Documentation of outcomes for sacroiliac joint fusion: does prior spinal fusion influence the outcome?

Purpose

The purpose of this prospective case series (level II) was to determine the clinical outcomes of anterior SIJ fusion, comparing the outcomes of patients who had prior spinal fusions at any level compared to patients who have not.

Methods

This prospective study included 25 patients who underwent SIJ fusion with anterior plate fixation. All patients had failed non-operative treatment, had a positive Patrick test, and positive response to intra-articular SIJ injections with greater than 50 % pain relief. Patients had follow-up at 3, 6, 9 and 12 months where they completed Oswestry disability index (ODI) and Short Musculoskeletal Functional Assessment (SMFA) surveys. Outcome data are available for 19 patients who completed pre-operative and 12-month follow-up surveys. Their average time of the final follow-up was 1.1 years (range 10–33 months).

Results

Significant improvements between pre-operative and the final follow-up in ODI (p = 0.007) and SMFA (p = 0.01) were observed; the ODI assessed outcomes in patients who had previous spinal fusion surgery were significantly worse than those that did not at the final follow-up (p = 0.04).

Conclusion

Patients who have not undergone prior spinal fusion surgery, regardless of age, gender, and BMI have better outcomes following anterior SIJ fusion.     

Minimally invasive transforaminal lumber interbody fusion and degenerative lumbar spine disease

Objective

The purpose of this study was to assess the clinical and radiological outcomes of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) surgery for degenerative lumbar spine disease.

Methods

A prospective analysis of 34 consecutive patients who underwent a MI-TLIF using image guidance between July 2008 and November 2010. The patient group comprised 19 males and 15 females (mean age 56), 23 of whom had undergone additional reduction of spondylolisthesis. All patients underwent post-operative CT imaging to assess pedicle screw, cage placement and fusion at 6 months. Oswestry Disability Index (ODI) scores were recorded pre-operatively and at 6-month follow up.

Results

33/34 (97.1 %) patients showed evidence of fusion at 6 months with a mean improvement of 27 on ODI scores. The mean length of hospital stay was 4 days. The mean operative time was 173 min.

Complications observed

1/34 (2.9 %) suffered a pulmonary embolism and 1/34 (2.9 %) patients developed transient nerve root pain post-operatively. There were no occurrences of infection and no post-operative CSF leaks.

Conclusion

MI-TLIF offers patients a safe and effective surgical treatment option to treat degenerative lumbar spine disease.     

Improvement in low back pain following spinal decompression: observational study of 119 patients

Study design

Prospective clinical observational study of low back pain (LBP) in patients undergoing laminectomy or laminotomy surgery for lumbar spinal stenosis (LSS).

Objectives

To quantify any change in LBP following laminectomy or laminotomy spinal decompression surgery.

Patients and methods

119 patients with LSS completed Oswestry Disability Index questionnaire (ODI) and Visual Analogue Scale for back and leg pain, preoperatively, 6 weeks and 1 year postoperatively.

Results

There was significant (p < 0.0001) reduction in mean LBP from a baseline of 5.14/10 to 3.03/10 at 6 weeks. Similar results were seen at 1 year where mean LBP score was 3.07/10. There was a significant (p < 0.0001) reduction in the mean ODI at 6 weeks and 1 year postoperatively. Mean ODI fell from 44.82 to 25.13 at 6 weeks and 28.39 at 1 year.

Conclusion

The aim of surgery in patients with LSS is to improve the resulting symptoms that include radicular leg pain and claudication. This observational study reports statistically significant improvement of LBP after LSS surgery. This provides frequency distribution data, which can be used to inform prospective patients of the expected outcomes of such surgery.     

Comparison of minimally invasive fusion and instrumentation versus open surgery for severe stenotic spondylolisthesis with high-grade facet joint osteoarthritis

Purpose

The object of this study was to compare minimally invasive surgery (MIS) with open surgery in a severely affected subgroup of degenerative spondylolisthetic patients with severe stenosis (SDS) and high-grade facet osteoarthritis (FJO).

Methods

From January 2009 to February 2010, 49 patients with severe SDS and high-grade FJO were treated using either MIS or open TLIF. Intraoperative and diagnostic data, including perioperative complications and length of hospital stay (LOS), were collected, using retrospective chart review. Surgical short- and long-term outcomes were assessed according to the Oswestry disability index (ODI) and visual analog scale (VAS) for back and leg pain.

