Two-year radiographic and clinical outcomes of a minimally invasive, lateral, transpsoas approach for anterior lumbar interbody fusion in the treatment of adult degenerative scoliosis

Predicting adequate segmental lordosis correction in lumbar spinal stenosis patients undergoing oblique lumbar interbody fusion: a focus on the discontinuous segment

PURPOSE

To identify the factors associated with a correction of the segmental angle (SA) with a total change greater than 10° in each level following minimally invasive oblique lumbar interbody fusion (MIS-OLIF).

METHODS

Patients with lumbar spinal stenosis who underwent single- or two-level MIS-OLIF were reviewed. Segments with adequate correction of the SA >10° after MIS-OLIF in immediate postoperative radiograph were categorized as discontinuous segments (D segments), whereas those without such improvement were assigned as continuous segments (C segments). Clinical and radiological parameters were compared, and multivariate logistic regression analysis was performed to identify factors associated with SA correction >10° after MIS-OLIF.

RESULTS

Of 211 segments included, 38 segments (18.0%) were classified as D segments. Compared with C segments, D segments demonstrated a significantly smaller preoperative SA (mean ± standard deviation [SD], - 1.1° ± 6.7° vs. 6.6° ± 6.3°, p < 0.001), larger change of SA (mean ± SD, 13.5° ± 3.4° vs. 3.1° ± 3.9°, p < 0.001), and a higher rate of presence of facet effusion (76.3% vs. 48.6%, p = 0.002). Logistic regression revealed preoperative SA (odds ratio (OR) [95% confidence interval (CI)]:0.733 [0.639-0.840], p < 0.001) and facet effusion (OR [95% CI]:14.054 [1.758-112.377], p = 0.027) as significant predictors for >10° SA correction after MIS-OLIF.

CONCLUSION

Preoperative kyphotic SA and facet effusion can predict SA correction >10° following MIS-OLIF. For patients with lordotic SA and no preoperative facet effusion, supplemental procedures, such as anterior column release or posterior osteotomy, should be prepared for additional lumbar lordosis correction required for remnant global sagittal imbalance after MIS-OLIF.

Long-term Outcomes of Minimally Invasive Lateral Lumbar Interbody Fusion in the Treatment of Adult Scoliosis

The literature has shown the importance of long-term follow-up for adults with scoliosis treated surgically because complication and revision rates are high. The goal of this study was to determine long-term outcomes and complications of lateral lumbar interbody fusion (LLIF) with posterior instrumentation for adult patients with scoliosis. A retrospective review of our institution's database was performed to identify adult patients with scoliosis treated with LLIF between 2008 and 2013 with a minimum follow-up of 4 years. Medical records were reviewed for complications and revisions. Pre- and postoperative deformity Cobb angle measurements were taken as well as pelvic incidence (PI) and lumbar lordosis (LL). Functional outcome scores, including Oswestry Disability Index and visual analog scale score for back and leg pain, were assessed preoperatively and at follow-up. Standard binomial and categorical comparative analysis was performed. The 26 patients included had a mean age of 62 years, mean follow-up of 89 months, and mean of 1.8 levels per operation. Four patients (15.4%) required revisions. Mean deformity Cobb angle was 26° preoperatively and 14° postoperatively. Mean PI-LL mismatch was 11.7° preoperatively and 5.9° postoperatively. Nineteen (73%) patients had a PI-LL mismatch greater than 10° preoperatively, whereas only 2 (7.7%) had a mismatch postoperatively. Improvement was seen in all functional outcome scores. Long-term clinical results of LLIF for adults with deformity showed a low proportion of revision in the treatment of a condition with an established high rate of revision. The ability to reduce pelvic mismatch may further reduce the rate of revision. In this study, LLIF resulted in improved functional outcomes and patient satisfaction. [Orthopedics. 2022;45(3):e134-e139.].

Complications of adult spinal deformity surgery: A literature review

Purpose:

Adult spinal deformity incidence increases accordingly as the population ages. Even though surgery is the best option for the treatment, the complications due to surgery are pretty challenging. This study aims to review the complication rates of adult spinal deformity surgery.

Methods:

A literature review of the last decade was performed searching for the query “Adult spine deformity and complication.” This search yielded 2781 results, where 79 articles were chosen to investigate the complications of adult spinal deformity surgery. In addition, the demographic data, surgical interventions, and complications were extracted from the publications.

Results:

A total of 26,207 patients were analyzed, and 9138 complications were found (34.5%). Implant failure, including screw loosening, breakage, distal and proximal junctional kyphosis, were the most common complications. The neurologic complications were about 10.8%, and the infection rate was 3.6%. Cardiac and pulmonary complications were about 4.8%.

Discussion:

Age, body mass index, smoking, osteoporosis, and other comorbidities are the significant risk factors affecting adult spinal deformity surgery. Presurgical planning and preoperative risk factor assessment must be done to avoid complications. Furthermore, intra and postoperative complications affect the patients’ quality of life and length of stay, and hospital readmissions. Revision surgery also increases the risk of complications.

Conclusion:

Good patient evaluation before surgery and careful planning of the surgery are essential in avoiding complications of adult spinal deformity.

Development and Initial Internal Validation of a Novel Classification System for Perioperative Expectations Following Minimally Invasive Degenerative Lumbar Spine Surgery

STUDY DESIGN

This was a prospective consecutive clinical cohort study.

OBJECTIVE

The purpose of our study was to develop and provide an initial internal validation of a novel classification system that can help surgeons and patients better understand their postoperative course following the particular minimally invasive surgery (MIS) and approach that is utilized.

SUMMARY OF BACKGROUND DATA

Surgeons and patients are often attracted to the option of minimally invasive spine surgery because of the perceived improvement in recovery time and postsurgical pain. A classification system based on the impact of the surgery and surgical approach(es) on postoperative recovery can be particularly helpful.

