Abstract
Objectives
This study aimed to compare surgical characteristics, complications, and long-term outcomes among open transforaminal lumbar interbody fusion (Open-TLIF), minimally invasive TLIF (MIS-TLIF), and unilateral biportal endoscopic TLIF (UBE-TLIF) for grade I–II degenerative lumbar spondylolisthesis (DLS).
Methods
From January 2018 to June 2020, 279 patients with DLS who underwent Open-TLIF, MIS-TLIF, or UBE-TLIF and completed a 5-year follow-up were enrolled. Based on surgical approach, they were divided into three groups (each n = 93). Baseline characteristics and surgical characteristics were collected during hospitalization, and complications were recorded over the 5-year follow-up. Functional outcomes were assessed using Visual Analog Scale for back pain (VAS-B) and leg pain (VAS-L), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores, while radiographic outcomes were evaluated based on intervertebral disc height (IDH), slip angle, slip percentage, and fusion rate.
Results
The Open-TLIF had the shortest operative time and least fluoroscopy frequency, but the highest blood loss and drainage (P < 0.05). The MIS-TLIF required the longest operation time and most fluoroscopy, while the UBE-TLIF resulted in the smallest incision, least blood loss, shortest hospitalization, and lowest drainage (P < 0.05). Throughout the 5-year follow-up, the MIS-TLIF group showed significantly higher VAS-L and ODI scores, and lower JOA scores at 3 and 5 years compared to the other two groups (P < 0.05). A similar trend was observed in radiographic outcomes such as IDH, slip angle, and slip percentage, with significant differences emerging at 3 years and further increasing at 5 years (P < 0.05). There were no significant differences in total complication rates or fusion rates among the groups (P > 0.05).
Conclusion
While short-term outcomes are similar across techniques, mid- to long-term results favor both Open- and UBE-TLIF. Given its minimally invasive advantages and faster recovery, UBE-TLIF is a preferable alternative for grade I–II DLS.
Keywords: Degenerative lumbar spondylolisthesis, Transforaminal lumbar interbody fusion, Minimally invasive surgery, Unilateral biportal endoscopy, Long-term outcomes
Introduction
Degenerative lumbar spondylolisthesis (DLS), a common leading cause of low back pain, leg pain, or both in middle-aged and elderly populations, is defined as slippage of one vertebra over the subjacent vertebra due to degenerative changes, without an associated disruption in the vertebral arch [1]. It is a common spinal disorder whose incidence increases progressively with age, with reported rates of approximately 4–6% in children, 5–10% in adults, and as high as 25% among elderly individuals in previous literature [2, 3]. Due to the accelerating global population aging trend, its incidence rate continues to rise, particularly in regions where population aging is more pronounced, such as Europe, North America, and China, posing a social burden and a public health concern [4–6].
For the treatment of DLS, clinical management follows a stepwise approach in which surgical intervention is required for patients who are refractory to strict conservative treatment or present with severe neurological deficits. Among various surgical approaches, lumbar interbody fusion is recognized as the gold standard for spinal fusion procedures [7]. With advancements in minimally invasive surgical techniques and instrumentation, endoscopic decompression and interbody fusion have now emerged as a promising alternative. However, conventional endoscopic decompression and interbody fusion techniques are constrained by the narrow visual field and limited instrument maneuverability of single-portal access, which may compromise the adequacy of neural decompression, endplate preparation, and graft placement [8, 9]. To address these shortcomings, unilateral biportal endoscopy (UBE) technique has been developed as an innovative solution. By separating the viewing and working channels, this technique provides an expanded surgical field and greater operational flexibility while preserving minimally invasive advantages [10]. Previous studies have demonstrated that the UBE technique achieves comparable decompression efficacy and fusion rates to those of open surgery and other minimally invasive techniques [11–13]. Nevertheless, current evidence is predominantly limited to short- and mid- term outcomes, leaving its long-term efficacy not fully established and nuanced technical trade-offs inadequately explored, which warrants further validation through well-designed studies.
In this study, we evaluated three clinically established transforaminal lumbar interbody fusion (TLIF) techniques: conventional open TLIF (Open-TLIF), minimally invasive TLIF (MIS-TLIF), and unilateral biportal endoscopic TLIF (UBE-TLIF). By comprehensively comparing these approaches with respect to surgical characteristics, complications, and long-term clinical outcomes, our purpose is to provide evidence-based reference for surgical decision-making.
