Early clinical and radiological results of unilateral posterior pedicle instrumentation through a Wiltse approach with lateral lumbar interbody fusion

Minimally Invasive Transforaminal Versus Lateral Lumbar Interbody Fusion for Degenerative Spinal Pathology: Clinical Outcome Comparison in Patients With Predominant Back Pain

STUDY DESIGN

Retrospective review.

OBJECTIVE

To compare perioperative and postoperative clinical outcomes between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and lateral lumbar interbody fusion (LLIF) in patients presenting with predominant back pain.

BACKGROUND

Two popular techniques utilized for lumbar arthrodesis are MIS-TLIF and LLIF. Both techniques have reported high fusion rates and suitable postoperative clinical outcomes. Scarce literature exists, however, comparing these 2 common fusion techniques in a subset population of patients presenting with predominant back pain preoperatively.

METHODS

A retrospective review of lumbar procedures performed between November 2005 and December 2021 was conducted using a prospectively maintained single-surgeon database. Inclusion criteria were set as primary, elective, single, or multilevel MIS-TLIF or LLIF procedures for degenerative spinal pathology in patients with predominant preoperative back pain [visual analog scale (VAS) back pain preoperative score > VAS leg preoperative score]. Patients undergoing a revision procedure, single-level procedure at L5-S1, or surgery indicated for infectious, malignant, or traumatic etiologies were excluded. In addition, patients with VAS leg preoperative scores ≥ to VAS back preoperative scores were excluded. Patient demographics, perioperative characteristics, postoperative complications, and patient-reported outcome measures (PROMs) were collected. PROMs included VAS for back and leg pain, Oswestry Disability Index (ODI), and Short Form-12 (SF-12) Item Survey Mental (MCS) and Physical (PCS) Composite Scores with all values collected at the preoperative, 6-week, 12-week, 6-month, 1-year, and 2-year follow-up time point. Patients were grouped into 2 cohorts, depending on whether a patient underwent a MIS-TLIF or LLIF. Demographic and perioperative characteristics were compared between groups using χ2 and Student t test for categorical and continuous variables, respectively. Mean PROM scores were compared between cohorts at each time point utilizing an unpaired Student t test. Postoperative improvement from preoperative baseline within each cohort was assessed with paired samples t test. Achievement of minimum clinical important difference (MCID) was determined by comparing ΔPROM scores to previously established threshold values. MCID achievement rates were compared between groups with χ2 analysis. Statistical significance was noted as a P value <0.05.

RESULTS

Eligible study cohort included 153 patients, split into 106 patients in the MIS-TLIF cohort and 47 patients in the LLIF cohort. The mean age was 55.9 years, the majority (57.5%) of patients were males, the mean body mass index was 30.8 kg/m2, and the majority of the included cohort were nondiabetic and nonhypertensive. No significant demographic differences were noted between cohorts. The MIS-TLIF cohort had a significantly greater proportion of patients with preoperative spinal pathology of recurrent herniated nucleus pulposus, whereas a significantly greater proportion of patients in the LLIF cohort demonstrated isthmic spondylolisthesis (P < 0.046, all). No significant differences were noted between cohorts for operative duration, estimated blood loss, 1-year rate of arthrodesis, postoperative length of stay, postoperative VAS pain scores on postoperative day 0 or 1, and postoperative narcotic consumption on postoperative day 0 or 1. Patients in the LLIF cohort showed greater rates of postoperative ileus (4.3% vs 0.0%). No other significant differences were noted between cohorts for postoperative complications. Between cohorts, preoperative PROM scores did not significantly differ. The following significant postoperative mean PROM scores were demonstrated: VAS back at 12 weeks and ODI at 12 weeks with both mean scores favoring the LLIF cohort. The MIS-TLIF cohort reported significant improvement from preoperative baseline to the 2-year time point for all PROMs collected at all individual postoperative time points except SF-12 MCS at 6 weeks (P < 0.0, all). LLIF cohort reported significant improvement from preoperative baseline to the 1-year time point for all PROMs collected at all individual postoperative time points except for ODI at 6 weeks, 1 year, and 2 years, SF-12 MCS at 6 weeks and 2 years, and SF-12 PCS at 2 years(P < 0.042, all). The majority of patients in both cohorts achieved overall MCID for VAS back, VAS leg, ODI, and SF-12 PCS. A significantly greater proportion of patients in the LLIF cohort achieved MCID for SF-12 PCS at 12 weeks (94.4% vs 61.1%; P < 0.008).

CONCLUSION

Patients with predominant back pain undergoing MIS-TLIF or LLIF for degenerative spinal pathology demonstrated similar 2-year mean clinical outcomes for physical function, disability, leg pain, and back pain. At the 12-week time point, mean outcome scores for back pain and disability favored the lateral approach with concurrent higher rates of MCID achievement for physical function at that time point.