METHODS

Six hundred thirty-one patients who underwent MIS lumbar/thoracolumbar surgery for degenerative conditions of the spine were included. Perioperative outcomes-operative time, estimated blood loss, postsurgical length of stay (LOS), 90-day complications, postoperative day zero narcotic requirement [in Morphine Milligram Equivalent (MME)], and need for intravenous patient-controlled analgesia (IV PCA).

RESULTS

Postoperative LOS and postoperative narcotic use were deemed most clinically relevant, thus selected as primary outcomes. Type of surgery was significantly associated with all outcomes (P<0.0001), except intraoperative complications. Number of levels for fusion was significantly associated with operative time, in-hospital complications, 24 hours oral MME, and the need for IV PCA and LOS (P<0.0001). Number of surgical approaches for lumbar fusion was significantly associated with operative time, 24 hours oral MME, need for IV PCA and LOS (P<0.001). Based on these parameters, the following classification system ("Qureshi-Louie classification" for MIS degenerative lumbar surgery) was devised: (1) Decompression-only; (2) Fusion-1 and 2 levels, 1 approach; (3) Fusion-1 level, 2 approaches; (4) Fusion-2 levels, 2 approaches; (5) Fusion-3+ levels, 2 approaches.

CONCLUSIONS

We present a novel classification system and initial internal validation to describe the perioperative expectations following various MIS surgeries in the degenerative lumbar spine. This initial description serves as the basis for ongoing external validation.

Improvements in Back and Leg Pain Following a Minimally Invasive Transforaminal Lumbar Interbody Fusion

BACKGROUND

Improvement in patient-reported outcomes after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is poorly defined. As such, the purpose of this study was to quantify improvements in Visual Analogue Scale back and leg pain, Oswestry Disability Index (ODI), and Short Form-12 (SF-12) Mental and Physical Composite scores following MIS-TLIF.

METHODS

A surgical registry of patients who underwent primary 1-level MIS-TLIF during 2014-2015 was reviewed. Comparisons of Visual Analogue Scale back and leg pain, ODI, and Short Form-12 Mental and Physical Composite scores were performed using paired t tests from preoperative to each postoperative time point. Analysis of variance was used to estimate the degree of improvement in back and leg pain over the first postoperative year. Subgroup analysis was performed for patients presenting with predominant back (pBP) or leg (pLP) pain. Multivariate linear regression was performed to compare patient-reported outcome scores by subgroup.

RESULTS

A total of 106 patients were identified. Visual Analogue Scale back and leg scores, and ODI improved from preoperative scores at all postoperative time points (P < .05 for each). Patients with pBP (n = 68) and patients with pLP (n = 38) reported reductions in both back and leg pain over the first postoperative year (P < .05 for each). In the pBP cohort, patients experienced significant reductions in ODI after the first 6 postoperative weeks (P < .05 for each). In the pLP cohort, patients experienced significant reductions in ODI throughout the first postoperative year (P < .05 for each). Patients with pLP and pBP experienced similar reductions in back pain, whereas patients with pLP experienced significantly greater reductions in leg pain at all postoperative time points (P < .05 for each).

CONCLUSIONS

The current study suggests patients experience significant improvements in back and leg pain following MIS-TLIF regardless of predominant symptom.

CLINICAL RELEVANCE

These results can assist surgeons when counseling their patients on the magnitude of symptom improvement they may experience following MIS-TLIF.

Minimally invasive surgery versus standard posterior approach for Lenke Type 1-4 adolescent idiopathic scoliosis: a multicenter, retrospective study

PURPOSE

To compare the safety and efficacy of posterior minimally invasive surgery (MIS) to standard posterior spinal fusion (PSF) surgery for Lenke Type 1-4 adolescent idiopathic scoliosis (AIS).

METHODS

This multicenter retrospective study enrolled 112 patients with Lenke Type 1-4 AIS who treated with MIS (n = 64) or PSF (n = 48) between March 2007 and January 2015. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. Operative time, level of fusion, intraoperative blood loss, blood transfusion, and intraoperative radiation exposure were recorded. 22-item Scoliosis Research Society questionnaire (SRS-22) was applied for assessment of life quality. The accuracy of pedicle screw placement was assessed according to postoperative computed tomography images, and the complications were collected in follow-up period.

RESULTS

The baseline characteristics of 2 groups were matched. There was no significant difference between 2 groups in terms of radiographic parameters immediately after surgery and at the last follow-up. The MIS group had significantly longer operative time, more level of fusion, less intraoperative blood loss, and lower blood transfusion rate (p < 0.001). The evaluation of pain using SRS-22 showed significantly lower score in MIS group (p < 0.05). No significant difference was found between 2 groups in terms of accuracy of pedicle screw placement and complications.

CONCLUSION

Posterior MIS is a safe and effective alternative to standard open approach for Lenke Type 1-4 AIS patients with curves < 70° and reasonable flexibility. Mid-term results showed MIS had the advantages of less blood loss and pain with more fusion segments.

Analysis of the Factors Affecting Lumbar Segmental Lordosis After Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

To elucidate factors that determine segmental lordosis after lateral retroperitoneal lumbar interbody fusion (LLIF) with percutaneous pedicle screw fixation.

SUMMARY OF BACKGROUND DATA

LLIF has been widely used in degenerative lumbar spine surgery. However, the detailed mechanisms that determine segmental lordosis are still unknown.

METHODS

A total of 69 patients who underwent LLIF with posterior pedicle screw fixation without posterior osteotomy were analyzed. Computed tomography was performed before and within 2 weeks after surgery, and segmental lordotic angle (SLA) after surgery (Post-SLA) was predicted using multiple regression analysis. Explanatory factors considered in this study included SLA before surgery (Pre-SLA), disc height before surgery (DiscH), cage position (CageP; distance between the center of the cage and the center of the disc, where a positive value indicates an anterior cage position), cage angle (CageA), cage height (CageH), CageH-DiscH (amount of lift up), previous decompression surgery, and level fused.

