Adult low-grade acquired spondylolytic spondylolisthesis: evaluation and management

Stand-Alone Percutaneous Pedicle Screw Lumbar Fixation to Indirectly Decompress the Neural Elements in Spinal Stenosis: A Radiographic Assessment Case Series

BACKGROUND

 The ideal surgical treatment of lumbar canal stenosis remains controversial. Although decompressive open surgery has been widely used with good clinical outcome, minimally invasive indirect decompression techniques have been developed to avoid the complications associated with open approaches. The purpose of this study was to evaluate the radiologic outcome and safety of the indirect decompression achieved with stand-alone percutaneous pedicle screw fixation in the surgical treatment of lumbar degenerative pathologies.

METHODS

 Twenty-eight patients presenting with spinal degenerative diseases including concomitant central and/or lateral stenosis were treated with stand-alone percutaneous pedicle screw fixation. Radiographic measurements were made on axial and sagittal magnetic resonance (MR) images, performed before surgery and after a mean follow-up period of 25.2 months. Measurements included spinal canal and foraminal areas, and anteroposterior canal diameter.

RESULTS

 Percutaneous screw fixation was performed in 35 spinal levels. Measurements on the follow-up MR images showed statistically significant increase in the cross-sectional area of the spinal canal and the neural foramen, from a mean of 88.22 and 61.05 mm2 preoperatively to 141.52 and 92.18 mm2 at final follow-up, respectively. The sagittal central canal diameter increased from a mean of 4.9 to 9.1 mm at final follow-up. Visual analog scale (VAS) pain score and Oswestry Disability Index (ODI) both improved significantly after surgery (p < 0.0001).

CONCLUSION

 Stand-alone percutaneous pedicle screw fixation is a safe and effective technique for indirect decompression of the spinal canal and neural foramina in lumbar degenerative diseases. This minimally invasive technique may provide the necessary decompression in cases of common degenerative lumbar disorders with ligamentous stenosis.

Trans-isthmic pars interarticularis screw fixation under CT and fluoroscopic guidance: technical success and clinical outcome in patients with symptomatic low-grade lumbar isthmic lysis

OBJECTIVES

To assess the technical success of trans-isthmic screw fixation with simultaneous CT and fluoroscopic guidance in patients with symptomatic low-grade isthmic spondylolisthesis.

METHODS

Fifty patients (28 women and 22 men; mean age ± standard deviation: 50 years ± 18.9) presenting with symptomatic low back pain with isthmic spondylolisthesis refractory to medical management were treated by means of trans-isthmic pars interarticularis percutaneous screw fixation. The procedure was performed under local anesthesia with double CT and fluoroscopic guidance. Primary outcome was technical success of the procedure, which was assessed with a post-procedure CT using the same success criteria as surgical screw placement with regard to entry point, trajectory, and screw tip. Secondary outcome was pain decrease assessed by the Visual Analog Scale (VAS).

RESULTS

Ninety-nine procedures were performed in 50 patients and 99 screws were inserted. Postoperative CT assessment showed satisfactory screw placement in 96 cases, reflecting a technical success rate of 96.9%. No complications occurred during or after the procedure. Pain assessment showed a pain decrease of VAS score from a median of 7 (min 5, max 10; MAD 1.4) to 2 (p < 0.0001) (min 0, max 7, MAD 1.7) with a mean follow-up of 39 months.

CONCLUSION

Trans-isthmic screw fixation performed under CT and fluoroscopic guidance presents a high technical success and appears as a safe procedure and effective procedure in patients with symptomatic low-grade isthmic lysis.

KEY POINTS

• Trans-isthmic pars interarticularis percutaneous screw insertion is feasible under double CT and fluoroscopic guidance by a radiologist with a high technical success. • This technique can be performed under local anesthesia only. • In patients with chronic low back pain, isthmic screwing allows long-term pain improvement.

Comparison of Clinical Outcomes Between Posterior Instrumented Fusion With and Without Interbody Fusion for Isthmic Spondylolisthesis

STUDY DESIGN

A multicenter ambispective study using the Canadian Spine Outcomes and Research Network to compare clinical outcomes in adult patients with isthmic spondylolisthesis who received surgery.

