Secondary surgeries were performed for pseudarthrosis repair and for symptomatic adjacent-level degeneration. How to Heal a Herniated Disc Naturally: Know the Truth! This article does not include a complete list of all potential risks and complications: as with all surgeries, it is advisable to fully review the potential risks and complications with the treating surgeon prior to having ACDF surgery. Depending on the location and extent of your surgery, you may experience some pain and discomfort but the pain can usually be controlled well with medications. Adjacent Segment Disease and injury of spinal muscles are additional complications from fusion surgery. Lumbar fusion is a surgical treatment for patients with ongoing pain low back pain or leg pain that has failed conservative treatment. 2013;7:5659. Anterior Cervical Discectomy and Fusion (ACDF) Video, Learn how bone growth stimulation therapy can help your healing process. For procedures that require more bone, like a posterior fusion, the non-union rates are as high as 26-36% (2,3). Office hours: 7am 5pm, Knee Hurts When I Bend It and Straighten It, Burning Pain on Outside of Knee When Kneeling, Muscle Pain After Cervical Fusion Surgery, Basal Joint Arthritis or CMC / Carpometacarpal Arthritis, Common Craniocervical Instability Symptoms, Perc-FSU Trusted Alternative to Spinal Fusion, Perc-ACLR - Regenexx Treatment for ACL Tear, Regenexx Non-Surgical Alternative to Cervical Fusion, Perc-CT SR Alternative to Carpal Tunnel Surgery, Non-surgical Disc Bulge or Herniated Disc Treatment, Regenexx Alternative to Ankle Fusion Surgery, Perc-CMC Alternative to CMC Joint Surgery. Epub 2016 Jun 17. The age, overall health, and physical condition of a patient influence how soon they recuperate and return to their normal activities. 5. The Mayo Clinic indicates you will most likely be in the hospital for 2 to 3 days after surgery 13. PLoS One. The surgeon uses bone grafts or metal implants to attach the . Mayo Clinic does not endorse companies or products. What Are The Long Term Effects of Spinal Fusion? Reoperation rate after instrumented posterior lumbar interbody fusion: a report on 1680 cases, Adjacent Segment Disease After Posterior Lumbar Interbody Fusion: A Case Series of 1000 Patients. Therefore, L5 S1 fusion surgery involves the surgical removal of the L5/S1 disc and fusing the L5 and S1 spinal bones together. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research. Federal government websites often end in .gov or .mil. Abstract To determine the long-term effects of lower lumbar fusion, 94 subjects were catalogued from medical records. The most common risk of any of the modern spine fusion surgery techniques is the failure to relieve lower back pain symptoms following the surgery. Another potential complication of spine fusion surgery in the low back includes any type of nerve damage. PRP is rich in growth factors that can increase blood flow and healing. Rates vary depending upon the specific type of lumbar spinal fusion procedure. There is the possibility that the surgery is not successful in treating the pain and the symptoms return. Patel MR, Jacob KC, Parsons AW, Vanjani NN, Prabhu MC, Pawlowski H, Singh K. Int J Spine Surg. It has been estimated that about of patients will have symptoms from problems at an adjacent disc by 10 years after surgery. The long-term effects of spinal fusion on the sacroiliac joints and ilium Ninety-six patients who had lumbar disk excision and primary posterior fusion were studied 10 or more years after their operations. The disc is an important shock absorber. See if you're a Candidate for Regenexx Back Procedures. Spinal fusion can help address malformations in the spine, such as a lateral curvature (scoliosis). Yes! The results are alarming! eCollection 2022. ", Research has established that the SI joint is the source of pain in nearly half of patients who experience new or continued low back pain after fusion surgery. What are the options to I've developed numbness and tingling in my fingers that gets worse after pushing up hills. Get Veritas Health Newsletters delivered to your inbox. Director of Regenerative Interventional Spine Medicine Screws are used in lumbar fusion to stabilize the spine. Although spinal fusion is a surgical procedure used to stabilize and join two or more vertebrae together, it can still cause issues in the long run. In the example shown, a damaged disk is removed, a bone graft is inserted, and plates and screws hold the bones together. Collectively about 1 in 10 patients who have a low back fusion will need a second surgery to fix non-union or hardware failure (8). Degeneration: One of the most common issues young patients that have spinal fusion is the development of "adjacent level degeneration" which is the breakdown of the. Read More. Stabilization with the Dynamic Cervical Implant: a novel treatment approach following cervical discectomy and decompression. Any use of this site constitutes your agreement to the Terms and Conditions and Privacy Policy linked below. At CELLAXYS, we offer two types of regenerative treatments. In most cases, spinal fusion is a generally safe treatment. Disk replacement is a new type of spine surgery so there is little information on possible long-term risks and outcomes. Obtain Long Term Pain Relief. 