Introduction
Minimally invasive spine surgery (MISS) has become one of the most transformative developments in modern spinal practice, driven by continuous advancements in surgical techniques, instrumentation, and perioperative technology. MISS was initially introduced to reduce tissue disruption associated with traditional open approaches. It has since evolved into a comprehensive surgical philosophy focused on minimizing collateral damage to paraspinal musculature, ligaments, and supporting osseous structures, while achieving equivalent or superior therapeutic goals. Early innovations, such as Foley and Smith’s microendoscopic discectomy, demonstrated the feasibility of obtaining effective neural decompression through smaller surgical corridors, thus marking a pivotal moment in the transition toward less invasive spinal procedures [1].
Over the past 2 decades, the clinical applicability of MISS has expanded substantially. Improvements in endoscopic visualization, development of tubular retractor systems, and widespread integration of navigation and robotic-assisted technologies have broadened the range of spinal disorders amenable to minimally invasive techniques. MISS is now utilized in the management of degenerative lumbar conditions, thoracolumbar trauma, select spinal tumors, and localized infections, with numerous studies reporting reduced intraoperative blood loss, shorter hospital stays, lower postoperative pain, and faster functional recovery compared with open surgery [2–4]. These clinical advantages have contributed to the increasing adoption of ambulatory or short-stay spine surgery models, aligning MISS with the broader healthcare goals of cost-effectiveness and enhanced patient satisfaction.
Despite its benefits, MISS is accompanied by several challenges and limitations. Restricted visualization, narrow working channels, and dependence on fluoroscopy for navigation increase technical complexity and may contribute to longer operative times during the early phases of adoption. Furthermore, MISS requires a steep learning curve, often requiring dedicated training, specialized equipment, and institutional investment. Concerns regarding increased radiation exposure to the surgeon and patient have also been raised, particularly during percutaneous instrumentation and endoscopic procedures [5]. Additionally, the indications for MISS must be carefully selected. Complex deformities, extensive tumors, and multilevel pathologies may still necessitate open exposure to achieve optimal surgical outcomes [6]. Therefore, appropriate patient selection and the surgeon’s experience remain critical determinants of safety and clinical success.
Given the rapid evolution of MISS and its increasing global adoption, a comprehensive evaluation of its strengths and limitations is essential for clinicians, trainees, and healthcare systems. This review aims to synthesize current evidence regarding the advantages and disadvantages of MISS, with an emphasis on clinical outcomes, procedural considerations, cost implications, and practical challenges in implementation. By critically assessing the benefits and potential drawbacks of MISS, this article seeks to support informed decision-making and contribute to the continued refinement of minimally invasive spinal care.
Current Minimally Invasive Spine Surgery: Techniques, Benefits, and Challenges
Minimally invasive transforaminal lumbar interbody fusion
Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is a surgical technique designed to treat degenerative lumbar diseases such as spondylolisthesis, disc degeneration, and segmental instability. Unlike traditional open transforaminal lumbar interbody fusion (TLIF), MI-TLIF employs small incisions and a tubular retractor system, thereby minimizing paraspinal muscle dissection while allowing access to the intervertebral disc space for cage insertion and posterior fixation with pedicle screws. MI-TLIF enables adequate neural decompression while reducing the strain on surrounding tissues, with the ultimate aim of improving postoperative recovery and reducing surgical morbidity. Since its introduction in the mid-2000s, this approach has been increasingly adopted due to its potential benefits over conventional open techniques [1].
MI-TLIF has been associated with favorable outcomes for intraoperative blood loss, postoperative recovery, and functional improvement. A meta-analysis examining single-level, grade 1–2 spondylolisthesis demonstrated that although the operative time for MI-TLIF is slightly longer than that of open TLIF, blood loss was significantly less and the hospital stay was shorter with comparable or superior long-term functional outcomes [2]. Systematic reviews among elderly populations (≥65 years) have further confirmed that MI-TLIF results in significant improvements in Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) scores, achieving clinically significant differences while maintaining high fusion rates of approximately 86% [3]. Specifically, in patients with isthmic spondylolisthesis, MI-TLIF has demonstrated a mean operative time of approximately 110 minutes and a mean blood loss of approximately 56 mL, with substantial postoperative improvements in VAS and ODI scores [4].