Results

Comparing MIS and open surgery, the MIS group had lesser blood loss, significantly lesser need for transfusion (p = 0.02), more rapid improvement of postoperative back pain in the first 6 weeks of follow-up and a shorter LOS. On the other hand, we experienced in the MIS group a longer operative time. The distribution on the postoperative ODI (p = 0.841), VAS leg (p = 0.943) and back pain (p = 0.735) scores after a mean follow-up of 2 years were similar. The overall proportion of complications showed no significant difference between the groups (29 % in the MIS group vs. 28 % in the open group, p = 0.999).

Conclusion

Minimally invasive surgery for severe SDS leads to adequate and safe decompression of lumbar stenosis and results in a faster recovery of symptoms and disability in the early postoperative period.     

Reliability and validity study on the Hungarian versions of the Oswestry Disability Index and the Quebec Back Pain Disability Scale

Purpose

Patient-reported outcome measurements (PROMs) are widely used in spine care. The development of reliable and valid National versions of spine-related disability questionnaires is strongly recommended from both the clinical and scientific points-of-view. The aims of this study were to adapt and validate the Oswestry Disability Index (ODI) and the Quebec Back Pain Disability Scale (QDS) for use with the Hungarian language.

Methods

After translating and culturally adapting the ODI and QDS, 133 patients with lumbar degenerative spinal disorder filled in the questionnaire booklet twice within 2 weeks. Subjects completed the Hungarian versions of the two PROMs as well as the WHOQoL-BREF validated as a general life quality questionnaire and Visual Analogue Scale of pain. Internal consistency, reliability and construct validity of the questionnaires were determined, as were the standard error of measurement (SEM) and minimal detectable change (MDC) scores.

Results

The Hungarian ODI consisted of one factor that showed good internal consistency (Cronbach-α 0.890). The QDS showed a four-factor structure with Cronbach-α values between 0.788 and 0.917. No significant floor or ceiling effects were observed. The test–retest analysis showed excellent reliability of the Hungarian ODI and QDS. The intraclass correlation coefficients (ICC) were 0.927 and 0.923, respectively. SEM values of 4.8 and 5.2 resulted in a MDC of 13 and 14 points in the Hungarian ODI and QDS, respectively. The correlation coefficient (r) between pain and ODI was 0.680 (p < 0.001) and the correlation between the ODI and the physical subscale of WHOQoL was also very good (r = ?0.705, p < 0.001). The QDS total score and its four subscales correlated significantly with pain and with the physical subscale of WHOQoL (r > 0.4, p < 0.001). The level of disability measured by the Hungarian ODI and QDS was significantly higher in the surgical subgroup than in non-surgically treated patients (p < 0.001).

Conclusions

Translation and cultural adaptation of the ODI and QDS were successful. Hungarian versions of the ODI and QDS proved to be reliable, valid PROMs confirming that they can be used in future clinical and scientific work with Hungarian-speaking spine patients.     

Management of catastrophising and kinesiophobia improves rehabilitation after fusion for lumbar spondylolisthesis and stenosis. A randomised controlled trial

Purpose

To evaluate the effect of a rehabilitation programme including the management of catastrophising and kinesiophobia on disability, dysfunctional thoughts, pain, and the quality of life in patients after lumbar fusion for degenerative spondylolisthesis and/or lumbar spinal stenosis.

Methods

This was a parallel-group, randomised, superiority-controlled study in which 130 patients were randomly assigned to a programme consisting of exercises and cognitive-behavioural therapy (experimental group, 65 subjects) or exercises alone (control group, 65 subjects). Before treatment (T1), 4 weeks later (post-treatment analysis, T2) and 12 months after the end of treatment (follow-up, T3), all the patients completed a booklet containing the Oswestry Disability Index (ODI, primary outcome), the Tampa Scale for Kinesiophobia, the Pain Catastrophising Scale, a pain Numerical Rating Scale, and the Short-Form Health Survey. A linear mixed model for repeated measures was used for each outcome measure.