RESULTS

A total of 102 levels were analyzed. Multiple regression analysis revealed that the Post-SLA can be predicted with three independent variables, CageP, Pre-SLA, and CageH-DiscH and the adjusted R was 0.70. In cases when the cage was located anteriorly (CageP > 3 mm), Post-SLA was greater with larger CageH, larger CageA, and larger Pre-SLA. When the cage was located in the middle (3 mm ≤CageP ≤-1 mm), Post-SLA was greater with larger CageP, larger Pre-SLA, and without previous decompression surgery. If the cage was located posteriorly (CageP < -1 mm), Post-SLA was greater with smaller CageH-DiscH and greater Pre-SLA.

CONCLUSION

To gain maximum segmental lordosis in LLIF, the cage should be located anteriorly. Furthermore, if the cage can be located anteriorly, a thicker cage with proper angle cage will gain segmental lordosis. If the cage is located posteriorly, a thin cage should be selected.

LEVEL OF EVIDENCE

3.

Reduction in foraminal height after lateral access surgery does not affect quality of life: A 2-year outcome study on lateral lumbar interbody fusion

INTRODUCTION

Reduction in neuroforaminal height (FH) may diminish the indirect decompression benefit that lateral access surgery (LAS) provides. However, the relationship between postoperative FH reduction in LAS and health-related quality-of-life (HRQoL) outcomes remains unclear.

OBJECTIVES

To determine whether FH reduction affects HRQoL outcomes at 2-year follow-up.

METHODS

A retrospective review of 45 patients who underwent LAS for degenerative lumbar spine conditions was performed. The cohort was divided into two groups: maintenance (A) and reduction (B) in FH. Outcome measures included numerical pain rating scale (NPRS back and leg pain), Oswestry Disability Index (ODI), Short Form 36 Health Survey (SF-36), North American Spine Society (NASS) score for neurogenic symptoms (NS), patient satisfaction, and expectation fulfilment for surgery. Mean disc height (DH), FH, and fusion were evaluated on plain radiographs. Radiological fusion was assessed with the Bridwell fusion classification. Unpaired student's t-test was used to compare between groups and one-way ANOVA with Bonferroni post hoc correction was used to determine differences between time intervals within each group.

RESULTS

The average pre-op mean FH was 16.9 ± 3.5 mm. Group A had 25 patients showing postoperative maintenance of FH (19.4 ± 3.3 mm to 20.2 ± 3.2 mm; 4% increase) at 2-year postsurgery while group B had 20 patients showing decrease in FH (21.1 ± 3.3 mm to 18.7 ± 3.5 mm; 11% decrease). Group A mean DH improved from 7.0 ± 2.0 mm to 10.3 ± 1.6 mm (47% increase). Group B mean DH improved from 6.8 ± 2.3 mm to 11.0 ± 3.0 mm (62% increase). There were no significant differences in NPRS, ODI, NASS, SF-36, and SF-36 MCS/PCS between groups at 2 years ( p > 0.05); 92% of group A and 85% of group B patients reported good satisfaction and fulfilment of expectations ( p > 0.05).

CONCLUSION

Despite an initial increase in FH after LAS surgery, 45% of patients had FH reduction at 2 years. However, FH reduction up to 11% did not affect short-term HRQoL outcomes.

Improvements in Back and Leg Pain After Minimally Invasive Lumbar Decompression

BACKGROUND

Few studies have quantified clinical improvement following minimally invasive lumbar decompression based on predominant back pain or leg pain.

PURPOSE

To quantify improvement in patient-reported outcomes following minimally invasive lumbar decompression and determine the degree of improvement in back pain, leg pain, and disability in patients who present with predominant back pain or predominant leg pain.

METHODS

Patients who underwent primary, one-level minimally invasive lumbar decompression for degenerative pathology were retrospectively reviewed. Comparisons of visual analog scale (VAS) back and leg pain scores, Oswestry Disability Index (ODI) scores, and Short Form-12 (SF-12) mental and physical component scores from pre-operative to 6-week, 12-week, 6-month, and 1-year follow-up. Subgroup analyses were performed for patients with predominant back pain or predominant leg pain.

RESULTS

A total of 102 patients were identified. Scores on VAS back and leg pain, ODI, and SF-12 physical component improved from pre-operative to all post-operative time points. After 1 year, patients reported a 2.8-point (47%) reduction in back pain and a 4-point (61.1%) reduction in leg pain scores; 52 patients with predominant back pain and 50 patients with predominant leg pain reported reductions in pain throughout the year following surgery. In both the back and leg pain cohorts, patients experienced reductions in ODI during the first 6 months and throughout 1-year follow-up, respectively. The majority of patients achieved minimum clinically important difference, regardless of predominant symptom.

CONCLUSIONS

Patients reported improvements in back and leg pain following minimally invasive lumbar decompression regardless of predominant presenting symptom; however, patients with predominant leg pain may experience greater improvement than those with predominant back pain.

Minimally invasive surgery for degenerative spondylolisthesis: transforaminal or oblique lumbar interbody fusion

Aim: To compare the outcomes of minimally invasive surgery (MIS) for degenerative spondylolisthesis transforaminal lumbar interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF). Materials & methods: The clinical and surgical characteristics and outcomes of 38 patients with MIS-OLIF and 55 with MIS-TLIF were retrospectively evaluated. Results: Procedures and hospital stay were shorter and blood loss was less, with MIS-OLIF than with MIS-OLIF. The clinical and radiographic outcomes were similar. Postoperative changes in disk height and foraminal dimension were greater and patient satisfaction was better with MIS-OLIF than with MIS-TLIF. Conclusion: The clinical findings associated with the two procedures were similar; but patients preferred MIS-OLIF, which is less invasive, to MIS-TLIF. Clinical trial registration number: ChiCTR1800019443.