2017 May;26(5):577-585. doi: 10.3171/2016.10.SPINE16317. Hardware Longevity and Failure Any medical procedure that depends upon installing foreign and unnatural hardware into the body comes with additional risks and related questions: What type of material is being used? 303-429-6448 Schedule a Telemedicine consult and learn from a board-certified, fellowship-trained physician what options are available. 2018;48(12):1430-4. The SI fusion system follows the principles of arthrodesis: aggressive joint preparation, enhanced compression and stability. Spinal fusion is a major surgery where one or more spinal bones (vertebrae) are fused together using screws, bolts, and or plates. Journal of Spine Surgery. [emailprotected] Before a spinal fusion, it is typically not essential to donate blood. No statements or treatments presented by CellAxys have been evaluated or approved by the Food and Drug Administration (FDA). All rights reserved. Make a donation. This content does not have an Arabic version. The site is secure. What are the indications for L5 S1 Fusion? When surgery is indicated, Mayo Clinic uses a new, minimally invasive SI fusion implant developed by researchers at Mayo Clinic and CoorsTek Medical and approved by the Food and Drug Administration. Fusing usually takes about. 2022; doi:10.23736/S0375-9393.22.15933-X. Some people may have a repeat of their initial symptoms. Learn more about the long-term effects of spinal fusion here. BMC Musculoskelet Disord 21, 73 (2020). Lumbar fusion can be used to treat a number of painful and degenerative conditions in the low back. Resnick, D., Choudhri, T., Daily, A., Groff, M. Khoo, L., Matz, P., Mummaneni, P., Watters, W., Wang, J., Walters, B., Hadley, M. Guidelines for the performance of fusion procedures for degenerative disease of the lumbar spine. Bethesda, MD 20894, Web Policies The recovery period is generally six to eight weeks, with some people experiencing intense pain for several days or more following either the trial period or permanent implantation of the spinal cord stimulation devices. Spinal fusion can be done in the neck, thoracic, and lumbar regions. Implant failure, particularly early after back surgery, is a sign of persistent severe spinal instability. Young adult hip and pelvic conditions: Comprehensive approach for optimal care. All rights reserved. 2014;8(3):281-97. Learn How Bone Growth Therapy Can Help You, Get a Comprehensive Evaluation from Mayo Clinic's Spine Care Experts. In: Schwartz's Principles of Surgery. Following a doctors orders and adhering to post operative instructions are extremely necessary to minimize the risk of complications in the weeks and months following surgery. Injury to blood vessels or nerves in and around the spine. Spinal fusion is generally safe. Allscripts EPSi. Unfortunately, lumbar fusion significantly compromises the health and integrity of these muscles. Your low back pain is crippling and has failed to respond to conservative treatments. Wear your brace as instructed. The patients discharge date is determined by their general health, the physicians procedures, and the patients response to the procedure. Fracture types. Chronic pain causes changes in your brain and nervous system. J Am Acad Orthop Surg Glob Res Rev. You have to employ these principles to achieve durable, long-term outcomes that are going to return patients to a much greater quality of a life.". Brunicardi FC, et al. Are there regenerative alternative treatments? There are several reasons for this. UCLA Alumni. The spinal muscles provide critical stability and support for the spine. They contain 10 Growth Factors to promote healing, send chemical signals to attract cells from the blood, and produce a web-like structure called fibrin to support the development of new tissues. The incidence of hardware failure in one study was an alarming 36% (4). Physical therapy can teach you how to move, sit, stand and walk in a manner that keeps your spine properly aligned. Fusion surgery removes this important shock absorber placing additional stress and forces on the discs and facet joints above and below the level of the fusion. Reisener MJ, et al. You may be asked to stop taking some medicines for a time before the surgery. 