Minimally Invasive Spine Surgery in Vertebral Bone Disorders: Current Evidence and Future Perspectives

Abstract

Minimally invasive spine surgery (MISS) has progressively transformed the management of spinal disorders by reducing soft-tissue disruption, perioperative morbidity, and recovery time while maintaining clinical outcomes comparable to conventional open techniques. Beyond its technical evolution, MISS has increasingly assumed a central role in the treatment of bone-related spinal conditions, including vertebral fractures, degenerative instability, metastatic disease, and osteoporosis-associated pathology. This narrative review provides a comprehensive overview of the evolution of MISS with a specific focus on its interaction with vertebral bone biology, implant stability, and fusion processes. A structured literature search of the PubMed/MEDLINE database was conducted, including English-language studies published between 1980 and June 2025 addressing MISS techniques, enabling technologies, and bone-related clinical outcomes. Current evidence suggests that MISS may preserve paraspinal vascularization and soft tissue integrity, potentially supporting bone healing and fusion, although high-quality comparative data remain limited. The effectiveness of MISS in osteoporotic and metastatic vertebral disease is closely linked to bone quality, implant anchorage, and biomechanical considerations, particularly in the context of pedicle screw fixation and interbody support. Emerging technologies—including navigation, robotics, and artificial intelligence—may enhance accuracy in implant placement and reduce bone-related complications, but robust evidence of long-term benefit is still lacking. Despite its advantages, MISS presents important limitations, including a steep learning curve, increased costs, and uncertain superiority in terms of fusion rates and long-term biomechanical stability. Future research should prioritize high-quality comparative studies focusing on bone healing, implant integration, and patient-specific factors such as bone density. MISS should therefore be interpreted not only as a surgical paradigm shift but as an evolving strategy for optimizing outcomes in bone-related spinal disorders.

1. Introduction

Minimally invasive spine surgery (MISS) has profoundly transformed contemporary spinal care by reducing soft-tissue trauma, perioperative blood loss, and hospital length of stay, while achieving clinical outcomes comparable to, and in selected cases superior to, those of conventional open approaches [1,2,3]. Initially developed to minimize surgical morbidity, MISS has evolved over the past four decades from early microsurgical decompression techniques into a technologically advanced discipline incorporating endoscopy, computer-assisted navigation, robotics, augmented reality, and artificial intelligence [4,5,6,7,8,9].

This evolution reflects a broader paradigm shift in spinal surgery, extending beyond the concept of limited exposure toward a more comprehensive redefinition of surgical strategy. The preservation of paraspinal musculature and reduction in iatrogenic tissue injury, demonstrated by decreased muscle denervation and atrophy, have been associated with improved functional recovery and may contribute to maintaining physiological spinal biomechanics [10]. At the same time, the increasing adoption of enabling technologies has enhanced surgical precision, particularly in implant placement, while introducing new challenges related to cost, accessibility, and the clinical relevance of technology-driven improvements [5,6,7,8,9,11,12].

Importantly, the role of MISS must be interpreted within the broader context of vertebral bone biology and biomechanics. Bone quality is a critical determinant of surgical success, particularly in aging populations and in patients with osteoporosis or metastatic disease. Reduced bone mineral density has been strongly associated with increased rates of pedicle screw loosening, implant failure, and construct instability [13,14,15]. Biomechanical factors, including load distribution and implant–bone interface integrity, further influence outcomes, especially in the setting of minimally invasive fixation strategies [16]. In this context, techniques such as cement augmentation and optimized screw trajectory have been developed to improve fixation in compromised bone [16].

Similarly, interbody fusion, one of the cornerstones of modern spine surgery, is closely dependent on the biological environment and mechanical stability. The use of osteoinductive agents such as recombinant human bone morphogenetic protein-2 has demonstrated the potential to enhance fusion rates, although long-term outcomes and complication profiles remain areas of ongoing investigation [17,18]. Minimally invasive fusion techniques, including MI-TLIF, have shown comparable clinical outcomes to open approaches, but concerns persist regarding cage subsidence, endplate violation, and the influence of reduced exposure on fusion bed preparation [19,20,21,22].