OBJECTIVE

The purpose of this study is to compare 1-year postoperative clinical outcomes between posterior instrumented fusion with and without interbody fusion in patients with isthmic spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Despite the increased use of interbody fusion in patients with isthmic spondylolisthesis, clinical superiority has not been demonstrated. It remains unclear what the optimal surgical approach is for this population.

MATERIALS AND METHODS

The primary outcome was changed in leg pain at 1 year. Secondary outcomes were changed in Oswestry Disability Index, Short Form-12 Physical Component Score, and back pain at 1-year postoperative follow-up, estimated intraoperative blood loss, length of surgery, length of stay, number of transfusions, and adverse events. Descriptive statistics, Student t test, χ2 test, and stepwise multivariable regression were used for analysis.

RESULTS

In total, 300 patients were included in this study. Of the 300 patients, 252 received posterolateral instrumented fusion with interbody fusion and 48 received posterolateral instrumented fusion alone. There were no significant differences in primary and secondary clinical outcomes at 1-year postoperative follow-up between the 2 groups. There were no significant differences in estimated blood loss (441 vs. 356 mL), length of surgery (210 vs. 224 min), length of stay (4 vs. 4 d), rate of transfusions (5.6% vs. 8.3%), and number of adverse events (33% vs. 23%) between patients who received interbody fusion and patients who did not. The addition of interbody fusion was not a significant variable for primary and secondary clinical outcomes in the stepwise multivariable regression analysis.

CONCLUSIONS

There were no significant differences in clinical outcomes at 1 year or in the number of early complications between patients who received posterolateral fusion or posterior/transformational lumbar interbody fusion.

LEVEL OF EVIDENCE

Level III.

Long-term outcome of fusion for degenerative disc disease in the lumbar spine

Aims

Chronic low back pain due to degenerative disc disease is sometimes treated with fusion. We compared the outcome of three different fusion techniques in the Swedish Spine Register: noninstrumented posterolateral fusion (PLF), instrumented posterolateral fusion (IPLF), and interbody fusion (IBF).

Patients and Methods

A total of 2874 patients who were operated on at one or two lumbar levels were followed for a mean of 9.2 years (3.6 to 19.1) for any additional lumbar spine surgery. Patient-reported outcome data were available preoperatively (n = 2874) and at one year (n = 2274), two years (n = 1958), and a mean of 6.9 years (n = 1518) postoperatively and consisted of global assessment and visual analogue scales of leg and back pain, Oswestry Disability Index, EuroQol five-dimensional index, 36-Item Short-Form Health Survey, and satisfaction with treatment. Statistical analyses were performed with competing-risks proportional hazards regression or analysis of covariance, adjusted for baseline variables.

Results

The number of patients with additional surgery were 32/183 (17%) in the PLF group, 229/1256 (18%) in the IPLF group, and 439/1435 (31%) in the IBF group. With the PLF group as a reference, the hazard ratio for additional lumbar surgery was 1.16 (95% confidence interval (CI) 0.78 to 1.72) for the IPLF group and 2.13 (95% CI 1.45 to 3.12) for the IBF group. All patient-reported outcomes improved after surgery (p < 0.001) but were without statistically significant differences between the groups at the one-, two- and 6.9-year follow-ups (all p ≥ 0.12).

Conclusion

The addition of interbody fusion to posterolateral fusion was associated with a higher risk for additional surgery and showed no advantages in patient-reported outcome Cite this article: Bone Joint J 2019;101-B:1526–1533

Reverse Bohlman technique for treatment of high-grade spondylolisthesis in an adult population

BACKGROUND/AIMS

Surgical techniques for treatment of high-grade spondylolisthesis (HGS) remain controversial. This study aims to evaluate both radiographic and clinical outcomes in patients with HGS treated with the "modified Bohlman" and Reverse Bohlman technique.

METHODS

Review of consecutive HGS patients undergoing modified Bohlman and Reverse Bohlman at a single center from 2006 to 2018. Clinical, surgical, and radiographic data were collected.

