With the rapid development of transportation industry, the incidence of traumatic spinal cord injury (SCI) has been increasing year by year, and the incidence of SCI in the United States is 28-55 per million people, with about 10,000 new cases per year, and the incidence of young patients is the highest, and the prognosis of neurological function after acute SCI is still very unsatisfactory. U.S. statistics show that the cost of SCI treatment directly for the whole U.S. in 1995 was as high as $7.7 billion, and the actual situation in China may exceed that of the U.S. in terms of population proportion, although no exact relevant statistics are available. Acute SCI imposes a heavy economic and psychological burden on the whole society, families and individuals, and therefore the whole society is eager to cure SCI completely. numerous studies have shown that SCI can be divided into primary and secondary damage according to the pathological evolution. Studies have shown that prevention and reversal of secondary SCI is important for maximizing residual spinal cord function and promoting structural and functional reconstruction of the injured spinal cord, and is one of the main means of treating SCI at present. Currently, there is no specific drug that can effectively prevent and reverse secondary SCI and promote neurological recovery, therefore, surgical intervention is widely used in North America for the clinical treatment of acute SCI. However, due to the lack of rigorously designed and executed randomized controlled clinical studies, there is still a great controversy on the definition of the time window for surgical treatment, the choice of surgical procedure, and the efficacy of surgery to promote neurological recovery. This paper presents a review of the research progress on the impact of the choice of surgical intervention on the prognosis of acute spinal cord injury. Yang Min, Department of Orthopedic Trauma Surgery, Yiji Mountain Hospital, Wanan Medical College 1. The influence of the choice of the time of surgical intervention on the prognosis of acute spinal cord injury in animals Studies have shown that the time-responsive edema after SCI is a vasogenic edema caused by the loss of endothelial cell integrity and increased vascular permeability due to trauma, and because the dura mater of the spinal cord is relatively fixed and not easy to expand, the intramedullary edema spreads to the adjacent segments of the injury and is accompanied by Intramedullary pressure increases. Twenty-four to 48 hours after severe SCI, there was necrosis at the site of injury, especially significant hemorrhage in the central gray matter region of the spinal cord. A few days later, a cavity forms in the hemorrhagic area, and there is diffuse necrosis in the cephalocaudal 2 cm of the spinal cord centered on the injury, usually with more distinct necrotic boundaries. This gradual evolution of cavity and necrosis formation in the injury area and adjacent parts of the injury is often accompanied by characteristic pathological changes such as infarction, which is known as post-traumatic infarction. The alteration of spinal cord blood flow after SCI is an important cause of spinal cord necrosis and loss of neurological function, as well as an important cause of secondary spinal cord injury. In addition to spinal cord ischemia, which leads to electrolyte disturbance, post-traumatic inflammatory response and apoptosis, the injury is aggravated by Dimar et al. 1999, who demonstrated experimentally that early spinal cord decompression can effectively alleviate and reverse secondary spinal cord injury. They replicated a rat model of thoracic spinal cord impact injury, followed by epidural placement of a compression device to cause continuous compression of the thoracic spinal cord, followed by decompression at 0, 2, 6, 24 and 72 hours post-injury. Shields et al. replicated moderate spinal cord injury at the T10 level in rats and caused 38% and 43% spinal canal stenosis to simulate clinical spinal canal stenosis caused by spinal fracture dislocation. The results showed that rats that underwent early surgical decompression at 6 or 12 hours post-injury had better ability to support their body weight than rats that delayed decompression until 24 hours post-injury. The postoperative pathomorphology showed that early surgical decompression after spinal cord injury had a protective effect on the spinal cord axons of rats, which could reduce the area of spinal cord injury and promote the functional recovery of the hind limbs of rats. Based on the above analysis, most scholars believe that the prognosis of neurological function of the body after acute SCI is closely related to the following three factors: 1) the degree of instantaneous primary injury; 2) the degree of spinal cord compression due to spinal fracture dislocation or hematoma; and 3) the duration of spinal cord compression. In terms of current clinical treatment, there is a consensus that spine surgeons usually use interventional treatments for spinal cord decompression of the injured segment, repositioning of fracture dislocations, and stabilization and fusion of the spine in order to alleviate or relieve the latter two factors that contribute to spinal cord injury exacerbation. Although experimental animal studies have shown that early spinal cord decompression within hours after spinal cord injury provides maximum relief and reversal of secondary spinal cord injury for optimal neurological recovery, there is still considerable debate among spine surgeons about the optimal timing of interventional surgical treatment after SCI, focusing on the definition of the time window for early surgical treatment and whether early surgery increases the risk of SCI patients’ complications and deterioration of neurological function. A multicenter prospective study by Marshal clearly did not support early interventional surgery for acute SCI: in this study, 26 patients who underwent surgery within 5 days after the injury had a history of spinal cord injury. In