[Effectiveness of nano-hydroxyapatite/polyamide-66 Cage in interbody fusion for degenerative lumbar scoliosis]

Objective

To explore the effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) Cage in interbody fusion for degenerative lumbar scoliosis.

Methods

A retrospective analysis was designed and conducted for 43 patients, who underwent posterior decompression and n-HA/PA66 Cage interbody fusion with correction of deformity between January 2013 and June 2016. Eighteen cases were single-level fusion (single-level group) and 25 cases were double-level fusion (double-level group). There was no significant difference in gender, age, body mass index, direction of convex, degree of apical rotation, fusion level, the number of osteoporotic patients, pre-operative intervertebral height of fusion segments, coronal Cobb angle, visual analogue score (VAS), and modified Oswestry Disability Index (ODI) between 2 groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stay, and complications of the operation were recorded. Modified ODI, VAS score, and MacNab criteria were adopted to assess clinical outcomes. Radiographic indexes, including intervertebral height of fusion segments, coronal Cobb angle, disc insertion depth, and the bone graft fusion rate, were also evaluated.

Results

There was no significant difference in operation time, intraoperative blood loss, postoperative drainage, and hospital stay between 2 groups ( P>0.05). All patients were followed up 18-62 months (mean, 30.9 months). Wound complications, postoperative delirium, and Cage retropulsion occurred in 4 cases (2 cases in single-level group, 2 cases in double-level group), 1 case of single-level group, and 1 case of double-level group, respectively. The intervertebral height of fusion segments after operation significantly improved compared with preoperative ones in both groups ( P<0.05). At last follow-up, the intervertebral height in double-level group was superior to which in single-level group ( P<0.05). The coronal Cobb angles after operation significantly improved compared with preoperative ones ( P<0.05), and no significant difference was found between 2 groups at each time point ( P>0.05). The disc insertion depth showed no significant difference between different time points after operation in 2 groups ( P>0.05) and between 2 groups at each time point after operation ( P>0.05). Bony fusion was obtained in all patients at last follow-up. The VAS score and modified ODI after operation in both groups were superior to those before operation ( P<0.05). The VAS score in double-level group was higher than that in single-level group ( P<0.05) at last follow-up, and no significant difference was found in VAS score and modified ODI between 2 groups at other time points ( P>0.05). According to the MacNab criteria, the excellent and good rates at last follow-up were 94.4% and 84.0% in single-level group and double-level group, respectively.

Conclusion

The n-HA/PA66 Cage can effectively restore and maintain the disc height of fusion segment, normal sequence, and biomechanical stability of the spine, and gain favorable effectivenss for degenerative lumbar scoliosis. And double-level fusion is superior to single-level fusion in maintaining disc height of fusion segment.

Complications for minimally invasive lateral interbody arthrodesis: a systematic review and meta-analysis comparing prepsoas and transpsoas approaches

OBJECTIVE

Minimally invasive anterolateral retroperitoneal approaches for lumbar interbody arthrodesis have distinct advantages attractive to spine surgeons. Prepsoas or transpsoas trajectories can be employed with differing complication profiles because of the inherent anatomical differences encountered in each approach. The evidence comparing them remains limited because of poor quality data. Here, the authors sought to systematically review the available literature and perform a meta-analysis comparing the two techniques.

METHODS

A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A database search was used to identify eligible studies. Prepsoas and transpsoas studies were compiled, and each study was assessed for inclusion criteria. Complication rates were recorded and compared between approach groups. Studies incorporating an analysis of postoperative subsidence and pseudarthrosis rates were also assessed and compared.

RESULTS

For the prepsoas studies, 20 studies for the complications analysis and 8 studies for the pseudarthrosis outcomes analysis were included. For the transpsoas studies, 39 studies for the complications analysis and 19 studies for the pseudarthrosis outcomes analysis were included. For the complications analysis, 1874 patients treated via the prepsoas approach and 4607 treated with the transpsoas approach were included. In the transpsoas group, there was a higher rate of transient sensory symptoms (21.7% vs 8.7%, p = 0.002), transient hip flexor weakness (19.7% vs 5.7%, p < 0.001), and permanent neurological weakness (2.8% vs 1.0%, p = 0.005). A higher rate of sympathetic nerve injury was seen in the prepsoas group (5.4% vs 0.0%, p = 0.03). Of the nonneurological complications, major vascular injury was significantly higher in the prepsoas approach (1.8% vs 0.4%, p = 0.01). There was no difference in urological or peritoneal/bowel injury, postoperative ileus, or hematomas (all p > 0.05). A higher infection rate was noted for the transpsoas group (3.1% vs 1.1%, p = 0.01). With regard to postoperative fusion outcomes, similar rates of subsidence (12.2% prepsoas vs 13.8% transpsoas, p = 0.78) and pseudarthrosis (9.9% vs 7.5%, respectively, p = 0.57) were seen between the groups at the last follow-up.

CONCLUSIONS

Complication rates vary for the prepsoas and transpsoas approaches owing to the variable retroperitoneal anatomy encountered during surgical dissection. While the risks of a lasting motor deficit and transient sensory disturbances are higher for the transpsoas approach, there is a reciprocal reduction in the risks of major vascular injury and sympathetic nerve injury. These results can facilitate informed decision-making and tailored surgical planning regarding the choice of minimally invasive anterolateral access to the spine.

Does approach matter? A comparative radiographic analysis of spinopelvic parameters in single-level lumbar fusion

BACKGROUND CONTEXT

Lumbar fusion is a popular and effective surgical option to provide stability and restore anatomy. Particular attention has recently been focused on sagittal alignment and radiographic spinopelvic parameters that apply to lumbar fusion as well as spinal deformity cases. Current literature has demonstrated the effectiveness of various techniques of lumbar fusion; however, comparative data of these techniques are limited.

