Research Progress on the Posterior Midline Lumbar Spinous Process‐Splitting Approach

ABSTRACT

The traditional posterior median approach laminectomy is widely used for lumbar decompression. However, the bilateral dissection of paraspinal muscles during this procedure often leads to postoperative muscle atrophy, chronic low back pain, and other complications. The posterior midline spinous process‐splitting approach (SPSA) offers a significant advantage over the traditional approach by minimizing damage to the paraspinal muscles. SPSA reduces the incidence of muscle atrophy and chronic low back pain while maintaining the integrity of the posterior spinal structures. The technique involves longitudinal splitting of the spinous process, which allows for adequate access to the lamina for decompression without detaching the paraspinal muscles. As a result, it provides a clearer surgical field and facilitates muscle preservation, which reduces the risk of postoperative complications. Additionally, SPSA requires only standard surgical instruments, making it accessible in most surgical settings. This paper reviews the anatomical considerations, surgical techniques, and clinical applications of the SPSA, highlighting its effectiveness in reducing muscle atrophy and improving recovery outcomes. The paper also discusses its potential in treating conditions such as lumbar spinal stenosis, disc herniation, and spondylolisthesis. Furthermore, it emphasizes the need for future research to establish the long‐term benefits of SPSA and refine surgical techniques. The results suggest that SPSA is a promising alternative to traditional approaches, with better outcomes in terms of muscle preservation and overall recovery.

The lumbar spinous process‐splitting approach primarily involves three methods of splitting the spinous process: (A and B) Classic spinous process‐splitting technique: The spinous process is longitudinally split along the midline, with the base detached from the lamina to preserve the bilateral attachment of the paraspinal muscles. Bilateral decompression is achieved, providing access to both sides of the spinal canal and minimizing muscle disruption. (C) Half‐splitting technique: The spinous process is split longitudinally from the midline, with the decompression‐side half fractured and detached from the lamina. (D) Bilateral decompression via unilateral laminectomy. (E) Modified Marmot technique: The spinous process is longitudinally split from the midline and tilted outward while remaining attached to the lamina. (F) Ventral portions of the lamina and ligamentum flavum are resected to create sufficient space between the remaining lamina and dura mater, facilitating decompression.

1. Introduction

Lumbar spinal stenosis (LSS) and other degenerative lumbar conditions are common clinical entities, often presenting with lower back and leg pain, neurogenic claudication, and reduced mobility, with incidence increasing with age [1, 2, 3, 4]. For individuals unresponsive to non‐surgical treatment options, decompressive laminectomy via a posterior midline approach is the preferred treatment [5, 6]. The traditional midline approach involves detaching the paraspinal muscles bilaterally from the laminae and spinous processes, along with resecting the spinous processes and associated ligaments. However, the detachment and retraction of these muscles during surgery can result in ischemic injury, increasing the risk of postoperative dysfunction, muscle atrophy, chronic low back pain, or failed back surgery syndrome [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. To minimize paraspinal muscle damage from the traditional midline approach, various minimally invasive techniques have been introduced, such as spinous process osteotomy [19, 20], unilateral approach for bilateral decompression [15, 21, 22], minimally invasive decompression using tubular retractors [23, 24], and muscle‐sparing interlaminar decompression [25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37].

In 2005, Watanabe et al. [30] first reported the posterior midline spinous process‐splitting approach (SPSA) for isolated decompression in LSS. This technique involves longitudinally splitting the spinous process to access laminectomy and decompression while preserving the paraspinal muscles attached to either side of the spinous process. Follow‐up magnetic resonance imaging (MRI) at 2 years postoperatively revealed a paraspinal muscle atrophy rate of only 5.3%, significantly lower than the 23.9% observed with the traditional open approach, thus minimizing iatrogenic paraspinal muscle injury and avoiding resection of the posterior column ligamentous–muscular complex.

2. Materials and Methods

Publications related to lumbar SPSA were identified using PubMed, Web of Science, and Google Scholar. The keywords “lumbar spine,” “decompression,” “posterior midline approach,” and “spinous process‐splitting” were selected to search the literature from January 1990 to September 2024 based on titles and abstracts.

Inclusion criteria were as follows: (1) Studies involving the surgical procedure via SPSA; (2) original research articles, systematic reviews, and meta‐analyses; (3) studies reporting clinical outcomes, radiological outcomes, or technological advancements. The exclusion criteria included articles without full text, non‐English articles, and case reports.