The clinical applications of MISS have expanded considerably and now encompass degenerative, traumatic, oncologic, and deformity-related spinal disorders [3,23]. In metastatic spinal disease, MISS enables effective decompression and stabilization with reduced perioperative morbidity, representing a significant advantage in medically fragile patients [24,25]. In spinal trauma, minimally invasive stabilization techniques have demonstrated favorable outcomes in selected thoracolumbar fracture patterns, although complex injuries often still require open or hybrid approaches [26,27]. In degenerative and deformity settings, MISS offers reduced perioperative burden, but careful patient selection remains essential to balance surgical goals with biomechanical demands [28,29,30].

Despite these advances, several critical questions remain unresolved. While short-term perioperative benefits of MISS are well established, evidence regarding long-term outcomes, particularly fusion rates, implant durability, and biomechanical performance, is still limited and heterogeneous. Moreover, the increasing integration of advanced technologies has largely been evaluated through surrogate technical metrics, such as implant placement accuracy, rather than clinically meaningful endpoints [6,7,11,12].

Therefore, a comprehensive evaluation of MISS should extend beyond its technical evolution to include its impact on bone biology, implant–bone interaction, and long-term structural stability.

The aim of this narrative review is to provide a chronological and state-of-the-art analysis of minimally invasive spine surgery, with particular emphasis on bone-related factors, including vertebral integrity, fusion biology, implant anchorage, and biomechanical performance, in order to better define its current role and future directions in modern spine care.

2. Materials and Methods

2.1. Study Design

This manuscript was designed as a narrative state-of-the-art review aimed at synthesizing the historical evolution, current clinical applications, and emerging technologies in minimally invasive spine surgery (MISS), with a specific focus on bone-related aspects, including vertebral integrity, fusion biology, implant stability, and biomechanical performance.

A narrative approach was deliberately selected due to the marked heterogeneity of surgical techniques, technological platforms, clinical indications, and outcome measures reported in the literature. This variability limits the feasibility of a meaningful quantitative synthesis or meta-analysis. Accordingly, this design allows for a comprehensive and critical appraisal of both established evidence and emerging concepts, particularly in areas where high-level data remain limited.

2.2. Literature Search Strategy

A structured literature search was conducted using the PubMed/MEDLINE database to identify relevant studies published between January 1980 and June 2025. After full-text assessment, approximately 130 studies were included in the qualitative synthesis.

The search strategy combined free-text terms and Medical Subject Headings (MeSH) related to minimally invasive spine surgery and associated technologies. The following keywords were used in various combinations: “minimally invasive spine surgery,” “microsurgical discectomy,” “tubular retractor,” “endoscopic spine surgery,” “minimally invasive lumbar fusion,” “MI-TLIF,” “robot-assisted spine surgery,” “spinal navigation,” “augmented reality,” “artificial intelligence,” “minimally invasive cervical spine surgery,” “atlanto-axial fixation,” “spinal deformity,” “spinal metastasis,” and “thoracolumbar trauma.”

Boolean operators (AND/OR) were applied to refine the search strategy. In addition, the reference lists of all included articles were manually screened to identify further relevant publications not captured in the initial search.

Particular emphasis was placed on studies reporting bone-related outcomes, including fusion rates, implant-related complications (e.g., screw loosening and cage subsidence), and biomechanical considerations influencing construct stability. Seminal studies on bone biology, osteoinduction, and implant–bone interaction were also included to provide a comprehensive framework for interpreting MISS outcomes in the context of vertebral bone health.

2.3. Eligibility Criteria

Studies were considered eligible if they met the following criteria:

• Publication in peer-reviewed journals.
• English language.
• Focus on MISS techniques, enabling technologies, or clinical applications.
• Inclusion of clinical studies (randomized controlled trials, prospective or retrospective cohort studies), systematic reviews, or seminal technical reports.

