Open spine surgery and minimally invasive approaches

There spinal surgery (spinal column) can be performed using a variety of approaches, ranging from the open surgery to open surgery techniques minimally invasive more recent developments. Historically, spinal surgery was performed through a wide opening: the surgeon made a long midline incision and spread the spine wide apart. muscles to access the vertebrae and discs. This traditional open approach, still widely used, offers excellent visibility of the surgical field and direct access to the spine. However, it inevitably leads to significant muscle damage (detachment or sectioning of the paraspinalis muscles), resulting in post-operative pain and back stiffness during healing. Recovery from open surgery is often longer, due to this muscle trauma and the need to heal detached or severed tissues.

Over the past few decades, technological advances have enabled the development of minimally invasive surgical techniques in order to minimize these open surgery. Two main minimally invasive approaches to the spine have become established: surgery endoscopic and Minimally Invasive Spine Surgery (MISS). In these techniques, small incisions are used and muscles are not cut but simply spread or bypassed, thus reducing tissue trauma. As a result, operative bleeding is reduced, as is the risk of post-operative infection, and patient recovery is generally faster than with a conventional opening. The downside is that these methods require specialized instrumentation (endoscopes, access tubes, intraoperative imaging) and a sometimes lengthy learning curve for the surgeon. Each approach therefore has its advantages and limitations, and the choice between surgery whether open, minimally invasive or endoscopic depends on the pathology to be treated, the patient's anatomy and the surgeon's expertise. Below, we describe these three types of spine surgery - their principles, interests and constraints - before comparing their respective indications.

Endoscopic spine surgery (percutaneous endoscopic technique)

There endoscopic spinal surgery is the technique the most recent and least invasive method of operating on the spinal column. It relies on the use of an endoscope, i.e. a miniaturized camera coupled with surgical micro-instruments, introduced through one or two very small incisions (of the order of 5 to 10 mm each). In practice, the surgeon makes one or two holes («ports») through which he or she inserts the endoscope and the necessary tools (forceps, motorized burrs, coagulation laser, etc.). Thanks to the endoscope's high-definition optics, he can visualize the inside of the column on a screen in real time, with a magnification that enables him to precisely identify the structures to be treated. Under video control, he can perform procedures such as the removal of a herniated disc, the cleaning of a narrow lumbar canal (stenosis) or the resection of small compressive bone fragments, all of which can be performed in a single operation. without opening the back wide.

The advantages of spinal endoscopy lie first and foremost in its ability to extreme minimally invasive. With skin incisions of only a few millimetres, there is virtually no no muscular decay: the muscles are neither detached from the bone nor cut, but simply spread or bypassed by the endoscope tip. This drastically reduces post-operative pain and accelerates functional recovery. What's more, blood loss during the procedure is minimal - often only a few milliliters, the equivalent of a bottle cap - and the risk of infection is very low due to the small size of the surgical wounds. In short, spinal endoscopy enables us to treat certain pathologies while minimizing surgical trauma inflicted on the patient. It can often be performed in outpatient surgery (same-day or next-day hospital discharge), with a much faster return to daily activities than after traditional open surgery. For example, after endoscopic removal of a herniated lumbar discs, patients usually return to a normal life within 1 to 2 days, for light activities, thanks to the accelerated recovery achieved by this technique.

Another significant advantage is the reduced surgical aggression, local anesthesia may sometimes suffice. Indeed, some endoscopic spinal procedures can be performed under spinal anesthesia or light sedation, avoiding the risks associated with general anesthesia in fragile patients. A number of publications report that spinal endoscopy can be used to operate on awake patients or those under local anaesthetic, with a high level of comfort due to the minimal incision and absence of aggressive muscle traction. However, it should be noted that many teams still prefer general anesthesia, even for endoscopy, to ensure total patient immobility and optimal control during delicate procedures. The choice of anaesthetic mode will therefore depend on the type of endoscopic procedure and the preference of the anaesthetist and surgeon.