RESULTS

Six patients identified in the modified Bohlman treatment arm: and eight patients in the Reverse Bohlman group. Twelve (12) patients presented with high grade congenital spondylolisthesis at L5-S1; one patient presented with dissolution of the L5 vertebral body secondary to uncontrolled osteomyelitis that developed after a previous failed fusion; and one patient presented with iatrogenic L5-S1 spondylolisthesis after a previous L3-S1 fusion. One patient had medially placement pedicle screw and associated radiculopathy. All follow-up post = operative scans demonstrated solid fusion. Postoperatively, anterolisthesis improved from 18.3% to 10.1% (p = .0586) and the slip angle improved from 60.43° of kyphosis to 48.71° (p = .0139). No spondylolisthesis translational reduction maneuvers were attempted intraoperatively except for positioning on a sacral cushion to increase lordotic angle. Lumbar lordosis improved from 65.29 to 63.86 postoperatively. Four of our fourteen patients had long-term median follow-up of 28 months (range = 19-48 months) slip angle, percentage, and lumbar lordosis all improved from the patient's pre-operative measurements. The improvement in slip angle was nearly statistically significant with a p-value of 0.065.

CONCLUSIONS

Reverse Bohlman technique for high grade spondylolisthesis is a viable option when seeking to address adjacent level instability or slip.

Long-term outcome after spinal fusion for isthmic spondylolisthesis in adults

BACKGROUND CONTEXT

Data on the long-term outcome after fusion for isthmic spondylolisthesis are scarce.

PURPOSE

To study patient-reported outcomes and adjacent segment degeneration (ASD) after fusion for isthmic spondylolisthesis and to compare patient-reported outcomes with a control group.

STUDY DESIGN/SETTING

A prospective study including a cross-sectional control group.

PATIENT SAMPLE

Patients with isthmic spondylolisthesis underwent posterior lumbar interbody fusion (PLIF) (n=86) or posterolateral fusion (PLF) (n=77). Patient-reported outcome data were available for 73 patients in the PLIF group and 71 in the PLF group at a mean of 11 (range 5-16) years after baseline. Seventy-seven patients in the PLIF group and 54 in the PLF group had radiographs at a mean of 14 (range 9-19) years after baseline. One hundred thirty-six randomly selected persons from the population served as controls for the patient-reported outcomes.

OUTCOME MEASURES

Patient-reported outcomes include the following: global outcome, Oswestry Disability Index, Disability Rating Index, and Short Form 36. The ASD was determined from radiographs using the University of California Los Angeles (UCLA) grading scale.

METHODS

The chi-square test or analysis of covariance (ANCOVA) was used for group comparisons. The ANCOVA was adjusted for follow-up time, smoking, Meyerding slippage grade, teetotaler (yes/no) and, if available, the baseline level of the dependent variable.

RESULTS

There were no significant patient-reported outcome differences between the PLIF group and the PLF group. The prevalence of ASD was 42% (32/77) in the PLIF group and 26% (14/54) in the PLF group (p=.98). The patient-reported outcome data indicated lower physical function and more pain in individuals with surgically treated isthmic spondylolisthesis compared to the controls.

CONCLUSIONS

PLIF and PLF groups had similar long-term patient-reported and radiological outcomes. Individuals with isthmic spondylolisthesis have lower physical function and more pain several years after surgery when compared to the general population.

Two-level reverse Bohlman transsoseous approach for treatment of symptomatic pseudarthrosis

Surgical treatment for high-grade spondylolisthesis with high sacral slope remains controversial and no definitive gold standard procedure has been identified. The Bohlman technique, in which a fibular strut is reamed posteriorly across the L5-S1 disc space in an oblique, inferior to superior trajectory, has been increasingly utilized. Recently, a Reverse Bohlman technique has been described, in which a graft is reamed anteriorly across a single disc space in a superior to inferior trajectory. Case Report A 55 year-old male with complete lumbarization of S1 (referred to as L6) and previous L5-L6-S1 posterior instrumented fusion presented, with progressively worsening low back pain and lower extremity radicular pain. After failing conservative management, he underwent a 2-level Reverse Bohlman approach to place a titanium mesh interbody graft (cage) anteriorly from L5 to S1, crossing the L5-6 and L6-S1 disc spaces. Here we describe for the first time a Reverse Bohlman technique spanning two disc spaces in a patient with a transitional lumbosacral anomaly and high sacral slope. At 6 months post-operative follow up, the patient reported near complete resolution of symptoms.

Circumferential minimally invasive approach for low-grade isthmic spondylolisthesis: A clinical and radiological study of 43 patients

INTRODUCTION

Circumferential fusion for lumbar low-grade isthmic spondylolisthesis (LGIS) provides the best spinal stability and highest fusion rates. The aim of this study is to investigate results of minimal invasive management of LGIS and correlations between Intervertebral Foramen Surface (IFS) and other parameters.

