RESULTS OF SURGICAL TREATMENT OF UNCOMPLICATED SUBAXIAL INJURIES USING CORPECTOMY AND TELESCOPIC PROSTHESES: A RETROSPECTIVE COHORT STUDY Byvaltsev V.A., Sorokovikov V.A., Kalinin A.A., Aliev M.A.
Irkutsk State Medical University,
Railway Clinical Hospital at Irkutsk-Passazhirskiy Station,
Irkutsk Research Center of Surgery and Traumatology,
Irkutsk State Medical Academy of Postgraduate Education – the branch of Russian Medical Academy of Continuous Professional Education, Irkutsk, Russia
The cervical spine (CS) is the most common location of spinal injuries [1]. Tetraplegia and disability are severe complications of subaxial injuries, which require for timely diagnosis and treatment [2]. The main objectives of specialized care for such cases are efficient decompression of neural structures, recovery of spinal stability, and appropriate neurological and social rehabilitation [3].
The anatomical and subaxial injuries are cervical injuries in C3-C7 segments; more than 55 % of them are located at the level of C5, C6 and C7 vertebrae [4]. The main causes of such injuries are road traffic accidents, extreme sports, and falling from height [2]. 2-6 % of patients with blunt spinal injuries have cervical spine injuries, with 10-25 % of clinical worsening in long term period [5]. It was found that annual CS injuries are registered in 64 patients per 100,000 of population, with 55 % of such injuries in combination with the spinal cord injury [6]. The risk of subaxial fractures is high among men, and the mortality reaches 20 % at older and senile age [7].
The conservative management of uncomplicated injuries to the lower cervical spine can cause the posttraumatic instability of cervical segments and chronic pain due to decreasing height of injured vertebrae, progressing deformation, and decreasing sizes of foraminal passages [3, 8]. The aim of surgical interventions for patients with traumatic subaxial injuries after verification of orthopedic instability is decompression of vascular and neural structures with fixation of spinal segments for prevention of deformation and secondary liquor-dynamic disturbances [9, 10, 11].
There are not any uniform surgical approach and techniques for stabilization of injured CS vertebrae. Ventral decompessive stabilizing interventions are less traumatic, and they promote the direct visualization of anterior surface of neural structures, and are considered as surgery of choice in most cases. However, the decrease in quality of formation of the bone block was noted in multi-level manipulations [9]. Dorsal fixation in patients with CS injuries is associated with significant dissection of paravertebral tissues and with quite high risk of postsurgical infectious complications in contrast to the anterior approach. It causes the high amount of poor clinical results in the long term postsurgical period [8].
All above-mentioned facts indicate the insufficient state of knowledge and high social importance of the problem of surgical management that determined the objectives and the tasks of this study.
Objective – to analyze the results of surgical treatment of uncomplicated subaxial injuries using corpectomy and telescopic prostheses.
MATERIALS AND METHODS
Study design
The retrospective cohort multi-center study was conducted.
Acceptance criteria
Inclusion criteria:
1) unstable lower cervical spine injuries (5 or more criteria of White and Panjabi modified scale);
2) injury severity of E degree (ASIA/ISCSI);
3) a single injury to the subaxial cervical spine – A2 type according to AO Spine [10];
4) absence of neurovisualizational signs of traumatic changes in the spinal cord;
4) admission < 48 hours from the injury moment.
Exclusion criteria:
1) a subaxial injury as result of osteoporosis; severity A3, B and C according to AO Spine;
2) complicated spinal injury;
3) subacute or long term period after CS injury;
4) presence of concurrent disease at the stage of decompensation.
Realization conditions
Surgical interventions were conducted in the Neurosurgery Center of Irkutsk Railway Clinical Hospital.
All patients (n = 75) were operated by the single surgical team. The left-sided retropharyngeal approach by Cloward was used. The Caspar retractor (Germany) was used. The optical magnification was performed with Pentero 900 (Zeiss, Germany). The intrasurgical fluoroscopic control was realized with the electronic optical converter (Siemens, Germany). The staged resection of adjacent intervertebral disks, removal of vertebral body and decompression of vascular and neural formations were conducted. The telescopic prosthesis ADD-plus (Urlich, Germany) was implanted, and screw fixation to adjacent vertebrae with in situ distraction were performed.
