In the past decade Spine surgery has witnessed exponential growth in techniques and technologies. Numerous patients have been benefited so far with spinal surgery. With growing experience and growing periods of follow-ups after conventional spine surgeries, surgeons started to face the flip side of these conventional open surgeries. Conventional surgeries have yielded results in many patients but have also left many patients with dissatisfaction with.
Origin of Concept of Minimally Invasive Spine Surgery:
Conventional spinal surgery aims at thorough decompression, rigid stabilization and fusion. These objectives are achieved with large incisions, extensive soft tissue dissection, laminectomies etc. These approach leads to a plethora of untoward effects like..
- Larger blood loss during surgery
- Delayed post-operative recuperation
- Increased hospital stay
- Delayed return to functional status
- Extensive scar tissue formation at operated area and into the epidural space. ( which may cause neural compression )
All these have given rise to a very large group of patients termed as “FAILED BACKs “. Not only do these failed back patients cast a shadow on spinal surgeries but it is not easy to revise these surgeries and produce excellent results.
This forced spinal surgical community to from physiologically devastating conventional surgery to a more friendly and less invasive surgical techniques called “Minimally Invasive Spine Surgery”
Concept of Minimally Invasive Spine Surgery:
MISS are developed with a concept to make surgery as near physiological as possible. The aims are:
- Preserve as much normal tissue as possible
- Eradicate the pathology with least possible damage to normal biomechanical physiology.
- Improve and expedite the post-operative rehabilitation
- Reduce the occurrence of some of the untoward effects of conventional open surgeries like fibrosis and scarring that may cause nerve compression.
In a nutshell, MISS aims to help a patient to get back to his normal active life with the least possible surgical intervention.
Minimally Invasive Spine Surgery (MISS):
Approaching the Spine:
- Instead of extensive soft tissue dissection the MISS approach aims to dilate the muscle instead of cutting and stripping the muscles from lamina and spinous process.
- It preserves the spinous process and lamina as much as possible, maintaining the natural barrier to fibrous tissue in-growth.
- Facet and facet joint capsule are spared completely to prevent iatrogenic instability of motion segment.
- For the anterior approach, Mini-Thoracotomy and Mini-open retroperitoneal approaches have been employed to reduce postoperative approach related morbidity.
Minimally Invasive Disc surgeries:
For many years laminectomy and discectomy have been replaced by Microdiscectomies for cervical and lumbar disc herniations in a stable motion segment. However, microdiscectomy requires epidural dissection, coagulation of epidural blood vessels, nerve retraction, minimal muscle stripping and ligamentum flavum resection.
To avoid all the above surgical violations of normal tissue, discectomies are now done via an endoscopic approach. PELD (percutaneous endoscopic lumbar discectomy)/ PECD (percutaneous endoscopic cervical discectomies) are done through a posterolateral transforaminal approach for lumbar spine and anterior approach for cervical spine. They are done under local anesthesia avoiding the morbidity and risks associated with general anesthesia. To approach the Kambin’s Safe Zone in the transforaminal approach, muscles are dilated upto just 8mm. There is negligible surgical violation of the epidural space around the spinal nerves. The patient can walkout of the operating room. The surgery is done on a day care bases.
Motion Preservation surgeries:
Fusion surgeries have been the gold standard surgical technique for the unstable spine and for multiple degenerated disc disease. Fusion has its own disadvantages like extensive surgical dissection, blood loss, possibility of pseudo-arthrosis and adjacent segment disease. To avoid these complications, MISS attempts to preserve the mobility of a motion-segment. This is done either by using a total cervical/lumbar disc replacement or by using the posterior interspinous stabilizing deveices. Cervical disc replacement has already proven itself in yielding benefits to patients as compared to ACDF (anterior cervical discectomy and fusion). Lumbar disc replacement is still in its very early stage and we need to wait till it really proves itself. Surgeons, infact, are gathering follow-up and improvising the facet joint replacement.
Interspinous devices, basically work by restoring the posterior tension band of a motion-segment, have already been successful in degenerated motion-segment. There are a number of inter-spinous devices available like X-Stop, DIAM, Coflex, Wallis etc. They are useful to offload the degenerated disc, to widen the foramen by keeping the segment in slight flexion, to off-load the facets by being a load-sharing device biomechanically while at the same time providing a restricted safe motion to a segment.
DIAM
Minimally Invasive Fusion Surgeries:
There are multiple pathologies of the spine that can only be treated by a rigid stabilization and fusion like spinal trauma, lytic or dysplastic lysthesis, infection, tumor, etc. When fusion is the only option, minimally invasive fusion is the bridge that least can avoid approach related deleterious effects on a human spine.
In Minimally Invasive fusion surgeries, the spine is approached with a muscle friendly approach as described. Instead of doing a wide decompression, microdecompression is attempted to preserve the natural barrier. Instead of opening very widely for pedicle screw insertion, the screws are placed percutaneously from separate stab incisions. Screws are connected with a rod that is also inserted percutaneously from separate stab incisions. This technique not only preserves a healthy muscle cover but also reduces the blood loss during surgery making patients recover faster.