METHODS

We retrospectively reviewed cases of 43 patients who underwent a minimally invasive circumferential fusion (Anterior lumbar interbody fusion followed by percutaneous posterior pedicle screw fixation) for LGIS between January 2010 and December 2014 in our institution. Inclusion criteria were one-level (L4-L5 or L5-S1) LGIS with low back and/or radicular pain. Pre- and postoperative radiographic evaluations were performed at 6, 12 and 24months. Measurements (Percentage of anterior displacement, degree of slip angle, height of the intervertebral space and the IFS) were obtained using Surgimap^®.

RESULTS

Nineteen patients (44.2%) were males. Mean age was 43 years old (19-72years). The mean follow-up of the series was 18.3months (3-72months). Mean preoperative Visual Analogy Scale (VAS) for low back pain decreased from 70mm to 20mm and from 80mm to 10mm as to radicular pain. Anterior displacement was reduced from 18% to 7% (p<0.01), degree of slippage were increased from 9.8° to 15.2° (p<0.01), intervertebral height was restored from 4.4mm to 8.5mm (p<0.01) and increase of the IFS was calculated 48.8%.

CONCLUSION

One stage circumferential fixation for adults' LGIS without decompression, allows restoration of intervertebral height permitting good reduction of the slippage, an increasing of the IFS and liberation of nerve roots.

Different Fusion Approaches for Single-level Lumbar Spondylolysis Have Similar Perioperative Outcomes

STUDY DESIGN

Retrospective cohort study OBJECTIVE.: The aim of this study was to compare perioperative adverse events for patients with lumbar spondylolysis treated with transforaminal lumbar interbody fusion (TLIF), posterior spinal fusion (PSF), combined anterior and posterior fusion (AP fusion), or anterior lumbar interbody fusion (ALIF).

SUMMARY OF BACKGROUND DATA

Previous cohort studies have shown similar long-term outcomes for different surgical approaches for this indication, but potential differences in 30-day perioperative adverse events have not been well characterized.

METHODS

The present study uses data extracted from the American College of Surgeons National Surgical Quality Improvement Database. Patients undergoing fusion with different approaches for lumbar spondylolysis were identified. Propensity score matching was utilized to account for potential differences in demographic and comorbidity factors. Comparisons among perioperative outcomes were then made among the propensity score-matched study groups.

RESULTS

Of 1077 cases of spondylolysis identified, 556 underwent TLIF, 327 underwent PSF, 108 underwent AP fusion, and 86 underwent ALIF. After propensity score matching, there were no differences in the rates of any of the 30-day individual adverse events studied and no differences in the aggregated groupings of any adverse event, serious adverse event, or minor adverse event. There was a significantly increased operative time in the AP fusion group, but there were no differences in hospital length of stay or readmission rates.

CONCLUSION

Because perioperative adverse event rates were similar, even with a slightly longer operative time in the AP fusion group, these findings suggest that surgeon preference and long-term outcomes are better used to determine the recommendation of one surgical approach over another for single level fusions for lumbar spondylolysis.

LEVEL OF EVIDENCE

3.

Multilevel Spondylolysis Repair Using the "Smiley Face" Technique with 3-Dimensional Intraoperative Spinal Navigation

BACKGROUND/OBJECTIVE

Multilevel spondylolysis is a rare cause of progressive lower back pain, and patients who fail conservative management are treated surgically. Direct repair methods can maintain mobility and lead to decreased morbidity compared with spinal fusion in single-level spondylolysis. In this paper, we present a patient with nonadjacent multilevel spondylolysis who underwent the "smiley face" technique of direct multilevel repair without fusion using 3-dimensional intraoperative spinal navigation.

METHODS

Bilateral spondylolysis at L3 and L5 with associated spondylolisthesis in a 50-year-old male was repaired using the "smiley face" technique. Patient-reported outcomes, including the Oswestry Disability Index (ODI) and visual analog scale scores for back and leg pain, were assessed preoperatively along with 6 weeks and 4 months postoperatively.

RESULTS

Postoperative computed tomography imaging showed precise screw insertion and rod placement along with stable hardware alignment in follow-up imaging. The patient's ODI and lower back visual analog scale scores decreased from 25 to 8 and 7.5 to 4, respectively, correlating to an excellent outcome on ODI.

