Early decompression of chronic nerve compression can restore blood supply to the nerve Chronic nerve compression is more common in clinical practice, such as carpal tunnel syndrome, elbow tunnel syndrome, and spinal canal compression due to chronic intraspinal stenosis. Prolonged compression can lead to nerve dysfunction, such as loss of motor or sensory function, pain, numbness, and paralysis. The study of pathological changes following nerve compression can inform the choice of treatment. Recent studies have shown that surgical decompression in patients with carpal tunnel syndrome can result in a better clinical prognosis than anti-inflammatory and hormonal injections. It has been suggested that the timing of surgical intervention is also a very important factor in obtaining satisfactory clinical function, and that the earlier the surgery, the better the functional recovery, but there is no high level of research evidence to support this. Recently, an experimental animal study done by James et al. at the University of California found that in an animal model of chronic nerve compression, early surgical decompression can re-establish blood flow to the nerve and improve nerve ischemia, and the relevant findings were published in a recent issue of JBJS. In this study, 10 male, 6-week-old C57BL/6 mice were divided into 6 groups: nerve crush group (10 cases), 2-week (18 cases), 4-week (18 cases), 6-week (18 cases) chronic nerve compression injury group, and 2-week (18 cases), 6-week (18 cases) chronic nerve compression injury decompression group. The chronic nerve compression injury model was fabricated by the method described by Guptan et al. on Muscle nerve, and the successful preparation of the compression injury model was confirmed by neurophysiological means. Sciatic nerve blood flow was measured by laser speckle method, and the levels of hypoxia-inducible factor 1α (HIF1α), catalase, superoxide dismutase (SOD), and matrix metalloproteinases 2,9 (MMPs) were analyzed in different groups of mouse nerve models. It was found that chronic nerve compression injury leads to nerve congestion in the early stages, while a decrease in nerve blood flow signal occurs at 4 weeks. Similarly, hypoxia-inducible factor 1α (HIF1α), catalase, and superoxide dismutase (SOD) levels are progressively elevated after nerve compression, while extracellular matrix-altering proteins are elevated later in the disease. Early decompression restores neural blood flow in a hyperemic state; whereas late decompression does not restore neural blood flow signals due to the fact that MMP9-mediated structural reconstruction of the extracellular matrix of the machine begins to occur at late decompression, and structural changes eventually lead to irreversible neural blood flow impairment. Electromyographic examination of nerve conduction velocities in the test mice revealed that nerve conduction velocities began to normalize 2 weeks after surgical decompression in both early and late decompression; however, only the distal nerve latencies in the early decompression group returned to normal. The investigators concluded from this study that chronic nerve compression injury can lead to a reduction in blood flow to the nerve and alter the underlying structure through upregulation of enzymes such as hypoxia-inducible factor 1α (HIF1α), catalase, superoxide dismutase (SOD), and matrix metalloproteinases 2,9 (MMPs), leading to nerve ischemia. Surgical decompression of early nerve compression can better restore normal electrophysiological function of the nerve than late nerve decompression.