Quality assessment: an initial total of 5264 relevant articles were retrieved. Collectors conducted a preliminary screening by reviewing the titles and abstracts to evaluate the validity and relevance of each article, excluding duplicates and non‐relevant studies. Ultimately, 59 English‐language articles met the inclusion criteria for this review, consisting of 5 randomized controlled trials, 33 retrospective studies, 16 prospective studies, 3 technical reports, and 2 types of review literature (1 meta‐analysis and 1 systematic review). For studies that were not randomized controlled trials, the quality evaluation was conducted using established criteria tailored to non‐randomized studies. This included assessing whether the study had an adequate sample size to ensure statistical power and the ability to detect clinically relevant differences. Additionally, the statistical methods used to analyze the data were reviewed, ensuring that appropriate tests were applied and results were correctly interpreted. The articles were sourced from reputable academic databases, including PubMed, Web of Science, and Google Scholar (Figure 1).

FIGURE 1.

Literature screening flowchart.

3. Anatomical Considerations of the SPSA for Lumbar Surgery

The paraspinal muscles are a core component of the axial and dorsal muscle groups, playing a crucial role in supporting, stabilizing, and facilitating spinal motion. The paraspinal muscle group consists of the iliopsoas, quadratus lumborum, and erector spinae, which includes the longissimus, iliocostalis, and the deep transversospinalis muscles, notably the multifidus and rotatores. The multifidus, one of the largest and most medial of the deep paraspinal muscles, is innervated by the medial branch of the dorsal rami and is significantly impacted during posterior midline surgical approaches.

Aylott et al. [38] analyzed computer tomography (CT) data of the lumbar spine from 200 patients using Osirix software to study the dimensions and variations in lumbar spinous processes. They observed that the highest and widest spinous processes occurred at L1, L2, and L3, while the smallest was at L5. Male spinous processes were, on average, 2–3 mm higher and 1 mm wider than female spinous processes across all lumbar levels. The dimensions of the lumbar spinous processes change with age, with notable increases in height and width, the latter showing a more significant increase over time. Lin et al. [39] conducted a retrospective analysis of anatomical parameters in 120 patients and found that the greatest spinous process height, length, and cortical thickness were observed at the L3 level, while the largest vertebral width was noted at S1. Additionally, significant differences were observed between sexes, with males exhibiting greater spinous process height, length, and interspinous distance compared to females. Leng et al. [40] found the spinous process length increased from L1 and peaked at L3, after which it gradually decreased, with the minimum length observed at L5. The maximum width was recorded at L3 and the minimum at L5. The greatest tip thickness was observed at L1, while L3 had the thinnest tip. Conversely, the thickest central portion was found at L5, with the thinnest at L2. Lastly, the base thickness was greatest at L2 and least at L1. Ayvaz et al. [41] reported similar findings in their study, further corroborating these results. Sobottke et al. [42] analyzed lumbar CT data from 565 patients and reported an average spinous process thickness of 2.5 ± 0.5 mm, with a decreasing trend from anterior to posterior, and notable variations across different lumbar levels. Overall, the L2 and L3 spinous processes were significantly thicker than the other lumbar levels, while the L5 spinous process was the thinnest, smallest in volume, and shortest in height.

Xu et al. [43] evaluated the visibility angle and surgical corridor in nine fresh adult cadaver specimens (including 45 lumbar vertebrae) by simulating surgery and performing anatomical measurements under different retraction widths (8, 10, and 12 mm). By measuring the fracture widths of 45 lumbar segments, the study determined that a safe margin for retraction ranges from 10 to 12 mm, ensuring that all surgical procedures can be performed smoothly via SPSA.

3.1. Surgical Techniques of SPSA for Lumbar Spine Surgery

The lumbar SPSA primarily involves three methods of splitting the spinous process (Figure 2).

FIGURE 2.

Lumbar spinous process‐splitting techniques: (A and B) Classic spinous process‐splitting technique: The spinous process is longitudinally split along the midline, with the base detached from the lamina to preserve the bilateral attachment of the paraspinal muscles. Bilateral decompression is achieved, providing access to both sides of the spinal canal and minimizing muscle disruption. (C) Half‐splitting technique: The spinous process is split longitudinally from the midline, with the decompression‐side half fractured and detached from the lamina. (D) Bilateral decompression via unilateral laminectomy.(E) Modified Marmot technique: The spinous process is longitudinally split from the midline and tilted outward while remaining attached to the lamina. (F) Ventral portions of the lamina and ligamentum flavum are resected to create sufficient space between the remaining lamina and dura mater, facilitating decompression.