CONCLUSION

Direct repair and avoidance of fusion is possible and can provide good functional outcomes in patients with nonadjacent multilevel spondylolysis and associated spondylolisthesis.

Microsurgical Posterolateral Foraminotomy on Patients with Adult Isthmic Spondylolisthesis

BACKGROUND

The standard surgical treatment for adult isthmic spondylolisthesis consists of various techniques of arthrodesis supplemented with instrumentation. However, the superiority of this strategy has not been irrefutably proved. Considering the risk associated with the instrumentation surgery, examining a less invasive approach is justified.

METHODS

We describe a series of 9 patients with adult isthmic spondylolisthesis, in whom we microsurgically decompressed the responsible nerve root in the intervertebral foramen through the posterolateral intermuscular approach. Technical details specific to isthmic spondylolisthesis were reviewed. The 2-year outcome was assessed with Short Form 36 and visual analog scale scores.

RESULTS

The mean age of the patients was 68 ± 7 years (standard deviation [SD]). The mean slip rate of spondylolisthesis measured on the preoperative lumbar radiography was 20% ± 12% (SD). All patients successfully underwent the procedure without complications. All the examined scores remained significantly better than the preoperative values 2 years after surgery; the mean visual analog scale score decreased from 7.8 ± 2.8 (SD) preoperatively to 2.8 ± 1.4 (SD) at 2 years (P = 0.008), average physical score of Short Form 36 improved from 33.1 ± 9.7 to 52.5 ± 9.4 (P = 0.001), and the bodily pain score improved from 28.0 ± 13.5 to 55.1 ± 9.7 (P = 0.001).

CONCLUSIONS

Microsurgical decompression through the posterolateral intermuscular approach was effective in producing good 2-year outcome in patients with adult isthmic spondylolisthesis. This procedure may be considered as a less invasive alternative in the surgical treatment of adult isthmic spondylolisthesis.

National Trends in the Surgical Management of Adult Lumbar Isthmic Spondylolisthesis: 1998 to 2011

STUDY DESIGN

A retrospective review.

OBJECTIVE

Isthmic spondylolisthesis (ISY) is a common orthopedic condition. Our objective was to identify trends in the surgical management of adult ISY in the United States and to evaluate trends in the surgical techniques utilized.

SUMMARY OF BACKGROUND DATA

Various surgical approaches have been described for ISY but preferred trends are not known.

METHODS

Using the Nationwide Inpatient Sample (NIS), 47,132 adult patients (≥ 18 years) with ISY undergoing lumbar spine fusion from 1998 to 2011 were identified. Our primary outcome of interest was the national trend in use of anterior (ASF), posterior (PSF), posterior with interbody (P/TLIF), and combined anterior-posterior fusion (A/PSF) surgeries for ISY patients. Poisson regression, modified Wald's test, and linear and logistic regression analysis with P < 0.05 were used for statistical analysis.

RESULTS

The annual rate of fusion surgeries for ISY increased 4.33 times-from 28.31 surgeries in 1998 to 122.69 surgeries per million US adults per year in 2011. Over the study period, annual rates of ASFs increased 2.65 times (P < 0.001), PSFs increased 1.03 times (P = 0.24), P/TLIFs increased 4.33 times (P < 0.001), and A/PSF increased 2.93 times (P < 0.001). In 2010 to 2011, the complication rate was significantly higher for A/PSF (18.86%, P < 0.001). PSFs had a higher complication rate of 3.61% and P/TLIFs (2.58%). The risk of complications was lower for females, elective admissions, and in hospitals in the South. Mean hospitalization charges adjusted to 2011 dollars were significantly higher for A/PSF ($157,560; 95% CI [95% confidence interval]: 14,480-170,360; P <  .001), followed by P/TLIFs ($103,700; 95% CI: 9840-109,030) and PSFs had lower mean hospitalization charges ($87,420; 95% CI: 8210-92,770).

CONCLUSION

Use of fusion for ISY has significantly increased and interbody fusion has become the most preferred approach over the study period. Hospital charges and complications were highest for combined anterior-posterior fusions.

"Reverse Bohlman" technique for the treatment of high grade spondylolisthesis in an adult population

BACKGROUND/AIMS

Surgical techniques for effective high-grade spondylolisthesis (HGS) remain controversial. This study aims to evaluate radiographic/clinical outcomes in HGS patients treated using modified "Reverse Bohlman" (RB) technique.