Results

The ODI linear mixed model revealed significant main effects of group (F(1,122.8) = 95.78, p < 0.001) and time (F(2,120.1) = 432.02, p < 0.001) in favour of the experimental group. There was a significant group × time interaction effect (F(2,120.1) = 20.37, p < 0.001). The analyses of all of the secondary outcome measures revealed a significant effect of time, group and interaction in favour of the experimental group.

Conclusion

The rehabilitation programme, including the management of catastrophising and kinesiophobia, was superior to the exercise programme in reducing disability, dysfunctional thoughts, and pain, and enhancing the quality of life of patients after lumbar fusion for degenerative spondylolisthesis and/or LSS. The effects lasted for at least 1 year after the intervention ended.     

Clinical assessment of a CMC/PEO gel to inhibit postoperative epidural adhesion formation after lumbar discectomy: a randomized, control study

Purpose

To evaluate effectiveness of carboxymethylcellulose/polyethylene oxide (CMC/PEO) gel in improving clinical outcomes after the first-time lumbar discectomy.

Method

Ninety-three patients with herniated lumbar disc at L4–L5 or L5–S1 were enrolled and randomized into two groups: CMC/PEO gel treatment group and control group. All the patients underwent laminotomy and discectomy by posterior approach. The preoperative and postoperative Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) scores for lower-back pain and leg pain were analyzed and compared between two groups at 30- and 60-day time points.

Results

No patient presented with any clinically measurable adverse event during surgery. There were no significant differences between the treated group and the control group on the preoperative ODI and VAS scores. In general, the ODI and VAS scores decreased in both groups at all the time points. At the 30-day time point, the VAS scores for back pain and leg pain and the ODI scores in treatment group were lower by 9.9 % (P = 0.0302), 27.0 % (P = 0.0002) and 16.3 % (P = 0.0007) than those in control group. And at the 60-day time point, the ODI and VAS scores further decreased in both groups. The VAS scores for leg pain in treatment group were lower by 4.5 % than that in the control group (P = 0.0149). However, no significant difference was detected between two groups on the ODI and VAS scores for back pain.

Conclusions

The results demonstrated that CMC/PEO gel is effective in reducing posterior dural adhesions in the spine with no apparent safety issues. It can improve patients’ postoperative clinical outcome.     

Five-year follow-up of total disc replacement compared to fusion: a randomized controlled trial

Purpose

To evaluate long-term clinical results of lumbar total disc replacement (TDR) compared with posterior lumbar fusion.

Methods

This prospective randomized controlled trial comprised 152 patients; 80 were randomized to TDR and 72 to fusion. All patients had chronic low back pain (CLBP) and had not responded to nonsurgical treatment. Primary outcome measure was global assessment of back pain (GA), secondary outcome measures were back and leg pain, Oswestry Disability Index (ODI), EQ5D, and SF-36. All measures were collected from SweSpine (Swedish national register for spinal surgery) at 1, 2, and 5 years. Follow-up rate at 5 years was 99.3 %.

Results

Both groups showed clinical improvement at 5-year follow-up. For GA, 38 % (30/80) in the TDR group were totally pain free vs. 15 % (11/71) in the fusion group (p < 0.003). Back pain and improvement of back pain were better in the TDR group: VAS back pain at 5 years 23 ± 29 vs. 31 ± 27, p = 0.009, and VAS improvement of back pain at 5 years 40 ± 32 vs. 28 ± 32, p = 0.022. ODI and improvement in ODI were also better in the TDR group: ODI at 5 years 17 ± 19 vs. 23 + 17, p = 0.02 and ODI improvement at 5 years 25 ± 18 vs. 18 ± 19 (p = 0.02). There was no difference in complications and reoperations between the two groups.

Conclusions

Global assessment of low back pain differed between the two surgical groups at all follow-up occasions. Significant differences between groups concerning back pain, pain improvement, and ODI were present at 1 year and disappeared at 2 years, but reappeared at the 5-year follow-up.     

Should age be a contraindication for degenerative lumbar surgery?

Introduction and purpose

The purpose of this study was to evaluate and compare disability, quality of life and satisfaction outcomes between young people and elderly who were operated on for degenerative lumbar disease.

Material and methods

A database of 263 patients undergoing lumbar surgery for degenerative conditions was collected. There were 74 patients who were 65 years old or above and 189 who were below 65 who had complete preoperative and 2-year postoperative HRQOL data measures: ODI, SF-36 and COMI.