Patients and methods
Patients
This study included patients with DLS who underwent surgical treatment via Open-TLIF, MIS-TLIF, or UBE-TLIF, derived from a prospective cohort study between January 2018 and June 2020. The inclusion criteria for this study are set as below: (1) patients aged 45–79 years; (2) radiologically confirmed DLS by radiographs, CT, or MRI, with concomitant lumbar instability (≥ 4.5 mm slip distance or ≥ 15° dynamic segmental angle change on flexion–extension radiographs) [14]; (3) failure of ≥ 6-month strict conservative treatment; (4) single-level DLS at L4–L5 or L5–S1 of Meyerding grade I–II; (5) complete study parameter availability during the 5-year follow-up period. Exclusion criteria were as follows: (1) previous history of lumbar surgery; (2) two or more lumbar segmental surgeries; (3) psychiatric and cognitive disorders, malignant tumors, acquired immunodeficiency syndrome, severe motor dysfunction, or other severe comorbidities; (4) non-degenerative spondylolisthesis caused by isthmus defect, traumatic isthmus rupture, and lumbar tuberculosis; (5) osteoporosis (T-score ≤ −2.5 SD) or body mass index (< 18.5 or > 28.0 kg/m2). The sample size was calculated based on the standard deviation of ODI scores reported in a previous study [15]. With α set at 0.05 (two-tailed) and power at 0.80 (1-β), both manual calculations and G*Power verification demonstrated that the required sample size was at least 270 cases, equally distributed with 90 cases per group. We screened eligible patients from the follow-up cohort between January 2018 and June 2020 based on predetermined inclusion and exclusion criteria, identifying 331, 245, and 93 cases for Open-TLIF, MIS-TLIF, or UBE-TLIF, respectively. Using the 93 patients who underwent UBE-TLIF as the reference group, 1:1 matching was performed based on age (± 5 years), sex, body mass index (± 1.0 kg/m2), Meyerding grade, and lumbar bone mineral density T-score (± 0.5). Patient matching was performed manually by independent researchers, with any discrepancies resolved by consensus. This generated three matched groups of 93 patients each for paired comparative analysis.
Perioperative management and surgical techniques
All patients in the three groups underwent surgery under general anesthesia in the prone position, following standardized preoperative evaluations comprising routine blood tests, lumbar radiographic, and surgical eligibility assessment. All operations were conducted by senior surgeons with experience exceeding 300 lumbar endoscopic cases, and the identical surgical technical requirements were employed for segmental localization, neural decompression, endplate preparation, cage implantation, drain placement, and incision closure across all groups. The pedicle screw–rod systems and interbody cages (polyether-ether-ketone or titanium alloy) were provided by Sanyou Medical Co., Ltd. (China) and Weigao Group Co., Ltd. (China), with bone graft materials supplied by CGBio Co., Ltd. (Korea) and DaXiong WeiYe Pharmaceutical Technology Co., Ltd. (China).
The Open-TLIF procedures adhered to the surgical protocol reported by Li et al. [16]. Through a 6-cm midline incision, subperiosteal dissection of paraspinal muscles exposed the facet joints and transverse processes at the target level. After performing facetectomy and foraminotomy, complete discectomy and meticulous endplate preparation were carried out with preservation of bony endplates. An appropriately sized cage packed with autologous bone harvested during laminectomy and facetectomy, and supplemented with allograft when required, was obliquely inserted under fluoroscopic guidance. Finally, bilateral pedicle screw–rod fixation was then implanted through the same midline incision, after which a subfascial drain was placed and the incision was closed in layers.
The MIS-TLIF group underwent surgery using the technique described by Li et al. [17]. A 3-cm paramedian incision was created 2–3 cm lateral to the midline on the symptomatic side. Sequential dilators were inserted through the natural intermuscular plane to establish a surgical corridor, followed by the placement of a tubular retractor system for facet joint exposure. After identifying the facet joint, partial facetectomy was performed to access the disc space. Following facetectomy and foraminotomy using specialized curettes and pituitary rongeurs, the procedure proceeded with canal neural decompression, complete discectomy, and meticulous endplate preparation with careful preservation of the bony endplates. An appropriate cage filled with autologous bone graft or mixed allogeneic bone graft was then implanted. Percutaneous pedicle screw–rod fixation was performed with fluoroscopically assisted needle localization and cannulated screw–rod instrumentation. The procedure concluded with subfascial drain placement and layered incision closure.
In the UBE-TLIF group, the surgical technique was similar to that outlined by Bahir et al. [18]. Two separate 1-cm incisions were created approximately 2 cm lateral to the midline, serving as viewing and working portals, respectively. Using sequential dilation, an endoscope was introduced through the viewing portal while surgical instruments were inserted through the working portal, with continuous saline irrigation maintained at 30–50 mmHg. The facet joint was identified and partially resected with a high-speed endoscopic drill and pituitary rongeurs to access the intervertebral space, enabling subsequent neural decompression. For patients with contralateral nerve compression, the interlaminar decompression was performed by removing the ligamentum flavum and partial laminectomy using a high-speed drill. Following thorough endoscopic neural decompression, discectomy, and endplate preparation, a size-matched cage packed with autologous bone or allograft composite was implanted. Ultimately, the percutaneous fixation, drainage, and incision closure were carried out using the same technique as in the MIS-TLIF group.