Despite its benefits, MI-TLIF has notable limitations. The technique has a steep learning curve, and precise manipulation within a narrow tubular corridor requires considerable surgical expertise [5]. Additionally, the use of tubular retractors limits visualization, which can constrain the surgeon’s ability to adequately decompress contralateral neural elements [6]. The procedure’s heavy reliance on fluoroscopy further compounds these challenges, as studies have shown that MI-TLIF may expose patients and surgeons to higher cumulative radiation doses compared to open TLIF [7]. Complications, while relatively low, are not negligible. A previous systematic review reported that radiculitis, screw malposition, and incidental durotomy are the most frequently reported complications of MI-TLIF [8].
Endoscopic spine surgery
Endoscopic spine surgery has emerged as a less invasive alternative to tubular retractor–assisted techniques such as MI-TLIF. Similar to arthroscopic procedures used in orthopedic surgery, endoscopic approaches utilize continuous saline irrigation with an endoscopic camera and specialized surgical instruments to perform decompression and other spinal procedures. Endoscopic spinal techniques are broadly categorized into full endoscopic spinal surgery, which employs a single working portal, and biportal endoscopic spine surgery or unilateral biportal endoscopy, which uses two separate portals, one for the endoscope and one for the instrument. The most commonly used approaches are transforaminal and interlaminar approaches [9]. Endoscopic spine surgery enables not only decompression but also lumbar interbody fusion with cage insertion [10,11]. These endoscopic approaches have rapidly evolved in recent years, and they are increasingly being adopted not only for lumbar pathologies but also for cervical and thoracic spine disorders [12,13].
Endoscopic spine surgery offers several clinically meaningful advantages over conventional open or tubular-retractor–assisted approaches. By using small portals and continuous saline irrigation combined with highly magnified endoscopic visualization (Fig. 1), endoscopic techniques minimize paraspinal muscle and soft-tissue disruption, which has been associated with reduced intraoperative blood loss and lower postoperative pain scores [14]. Reduced tissue trauma and smaller incisions result in shorter hospital stays, more rapid functional recovery, and earlier return to work in many series and meta-analyses [15–18]. Several studies indicate that endoscopic procedures can achieve clinical outcomes, such as pain relief and functional improvement, comparable to open surgery, while still providing the perioperative advantages described above, making them particularly attractive for elderly patients or those who could benefit from less intensive care [19–21]. Finally, the enhanced visualization and targeted decompression offered by the endoscopic platform allow surgeons to treat an increasingly wide spectrum of spinal conditions across the lumbar, thoracic, and cervical regions, reinforcing the expanding role of this modality within MISS [22].
Endoscopic spine surgery, despite its rapid adoption, does have several important limitations. The technique requires a steep learning curve, as surgeons must operate with limited tactile feedback and only rely on two-dimensional endoscopic visualization. Early in the learning phase, prolonged operative times and higher complication rates have been reported [23–25]. The restricted working corridor and dependence on specialized instruments might limit the surgeon’s ability to address complex pathologies. The most commonly reported complications include dural tears, postoperative hematomas, neurological irritation such as dysesthesia, and persistent or unresolved pain [26]. With an interlaminar approach, excessive irrigation pressure can increase cerebrospinal fluid and intracranial pressures, potentially leading to postoperative headaches or seizures. Therefore, it is essential to closely monitor early postoperative neurological symptoms and prevent elevated intraoperative pressure by improving outflow rather than increasing infusion pressure, minimizing operative time, and maintaining irrigation pump pressures below 30 mmHg [14].
