A bursa is a small, fluid-filled sac found throughout the body, positioned where soft tissues like tendons move over bony prominences. Its primary purpose is to act as a cushion and gliding surface, reducing friction. When a bursa becomes inflamed, a condition called bursitis occurs, causing pain and swelling. If conservative care fails, the bursa may be surgically removed in a procedure called a bursectomy. This intervention often raises the question of whether the body can regrow this cushioning structure after it has been excised.
Function of the Bursa
The bursa provides a smooth, frictionless interface that facilitates comfortable movement. Each bursa is lined with a synovial membrane that secretes viscous, lubricating synovial fluid into the sac. Bursae are categorized as constant (always present) or adventitial (forming in response to chronic friction or pressure). The most commonly affected bursae are near major joints like the shoulder, elbow, hip, and knee, such as the subacromial bursa or the olecranon bursa. Bursitis typically results from repetitive overuse, direct trauma, or underlying conditions like gout or rheumatoid arthritis. The inflamed sac thickens and produces excessive fluid, creating pressure and localized pain with movement.
Regeneration Following Bursectomy
The direct answer is yes; a bursa possesses the biological capacity to regenerate following surgical removal. While bursectomy excises the inflamed bursa, it is often impractical to remove every synovial cell lining the sac. These residual synovial cells or surrounding connective tissues retain the potential to form a new, functional fluid-filled sac, sometimes referred to as a neobursa.
This regenerative process is a natural response to persistent mechanical stressors in the area. If a bony prominence remains subject to high friction, the body attempts to recreate the protective layer. The mechanism involves the organization of mesenchymal cells and the secretion of synovial fluid, effectively creating a new sac to minimize tissue damage. The formation of a neobursa is thus a sign that the body is trying to restore friction reduction.
Recurrence and Inflammation
It is important to distinguish bursa regeneration from the clinical problem of symptomatic recurrence. The new bursa (neobursa) only becomes a medical issue if it becomes inflamed, leading to recurrent bursitis. This inflammation happens when the underlying cause that triggered the original bursitis has not been successfully eliminated.
For instance, if a person undergoes bursectomy for prepatellar bursitis (“housemaid’s knee”) but continues to kneel frequently without protective padding, the neobursa is highly susceptible to inflammation. Systemic conditions like gout or rheumatoid arthritis must be managed effectively to prevent recurrence. Studies examining open bursectomy, particularly for the olecranon bursa, have reported recurrence rates as high as 22% in some patient groups. This rate underscores that surgery addresses the symptom (the inflamed sac) but not the root cause (the biomechanical or systemic irritant).
To prevent a regenerated bursa from becoming symptomatic, the treatment focus shifts to addressing the source of irritation. This may involve activity modification, using protective gear like pads, correcting biomechanical issues, or ensuring complete medical management of underlying inflammatory diseases. The failure to resolve the chronic irritation is the primary factor leading to the return of painful symptoms, not simply the fact that the bursa itself has regrown. Effective long-term relief depends on changing the environment that caused the bursa to become inflamed.