Minimally Invasive Surgery for Fractures of Spine:
Most spinal fractures require decompression and stabilization by anterior and/or posterior approach. Posterior stabilization now can be achieved by using percutaneous screws. With percutaneous screws, posterior stabilization can be achieved through a stab incision without any damage to soft tissue or without significant blood loss.
In cases of compression fractures that may be traumatic, osteoporotic or pathological, surgeons now performs either vertebroplasty or balloon kyphoplasty keeping minimally invasive concept in mind. Balloon kyphoplasty has some advantages over more commonly performed vertebroplasty. By using Balloon kyphoplasty we can restore the height of compressed vertebra to an extent. kypoplasty reduces the chances of cement leak and also reduces the incidence of adjacent level fracture post procedure.
Advantages of MISS:
- Less tissue trauma
- Less blood loss
- Preservation of physiologically important normal structures
- Rapid postoperative recuperation
- Decreased hospital stay
- Early return to normal functional status
- Decreased incidence of failed back surgeries
- Increased patient satisfaction
Conclusion:
Minimally invasive spinal surgery is in its infancy. With further advances in optics and surgical technologies more and more spinal pathologies will be treated with the MIS concept thereby increasing patients’ satisfaction and also the success rate of spinal surgeries. MISS done so far has immensely benefited patients and has actually reduced some of the untoward effects of conventional open surgery.
Thursday, February 26, 2009
Vertebroplasty and kyphoplasty for osteoporotic fractures
Pin-Hole surgical treatment for vertebral body compression fracture with Vertebroplasty / Balloon Kyphoplasty:
Vertebral body compression fractures (VCFs)- fractures of weakened vertebral body resulting from trivial trauma/loading during normal daily activities- are extremely common amongst the patients with osteoporosis. Osteoporosis is a systemic skeletal disease characterized by compromised bone strength due to the damage to the normal architecture of the bone. Amongst many causes of the osteroporosis senile osteoporosis ( due to older age) and osteoporosis secondary to menopause ( loss of hormonal support) constitutes largest groups of patients suffering from osteoporosis. These are the patients whom we commonly found in our day to day practice presenting with VCFs. VCFs are also found in patients with any disease that weakens vertebral body as in patients with cancers.
In other words, VCFs are commonly found in older age group ( >60 years). It is much more common in elderly females. Almost 25% of female may suffer from VCFs between 60 to 80 years of age. Risck is doubled to 50% beyond 80 years.
VCFs are also found in young population with unaccustomed loading of spine and presents as acute traumatic compression fracture.
The treatment of VCFs is challenging for a medical professional considering the limited options available, particularly for elderly fragile patients. Medical management of these VCFs consists of bed rest, bracing, anti-osteoporotic bone strengthening medications etc. In elderly patients these non-surgical treatment carries risk of multiple complications, which may be potentially life threatening in some cases, like stroke, lung complications, heart complication, adjacent fractures etc. Over and above it propagates the cascade that further weakens the bone due to disuse osteoporosis and may result into fracture elsewhere in the body. Pain arising from these VCFs can be potentially debilitating and may require surgical intervention to provide a quality life in this age group of patients.
Surgical Management is another challenge in geriatric terminally ill patients as they may not tolerate extensive open surgeries and may succumb to surgically induced trauma to body. So the million dollar question is …
“WHAT SHOULD BE DONE? HOW TO TREAT SUCH PATIENTS?”
Minimally Invasive pin-hole vertebroplasty or kyphoplasty can be an answer to this delicate clinical problem. Both surgical procedures have been shown to improve the acute pain and disability associated with VCFs without increasing morbidity of the patient. Balloon kyphoplasty and vertebroplasty are well accepted treatments for VCFs.
First performed in 1984, Vertebroplasty involves injection of bone cement into fractured vertebral body via pedicle as shown in figure. The procedure is performed through a pin hole approach under local anesthesia. The procedure can be a day care surgical intervention wherein patient can get relief of symptoms soon after procedure and may be mobilized and discharged after a few hours of surgery.
First performed in 1998, Balloon kyphoplasty involves percutaneous cannulation of the fractured vertebral body, inflation of the bone tamp (Balloon) inside the vertebral body , and the placement of the cement in the void created by the tamp. It is also performed under local anesthesia through a pin hole approach and can be a day care procedure.
Bone vertebral body augmentation procedure results in stabilization of the VCFs resulting into symptomatic relief. Balloon kyphoplasty differs from vertebroplasty in that tools used to perform kyphoplasty are specifically designed to achieve correction of fracture-related angular deformity and restoration of the lost body height.
An immediate outcome for a patient is more or less same with either procedure. There are no conclusive eveidence to show a clear superiority of a procedure over another. However, studies have shown that the risk of subsequent fracture of the adjacent or non-adjacent verterbral body is greatly reduced with kyphoplasty. This is because kyphoplasty by correcting the deformity and restoring the height , restores the normal bio-mechanics of human spine. Kyphoplasty also helps to inject higher quantity of cement. Higher the cement inside the vertebral body better the stability.