Short-Term Comparison Between Unilateral Versus Bilateral Percutaneous Pedicle Screw Fixation in Short-Level Lateral Lumbar Interbody Fusion-A Prospective Randomized Study

STUDY DESIGN

Prospective randomized controlled trial.

OBJECTIVES

No prospective studies have directly compared clinical and radiographic outcomes of unilateral vs bilateral instrumented lateral lumbar interbody fusion (LLIF) for lumbar degenerative disease (LDD). We compared the short-term radiographic, clinical outcomes, and some complications of the unilateral percutaneous pedicle screw (PPS) (UPS) vs bilateral PPS (BPS) fixation in short-level spinal fusion with LLIF for LDD.

METHODS

This was a prospective randomized controlled study of 33 patients who underwent UPS or BPS fixation after LLIF for LDD; 18 patients were assigned to the UPS group and 15 patients to the BPS group. Clinical outcomes, complication rates, and fusion rates were assessed.

RESULTS

The two groups were similar in age, sex, preoperative diagnosis, and level of surgery. Blood loss, length of hospital stay, and numeric rating scale score one year after surgery did not differ between groups. The operative time was longer in the BPS than UPS group (120.2 vs 88.8 min, respectively; P = .029). Both groups showed improvement in disc height and dural sac in the immediate postoperative computed tomography and magnetic resonance imaging, which did not differ significantly between groups. The subsidence grade and fusion rate did not differ, but cage subsidence was more severe in the UPS than BPS group.

CONCLUSION

Unilateral and bilateral PPS fixation after LLIF yielded similar short-term clinical and radiological outcomes. However, severe cage subsidence was more common in the UPS group, which suggests that BPS fixation after LLIF may be a better choice over the long term.

Lateral Lumbar Interbody Fusion With rhBMP-2 can Achieve High Fusion Rates in Adult Spine Deformity Surgeries

STUDY DESIGN

An ambispective, observational study of the prospective, institutional adult spine deformity (ASD) database.

OBJECTIVES

The study investigates the clinical and radiographic fusion rates with lateral interbody approach and rhBMP-2 in multiple-level lumbar fusion in the ASD population. Previous studies have reported over 10% pseudoarthrosis rate with multiple segment fusions. Lateral lumbar interbody fusion (LLIF) allows multiple-level, less-invasive access to the anterior lumbar spine. We hypothesized that fusion rates with lateral approach with rhBMP-2 use are superior to the published data on lumbar fusion in ASD patients.

METHODS

The institutional ASD database was searched to identify eligible patients with two or more levels of LLIF (T12-L5), >4 levels of posterior instrumentations and >2 years of follow-up between the years 2010 and 2018. Antero-posterior and lateral 36-inch standing radiographs for each patient and computed tomography scans in select patients were studied to ascertain fusion status and patients were divided into two groups based on fusion status.

RESULTS

The study included 179 patients with a mean age of 65.3 years and 74% female patients. The median number of interbody fusions was performed at 3 (IQR 3-4) levels. The mean follow-up duration was 4.4 years (SD = 1.9). 169 patients (94.5%) had successful arthrodesis, while 10 patients (5.5%) had radiological pseudoarthrosis at one level. Of the 10 patients, 8 (4.4%) were either clinically asymptomatic or had manageable back pain. Two patients (1.1%) required revision surgery for symptomatic pseudoarthrosis.

CONCLUSION

This is the largest known series of ASD patients investigating the fusion rates with multiple-level LLIFs. LLIF along with rhBMP-2 can achieve high fusion success across interbody fusion levels in multi-segmental ASD surgeries.

Hidden blood loss between percutaneous pedicle screw fixation and the mini-open Wiltse approach with pedicle screw fixation for neurologically intact thoracolumbar fractures: a retrospective study

BACKGROUND

The aim of this study was to determine the proportion of hidden blood loss (HBL) in patients treated with minimally invasive surgery, and to compare the HBL between patients treated with percutaneous pedicle screw fixation (PPSF) and the mini-open Wiltse approach with pedicle screw fixation (MWPSF).

METHODS

From January 2017 to January 2019, a total of 119 patients with thoracolumbar fractures were included in the analysis, of which 58 cases received PPSF and 61 cases received MWPSF. The clinical information and demographic results were collected and compared. And the HBL of the patients is calculated by the combination formulas of Nadler, Gross and Sehat.