1991 Jul; 73(6):802-8. https://www.ncbi.nlm.nih.gov/pubmed/2071615/. Success rates vary depending upon the parameters examined. This occurs when part of the hardware breaks or slips and then impinges on the spinal cord or spinal roots. You may be instructed to wear a back brace for a time specified by your physician. 11th ed. Damage to the spinal cord (about 1 in 10,000) Bleeding, major blood vessel injury. As with any surgery, there are a number of possible risks and complications of anterior cervical discectomy surgery, or ACDF. Spinal fusion connects two or more bones in the spine to make it more stable, correct a problem or reduce pain. A spine surgeon will use more bone, known as a bone graft, to encourage bone fusion. Copyright 2023 Leaf Group Ltd., all rights reserved. Image shows significant SI joint degenerative changes secondary to chronic pelvic instability from pubic symphysis resection 30 years earlier. Twenty-four were not located and 8 were deceased. J Bone Joint Surg Am 1998; 80:941951. 2017 Feb;42(2):E5. Avoid strenuous activities of any kind (golfing, tennis, home improvement tasks, etc.). 2015 Mar;22(3):237-45. doi: 10.3171/2014.10.SPINE131089. The age, overall health, and physical condition of a patient influence how soon they recuperate and return to their normal activities. Robinson anterior cervical discectomy and arthrodesis for cervical radiculopathy. Then the spine might need more surgery in the future. PLIF, posterior lumbar interbody fusion is a case in point that has been reviewed in detail in a prior blog. Outcomes included visual analog scale for neck and arm pain. "The maneuver, what I have termed the Mayo SI test, manipulates the SI joint in such a way that it can cause extreme pain in some patients," Dr. Cross says. J Neurosurg: Spine 2:673678, 2005. https://orthoinfo.aaos.org/en/treatment/spinal-fusion. Patients frequently need to wear a back brace after they leave the hospital to keep their spine in good alignment. 2008;17(8):11071112. Experiencing back pain? This affects patients with large and progressive curves (over 70 degrees) that compress the lungs. You may have acute chest discomfort, shortness of breath, or coughing if this happens. The doctor takes these cells from the patients adipose (fat) tissue and bone marrow. Nerve root damage. The . This content does not have an English version. 6.Okuda S, Yamashita T, Matsumoto T, et al. When they take cells from the adipose tissue, it is called Minimally Manipulated Adipose Tissue (MMAT) transplant. What is a spinal fusion? Following a doctors orders and adhering to post operative instructions are extremely necessary to minimize the risk of complications in the weeks and months following surgery. Unfortunately, years later the pain continues. Spinal fusion: Spinal fusion is typically performed in more severe cases, especially when multiple levels of the spine are involved. Regrettably, as a result of these forces, the hardware can break creating spinal instability and pain. All can require additional surgery. If the damage is permanent, the nerve will not respond to the surgical decompression and your pain will not be relieved. Accessed Nov. 18, 2022. "The imaging can look normal, and the reliability of common physical exam techniques can be poor. Having a spine that doesn't move in places puts more strain on the areas around the fused part. The same forces that can cause the hardware to break can also cause the screws to become loose. The patients discharge date is determined by their general health, the physicians procedures, and the patients response to the procedure. Although major loss of the strength and sensation to the legs or loss of bowel or bladder control can occur, it is rare. Surgeries are often extremely painful and have a very long recovery time. How long will the hardware last? While neck fusion has a good record of eliminating or reducing neck-related arm pain, tingling, and weakness, many patients want to know how much neck mobility might be lost when one or more mobile joints in the neck are fused solidand whether that can impact quality of life. Lumbar spinal stenosis (adult). An important long-term experiment compared spinal fusion to physiotherapy over more than a decade seemed to produce a contradictory result that "prevents a strong conclusion.". Spinal stenosis surgery is a procedure performed to relieve pressure from the spinal cord and/or spinal nerve roots by removing structures from the spine, such as portions of discs, ligaments, and bone. Spine (Phila Pa 1976) 1998; 23:188192. Minerva Anestesiologica. 