Total Shoulder Arthroplasty (TSA) replaces the damaged surfaces of the ball-and-socket shoulder joint with artificial components, typically metal and plastic implants. TSA is commonly used to treat end-stage arthritis, which causes significant pain and stiffness due to cartilage loss. Biceps Tenodesis (BT) targets the long head of the biceps tendon (LHBT). This procedure involves detaching the tendon from its origin inside the shoulder joint and reattaching it lower down on the humerus (upper arm bone).
Surgical Context: The Biceps Tendon During Total Shoulder Arthroplasty
Biceps tenodesis is not an automatic part of total shoulder arthroplasty, but it is frequently performed as a supplemental procedure. The primary goal of TSA is to replace the damaged humeral head and glenoid socket to restore smooth, pain-free joint movement. The biceps tendon is a separate soft tissue structure that runs through the joint. It can be irritated by the underlying arthritic condition or by the new prosthetic components.
During TSA, the surgeon assesses the condition of the long head of the biceps tendon once the joint is exposed. If the tendon appears compromised, damaged, or unstable, the surgeon may elect to perform a biceps intervention. This decision-making process is highly individualized and often occurs intraoperatively.
The long head of the biceps tendon can interact negatively with the implants, potentially leading to persistent pain after the joint replacement. Performing a tenodesis alongside TSA addresses this secondary pain generator. Managing the biceps tendon when it is pathological may contribute to a better overall outcome.
Specific Pathologies Requiring Biceps Intervention
The need for biceps intervention during TSA is driven by pre-existing or intraoperative findings related to the tendon’s health. One common reason is chronic inflammation, known as bicipital tendinitis, which causes persistent pain localized to the front of the shoulder. This inflammation often results from the same degenerative process that caused the joint arthritis.
Another frequent pathology is severe fraying or degeneration of the tendon tissue, termed tendinosis. This condition weakens the structure and makes it a source of chronic pain. The severity of fraying increases the likelihood that the tendon will continue to cause symptoms if left untreated, making removal of the damaged portion necessary for pain relief.
A third primary indicator for intervention is instability, where the tendon repeatedly subluxates or dislocates out of the bicipital groove. This instability causes a painful snapping or popping sensation with arm movement. Furthermore, a partial tear of the tendon, especially near its anchor point, prompts the surgeon to perform a tenodesis or tenotomy to stabilize the structure and alleviate discomfort.
Tenodesis Versus Tenotomy: Surgical Options
When the biceps tendon is pathological during TSA, the surgeon chooses between tenodesis or tenotomy. Biceps tenodesis involves detaching the painful tendon from its original site and reattaching it to the humerus further down the arm. This reattachment, secured with a fixation device, preserves the length and tension of the muscle-tendon unit.
The goal of tenodesis is to eliminate pain from the compromised segment while maintaining the functional integrity of the biceps muscle. Fixing the tendon below the shoulder minimizes the risk of the muscle belly dropping or bunching up, a cosmetic deformity known as the “Popeye muscle.” This method is favored for younger, more active patients who prioritize strength and cosmesis.
In contrast, biceps tenotomy is a simpler procedure where the surgeon cuts the biceps tendon from its attachment and allows the remaining tendon to retract naturally down the arm. Tenotomy is a less technically demanding and faster surgery, making it a viable option for older patients or those with low-demand lifestyles. While effective at relieving pain, the retraction may result in a noticeable bulge in the upper arm, the “Popeye” sign, in approximately 23% of patients.
Both tenodesis and tenotomy produce similar functional outcomes and pain relief in many patients. However, tenodesis tends to have a lower rate of cosmetic deformity and less risk of post-operative muscle cramping. The choice between the two is a shared decision, weighing factors like age, activity level, cosmetic concerns, and the severity of the tendon pathology.