I have a failed fusion L3/4/5 with loose screws. I'm not in much pain. The doctors say I should have a revision, AP with rods/screws/and BAK cages. That's 3 opinions.

They'd all do it the same, open the back, remove hardware; flip me over and put in cages; flip me over, open back again and put in new screws.

But I've just read a review article sent me by a spiney which says that the hardest part of fusion is surgery from the back. It is incredibly disuptive of the long muscles, denervates them and may denervate facets. Lots of fibrosis can occur. In the end, it's a crapshoot whether the patient ends up with a lot of pain from having their back manipulated so much.

However, two articles I've read explain taking out hardware using minimally invasive surgery.

Many many articles use translaminar facet screws, rather than rods and screws, and the results appear to be better.

Does anyone have any experience with either of these or know anyone who has? Also, does anyone have any suggestions where else I might post to find people with experience with this?

For anyone interested, here are the key paragraphs from teh review article:


Posterior Pedicle Screws

Stand–alone pedicular instrumentation has increased the fusion rate in degenerative lumbar conditions (40,41,42). Zdeblick (10) showed, in a well–conceived prospective, randomized study, that a rigid pedicle screw/rod construct statistically significantly increased the fusion rate (95%) of degenerative lumbar conditions compared with noninstrumented (65%) or a semirigid pedicle screw/plate construct (77%). Unfortunately, simply exposing the posterior lumbar spine can result in profound paraspinal muscle damage with postoperative muscle fibrosis, as well as muscle and facet joint denervation. This "posterior fusion disease" causes severe damage to the posterior spinal musculature, not only by the direct dissection but also by the denervation that must inevitably occur as the result of the destruction of its nerve supply during the exposure.

Posterior lumbar muscles are injured after posterior lumbar spine surgery, as demonstrated by findings on histology, computed tomography, and magnetic resonance imaging. Mayer (43) found weakness in paraspinal muscle strength with atrophy detected by measuring cross–sectional area and density on postoperative CT scans 3 months after posterior lumbar surgery. These pathologic changes likely contribute to poor clinical outcome. Alterations in electromyographic activity have been documented up to 4 years after surgery (44). Macnab (45) reported that denervation of paravertebral muscles occurred in 96% of 113 patients who underwent posterior lumbar surgery based on results of an electromyographic study. Denervation potentials were demonstrated within 1 year after surgery. Degeneration of the back muscle occurs just after surgery and the muscle in most reoperated patients shows severe histologic damage, including denervation, reinnervation, and early aging. Sihvonen (46) demonstrated CT and EMG abnormalities and correlated these with postoperative failed back syndrome.

External compression by a retractor increases the intramuscular pressure and decreases local muscle blood flow. The pathologic condition of the back muscle beneath the retractor blade is similar to that of skeletal muscle beneath a tourniquet. Metabolic changes and microvascular abnormalities occur. A pathogenic mechanism for the muscle injury is based on compression and ischemia of the affected muscle. Two hours of continuous retraction caused significant histologic changes and neurogenic damage including degeneration of the neuromuscular junction and atrophy of the muscle (47). In an animal model, muscle injury after surgery was related to the retraction time and the pressure load generated by the retractor4a. Posterior surgical intervention to the lumbar spine always produces a risk of back muscle injury. Degeneration of the multifidus muscle (49) was found after surgery and human back muscle in patients who underwent repeat surgery showed severe neurogenic damage (50). This muscle injury after posterior surgery might cause postoperative low back pain and compromise the functional integrity of the muscle (51). Rantanen et al (51) also found selective type 2 muscle fiber atrophy and pathologic structural changes in the back muscles of the patients who had severe handicap after posterior lumbar surgery. The medial branch of the dorsal primary ramus, which courses around the superior articular process, innervates the muitifidus. The medial branch sits in a groove between the mammary process and the accessory process, and retraction of the multifidus lateral to the midpoint of the facet joint stretches the nerve. This dorsal (posterior) ramus is damaged by posterior lumbar procedures (52). The nerve root has no perineurium and is only covered by a thin root sheath (53). Moreover, the nerve root has a poorly developed vascular network54 compared to peripheral nerves; thus nerve root compression induces structural change more readily than occurs with peripheral nerve.