this study, four of the 26 patients who underwent surgery within 5 days of injury experienced neurological deterioration, whereas none of the 44 patients who underwent surgery after 5 days experienced neurological deterioration. The authors concluded that early surgery is not advisable especially for patients with cervical SCI. However, at the same time, 10 of the 149 patients awaiting surgery or receiving surgical treatment also experienced deterioration of neurological function, the incidence of which was close to that of patients receiving early surgical treatment. Thus, Wang Yansong et al. analyzed Marshall’s study without sufficient data to show the relationship between the choice of timing of surgical treatment and deterioration of neurological function. In contrast, the deterioration of neurological function that occurs in conservatively treated patients is more likely to be due to instability of the spinal injury segment and has no clear relationship with the choice of timing of surgery. With further research into the mechanism of secondary SCI, investigators have proposed two golden windows of clinical treatment based on a nationwide randomized controlled clinical trial protocol for acute spinal cord injury: that is, high-dose methylprednisolone shock therapy given within 8 hours of acute SCI achieves some efficacy, while high-dose methylprednisolone shock therapy given within 3 hours of injury achieves better efficacy. These studies clearly suggest that the treatment of acute SCI should target the mechanism of secondary spinal cord injury, and the choice of the time window for interventional treatment is particularly important in the clinical treatment of acute SCI. In terms of clinical practice, the feasibility of interventional line surgery within 3-8 hours after acute SCI is low in most patients due to factors such as emergency care, resuscitation, transport, imaging, and preparation for surgery after cervical spine trauma.Ng equals 26 patients with traumatic C3-T1 spinal canal encroachment of 25% or more in eight spine surgery centers in North America from 1996 to 1997 within 8 hours after injury Decompression therapy was performed: 1) traction alone; 2) traction plus surgery; and 3) surgery alone. The results showed that less than 10% of the patients meeting these criteria had cervical spine trauma at the eight spine surgery centers mentioned above during the same period, while only two patients were able to undergo surgical decompression within 8 hours of injury, and seven patients underwent surgical decompression within 12 hours of injury. The results of this prospective, nonrandomized controlled study suggest that early post-injury surgical decompression did not increase the incidence of surgery-related complications, and the authors concluded that delayed transport and imaging were the main reasons why most patients were not able to undergo surgical decompression within 8 hours and recommended that new procedures be redesigned so that more patients could receive surgical decompression within 8 hours of injury. pointillart et al. in another prospective, non-randomized controlled study investigating 49 patients with SCI undergoing surgical decompression fixation within 8 hours of injury. The authors found that patients operated within 8 hours of injury did not have better neurological recovery than those operated within 8-24 hours of injury or without surgery, concluding that the prognosis for neurological function after SCI is primarily related to the degree of initial spinal cord injury. However, the authors did not clarify the number of patients who completed surgical decompression within 8 hours, and the small number of patients enrolled in the surgical group may also be an important factor in the determination of efficacy. in a prospective, non-randomized controlled study of 91 patients with cervical spinal cord injury, Papadopoulos et al. found that 34 patients who underwent emergency MRI-guided surgical decompression within 12.6 hours post-injury There was satisfactory recovery of neurological function and no significant emergency surgical complications. The authors counted 39 satisfactory neurological recoveries among the 66 patients who underwent surgery overall (including some with complete SCI), whereas only 6 of 25 patients in the non-surgical group had neurological improvement, but the authors did not compare the difference in neurological recovery between patients who underwent surgical decompression within 12.6 hours of emergency and those who underwent surgical decompression thereafter, possibly related to the small number of patients in this group. To establish the feasibility of determining the relationship between the timing of surgical decompression after SCI and neurological recovery through a standard large-scale randomized controlled, prospective clinical study, Tator et al. conducted a retrospective clinical survey: the authors’ retrospective clinical case data came from 36 spine surgery centers in North America, and 585 patients met the inclusion criteria between 1994 and 1995, which represents only 50 percent of the patients admitted to the same centers during the same period. The other 50% were not enrolled because of late admission, age, open injury, and lack of spinal cord compression. Of these patients, 65% underwent surgical decompression: 23.5% within 24 hours of injury; 15.8% 25-48 hours after injury; 19% 48-96 hours after injury; and 41.7% after 5 days. The authors concluded that there is no clear evidence that the surgical treatment described above promotes neurological recovery, and there is considerable controversy over whether early surgery reduces the length of hospital stay and the occurrence of complications such as pneumonia and deep vein thrombosis. Although surgical decompression is more commonly used by physicians in North America to treat acute spinal cord injuries, there is no consensus among clinical treatment centers on the choice of the point of post-injury interventional surgical treatment. Based