Variables and measurements
Baseline data, including age, sex, body mass index, bone mineral density, Meyerding grade, American Society of Anesthesiologists (ASA) grade, comorbidities, and coexisting lumbar disorders, were collected at study enrollment. Perioperative surgical characteristics such as surgical segment, operative time, proportion of autologous bone, interbody fusion device, intraoperative blood loss, and others (full list in Table 2) were documented during hospitalization. Intraoperative blood loss was calculated by the sum of blood loss in the suction bottle and soaked gauzes, which was estimated as follows: each 1 g increase in gauze weight equals 1 mL of blood + (accumulated volume in suction bottle—intraoperative irrigating volume) [19]. Lumbar functional outcomes were assessed using Visual Analog Scale (VAS) for back (VAS-B) and leg (VAS-L) pain, Oswestry Disability Index (ODI), Japanese Orthopaedic Association Scores (JOA), as described in the previous study [20]. In brief, the VAS ranges from 0 (no pain) to 10 (worst pain); the ODI comprises 10 items scored from 0 (no disability) to 5 (maximum disability), with total scores converted to a percentage scale (0–100%); and the JOA ranges from 0 (severe impairment) to 29 (normal function). Radiographic outcomes were evaluated using measurements of intervertebral disc height (IDH), slip angle, slip percentage, and fusion rate. The Dabbs’ method was used to measure IDH on lateral radiographs, calculated as the average of the anterior intervertebral height and posterior intervertebral height [21]. The Taillard’s method and Boxall’s method were applied to evaluate the slip angle and slip percentage, respectively [22]. Specifically, the slip angle was measured as the Cobb angle between the inferior endplate of the superior vertebra and the superior endplate of the inferior vertebra. The slip percentage was defined as the ratio of the slip distance of the superior vertebra to the anteroposterior length of the inferior vertebra, with a postoperative increase of ≥5% considered slip recurrence [23]. Fusion status was assessed using the Bridwell grading criteria, where grades I and II denoted successful fusion, and grades III and IV indicated unsuccessful fusion [24]. These parameters in lumbar functional and radiographic outcomes were assessed preoperatively and postoperatively at 1 month, 6 months, 1 year, 3 years, and 5 years. Complications were collected during hospitalization and follow-up. These measures were independently assessed by two surgeons who were blinded to patient group allocation. Categorical data required unanimous agreement, while continuous data with minor discrepancies (< 10%) were resolved by averaging. For abnormal or disputed data, a third senior surgeon made the final decision.
Table 2.
Comparison of perioperative surgical characteristics
| Parameters | Open-TLIF (n = 93) |
MIS-TLIF (n = 93) |
UBE-TLIF (n = 93) |
χ2/F | P |
|---|---|---|---|---|---|
| Surgical segment | 0.843 | 0.656 | |||
| L4–5 | 54(58.06) | 60(64.52) | 56(60.22) | ||
| L5–S1 | 39(41.94) | 33(35.48) | 37(39.78) | ||
| Operative time (min) | 158.62 ± 28.87 | 180.35 ± 41.48* | 165.77 ± 36.62△ | 8.785 | < 0.001 |
| Proportion of autologous bone | |||||
| <30% | 31(32.26) | 25(26.88) | 23(24.73) | 2.580 | 0.630 |
| 30%–60% | 41(44.09) | 50(53.76) | 47(50.54) | ||
| >60% | 22(23.66) | 18(19.35) | 23(24.73) | ||
| Interbody fusion device | 3.127 | 0.209 | |||
| Titanium alloy | 42(45.16) | 54(58.06) | 47(50.54) | ||
| Polyether-ether-ketone | 51(54.84) | 39(41.94) | 46(49.46) | ||
| Intraoperative blood loss (mL) | 205.27 ± 63.39 | 173.65 ± 51.78* | 132.81 ± 42.74#△ | 43.184 | < 0.001 |
| Fluoroscopy use (times) | 4.41 ± 1.50 | 6.17 ± 2.35* | 5.34 ± 1.80#△ | 19.640 | < 0.001 |
| Incision length (cm) | 6.38 ± 0.97 | 6.15 ± 1.22 | 5.94 ± 1.03# | 3.872 | 0.022 |
| Postoperative drainage (mL) | 152.70 ± 40.26 | 23.74 ± 31.89* | 97.65 ± 28.72#△ | 61.100 | < 0.001 |
| Postoperative ambulation time (d) | 3.20 ± 1.27 | 3.09 ± 1.15 | 2.88 ± 0.95 | 1.922 | 0.148 |
| Hospitalization duration (d) | 10.23 ± 3.12 | 9.62 ± 2.53 | 8.91 ± 2.76# | 5.126 | 0.007 |
Open-TLIF open transforaminal lumbar interbody fusion, MIS-TLIF minimally invasive transforaminal lumbar interbody fusion, UBE-TLIF unilateral biportal endoscopic transforaminal lumbar interbody fusion
*MIS-TLIF group vs. Open-TLIF group, P < 0.05; #UBE-TLIF group vs. Open-TLIF group, P < 0.05; △UBE-TLIF group vs. MIS-TLIF group, P < 0.05
Statistical analysis
Statistical analysis was performed using SPSS version 26.0. The normality assumption for continuous data was assessed using the Shapiro–Wilk test. Data violating this assumption were analyzed by the Kruskal–Wallis H test. Normally distributed data were presented as mean ± standard deviation (‾x ± s) and compared among the three groups using analysis of variance, followed by Student–Newman–Keuls test for pairwise comparisons. Comparison of measurement data across different time points was conducted using repeated-measures analysis of variance. When a significant time-by-group interaction effect was observed, simple effect analysis was performed for further comparisons. If a significant main effect of time or group was found, the Bonferroni test was used for pairwise comparisons. Categorical data were presented as frequencies and percentages and were evaluated using Pearson’s Chi-square (χ2) tests or Fisher’s exact test, as appropriate. A two-tailed P-value < 0.05 was considered statistically significant.
Results
Comparison of baseline data
After baseline matching, no statistically significant differences were observed among the three groups regarding age, sex, body mass index, bone mineral density, or Meyerding grade (P > 0.05). Additionally, no statistically significant differences were found in ASA grade, comorbidities, and coexisting lumbar disorders (P > 0.05). Collectively, these results demonstrated well-balanced baseline data across all groups. Details are shown in Table 1.
Table 1.