Furthermore, posterior lumbar fusions have been associated with an increased incidence of adjacent level degeneration (transitional syndrome). Lehmann55 reported a 30% rate of stenosis above a posterior fusion with an average follow–up of 21 years. Aota (56) found a 25% incidence of postfusion instability after posterior pedicle screw fusion with Cotrel–Dubousset instrumentation in 65 patients with lumbar degenerative disorders. Conversely, an ALIF procedure does not significantly alter the rate of development of adjacent level degenerative changes over that of natural history (57). Fraser (57) found better outcomes are obtained after anterior interbody fusion than after posterolateral fusion with internal fixation, despite a higher fusion rate in the latter group. Late spinal stenosis adjacent to a fusion is more likely to occur with posterior fusion procedures than with anterior fusion alone. A posterolateral fusion carries the distinct disadvantage of causing damage to important stabilizing muscles and damage to the nerve supply of these muscles, in itself a possible mechanism for continuing pain and loss of function. In one study with 16–year follow–up after ALIF, the rate of adjacent level degenerative changes was similar to an age–matched control population (58). Luk et al. (59) found no increased compensatory motion in the transition zone immediately above an ALIF. Penta et al. (60) concluded that the rate of degenerative changes adjacent to an ALIF at 10 years, as assessed by MRI, was not significantly increased.



Translaminar screws: READ



Devised by Magerl,(95) this technique requires a small incision with dissection only out to the facet joints. The transverse processes and cephalad juxtalevel facet joints are not exposed. Clinical studies have reported a high success rate with minimal complications (96,97,98,99). Magerl's technique is a modification of Boucher, which is a modification of King's description of facet joint screws. King'(100) in 1948 reported his operation whereby short screws are placed horizontally directly across the facet joint. The screw enters the inferior articular process just medial to the joint and crosses the joint into the ipsilateral superior articular process. In 1959, Boucherlo' described his method that uses the same starting point as King, but the screw is directed more vertical into the pedicle thereby increasing the length of the screw in the caudal vertebrae.

Magerl's screw is significantly longer because the entry point is at the base of the contralateral spinous process. This increases the effective working length of the screw on both sides of the facet joint thus increasing strength of the fixation. The anatomic angle of screw insertion and screw length 102 at the various levels in the lumbar spine has been studied for this technique and transiaminar facet screw stabilization has been successfully used after selective decompression for spinal stenosis and disc protrusion (103). Biomechanical studies have demonstrated significant stability in flexion, extension, and rotation (104).

Translaminar facet screws significantly increase the stiffness of spinal motion segments (105). When coupled with threaded cylindrical interbody fusion devices, translaminar facet screws provide substantial stability in the weakest loading directions, extension and axial rotation (83,84). lnterbody cages separate the facet surfaces with distraction, which reduces the role of the facets in extension and axial rotation (81). Translaminar facet screws stabilize this facet uncoupling caused by the interbody distraction. Translaminar facet screw technique has also been evaluated in a biomechanical model of PLIF. Zhao(106) compared the segmental stiffness of three different PLIF constructs: two posterior cages, a single long diagonally placed threaded cylindrical cage from a posterolateral position, and the single long posterolateral cage with simultaneous facet joint fixation. The two, standard PLIF cages construct was the weakest due to the need for bilateral facetectomy and posterior element destruction, which is detrimental to segmental stiffness. The single posterolateral cage technique requires only a unilateral facetectomy and conserves more of the posterior elements. As expected, this model was more stable than the two–cage construct. The addition of translaminar joint fixation to the remaining facet provided significantly more stability in compression, extension, flexion, bending, and torsion. This study clearly proves the advantage of even unilateral facet stabilization, and the disadvantage of the standard PLIF approach, which results in a profound decrease in biomechanical stiffness. Extensive removal of the posterior elements is required to insert the cylindrical cages of appropriate size and kyphosis may occur when larger cages are used. Also, cauda equina retraction is necessary during insertion of these cages and may be severe with potential neurologic damage when appropriate, larger cages are employed.

In conclusion, technical and biomechanical advantages support the combination of interbody cages and least invasive posterior translaminar facet screw fixation. An ALIF approach is less damaging to the soft tissues and supporting structures of the spine than a PLIF technique for interbody fusion. Clinically, Vamvanij (107) found simultaneous ALIF with BAK cages and posterior facet fusion offered the highest fusion rate, pain relief, and clinical success compared to three other lumbar fusion techniques. Limited, posterior soft tissue dissection only to the facet joints appears to be important. lnterbody fusion cages are least able to resist extension due to distraction and restoration of disc height, which uncouples the posterior facet joints. Insertion of transfacet screws significantly increases the stiffness in an interbody cage model, especially in extension.(83, 84) Extension moments on a stand–alone interbody cage without posterior stabilization tends to separate the vertebral endplates from the interbody cage, potentially resulting in nonunion, loosening, or migration of the cage. Stiffness of a cage model loaded in compression is also significantly greater with the addition of facet screws (84). Thus, transiaminar facet screws should help resist collapse and subsidence of the cage as well as loss of lordosis and foraminal narrowing. In the future, this concept may be developed even further with the minimally invasive percutaneous delivery of transiaminar facet screws under real–time image guided control.