Study duration
The study group was estimated for clinical neurological and radiological values before the surgery at the moment of discharge, and after 12, 24 and 36 months from the surgery moment. The minimal follow-up was 3 years, the maximal one – 5.9 years.
Study results
Main result
Efficient fixation of the operated level, and recovery of spatial relationships in the cervical spine were achieved after ventral decompression and placement of the telescopic prosthesis.
Additional results
The gender and constitutional features (gender, age, body mass index) of the patients, the parameters of surgical interventions, the postsurgical course (surgery duration, blood loss, activation time, hospital stay), the clinical data (pain intensity in the cervical spine according to VAS, satisfaction with surgery according to Macnab score), results of instrumental methods, and presence of complications were investigated.
Statistical analysis
The statistical findings were received with Microsoft Excel and Statistica 8. Non-parametrical tests were used for analysis of significance of differences. P value < 0.05 was considered as the lower border of confidence. The information is presented as the median and the interquartile range as Me (25-75 %).
The study was conducted in compliance with the standards of Good Clinical Practice, and the principles of Helsinki Declare of the World Medical Association. The study protocol was approved by the ethical committees of all participating clinical centers. The article does not contain any restricted data. The patients gave the informed consent before participation in the study.
RESULTS
The table 1 shows the general data on patients who were included into the study. The analysis showed the prevailing cohort of men of mean age.
Table 1
The distribution of the studied patients by sex, age and constitutional features
|
Criteria |
Study group (n = 75) |
|
Age (years) |
32.5 (28; 56) |
|
Female gender (n, %) |
32 (42.7 %) |
|
BMI (kg/m2) |
24.7 (22.2; 26.9) |
The table 2 shows the parameters of surgical interventions, and the data of postsurgical period. The removal of one vertebral body was realized in 59 (78.7 %) cases, two bodies – in 14 cases (18.7 %), three adjacent vertebral bodies – in 2 (2.6 %).
Table 2
Characteristics of surgical interventions and specificity of the postoperative period of patients of the studied group
|
Criteria |
Study group (n = 75) |
|
Operation time (min) |
160 (120; 205) |
|
Blood loss (ml) |
180 (140; 235) |
|
Activation time (days) |
2 (1; 2) |
|
Terms of hospitalization (days) |
12 (10; 13) |
The catamnesis showed a significant decrease in intensity of pain in the cervical spine from 76 mm (69; 89) to 12.5 mm (6; 24) in the early postsurgical period (p = 0.0007), and to 8.5 mm (5; 17) in the long term period (p = 0.01) (Fig. 1).
Figure 1
Dynamics of the level of pain syndrome on VAS in the cervical spine in patients of the study group
36 months after the surgery, the patients’ satisfaction according to Macnab score: excellent outcomes – 45 (60 %); good – 27 (37 %); satisfactory – 3 (4 %); poor results – 0 cases.
The fully functional bone block was identified in 12 months in 61 (81.3 %) cases, after 24 months – in 67 (89.3 %), after 36 months – in 71 (94. %) cases.
The retrospective analysis identified some various perisurgical complications (the table 3). Microsurgical suturing of a defect was carried out for intrasurgical injury to dura mater. In case of registration of intermuscular hematoma, it was drained. Prolonged antibacterial therapy was carried out for contamination of the surgical wound. The unfavorable consequences identified in catamnesis were the causes for revision decompressive stabilizing interventions.
Table 3
Characteristics of registered complications in the studied group of patients
|
Criteria |
Study group (n = 75) |
|
Intraoperative complications, n,% |
1 (1.3 %) |
|
Dural tears |
1 |
|
Nerve root injury |
- |
|
Early postoperative complications, n, % |
5 (6.7 %) |
|
Formation of hematoma |
3 |
|
Surgical site infections |
2 |
|
Late postoperative complications, n, % |
6 (8 %) |
|
Degeneration of level adjacent to surgery |
2 |
|
Pseudarthrosis |
3 |
|
Instability of fixing structures |
1 |
The figures 2-5 show a clinical case of surgical management of a patient with uncomplicated injury to C7 vertebra (A2 type according to AO Spine) operated with corpectomy and the body-replacing prosthesis.
