The Biomechanical Stability Study Of Fixation And Traction On Skull Of The Mayfield Head Holder And The Clinical Application In Cervical Spine Surgery In Prone Position

Objectives: To study the relationship between the compression or tensile load on patient's head in the surgery and the pressure in fixation or the position of the skull pins on patient's head, so as to provide evidence for the clinical use of the Mayfield head holder. To summarize the present clinical application of the Mayfield head holder, the standard install and uninstall approach of the holder on human's head, the benefit and possible problems owing to the Mayfield head holder and ways to avoid the problems.Method: Measure the compression or tensile load of standard and non-standard pin position or pressure of fixation, study the statistics and the graph of the load and relative displacement, therefore analyze the relationship of the pressure and the position or the load of fixation and the suggestion of the pin position and pressure. Analyze 66 cases of patients who had cervical spine surgery in the prone position. Record the documents of the surgery and relief degree of symptoms and complications. Study the biomechanical features of the holder applying on the head by imitating the compression or tensile load on patient's head in the surgery and the pre-surgery reposition on the cadaver.Results: According to the statistics of the tests, in the compression tests, it gets the results of p>0.05 comparing standard and non-standard position and load. In the tensile tests, there is significant difference between standard and non-standard position (p<0.05) while there is no significant difference among non-standard positions and between standard and non-standard load (p>0.05). In 66 cases of patients, the benefits of applying the Mayfield head holder is significant, there were three cases that had minor complications and only one possibly related to the holder. The Mayfield head holder benefits surgeries in its solid fixation, adjustability, tensile function, convenience in anesthesia regulation, avoidance of injuries in the face and eyes, and pre-surgery reposition. Meanwhile it may cause problems as bleeding and inflammation, dislocation of the pin and scalp laceration, blood pressure and heart rate increase, air embolism, and other rare complications like epidural hematoma, meningitis, cerebrospinal fluid fistula, etc. The Mayfield head holder provides much more convenience than problems in surgeries , and the complications happen very rare and can be avoided to a great extend by standard approach.Conclusions: In the clinical use of the holder, it is recommended that the load of the skull pin should be 60 lbs to ensure secure fixation and avoid complications. And the pin position should be 2.5cm above the auricle and can move appropriately higher to get better effect in pre-surgery reposition while not influence the biomechanical features of the Mayfield head holder system. The Mayfield head holder is safe and secure, and provides the cervical spine surgeries with lots of convenience. It is suggested that it should be applied more in the cervical spine surgeries in the country.