Here's a summary of the main ones advantages of endoscopic surgery of the spine :

• Minimal incisions and scars: only one or two skin incisions of around 5-10 mm are required, avoiding the long scars of open surgery. The aesthetic impact is limited, and the underlying muscles are preserved.

• Virtually no muscle trauma: Thanks to the endoscope, there's no need to detach or cut the paravertebral muscles. Surrounding tissue is virtually undamaged, resulting in much less post-operative pain and a reduced need for analgesics. The patient recovers mobility faster than after conventional opening.

• Low bleeding and reduced risk of infection: very small openings limit intraoperative blood loss to a few millilitres. Similarly, the risk of wound infection is greatly reduced compared to open surgery, as the surface area exposed to infectious agents is much smaller.

• Short hospital stay and rapid recovery: Most endoscopic spine surgeries are performed on an outpatient basis, or with a short hospital stay (less than 24 hours). Patients can generally be up and about within a few hours of the procedure, and resume their usual activities within a few days, compared with several weeks for equivalent open surgery.

• Light anesthesia possible: in some cases, the procedure can be performed under local anaesthetic (spinal anaesthesia) or sedation, avoiding the need for a heavy general anaesthetic. This can benefit elderly or frail patients by reducing anaesthetic risks and facilitating recovery.

Indications : Endoscopic surgery is particularly indicated for the treatment of the following pathologies localized discs and root canals. For example, endoscopy can be used to effectively remove a herniated disc lumbar or cervical pain responsible for sciatica or brachialgia. It is also used for narrow lumbar canal (spinal stenosis moderate) by nibbling away at the small bony outgrowths and hypertrophied ligaments that compress the nerves. Some forms of spondylolisthesis (vertebral slippage without too much instability) can be relieved endoscopically, by decompressing the compressed nerve roots, although in unstable cases fusion is sometimes necessary. Similarly foraminous conflicts (foraminal hernia) and certain isolated nerve root compressions can be approached endoscopically by precisely targeting the area to be treated. In short, the pathologies ideally treated by endoscopy are those that do not require major reconstruction or fixation (no screws or cages needed). Endoscopy excels in the following procedures decompression nervous The endoscopic approach can also be used to perform targeted surgery without major instability: removal of a hernia, foraminotomy (release of a nerve foramen), resection of a small, benign, accessible tumour, etc. Moreover, by preserving bone and ligament structures as much as possible, the endoscopic approach can sometimes avoid the need for arthrodesis (fusion), which would have been necessary in open surgery to stabilize the spine after extensive dislocation.

Limits : Despite its many advantages, endoscopic spine surgery also has its drawbacks. disadvantages and limitations that you need to be aware of. Firstly, the endoscope's field of vision and action, although optimized by HD cameras, remains than that of a wide opening. The surgeon only has access to a limited portion of the spine through the endoscopic tube, which makes it difficult to perform the surgery. unsuitable for pathologies extensive or complex. For example, in the case of narrow lumbar canal severe multilevel or severe deformity (pronounced scoliosis), the scope of endoscopy is limited - it's difficult to decompress or stabilize everything properly through such small incisions. Similarly, for large spinal tumors or unstable fractures, conventional open surgery is often required to intervene completely and safely. Endoscopic surgery enables fine decompression, but its reduced zone of action may prevent total treatment of severe or multisegmental lumbar pathology. Secondly, handling instruments via the endoscope requires great dexterity and specific training: the learning curve is steep for the surgeon. It takes time and experience to master this technique, and not all spine surgeons are trained in spinal endoscopy, especially as there are still few dedicated training centers. In addition, the high cost of endoscopic equipment (endoscopy tower, special instruments, advanced imaging) may limit its availability in some establishments. Finally, there is a conversion risk intraoperatively: if the endoscopic approach does not resolve the problem (insufficient visualization, bleeding obstructing vision, etc.), the surgeon may have to convert to open surgery during the operation, thereby prolonging the operating time. Fortunately, such conversions are rare when the initial indication is well established.