Classic spinous process‐splitting technique: The spinous process is initially longitudinally split from the midline without detaching the muscles attached to its sides. Subsequently, the base of the spinous process is separated from the lamina, creating the operative space for laminectomy and decompression. Once effective decompression is achieved, the divided spinous process is reattached [30].

This technique offers several advantages: it facilitates bilateral decompression and is suitable for various cases of LSS. It provides ample operative space while optimizing the preservation of the muscles attached to the spinous process, thereby protecting the medial branches of the dorsal rami, which are susceptible to strain. During the bilateral traction process, the split spinous process, supraspinous ligament, and interspinous ligament also serve as mechanical buffers, aiding in reducing sustained contraction pressure on the paraspinal muscles. However, Kawakami et al. [34] have noted a potential drawback of this approach: separating the spinous process from the base of the lamina prevents the transmission of forces from the paraspinal muscles to the spine. While this technique facilitates bilateral decompression and preserves the paraspinal muscles, potential risks include inadequate healing of the re‐sutured spinous process or postoperative spinal instability.

Spinous process half‐splitting technique: The spinous process is initially split longitudinally, preserving the attached muscles. Subsequently, the base of one side of the spinous process is cut to perform unilateral laminectomy. Upon achieving successful decompression, the divided segment of the spinous process is reattached to the remaining part [32]. This technique is particularly suitable for cases with unilateral neurological symptoms and those requiring a unilateral approach for bilateral decompression. In comparison to the classic spinous process‐splitting technique, this method does not detach the base of the spinous process from the lamina on the non‐approach side. However, it may not be suitable for patients with pronounced bilateral lower limb symptoms.

Modified Marmot spinous process‐splitting technique: Initially, the spinous process is longitudinally split from the midline, with the spinous process tilted toward both sides without the need for separation from the lamina. Decompression is then performed in the middle part of the lamina to preserve the posterior cortical bone of the vertebral body [34]. The modified Marmot technique, as the base of the spinous process remains attached to the lamina, causes minimal interference with the function of the spinous process and paraspinal muscles. However, the surgical procedure is relatively complex with a narrow field of view. This technique is only applicable to certain cases of central LSS, limiting its use to cases with extensive lateral or foraminal involvement, and comes with a certain learning curve and technical complexity.

4. Indications and Contraindications for SPSA

The primary indications for SPSA include lumbar LSS, lumbar disc herniation, lumbar spondylolisthesis, intraspinal tumors, and various lumbar spine diseases requiring laminectomy for decompression. Contraindications for SPSA include patients with anatomical anomalies such as the congenital absence or hypoplasia of the spinous process, where the approach would be ineffective or impossible.

5. Clinical Application of SPSA

5.1. SPSA For Lumbar Laminectomy

There are not many studies on SPSA for lumbar surgery (Table 1). In 2005, Watanabe et al. [30] first reported posterior decompression surgery in 38 symptomatic LSS patients, with 18 cases undergoing pure laminectomy using SPSA. The patients, aged 51–79, included 8 males and 10 females, with 10 single‐level and 8 two‐level cases. Twenty cases underwent a conventional midline open approach as a control. A 2‐year follow‐up after SPSA surgery revealed a significantly lower rate of paraspinal muscle atrophy assessed by MRI at 5.3%, compared to 23.9% in the conventional approach. In addition, all split spinous processes demonstrated successful healing. In 2015, Chatani et al. [32] reported 38 cases of LSS patients undergoing unilateral partial laminectomy using the half‐splitting approach. Twenty‐seven cases were single‐level, nine were two‐level, and two were three‐level decompressions. MRI at 1‐year post‐operation showed no significant difference in T2 signal intensity between the approach side and the non‐approach side, and CT scans revealed successful healing of all split spinous processes. The average modified Japanese Orthopedic Association score before surgery (with a maximum of 15) was 8.9 (ranging from 6 to 13), while the average score at the 1‐year postoperative follow‐up was 13.8 (ranging from 10 to 15). The mean recovery rate was 80%, with a range from 38% to 100%. Kawakami et al. [34] divided 53 patients clinically and radiologically diagnosed with LSS into two groups based on the timing of surgery: the modified Marmot SPSA surgery group (26 cases) and the unilateral approach spinous process‐splitting laminectomy group (27 cases). Follow‐up after the surgery revealed that the modified Marmot SPSA resulted in less trauma and better clinical outcomes.

