Intact arch spondylolisthesis. A review of 50 cases and description of surgical treatment

Lumbar Spinal Stenosis Associated With Degenerative Lumbar Spondylolisthesis: A Systematic Review and Meta-analysis of Secondary Fusion Rates Following Open vs Minimally Invasive Decompression

Background

Decompression without fusion is a treatment option in patients with lumbar spinal stenosis (LSS) associated with stable low-grade degenerative spondylolisthesis (DS). A minimally invasive unilateral laminotomy (MIL) for "over the top" decompression might be a less destabilizing alternative to traditional open laminectomy (OL).

Objective

To review secondary fusion rates after open vs minimally invasive decompression surgery.

Methods

We performed a literature search in Pubmed/MEDLINE using the keywords "lumbar spondylolisthesis" and "decompression surgery." All studies that separately reported the outcome of patients with LSS+DS that were treated by OL or MIL (transmuscular or subperiosteal route) were included in our systematic review and meta-analysis. The primary end point was secondary fusion rate. Secondary end points were total reoperation rate, postoperative progression of listhetic slip, and patient satisfaction.

Results

We identified 37 studies (19 with OL, 18 with MIL), with a total of 1156 patients, that were published between 1983 and 2015. The studies' evidence was mostly level 3 or 4. Secondary fusion rates were 12.8% after OL and 3.3% after MIL; the total reoperation rates were 16.3% after OL and 5.8% after MIL. In the OL cohort, 72% of the studies reported a slip progression compared to 0% in the MIL cohort, respectively. After OL, satisfactory outcome was 62.7% compared to 76% after MIL.

Conclusion

In patients with LSS and DS, minimally invasive decompression is associated with lower reoperation and fusion rates, less slip progression, and greater patient satisfaction than open surgery.

Clinical outcomes of degenerative lumbar spinal stenosis treated with lumbar decompression and the Cosmic "semi-rigid" posterior system

Background

Although some investigators believe that the rate of postoperative instability is low after lumbar spinal stenosis surgery, the majority believe that postoperative instability usually develops. Decompression alone and decompression with fusion have been widely used for years in the surgical treatment of lumbar spinal stenosis. Nevertheless, in recent years several biomechanical studies have shown that posterior dynamic transpedicular stabilization provides stabilization that is like the rigid stabilization systems of the spine. Recently, posterior transpedicular dynamic stabilization has been more commonly used as an alternative treatment option (rather than rigid stabilization with fusion) for the treatment of degenerative spines with chronic instability and for the prevention of possible instability after decompression in lumbar spinal stenosis surgery.

Methods

A total of 30 patients with degenerative lumbar spinal stenosis (19 women and 11 men) were included in the study group. The mean age was 67.3 years (range, 40–85 years). Along with lumbar decompression, a posterior dynamic transpedicular stabilization (dynamic transpedicular screw–rigid rod system) without fusion was performed in all patients. Clinical and radiologic results for patients were evaluated during follow-up visits at 3, 12, and 24 months postoperatively.

Results

The mean follow-up period was 42.93 months (range, 24–66 months). A clinical evaluation of patients showed that, compared with preoperative assessments, statistically significant improvements were observed in the Oswestry and visual analog scale scores in the last follow-up control. Compared with preoperative values, there were no statistically significant differences in radiologic evaluations, such as segmental lordosis angle (α) scores (P = .125) and intervertebral distance scores (P = .249). There were statistically significant differences between follow-up lumbar lordosis scores (P = .048). There were minor complications, including a subcutaneous wound infection in 2 cases, a dural tear in 2 cases, cerebrospinal fluid fistulas in 1 case, a urinary tract infection in 1 case, and urinary retention in 1 case. We observed L5 screw loosening in 1 of the 3-level decompression cases. No screw breakage was observed and no revision surgery was performed in any of these cases.

Conclusions

Posterior dynamic stabilization without fusion applied to lumbar decompression leads to better clinical and radiologic results in degenerative lumbar spinal stenosis. To avoid postoperative instability, especially in elderly patients who undergo degenerative lumbar spinal stenosis surgery with chronic instability, the application of decompression with posterior dynamic transpedicular stabilization is likely an important alternative surgical option to fusion, because it does not have fusion-related side effects, is easier to perform than fusion, requires a shorter operation time, and has low morbidity and complication rates.