In short, spinal endoscopy offers the following advantages “great results with small incisions”.”, provided that appropriate cases are selected. It represents a major advance in avoiding the traumas associated with heavy open surgery. However, its use remains limited to situations where targeted decompression is sufficient, and where the surgeon has the necessary expertise. For complex lesions or where extensive fusion is required, other approaches will be preferred. Endoscopy is becoming increasingly popular for moderate disc herniations and stenoses, with efficacy equivalent to conventional techniques for these indications, while reducing operative morbidity. It therefore represents an additional tool in the spine surgical arsenal, complementing - rather than replacing - more conventional approaches.

Minimally invasive spinal surgery (MISS techniques)

There minimally invasive spine surgery (often abbreviated to “MIS” for Minimally Invasive Surgery, or “MISS” for Minimal Invasive Spine Surgery) is a set of techniques designed to accomplish the same goal. objective than open surgery, but through smaller incisions and with reduced tissue trauma. This is sometimes referred to as “percutaneous” surgery or “spinal microsurgery”. The central principle is to’avoid loosening spinal muscles instead of removing the paravertebral muscle mass as in open surgery, we create narrow access corridors between the muscle fibers using special dilators and retractors. The skin is incised minimally (often 15 to 30 mm long, sometimes less), just enough to introduce a tubular retractor. This tube, a few centimetres in diameter, is progressively inserted into the spine, gently pulling the muscles apart without cutting them. It serves as a working tunnel, held in place, through which the surgeon can introduce his or her standard surgical instruments (curettes, forceps, burrs, screws, cages, etc.) to perform the desired operation. While operating, the surgeon visualizes the surgical field, either directly through an operating microscope (microsurgery), or via an endoscopic camera inserted in the tube (micro-endoscopic technique). The aim is identical to that of open surgery (e.g. to remove a hernia, release a nerve, insert screws and fuse vertebrae), but with as little collateral damage as possible.

Visit advantages of minimally invasive surgery (MIS) are well documented:

• Muscle preservation : Unlike conventional opening, which tears or severs the muscles, MIS causes only limited spreading. The paraspinal muscles remain attached to the bone and are simply pulled apart temporarily by the tube, then released at the end of the procedure. This greatly reduces permanent muscle damage. Patients undergoing minimally invasive technique typically suffer from post-operative pain less intense and regain mobility more quickly. In addition, as muscle integrity is better respected, the risk of chronic back pain or post-surgical muscle weakness is reduced compared to equivalent open surgery.

• Reduced skin incision : Although scar size is not the main factor in recovery, it remains much smaller than in open surgery (a few centimetres, as opposed to 10 cm or more in open surgery). This reduction minimizes the wound surface to be healed and reduces the risk of infection of the surgical site. Studies have shown that minimally invasive techniques have on average a lower infection rate than open surgeries, particularly for arthrodesis (spinal fusion) where each limited point of entry reduces exposure to bacteria.

• Less bleeding and general complications: The less aggressive approach preserves muscle vascularity and avoids the need to open up large spaces, resulting in generally lower intraoperative blood loss than with the open technique. This reduces the need for transfusions and the risk of post-operative anaemia. What's more, a smaller incision also means less disruption to physiology: patients operated on by MIS often have a shorter hospital stay and faster functional recovery. For example, after a lumbar fusion Minimally invasive, the average hospital stay is several days shorter than for the same open procedure, and the return to independence is faster thanks to reduced post-operative pain and fatigue.

• Clinical results equivalent to open-label in many indications: For a large number of degenerative pathologies (herniated discs, moderate narrow lumbar canal, low-grade spondylolisthesis, etc.), the literature has shown that minimally invasive surgery offers significant advantages. benefits in terms of morbidity (less pain, less bleeding) without compromising efficiency compared with open surgery. The rates of success, relief of nerve compression and medium-term functional improvement are comparable between MIS and open surgery, provided the technique is well mastered. In other words, the patient enjoys the same clinical benefit (e.g. disappearance of sciatica, (e.g., solid spinal stabilization) while minimizing surgical aggression.