TABLE 1.

Summary of clinical studies on lumbar SPSA laminotomy.

Authors	Comparison groups	Design	No.	Follow‐up (month)	Summary of clinical outcomes	Complications
Cho [26]	(1) Marmot SPSA (2) Traditional approach	Prospective	(1) 40 (2) 30	(1) 15 (2) 14	Marmot SPSA takes a longer time, but it can reduce paraspinal muscle injury, shorten hospital stay, and relieve postoperative back pain	(1) 1 insufficient decompression; 1 superficial wound infection (2) 2 postoperative spondylolisthesis; 1 revision
Banczerowski [46]	SPSA for intradural tumor excision	Retrospective	19	15.4	Preservation of the majority of posterior structures leaves muscle attachments on the spinous processes and laminae completely intact	1 intraoperative dural tear
Watanabe [31]	(1) SPSA (2) Traditional approach	Prospective	(1) 18 (2) 16	(1) 12 (2) 12	SPSA can reduce postoperative acute pain and paravertebral muscle injury	None
Mori [45]	(1) SPSA pedicle screw fusion (2) Traditional pedicle screw fusion	Prospective	(1) 27 (2) 26	(1) 38 (2) 38	SPSA pedicle screw fusion was less Damaging to the paraspinal muscle and had a significant clinical effect, reducing low back discomfort	None
kawakami [34]	(1) Modified Marmot (2) Spinous process transverse cutting	Retrospective	(1) 25 (2) 23	(1) 12 (2) 12	The MM operation was less invasive and produced superior clinical outcomes	None
Liu [48]	(1) Bilateral decompression via unilateral SPSA (2) Traditional approach	Prospective	(1) 27 (2) 29	(1) 24 (2) 24	SPSA effectively reduces multifidus injury and preserves muscle attachment to the contralateral lamina	(1) 3 contralateral dural tear (2) 1 contralateral dural tear
Rajasekaran [49]	(1) SPSA (2) Traditional approach	Prospective	(1) 28 (2) 23	(1) 14 (2) 14	SPSA has a better prognosis for lumbar function	(1) 1 intraoperative dural tear (2) 1 intraoperative dural tear;1 wound dehiscence
Nomura [36]	Microscopic SPSA	Retrospective	124	31 ± 15	SPSA led to significant clinical improvement in patients with LSS	1 postoperative infection; 2 minor spinal fluid leakage
Uehara [50]	(1) SPSA (2) Traditional approach	Retrospective	(1) 55 (2) 20	(1) 25 (2) 25	SPSA was shown to be less invasive and more stable for patients with lumbar spinal stenosis	(1) 1 incision hematoma; 1 deep vein thrombosis; 2 wounds infections (2) 1 surgical site infection
Kanbara [33]	(1) SPSA (2) Traditional approach	Retrospective	(1) 26 (2) 21	(1) 12 (2) 12	The paravertebral atrophy rate of SPSA was significantly lower than that of conventional approach	None
Baghdadi [56]	SPSA	Retrospective	37	12	SPSA provides adequate decompression for the neuronal elements and may avoid extensive paraspinal muscular damage	4 dural tear;3 epidural hematoma; 1 infection;2 additional decompression
Masuda [57]	(1) SPSA (2) Modified Marmot	Retrospective	(1) 37 (2) 32	(1) 24 (2) 24	Although the modified Marmot method resulted in the reduction of wound pain during early postoperative periods, the clinical results did not exhibit greater long‐term improvements, when compared with SPSA	(1) 1 hematoma; 1 surgical site infection; 1 dural tear (2) 1 hematoma; 3 dural tears
Ovalioglu [58]	(1) SPSA (2) Traditional approach	Retrospective	(1) 144 (2) 132	(1) 38.6 ± 7.2 (2) 38.6 ± 7.2	The SPSA and the conventional approach had similar rates of functional recovery clinically and radiographically	(1) 8(5.6%) Dural tear; 1 wound dehiscence (2) 6(4.5%) Dural tear; 1 epidural hematoma; 1 wound abscess
Voglis [51]	(1) SPSA (2) Traditional posterior median approach	Retrospective	(1) 48 (2) 58	(1) 3 (2) 3	The pain was relieved in the acute phase after SPSA	(1) 1 superficial wound dehiscence; 1 cerebrospinal fluid leakage (2) 2 cerebrospinal fluid leakage
Liu [44]	(1) SPSA TLIF (2) Traditional TLIF	Prospective	(1) 52 (2) 54	(1) 30.1 (2) 30.1	SPSA TLIF minimizes damage to the paraspinal muscles, reducing postoperative muscle atrophy and the occurrence of lower back pain	(1) 2 intraoperative dural tear (2) 1 local epidural hematoma; 2 intraoperative dural tear
Liu [59]	Modified hemilateral SPSA TLIF	Retrospective	65	15.6 ± 3.7	This technique can achieve Effective spinal decompression and interbody fusion	1 misplaced pedicle screw that required surgical repositioning
Kurogochi [35]	(1) SPSA (2) Posterolateral lumbar fusion	Retrospective	(1) 47 (2) 63	(1) 12 (2) 12	SPSA displayed comparable results for slip progression and clinical outcomes at 1 year postoperatively	(1) 1 surgical site infection (2) 2 acute epidural hematomas requiring revision surgery; 2 surgical site infection
Son [60]	SPSA for LSS	Retrospective	42	75.3 ± 5.3	SPSA showed favorable clinical and radiological outcomes at the mid‐term follow‐up	5 patients (11.9%) underwent reoperation at a mean of 52.2 months after the SPSA
Okubo [47]	SPSA for intradural tumor excision	Retrospective	41	24	SPSA is a suitable surgical technique for patients	None