Comparison of baseline data
| Parameters | Open-TLIF (n = 93) |
MIS-TLIF (n = 93) |
UBE-TLIF (n = 93) |
F/χ2/H | P |
|---|---|---|---|---|---|
| Age (years) | 61.45 ± 7.23 | 60.76 ± 6.84 | 61.18 ± 6.73 | 0.234 | 0.792 |
| Sex | |||||
| Male | 32(34.41) | 32(34.41) | 32(34.41) | – | 1.000 |
| Female | 61(65.59) | 61(65.59) | 61(65.59) | ||
| Body mass index (kg/m2) | 24.23 ± 1.85 | 23.89 ± 2.10 | 24.08 ± 1.90 | 0.708 | 0.494 |
| Bone mineral density (T-score) | − 1.21 ± 0.38 | − 1.23 ± 0.45 | − 1.17 ± 0.41 | 0.506 | 0.604 |
| Meyerding grade | |||||
| Ⅰ | 58(62.37) | 58(62.37) | 58(62.37) | – | 1.000 |
| Ⅱ | 35(37.63) | 35(37.63) | 35(37.63) | ||
| ASA grade | |||||
| Ⅰ | 53(56.99) | 61(65.59) | 56(60.22) | 1.476 | 0.458 |
| Ⅱ | 40(43.01) | 32(34.41) | 37(39.78) | ||
| Comorbidities | |||||
| Hypertension | 36(38.71) | 39(41.94) | 34(36.56) | 0.572 | 0.751 |
| Diabetes | 21(22.58) | 20(21.51) | 19(20.00) | 0.188 | 0.910 |
| Coronary heart disease | 18(19.35) | 22(23.66) | 20(21.51) | 0.510 | 0.775 |
| Other chronic diseases | 15(16.13) | 19(20.43) | 14(15.05) | 1.057 | 0.590 |
| Coexisting lumbar disorders | |||||
| Lumbar disc herniation | 38(40.86) | 31(33.33) | 34(35.56) | 1.139 | 0.566 |
| Spinal stenosis | 25(26.88) | 20(21.51) | 23(24.73) | 0.739 | 0.691 |
| Other degenerative changes | 31(33.33) | 40(43.01) | 34(36.56) | 1.924 | 0.382 |
Open-TLIF open transforaminal lumbar interbody fusion, MIS-TLIF minimally invasive transforaminal lumbar interbody fusion, UBE-TLIF unilateral biportal endoscopic transforaminal lumbar interbody fusion
Comparison of perioperative surgical characteristics
No significant differences were observed among the three groups in surgical segment, proportion of autologous bone, interbody fusion device, and postoperative ambulation time (P > 0.05). However, significant differences were noted in the following parameters: the Open-TLIF group had the shortest operative time and lowest fluoroscopy frequency but the highest intraoperative blood loss and postoperative drainage compared to the MIS-TLIF and UBE-TLIF groups; the MIS-TLIF group showed the longest operative time and most frequent fluoroscopy relative to the other two groups; while the UBE-TLIF group exhibited the shortest incision length, along with the lowest intraoperative blood loss and postoperative drainage, hospitalization duration among the three groups. All above-mentioned differences were statistically significant (P < 0.05). Details are shown in Table 2.
Comparison of functional outcomes
Repeated-measures analysis of variance revealed significant time-by-group interactions for VAS-B and ODI scores (P < 0.05), whereas no significant interactions were observed for VAS-L and JOA scores (P > 0.05). Simple effects analyses revealed that the Open-TLIF group exhibited significantly higher VAS-B scores than both the MIS-TLIF and UBE-TLIF groups at 1 month postoperatively, with the MIS-TLIF group also demonstrating notably higher scores than the UBE-TLIF group. Furthermore, the MIS-TLIF group showed significantly higher ODI scores compared to the other two groups at 3- and 5-year intervals. Further intergroup comparisons revealed that the MIS-TLIF group exhibited significantly higher VAS-L scores than both the Open-TLIF and UBE-TLIF groups at 3- and 5-year intervals. Additionally, the MIS-TLIF group demonstrated significantly lower JOA scores compared to the Open-TLIF group at 1 year and to both comparison groups at 3 and 5 years. All aforementioned reported differences were statistically significant (P < 0.05). Details are shown in Table 3 and Fig. 1.
Table 3.