RESULTS

Compared with the PPSF group, operation time of MWPSF is shorter. The fluoroscopy times are 13.6 ± 3.0 in PPSF group and 5.6 ± 1.6 in MWPSF group (p < 0.001). As shown in Table 3, the intraoperative blood loss in PPSF group is 31.9 ± 9.6 ml, which is significantly less than that in the MWPSF group (44.0 ± 14.9 ml). The HBL (445.7 ± 228.9 ml), and HBL% (91.2 ± 7.7%) of the PPSF group are significantly higher than that in the MWPSF group (P < 0.05). And the total blood loss (TBL) of the PPSF group (477.6 ± 228.8 ml) is also more than that in the MWPSF group (401.0 ± 171.3 ml).

CONCLUSIONS

Our results suggest that in the minimally invasive surgical treatment of thoracolumbar fractures, the perioperative HBL is much higher than visible blood loss (VBL). Although PPSF has less intraoperative blood loss, it has higher TBL and HBL than those of MWPSF. Compared with MWPSF, we should pay more attention to the postoperative anemia status of patients with thoracolumbar fractures undergoing PPSF surgery.

Subsidence of Spinal Fusion Cages: A Systematic Review

BACKGROUND

Although many research studies investigating subsidence of intervertebral fusion cages have been published, to our knowledge, no study has comprehensively compared cage subsidence among all lumbar intervertebral fusion (LIF) techniques. This study aimed to review the literature reporting evidence of cage subsidence linked to LIF. The amount of subsidence was compared and associated with the procedures and corresponding implants used, and the effect of cage subsidence on clinical outcomes was investigated.

METHODS

For this systematic review, the MEDLINE and PubMed databases were used to identify relevant studies. Search terms included lumbar, lumbar vertebrae, lumbar spine, cage, spinal fusion, prosthesis, prosthesis implantation, implantation, implants, interbody, spacer, and subsidence. Studies included in this review were those having more than 10 patients and reporting the amount of subsidence observed using computed tomography or x-ray imaging after surgery and at follow-up visits after a minimum of 6 weeks postsurgery. Data and scale definitions related to subsidence were extracted from articles for comparison of subsidence prevalence between the 5 LIF surgical procedures.

RESULTS

Forty articles were identified for inclusion. The review included data from 390 anterior lumbar intervertebral fusions (ALIFs), 2130 lateral lumbar intervertebral fusions (LLIFs), 560 posterior lumbar intervertebral fusions (PLIFs), 245 oblique lumbar intervertebral fusions (OLIFs), and 1634 transverse lumbar intervertebral fusions (TLIFs) for a total of 4959 patients who underwent LIF surgery. The minimum and maximum percentages of the number of patients having subsidence for each procedure in the included studies were as follows: ALIF stand-alone, 6% and 23.1%; LLIF stand-alone, 8.7% and 39.6%; LLIF with posterior fixation, 3.3% and 20.7%; OLIF with posterior fixation, 4.4% and 36.9%; PLIF with posterior fixation, 7.4% and 31.8%; and TLIF, 0.0% and 51.2%.

CONCLUSIONS

The number of patients experiencing subsidence varied between studies within each fusion procedure. Our findings indicate that all 5 surgical methods are at risk of subsidence. Overall, ALIF without posterior fixation resulted in the lowest reported subsidence occurrence among the 5 surgical approaches. There is conflicting evidence on the association between subsidence and negative clinical outcomes.

CLINICAL RELEVANCE

This review defines and compares subsidence incidence between all LIF procedures and investigates the risk of symptomatic clinical outcomes.

LEVEL OF EVIDENCE: 4

A Comparative Study of a New Retractor‐Assisted WILTSE TLIF, MIS‐TLIF, and Traditional PLIF for Treatment of Single‐Level Lumbar Degenerative Diseases

Objectives

To compare the clinical efficacy of a new retractor‐assisted Wiltse transforaminal lumbar interbody fusion (TLIF), minimally invasive TLIF (MIS‐TLIF), and traditional posterior lumbar interbody fusion (PLIF) in treating single‐level lumbar degenerative diseases.

Methods

A retrospective study was conducted by analyzing the clinical and imaging data of consecutive patients with single‐level lumbar degenerative diseases who underwent the new retractor‐assisted Wiltse TLIF, MIS‐TLIF, or traditional PLIF. This study enrolled 87 concurrent patients between June 2016 and December 2019 (Wiltse TLIF 29 cases; MIS‐TLIF 28 cases; PLIF 30 cases). The three groups were compared for perioperative indicators (including intraoperative blood loss, postoperative drainage volume, operation time, intraoperative fluoroscopy time, bedridden time), creatine kinase (CK), visual analog score (VAS), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) score, intervertebral fusion rate, muscle atrophy, and fatty infiltration (including ratio of multifidus atrophy and ratio of lean‐to‐total cross‐sectional area [CSA]).