The following exclusion criteria were applied:

• Case reports with very small sample sizes, unless of clear historical or technical relevance.
• Purely cadaveric or biomechanical studies without clinical correlation.
• Editorials, expert opinions without supporting data, or non–peer-reviewed literature.

To ensure relevance to the scope of this review, priority was given to studies reporting clinically meaningful outcomes and, when available, data related to bone quality, fusion success, and implant performance.

2.4. Study Selection and Data Extraction

Study selection was independently performed by two experienced authors through initial screening of titles and abstracts, followed by full-text evaluation when appropriate. Any discrepancies regarding study eligibility were resolved through consensus discussion.

For each included study, the following data were extracted:

• Surgical technique and approach.
• Anatomical region involved.
• Clinical indication.
• Study design.
• Perioperative outcomes (e.g., blood loss, operative time, complications).
• Clinical and functional outcomes.
• Bone-related outcomes, when available (e.g., fusion rates, implant stability, hardware-related complications such as screw loosening or cage subsidence).

Given the heterogeneity of study designs, patient populations, and outcome measures, data were synthesized qualitatively rather than quantitatively.

2.5. Methodological Considerations

This review does not adhere to PRISMA guidelines, as it was not designed as a systematic review or meta-analysis. However, a structured and transparent search strategy, predefined eligibility criteria, and independent study selection were implemented to enhance methodological rigor and minimize selection bias.

The narrative nature of this review inherently introduces limitations, including potential selection bias and the absence of quantitative effect estimation. Nevertheless, this approach allows for the integration of diverse sources of evidence, including clinical studies, technological reports, and foundational research on bone biology, providing a comprehensive overview of MISS within the broader context of vertebral bone health and surgical reconstruction.

2.6. Use of Generative AI in Manuscript Preparation

The authors used generative artificial intelligence (ChatGPT, GPT-5.5, OpenAI, San Francisco, CA, USA) as a language-support tool to assist in improving the clarity, grammar, and structure of the manuscript. The AI tool was not used for data analysis, interpretation of results, or generation of scientific content. All content was critically reviewed, revised, and approved by the authors, who take full responsibility for the integrity and accuracy of the manuscript.

3. Discussion

3.1. Foundational Era: Late 20th Century

The foundational phase of minimally invasive spine surgery (MISS) emerged in the late 20th century with the introduction of microsurgical lumbar discectomy and muscle-sparing posterior approaches. These early techniques established the principle of minimizing iatrogenic soft-tissue injury while preserving spinal stability and paraspinal muscle function, which are increasingly recognized as critical determinants of postoperative recovery and biomechanical balance [1,5].

The adoption of operative microscopy and reduced-profile retractors demonstrated that effective neural decompression could be achieved through limited surgical corridors, resulting in reduced postoperative pain and faster functional recovery compared with traditional open approaches [1,2]. These findings provided the conceptual basis for MISS by demonstrating that surgical efficacy does not necessarily depend on extensive exposure.

Although these techniques were not specifically designed to address bone reconstruction, preservation of paraspinal musculature and vascular supply may have indirectly supported a more favorable biological environment for bone remodeling and segmental stability [10]. This early phase therefore laid the groundwork for later integration of MISS with fusion strategies and implant-based stabilization.

3.2. Expansion Phase: 1990s–Early 2000s

The expansion phase was characterized by the development of tubular retractor systems and muscle-splitting approaches, which enabled targeted decompression for lumbar spinal stenosis and foraminal pathology while minimizing tissue disruption [5,23].

Microendoscopic discectomy, introduced by Foley and Smith, represented a major milestone by combining endoscopic visualization with reduced surgical invasiveness [4]. Subsequent studies demonstrated that minimally invasive decompression techniques were associated with reduced blood loss and shorter hospitalization, while maintaining comparable clinical outcomes to open surgery [2,3].

Importantly, reduced paraspinal muscle injury, documented by decreased denervation and atrophy, has been associated with improved postoperative biomechanics and more physiological load distribution across the spinal column [10]. These factors may have indirect implications for vertebral stress and long-term structural integrity.