Indications : Minimally invasive techniques can be applied to almost all common surgery of the spine for degenerative purposes. They were initially developed for lumbar disc surgery (nucleotomy, microdiscectomy) and nerve decompression (e.g. partial laminectomy or foraminotomy) where the pathological zone can be easily accessed via a small approach. Gradually, their use has been extended to more complex procedures such as spinal arthrodesis (fusions). For example, it is now possible to perform lumbar arthrodesis using posterior route minimally invasive: the surgeon removes the diseased disc and inserts an interbody cage via a tube, then places percutaneous pedicle screws through separate small incisions, all under radiological guidance. Systems have been designed to screw in the fixation rods without opening the entire back. This type of minimally invasive fusion (sometimes called percutaneous TLIF or PLIF mini-open) treats cases of spondylolisthesis, instability or painful lumbar disc disease, while limiting tissue damage. Similarly lumbar spinal stenosis (narrow canal) can be treated with short bilateral decompression incisions via a unilateral “tubular” approach (inverted “U” technique), which avoids removing too many supporting structures.

Other innovative approaches classified as minimally invasive include anterolateral approaches such as fusion XLIF/OLIF lateral access through the abdomen or psoas, a fusion cage can be inserted without opening the back, thus avoiding damage to the posterior muscles. These lateral techniques further extend the indications for MIS, notably for certain moderate deformities or scoliosis, by enabling multi-level fusion with reduced trauma (no dorsal incision) - even if they entail other neurological risks (psoas nerves) to be monitored. To summarize, most spinal disorders that require surgery can benefit from a minimally invasive approach, If the surgeon considers that he or she can perform the same procedure safely and with reduced access, he or she can use the same technique. Visit herniated lumbar discs are classically treated by microdiscectomy (~3 cm incision) rather than wide open laminectomy. The spinal cord compression (hernia or beak) can be approached via small anterior routes with microscopy. The instrumented mergers for instability from 1 to 3 levels are achievable percutaneously in many situations. However, it is imperative that the the final result obtained is at least equal to that of open surgery The recommendations stipulate that a minimally invasive technique should only be preferred if it offers the same or superior results in terms of decompression and stability. If this is not the case (incomplete decompression, weaker fixation), it is better to opt for a conventional opening from the outset.

Limits and constraints : There minimally invasive spine surgery requires technical expertise pointed and comes with certain constraints. Firstly, the learning curve to master these techniques takes considerably longer than for conventional open surgery. The surgeon must learn to operate in a restricted field, sometimes with indirect vision via a microscope or screens, and manipulating long instruments through a tube. Gestures require great precision, as the margin for error is reduced in a confined space. As a result, the surgeon's experience is crucial Minimally invasive surgery (MIS): poorly controlled minimally invasive surgery can lead to an inferior result, e.g. an unremoved residual disc fragment or a misplaced screw. This is why we believe that effective MIS requires a surgeon specifically trained in these techniques. Secondly, MIS is highly dependent on intraoperative imaging. With small incisions, the surgeon cannot necessarily see all the anatomical landmarks directly. He must use guidance aids such as fluoroscopy (X-ray fluoroscopy) or 3D neuronavigation to confirm the correct placement of instruments and implants. This requires exposure to ionizing radiation for the patient and the team (with each fluoroscopy exposure) is greater than in standard open surgery, where exposure is lower because the anatomy is visualized in the open. This increase in X-ray dose in MIS is a well-recognized disadvantage, requiring precautions (wearing leaded aprons, exposure reduction techniques).

Moreover, although most studies show a reduction in muscular and infectious complications with MIS, possible complications are generally of the same order as for open surgery The difference is that some complications may be more difficult to manage through a small approach. The difference is that some complications may be more difficult to manage through a small approach. For example, controlling venous hemorrhage can be tricky in tubular surgery, requiring conversion to an enlarged opening. Similarly operating time in minimally invasive surgery is sometimes longer than in the classic open technique, at least during the learning curve, as equipment installation and meticulous progression take time. However, with experience and innovations (such as guided implant screws and ready-to-use equipment), the time tends to even out and may even become equivalent to open for certain procedures. Finally, it should be stressed that not all situations lend themselves to MIS for example, in the case of very complex or extensive pathology (severe scoliosis with significant vertebral rotation, malignant tumor invading several structures, extensive infection such as spondylodiscitis with abscess), a minimalist approach may not be sufficient for everything. treat and it is then safer to perform open surgery from the outset, which will allow complete cleaning or stabilization. MIS therefore has its indication limits, An experienced surgeon will know when it is beneficial and when it is inappropriate. In practice, if the pathology requires wide exposure or multi-stage treatment, open surgery still makes sense.