Results

There were no significant differences in the outcomes between the two age groups (p > 0.05). An improvement from baseline in all quality of life measures in the two age groups was observed. A median improvement of 6.0 points was found in the ODI in the younger patients versus 12.0 in older ones. A median improvement in the SF36 physical component score of 6.95 was seen in the younger group while improvement was reported at 6.36 points in patients over 65. The SF36 mental component score improved by 4.48 points and 4.96 points, respectively. COMI improved a median of 1.2 points in both groups. In terms of satisfaction, 66.9 % of the younger patients were pleased or very pleased whereas this was found to be 59.7 % for the older group.

Conclusion

Older patients can see substantial clinical improvement after degenerative lumbar disease surgery similar to that obtained in younger patients in terms of quality of life and satisfaction. The improvement in terms of the disability is greater for older patients. Thus, age should not be a contraindication for this procedure.     

Comparison between patient and surgeon perception of degenerative spine disease outcomes—a prospective blinded database study

Background

Few have studied the correlation between patients’ and spine surgeons’ perception on outcomes, or compared these with patient-reported outcome scores. Outcomes studies are increasingly important in evaluating costs and benefits to patients and surgeons, and in developing metrics for payer evaluation and health care policy-making.

Objective

To compare patients’ and surgeons’ assessment of spine treatment outcome in a prospective blinded patient-driven spine surgery outcomes registry, and to correlate perceived outcomes ratings to validated outcomes scores.

Methods

Patients filled out surveys at baseline, 3 months and 6 months postoperatively, including Visual Analog Scale (VAS), and Neck Disability Index (NDI) or Oswestry Disability Index (ODI). Outcome was rated independently by patients and surgeons on a 7-point Likert-type scale.

Results

Two-hundred and sixty-five consecutive adult patients were surgical candidates. Of these, 154 (58.1 %) opted for surgery, with 69 (44.8 %) cervical and 85 (55.2 %) lumbar patients. One hundred and thirty-five (87.7 %) had both patient and surgeon postoperative ratings. Surgeons’ and patients’ ratings correlated strongly (Spearman rho?=?0.53, p?<?0.0001, 45.9 % identical, 88.2 % +/? 1 grade). The surgeon rated outcomes were better than patients in 29.8 % and worse in 21.15 %. Patient rating correlated better with the most recent NDI/ODI and pain scores than with incremental change from baseline. In multivariate analysis, age, location (cervical vs lumbar), pain ratings, and functional scores (NDI, ODI) did not have significant impact on the discrepancy between patient and surgeon ratings.

Conclusions

Patients’ and surgeons’ global outcome ratings for spinal disease correlate highly. Patients’ ratings correlate better with most recent functional scores, rather than incremental change from baseline.     

Coexisting lumbar and cervical stenosis (tandem spinal stenosis): an infrequent presentation. Retrospective analysis of single-stage surgery (53 cases)

Study design

Retrospective analysis of 53 patients who underwent single stage simultaneous surgery for tandem spinal stenosis (TSS) at single centre.

Objective

To discuss the presentation of combined cervical and lumbar (tandem) stenosis and to evaluate the safety and efficacy of single-stage simultaneous surgery.

Summary of background data

Combined stenosis is an infrequent presentation with mixed presentation of upper motor neuron and lower motor neuron signs. Scarce literature on its presentation and management is available. There is a controversy in the surgical strategy of these patients. Staged surgeries are frequently recommended and only few single-stage surgeries reported.

Methods

All the patients were clinico-radiologically diagnosed TSS. Surgeries were performed in single stage by two teams. Results were evaluated with Nurick grade, modified Japanese Orthopedic Association score (mJOA), oswestry disability index (ODI), patient satisfaction index, mJOA recovery rate, blood loss and complication.

Results

The mJOA cervical and ODI score improved from a mean 8.86 and 68.15 preoperatively to 13.00 and 30.11, respectively, at 12 months and to 14.52 and 24.03 at final follow-up. The average mJOA recovery rate was 48.23 ± 26.90 %. Patient satisfaction index was 2.13 ± 0.91 at final follow-up. Estimated blood loss of ≤400 ml and operating room time of <150 min showed improvement of scores and lessened the complications. In the age group below 60 years, the improvement was statistically significant in ODI (p = 0.02) and Nurick’s grade (p = 0.03) with average improvement in mJOA score.