on the statistical data that only a small number of patients receive surgical treatment within 24 hours, the authors concluded that if a large randomized controlled, prospective clinical study is needed to determine the optimal time window for post-injury treatment, more extensive public education on field first aid and specific training for emergency department physicians is necessary to allow more patients to be brought to the hospital for treatment within the shortest possible time after injury. Based on these findings, Rosa et al. further defined spinal cord decompression surgery within 24 hours of injury as the early surgical treatment group and surgery beyond 24 hours as the late surgical treatment group. The authors retrospectively reviewed the clinical research literature published from 1996-2000 and analyzed the clinical data of 1687 patients who underwent early surgical decompression, late surgical decompression, and non-surgical treatment, respectively, showing that early interventional surgical decompression, repositioning, and stabilization of the spine within 24 hours after acute SCI was consistent, at least in terms of safety, with delayed surgery after 24 hours post-injury, but that those who received Patients treated with acute surgery within 24 hours had a higher neurological recovery. However, the authors further concluded by analysis of homogeneity that only patients with incomplete SCI who underwent early surgical decompression achieved better clinical outcomes (89.7%). The authors acknowledged that early surgical decompression for acute spinal cord injury is a practical treatment option, but numerous different variables have been identified in clinical case studies that affect the final outcome of neurological recovery; therefore, conducting prospective, randomized controlled clinical studies as soon as possible is the best way to determine the time point for interventional surgical decompression. For example, in a study by Tuil et al [20], it was found that a higher percentage of patients with an ASIA-graded cervical SCI up to grade A with concurrent hypotension and bradycardia received surgical decompression treatment at a mean of 80.9 hours post-injury, whereas patients with the same level of injury without concurrent hypotension and bradycardia received surgery at a mean of 58 hours. These variables are all factors that influence the determination of the time to surgery and can likewise have an impact on the prognosis of neurological function. Most clinical investigators have limited the time to early surgical decompression to within 72 hours after injury and late surgery to beyond 72 hours after injury based on the above reasons. mirza et al. retrospectively reported that 15 of 30 patients with cervical SCI underwent surgical decompression within 3 days after injury and the remaining 15 underwent surgical decompression after 3 days. The authors observed that early surgical treatment within 3 days promoted recovery of neurological function and did not increase the incidence of complications, while shortening the length of hospital stay. In contrast, Sapkas et al [22] retrospectively analyzed the data of a group of 31 patients who underwent surgical decompression and fixation within 72 hours of injury and 36 patients who underwent surgical treatment after 72 hours of injury, and they concluded that there was no difference in the overall neurological prognosis between early and late surgical treatment. Only patients with an initial incomplete cervical spinal cord injury have the potential for postoperative neurological recovery, and early surgery may be more beneficial for patients with incomplete spinal cord injuries. In addition, early surgery for cervical SCI is safe and does not demonstrate postoperative neurological deterioration. The authors acknowledge that defining 72 hours post-injury as early may in fact not be the optimal time window for early interventional surgical treatment and that further prospective randomized controlled studies are needed. The data show that a clinical study by Vaccaro et al. on the prognostic impact of early or late surgical decompression on neurological function in a group of patients with cervical SCI is the only prospective, randomized, controlled study available. The authors treated 34 patients with early surgical decompression within 72 hours of injury and 38 patients with surgery 5 days after injury, and the results of their clinical data showed no difference between the early and late surgical treatment groups in terms of neurological recovery and length of hospital stay. However, it is worth noting that a total of 20 patients in this group were lost to follow-up, so further clinical investigation is needed for its conclusion. Numerous domestic scholars have also done a series of useful studies on the correlation between the timing of surgical interventions and neurological prognosis after acute cervical spinal cord injury, and it is generally believed that surgical interventions for acute cervical SCI should be performed as early as possible within 3 days after injury in the hope of obtaining better neurological recovery. Duh et al. studied the neurological recovery of patients with early (within 25 hours) and late (more than 200 hours) surgery and conservative treatment after SCI by post-hoc analysis of clinical data from the Second National SCI Treatment Study, and concluded that both early and late surgery promoted neurological recovery, with no significant difference between the two. The authors’ analysis suggests that the two surgical time windows of 25 hours and more than 200 hours after injury may have avoided the post-traumatic period of spinal cord edema and therefore the deterioration of neurological function due to surgery. It is worth noting that this clinical study was a randomized, double-blind controlled study of the efficacy of two drugs for spinal cord injury, so the selection of patients for surgery time did not allow for randomized grouping, and the authors are aware that the conclusions of this study require further clinical prospective, randomized controlled studies. 