Minimally invasive spinal surgery has established itself as a valuable alternative to traditional open surgery for many conditions. Thanks to innovations such as tubular retractors, 3D imaging, navigation and robotics, it is now possible to reduce surgical morbidity (pain, infection, bleeding), while ensuring success rates comparable to the open approach for many common indications. Nevertheless, it requires adapted infrastructure and specific training, As a result, not all centers yet offer it systematically. The choice between MIS and open surgery must therefore be customized This will depend on the surgeon's training in these techniques, the availability of equipment and, above all, the characteristics of the problem to be treated. As a matter of principle, if MIS enables the same therapeutic result to be achieved with less damage to the patient, it will be preferred. Otherwise, the open approach will remain the reference.

Open spine surgery (conventional “Open” approach)

There open surgery of the spine is the conventional method, practised for decades and still regarded as the “gold standard” in many complex situations. It involves wide exposure of the area to be operated on, through a large skin incision (often of several centimetres), typically centered on the midline of the back opposite the vertebra(s) to be treated. The surgeon cuts or detaches the muscular attachments along the spinous processes and vertebral laminae, then forcefully spread the muscles on either side, using valves or rigid retractors to fully expose the bony architecture of the spine. This open air offers a maximum field of vision All anatomical structures in the area are directly visible, enabling the surgeon to orientate himself easily and work with standard instruments in full light. This broad approach enables the surgeon to perform all necessary procedures - whether removing an intervertebral disc (discectomy), resecting part of a vertebra that compresses the spinal cord (laminectomy), removing a tumour, placing implants (screws, rods) and performing bone fusion, or even correcting a complex deformity by bone osteotomy. Open surgery is therefore very flexible and comprehensive It allows you to single-step treatment of pathologies multi-stage or highly complex, as the surgeon has wide access to the spine and can extend his approach if necessary during the operation.

Visit benefits of the open approach are mainly due to this extended exposure and relative technical simplicity:

• Optimal visualization and direct access: with a wide opening, the surgeon benefits from a unobstructed view on the elements of the spine. For example, during an open decompressive laminectomy, he can simultaneously see both sides of the spinal canal and perform ample decompression of nerve structures. This panoramic view is particularly valuable in anatomically difficult cases - such as severe central stenosis or major deformities -, It makes it easier to understand anatomy and perform complex procedures. In addition, direct access allows him to use normal-sized instruments, palpating structures to assess nerve tension or the strength of a fusion, which is easier than with long instruments in a tube.

• The safest solution for complex cases: For severe, extensive or unstable spinal pathologies, open surgery is often the best option. the safest and most efficient way. For example, a severe scoliosis with vertebral rotation generally requires large incisions to free up several levels, insert long rods and possibly perform osteotomies on the bone; this type of major correction is only achievable through a conventional opening that allows work to be performed on multiple vertebrae at once. Similarly large spinal tumors or invading the spinal canal require wide exposure for safe resection, and widespread infections (spondylodiscitis with abscesses) require complete surgical cleansing, accessible only via an open approach. In these complex situations open surgery ensures freedom total manoeuvrability the surgeon, who can adapt his or her approach during the operation, enlarging the incision if necessary, and thus fully treating the pathology without restriction of field. That's why, as some specialists say, “the most complex cases still often require open surgery” - even in the age of MIS - because it's the method that allows everything to be tackled head-on.