In situ local autograft for instrumented lower lumbar or lumbosacral posterolateral fusion

This study evaluated the effectiveness of local in situ autografts in instrumented posterolateral fusion of the lower lumbar or lumbosacral spine for treating degenerative spondylolisthesis. The subjects were 182 degenerative spondylolisthesis patients with spinal canal stenosis who, in one operation, underwent lumbar laminectomy with two-level (L3-4, L4-5 or L5-S1) transpedicle screw/rod system instrumentation and posterolateral fusion using autogenous spinous processes and laminae as the only source of bone grafts. The surgical results were assessed clinically and radiologically. All patients received follow-up for at least eighteen months. At the end of follow-up, bilateral fusion mass was radiographically confirmed in 113 (62%) patients, unilateral fusion mass was observed in fifty-seven (31%) patients, and twelve (7%) patients exhibited no fusion mass at the arthrodesis level. The clinical outcome was rated excellent/good in 138 (76%) patients, fair in thirty-five (19%) and poor in nine (5%). Use of in situ local autografts yields satisfactory clinical results in instrumented posterolateral spinal fusion. No significant correlation was noted between the level of arthrodesis and the radiological outcome, nor between the level of arthrodesis and the clinical outcome. Radiographic evaluation of bony fusion mass was not predictive of the clinical findings.

Surgical management of lumbar stenosis: decompression and indications for fusion

Review of the clinical, neuroradiological, and surgical management of lumbar spinal stenosis reveals that 90 to 95% of congenital or acquired variants may be adequately managed by means of decompression without fusion. These decompressive procedures often simultaneously treat disc herniations, limbus fractures, degenerative spondylolisthesis, rare selected cases of spondylolisthesis accompanied by lysis in older patients, and degenerative scoliosis. Fusion should be reserved for the approximately 5 to 10% of patients in whom there is clinical evidence of instability prior to surgery or for the few who develop slippage following laminectomy and facetectomy.

Referral guidelines: carpal tunnel syndrome

The contribution on the postoperative management and rehabilitation of patients with carpal tunnel syndrome should be carefully considered by every surgeon. The operation is simply not over when the last stitch goes in; careful postoperative management is quite important if one is to obtain optimal surgical results. The principles outlined here are valuable and help to explain the occasional poor outcome. We have become convinced that the use of a dorsal splint in the 1st week to 10 days following surgery is a helpful measure. It is designed to prevent the median nerve from prolapsing forward and becoming adherent to or trapped by the edges of the severed transverse carpal ligament. With regard to surgical management of carpal tunnel syndrome. It is exceedingly important to continue producing outcome studies showing that our interventions really do eliminate the problem and allow people to return to productive work. Templates for outcome assessment are under development by the Outcomes Committee of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons and also by the American College of surgeons. Hopefully, they can be applied to the treatment of carpal tunnel syndrome. The following segment represents some suggested referral guidelines for patients with carpal tunnel syndrome. The present differential diagnosis, methods of confirming the diagnosis, and appropriate indications for considering surgery. These guidelines have been reviewed by the various authors who have contributed to this issue of Neurosurgical Focus and other colleagues in neurosurgery, orthopedics, plastic surgery, neurology, and occupational therapy. It is hoped that they will be a reasonable start in our efforts to inform referring physicians as to the nature of median thenar neuropathy and its overall management.

The role of spinal fusion in surgery for lumbar spinal stenosis: a review

The authors undertook a review of the literature and analysis of the local surgical experience for lumbar stenosis to define the role of simultaneous arthrodesis in the treatment of patients undergoing decompression for spinal stenosis. The restrained use of spinal fusion is recommended in spinal stenosis surgery because of the coexisting medical problems in the elderly patient population and the higher associated complication rate with spinal fusion and instrumentation. A spinal fusion is recommended when decompression is performed in an area of segmental instability as manifested by gross movement on flexion--extension radiographs; when the decompression coincides with an area of degenerative instability, as with scoliosis or spondylolisthesis; or when the decompression creates an iatrogenic instability by the disruption of the posterior elements. The use of spine instrumentation as an adjunct to fusion is recommended when an area of degenerative instability shows evident gross instability or has had additional destabilizing procedures, such as a discectomy or a facetectomy. Spinal fusion is not recommended for a routine decompressive laminectomy for lumbar stenosis or in the case of stable degenerative deformities. New fusion techniques may improve the outcome and decrease the morbidity associated with contemporary methods of spinal fusion and instrumentation.