Comparison of functional outcomes
| Parameters | n | Preop | Postop | Time effect | Group effect | Time-by-group | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 month | 6 months | 1 year | 3 years | 5 years | ||||||
| VAS-B (points) | ||||||||||
| Open-TLIF | 93 | 6.62 ± 1.64 | 3.04 ± 1.23 | 2.15 ± 1.10 | 1.57 ± 0.81 | 1.38 ± 0.64 | 1.51 ± 0.77 | |||
| MIS-TLIF | 93 | 6.37 ± 1.46 | 2.71 ± 1.08* | 2.09 ± 0.86 | 1.70 ± 0.92 | 1.54 ± 0.77 | 1.67 ± 0.82 | |||
| UBE-TLIF | 93 | 6.55 ± 1.52 | 2.32 ± 0.95#△ | 1.87 ± 0.91 | 1.48 ± 0.73 | 1.41 ± 0.68 | 1.45 ± 0.70 | |||
| F | 1014.415 | 6.379 | 2.380 | |||||||
| P | < 0.001 | 0.002 | 0.019 | |||||||
| VAS-L (points) | ||||||||||
| Open-TLIF | 93 | 7.03 ± 1.73 | 2.67 ± 1.25 | 1.86 ± 0.92 | 1.58 ± 0.71 | 1.16 ± 0.60 | 1.34 ± 0.71 | |||
| MIS-TLIF | 93 | 6.65 ± 1.58 | 2.90 ± 1.34 | 2.12 ± 1.03 | 1.80 ± 0.87 | 1.48 ± 0.77* | 1.69 ± 0.81* | |||
| UBE-TLIF | 93 | 6.84 ± 1.69 | 2.78 ± 1.28 | 1.92 ± 0.86 | 1.60 ± 0.77 | 1.20 ± 0.65△ | 1.25 ± 0.62△ | |||
| F | 1078.637 | 4.698 | 1.784 | |||||||
| P | < 0.001 | 0.010 | 0.086 | |||||||
| ODI (%) | ||||||||||
| Open-TLIF | 93 | 49.42 ± 6.95 | 30.27 ± 6.17 | 18.87 ± 4.65 | 13.19 ± 5.06 | 8.71 ± 3.89 | 10.24 ± 4.28 | |||
| MIS-TLIF | 93 | 47.96 ± 7.63 | 28.86 ± 5.34 | 20.48 ± 6.02 | 14.20 ± 4.48 | 11.54 ± 5.10* | 13.53 ± 5.36* | |||
| UBE-TLIF | 93 | 50.03 ± 8.18 | 29.36 ± 6.49 | 19.35 ± 5.21 | 12.97 ± 5.17 | 9.21 ± 4.05△ | 11.64 ± 3.87△ | |||
| F | 2005.983 | 5.043 | 3.706 | |||||||
| P | < 0.001 | 0.007 | < 0.001 | |||||||
| JOA (points) | ||||||||||
| Open-TLIF | 93 | 12.68 ± 3.29 | 16.91 ± 4.06 | 23.35 ± 2.95 | 24.15 ± 2.23 | 26.06 ± 1.79 | 24.57 ± 2.41 | |||
| MIS-TLIF | 93 | 13.12 ± 4.23 | 16.30 ± 3.64 | 22.43 ± 4.11 | 23.27 ± 3.15* | 24.86 ± 2.32* | 23.35 ± 2.86* | |||
| UBE-TLIF | 93 | 12.37 ± 3.56 | 17.22 ± 4.18 | 23.17 ± 3.39 | 23.85 ± 2.50 | 25.63 ± 1.95△ | 24.89 ± 2.04△ | |||
| F | 735.119 | 8.616 | 1.680 | |||||||
| P | < 0.001 | < 0.001 | 0.093 | |||||||
Open-TLIF open transforaminal lumbar interbody fusion, MIS-TLIF minimally invasive transforaminal lumbar interbody fusion, UBE-TLIF unilateral biportal endoscopic transforaminal lumbar interbody fusion
*MIS-TLIF group vs. Open-TLIF group, P < 0.05; #UBE-TLIF group vs. Open-TLIF group, P < 0.05; △UBE-TLIF group vs. MIS-TLIF group, P < 0.05
Fig. 1.
A-D This figure illustrates longitudinal changes and intergroup comparisons of functional outcomes across the three groups during a 5-year follow-up period: A Visual Analog Scale for back pain (VAS-B). B Visual Analog Scale for leg pain (VAS-L). C Oswestry Disability Index (ODI). D Japanese Orthopaedic Association score (JOA). *MIS-TLIF group vs. Open-TLIF group, P < 0.05; #UBE-TLIF group vs. Open-TLIF group, P < 0.05; △UBE-TLIF group vs. MIS-TLIF group, P < 0.05
Comparison of radiographic outcomes
Repeated-measures analysis of variance showed nonsignificant time-by-group interactions for both IDH and slip percentage (P > 0.05), but a significant interaction for slip angle (P < 0.05). Subsequent intergroup comparisons revealed significantly lower IDH in the MIS-TLIF group than in the Open-TLIF group at 3 years postoperatively, and significantly lower than both the Open-TLIF and UBE-TLIF groups at 5 years postoperatively. For slip percentage, the MIS-TLIF group demonstrated significantly higher values than the other two groups at 3- and 5-year intervals, with the Open-TLIF group exhibiting significantly higher values relative to the UBE-TLIF group. Simple effects analyses indicated that the MIS-TLIF group had significantly greater slip angle than the other two groups at 3 and 5 years. All differences mentioned above were statistically significant (P < 0.05). Additionally, no significant differences were found in fusion rates across the three groups during the 5-year follow-up (P > 0.05). Details are shown in Table 4 and Fig. 2.
Table 4.