• Standardized, proven procedure: open spine surgery benefits from decades of clinical experience. Open techniques (e.g. arthrodesis posterior open) are mature and widely validated, with well-honed protocols and predictable results. Operating room staff are used to it, and the equipment required is simple (basic instruments, retractors) and available everywhere. There's no need for sophisticated equipment such as neuronavigation or endoscopes - even though these tools can also be used as a complement in open surgery. This robustness of the method means that it is often regarded as a benchmark: when in doubt, the open approach ensures that the intervention can be carried out successfully, because it doesn't depend on a particular technology or a specialized learning curve.

• Conversion facility not required Continuing on from the previous point, in open surgery there is no such thing as a “conversion” situation - since this is already the maximum approach. The surgeon need not worry about running out of access. On the contrary, if he begins a minimally invasive operation and a difficulty arises (insufficient vision, complication), he will have to convert to open to resolve it, which lengthens the operation. By choosing the open option from the outset, we avoid this risk of unplanned conversion. This approach safety that many surgeons prefer to open up difficult cases, in order to anticipate any eventuality and not be limited if a complication arises.

Despite these qualities, it must be emphasized that open surgery has its drawbacks. disadvantages inherent in its invasive nature :

• Increased muscle damage and post-operative pain: Prolonged retraction and dissection of the paraspinalis muscles in open surgery inevitably results in damage to these muscles - contusion, devascularization and even partial necrosis of the fibers. Clinically, this translates into significant post-operative back pain and stiffness, while the muscles heal (a few weeks). This muscular trauma contributes to a longer convalescence: the patient takes longer to regain ease of movement, and requires more powerful analgesics to soothe the pain in the first few days. Sometimes, particularly in frail people, this prolonged pain slows down rehabilitation and can leave sequelae in the form of chronic low-back pain linked to muscle fibrosis.

• Wide incision and more visible scar: A conventional opening often involves a skin incision of 8, 10, 15 cm or more, depending on the extent of the surgery. The resulting scar is more extensive, which can be an aesthetic disadvantage for some patients. But aesthetics aside, a large incision is also a major advantage. wider gateway for infections and takes longer to heal. The risk of surgical site infection is on average higher in open surgery than in minimally invasive surgery (although it remains low overall, ranging from 1 to 5% depending on the series and the type of surgery). Wound care can be more demanding (dressings, monitoring) because of the larger wound.

• Increased blood loss and physiological stress: Opening the joint wide exposes the patient to more extensive bleeding - due to the severing of small muscle vessels and the extent of tissue detachment. It is not uncommon for a multi-level open arthrodesis to be accompanied by bleeding of several hundred millilitres, whereas the minimally invasive equivalent would lose considerably less. This extra bleeding may necessitate transfusions in certain cases of lengthy surgery. In addition, prolonged exposure of the spine during lengthy open surgery can promote hypothermia, tissue dehydration and transient metabolic disturbances (more pronounced inflammatory response). All these factors contribute to slower recovery and an often longer hospital stay than with minimally invasive approaches.

• Delayed convalescence and return to work: As a result of the above, a patient undergoing open surgery will generally require more time before resuming activities normal. For example, after open lumbar fusion surgery, hospitalization is typically 4 to 7 days, followed by several weeks of moderate pain requiring rest and medication. physiotherapy before considering a return to work (sometimes 2 to 3 months for physical work). In contrast, an equivalent minimally invasive fusion may enable the patient to get up more quickly and return to activity in 4 to 6 weeks. The difference can be explained by the slower healing of tissues (muscles, skin) that have been attacked openly, making it necessary to slow initial mobilization so as not to compromise healing.

• Risks to adjacent segments: This point is more subtle, but we suspect that large dissections during open surgery may encourage degeneration of adjacent levels (segments adjacent to the operated area) in the long term. Indeed, muscle and ligament damage can alter local biomechanics and transfer more stress to the upper or lower levels, accelerating their wear and tear. This phenomenon of degeneration of adjacent segments also exists with the fusion itself, but opening wide could exacerbate it. Minimally invasive techniques, by better preserving the supporting structures, hope to reduce this problem, although this is still debated in the literature.