Conclusion

Short-lasting surgery, single anaesthesia, reduced morbidity and hospital stay as well as costs, an early return to function, high patient satisfaction rate with encouraging results justify single-stage surgery in TSS. Age, blood loss and duration of surgery decide the complication rate and outcome of surgery. Staged surgery is recommended in patients above the age of 60 years.     

Outcomes of posterior facet versus pedicle screw fixation of circumferential fusion: a cohort study

Purpose

To compare single-level circumferential spinal fusion using pedicle (n = 27) versus low-profile minimally invasive facet screw (n = 35) posterior instrumentation.

Method

A prospective two-arm cohort study with 5-year outcomes as follow-up was conducted. Assessment included back and leg pain, pain drawing, Oswestry disability index (ODI), pain medication usage, self-assessment of procedure success, and >1-year postoperative lumbar magnetic resonance imaging.

Results

Significantly less operative time, estimated blood loss and costs were incurred for the facet group. Clinical improvement was significant for both groups (p < 0.01 for all outcomes scales). Outcomes were significantly better for back pain and ODI for the facet relative to the pedicle group at follow-up periods >1 year (p < 0.05). Postoperative magnetic resonance imaging found that 20 % had progressive adjacent disc degeneration, and posterior muscle changes tended to be greater for the pedicle screw group.

Conclusion

One-level circumferential spinal fusion using facet screws proved superior to pedicle screw instrumentation.     

Clinical outcomes following sublaminar-trimming laminoplasty for extensive lumbar canal stenosis

Purpose

Current surgical approaches for treatment of lumbar canal stenosis are often associated with relatively high rates of reoperation and recurrent stenosis. We have developed a new approach for treatment of this condition: sublaminar-trimming laminoplasty. To describe the surgical approach of sublaminar-trimming laminoplasty and to assess associated outcomes.

Methods

Patients with extensive lumbar canal stenosis who received sublaminar-trimming laminoplasty from 2006 to 2008 were considered for inclusion in the study. The surgery comprised aspects of laminotomy and laminectomy. The following were assessed before surgery and 3 years after surgery: leg and back pain by visual analog scale (VAS), extent of disability by Oswestry Disability Index (ODI), severity of back pain by Japanese Orthopedic Association Score for Back Pain (JOA), walking tolerance, and leg numbness. Complications were noted.

Results

A total of 49 patients were included in the study (mean age 65.6 ± 10.6 years). VAS leg and back pain, ODI, and JOA scores significantly changed from before surgery to 3 years after surgery (P < 0.001). Mean changes (95 % confidence interval) were ?6.2 (?6.7, ?5.7), ?4.3 (?4.8, ?3.8), ?21.4 (?23.4, ?19.5), and 13.4 (12.1, 14.7) for leg pain, back pain, ODI, and JOA scores, respectively. Patients experienced significant improvements in walking tolerance and leg numbness (P < 0.001). There were no instances of recurrent stenosis or postoperative spinal instability. Complications included intraoperative dural tear (n = 2), postoperative urinary tract infection (n = 2), and inadequate decompression and junctional stenosis during follow-up (both n = 1).

Conclusion

Sublaminar-trimming laminoplasty shows promise as an effective treatment for extensive lumbar canal stenosis.     

Does pre-operative magnetic resonance imaging of the lumbar multifidus muscle predict clinical outcomes following lumbar spinal decompression for symptomatic spinal stenosis?

Purpose

To investigate whether pre-operative magnetic resonance imaging (MRI) of the lumbar multifidus muscle (LMM) would predict clinical outcomes following lumbar spinal decompression for symptomatic spinal stenosis.