1. "But with force transfer after spinal fusion, the SI joints can move a couple of millimeters," he says. Office hours: 7am 5pm, Knee Hurts When I Bend It and Straighten It, Burning Pain on Outside of Knee When Kneeling, Muscle Pain After Cervical Fusion Surgery, Basal Joint Arthritis or CMC / Carpometacarpal Arthritis, Common Craniocervical Instability Symptoms, Perc-FSU Trusted Alternative to Spinal Fusion, Perc-ACLR - Regenexx Treatment for ACL Tear, Regenexx Non-Surgical Alternative to Cervical Fusion, Perc-CT SR Alternative to Carpal Tunnel Surgery, Non-surgical Disc Bulge or Herniated Disc Treatment, Regenexx Alternative to Ankle Fusion Surgery, Perc-CMC Alternative to CMC Joint Surgery, Spinal fusion in the United States: analysis of trends from 1998 to 2008, Functional results after anterior lumbar fusion at L5-S1 in patients with normal and abnormal MRI scans, Evaluating rehabilitation following lumbar fusion surgery, Failed back surgery syndrome: definition, epidemiology and demographics, Degenerative lumbar spondylolisthesis with spinal stenosis. [emailprotected] eCollection 2022. J Bone Joint Surg Am. Arthritis causes much of back pain. Metal plates, screws or rods might hold the bones together. The most common causes of a failed lumbar fusion are nonunion, hardware breaking, and hardware becoming loose. A recent study looked at the effects of single-level lumbar fusion on spine muscle health (7). 1991 Jul; 73(6):802-8. https://www.ncbi.nlm.nih.gov/pubmed/2071615/. The surgery involves cutting through important muscles, ligaments, and tendons to access the targeted disc. Impact of Gender on Postsurgical Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion. Unfortunately, after the surgery, the pain never changed. Unlike a microdiscectomy for treatment of a lumbar disc herniation, with an ACDF there is little chance of a recurrent disc herniation because the disc is removed. ACDF is a proven treatment for patients with stenosis and disc herniation and results in significantly improved short- and intermediate-term outcomes. A blood clot can move through the circulation and end up in the lungs on rare occasions. Lumbar transpedicular implant failure: a clinical and surgical challenge and its radiological assessment. If your low back pain persists despite conservative care know that you have regenerative options. Because there are a significant number of variables involved including the specific surgical approach, preoperative MRI, and x-ray finding, the results from pressuring the disc, patients age, medical history, and the parameters studied. 2022 Oct 17;9:983931. doi: 10.3389/fsurg.2022.983931. eCollection 2016. As a result, spinal hardware might be utilized as an internal splint to keep the spine in place as it heals following surgery. doi: 10.3171/2016.11.FOCUS16412. Asian Spine J. "The SI joint is often glossed over as a pain generator, especially in people who have had spinal fusion and experience continued pain," says William W. Cross III, M.D., an orthopedic surgeon at Mayo Clinic in Rochester, Minnesota. In addition, nerve damage is a rare, but possible long term effect of having a spinal fusion 13. Those changes can make pain feel more severe (hyperalgesia) or cause your nervous system to send pain signals for things that shouldn't hurt (allodynia). The most common include failed fusion where the bones do not properly fuse. Accessed Nov. 22, 2022. I am a co-founder of the Centeno-Schultz Clinic which was established in 2005. Poor wound healing. Unable to load your collection due to an error, Unable to load your delegates due to an error. Klein GR, Vaccaro AR, Albert TJ. A prospective study comparing decompression with decompression and intertransverse process arthrodesis. The esophagus lies directly in front of the spine and needs to be mobilized and retracted during surgery, which can cause difficulty swallowing. "We have seen patients ranging in age from their mid-30s to their 80s who have had degenerative changes in the SI joint after spinal fusion," Dr. Cross says. A surgeon can get to the spine from the front, known as an anterior spinal fusion. Spine (Phila Pa 1976) 2012;37:6776. But as with any surgery, spinal fusion carries some risks. PRP and cell-based therapies are promising options for lumbar disc replacement and spinal fusion. Over the long term, additional surgery for pseudarthrosis (10%) occurred in the early follow-up period, and for adjacent segment degeneration (21%), which occurred linearly during the >10-year follow-up period. AskMayoExpert. What are the long-term side effects of spinal fusion? A single copy of these materials may be reprinted for noncommercial personal use only. Is Minimally Invasive Spine Surgery Right for You? Platelets are the bodys first line of defense against injuries. This additional force in turn can lead to injury of these facet joints and discs leading to degeneration and arthritis. This approach is a successful, natural alternative to back surgery without the complications outlined above. For procedures that require more bone, like a posterior fusion, the non-union rates are as high as 26-36% (5,6,). This