Parapatellar Approach

Modern Study Review (AI-Generated)

High-Yield Summary

The medial parapatellar approach remains the gold standard for wide exposure of the knee joint, particularly in total knee arthroplasty (TKA) and complex intra-articular procedures. It offers excellent visualization of joint surfaces and safe patellar eversion. Although minimally invasive and subvastus approaches are gaining traction for select cases, this approach continues to be the workhorse for most open knee surgeries due to its reliability and extensile potential.

Applied Anatomy & Intervals

Internervous Interval

• None: This approach is a midline or paramedian arthrotomy that splits the quadriceps tendon and medial parapatellar retinaculum without a true internervous plane.

Anatomic Landmarks

• Patella (central reference)
• Tibial tubercle (distal landmark)
• Medial border of the patella and patellar tendon
• Quadriceps tendon proximally

Patient Positioning & Setup

• Table Type: Standard operating table with capability for knee flexion.
• Patient Position: Supine with the knee flexed to 90° during exposure.
• Specialized Equipment:
• Pneumatic tourniquet on proximal thigh for bloodless field.
• Leg holder or bump under the knee to maintain flexion.
• C-arm positioned laterally if intraoperative imaging is required.

Surgical Technique (The “Vital Steps”)

Incision & Superficial Dissection

• Vertical midline skin incision centered over the patella, extending from distal quadriceps tendon proximally to just medial to the tibial tubercle distally.
• Incise subcutaneous tissue and raise a small medial skin flap to expose the medial parapatellar retinaculum.

Deep Dissection & Exposure

• Incise the joint capsule along the medial parapatellar retinaculum, from quadriceps tendon proximally to medial tibial tubercle distally.
• Identify and protect the anterior horn of the medial meniscus at the joint line if not performing TKA.
• Laterally dislocate and evert the patella to fully expose the joint.
• Maintain knee flexion at 90° to optimize visualization and access.

The “Danger Zone”

Post-Operative Pearl

Early controlled range of motion is encouraged, but avoid aggressive knee flexion or forceful patellar mobilization in the first 2 weeks to protect the healing extensor mechanism and medial retinaculum.

Classic Clinical Notes

Knee – Medial Parapatellar Approach

• Position: Supine & tourniquet
• Incision: Vertical, midline, centered over patella to just medial to tibial tubercle
• Internervous plane: None
• Dissection:
• Incise subcutaneous tissue to expose parapatellar retinaculum
• Raise small medial flap of skin & subcutaneous tissue
• Incise joint capsule extending from quadriceps tendon to medial parapatellar retinaculum to medial to tibial tubercle
• If not doing TKA, beware of anterior horn of medial meniscus at joint line
• Dislocate patella laterally & evert
• Flex knee to 90 degrees
• Joint fully exposed
• Dangers:
• Infrapatellar branch of saphenous nerve – usually cut during this exposure; risk of neuroma
• Patellar tendon – problem if it avulses from tibia

Last Updated on January 25, 2026 by orthonet