In outpatient clinics, it is often encountered that patients who have undergone lateral spinal fusion surgery, either due to cervical spondylosis or lumbar spine diseases (including lumbar disc herniation, lumbar spondylolisthesis, lumbar tuberculosis or lumbar spinal stenosis), or more often, spinal deformities (including various scoliosis, kyphosis, ankylosing spondylitis, traumatic kyphosis, etc.), experience pain again after a period of time, and after proper rest After appropriate rest, no relief is seen. What are the possibilities at this point? Is there a fracture of the internal fixation, or is it something else? The most common problem in this case is poor fusion and pseudarthrosis. The following is an explanation of pseudoarthrosis. Causes The spine is made up of different vertebrae connected by an intervertebral disc in the front and two small joints in the back, just like a strap. These joints allow the spine to bend and twist. As we age or experience trauma, these joints also often wear out or degenerate and eventually become painful. If physical therapy, exercise and medication do not control the pain, your doctor may recommend fusion surgery to stabilize the arthritic area of the spine. Once a patient has decided to undergo spinal fusion surgery, obtaining a strong fusion becomes the next step, and the word Pseudoarthrosis comes from the Greek word meaning pseudarthrosis, which often means that the surgery did not result in a strong fusion. Selecting the right patient for surgery and using better surgical techniques can significantly reduce the occurrence of pseudoarthrosis after spinal fusion surgery. Many patient factors contribute to the increased risk of pseudarthrosis: smoking (nicotine), obesity, osteoporosis, long-term use of steroid medications, diabetes, other chronic diseases, previous pseudarthrosis, malnutrition, etc. Other important factors that can reduce surgical failure are related to the surgical technique, such as autologous bone graft (autograft, either from the spine itself or from the hip (iliac crest). The use of modern internal fixation instruments, such as traction hooks, arch nails, cages, rods and wires, can be used to properly align and stabilize surgically fused segments. Even for the best surgeons, the minimum rate of risk of forming a pseudarthrosis is 5-15%. Symptoms: Physicians have a number of difficulties in making a definitive diagnosis of the presence of a pseudarthrosis. If a pseudarthrosis is present, localized pain very similar to that before the surgery will be present and will worsen over several months, or will become progressively worse in the short term after surgery. Imaging: If internal fixation was used for spine surgery, x-rays will show a loose or broken internal fixation as in Figure 1. The best test to determine a pseudoarthrosis is a CT axial or plain scan. Treatment options: If the diagnosis of a pain-causing prosthetic joint is made, your spine surgeon will recommend further treatment, including surgery.