site is for educational purposes only; no information is intended or implied to be a substitute for professional medical advice. Medical implants come in a variety of forms, sizes, and styles all of which are meant to treat spinal diseases in individuals of all ages. It is still unknown whether having a fusion surgery, with the resulting loss of motion between the vertebrae, contributes to the faster disc degeneration above and below the fusion. Part 8: lumbar fusion for disc herniation and radiculopathy. NCI CPTC Antibody Characterization Program. Either way, a metal plate or rods and screws will hold the bones together until the bones heal. Salamanna F, Contartese D, Tschon M, Borsari V, Griffoni C, Gasbarrini A, Fini M. Front Surg. Loss of height (stature). For example, fusion may cause adjacent vertebrae to become less stable, resulting in further pain and discomfort. A. Before 2020; doi:10.21037/jss-20-492. Created for people with ongoing healthcare needs but benefits everyone. The rate of occurrence of potential risks and complications is variable and dependent mainly on a combination of the following factors: See Quitting Smoking Before a Spinal Fusion. As a result, spinal hardware might be utilized as an internal splint to keep the spine in place as it heals following surgery. Absolutely. This additional force in turn can lead to injury of these facet joints and discs leading to degeneration and arthritis. Get Veritas Health Newsletters delivered to your inbox. This content does not have an English version. This site complies with the HONcode standard for trustworthy health information: verify here. A blood clot can move through the circulation and end up in the lungs on rare occasions. Rajakumar DV, Hari A, Krishna M, Konar S, Sharma A. Neurosurg Focus. Bookshelf Singleton M, et al. Health outcome assessment before and after anterior cervical discectomy and fusion for radiculopathy: a prospective analysis. The most common indications for L5 S1 fusion include: Low back disc degeneration Slipped disc ( spondylolisthesis) Spinal Bone Fracture Recurrent Disc Herniation Pain radiating down leg (Sciatica ) Curvature (Scoliosis) Narrowing of the Canal (Stenosis) Failed Spine Surgery with Instability. There is also a chance of developing symptoms at of the disc levels either above or below the fused vertebrae, termed Adjacent Segment Disease (ASD). For all diagnostic groups, significant outcomes improvement was seen at all follow-up periods for all scales relative to preoperative scores. 1.Deyo RA, Gray DT, Kreuter W, Mirza S, Martin BI. HHS Vulnerability Disclosure, Help But study results are mixed when the cause of the back or neck pain is unclear. PMC Spine. Patients must stay in the hospital for a period of recuperation and supervision following a spinal fusion. The device entered clinical use in late 2017. Pain at the bone graft site. Long-term follow-up of one hundred and twenty-two patients. doi: 10.1371/journal.pone.0149312. "However, if the steroid doesn't work and SI fusion is anticipated, we wait three months because of the potential increased risk of infection with steroid use.". The production of blood clots in the legs is another unusual consequence. Patients are taught new methods to move after surgery since their flexibility may be reduced. This procedure is called anterior diskectomy and fusion. While the bone graft sets, metal plates, rods, or screws may be used to keep the vertebrae together. A. The image on the left is after the surgery. Thomson S. Failed back surgery syndrome: definition, epidemiology and demographics. Please enable it to take advantage of the complete set of features! These treatments are non-invasive and less painful than conventional methods. The https:// ensures that you are connecting to the 4. The AAOS indicates that physical activity too soon after surgery can result in pseudarthrosis, which may prompt a second surgery 13. Full recovery from spinal fusion surgery can take between six months to a year to resume normal activities. If there isnt enough support to hold the spine as it fuses, an instrumented fusion might fail. If the anterior devices were placed anteriorly (from the front), rather than through a. Br J Pain. Injury to blood vessels or nerves in and around the spine. There is a small plexus of nerves in front of the L5-S1 disc space that helps control ejaculation. I have been a patient with severe pain and know firsthand the limitations of traditional orthopedic surgery. If these nerves are affected (which can happen 1% of the time) then a valve will not close that forces the ejaculate outward. Obtain Long Term Pain Relief. Treatment options include PRP and your own bone marrow-derived stem cells. In a small percentage of men who have an anterior fusion, an infrequent complication results in