However, during this phase, MISS remained primarily focused on neural decompression, with limited application to fusion or structural reconstruction. As a result, the direct impact of these techniques on bone-related outcomes remained largely unexplored.

3.3. Consolidation Phase: Mid-2000s

The introduction of minimally invasive fusion techniques, particularly minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), represented a critical transition in the evolution of MISS. These approaches extended minimally invasive principles to spinal stabilization, enabling interbody fusion through muscle-sparing corridors [5,19,20].

Clinical evidence has shown that minimally invasive fusion techniques achieve outcomes comparable to open procedures, with reduced blood loss and shorter hospital stays, although they are associated with increased technical complexity and a significant learning curve [3,28].

From an osteological perspective, the reduced disruption of soft tissues and vascular structures has been hypothesized to promote bone healing and fusion. However, current evidence does not consistently demonstrate superior fusion rates compared with open techniques, suggesting that biological advantages may be offset by technical limitations, such as restricted visualization and suboptimal endplate preparation [3,19].

Moreover, complications such as cage subsidence and endplate violation have emerged as relevant concerns in minimally invasive interbody fusion. These complications are closely related to bone quality and implant–bone interface mechanics, particularly in osteoporotic patients [21,22]. The use of osteoinductive agents, such as recombinant human bone morphogenetic protein-2, has been shown to enhance fusion rates, but concerns regarding cost, safety, and long-term outcomes remain [17,18]. Despite these advances, improved technical accuracy should not be assumed to translate into superior fusion rates, implant durability, or long-term biomechanical stability. Most available studies focus on surrogate endpoints such as screw placement accuracy, whereas robust evidence linking these technologies to clinically meaningful bone-related outcomes remains limited [6,7,11,12].

3.4. Technological Integration Era: 2010s–2020s

In the last decade, MISS has been increasingly shaped by the integration of advanced technologies, including robotic-assisted surgery, navigation systems, augmented reality, and artificial intelligence [6,7,8,9].

Robotic and navigation-assisted techniques have demonstrated high accuracy in pedicle screw placement, often exceeding 90%, and may reduce the risk of malposition-related complications [6,7,11,12]. This is particularly relevant in patients with compromised bone quality, where optimal screw positioning is essential to maximize fixation strength and reduce the risk of loosening.

Bone quality remains a central determinant of implant performance. Reduced bone mineral density has been strongly associated with pedicle screw loosening, implant failure, and decreased construct stability [13,14,15]. Biomechanical studies have shown that strategies such as cement augmentation can improve screw fixation in osteoporotic bone, although these techniques introduce additional risks and technical considerations [16].

Despite these advances, the clinical impact of improved technical precision remains uncertain. Most available studies focus on surrogate outcomes, such as screw placement accuracy, rather than clinically meaningful endpoints including fusion success, implant survival, or long-term functional outcomes. This discrepancy highlights a critical gap between technological innovation and clinical validation.

3.5. Osteoporosis-Related Spinal Disorders

Osteoporosis represents one of the most critical challenges in contemporary spine surgery, particularly in the context of MISS. Reduced bone mineral density significantly impairs the mechanical properties of vertebral bone, weakening the implant–bone interface and increasing the risk of pedicle screw loosening, cage subsidence, endplate violation, and construct failure [13,14,15,31].

While MISS reduces soft tissue disruption, it does not compensate for compromised bone quality. Therefore, preoperative assessment of bone health, including dual-energy X-ray absorptiometry and CT-based Hounsfield unit analysis, has emerged as a key component of surgical planning. Lower Hounsfield unit values have been associated with increased risk of cage subsidence and instrumentation failure following lumbar interbody fusion [31,32].

Strategies to optimize fixation in osteoporotic bone include cement augmentation, expandable pedicle screws, cortical bone trajectory techniques, and the use of larger interbody cages to distribute load more effectively across the endplate [16,32]. However, these approaches introduce additional risks and technical considerations, emphasizing the need for individualized surgical planning.