PURPOSE

This study aimed to directly compare the impact of various lumbar fusion techniques (anterior lumbar interbody fusion [ALIF], lateral lumbar interbody fusion [LLIF], transforaminal lumbar interbody fusion [TLIF], and posterolateral fusion [PLF]) based on radiographic parameters.

STUDY DESIGN/SETTING

A single-center retrospective study examining preoperative and postoperative radiographs was carried out.

PATIENT SAMPLE

A consecutive list of lumbar fusion surgeries performed by multiple spine surgeons at a single institution from 2013 to 2016 was identified.

OUTCOME MEASURES

Radiographic measurements used included segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence (PI), pelvic incidence-lumbar lordosis (PI-LL) mismatch, anterior and posterior disc height (DH-A, DH-P, respectively), and foraminal height (FH).

METHODS

Radiographic measurements were performed on preoperative and postoperative lateral lumbar radiographs on all single-level lumbar fusion cases. Demographic data were collected including age, gender, approach, diagnosis, surgical level, and implant lordosis. Paired sample t test, one-way analysis of variance (ANOVA), McNemar test, and independent sample t test were used to establish significant differences in the outcome measures. Multiple linear regression was performed to determine a predictive model for lordosis from implant lordosis, fusion technique, and surgical level.

RESULTS

There were 164 patients (78 men, 86 women) with a mean age of 60.1 years and average radiographic follow-up time of 9.3 months. These included 34 ALIF, 23 LLIF, 63 TLIF, and 44 PLF surgeries. ALIF and LLIF significantly improved SL (7.9° and 4.4°), LL (5.5° and 7.7°), DH-A (8.8 mm and 5.8 mm), DH-P (3.4 mm and 2.3 mm), and FH (2.8 mm and 2.5 mm), respectively (p≤.003). TLIF significantly improved these parameters, albeit to a lesser extent: SL (1.7°), LL (2.7°), DH-A (1.1 mm), DH-P (0.8 mm), and FH (1.1 mm) (p≤.02). PLF did not significantly alter any of these parameters while significantly reducing FH (-1.3 mm, p=.01). One-way ANOVA showed no significant differences between ALIF and LLIF other than ALIF with greater ΔDH-A (3.0 mm, p=.02). Both ALIF and LLIF significantly outperformed PLF in preoperative to postoperative changes in all parameters p≤.001. Additionally, ALIF significantly outperformed TLIF in the change in SL (6.2°, p<.001), and LLIF significantly outperformed TLIF in the change in LL (5.0°, p=.02). Both outperformed TLIF in ΔDH-A (7.7 mm and 4.7 mm) and ΔDH-P (2.6 mm and 1.5 mm), respectively (p≤.02). ALIF was the only fusion technique that significantly improved the proportion of patients with a PI-LL<10° (0.410.66, p=.02). Lordotic cages had superior improvement of all parameters compared with non-lordotic cages (p<.001). Implant lordosis (m=1.1), fusion technique (m=6.8), and surgical level (m=6.9) significantly predicted postoperative SL (p<.001, R²=0.56).

CONCLUSIONS

This study demonstrated that these four lumbar fusion techniques yield divergent radiographic results. ALIF and LLIF produced greater improvements in radiographic measurements postoperatively compared with TLIF and PLF. ALIF was the most successful in improving PI-LL mismatch, an important parameter relating to sagittal alignment. Lordotic implants provided better sagittal correction and surgeons should be cognizant of the impact that these differing implants and techniques produce after surgery. Surgical technique is an important determinant of postoperative alignment and has ramifications upon sagittal alignment in lumbar fusion surgery.

Contribution of Lateral Interbody Fusion in Staged Correction of Adult Degenerative Scoliosis

Objective

Lateral interbody fusion (LIF) is attractive as a less invasive technique to address anterior spinal pathology in the treatment of adult spinal deformity. Its own uses and benefits in treatment of adult degenerative scoliosis are undefined. To investigate the radiographic and clinical outcomes of LIF, and staged LIF and posterior spinal fusion (PSF) for the treatment of adult degenerative scoliosis patients, we analyzed radiographic and clinical outcomes of adult degenerative scoliosis patients who underwent LIF and posterior spinal fusion.

Methods

Forty consecutive adult degenerative scoliosis patients who underwent LIF followed by staged PSF at a single institution were retrospectively reviewed. Long-standing 36” anterior-posterior and lateral radiographs were taken preoperatively, at inter-stage, 3 months, 1 year, and 2 years after surgery were reviewed. Outcomes were assessed through the visual analogue scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index (ODI).

Results

Forty patients with a mean age of 66.3 (range, 49–79) met inclusion criteria. A mean of 3.8 levels (range, 2–5) were fused using LIF, while a mean of 9.0 levels (range, 3–16) were fused during the posterior approach. The mean time between stages was 1.4 days (range, 1–6). The mean follow-up was 19.6 months. Lumbar lordosis was significantly restored from 36.4º preoperatively up to 48.9º (71.4% of total correction) after LIF and 53.9º after PSF. Lumbar coronal Cobb was prominently improved from 38.6º preoperatively to 24.1º (55.8% of total correction) after LIF, 12.6º after PSF respectively. The mean pelvic incidence-lumbar lordosis mismatch was markedly improved from 22.2º preoperatively to 8.1º (86.5% of total correction) after LIF, 5.9º after PSF. Correction of coronal imbalance and sagittal vertebral axis did not reach significance. The rate of perioperative complication was 37.5%. Five patients underwent revision surgery due to wound infection. No major perioperative medical complications occurred. At last follow-up, there were significant improvements in VAS, SF-36 Physical Component Summary and ODI scores.

Conclusion

LIF provides significant corrections in the coronal and sagittal plane in the patients with adult degenerative scoliosis. However, LIF combined with staged PSF provides more excellent radiographic and clinical outcomes, with reduced perioperative risk in the treatment of adult degenerative scoliosis.

