Total Knee Arthroplasty (TKA) is a common surgical procedure performed to alleviate pain and improve functionality in patients suffering from knee osteoarthritis, particularly in the elderly population. With increasing age, patients often present with a variety of comorbid conditions, one of which is degenerative spine disease (DSD). This condition can lead to anatomical changes and challenges in achieving optimal spinal anesthesia for procedures such as TKA.

Spinal anesthesia, specifically subarachnoid block (SAB), is a widely utilized technique for TKA due to its advantages of reliable muscle relaxation, effective analgesia, and reduced systemic complications compared to general anesthesia. However, elderly patients with DSD present a unique challenge due to altered spinal anatomy, such as narrowed intervertebral spaces and osteophyte formation, which may complicate needle placement for the block. In such cases, the choice of approach for SAB becomes critical to minimize complications and ensure a successful block.