Figure 2
Cervical spondylography before surgery: a) direct projection; damaged vertebra (CVI) indicated by an arrow; b) lateral projection; damaged vertebra (CVI) indicated by an arrow
Figure 3
MRI of the cervical spine prior to surgery: a) sagittal projection, the yellow line indicates the level of axial sections
Figure 4
Cervical spondylography 6 months after corpectomy and delivery of the implant at the level of CVI: a) direct projection; b) lateral projection
Figure 5
MRI of the cervical spine 6 months after surgery: a) sagittal projection, the yellow line indicates the level of slices; b, c) axial sections at the level of intervertebral disks adjacent to the CVI body
DISCUSSION
Surgical management of patients with subaxial injury is non-unique, particularly, in terms of selection of a surgical approach [12]. In 1982, Allen and Ferguson [13] offered a classification of subaxial injures with six categories in dependence on an injury mechanism according to radiologic data, but without priority of a surgical technique. In 2007, Vaccaro et al. created SLIC (Subaxial cervical spine injury classification system) [14] for selection of management techniques by means of calculation of points according to three criteria (injury mechanism, presence of an injury to the disk-ligament complex, neurological status), which present the main and independent determinants for prediction and treatment of patients.
Cervical corpectomy is a universal procedure for ventral decompression of the spinal cord [15]. Reconstruction of the anterior column with removal of the vertebral body is a necessary condition for restoration of the height of an injured level and sagittal profile of CS [12].
In 2007, based on the systematic review of subaxial injuries to CS, Elder et al. developed an algorithm for selection of a surgical approach [16]. Selection of a surgical technique for such patient was based on presence of an injury to the anterior supporting column and on need for visualization of neural structures [17].
Yokota et al. [18] studied a possibility for conservative management of CS injuries. For the period from 9 months to 9.5 years, 13 patients were examined who received the immobilization with rigid collar. During follow-up, all cases showed the positive time course with disappearance of neurological symptoms. Moreover, the late period showed an increase in local kyphotic deformation. According to the authors’ opinion, besides injury severity, such factors influence on kyphosis progression: young age, injury to both end plates, and destruction of the posterior supporting complex.
In 2019, a metaanalysis was published, where Wengel [19] et al. showed a relationship between modern surgical decompression of the spinal channel and neurological outcomes. Regression of clinical symptoms was noted after early decompression in 422 patients among 1,058 ones with complete spinal cord injuries. The improvement in neurological status by 2 degrees and more (according to ASIA) was 22.6 % as compared to 10.4 % in the group of late decompression. Conversely, the comparison of groups with early and late decompression in patients with incomplete spinal cord injuries did not find any significant differences in degree of clinical improvement.
Khorasanizadeh M. [11] et al. conducted a metaanalysis and identified a relationship between neurological improvement and a degree of an injury to the supporting columns, injury level and its mechanism, and management techniques. An improvement in ASIA by at least 1 degree was in 19.3 % of patients with A type of severity, in 73.8 % – with degree B, in 87.3 % – with degree C, in 46.5 % – with degree D. Moreover, the authors indicate that complete regression of neurological symptoms is not common for degrees A and B, and it was observed in 9.2 % in the group C, and in 46.5 % in the group D.
Our study analyzed only patients with uncomplicated unstable A2 subaxial fractures. The main aims of surgery were restoration of the sagittal profile of CS, prevention of kyphotic deformation and of development of neurological symptoms.
Amer M. et al. published the data on surgical management of 20 patients with subaxial injuries [15]. The authors performed corpectomy from the anterior approach and installed PEEK prostheses. 80 % of cases showed the clinical improvement in mJOA score. Interbody fusion was achieved in all cases. Jain V. et al. [3] observed the course of the postsurgical period in patients with two-level corpectomy of the cervical spine and with stabilization using Mesh-cage and the anterior plate. Spondylodesis was achieved in 91.3 % of cases. Pseudoarthrosis was verified in 8.69 %.
A study by Belirgen et al. [20] showed that the anterior approach (in comparison with the posterior one) caused lower values of intrasurgical blood loss, better ASIA, and recovery of spatial relationships in CS.
The potential complications of ventral interventions include neurological disorders, vascular injuries, esophagus injuries, infections of surgical site, and intermuscular hematomas [11]. Tasiou et al. [1] conducted a retrospective case-control study and reported on 15 (13.1 %) cases with poor outcomes in 114 patients with surgery from the anterior approach. All cases were distributed into early and late. The early complications included dysphagia, liquorrhea, soft tissue edema, intermuscular hematoma (each complication in 1.75 % of cases); clinical worsening, recurrent laryngeal nerve injury, esophagus perforation, superficial wound infection (each in 0.88 %). The long term postsurgical period included degeneration, adjacent segment lesion (2.63 %); tracheoesophageal fistula, implant malposition (each in 0.88 %).