Recent Advances in Technique and Clinical Outcomes of Minimally Invasive Spine Surgery in Adult Scoliosis

Objective:

Conventional open spinal surgery of adult scoliosis can be performed from anterior, posterior, or combined approach. Minimally invasive spine surgery (MISS) was developed for the purpose of reducing the undesirable effects and complications. This review aimed to make a brief summary of recent studies of the approach and clinical outcomes of MISS in adult scoliosis.

Data Sources:

We conducted a systematic search from PubMed, Medline, EMBASE, and other literature databases to collect reports of surgical methods and clinical outcomes of MISS in treatment of adult scoliosis. Those reports were published up to March 2017 with the following key terms: “minimally invasive,” “spine,” “surgery,” and “scoliosis.”

Study Selection:

The inclusion criteria of the articles were as followings: diagnosed with adult degenerative scoliosis (DS) or adult idiopathic scoliosis; underwent MISS or open surgery; with follow-up data. The articles involving patients with congenital scoliosis or unknown type were excluded and those without any follow-up data were also excluded from the study. The initial search yielded 233 articles. After title and abstract extraction, 29 English articles were selected for full-text review. Of those, 20 studies with 831 patients diagnosed with adult DS or adult idiopathic scoliosis were reviewed. Seventeen were retrospective studies, and three were prospective studies.

Results:

The surgical technique reported in these articles was direct or extreme lateral interbody fusion, axial lumbar interbody fusion, and transforaminal lumbar interbody fusion. Among the clinical outcomes of these studies, the operated levels was 3–7, operative time was 2.3–8.5 h. Both the Cobb angle of coronal major curve and evaluation of Oswestry Disability Index and Visual Analog Scale decreased after surgery. There were 323 complications reported in the 831 (38.9%) patients, including 150 (18.1%) motor or sensory deficits, and 111 (13.4%) implant-related complications.

Conclusions:

MISS can provide good radiological and self-evaluation improvement in treatment of adult scoliosis. More prospective studies will be needed before it is widely used.

Minimally invasive techniques for lumbar decompressions and fusions

PURPOSE OF REVIEW

The purpose of this study is to summarize the recent literature investigating the use of minimally invasive (MIS) techniques in the treatment of lumbar degenerative stenosis, spondylolisthesis, and scoliosis.

RECENT FINDINGS

MIS lumbar decompression and fusion techniques for degenerative pathology are associated with reduced operative morbidity, shortened length of hospital stay, and reduced postoperative pain and narcotics utilization. Recent studies with long-term clinical follow-up have demonstrated equivalence in clinical outcomes between open and MIS surgical procedures. Radiographically, MIS procedures provide adequate postoperative correction of coronal alignment. Correction of sagittal alignment, however, is more variable based on current reports. MIS techniques are both safe and effective in the treatment of lumbar degenerative pathologies. While some studies have reported on long-term outcomes and costs associated with MIS procedures, more investigation into these topics is still necessary. Additionally, further work is required to analyze the training requirements and learning curves of MIS procedures to better promote adoption amongst surgeons.

Correction of severe spinopelvic mismatch: decreased blood loss with lateral hyperlordotic interbody grafts as compared with pedicle subtraction osteotomy

OBJECTIVE

Pedicle subtraction osteotomy (PSO) provides extensive correction in patients with fixed sagittal plane imbalance but is associated with high estimated blood loss (EBL). Anterior column realignment (ACR) with lateral graft placement and sectioning of the anterior longitudinal ligament allows restoration of lumbar lordosis (LL). The authors compare peri- and postoperative measures in 2 groups of patients undergoing correction of a sagittal plane imbalance, either through PSO or the use of lateral lumbar fusion and ACR with hyperlordotic (20°–30°) interbody cages, with stabilization through standard posterior instrumentation in all cases.

METHODS

The authors performed a retrospective chart review of cases involving a lumbar PSO or lateral lumbar interbody fusion and ACR (LLIF-ACR) between 2010 and 2015 at the authors’ institution. Patients who had a PSO in the setting of a preexisting fusion that spanned more than 4 levels were excluded. Demographic characteristics, spinopelvic parameters, EBL, operative time, and LOS were analyzed and compared between patients treated with PSO and those treated with LLIF-ACR.

RESULTS

The PSO group included 14 patients and the LLIF-ACR group included 13 patients. The mean follow-up was 13 months in the LLIF-ACR group and 26 months in the PSO group. The mean EBL was significantly lower in the LLIF-ACR group, measuring approximately 50% of the mean EBL in the PSO group (1466 vs 2910 ml, p < 0.01). Total LL correction was equivalent between the 2 groups (35° in the PSO group, 31° in the LLIF-ACR group, p > 0.05), as was the preoperative PI-LL mismatch (33° in each group, p > 0.05) and the postoperative PI-LL mismatch (< 1° in each group, p = 0.05). The fusion rate as assessed by the need for reoperation due to pseudarthrosis was lower in the LLIF-ACR group but not significantly so (3 revisions in the PSO group due to pseudarthrosis vs 0 in the LLIF-ACR group, p > 0.5). The total operative time and LOS were not significantly different in the 2 groups.

CONCLUSIONS

This is the first direct comparison of the LLIF-ACR technique with the PSO in adult spinal deformity correction. The study demonstrates that the LLIF-ACR provides equivalent deformity correction with significantly reduced blood loss in patients with a previously unfused spine compared with the PSO. This technique provides a powerful means to avoid PSO in selected patients who require spinal deformity correction.

Adult spinal deformity: effectiveness of interbody lordotic cages to restore disc angle and spino-pelvic parameters through completely mini-invasive trans-psoas and hybrid approach

PURPOSE

The aim of the study is to assess and quantify the effectiveness of interbody lordotic cages applied by trans-psoas approach to improve radiographic parameters, showing the differences between completely mini-invasive and hybrid approach.