METHODS

Review of consecutive HGS patients undergoing RB at a single university-center from 2006 to 2013. Clinical, surgical, radiographic parameters collected.

RESULTS

Six patients identified: five with L5-S1 HGS with L4-L5 instability and one had an L4-5 isthmic spondylolisthesis and grade 1 L5-S1 isthmic spondylolisthesis. Two interbody graft failures and one L5-S1 pseudoarthrosis. Postoperative improvement of anterolisthesis (62.3% vs. 49.6%, p = 0.003), slip angle (10 vs. 5°, p = 0.005), and lumbar lordosis (49 vs. 57.5°, p = 0.049).

CONCLUSIONS

RB technique for HGS recommended when addressing adjacent level instability/slip.

Functional radiography in examination of spondylolisthesis

OBJECTIVE

Despite the predominant use of standing flexion-extension radiography for quantifying instability in isthmic and degenerative spondylolisthesis, other functional radio-graphic techniques have been presented in the literature.

CONCLUSION

The current evidence reported in the literature is insufficient to influence how the results of these other functional radiographic techniques should affect clinical management; however, it does raise doubts regarding the accuracy and reliability of standing flexion-extension radiography in this setting. Based on the currently available evidence and until randomized studies are performed to assess the efficacy of functional radiographic techniques in directing clinical decision making, positioning schemes other than traditional standing flexion-extension may be considered as options in the evaluation of patients with symptomatic isthmic and degenerative spondylolisthesis in which standard flexion-extension radiographs fail to show pathologic instability.

Bilateral tubular minimally invasive surgery for low-dysplastic lumbosacral lytic spondylolisthesis (LDLLS): analysis of a series focusing on postoperative sagittal balance and review of the literature

PURPOSE

To report our early experience with minimally invasive surgery (MIS) in low-dysplastic lumbosacral lytic spondylolisthesis (LDLLS), and to analyze the impact of surgery on postoperative spino-pelvic and sacro-pelvic parameters.

METHODS

Eight patients (mean age 47.6 years) underwent MIS for LDLLS involving in all but one the L5-S1 level. VAS and ODI were used for clinical assessment. Imaging included pre-operative X-rays, CT and MRI scans. Post-operatively, all patients underwent X-rays and CT-scans. Pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) values as well as lumbar lordosis (LL) have been derived from pre- and post-operative standard X-rays.

RESULTS

Mean follow-up is 30.12 months (range 15-42). No complications related to the surgical procedure were observed. Patients reported a satisfactory clinical outcome, as demonstrated by variation in mean VAS (from 9.1 to 3.6) and ODI (from 70.50 to 28.25 %) scores. Comparison between pre- and post-operative sacro-pelvic parameters documented moderate changes, with reduction of PT and increase of SS in all but one patient. Overall sagittal balance of the spine has been evaluated using the sagittal vertical axis (SVA), obtained from post-operative X-rays. Mean value of SVA demonstrated a good sagittal balance of the spine.

CONCLUSION

This series demonstrates that MIS is feasible and effective for LDLLS, as witnesses by the satisfactory clinical results maintained at medium-term follow-up. We submit that TLIF is a valid option but an adequately sized and positioned interbody cage is a key factor to allow satisfactory restoration of segmental lordosis.

Early results of stand-alone anterior lumbar interbody fusion in iatrogenic spondylolisthesis patients

BACKGROUND

Iatrogenic spondylolisthesis is a challenging condition for spinal surgeons. Posterior surgery in these cases is complicated by poor anatomical landmarks, scar tissue adhesion of muscle and dural structures and difficult access to the intervertebral disc. Anterior interbody fusion provides an alternative treatment method, allowing indirect foraminal decompression, reliable disc clearance and implantation of large surface area implants.

MATERIALS AND METHODS

A retrospective chart review of patients with iatrogenic spondylolisthesis including pre- and post-operative Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) scores was performed. Imaging criteria were pelvic incidence, overall lumbar lordosis and segmental lordosis. In addition, the fusion rate was investigated after 6 months.