In practice, open surgery remains indispensable in many situations, despite its disadvantages in terms of pain and recovery. It offers universal solution : regardless of type of lesion (degenerative, traumatic, tumoral, deformative), it can still be used if less invasive approaches are unsuitable. In fact, according to international surveys, a majority of surgeons worldwide continue to favor open surgery in cases of degenerative spondylolisthesis with a very narrow lumbar canal, believing it to be the most comprehensive and secure approach to decompressing nerves effectively in these complex scenarios. The surgery The open technique is also the back-up option when minimalist techniques are not sufficient or have failed: for example, if an initial endoscopic decompression proves incomplete, open surgery is required to finish the job. In a way, it constitutes the “maximum ”plan B which guarantees that the surgical objective can be achieved, even if this means paying the price in terms of recovery time. Last but not least, all hospitals with a neurosurgery or spinal orthopedics are able to perform open surgery, while endoscopic or highly specialized approaches are not available everywhere. Open surgery therefore remains the standard reference taught to young spine surgeons, to which we have subsequently added the following minimally invasive techniques according to training opportunities.

Conclusion: Choice of surgical approach and outlook

In a nutshell, three main approaches to spine surgery coexist today: the’spinal endoscopy ultra-minimally invasive surgery conventional minimally invasive (MIS) often tubular, and surgery traditional open. Each has its specific advantages and disadvantages, which we have detailed below. The endoscopic and minimally invasive techniques represent an evolutionary step This is a major innovation aimed at reducing surgical trauma without sacrificing treatment efficacy. They bring undeniable benefits for the patient in terms of post-operative pain, recovery and aesthetics, which explains why they have developed rapidly in recent years. However, they do not do not completely replace open surgery, which remains irreplaceable for the management of complex cases requiring major intervention.

The choice of technique the most appropriate case by case, This is a shared decision between the surgeon and the patient. It depends on several factors pathology (its nature, scope and complexity), the surgical objectives (simple nerve decompression vs. stabilization with implants, deformity correction, etc.), the morphology patient (for example, a patient who is obese or has a history of surgery may complicate certain minimally invasive approaches), as well as the patient's’surgeon expertise and technical resources available in the facility. Ideally, if a center has all the options available, the least invasive approach is preferred as long as it achieves a result as good as that of the open technique.. In many cases of limited degenerative pathology (herniated disc, narrow canal, etc.) spondylolisthesis), minimally invasive or endoscopic surgery provides equivalent results to open surgery with less morbidity, and is therefore recommended as a first-line treatment. On the other hand, for severe cases (multi-stage deformities, major instability, invasive tumors, etc.), open surgery remains the best option because it enables a more complete and safer intervention. According to a publication by the University of Texas, over 90% of spinal pain does not require surgery and can be treated medically, and a large proportion of operable cases can be treated using minimally invasive techniques - the most common form of surgery. only the most complex cases still “require” open surgery. In other words, open surgery is used less and less for common pathologies (which are migrating to MIS/endo), but remains indispensable for extreme situations.

The boundaries between open and minimally invasive procedures are becoming increasingly blurred thanks to new technologies. For example, the 3D navigation, robotic guidance systems, optimized implants and intraoperative imaging now make it possible to extend the indications for MIS to more complex cases than ever before. Multi-level fusions are now performed minimally invasively, with the help of robotics to precisely position numerous screws - something that would have been unimaginable 20 years ago. L’biportal endoscopy (UBE) is an innovation that offers two entry routes instead of one, giving the surgeon triangulation of his or her procedure and the possibility of also treating narrow lumbar canals or migrated hernias, pushing back the limits of traditional endoscopy. These advances make it possible to’apply the principles of minimally invasive surgery for wider and wider, This reduces the need for complete opening. Nevertheless, each new technique has its own learning curve and pitfalls, and none has yet completely supplanted open surgery in all fields.