Methods

A prospective cohort of patients with symptomatic neurogenic claudication, documented spinal stenosis on pre-operative MRI underwent spinal decompression. All subjects completed standardised outcome measures (Core Outcome Measures Index (COMI), Oswestry Disability Index (ODI v2.1) pre-operatively, 1 and 2 years post-surgery. Surgery was performed using a standardised lumbar spinous process osteotomy for access, followed by a decompression of the central canal, lateral recess and foraminal zones as indicated by the pre-operative MRI. Lumbar MRI scans were evaluated by two independent observers who assessed the axial CSA of the LMM bilaterally and the degree of muscle atrophy according to the Kader classification (2000). Changes in COMI and ODI scores at 1 and 2 years were investigated for statistically significant correlations with CSA of LMM and Kader grading. Statistical analyses utilised Student’s t test, kappa coefficient for inter-observer agreement and Bland–Altman Limits of Agreement (BALOA).

Results

66 patients (41 female) aged between 29 and 86 years underwent single-level decompression in 44, two-level decompression in 16 and three-level decompression in 6 cases. No significant correlation was observed between improvements in ODI and COMI relative to age, degree of stenosis, posterior fat thickness or psoas CSA. Those subjects with the greatest LMM atrophy relative to psoas CSA and L5 vertebral body area on pre-operative MRI had the least absolute improvement in both ODI and COMI scores (p = 0.006).

Conclusions

Reduced LMM CSA (<8.5 cm²) and muscle atrophy were associated with less favourable outcomes following lumbar spinal decompression. Pre-operative CSA of LMM appeared to be a more reliable predictor of post-operative clinical outcomes compared to the Kader Grading Score. This is the first study to investigate the prognostic value of pre-operative MRI appearance and CSA of LMM with respect to post-operative outcome following lumbar decompression surgery. Healthy pre-operative LMM is associated with better outcomes following lumbar spinal decompression.

     

The clinical and radiological outcomes of multilevel minimally invasive transforaminal lumbar interbody fusion

Purpose

To investigate the clinical and radiological outcomes of multilevel minimally invasive transforaminal lumbar interbody fusion (MITLIF) in multilevel degenerative lumbar diseases.

Methods

Of 172 patients who could be followed-up for at least 1 year after undergoing a MITLIF, a total of 127 patients in whom unilateral cages were used through a unilateral approach (consisting of 69 patients for single-level, 40 for two-level, and 18 for three- or higher-level) were retrospectively studied as subjects. In this study, clinical assessment parameters included Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI), while radiologic assessment parameters included disc height, segmental lordotic angle, and lumbar lordotic angle. At the last follow-up, the level of bone fusion was determined in accordance with the Brantigan and Steffee criteria for classification of fusion results.

Results

The VAS scores of back pain and radiating leg pain tended to improve postoperatively, and showed no significant difference among groups (p > 0.05). In terms of ODI, the results of functional assessments also indicated no significant difference among groups (p > 0.05). Similarly, there was no statistically significant difference in disc height, segmental lordotic angle, lumbar lordotic angle, and bone fusion depending on the number of fusion levels (p > 0.05).

Conclusions

Regardless of the number of fused levels, satisfactory clinical and radiological outcomes of MITLIF were seen in patients with spinal stenosis, which suggests that the said surgical procedure may be useful even for patients with multilevel spinal stenosis.     

Unilateral versus bilateral fixation for lumbar spinal fusion: a systemic review and meta-analysis

Purpose

The objective of this study was to systematically compare the efficacy and safety of unilateral fixation to bilateral fixation for the lumbar degenerative disease.

Study design

Systematic review and meta-analysis.

Methods

We searched databases including PubMed Central, MEDLINE (from 1966), EMBASE (from 1980), and Cochrane Central Register of Controlled Trials databases for randomized controlled trials or non-randomized controlled trials that compare unilateral fixation with bilateral fixation for the treatment for lumbar disease. Exclusion criteria were non-controlled studies, follow-up <6 months, combined anterior and posterior surgery, lumbar tumors, and non-English writing paper. Methodologic quality was assessed, relevant data were retrieved, and the appropriate meta-analysis was performed. Two review authors independently selected studies, extracted data, and assessed the risk of bias. The main end points included the rate of fusion, visual analogue scale (VAS), Oswestry disability index (ODI), intra-operative blood loss, operating time, and the rate of complications.

Results

A total of seven studies were included in the meta-analysis. Four relevant randomized controlled trials, one prospective study, and two retrospective studies involving 499 patients were identified. Patients in unilateral pedicle fixation group compared with bilateral pedicle screw fixation group on the fusion rate, VAS, ODI scores, and complication rate demonstrated no significant differences (P > 0.05, respectively). However, intra-operative blood loss and operating time in unilateral fixation group were significantly less than bilateral fixation group (P < 0.0001, respectively).