Now here's the REAL kicker. Steven, Elaine: this study addresses the fact that taking pedicle screws out is so fraught with danger that even when indicated, it should be considered with caution. The authors used a minimalistic way to remove the screws. I've not been offered this.

: Spine J. 2004 Nov-Dec;4(6):701-5.Links

Minimally invasive removal or revision of lumbar spinal fixation.
Salerni AA.

Orthopedic Professional Association, Gilford, NH 03249, USA. asalerni@orthopa.com

BACKGROUND CONTEXT: There are both absolute and relative indications for the removal of pedicle screw fixation in the lumbar spine. Whatever the reasons are, removal of this hardware has required a surgical dissection that has been generally as extensive as the one used for their initial placement. These dissections are always disabling in the short term. In fact, the magnitude of this disabling pain can be significant enough so as to effectively eliminate screw removal as a logical treatment option for many conditions where indications for removal are only relative.Percutaneous pedicle screw fixation has served to amplify the stakes associated with this dilemma.In fact, this new technique makes the need for a less invasive method of pedicle screw removal greater now than ever.

PURPOSE: This paper describes a minimal access surgical technique for pedicle screw construct removal that employs the tubular retractor system that was originally developed for microendoscopic discectomy.

STUDY DESIGN: This case study represents a summary of the surgical experience gained from the first 10 patients to have undergone removal or revision of pedicle screw constructs by this minimally invasive method. METHODS: A retrospective analysis of pre- and postoperative clinical data was gathered from the hospital records. Surgical times and blood loss were also extracted from these records. The procedure is described in detail. Interpretation of the surgical parameters and clinical effects are discussed. RESULTS: Six patients presented with a radiculopathy secondary to a misdirected pedicle screw.Two of these patients were admitted for simple removal. The four remaining patients who had undergone percutaneous pedicle screw fixation developed acute radicular pain from a misdirected screw.These patients underwent revision of their constructs by this method. Screws were also removed unilaterally in four other patients as the initial phase to revision or additional surgery. All procedures were performed through 16 mm tubular retractors. Operative time averaged 33 minutes for the group,and it ranged between 22 and 40 minutes. Hospital length of stay averaged I day for the group. Hospital stay averaged only 0.8 hospital days for the patients in whom screw removal was the primary goal. At 1 month after surgery no patient felt limited by incisional pain. No complications occurred.

CONCLUSIONS: Unlike most other minimal access surgical procedures, the learning curve for this procedure appears to be relatively flat. Removal of pedicle screw fixation in the manner described proved to be simple and straightforward. The benefits are dramatic and immediate. It is possible to complete the procedure within minutes, and the pain produced is best described as inconsequential.This minimally invasive technique radically alters both the intraoperative and postoperative courses for those who face pedicle screw removal. The disadvantages associated with the standard open approach are reduced to the production of mild short-term discomfort and an exposure to the potential risks of brief anesthesia and the possibility of a surgical infection. Considering that hospital stay should be limited to I day or less and that surgical times are less than I hour, minimally invasive removal or revision of hardware should reduce overall costs significantly.

LizaJane,

One of the people I'd definitely seek some insight/info. from is GJZH. She recently posted here:

http://neurotalk.psychcentral.com/thread44203.html

LizaJane,

You have to remember that you are having your hardware removed because of non-fusion...I do not know if that makes a difference in how it is removed and then replaced in your case. However, I would certainly call Dr. Bitan and ask him. He is open to discussion and does do minimally invasive procedures. When we discussed my surgery he apologized to me for not being able to offer me something minimally invasive....

He did just remove a long screw from my iliac and that surgery took 30 minutes. ...It was a very long screw with a rod attached at the very end of the fusion and the long screw then went into the ilium....It was removed because it no longer served a purpose and after injections into the SI joints we felt it was causing pain...

Dr. Bitan is not like other surgeons Liza...He will talk to you and call you at home..so if you have a question...send him this article and ask him to discuss it with you...


I only know about rods and screws and have only talked to people that have the rods and screws..Most people have good results though there are those that have had failed surgeries...It is why you have to do your homework and find good surgeons...I talked to many surgeons before I signed on the dotted line. I was always very happy with my decisions. I saw surgeons into the double digits before I decided on Dr. Bitan, so rest assured this was not a hasty decision for me, but it has to be one you are happy with as well. Dr. Bitan is French so he does things a little differently than other docs too...Do not forget, I am fused Liza from L1 to S1 and I am happy with my decision. I do still have pain, but every surgeon I saw told me I always will so I did not expect to be pain free and this was a second surgery for me...I had a laminectomy before this surgery....but I am happy with my decision...
Gloria