3.6. Metastatic Vertebral Disease

In metastatic spinal disease, MISS has become an integral component of multidisciplinary management. Minimally invasive techniques allow for effective neural decompression and stabilization with reduced perioperative morbidity, facilitating earlier mobilization and timely initiation of adjuvant therapies [24,25].

However, tumor-related osteolysis significantly compromises vertebral structural integrity and implant anchorage. The presence of lytic lesions reduces screw purchase and increases the risk of hardware failure. As a result, surgical decision-making must integrate oncological factors, spinal stability, expected survival, and bone quality.

Cement augmentation and hybrid stabilization techniques may improve fixation in selected cases, although long-term durability remains uncertain.

3.7. Spinal Trauma

Minimally invasive stabilization techniques have demonstrated favorable outcomes in selected thoracolumbar fractures, particularly in patients requiring posterior stabilization without extensive decompression [26,27].

Percutaneous fixation reduces blood loss, muscle injury, and postoperative pain. However, its application is limited in cases of severe instability, significant canal compromise, or the need for direct neural decompression.

Bone quality plays a decisive role in traumatic settings, especially in elderly patients with osteoporotic fractures, where fixation failure and progressive deformity remain significant concerns.

3.8. Adult Spinal Deformity

The role of MISS in adult spinal deformity remains controversial and highly dependent on patient selection. Minimally invasive and hybrid approaches may reduce perioperative morbidity, particularly in elderly or medically fragile patients [28,29,30].

However, deformity correction is strongly influenced by bone quality, global spinal alignment, and long-term construct stability. Osteoporosis increases the risk of pedicle screw loosening, proximal junctional failure, rod fracture, and pseudarthrosis.

Therefore, while MISS may be appropriate in selected cases, achieving adequate correction and durable fixation should not be compromised solely to reduce surgical invasiveness.

3.9. Elderly and Frail Patients

The aging population represents a growing indication for spine surgery. In this context, MISS offers potential advantages by reducing surgical invasiveness, blood loss, postoperative pain, and length of hospital stay.

These features may allow selected elderly or frail patients, who might otherwise be considered high risk for open surgery, to undergo surgical treatment with an acceptable perioperative risk profile [2,33]. Early complications are primarily perioperative and include blood loss, cardiopulmonary events, and wound-related complications, whereas late complications are predominantly biomechanical and include pedicle screw loosening, cage subsidence, pseudarthrosis, and adjacent segment degeneration.

However, advanced age alone should not be considered an indication for MISS. Frailty, comorbidities, sarcopenia, and bone quality are critical determinants of outcomes. Importantly, while MISS may reduce early complications, long-term outcomes such as fusion success, implant stability, and revision rates remain strongly influenced by bone quality.

Osteoporosis in elderly patients is associated with increased rates of screw loosening, cage subsidence, and adjacent segment failure, highlighting the need for comprehensive preoperative optimization.

3.10. Spinal Cord Injury

In patients with spinal cord injury, the primary goals of surgery remain timely decompression, stabilization, and prevention of secondary neurological damage.

MISS should be considered only when it allows achievement of these goals without delaying intervention. In selected cases, percutaneous stabilization may reduce surgical morbidity, particularly in polytrauma or medically fragile patients.

However, open or hybrid approaches remain necessary when direct decompression, deformity correction, or extensive reconstruction is required. Therefore, MISS should be viewed as a complementary technique rather than a universal alternative in spinal cord injury management [34].

3.11. Critical Appraisal

Although the short-term advantages of MISS are well established, its long-term impact on bone-related outcomes remains insufficiently defined. A major limitation of the current literature is the reliance on surrogate technical outcomes, such as implant placement accuracy, rather than clinically meaningful endpoints including fusion rates, implant durability, and biomechanical stability.

While reduced soft-tissue disruption may theoretically enhance bone healing, this advantage is not consistently reflected in improved fusion rates. This discrepancy suggests that technical limitations—such as restricted visualization and suboptimal endplate preparation—may offset potential biological benefits.