Indications for fusion following decompression for lumbar spinal stenosis

Degenerative lumbar spinal stenosis is a common condition affecting middle-aged and elderly people. Significant controversy exists concerning the appropriate indications for fusion following decompressive surgery. The purpose of this report is to compare the clinical outcomes of patients who were and were not treated with fusion following decompressive laminectomy for spinal stenosis and to identify whether fusion was beneficial. The authors conclude that patients in whom concomitant fusion procedures were performed fared better than patients who were treated by means of decompression alone when evidence of radiological instability existed preoperatively.

Clinical outcomes and radiological instability following decompressive lumbar laminectomy for degenerative spinal stenosis: a comparison of patients undergoing concomitant arthrodesis versus decompression alone

One hundred twenty-four patients with degenerative lumbar stenosis underwent decompression with fusion (32 patients) and without fusion (92 patients) during a 30-month period between 1986 and 1988. Patient-reported satisfaction at a mean follow-up period of 5.8 years (range 4.6-6.8 years) revealed a 79% good or fair outcome and a 21% poor outcome (26 patients). Seven patients (6%) developed lumbar instability, three patients (2%) developed new stenosis at an adjacent unoperated level, and three patients (2%) developed a new disc herniation between 2 and 5 years after surgery. Progressive postoperative spondylolisthesis occurred in 31% of patients with normal preoperative alignment (mean 7.8 mm, range 2-20 mm) and in 73% of patients with preoperative subluxation (mean 5.1 mm, range 2-13 mm) in whom fusion was not attained. Radiological progression did not correlate well with patient-reported outcome. The major conclusions from this study are the following: 1) the majority of patients respond well to this surgery, but complication (22%) and late deterioration (10%) rates are not insignificant; 2) radiological instability is common after decompression for degenerative lumbar spinal stenosis, but this correlates poorly with clinical outcome; 3) there are no definitive clinical or radiological factors that preoperatively predict patients at risk for a poor outcome; 4) post-operative radiological instability is more likely to occur when the following criteria are present: preoperative spondy-degenerated L-4 or a markedly degenerated L-3 disc; and when a radical and extensive decompression greater than one level is planned; and 5) the group at greatest risk for a poor outcome consists of those patients with normal preoperative alignment who do not suffer slippage following surgery.

Reduction and stabilization without laminectomy for unstable degenerative spondylolisthesis: a preliminary report

Fifty-two patients with unstable degenerative spondylolisthesis treated with the "AO internal fixator" and posterolateral fusion were reviewed. The major purpose of this study is to observe whether this pedicle fixation system could adequately decompress the nervous system tissue by the restoration of the spinal canal and, hence, replace the conventional decompressive laminectomy for the treatment of this disease entity. The results were satisfactory, showing that 92% of the patients with radicular pain, 89% of the patients with low back pain, and 86% of the patients with intermittent claudication improved postoperatively. Observing the results, only two groups of patients with unstable degenerative spondylolisthesis are not suitable for this treatment modality. The first group consists of those patients who have a spondylolisthesis with borderline instability. The second group consists of those patients who have a positive Lasèque's sign.

Outcome after laminectomy for lumbar spinal stenosis. Part I: Clinical correlations

All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metropolitan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient questionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore necessary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy.

Outcome after laminectomy for lumbar spinal stenosis. Part II: Radiographic changes and clinical correlations

The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels. This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.

Surgical management of neurogenic claudication in 100 patients with lumbar spinal stenosis due to degenerative spondylolisthesis

100 consecutive patients with neurogenic claudication due to segmental spinal stenosis in degenerative spondylolisthesis have been analyzed prospectively with respect to their clinical presentation, radiological and intra-operative findings, operative techniques and surgical results. By including 6 patients who had to be operated upon again overall results were excellent in 91, good in 4, satisfactory and moderate in 2, respectively, and poor in 1 patient (mean period of postoperative observation: 2.9 years). Three different techniques of spinal instrumentation are evaluated with respect to the surgical results. After microsurgical decompression of the neural elements 38 patients were fixed using the translaminar screw fixation method according to Magerl (re-operation necessary in 5), in 9 patients spondylodesis was achieved by the plate fixation method according to Louis (re-operation necessary in 1) and in 53 patients (as well as in the 6 patients who had to be re-operated on) primary Cotrel-Dubousset instrumentation was used. The best surgical results were obtained by laminectomy and Cotrel-Dubousset fixation. Instrumentation of more than 1 motion segment was restricted to patients with additional scoliosis or severe degenerative changes of the lumbar spine.