Comparison of radiographic outcomes
| Parameters | n | Preop | Postop | Time effect | Group effect | Time-by-group | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 month | 6 months | 1 year | 3 years | 5 years | ||||||
| IDH (mm) | ||||||||||
| Open-TLIF | 93 | 8.03 ± 2.14 | 12.12 ± 1.03 | 12.01 ± 1.40 | 11.70 ± 1.48 | 11.51 ± 1.29 | 10.92 ± 1.51 | |||
| MIS-TLIF | 93 | 7.86 ± 2.05 | 11.91 ± 1.30 | 11.64 ± 1.57 | 11.33 ± 1.71 | 10.86 ± 1.54* | 9.95 ± 1.68* | |||
| UBE-TLIF | 93 | 7.57 ± 2.30 | 12.02 ± 1.18 | 11.72 ± 1.31 | 11.51 ± 1.60 | 11.16 ± 1.42 | 10.64 ± 1.75△ | |||
| F | 265.079 | 10.833 | 1.284 | |||||||
| P | < 0.001 | < 0.001 | 0.242 | |||||||
| Slip angle (°) | ||||||||||
| Open-TLIF | 93 | 13.02 ± 5.04 | 4.89 ± 1.43 | 5.57 ± 1.68 | 4.98 ± 1.83 | 5.63 ± 2.57 | 6.31 ± 2.26 | |||
| MIS-TLIF | 93 | 12.43 ± 4.47 | 5.24 ± 1.82 | 6.03 ± 2.06 | 5.72 ± 1.91 | 6.84 ± 2.70* | 7.56 ± 2.83* | |||
| UBE-TLIF | 93 | 11.96 ± 3.90 | 5.05 ± 1.53 | 5.86 ± 1.92 | 5.23 ± 2.16 | 6.03 ± 2.04△ | 6.08 ± 2.51△ | |||
| F | 303.698 | 8.916 | 2.208 | |||||||
| P | < 0.001 | < 0.001 | 0.038 | |||||||
| Slip percentage (%) | ||||||||||
| Open-TLIF | 93 | 24.72 ± 7.63 | 4.89 ± 1.97 | 5.11 ± 2.40 | 5.74 ± 2.51 | 6.28 ± 2.84 | 6.99 ± 2.36 | |||
| MIS-TLIF | 93 | 23.65 ± 8.28 | 5.30 ± 2.46 | 5.67 ± 2.81 | 6.43 ± 2.69 | 7.41 ± 3.15* | 7.89 ± 3.02△ | |||
| UBE-TLIF | 93 | 24.29 ± 8.51 | 5.26 ± 2.17 | 5.30 ± 2.59 | 5.83 ± 2.34 | 5.95 ± 2.66* | 6.01 ± 2.58#△ | |||
| F | 939.258 | 3.337 | 1.601 | |||||||
| P | < 0.001 | 0.037 | 0.171 | |||||||
| Fusion rate (%) | ||||||||||
| Open− TLIF | 93 | – | – | 40(43.01) | 76(81.72) | 90(96.77) | 93(100.00) | |||
| MIS-TLIF | 93 | – | – | 34(36.56) | 69(74.19) | 88(94.62) | 91(97.85) | |||
| UBE-TLIF | 93 | – | – | 37(39.78) | 74(79.57) | 91(97.85) | 92(98.92) | |||
| χ2 | 0.808 | 1.656 | –☆ | –☆ | ||||||
| P | 0.668 | 0.437 | 0.616 | 0.368 | ||||||
Open-TLIF open transforaminal lumbar interbody fusion, MIS-TLIF minimally invasive transforaminal lumbar interbody fusion, UBE-TLIF unilateral biportal endoscopic transforaminal lumbar interbody fusion
*MIS-TLIF group vs. Open-TLIF group, P < 0.05; #UBE-TLIF group vs. Open-TLIF group, P < 0.05; △UBE-TLIF group vs. MIS-TLIF group, P < 0.05; ☆Fisher’s exact test
Fig. 2.
A-D This figure illustrates longitudinal changes and intergroup comparisons of radiographic outcomes among the three groups during a 5-year follow-up period: A intervertebral disc height (IDH), B slip angle, C slip percentage, D fusion rate. *MIS-TLIF group vs. Open-TLIF group, P < 0.05; #UBE-TLIF group vs. Open-TLIF group, P < 0.05; △UBE-TLIF group vs. MIS-TLIF group, P < 0.05
Comparison of complications
The total complication rates in the Open-TLIF, MIS-TLIF, and UBE-TLIF groups were 24.73% (24/93), 30.11% (28/93), and 21.53% (20/93), respectively, with no statistically significant differences among the three groups (P > 0.05). The most common perioperative complications included dural tear, nerve root injury, and surgical site infection. During long-term follow-up, the predominant late-onset complications were cage subsidence, adjacent segment degeneration, and cage migration. Details are shown in Table 5.
Table 5.