5.2. SPSA For Lumbar Decompression and Fusion Surgery

The SPSA approach demonstrates favorable clinical efficacy not only in isolated laminectomy but also in decompression with fusion and internal fixation. Liu et al. [44] discovered that when employing the SPSA for transforaminal lumbar interbody fusion (TLIF) in lumbar spondylolisthesis, advantages over conventional methods included shorter operative time, reduced blood loss, shorter hospital stays, enhanced visualization, and a larger surgical field. Additionally, this technique preserves paraspinal muscle integrity, reducing postoperative muscle atrophy and chronic lower back pain. Mori et al. [45] implemented the SPSA approach for treating degenerative lumbar spondylolisthesis in 53 instances of either single‐level lumbar posterolateral fusion or TLIF surgery. One‐year postoperative data indicated a significantly lower average Visual Analog Scale score for lower back pain in the SPSA group than in the traditional group (1.5 ± 1.6 vs. 2.8 ± 2.3, p < 0.05). MRI findings showed significantly reduced paraspinal muscle atrophy in the SPSA group.

5.3. SPSA For Intradural Tumor Excision

Banczerowski et al. [46] introduced a multilevel laminotomy technique involving the splitting and distraction of spinous processes, applied to 19 patients with various spinal canal pathologies. This innovative approach divides the spinous processes, utilizing Cloward‐type retractors to separate and distract both the spinous processes and laminae. Unlike conventional approaches, this technique preserves most posterior structures, thus maintaining the integrity of muscle attachments on the spinous processes and laminae. Its effectiveness for exposure and decompression has been demonstrated across all spinal regions—cervical, thoracic, and lumbar—spanning diverse age groups. Okubo et al. [47] examined the clinical outcomes associated with spinous process‐splitting laminectomy for treating tumors located at the conus medullaris or cauda equina. The findings indicate that this approach does not adversely affect sagittal spine alignment over a 2‐year follow‐up period and results in positive functional and clinical outcomes. These findings endorse the SPSA as a viable surgical technique for patients with tumors at the conus medullaris or cauda equina. Xu et al. [43] applied SPSA to a patient with a cavernous hemangioma at the T12‐L1 level. Post‐resection, there was no active hemorrhage, and no operation‐related complications were observed during the hospital stay. Postoperative lumbar MRI confirmed complete resection of the lesion. These results suggest that the SPSA technique is suitable for intra‐canal surgeries, particularly in the posterior midline, allowing precise micromanipulations such as tumor excision, nerve exploration, and dural suturing through the surgical corridor.