3, the impact of the choice of surgical intervention on the complications and length of hospital stay in patients with clinical acute spinal cord injury Because SCI, especially high cervical SCI, is often accompanied by cardiopulmonary impairment, some scholars believe that early surgical treatment may increase the complications of spinal cord injury in these patients, and the surgical risk is great, which is one of the controversial points affecting the choice of surgical intervention. However, with the rapid improvement in modern spinal surgery techniques and surgeon confidence, critical care and neuroanesthesia, there is little difference in the surgical complications associated with early surgical treatment of acute spinal cord injury compared to non-surgical treatment. Waters et al. conducted a prospective study of 2204 patients with spinal cord injury and found no difference in complication rates between the surgical and non-surgical treatment groups. Mckinley et al. concluded that although early surgery within 72 hours of injury did not promote better neurological recovery, it did shorten the length of hospital stay and reduce respiratory complications such as pneumonia and atelectasis. Therefore, most of the current literature suggests that surgery within 3 days after injury is safe for spinal cord injury. 4. Problems with clinical studies Fehlings et al. divided the results of clinical studies into three categories: Class I is a well-designed study protocol that can be strictly implemented in a clinical randomized controlled trial; Class II is a prospective non-randomized controlled study; and Class III is a retrospective study or case report and expert review. Fehlings et al. recently conducted a systematic review of the published literature on the effects of decompression on neurological recovery after SCI over the past 10 years, and especially over the past 5 years. It was found that of all 66 publications, none of them were Class I clinical studies, all of them were Class II and III clinical studies. Among them, there was only one study that could do randomized controlled grouping, and the rest of the clinical studies could not do randomized controlled grouping. On the basis of this study, Fehlings et al. concluded that the relationship between the timing of acute SCI decompression and the prognosis of neurological recovery is still inconclusive in the current clinical research. To address this clinical challenge, their research center at the University of Toronto, in conjunction with several other spine institutes, initiated a multicenter (a single research unit does not have sufficient clinical cases to further subdivide patients into more subgroups for controlled studies), prospective clinical trial study to evaluate surgical decompression within 24 hours (early) and after 24 hours (late) after acute spinal cord injury. surgical decompression on the prognosis of cervical SCI. This study requires good collaboration between spinal surgeons and imaging physicians and a high level of emergency critical care, which the authors believe is available in the multicenter study described above. However, the authors analyzed the randomized controlled grouping of patients in this study due to a number of factors such as ethics and technicalities that limited the study. For example, the ethics are such that a physician would not assign a patient with deteriorating neurological function to the late surgery group in clinical care; and the technicalities of emergency care and imaging limit the number of patients who can arrive at the spine surgery center to be treated within 24 hours. in their study, Mckinley et al [9] noted the following characteristics in the composition of patients in the early surgery group within 72 hours: mostly high-energy car accident injuries and a high prevalence of female patients. The authors concluded that high-energy crash injuries, unlike fall injuries and medically induced spinal cord injuries, are associated with vertebral fractures and instability and therefore require early surgery. Patients who underwent surgery after 72 hours post-injury had incomplete spinal cord injuries. These clinical study data reflect the difficulty of randomized grouping in clinical treatment from one side. Therefore, the authors suggest that the lack of difference in neurological recovery between the early and late surgical and non-surgical treatment groups in this study may be due to the different neurological status of the patients at the time of initial grouping. 5. Conclusion Although numerous animal studies have shown that early surgical decompression after spinal cord injury can alleviate and reverse secondary spinal cord injury, there is still no clinical conclusion as to whether there is a similar window of treatment for surgical decompression as in animal studies. In other words, clinicians have not yet reached a uniform understanding of the role of surgery in the treatment of acute SCI and the timing of surgery. From a large number of Class II clinical studies, the preliminary guidelines are: early surgical decompression within 72 hours is safe and effective for hemodynamically stable patients; emergency surgical decompression should be recommended for patients with progressive deterioration of neurological function after SCI. And from the data of a large number of Class III clinical studies, the preliminary proposed alternative is that surgical decompression for acute cervical SCI is a practical treatment, as long as the patient does not have life-threatening multisystem trauma, and surgical decompression treatment within 24 hours after injury is possible, which also reduces the incidence of post-traumatic complications and shortens the length of hospital stay. In conclusion, for SCI, a difficult-to-treat worldwide medical problem, a global multicenter systematic collaborative large sample clinical case analysis discussion is one of the ways to solve this problem.