Minimally invasive lateral approach for lumbar interbody fusion
Minimally invasive lateral approaches for lumbar spine surgery have evolved over the past 2 decades as alternatives to the traditional posterior approaches, aiming to reduce tissue disruption while allowing access to the intervertebral disc and vertebral body. Techniques such as direct lateral interbody fusion (DLIF), extreme lateral interbody fusion (XLIF), and oblique lateral interbody fusion (OLIF) have been developed to facilitate lateral access to the lumbar spine through retroperitoneal corridors. DLIF and XLIF use a true lateral trajectory through the psoas muscle to access the disc space, employing specialized instrumentation and neuromonitoring to minimize the risk of nerve injury [27]. OLIF, in contrast, utilizes an oblique corridor anterior to the psoas, thereby allowing access to the disc space without traversing the psoas muscle [28,29]. These approaches emerged from the integration of minimally invasive surgical principles with advances in spinal imaging, neuromonitoring, and tubular retractor systems, providing surgeons with alternative trajectories for interbody fusion procedures in the lumbar spine [30].
Minimally invasive lateral lumbar fusion techniques, such as DLIF, XLIF, and OLIF, confer several perioperative and early postoperative benefits compared with traditional posterior approaches. These lateral methods typically result in significantly less intraoperative blood loss and a shorter hospital length of stay due to reduced muscle dissection and utilization of natural anatomical corridors [31–33]. In particular, OLIF minimizes soft-tissue trauma by avoiding major posterior structures, which facilitates faster mobilization and recovery [34]. Additionally, lateral fusion allows for the insertion of larger interbody cages, which can improve disc height restoration and indirect neural decompression while preserving posterior ligamentous and muscular integrity (Fig. 2) [32,35]. From a health-economic perspective, lateral lumbar fusion has also been associated with reduced long-term costs compared with posterior fusion, driven in part by shorter hospitalization and fewer perioperative resource demands. Furthermore, the use of larger interbody cages in minimally invasive lateral lumbar fusion allows for effective restoration of both sagittal lumbar lordosis and coronal spinal alignment [36,37].
Despite their minimally invasive nature, lateral lumbar interbody fusion techniques, such as DLIF, XLIF, and OLIF, carry procedural limitations and complications that warrant careful consideration. The lateral transpsoas and oblique approaches place the lumbar plexus and associated nerves, including the genitofemoral, lateral femoral cutaneous, ilioinguinal, and iliohypogastric nerves, at risk of injury. Reported rates of new sensory deficits and motor weakness have been as high as 30%–40% in the XLIF series and anterior thigh or groin pain in 12%–34% of patients, some of which may be permanent [38]. OLIF, while avoiding direct psoas trauma, still demonstrates neurologic sequelae, such as psoas and thigh symptoms, and has been associated with visceral and vascular risks, including ureter and peritoneal injury in rare but significant instances [39,40]. These approaches often necessitate intraoperative patient repositioning and extensive fluoroscopic guidance, contributing to longer operative times and increased radiation exposure compared with posterior approaches [41]. Furthermore, both techniques are subject to other adverse outcomes, such as cage malposition, subsidence, and reoperation, indicating their meaningful complication profile must be balanced against their minimally invasive advantages.
Minimally invasive scoliosis surgery
Minimally invasive scoliosis surgery represents a strategy aimed at correcting spinal deformity with reduced soft-tissue disruption relative to conventional, open, posterior spinal fusion. Minimally invasive surgical techniques in patients with adolescent idiopathic scoliosis (AIS) include posterior, mini-open approaches, thoracoscopic anterior approaches, and vertebral body tethering (VBT). Mini-open incisions with tubular retractors and “coin-hole” approaches are designed to overcome the limitations of conventional, open scoliosis surgery by minimizing paraspinal muscle stripping while still allowing pedicle screw fixation, rod assembly, rod derotation maneuvers, and, when necessary, thoracoplasty [42]. Thoracoscopic anterior spinal approaches, including VBT, provide a minimally invasive method to access the thoracic spine through small portals to correct AIS while preserving segmental motion [43].
