Total Knee Arthroplasty (TKA), or total knee replacement, is a successful orthopedic procedure performed to alleviate chronic pain and restore function in a joint damaged by arthritis. The surgery involves resurfacing the ends of the femur and tibia, and often the back of the kneecap, with metal and plastic components. While the focus is on replacing the joint surfaces, patients frequently inquire about the fate of surrounding soft tissues, specifically the bursa, a small, fluid-filled sac near the joint.
Understanding the Knee Bursa and Total Knee Replacement
A bursa is a thin, slippery, sac-like structure containing synovial fluid, located between bones and soft tissues like tendons, muscles, and skin. Its purpose is to cushion and protect the joint, reducing friction during movement. Several bursae exist around the knee, but the prepatellar bursa, located in front of the kneecap (patella) and under the skin, is most often associated with inflammation.
The goal of a total knee replacement is to remove damaged cartilage and bone surfaces, creating a new, artificial joint. This process addresses the structural integrity and alignment of the joint. TKA focuses on bone and cartilage replacement, not soft-tissue removal. Since the bursa lies outside the knee joint capsule, the standard surgical approach does not require its removal.
The Surgical Protocol for Soft Tissue
In the majority of standard TKA procedures, the bursa is intentionally preserved and remains in place. Surgeons aim to be minimally invasive with surrounding healthy soft tissues to promote faster recovery and reduce the risk of complications. Since the prepatellar bursa is a separate structure outside the main joint, it is generally left intact during the bone-cutting and implant-placement phases.
However, a bursectomy, or surgical removal of the bursa, becomes necessary in specific, non-routine scenarios. The main reason for removal is if the bursa is diseased, most commonly due to chronic or septic (infected) bursitis that has not resolved with conservative treatments. An inflamed or thickened bursa can interfere with the surgical field, making the placement of prosthetic components difficult or potentially contaminating the sterile implant site.
The decision to remove the bursa is based on the condition of the soft tissue encountered during the operation. If a massive bursa is present, a surgeon may choose to remove it simultaneously with the knee replacement. However, a staged approach—removing the bursa first and allowing the wound to heal before performing the TKA—is sometimes preferred to minimize the risk of infection. Removing the sac in cases of chronic, non-infected bursitis prevents the issue from persisting after the joint replacement.
Post-Operative Swelling and Bursa Management
Significant swelling is an expected part of the body’s healing response after a total knee replacement, affecting the entire knee area. This generalized swelling can sometimes be mistaken for post-operative bursitis. The swelling often peaks within the first few days and gradually subsides over the following weeks and months as the body recovers from surgery.
In some instances, the remaining bursa tissue may become irritated or inflamed due to surgical manipulation or post-operative friction, leading to post-operative bursitis. This potential complication is not common, and it can occur in bursae other than the prepatellar one, such as the pes anserine bursa. Post-operative bursitis is managed non-surgically, often with rest, ice application, and elevation, which are components of the standard recovery protocol.
To manage expected post-operative swelling and reduce irritation to remaining soft tissue structures, cryotherapy (ice) is recommended multiple times daily in the immediate recovery period. Elevation of the surgical leg above heart level assists in minimizing fluid accumulation. These actions help control inflammation and discomfort, supporting the overall recovery of the knee and surrounding soft tissues.