A partial medial meniscectomy is a surgical procedure treating an injury within the knee joint. The meniscus is a crescent-shaped piece of fibrocartilage between the thigh bone and the shin bone, acting as a shock absorber and load distributor. A meniscectomy is the general term for surgically removing damaged meniscal tissue to relieve pain and restore normal knee function. This procedure addresses damage to the medial meniscus, the cartilage on the inner side of the knee, by removing only the torn portion.
Understanding the Medial Meniscus and Injury
The medial meniscus is a C-shaped band of cartilage in the inner compartment of the knee. It decreases stress on the joint by distributing compressive forces over a wider area. It is less mobile than the lateral meniscus because it is firmly attached to the tibial collateral ligament, making it more susceptible to injury when the knee is twisted.
The meniscus’s outer third, the “red zone,” has a limited blood supply, while the inner two-thirds, the “white zone,” has virtually none. This lack of blood flow limits the tissue’s ability to self-heal.
Tears requiring a partial meniscectomy usually occur in the avascular white zone or are complex and non-repairable, such as radial, flap, or degenerative tears. A radial tear disrupts the tissue’s ability to distribute forces, while a flap tear creates a loose piece of cartilage that can mechanically interfere with joint movement. The goal is to remove the unstable tissue causing pain and locking sensations, preserving as much healthy tissue as possible for natural shock absorption.
The Partial Meniscectomy Procedure
The partial meniscectomy is performed using an arthroscopic technique, a minimally invasive approach. The surgeon makes two or three small incisions, known as portals, around the knee joint. An arthroscope, a thin tube containing a camera and light source, is inserted through one portal to provide a magnified view of the knee’s interior on a monitor.
Specialized surgical instruments are inserted through the other portals. The surgeon probes the medial meniscus to confirm the tear pattern and instability of the damaged segment. The “partial” nature means the surgeon carefully trims and shaves away only the torn, frayed, or unstable tissue using instruments like meniscal biters and arthroscopic shavers.
The objective is to create a stable, smooth rim of healthy meniscus, removing the source of mechanical symptoms like catching or locking. This maximizes preserved tissue, differing from a meniscal repair (suturing torn tissue) or a total meniscectomy (removing the entire meniscus).
Immediate Post-Surgical Recovery
The first one to two weeks focus on controlling swelling, managing pain, and protecting the small incisions following the outpatient arthroscopic procedure. Patients should apply ice to the knee for 15 to 20 minutes several times a day and keep the leg elevated to minimize swelling. Prescription pain medication is used for acute pain, which lasts only a few days.
Weight-bearing is progressive, and immediate weight-bearing is often allowed as tolerated, using crutches for support and balance. Patients are instructed on simple home exercises, such as quadriceps sets and heel slides, to maintain muscle activation and restore early range of motion. Stitches or surgical tape strips are typically removed at the first post-operative visit, around seven to ten days after surgery.
Rehabilitation and Long-Term Outlook
Formal physical therapy (PT) typically begins within the first week after surgery. Initial goals are to regain full knee range of motion and prevent muscle atrophy in the quadriceps and hamstring muscles. Strengthening exercises progress from simple straight leg raises and quad sets to advanced resistance training, balance work, and functional activities.
The timeline for returning to activities depends on individual progress and the extent of tissue removed. Most people resume daily activities and light exercise, like walking or cycling, within four to eight weeks. Returning to high-impact sports or heavy labor requires a longer rehabilitation period, often taking several months. The procedure has a favorable short-term prognosis, with many patients reporting good results.
However, removing meniscal tissue alters knee joint mechanics, increasing stress on the articular cartilage. This biomechanical change carries a long-term risk of developing knee osteoarthritis, a degenerative condition. Maintaining quadriceps and hamstring strength through continued exercise is important to mitigate this risk and preserve joint stability.