RESULTS

Six consecutive patients treated between 2008 and 2011 (4 female, 2 male, mean age 61 ± 7.1 years) were identified. The initially performed surgeries included decompression with or without discectomy; posterior instrumented and non-instrumented fusion. The olisthetic level was in all cases at the decompressed level. All patients were revised with stand-alone anterior interbody fusion devices at the olisthetic level filled with BMP 2. Average ODI dropped from 49 ± 11 % pre-operatively to 26.0 ± 4.0 at 24 months follow-up. VAS average dropped from 7 ± 1 to 2 ± 0. Mean total lordosis of 39.8 ± 2.8° increased to 48.5 ± 4.9° at pelvic incidences of 48.8 ± 6.8° pre-operatively. Mean segmental lordosis at L4/5 improved from 10.5 ± 6.7° to 19.0 ± 4.9° at 24 months. Mean segmental lordosis in L5/S1 increased from 15.1 ± 7.4° to 23.2 ± 5.6°. Cage subsidence due to severe osteoporosis occurred in one case after 5 months, and hence there was no further follow-up. Fusion was confirmed in all other patients.

CONCLUSION

Anterior interbody fusion offers good stabilisation and restoration of lordosis in iatrogenic spondylolisthesis and avoids the well-known problems associated with reentering the spinal canal for revision fusions. In this group, ODI and VAS scores were improved.

Reduction and transforaminal lumbar interbody fusion with posterior fixation versus transsacral cage fusion in situ with posterior fixation in the treatment of Grade 2 adult isthmic spondylolisthesis in the lumbosacral spine

OBJECT

In situ transsacral fusion in the treatment of low-grade isthmic spondylolisthesis has rarely been reported. The authors treated 13 cases of L-5 Grade 2 isthmic spondylolisthesis associated with collapsed disc space and osteoporosis by using transsacral fusion and fixation, and compared its clinical and radiological outcomes with the results of transforaminal lumbar interbody fusion (TLIF) and instrumental reduction in 21 patients.

METHODS

The authors retrospectively analyzed 21 patients in Group A who were treated with reduction and TLIF, and 13 patients in Group B who were treated with transsacral cage fusion. Oswestry Disability Index and visual analog scale scores of back and leg pain were used to evaluate clinical outcomes. Radiological parameters for assessment included the percentage of slippage, whole lumbar lordosis, and lumbosacral angle. Operative data, fusion rate, and perioperative complications were recorded as well.

RESULTS

The mean operation time and blood loss in Group B was less than that in Group A. Both groups realized good recovery from previous symptoms. The decrease in back and leg pain after surgery was significant within each group, without much difference between the 2 groups. No significant differences were found in lumbosacral angle, whole lumbar lordosis, visual analog scale score, and Oswestry Disability Index score between the 2 groups after surgery. The solid fusion rate was 95.2% in Group A and 92.3% in Group B. In Group A, 2 patients suffered from graft site pain, 1 had a superficial infection, and 1 had screw loosening; in Group B, dural tears were found in 2 patients, transient S-1 paresthesia in 2, and extensor hallucis longus muscle weakness in 1.

CONCLUSIONS

For patients with a collapsed disc space and poor bone quality, posterior in situ transsacral cage fusion may be used as an alternative to the TLIF procedure. The short-term clinical and radiological outcomes in the transsacral cage group were comparable with those in the TLIF group, although with a relatively higher neurological complication rate.

Contemporary management of isthmic spondylolisthesis: pediatric and adult

BACKGROUND

Isthmic spondylolisthesis is common in pediatric and adult patients. Most cases are asymptomatic. When symptomatic, nonsurgical treatment is an appropriate first step. Surgical treatment of this condition varies depending on patient age, degree of slip, presence of neurologic findings, and degree of deformity.

PURPOSE

To review the literature on the management of isthmic spondylolisthesis in pediatric and adult patients.

STUDY DESIGN

Review article.

METHODS

Literature review.

RESULTS AND CONCLUSIONS

Achieving a solid fusion leads to improved functional outcomes and reduction in pain. A circumferential fusion is associated with a higher fusion rate and has become more common, especially with high-grade slips. The need for reduction is controversial and is mostly indicated for patients with significant lumbosacral kyphosis and sagittal imbalance.

Instrumented posterior lumbar interbody fusion in adult spondylolisthesis

It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Acquired spondylolysis after implantation of a lumbar ProDisc II prosthesis: case report and review of the literature

STUDY DESIGN

A case of acquired lumbar spondylolysis following lumbar disc arthroplasty L5-S1 in an 40-year-old woman and review of the literature.