6. Complications

Although the indications for lumbar SPSA are expanding and its clinical use is increasing, reports of associated complications remain limited, including surgical site infection, dural tear, epidural hematoma, deep vein thrombosis, disc protrusion, revision surgery, and secondary fracture [26, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55]. Cho et al. [26] reported one case of mild superficial wound infection following lumbar decompression through SPSA for LSS, which was successfully treated with antibiotics and dressing changes. Liu et al. [48] reported three cases of dural tears, but no obvious cerebrospinal fluid leakage occurred postoperatively. Rajasekaran et al. [49] reported one case of intraoperative dural tear that was left unrepaired, without resulting in neurological deficits. Voglis et al. [51] reported one case of cerebrospinal fluid leakage. Uehara et al. [50] reported one case requiring revision surgery due to hematoma postoperatively, one case of deep vein thrombosis, one case of progressive slippage, one adjacent vertebral fracture, two cases of disc protrusion, and three cases requiring simultaneous revision surgery for foraminal nerve root compression. Secondary fracture is also a potential complication of spinous process‐splitting laminectomy. Banczerowski et al. [46] treated 19 patients with spinal canal lesions using multi‐segment spinous process‐splitting laminectomy combined with or without iliac bone grafting. Postoperative CT scans revealed 57 spinous processes, among which nine cases (15.8%) had spinous process fractures. Wi et al. [52] studied 73 patients undergoing SPSA decompression for LSS. Bone healing rates and patterns were assessed by CT scans 6–18 months postoperatively, and subgroup comparisons were made based on the number of decompression segments and the degree of spinous process splitting. Bone healing patterns were classified into complete healing (full consolidation of the spinous process), partial healing (incomplete consolidation), and non‐healing (absence of osseous bridging), with occurrence rates of 51.7%, 43.2%, and 5.1%, respectively [53, 54, 55].

7. Experimental Studies Related to SPSA

Liu et al. [29] compared four surgical approaches and their effect on multifidus muscle preservation in sheep and found that approaches minimizing muscle detachment and reconstructing ligamentous structures provided superior muscle preservation based on MRI and histological evaluation. SPSA is an effective method for minimizing postoperative paraspinal muscle atrophy.

8. Technical Challenges and Clinical Prospects of SPSA

SPSA represents a significant advancement in lumbar spine surgery by minimizing paraspinal muscle damage, facilitating neural decompression, and preserving the integrity of the posterior spinal structures. This technique offers distinct advantages in treating specific lumbar spine conditions, particularly lumbar stenosis, as well as other degenerative spinal disorders. However, SPSA presents technical challenges, including how to ideal split the spinous process, complications such as failed bony fusion of the split spinous process, which may result from inadequate fixation or healing and compromise both postoperative stability and long‐term efficacy. The ideal split may be challenging due to the relatively narrow middle part of the spinous process. Wi et al. [52] reported 118 cases of posterior midline approach for lumbar decompression surgery, with only 64% achieving a complete split of the spinous process and the rates of complete union, partial union, and nonunion were 51.7%, 43.2%, and 5.1%.

To address these challenges, future research should focus on techniques for precisely splitting the spinous process, optimizing reduction and fixation of the split spinous process, and developing specialized surgical instruments tailored to the spinous process splitting approach. To establish SPSA as a standardized clinical technique, large‐scale, multicenter, randomized controlled trials, including those focused on preoperative planning and intraoperative guidance, are essential. These studies should evaluate the efficacy, safety, cost‐effectiveness, long‐term alignment maintenance, and patient‐reported quality of life and functional outcomes, specifically comparing SPSA with conventional open techniques and minimally invasive approaches in terms of fusion rates, complication rates, recovery times, and clinical improvement.

9. Conclusion

Posterior midline lumbar SPSA offers an optimal surgical field, is technically straightforward, and does not necessitate specialized instruments. Furthermore, this technique effectively protects the paraspinal muscles by circumventing the resection of the posterior column's spinous process ligamentous–muscle complex. Therefore, these advancements show promising results, suggesting that further clinical trials and broader application of SPSA techniques could improve surgical outcomes and reduce postoperative complications.

Author Contributions

Y.Z.M. and G.Y.L. contributed to the conception and design of the study. Y.Z.M. and L.M. wrote the first draft of the manuscript. L.H.H. and K.X.C. looked up and selected literature from the database. G.Y.L. supervised the manuscript.

Ethics Statement

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.