Results

Intraoperative blood loss (F = 62.628, p < 0.001), postoperative drainage volume (F = 72.048, p < 0.001), and bedridden time (χ² = 62.289, p < 0.001) were significantly lower in the MIS‐TLIF and Wiltse groups than in the PLIF group. The operative and intraoperative radiation times of the MIS‐TLIF group were significantly longer than those of the Wiltse and PLIF groups. The CK concentration in the Wiltse and MIS‐TLIF groups were significantly lower than those in the PLIF group 1 day (F = 9.331, p < 0.001) and 3 days after surgery (F = 15.967, p < 0.001). The PLIF group's back pain VAS score was higher than those of the Wiltse and MIS‐TLIF groups. The PLIF group had a higher ODI 6 months (F = 3.282, p = 0.042) and 12 months (F = 5.316, p = 0.007) after surgery and a lower JOA score than the Wiltse and MIS‐TLIF groups 6 months (F = 3.234, p = 0.044) and 12 months (F = 3.874, p = 0.025) after surgery. The ratio of multifidus atrophy in the PLIF group (41.70 ± 8.84%) was significantly higher than those of the Wiltse group (24.13 ± 6.82%) and the MIS‐TLIF group (22.35 ± 5.03%). The ratio of lean‐to‐total CSA in the PLIF group was lower than those of the Wiltse and MIS‐TLIF groups after surgery (F = 8.852, p < 0.001). MIS‐TLIF group showed longer operation time (169.11 ± 29.38 min) and intraoperative fluoroscopy time (87.61 ± 3.13 s) than the Wiltse group.

Conclusion

Wiltse TLIF assisted by the new retractor is a more convenient and minimally invasive surgical method than the traditional PLIF and MIS‐TLIF methods, which are linked to a long learning curve and long operation and fluoroscopy time.

Clinical and radiographic analysis of unilateral versus bilateral instrumented one-level lateral lumbar interbody fusion

Lateral lumbar interbody fusion (LLIF) is a widely applied and useful procedure for spinal surgeries. However, posterior fixation has not yet been decided. We compared the radiographic and clinical outcomes of unilateral versus bilateral instrumented one-level LLIF for degenerative lumbar disease. We conducted a prospective cohort study of 100 patients, who underwent unilateral (group U) or bilateral (group B) instrumented one-level LLIF for degenerative lumbar disease. Forty-one patients in group U were undergoing unilateral pedicle screw instrumentation, and 59 patients in group B were undergoing bilateral pedicle screw instrumentation. Clinical characteristic and demographic data before surgery were compared. The intraoperative data, including operative time with changes in positions, intraoperative blood loss, and X-ray exposure time, as well as the perioperative data, including postoperative hospital stay and clinical and radiographic data were compared. As a result, Group U required a significantly shorter operating time than group B. The subsidence grade and fusion rates exhibited no significant differences in the postoperative radiographic evaluation. Group U had better results in clinical assessments than group B. However, group U required more additional surgeries owing to complications.

Differences in radiographic and clinical outcomes of oblique lateral interbody fusion and lateral lumbar interbody fusion for degenerative lumbar disease: a meta-analysis

Background

In the current surgical therapeutic regimen for the degenerative lumbar disease, both oblique lateral interbody fusion (OLIF) and lateral lumbar interbody fusion (LLIF) are gradually accepted. Thus, the objective of this study is to compare the radiographic and clinical outcomes of OLIF and LLIF for the degenerative lumbar disease.

Methods

We conducted an exhaustive literature search of MEDLINE, EMBASE, and the Cochrane Library to find the relevant studies about OLIF and LLIF for the degenerative lumbar disease. Random-effects model was performed to pool the outcomes about disc height (DH), fusion, operative blood loss, operative time, length of hospital stays, complications, visual analog scale (VAS), and Oswestry disability index (ODI).

Results

56 studies were included in this study. The two groups of patients had similar changes in terms of DH, operative blood loss, operative time, hospital stay and the fusion rate (over 90%). The OLIF group showed slightly better VAS and ODI scores improvement. The incidence of perioperative complications of OLIF and LLIF was 26.7 and 27.8% respectively. Higher rates of nerve injury and psoas weakness (21.2%) were reported for LLIF, while higher rates of cage subsidence (5.1%), endplate damage (5.2%) and vascular injury (1.7%) were reported for OLIF.

Conclusions

The two groups are similar in terms of radiographic outcomes, operative blood loss, operative time and the length of hospital stay. The OLIF group shows advantages in VAS and ODI scores improvement. Though the incidence of perioperative complications of OLIF and LLIF is similar, the incidence of main complications is significantly different.