Bone quality remains a key determinant of surgical success but is often underreported or inadequately stratified in comparative studies. Furthermore, complications such as cage subsidence and screw loosening lack standardized definitions, limiting cross-study comparisons.

Finally, the increasing adoption of advanced technologies raises important concerns regarding cost-effectiveness, as improved precision does not necessarily translate into improved long-term outcomes.

3.12. Limitations and Future Directions

Despite its widespread adoption, MISS continues to face several challenges, including high costs, variability in training, and limited access to advanced technologies. The lack of long-term randomized controlled trials represents a major limitation in the current evidence base.

Future research should prioritize:

• Long-term evaluation of fusion outcomes and implant durability.
• Incorporation of bone quality assessment into surgical decision-making.
• Development of patient-specific strategies based on biomechanical and biological factors.
• Rigorous cost-effectiveness analyses of emerging technologies.

A stronger emphasis on bone-related outcomes will be essential to define the true role of MISS in modern spine surgery.

From a clinical perspective, the indication for MISS should be carefully tailored based on both pathology and bone quality. In patients with osteoporosis or metastatic disease, strategies aimed at optimizing implant fixation and load distribution are essential to ensure long-term stability.

Overall, available evidence suggests that while MISS may reduce perioperative morbidity, its effects on fusion success, implant stability, and bone-related complications remain heterogeneous across studies. A summary of key studies comparing bone-related outcomes in minimally invasive and open spine surgery is presented in

Table 1. Bone-related outcomes in minimally invasive versus open spine surgery.

Study	Technique	Population	Fusion Rate	Screw Loosening	Cage Subsidence	Key Findings
Goldstein et al. [3]	MIS vs. Open (mixed)	Degenerative spine	Comparable	Not consistently reported	Not consistently reported	MIS shows similar clinical outcomes with reduced morbidity
Parker et al. [28]	MI-TLIF vs. Open TLIF	Lumbar degenerative disease	Comparable	Low	Present in both groups	MIS reduces blood loss and LOS, no clear superiority in fusion
Phan & Mobbs [2]	MIS decompression vs. open	Lumbar stenosis	Not applicable	Not applicable	Not applicable	Similar functional outcomes with reduced perioperative morbidity
Fan et al. [10]	MIS vs. Open fusion	Lumbar fusion	Comparable	Not reported	Not reported	Reduced muscle injury may influence biomechanics
Bredow et al. [13]	Screw fixation (osteoporotic)	Osteoporotic patients	Reduced	Increased risk	Not applicable	BMD strongly predicts screw loosening
Galbusera et al. [14]	Biomechanics	Mixed	Not applicable	High in poor bone	Not applicable	Loosening is clinically relevant and multifactorial
Chang et al. [15]	Osteoporosis effect	Osteoporotic spine	Reduced	Increased	Increased	Bone quality is a critical determinant of fixation
Elder et al. [16]	Cement augmentation	Osteoporotic spine	Improved indirectly	Reduced	Not applicable	Augmentation improves fixation strength
Kim et al. [21]	Interbody fusion	Lumbar fusion	Comparable	Not applicable	Significant	Cage subsidence linked to endplate quality
Marchi et al. [22]	Lateral fusion	Degenerative spine	Comparable	Not applicable	Higher in stand-alone constructs	Subsidence associated with bone quality

Abbreviations: MIS, minimally invasive surgery; TLIF, transforaminal lumbar interbody fusion; BMD, bone mineral density.

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4. Conclusions

Minimally invasive spine surgery has evolved from early microsurgical techniques into a cornerstone of contemporary spinal care. While its advantages in reducing perioperative morbidity are well established, its impact on bone-related outcomes—including fusion, implant stability, and long-term biomechanical performance—remains incompletely understood.

The future of MISS will depend on the integration of technological innovation with a deeper understanding of bone biology and biomechanics. Ensuring that increasing technical sophistication translates into durable, clinically meaningful outcomes represents the primary challenge for the field.