MODEL RELEASED. Carpal tunnel syndrome surgery. Image 4 of 13. Surgeon drilling into the wrist of a carpal tunnel syndrome (CTS) patient during surgery to immobilise the joint. CTS is a painful condition caused by the compression of the median nerve in the wrist. It is not known exactly what causes the condition, although repetitive movements and stress are often blamed. Sometimes it can be treated with steroids or physiotherapy, but in severe cases the wrist is immobilised surgically with metal pins. For a sequence of images showing this surgical procedure, see M551/437-M551/449.