Conclusions

Unilateral fixation seems to be an effective, feasible, and safe procedure in one or two segmental disease when compare with bilateral instrumentation.     

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.     

The use of beta-tricalcium phosphate and bone marrow aspirate as a bone graft substitute in posterior lumbar interbody fusion

Purpose

Due to the disadvantages of iliac crest bone and the poor bone quality of autograft gained from decompression surgery, alternative filling materials for posterior lumbar interbody fusion cages have been developed. β-Tricalcium phosphate is widely used in cages. However, data regarding the fusion rate of β-TCP assessed by computer tomography are currently not available.

Materials

A prospective clinical trial involving 34 patients (56.7 years) was performed: 26 patients were treated with single-level, five patients double-level and three patients triple-level PLIF filled with β-TCP and bone marrow aspirate perfusion, and additional posterior pedicle screw fixation. Fusion was assessed by CT and X-rays 1 year after surgery using a validated fusion scale published previously. Functional status was evaluated with the visual analogue scale and the Oswestry Disability Index before and 1 year after surgery.

Results

Forty-five levels in 34 patients were evaluated by CT and X-ray with a follow-up period of at least 1 year. Clinically, the average ODI and VAS for leg and back scores improved significantly (P < 0.001). CT assessment revealed solid fusion in 12 levels (26.67 %) and indeterminate fusion in 15 levels (34.09 %). Inadequate fusion (non-union) was detected in 17 levels (38.63 %).

Conclusion

The technique of PLIF using β-TCP yielded a good clinical outcome 1 year after surgery, however, a high rate of pseudoarthrosis was found in this series therefore, we do not recommend β-TCP as a bone graft substitute using the PLIF technique.     

Reversibility of nerve root sedimentation sign in lumbar spinal stenosis patients after decompression surgery

Purpose

The nerve root sedimentation sign (SedSign) is a magnetic resonance imaging (MRI) sign for the diagnosis of lumbar spinal stenosis (LSS). It is included in the assessment of LSS to help determine whether decompression surgery is indicated. Assessment of the reversibility of the SedSign after surgery may also have clinical implications for the decision about whether or not a secondary operation or revision is needed. This study investigated if lumbar decompression leads to a reversal of the SedSign in patients with LSS and a positive SedSign pre-operatively; and if a reversal is associated with more favourable clinical outcomes. If reversal of the SedSign is usual after sufficient decompression surgery, a new positive SedSign could be used as an indicator of new stenosis in previously operated patients.

Methods

A prospective cohort study of 30 LSS patients with a positive pre-operative SedSign undergoing decompression surgery with or without instrumented fusion was undertaken to assess the presence of nerve root sedimentation (=negative SedSign) on MRI at 3 months post-operation. Functional limitation (Oswestry Disability Index, ODI), back and leg pain (Visual Analogue Scale, VAS), and treadmill walking distance were also compared pre- and 3 months post-operatively. The short follow-up period was chosen to exclude adjacent segment disease and the potential influence of surgical technique on clinical outcomes at longer follow-up times.

Results

30 patients [median age 73 years (interquartile range (IQR) 65–79), 16 males] showed a median pre-operative ODI of 66 (IQR 52–78), a median VAS of 8 (IQR 7–9), and a median walking distance of 0 m (IQR 0–100). Three months post-operation 27 patients had a negative SedSign. In this group, we found improved clinical outcomes at follow-up: median post-operative ODI of 21 (IQR 12–26), median VAS of 2 (IQR 2–4), and median walking distance of 1000 m (IQR 500–1000). These changes were all statistically significant (p < 0.001). Three patients had a positive SedSign at 3-month follow-up due to epidural fat (n = 2) or a dural cyst following an intra-operative dural tear (n = 1), but also showed improvements in clinical outcomes for ODI, VAS and walking distance.

Conclusion

The reversibility of a pre-operative positive SedSign was demonstrated after decompression of the affected segmental level and associated with an improved clinical outcome. A persisting positive SedSign could be the result of incomplete decompression or surgical complications. A new positive SedSign after sufficient decompression surgery could be used as an indicator of new stenosis in previously operated patients.