Comparison of complications
| Parameters | Open-TLIF (n = 93) |
MIS-TLIF (n = 93) |
UBE-TLIF (n = 93) |
χ2 | P |
|---|---|---|---|---|---|
| Perioperative complications | 12(12.90) | 17(18.28) | 13(13.98) | ||
| Dural tear | 2(2.15) | 5(5.38) | 4(4.30) | ||
| Nerve root injury | 1(1.08) | 4(4.30) | 2(2.15) | ||
| Endplate damage | 0(0.00) | 1(1.08) | 1(1.08) | ||
| Incomplete decompression | 0(0.00) | 2(2.15) | 1(1.08) | ||
| Cerebrospinal fluid leakage | 2(2.15) | 1(1.08) | 2(2.15) | ||
| Epidural hematoma | 1(1.08) | 1(1.08) | 0(0.00) | ||
| Surgical site infection | 4(4.30) | 1(1.08) | 2(2.15) | ||
| Transient palsy | 2(2.15) | 2(2.15) | 1(1.08) | ||
| Late-onset complications | 11(11.83) | 11(11.83) | 7(7.53) | ||
| Fascial hernia | 1(1.08) | 0(0.00) | 0(0.00) | ||
| Cage subsidence | 2(2.15) | 4(4.30) | 2(2.15) | ||
| Cage migration | 1(1.08) | 2(2.15) | 1(1.08) | ||
| Screw loosening/breakage | 2(2.15) | 1(1.08) | 1(1.08) | ||
| Pseudarthrosis | 0(0.00) | 1(1.08) | 0(0.00) | ||
| Adjacent segment degeneration | 4(4.30) | 3(3.23) | 2(2.15) | ||
| Slip recurrence | 1(1.08) | 0(0.00) | 1(1.08) | ||
| Total complication rates | 23(24.73) | 28(30.11) | 20(21.51) | 1.851 | 0.396 |
Open-TLIF open transforaminal lumbar interbody fusion, MIS-TLIF minimally invasive transforaminal lumbar interbody fusion, UBE-TLIF unilateral biportal endoscopic transforaminal lumbar interbody fusion
Discussion
Driven by decades of evolving minimally invasive concepts and breakthroughs in endoscopic technology, lumbar surgery has evolved through three distinct stages: open surgery, minimally invasive surgery, and endoscopic surgery (including endoscopic-assisted, full-endoscopic, and microscopic techniques), with increasing popularity in clinical practice [25–27]. This evolution not only represents reduced surgical trauma and blood loss but also reflects a paradigm shift toward tissue preservation in surgical approaches. Whereas traditional open surgery compromises the integrity of paraspinal muscles, laminae, and facet joints to achieve adequate exposure, minimally invasive techniques maximize preservation of normal bone and soft tissue while ensuring precise therapeutic outcomes. This transformation has significantly decreased iatrogenic surgical injury, demonstrating the progressive refinement of damage control principles in spine surgery over recent years. The clinical outcomes and application value of minimally invasive spinal technologies, however, necessitate validation through long-term follow-up, particularly since whether endoscopic techniques can maintain their minimally invasive advantages while achieving clinical outcomes comparable to open surgery remains controversial [28]. Addressing these issues is critical for establishing an evidence-based surgical selection framework. Utilizing 5-year follow-up data, this study compares TLIF techniques across different surgical approaches in terms of operative characteristics, functional recovery, radiographic parameters, and complication profiles. A primary focus lies in evaluating UBE-TLIF's potential to resolve the minimally invasive versus efficacy dilemma, thereby informing clinical decision-making.
For comparison of perioperative surgical characteristics, our results revealed that while Open-TLIF had the shortest operative time and lowest fluoroscopy frequency, it exhibited the highest intraoperative blood loss and postoperative drainage; MIS-TLIF required the longest operative time and most frequent fluoroscopy but demonstrated intermediate outcomes for blood loss and drainage; whereas UBE-TLIF achieved the shortest hospitalization duration, incision length with minimal blood loss and drainage. Regarding operative time, while some perspectives suggest prolonged durations with UBE, we contend this disparity relates primarily to surgical proficiency. As established in the literature, UBE entails a steep learning curve; only after overcoming this proficiency barrier can surgeons shorten operative times [29]. The minimally invasive groups (MIS-TLIF and UBE-TLIF) required more frequent fluoroscopy use than the Open-TLIF group, which may be due to the repeated verification of guidewire and pedicle screw positions. Previous studies indicate that minimally invasive techniques have a significant advantage in incision length. However, this study observed only marginal superiority for UBE-TLIF, likely resulting from additional incisions required during percutaneous pedicle screw–rod fixation installation. The greater blood loss in Open-TLIF was associated with extensive soft tissue dissection, while the less blood loss of UBE-TLIF derived from elevated continuous pressure irrigation and efficient hemostasis under clear visualization [30]. Also, extensive tissue dissection also explains the significantly higher postoperative drainage in the Open-TLIF group compared to the minimally invasive techniques. Moreover, reduced blood loss and surgical trauma facilitated postoperative recovery, resulting in the shortest hospital stay for UBE. Collectively, the UBE demonstrates superior perioperative outcomes in minimizing surgical trauma, reducing blood loss, and expediting recovery. These findings align with published evidence [31].
Throughout the 5-year follow-up period, lumbar functional outcomes were evaluated using four established metrics: VAS-B, VAS-L, ODI, and JOA scores. All surgical groups demonstrated significant postoperative improvement across these parameters, with broadly similar recovery trajectories in the recent period after surgery. However, the Open-TLIF group exhibited higher VAS-B scores than both minimally invasive groups at the 1-month postoperative assessment. This discrepancy demonstrated transient characteristics, resolving rapidly thereafter, which likely stems from paraspinal muscle injury inherent to open surgical approaches [32]. Beginning at 1 year postoperatively, significant divergences developed among the three groups in JOA scores. By postoperative years 3 and 5, the Open-TLIF and UBE-TLIF groups demonstrated superior outcomes in VAS-L, ODI, and JOA scores compared to the MIS-TLIF group. Regarding radiographic outcomes, a similar trend occurred in parameters including IDH, slip angle, and slip percentage, where significant differences emerged by 3 years and further increased at 5 years postoperatively. No significant intergroup differences were found at most observation time points within 3 years after surgery, likely attributable to the consistent use of interbody fusion with rod-screw fixation systems. However, progressive intergroup differences were observed during postoperative years 3–5 following internal fixation removal in selected fused patients, leading to increasingly significant disparities over time. Our findings indicate that Open-TLIF yields superior long-term functional outcomes and radiographic parameters compared to MIS-TLIF, while UBE-TLIF achieves results comparable to Open-TLIF. In agreement with our findings, the superior functional and radiographic outcomes are corroborated by other studies [33, 34]. As reported by Gatam et al. [35], UBE technique yields favorable mid- to long-term outcomes and, with further refinement, may become the next gold standard for treating degenerative lumbar disorders. In our opinion, the efficacy of UBE primarily originates in three critical factors: its magnified high-definition visualization, specialized instrumentation enabling precise endplate preparation, and thorough interlaminar decompression. These advantages collectively facilitate an optimal balance between surgical trauma and clinical efficacy, achieving mid- to long-term clinical outcomes comparable to open surgery. Nevertheless, the follow-up duration of this study was limited to 5 years, necessitating extended comparative analysis for more long-term validation.
