Tommy John Surgery: Reconstructing Elbow Stability
Tommy John surgery, formally known as ulnar collateral ligament (UCL) reconstruction, repairs a torn or damaged UCL. This ligament, located on the inner side of the elbow, connects the upper arm bone (humerus) to one of the forearm bones (ulna), providing crucial stability to the joint. UCL injuries commonly affect athletes, particularly those involved in overhead throwing sports like baseball, due to the repetitive stress placed on the elbow. The primary goal of this surgery is to restore the elbow’s stability, reduce pain, and enable individuals to return to their previous level of function.
The Primary Tendon Choice: Palmaris Longus
The palmaris longus tendon is frequently chosen for UCL reconstruction when a patient’s own tissue, an autograft, is used. This tendon is located in the forearm. Its popularity stems from its expendability; its removal typically does not impair hand or wrist function, as it is a minor wrist flexor and many people can lack it without functional deficit. The palmaris longus is present in approximately 80% to 90% of the population, though its absence can vary by ethnicity.
This tendon is well-suited for UCL reconstruction because it generally provides adequate length and a suitable diameter to serve as a strong replacement for the damaged ligament. Surgeons often prefer the palmaris longus due to its convenient location and the minimal associated donor site complications. Its consistent characteristics make it a reliable option for creating a stable new ligament structure.
Alternative Tendon Options
When the palmaris longus is absent or deemed unsuitable for reconstruction, surgeons have several alternative tendon options. The gracilis tendon, sourced from the inner thigh as part of the hamstring muscle group, is another common choice. This tendon is often utilized if the palmaris longus is too small, unavailable, or in cases requiring revision surgery, without significantly compromising knee function.
The plantaris tendon, located in the calf, can also serve as a viable autograft. Other less common autograft sources include the semitendinosus (another hamstring tendon), toe extensors, patellar tendons, or portions of the Achilles tendon. In situations where a patient’s own tendons are not viable or preferred, an allograft (cadaveric tissue) may be used. Allografts can help avoid donor site morbidity associated with harvesting a patient’s own tissue and can be a suitable option for various patients, including non-elite athletes.
Key Considerations for Tendon Selection
The selection of a tendon for UCL reconstruction involves several important considerations to ensure a successful outcome. A primary factor is the tendon’s expendability, meaning its removal should not result in significant functional loss or weakness at the donor site. This principle guides the choice of tendons that have redundant functions or are not critical for everyday activities.
Another important aspect is the biomechanical properties of the graft, which must possess sufficient strength and appropriate length to effectively reconstruct the torn ligament and withstand the considerable stresses placed on the elbow. Ease of surgical access for harvesting the tendon and minimizing invasiveness are also practical considerations. Ultimately, the surgeon’s judgment, patient-specific factors such as the presence and quality of potential donor tendons, and any prior surgical history all influence the final tendon selection.