Although a simple radiographic examination cannot confirm stenosis, the short pedicle observed in lateral radiographs, narrow distance between the pedicles observed in the anterior and posterior radiographs, calcified ligaments or intervertebral discs, stenosis of the foramen, and hypertrophy of the facet joint can all be seen. The presence or absence of segmental instability on the flexion–extension lateral image can be used to determine the necessity of fusion. In a dymamogram, a translational motion of more than 4–5 mm or an angular change of more than 10°–15° indicates segmental instability [8,31].

MRI can be used to detect LSS and measure the size of the spinal canal and the degree of degenerative changes [1,23,32-35]. It should be emphasized that the correlation between the severity of morphologically stenotic lesions on an MRI and clinical symptoms is small. In other words, the intensity of clinical symptoms is not directly correlated with the degree of stenosis detected by MRI [32]. Although MRI confirms strictures in a large percentage of asymptomatic patients, it should not be employed for screening. MRI can be used to confirm the diagnosis in patients with persistent neurogenic claudication or radiating pain. A sagittal T1-weighted scan clearly shows the foraminal stenosis, whereas a sagittal T2-weighted image resembles a myelogram [36]. When the fatty tissue that is typically dispersed around the nerve root is absent, foraminal stenosis can be identified. The central stenosis is clearly visible in both the T2- and T1-weighted pictures of the axial cut image. When the adipose tissue that usually covers the disk and nerve root is absent, axial slices on T1-weighted images show a distant lateral disk herniation. Recently, it has been found that LSS may be quantified using intraspinal diffusion tensor imaging metrics as apparent diffusion coefficient and fractional anisotropy [5].

CT images are frequently used for surgery planning in patients with stenosis [37]. Patients with dynamic strictures, postoperative leg discomfort, severe scoliosis or spondylolisthesis, metal implants contraindicating MRI scans, and lower-extremity complaints without aberrant results on MRI scans should also undergo a CT scan in addition to the imaging test. Myelography is the most suitable term. Myelography, however, is an intrusive procedure that increases the risk of headaches, nausea, and seizures. Standing in flexion and extension while having restricted sight on the MRI is required for this test, which records moving pictures from the lateral side [20,33]. In addition, CT can actually provide the information required for decompression surgery because it offers more information about bone architecture, such as osteophytes and disk calcifications, than MRI [35]. Patients with pacemakers who are unable to undergo MRI diagnostic examinations have a great alternative imaging option in CT scan.

Electromyography can be employed in patients with concomitant conditions such as diabetes if the diagnosis of neuropathy is ambiguous [33]. Furthermore, lesions caused by vascular issues in the lower extremities can be ruled out using vascular Doppler imaging. The Bicycle and Bruce technique may be diagnostic, according to one study [33,38].

An intermediate type of treatment between nonsurgical options and epidural steroid injections. According to several studies, between 50% and 87% of patients have short-term (around 3 weeks) symptom alleviation using epidural steroid injection therapy [2,19,41-44]. Epidural steroid injection is indicated for acute radiating pain and nervous claudication that are interfering with daily life despite pain relievers and rest, which are expected to improve symptoms [45]. In addition, research on the use of ropivacaine and dexmedetomidine as well as epidural neuroplasty in conjunction with thoracolumbar surgery has been recently published [46,47]. Epidural neuroplasty is employed to alleviate back discomfort and/or radiating pain caused by mechanical compression of the intravertebral nerve structures or neuroinflammation. Epidural neuroplasty/epidural glue separation has recently gained popularity and has produced encouraging outcomes. Epidural abscesses, irreparable nerve tissue destruction, and cardiovascular events have all been recorded as fatal consequences [24].

After receiving appropriate conservative treatment for at least 2–3 months, surgery is recommended when patients complain of pain, muscle weakness, and gait disturbance caused by lower-extremity paresthesia, which affect their daily life. Surgery is rarely used to treat low back pain caused by spondylolisthesis and scoliosis when there is no instability [48]. It is difficult to predict the likelihood of recovery after surgery, even when uncommon long-term motor paralysis is the main symptom; thus, other causes should be identified prior to surgery. Rapidly developing neurological abnormalities or the lack of urine and feces necessitate early decompression [11,21,46]. When deciding whether to undergo surgery, abnormal findings on CT or MRI imaging should correlate to the patient’s complaints [22]. The principle of surgical treatment is to sufficiently decompress the nervous structures [11]. If instability due to the removal of too many bone structures following adequate decompression is anticipated, immobilization should be considered. Candidates for fusion surgery may also include those who have severe stenotic lesions and spondylolisthesis, scoliosis, or kyphosis [49]. Other fusion requirements include disk herniation following prior surgery, recurring stricture, and proximal segmental degeneration caused by prior fusion. In older individuals with severe multisegmental stenosis, laminectomy alone may be recommended (Figs. 1–3) [3]. Less than 50% of the inner section of each facet of one spinal segment must be removed during decompression to provide appropriate decompression without resulting in segmental instability [3]. More localized decompression is possible by identifying the exact cause of symptoms with selective nerve root blocks. Checking for neural membrane adhesions, which may be present even in the absence of a history of surgery, during decompression can help limit the risk of dural damage [50]. If the stenosis of the lateral depression and neural foramen is severe, the surgical instruments used during decompression may cause nerve damage [51,52]. The sagittal plane must be adjusted for fusion surgery to be successful, and even elderly patients aged over 65 and very senior patients aged over 80 can have successful operations provided the sagittal plane is balanced thereafter. Gained is decrease the chance of falls following surgery [28,29,53,54]. Recently, single- or biport endoscopic surgery and minimally invasive screw insertion techniques guided by fluoroscopy or a navigation system have emerged. With the rapid advancements in surgical techniques and technology, there is a growing trend toward the use of spine endoscopy. Several randomized controlled trials have demonstrated that endoscopic and standard minimally invasive or open techniques produce comparable patient-reported outcomes [50,55,56]. No difference was observed in patient-reported outcomes between a number of additional randomized controlled trials contrasting endoscopic discectomy and laminectomy with conventional procedures, such as microsurgical laminectomy, microdiscectomy, or open discectomy [56]. Similar to arthroscopy employed in knee and shoulder surgery, biportal endoscopy contains two working channels, one for the endoscope and one for the instruments. For the lumbar spine, the posterolateral (or intervertebral) approach and the extraforaminal route (or transforaminal) are the two most often used endoscopic surgical procedures [55,56-58]. Despite the development of numerous novel techniques for lumbar disk herniation treatment, open microdiscectomy and laminotomy/laminectomy remain the current standard of care [8,50]. Global trends in spinal endoscopy utilization, on the other hand, indicate that Asia has the highest utilization and growth. According to a recent global survey, 55% of non-Asian surgeons and 70% of Asian surgeons perform spinal endoscopy [59]. These obstacles must be removed to allow broader access to the entire spine community as the body of scientific literature supporting this treatment grows and its application becomes more advanced and widespread in Asia.