Role of Vertebroplasty/kyphoplasty in acute traumatic burst-compression fracture:
Patients presenting with stable burst fractures or acute traumatic compression fractures without neurological compromise do not need conventional extensive open surgeries. Largely they are treated non-operatively with bed rest, corsets and medications. Pain or disability arising from these fractures may warrants for a surgical intervention in order to restore a patient’s normal functionality. In such patient vertebroplasty/ Kyophoplasty with or without percutaneous screw stabilization could be a truly non-invasive pin-hole surgery.
Conclusion:
Vertebroplasty and kyphoplasty could be a ready and effective minimally invasive option for patients with Vertebral compression fractures in patients who needs to be cured with least invasive measures to avoid morbidity.
Vertebral body compression fractures (VCFs)- fractures of weakened vertebral body resulting from trivial trauma/loading during normal daily activities- are extremely common amongst the patients with osteoporosis. Osteoporosis is a systemic skeletal disease characterized by compromised bone strength due to the damage to the normal architecture of the bone. Amongst many causes of the osteroporosis senile osteoporosis ( due to older age) and osteoporosis secondary to menopause ( loss of hormonal support) constitutes largest groups of patients suffering from osteoporosis. These are the patients whom we commonly found in our day to day practice presenting with VCFs. VCFs are also found in patients with any disease that weakens vertebral body as in patients with cancers.
In other words, VCFs are commonly found in older age group ( >60 years). It is much more common in elderly females. Almost 25% of female may suffer from VCFs between 60 to 80 years of age. Risck is doubled to 50% beyond 80 years.
VCFs are also found in young population with unaccustomed loading of spine and presents as acute traumatic compression fracture.
The treatment of VCFs is challenging for a medical professional considering the limited options available, particularly for elderly fragile patients. Medical management of these VCFs consists of bed rest, bracing, anti-osteoporotic bone strengthening medications etc. In elderly patients these non-surgical treatment carries risk of multiple complications, which may be potentially life threatening in some cases, like stroke, lung complications, heart complication, adjacent fractures etc. Over and above it propagates the cascade that further weakens the bone due to disuse osteoporosis and may result into fracture elsewhere in the body. Pain arising from these VCFs can be potentially debilitating and may require surgical intervention to provide a quality life in this age group of patients.
Surgical Management is another challenge in geriatric terminally ill patients as they may not tolerate extensive open surgeries and may succumb to surgically induced trauma to body. So the million dollar question is …
“WHAT SHOULD BE DONE? HOW TO TREAT SUCH PATIENTS?”
Minimally Invasive pin-hole vertebroplasty or kyphoplasty can be an answer to this delicate clinical problem. Both surgical procedures have been shown to improve the acute pain and disability associated with VCFs without increasing morbidity of the patient. Balloon kyphoplasty and vertebroplasty are well accepted treatments for VCFs.
First performed in 1984, Vertebroplasty involves injection of bone cement into fractured vertebral body via pedicle as shown in figure. The procedure is performed through a pin hole approach under local anesthesia. The procedure can be a day care surgical intervention wherein patient can get relief of symptoms soon after procedure and may be mobilized and discharged after a few hours of surgery.
First performed in 1998, Balloon kyphoplasty involves percutaneous cannulation of the fractured vertebral body, inflation of the bone tamp (Balloon) inside the vertebral body , and the placement of the cement in the void created by the tamp. It is also performed under local anesthesia through a pin hole approach and can be a day care procedure.
Bone vertebral body augmentation procedure results in stabilization of the VCFs resulting into symptomatic relief. Balloon kyphoplasty differs from vertebroplasty in that tools used to perform kyphoplasty are specifically designed to achieve correction of fracture-related angular deformity and restoration of the lost body height.
An immediate outcome for a patient is more or less same with either procedure. There are no conclusive eveidence to show a clear superiority of a procedure over another. However, studies have shown that the risk of subsequent fracture of the adjacent or non-adjacent verterbral body is greatly reduced with kyphoplasty. This is because kyphoplasty by correcting the deformity and restoring the height , restores the normal bio-mechanics of human spine. Kyphoplasty also helps to inject higher quantity of cement. Higher the cement inside the vertebral body better the stability.
Role of Vertebroplasty/kyphoplasty in acute traumatic burst-compression fracture:
Patients presenting with stable burst fractures or acute traumatic compression fractures without neurological compromise do not need conventional extensive open surgeries. Largely they are treated non-operatively with bed rest, corsets and medications. Pain or disability arising from these fractures may warrants for a surgical intervention in order to restore a patient’s normal functionality. In such patient vertebroplasty/ Kyophoplasty with or without percutaneous screw stabilization could be a truly non-invasive pin-hole surgery.
Conclusion:
Vertebroplasty and kyphoplasty could be a ready and effective minimally invasive option for patients with Vertebral compression fractures in patients who needs to be cured with least invasive measures to avoid morbidity.
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