Minimally invasive scoliosis surgery provides multiple advantages compared with conventional open posterior scoliosis correction. Current evidence demonstrates that minimally invasive scoliosis surgery achieves substantial deformity correction with coronal alignment outcomes comparable to those of open surgery while also yielding improved patient-reported outcomes, including higher Scoliosis Research Society-22 domain scores. The use of smaller incisions and muscle-sparing techniques significantly reduced intraoperative blood loss, lowered perioperative morbidity, and resulted in shorter hospital stays. Additionally, decreased soft tissue disruption may enhance cosmetic results and facilitate more rapid postoperative functional recovery (Fig. 3) [42,44,45]. Furthermore, thoracoscopic VBT offers meaningful deformity correction with preservation of spinal motion, minimized soft-tissue injury, and favorable early recovery profiles in carefully selected skeletally immature patients [46].
Despite these advantages, minimally invasive scoliosis surgery has several limitations. It is technically demanding and requires specialized instrumentation and operative skills, resulting in a substantial learning curve characterized by initially prolonged operative times and increased radiation exposure due to a reliance on image guidance. Early clinical evaluations of the learning process demonstrated gradual improvements in efficiency but consistently underscored the procedural complexity inherent to mastering MISS. Moreover, the limited surgical exposure might reduce its effectiveness in patients with severe or rigid deformities, as it might constrain the ability to perform extensive osteotomies or robust derotation maneuvers. Although uncommon, complications such as hemothorax and pedicle screw malposition have been reported in retrospective analyses [47,48]. Additionally, thoracoscopic approaches and VBT carry specific risks, including pulmonary complications, tether breakage, overcorrection, and comparatively high revision rates, and the current literature continues to emphasize the need for long-term data to determine their durability [49].
Navigation
Navigation-assisted MISS refers to the integration of real-time image guidance with percutaneous and muscle-sparing spinal procedures to enhance the placement of instrumentation and the accuracy of surgical maneuvers. These computer-assisted navigation systems typically use intraoperative three-dimensional (3D) imaging, such as O-Arm or 3D C-Arm, combined with tracking technology to provide 3D visualization of pedicle screw trajectories and anatomical landmarks, thereby overcoming the limited direct exposure inherent to MISS. Navigation enables surgeons to plan and execute screw placement, decompression, and alignment with greater precision while potentially reducing reliance on continuous fluoroscopy [50].
Navigation significantly enhances the accuracy of spinal instrumentation in MISS, particularly pedicle screw placement, as demonstrated by multiple studies reporting higher placement precision compared with conventional fluoroscopy guidance. In navigated MISS, pedicle screw misplacement rates are generally lower, which reduces neurologic and vascular injury risk. Navigation also decreases intraoperative radiation exposure to surgeons and operating room staff by reducing dependence on continuous fluoroscopy, while still allowing detailed, 3D anatomical visualization once intraoperative imaging is acquired. Moreover, navigated systems may streamline workflows and shorten the learning curve for complex MISS procedures, especially in anatomically challenging regions such as the thoracic spine [51,52].
Despite these advantages, navigation-assisted MISS has limitations that can impact its adoption and outcomes. Navigation systems require additional intraoperative setup, imaging acquisition, and registration steps, which can initially increase operative time compared with traditional techniques. The capital costs for navigation hardware, maintenance, and staff training are substantial, making it less accessible in some centers. There is also the potential for navigation inaccuracy due to reference frame displacement, registration errors, or patient motion, which can compromise instrumentation accuracy if not recognized. While navigation reduces the surgeon’s radiation exposure by eliminating the need to work under real-time fluoroscopy, intraoperative 3D imaging modalities such as O-arm or computed tomography-based scanning might increase the patient’s radiation exposure compared with standard fluoroscopy alone. Finally, effective use of navigation requires an experienced surgical team familiar with system workflows to avoid workflow delays and ensure safety [50,51].
