Adult degenerative scoliosis (ADS) is a spinal deformity that occurs after bone maturity. ADS is a spinal deformity with Cobb angle > 10° on coronal plane due to asymmetric degeneration of articular disc and facet joint.[1] The main symptoms of ADS include back pain, nerve root pain, intermittent claudication and spinal deformity. The incidence of ADS increases with age.[2, 3] With the aging of China's population and increasing expectations for motor function, it has become one of the most significant spinal diseases.[4, 5]
Although the number of operations for ADS has gradually increased, the indications and the most appropriate treatment are still controversial.[6] Bridwell pointed out that deformities are the biggest concern for young people, while disability and pain is the most concerned among older patients.[6] For patients with ADS, the primary goal of surgery is to reduce pain and improve quality of life, the second is to achieve satisfactory deformity correction, mainly in the sagittal plane, decompression of nerve structure, prediction of neurological dysfunction and solid fusion can reduce the incidence of mechanical failure and reoperation.[7] Two aspects must be carefully considered when planning long segmental surgery. The first is to identify symptomatic segments and their extent, that is, segmental deformities that must be treated to relieve symptoms and prevent rapid progression. Secondly, to determine the relationship between the symptomatic segments, the top of the vertebral body and the overall balance of the spine, and to determine the superior instrument vertebral body (UIV), the amount of osteotomy and the degree of spinal and pelvic internal fixation, in order to restore the normal alignment of the spine, improve the fusion rate of bone graft, and prevent the failure of internal fixation and related problems of adjacent segments after operation.
Good systematic treatment usually has good treatment guidance for disease classification. [8–12] At present, the most commonly used classification for the clinical treatment of ADS is Lenke-Silva classification, [13] [14] but we believe that this classification focuses more on the correction of scoliosis, for us, we prefer to solve the patient 's symptoms, and correction is of minor importance. Berjano proposed a classification to guide ADS treatment according to the relationship between degenerative responsible segments and apical vertebrae.[15] Berjano type I: when the responsibility segment does not involve the apical vertebra region and there is no obvious sagittal plane imbalance, only the responsibility segment is fused, Berjano type Ⅱ: when the responsibility segment involves the apical vertebra region, the apical vertebra region is fused, Berjano III: when the responsible segment includes the apical and non-apical regions, the fusion body bends or extends to the adjacent segments, Berjano IV: spinal unbalance, sagittal deformity to be corrected > 25% with mild or severe coronal imbalance. The main point of this classification is to identify the responsible segment causing symptoms, the degenerated segment adjacent to the fusion range, and then guide the surgical strategy, which is more in line with our treatment concept. So in this study, we retrospectively analyzed the selection of short-segment fusion and long-segment fusion based on Berjano classification. The data of the whole course of treatment were collected, and the postoperative recovery and satisfaction of the patients were investigated.
Inclusion criteria
The study reviewed 92 patients (36 males and 44 females) who underwent spinal surgery for ADS in our hospital from January 2016 to January 2020. Adult scoliosis defined as coronal Cobb angle greater than 10° showed nerve root compression and intermittent claudication, and Meet the four treatment criteria of Berjano classification. The exclusion criteria were as follows: (I) patients with ADS secondary to lumbar fracture, tumor, ankylosing spondylitis or leg length ; (II) who had undergone any surgical treatment at the symptomatic segment (drug injection, minimally invasive decompression or laminectomy) ; (III) ADS patients who had modern compensatory postures due to radicular pain or acute back pain (which could lead to false imaging parameters).
Operative procedures
We choose the mode of operation according to Berjano classification[15], Berjano type I and II were short fusion segment group, Berjano III and IV were long fusion segment group.
Before operation, the symptomatic segments and their range of activity were determined according to the imaging examination or EMG data of the patients. The principle of treatment is to improve the symptoms, control the development of the deformity, and correct the deformity if necessary. For patients with many complications and poor physical conditions, short segmental decompression/fusion is the only choice. As a result, the patient was placed in a prone position for surgery. After disinfection and towel laying, the muscle tissue was peeled off layer by layer according to the preoperative positioning incision, bilateral laminae were exposed, pedicle screws were placed, spinal canal decompression, intervertebral exploration, nucleus pulposus removal, interbody fusion cage fixation and fusion were performed, according to the preoperative design, titanium rod and spinal fusion correct curvature, and the spine is properly corrected.
Evaluation Indices and follow-up
Posterior lumbar decompression and fusion was performed by two same spinal surgeons. The operative time, blood loss, segment of fusion decompression and fixation, blood transfusion and other intraoperative data were recorded. Patients completed the assessment questionnaire with the assistance of residents during preoperative and postoperative follow-up, including Bone pain Visual Analog scale score (VAS), Oswestry Disability Index (ODI) and Lumbar stiffness Disability Index (LSDI), as well as a survey of efficacy satisfaction (Specifically how well the respective surgical treatment solved the patient's problem, there are five answer categories: great help, help, help a little, no help, aggravation).
X-ray films of full-length standing spine were recorded and measured before operation and during the follow-up period of 3, 6 and 18 months after operation. Coronal Cobb's Angle, Lumbar Lordosis angle (LL), Sagittal Balance angle (SVA), Pelvic tilt (PT), Sacral slope (SS), spine and pelvis matching value PI-LL were measured. The average follow-up time was 3 years.
Statistical analysis
SPSS version 25 (IBM,Armonk,NY,USA) is used for data entry and statistical analysis. The measured data were expressed by mean and standard deviation. Independent sample t-test was used for comparison between the two groups, and paired sample t-test was used for intra-group comparison. The counting variables are expressed by frequency and percentage (%), and the Fisher exact probability method is used for inter-group comparison. P < 0.05 indicated that there were statistically significant differences in all analyses.