METHODS

We collected data of 65 patients affected by degenerative lumbar deformity/diseases and underwent mini-invasive lateral interbody fusion followed by percutaneous (group A, completely mini-invasive) or open (group B, hybrid) posterior instrumentation. A subgroup underwent anterior column realignment (ACR). We assessed statistical differences in preoperative and postoperative (at least 6-month) coronal and sagittal parameters, and disc angle (DA) at each level of cage application.

RESULTS

107 lordotic cages were implanted. Group B had the most significant mean changes, especially in coronal Cobb angle, sagittal vertical axis, lumbar lordosis (LL), pelvic incidence-LL mismatch and DA. Concerning DA, at each level of lordotic cage application, in group A changed from -2.9° preop to -6.5° postop (p = 0.01); in group B, DA changed from -2.6° to -9.5° (p = 0.002) and from +1° to -13.2° in patients underwent ACR.

CONCLUSIONS

Minimally invasive lateral lumbar interbody fusion is an effective technique in improving sagittal parameters. When combined with posterior open approach and/or application of ACR procedure greater corrections are possible.

Minimally invasive surgery in adult degenerative scoliosis: a systematic review and meta-analysis of decompression, anterior/lateral and posterior lumbar approaches

BACKGROUND

Minimally invasive approaches for the treatment of adult degenerative scoliosis have been increasingly implemented. However, little data exists regarding the safety and complication profiles of minimally invasive lumbar interbody fusion (LIF) for adult degenerative scoliosis. This study aimed to greater understand different minimally invasive surgical approaches for adult degenerative scoliosis with respect to clinical outcomes, changes in radiographic measurements, and complication profiles via meta-analytical techniques.

METHODS

A systematic search of six databases from inception to September 2015 was performed by two independent reviewers. Relevant studies were those that described the safety and/or effectiveness of minimally invasive anterior or lateral LIF (LLIF), transforaminal LIF (TLIF), and decompression only. Meta-analytical techniques and meta-regression were used to pool overall rates, and compare the different techniques. There was no financial funding or conflict of interest.

RESULTS

A total of 29 studies (1,228 patients) were included in this meta-analysis. Total pooled fusion rate was 95.9% (95% CI: 92.7-98.2%) for the anterior/lateral approach. The pooled construct or hardware-related complications was 4.3%, and was similar among anterior/lateral (4.4%) and posterior (5.2%) techniques. The total pooled pseudoarthrosis rate was 4.3% for the lateral approach. The overall pooled rate of motor deficit was 2.7% (95% CI: 1.7-4.0%). Subgroup meta-regression demonstrated that the anterior/lateral approach had the highest rate of motor deficits (3.6% LLIF vs. 0.7% TLIF vs. 0.5% decompression, P=0.004). The overall pooled rate of sensory deficit was 2.4%, highest for the anterior/lateral technique (3.3%) compared to TLIF (0.7%) and decompression (0.5%). The infection rate, dural tears/CSF leak, cardiac and pulmonary events were similar among the techniques, with a pooled value of 2.6%, 3.9%, 1.7%, and 1.4%, respectively. Similarly satisfactory radiological outcomes were obtained amongst the different approaches.

CONCLUSIONS

Minimally invasive spine technologies may be used for the surgical treatment of lumbar degenerative scoliosis with acceptable complication rates, functional and radiological outcome. Future studies, specifically multi-centered longitudinal, examining the adequacy of minimally invasive spine surgery is warranted to compare long-term outcomes with the traditional procedure.

Lateral interbody fusion combined with open posterior surgery for adult spinal deformity

OBJECTIVE Lateral interbody fusion (LIF) with percutaneous screw fixation can treat adult spinal deformity (ASD) in the coronal plane, but sagittal correction is limited. The authors combined LIF with open posterior (OP) surgery using facet osteotomies and a rod-cantilever technique to enhance lumbar lordosis (LL). It is unclear how this hybrid strategy compares to OP surgery alone. The goal of this study was to evaluate the combination of LIF and OP surgery (LIF+OP) for ASD. METHODS All thoracolumbar ASD cases from 2009 to 2014 were reviewed. Patients with < 6 months follow-up, prior fusion, severe sagittal imbalance (sagittal vertical axis > 200 mm or pelvic incidence-LL > 40°), and those undergoing anterior lumbar interbody fusion were excluded. Deformity correction, complications, and outcomes were compared between LIF+OP and OP-only surgery patients. RESULTS LIF+OP (n = 32) and OP-only patients (n = 60) had similar baseline features and posterior fusion levels. On average, 3.8 LIFs were performed. Patients who underwent LIF+OP had less blood loss (1129 vs 1833 ml, p = 0.016) and lower durotomy rates (0% vs 23%, p = 0.002). Patients in the LIF+OP group required less ICU care (0.7 vs 2.8 days, p < 0.001) and inpatient rehabilitation (63% vs 87%, p = 0.015). The incidence of new leg pain, numbness, or weakness was similar between groups (28% vs 22%, p = 0.609). All leg symptoms resolved within 6 months, except in 1 OP-only patient. Follow-up duration was similar (28 vs 25 months, p = 0.462). LIF+OP patients had significantly less pseudarthrosis (6% vs 27%, p = 0.026) and greater improvement in visual analog scale back pain (mean decrease 4.0 vs 1.9, p = 0.046) and Oswestry Disability Index (mean decrease 21 vs 12, p = 0.035) scores. Lumbar coronal correction was greater with LIF+OP surgery (mean [± SD] 22° ± 13° vs 14° ± 13°, p = 0.010). LL restoration was 22° ± 13°, intermediately between OP-only with facet osteotomies (11° ± 7°, p < 0.001) and pedicle subtraction osteotomy (29° ± 10°, p = 0.045). CONCLUSIONS LIF+OP is an effective strategy for ASD of moderate severity. Compared with the authors' OP-only operations, LIF+OP was associated with faster recovery, fewer complications, and greater relief of pain and disability.