Robotic spine surgery
Robotic spine surgery refers to the use of computerized robotic systems to assist surgeons in planning and executing spinal procedures, most commonly the placement of pedicle screws during fusion surgery. These systems integrate preoperative imaging and intraoperative guidance to position instruments and implants with high precision, thereby aiming to reduce human error and enhance procedural safety (Fig. 4). First introduced in the early 2000s, robotic platforms such as Mazor, ROSA, and ExcelsiusGPS have been increasingly adopted worldwide for thoracolumbar applications, enabling surgeons to execute complex trajectories with preplanned accuracy while potentially improving reproducibility with a minimally invasive surgical approach. Multiple systematic reviews indicate that robotic assistance enhances pedicle screw accuracy and may reduce radiation exposure compared with conventional techniques [53,54].
Robotic spine surgery has several potential advantages over traditional freehand or fluoroscopy-guided methods. Most notably, studies have demonstrated a greater accuracy of pedicle screw placement, with robotic systems achieving precise alignment and reduced cortical breaches due to preplanned trajectories and stable robotic guidance. This precision can be especially beneficial in patients with complex anatomy or deformity. Robotic assistance also tends to reduce intraoperative radiation exposure for the surgeon and staff by minimizing reliance on repeated fluoroscopic checks. Some clinical series further suggest reductions in surgical revision rates, infection rates, and length of hospital stay, along with the facilitation of minimally invasive approaches when placing hardware percutaneously [55,56].
Despite these advantages, robotic spine surgery has notable limitations. The high upfront cost of robotic systems, including acquisition, maintenance, and disposables, remains a major barrier to widespread adoption. Additionally, robotics requires a steep learning curve and can initially lead to longer operative setup and surgical times, particularly as teams familiarize themselves with registration, calibration, and workflow integration. Technical issues, such as registration errors, skiving, or equipment malfunction, may compromise screw placement accuracy if not properly recognized and managed. Furthermore, because robotic surgery inherently relies on a navigation system, while radiation exposure to the surgeon is minimal, the patient may be exposed to a higher radiation dose. Clinical evidence demonstrating clear, long-term patient outcome superiority, beyond screw placement metrics, remains limited, which challenges the cost-effectiveness justification in some settings.
Future Directions
Emerging trends in MISS suggest that future advancements will hinge on technological innovation and improvements in training paradigms. While image-guided navigation and robotic assistance have already demonstrated enhanced accuracy in pedicle screw placement and reduced radiation exposure compared with traditional techniques, the current high cost of these systems remains a barrier to widespread adoption. Cost reduction and streamlined integration with existing surgical workflows will be critical for broader clinical implementation [56,57]. Concurrently, the steep learning curve inherent to MISS underscores the need for structured education and simulation platforms, including virtual reality, physical models, and hybrid training protocols, that have shown promise in accelerating skill acquisition and reducing procedure-related errors [58]. Addressing procedure-specific complications, such as incomplete decompression and neural injury, will require more sophisticated intraoperative feedback systems and decision support tools to optimize outcomes while preserving the benefits of minimal access. Continued innovation is likely to yield novel applications of robotics, including robot-assisted endoscopic surgery, robot-enabled laminectomy [59], and decompression platforms, which might offer improved precision and safety in complex spinal pathologies. The integration of artificial intelligence with robotic spine surgery is expected to further enhance procedural efficiency and real-time decision-making, thus expanding the future capabilities of MISS.
Conclusions
MISS has become a central component of modern spine surgery, offering reduced soft tissue disruption, shorter hospitalization, and faster recovery, while achieving clinical outcomes comparable to open procedures. However, its broader adoption is limited by technical complexity, a substantial learning curve, and dependence on advanced imaging, navigation, and robotic technologies that impose additional economic and workflow burdens. Continued refinement of techniques, improved cost-effectiveness, and the establishment of standardized training pathways will be essential to enhance the safety, precision, and long-term applicability of MISS in the treatment of various spinal disorders.
Key Points
Minimally invasive spine surgery (MISS) provides comparable clinical and radiographic outcomes to open surgery while minimizing soft tissue disruption across a wide range of spinal conditions.
Technical complexity, limited visualization, and steep learning curves remain major constraints to the broader application of MISS.
Future progress of MISS will rely on cost-efficient technological integration and the incorporation of artificial intelligence–enhanced robotic systems to improve precision and workflow efficiency.
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