OBJECTIVES

To present and discuss a case of acquired lumbar spondylolysis after implantation of an artificial disc L5-S1 that may have impaired a good clinical result requiring additional posterior lumbar instrumentation and fusion in order to improve understanding of this condition and to propose an effective method of surgical management.

SUMMARY OF BACKGROUND DATA

Lumbar disc arthroplasty is a possible surgical option for patients with degenerative disc disease. Acquired spondylolysis is a rare but known complication of spinal fusion but has never been described as a consequence of mobile disc arthroplasty. The authors present the first case in the literature who developed this complication.

METHODS

A 40-year-old woman with severe osteochondrosis L5-S1 and discogenic lumbar back pain underwent implantation of an artificial disc. Surgery and postoperative course were uneventful and the patient improved significantly as for back pain and mobility. Eighteen months after surgery, the patient was again admitted to our outpatient clinic for back pain that had slowly increased over time.

RESULTS

The radiologic workup showed a new spondylolysis L5 without a spondylolisthesis. Because of unsuccessful conservative treatment, the patient underwent posterior lumbar instrumentation and fusion L5-S1, leading to a significant pain reduction and a good clinical outcome.

CONCLUSION

Spine surgeons should be aware of the possibility of lumbar disc arthroplasty to induce acquired spondylolysis impairing good clinical results.

Surgical treatment for unstable low-grade isthmic spondylolisthesis in adults: a prospective controlled study of posterior instrumented fusion compared with combined anterior-posterior fusion

BACKGROUND CONTEXT

The surgical treatment for low-grade isthmic spondylolisthesis in adults with intractable lumbar pain is usually spinal fusion. It has been postulated that anterior column reconstruction may be relatively advantageous in those patients with unstable slips.

PURPOSE

To compare the early and medium term treatment efficacy of two common fusion techniques in isthmic spondylolisthesis.

STUDY DESIGN/SETTING

Prospective controlled trial comparing single-level posterior-lateral instrumented fusion with combined anterior and posterior-lateral instrumented fusion in sequential matched cohorts of patients with radiographically unstable isthmic spondylolisthesis.

OUTCOME MEASURES

Primary outcome measure of success was an Oswestry Disability Index (ODI)<or=20. Secondary outcome measures included patient determined minimum-acceptable outcome on four questionnaires: pain intensity (visual analog scale), ODI, medication intake, and work status. Radiographic outcome of fusion was determined by radiographic union and motion on flexion/extension X-rays. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for primary outcome of success for combined fusion compared with posterior fusion.

METHODS

The study was conducted over a 6-year period. The first cohort of 50 consecutive patients was treated with a single-level instrumented posterior-lateral fusion; the second sequential cohort was treated with an anterior interbody fusion and the same posterior operation. Observations were made at baseline, 6 months, 1 year, and 2 years after surgery. Final radiographic assessment was made at 2 years after surgery.

RESULTS

Baseline demographic and clinical factors were well-matched in the two cohorts. At 2 years, 46 posterior-only fusion subjects and 47 combined fusion subjects completed the full follow-up regimen. Outcomes were better by all measures at 6 months and 12 months in the anterior-posterior cohort. Comparing the primary outcome measure (ODI outcome<or=20) in the posterior versus the combined groups, success was achieved at 6 months in 11 versus 30 (RR=2.67, 95% CI 1.53, 4.67; p=.0001); at 1 year, 20 versus 34 (RR=1.66, 95% CI 1.14, 2.42; p<.005); and at 2 years, 29 versus 36 subjects (RR=1.21, 95% CI 0.93, 1.59; p=.14). At 6 months, 13 posterior-only and 25 combined group subjects had returned to work (RR 1.88, 95% CI 1.10, 3.21; p=.01). More patients achieved their preoperatively determined minimum-acceptable outcome at each time point. There were three nonunions in the posterior-alone cohort and one in the combined group. Serious complications and reoperations were similar in both groups.

CONCLUSION

Outcomes up to 2 years were superior by clinically important differences after a combined anterior-posterior operation compared with posterior-alone surgery for unstable spondylolisthesis; however, between-group differences attenuated appreciably after 6 months. The apparent clinical and occupational benefits of combined fusion should be considered along with possible increases in minor complications and procedure-related costs.