An Algorithm to Predict Success of Indirect Decompression Using the Extreme Lateral Lumbar Interbody Fusion Procedure

Purpose: The purpose of this study is to define an algorithm that will predict the success of indirect decompression without the need for direct decompression in patients undergoing lateral lumbar interbody fusions.

Methods and Materials: A prospective cohort study was undertaken for patients undergoing indirect decompression with lateral lumbar interbody fusion. Patients had to meet the following criteria prior to indirect fusion: lack of facet fusion on CT, absence of free disc fragment or compressive facet joint cyst on MRI, absence of frank osteoporosis, lack of congenital and/or severe spinal stenosis on MRI, and significant reduction (greater than 50%) in leg and back pain at rest. We then assessed which patients at follow-up required a second stage open decompression procedure because of continued back and/or leg pain.  

Results: Our series included 28 patients who underwent indirect decompression with extreme lateral lumbar interbody fusion. Of the 28 patients, one patient required a second stage open decompression at follow-up. The most common level operated on was the L4-L5 level. Twelve patients underwent more than a single level fusion. Average preoperative lumbar lordosis was 29 degrees and average postoperative lordosis was 45 degrees. The average patient age was 66.3 years and average follow-up was 1.21 years.  

Conclusions: Our algorithm can be used as an aid to assess which patients may benefit from indirect decompression alone, compared to indirect decompression combined with posterior decompression procedures. 

Lateral lumbar interbody fusion for sagittal balance correction and spinal deformity

We conducted a systematic review to assess the safety and clinical and radiological outcomes of the recently introduced, direct or extreme lateral lumbar interbody fusion (XLIF) approach for degenerative spinal deformity disorders. Open fusion and instrumentation has traditionally been the mainstay treatment. However, in recent years, there has been an increasing emphasis on minimally invasive fusion and instrumentation techniques, with the aim of minimizing surgical trauma and blood loss and reducing hospitalization. From six electronic databases, 21 eligible studies were included for review. The pooled weighted average mean of preoperative visual analogue scale (VAS) pain scores was 6.8, compared to a postoperative VAS score of 2.9 (p<0.0001). The weighted average preoperative and postoperative coronal segmental Cobb angles were 3.6 and 1.1°, respectively. The weighted average preoperative and postoperative coronal regional Cobb angles were 19.1 and 10.0°, respectively. Regional lumbar lordosis also significantly improved from 35.8 to 43.3°. Sagittal alignment was comparable pre- and postoperatively (34 mm versus 35.1mm). The weighted average operative duration was 125.6 minutes, whilst the mean estimated blood loss was 155 mL. The weighted average hospitalization length was 3.6 days. Whilst the available data is limited, minimally invasive XLIF procedures appear to be a promising alternative for the treatment of scoliosis, with improved functional VAS and Oswestry disability index outcomes and restored coronal deformity. Future comparative studies are warranted to assess the long term benefits and risks of XLIF compared to anterior and posterior procedures.

Extreme lateral interbody fusion for unilateral symptomatic vertical foraminal stenosis

PURPOSE

Asymmetric loss of disc height in adult deformity patients may lead to unilateral vertical foraminal stenosis and radiculopathy. The current study aimed to investigate whether restoration of foraminal height on the symptomatic side using extreme lateral interbody fusion (XLIF) would alleviate unilateral radiculopathy.

METHODS

In a retrospective study, patients with single-level unilateral vertical foraminal stenosis and corresponding radicular pain undergoing XLIF were included. Functional data (visual analog scale (VAS) for buttock, leg and back, as well as Oswestry Disability Index (ODI)) and radiographic measurements (bilateral foraminal height, disc height, segmental coronal Cobb angle and regional lumbar lordosis) were collected preoperatively, postoperatively and at the last follow-up.

RESULTS

Twenty-three patients were included, among whom 61 % had degenerative scoliosis. History of previous surgery at the level of index was present in 43 % of patients. Additional instrumentation was performed in 91 %. The foraminal height on the stenotic side was significantly increased postoperatively (p < 0.001), and remained significantly increased at the last follow-up of 11 ± 3.7 months (p < 0.001). Additionally, VAS buttock and leg on the stenotic side, VAS back and ODI were significantly improved postoperatively and at the last follow-up (p ≤ 0.001 for all parameters). The foraminal height on the stenotic side showed correlation with the VAS leg on the stenotic side, both postoperatively and the last follow-up (r = -0.590; p = 0.013, and r = -0.537; p = 0.022, respectively).

CONCLUSIONS

Single-level XLIF is an effective procedure for treatment of symptomatic unilateral foraminal stenosis leading to radiculopathy. In deformity patients with radicular pain caused by nerve compression at a single level, when not associated with other symptoms attributable to general scoliosis, treatment with single-level XLIF can result in short- and mid-term satisfactory outcome.

The role of minimally invasive lateral lumbar interbody fusion in sagittal balance correction and spinal deformity

PURPOSE

The recent proliferation of minimally invasive lateral lumbar interbody fusion (LLIF) techniques has drawn attention to potential for these techniques to control or correct sagittal misalignment in adult spinal deformity. We systemically reviewed published studies related to LLIF use in adult spinal deformity treatment with emphasis on radiographic assessment of sagittal balance.

METHODS

A literature review was conducted to examine studies focusing on sagittal balance restoration in adult degenerative scoliosis with the LLIF approach.

RESULTS

Fourteen publications, 12 retrospective and 2 prospective, reported data regarding lumbar lordosis correction (1,266 levels in 476 patients) but only two measured global sagittal alignment.

CONCLUSION

LLIF appears to be especially effective when the lumbar lordosis and sagittal balance correction goals are less than 10° and 5 cm, respectively. However, the review demonstrated a lack of consistent reporting on sagittal balance restoration with the MIS LLIF techniques.