**Abstract**

Knee surgeries are the most commonly performed joint surgeries in the modern world, which help maintain the quality of life by improving joint functions. These include open trauma, sports injury, or joint replacement surgeries. Among various available regional analgesia options for knee surgeries, the goal is to choose motorsparing, opioid-sparing, and procedure-specific modalities. Therefore, it is essential to know the complex anatomy of the knee joint, essential steps of various surgical procedures, and innervations of the pain-generating structures for a particular surgery. Background knowledge of all these essentials helps select the most appropriate regional analgesia technique for knee surgeries.

**Keywords:** Knee joint analgesia, Total knee replacement, Total knee arthroplasty, Procedure-specific anesthesia, Motor sparing analgesia, Opioid sparing analgesia, Subsartorial blocks

#### **1. Introduction**

The knee is the biggest and the most complicated joint of the human body. Being a most stressed joint subject to enormous pressure while providing flexible movement, it is vulnerable to injury. During walking and jumping, it is loaded with 7-fold body weight. The attached muscles and ligaments provide stability and flexibility to the knee joint. The most important structure of the knee joint is its cartilage surface which might get damaged due to trauma, overload, and genetic disorders. As a result, the patient experiences pain, inflammation, and a limitation of the range of motion, finally leading to an impaired gait.

Knee surgeries are one of the most commonly performed, life-changing surgical procedures of the modern world, leading to improved health-related quality of life and functional status [1, 2]. Knee surgeries vary from minimally-invasive arthroscopic procedures (in relatively younger populations) to open arthroplasty procedures (in the elderly populations).

Before deciding the analgesia techniques for the postoperative period, knowledge of functional anatomy, surgical steps, pain generation, pain generators, and innervation of the pain generators is essential. A multidisciplinary approach with multimodal analgesia is the demand of time for successful surgical outcomes. Regional analgesia (RA) is an important component of multimodal analgesia to deal with perioperative pain. Among many available RA options, challenges include

selecting more procedure-specific, motor-sparing, and opioid-sparing options suitable for enhanced recovery after surgeries (ERAS) protocols. A properly planned procedure-specific RA technique provides optimal analgesia without any motor effects, which helps in early mobilization and discharge, reducing opioid consumption and their side effects significantly.