Cervical Spine Research Society presented the data on 5,356 patients with the most common spine abnormalities. The rate of complications after use of the anterior approach was 0.64 %, after posterior one – 2.18 % [21]. Moreover, Aarabi et al. reported that a degree of ventral compression confirmed by postsurgical MRI highly influenced on the long term functional outcome [22].
Telescopic constructs are widely used for CS prosthetics after corpectomy. These implants are uniform and can be extended in situ within the bone defect, recovering the required configuration of CS [15]. The complications of their use include fractures of adjacent vertebrae, and technical difficulties when installing the prostheses [13]. Some authors report on fine results of spondylodesis formation in 93-100 % when using the telescopic implants, as well as ADD-plus [20, 22].
The selection of the vertebral body-replacing prosthesis in decompressive stabilizing surgery is determined by both indications for surgical intervention, and also by material resources in a medical facility and preferences by a surgeon. A construct type and functional capabilities are determined individually in dependence on primary goals [18, 20].
Currently, the telescopic implants can be considered as the most perfect and efficient for anterior approaches. When estimating such constructs, one should estimate the ability to change their vertical size. But from other side, distraction of endoscopic prostheses is associated with “the filling defect”, which may prevent the appropriate spondylodesis in the postsurgical period [17].
After review of some articles by other authors, we did not find any principal differences between anterior decompression and implantation of telescopic prostheses in uncomplicated subaxial injuries (the table 4). We found improvement in long term postsurgical period with high incidence of interbody bone block with low risk of perisurgical complications.
Table 4
Comparative results of using anterior corpectomy and body replacement
|
Author, year |
Number of patients |
Type of construction used |
Evaluation of clinical outcomes |
ormation of bone block in long term period,% |
Complications,% |
Terms of observation |
|
Aarabi B. [5] |
55
|
Ti-cage
|
After surgery, ASIA/AIS degree A in 33 patients (60 %), B – in 22 (40 %) |
58.6 % |
- |
24.2 ± 8 days (median – 19.1 (3.3-127.5) days) |
|
Yoon J.W. [45]
|
1 |
ADDplus ™ (Ulrich Medical, Ulm, Germany) |
No neurologic deficiency after 1 year |
100 % |
0 % |
12 months |
|
Miao D. [35] |
52 |
Ti-cage |
Average increase in values by one degree according to ASIA |
100 % |
- |
49.2 (36; 72) months |
|
Dhillon C.H. [16] |
11 |
Autobone, anterior plate |
Significant improvement in VAS in cervical spine (ð < 0.05) |
100 % |
45 % |
12 months |
|
McGuire D.T. [42] |
30 |
Autobone, anterior plate |
- |
90 % |
10 % |
3.8 months |
|
Burkett C.J. [13] |
29 |
ADD (Ulrich Medical, Ulm, Germany) |
Significant decrease in pain in CS according to VAS |
100 % |
3.4 % |
9.5 (3-24) months |
|
Kasimatis G. [29]
|
74 |
Autobone – 65, Harms-cage (DePuy AcroMed, Rainham, USA) – 6, Pyramesh-cage (Medtronic Sofamor Danek, Memphism USA) – 3 |
ASIA E-23, no changes in polytrauma; improvement in partial injury
|
90.5 % |
12.1 % |
76.8 months |
|
Amer M. [9]
|
20 |
PEEK-cage or body-replacing cage filled with autobone |
mJOA before surgery – 10.3, after 12 months – 12.1
|
80 % - |
15 % |
12 months |
|
Our data |
75 |
ADD-plus (Urlich, Germany) |
Changes in VAS – from 76 mm (69; 89) to 8.5 mm (5; 17), proportion of good and fine results – 97 % according to Macnab |
94.7 % |
16 % |
36 months |
CONCLUSION
The retrospective study confirmed the high clinical efficiency of the anterior decompression and implantation of the telescopic prosthesis for treatment of patients with uncomplicated subaxial injuries. Moreover, the high values of bone block formation were found along with the low rate of symptomatic perisurgical complications.
Information on financing and conflict of interests
The study was conducted without sponsorship. The authors declare the absence of any clear or potential conflicts of interests relating to publication of this article.