difficulties with ejaculation following spine fusion surgery. Medical implants come in a variety of forms, sizes, and styles all of which are meant to treat spinal diseases in individuals of all ages. Some patients with this ailment have no symptoms, while others have back, neck, arm, or leg discomfort. J Bone Joint Surg Am 1993; 75:12981307. (2) 2 years after lumbar fusion 40% of patients were unsure/dissatisfied with the outcomes reporting ongoing back pain and limited daily function (3) Another study demonstrated that the overall failure rate of lumbar spine surgery was estimated to be 10%46% (4). VA underwent lumbar fusion several years ago for severe low back pain. If they break off and migrate to the lungs, they represent a serious threat. The most common types of spinal fractures include: Compression fractures: Compression fractures are small breaks or cracks in your vertebrae that are caused by traumas or develop over time as a result of osteoporosis. Regrettably, as a result of these forces, the hardware can break creating spinal instability and pain. Some potential risks of cervical spine surgery include: Reactions to the anesthesia . Absolutely! To assess the long-term, >10-year clinical outcomes of anterior cervical discectomy and fusion (ACDF) and to compare outcomes based on primary diagnosis of disc herniation, stenosis or advanced degenerative disc disease (DDD), number of levels treated, and preexisting adjacent level degeneration. The functional spinal unit is the comprehensive approach utilized at The Centeno-Schultz Clinic, in Broomfield, Colorado right between Boulder and Denver. Trends in lumbar spinal fusion A literature review. To assess the long-term, >10-year clinical outcomes of anterior cervical discectomy and fusion (ACDF) and to compare outcomes based on primary diagnosis of disc herniation, stenosis or advanced degenerative disc disease (DDD), number of levels treated, and preexisting adjacent level degeneration. From the back, it's known as posterior spinal fusion. The disc is an important shock absorber. I quit a successful career in anesthesia and traditional pain management to pursue and advance the use of PRP and bone marrow concentrate for common orthopedic conditions. Kwon B, Kim DH, Marvin A, et al. https://www.uptodate.com/contents/search. Possible complications include: Infection. Why would a lumbar fusion fail? Smoking, diabetes, and advanced age can also increase the risk of developing pseudarthrosis. Thirty-seven per cent complained of persistent graft donor site pain. His low back MRI is below and is most significant for the death of the critical low back muscles. By far the most common complication following surgery is difficulty with swallowing, medically known as dysphagia. Absolutely. Infection. What is the success rate of fusion surgery? Spinal fusion often works no better than nonsurgical treatments for back pain with a cause that's not clear. But traditional open anterior or posterior surgery requires extensive soft tissue dissection to expose the anatomic landmarks for screw insertion, achieve a proper screw trajectory and develop an . Only after your doctor can establish the source of your discomfort will they offer spinal fusion surgery. Anterior cervical decompression and arthrodesis for the treatment of cervical spondylotic myelopathy. This lasts 3-4 days on average. Premature feeling of fullness in the stomach (hunger satiety). Anterior surgical treatment for cervical degenerative radiculopathy: a prediction model for non-success. Spinal instrumentation, also known as spinal implants, devices, or hardware, involves the implantation of stainless steel, titanium, titanium alloy, or non-metallic items into the spine by surgical procedures. What causes spinal fusion to fail? 1. The long-term side effects of spinal fusion involve non-union, hardware failure, Adjacent Segment Disease, and spinal muscle injury. There are many reasons for this to occur. Epub 2022 Dec 8. Results: These treatments are used to restore spine stability, cure spinal deformity (such as scoliosis), and bridge space produced after a spinal decompression procedure by removing a spinal part. Methods: 2008;17(8):11071112. Paraspinal muscle changes after single-level posterior lumbar fusion: volumetric analyses and literature review. An official website of the United States government. Consider the following results: In one study 53 patients were followed for an average of 20 months after fusion surgery. Lumbar fusion involves screws, bolts, and plates that stabilize the spinal bones. These synthetic materials aid to increase bone development and accelerating vertebral fusion. On the right, the yellow arrows point to dark healthy spine muscles that were present prior to the surgery. 2023 Jan;165(1):145-157. doi: 10.1007/s00701-022-05440-2.