In conclusion, the spinal surgery “Open” remains the classic approach offering versatility and reliability This is the most effective way of tackling all spinal pathologies, at the cost of greater tissue invasion. In contrast, the endoscopic and minimally invasive have established themselves as less traumatic alternatives for many conditions, with comparable clinical results in well-chosen indications. The modern spine surgeon needs to master the full range of these techniques. techniques to offer each patient the most appropriate, least invasive treatment possible. Visit the watchword is individualized treatment There is no universally superior method, but rather a benefit-risk balance to be assessed for each situation. In 2025 and beyond, the minimally invasive trend is expected to continue, guided by scientific evidence showing improved recoveries, without compromising therapeutic efficacy. However, open surgery retains its value whenever indicated, and remains a core competency, particularly for managing complex cases and intraoperative contingencies. In the end, the important thing is to relieve the patient safety Whether open or minimally invasive, the right approach will be the one that delivers the best clinical outcome with the least risk. The debates between “Open” and “MIS” will no doubt continue to animate the surgical community, but above all they testify to the wealth of options now available for optimizing spinal patient care.

References :

1. IMeD Marseille - Endoscopic spine surgery: a new technique innovative, The advantages of endoscopy (minimal incisions, less pain).

2. Espace Francilien du Rachis (Paris) - Conventional and minimally invasive procedures, The differences between traditional open surgery and minimally invasive surgery (muscle damage) are explained, pain recovery).

3. Dragon Crown Medical - Lumbar surgery: open or minimally invasive? (07/25/2024), details the advantages of minimally invasive endoscopic surgery (incision of a few millimeters, bleeding of a few mL, sufficient local anesthesia, recovery in 24-48h) and its limitations (reduced operating field for complex pathologies).

4. UT Southwestern Medical Center - Back and Spine MedBlog (07/21/2021), confirmation that the majority of back surgeries can be performed minimally invasively, and that only the most complex cases require open surgery, Even then, the aim is to mobilize the patient as quickly as possible.

5. Rachis.paris - Endoscopic lumbar spine surgery, The benefits of endoscopy (less muscle damage, less pain, shorter hospital stay and recovery, greatly reduced risk of infection).

6. A.E. Ropper, Neurospine 2025;22(1):48-50 - Commentary: Open vs MIS in degenerative spondylolisthesis, mention of advances (3D navigation, endoscopy, tubes, robotics, etc.).), enabling fusions to be performed with less soft-tissue damage, less bleeding and shorter hospital stay than with the open technique, and a synthesis of studies showing comparable clinical results between MIS and open fusion, with morbidity benefits in favor of MIS.

7. DeuxièmeAvis.fr - Spinal surgery: what is it? techniques are used? (2024), explains that endoscopy is a minimally invasive technique using ~1 cm incisions, avoiding the muscle trauma of «heavy» open surgery, and reducing post-operative pain and infection.

8. Espace Francilien du Rachis - Interventions conventional vs. minimally invasive, notes that the indications for minimally invasive surgery are the same as for open surgery provided an equivalent result is obtained, If not, conventional techniques should be preferred.

9. S. Schuller & J.-Y. Le Huec - Conference (YouTube, 2021), indicate that the learning curve for endoscopic spinal surgery is long and demanding, with training not yet widespread, making it important to reserve this technique for trained surgeons.

10. Lyon-Charcot Clinic - Spinal endoscopy (2023), mentions that in lumbar spinal endoscopy, general anaesthesia is generally used, as local/spinal anaesthesia would not ensure sufficient patient immobility for delicate procedures. (N.B.: This point illustrates a practical preference, although cases of spinal anaesthesia do exist).

11. Lewandowski et al., J. Spine Surg. 2020;6(Suppl1):S260-74 - International survey on acceptance of MIS: perception of MIS as a “mainstream” treatment is highest in Asia and South America, lowest in Europe and North America, but the actual rate of MIS use by surgeons is higher than perceived, This is a sign of the gradual global adoption of minimally invasive techniques.

12. Dragon Crown Medical - advantages of lumbar fusion open (wider decompression, high stability thanks to arthrodesis, proven technology) and its drawbacks (relatively large surgical incision, long convalescence, risk of degeneration of adjacent segments).