In this study, the primary perioperative complications included dural tear, nerve root injury, and surgical site infection, while the predominant late-onset complications during follow-up mainly comprised cage subsidence, adjacent segment degeneration, and cage migration, which largely corresponded to the distribution reported in analogous studies [36, 37]. Differently, this study observed a higher incidence of adjacent segment degeneration, which may be related to our extended follow-up period. Overall, there was no significant difference in the overall incidence of complications among the three groups, but we found that our total rates were higher than the 19% rate of single-level lumbar fusion reported by others [38]. This discrepancy may be attributed to two primary factors: most studies documented only perioperative and short-term complications, whereas our study captured complications spanning a five-year period, accounting for the higher complication rates observed; additionally, our detailed documentation of complication categories contributed to a relatively higher overall incidence. Perioperative complications such as dural tears, nerve root injuries, and surgical site infections are partially associated with surgical proficiency, where refined technical skills reduce their incidence. However, cage subsidence and migration correlate not only with surgical technique, but also with rehabilitation regimens, spinal loading dynamics, and lumbar bone mineral density [39, 40]. This necessitates extending clinical focus beyond operative techniques to implement structured postoperative education during follow-up, thereby mitigating such complications. Currently, adjacent segment degeneration still remains a major long-term complication of lumbar fusion, primarily resulting from mechanical immobilization of the operated segment and compensatory overload in adjacent segments. This concern may be effectively addressed through future maturation of motion-preserving technologies such as lumbar disc replacement [41].
This study has several limitations. First, as this study prioritized detecting mid- to long-term outcome differences, it inadvertently omitted the assessment of several perioperative parameters, including intraoperative hidden blood loss, muscle injury biomarkers (e.g., CK, CK-MB, LDH), and postoperative MRI-based paraspinal muscle evaluation across surgical approaches. As reported by Güneş et al. [42], lumbar muscle mass and balance are closely associated with patient pain, disability, and risk of falls. Thus, this omission identifies a clear need for future research in this area. Second, we utilized a matched-pair design for comparison of long-term outcomes, with matching variables (age, sex, body mass index, and Meyerding grade) selected based on established evidence identifying these factors as significant predictors of clinical outcomes in lumbar fusion patients [43–45]. Despite adjusting for confounders and improving comparability, this method leaves variables such as genetic susceptibility, rehabilitation, and lumbar loading unaddressed, which must be considered as potential biases. Third, the eligibility criteria restricted enrollment to patients with single-level, grade I–II DLS, limiting the generalizability of our findings to higher-grade or multilevel cases. While endoscopic surgery has been explored for such complex scenarios, the existing evidence is preliminary and insufficient, necessitating validation through more robust studies. Finally, this study failed to apply a randomized controlled design because some patients require changes to the surgical plan after randomization, and a large number of patients are lost to follow-up after 3 years. Consequently, patients were selected from a prospective follow-up cohort, limiting operational replication of RCT-level methodological rigor. Considering these limitations, conducting a rigorously designed, large-scale, multicenter RCT remains imperative in the future.
Conclusion
The short-term outcomes of Open-TLIF, MIS-TLIF, and UBE-TLIF are similar, while the mid- to long-term results reveal superior efficacy of both Open-TLIF and UBE-TLIF over MIS-TLIF, with Open-TLIF and UBE-TLIF achieving comparable outcomes. Considering the advantages of UBE-TLIF, such as minimal invasiveness, reduced blood loss, and faster recovery, it represents a preferable surgical alternative for patients with grade I–II DLS. However, due to its single-center design and limited sample size, future large-sample, higher-level RCTs are warranted to confirm our findings.
Acknowledgements
We sincerely appreciate all colleagues for their support.
Author contributions
JL conceived the study and drafted the manuscript. JL, LS, and CB completed data collection and analysis. LS and ZG performed the manuscript review and editing. ZG was responsible for the supervision of the study.
Funding
No support from any funding in this study.
Data availability
The data in this study are available on request from the corresponding author.
Declarations
Ethical approval and consent to participate
This study was approved by the Medical Ethics Committee of Linping Campus, Second Affiliated Hospital of Zhejiang University (Approval No: LP23ld058). The personal identifiers of patients were removed and the data were analyzed anonymously, and the informed consent was obtained from all patients.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Saremi A, Goyal KK, Benzel EC, et al. Evolution of lumbar degenerative spondylolisthesis with key radiographic features. Spine J. 2024;24:989–1000. [DOI] [PubMed] [Google Scholar]
- 2.Daher M, Rezk A, Baroudi M, et al. Lumbar spondylolisthesis grading: current standards and important factors to consider for management. World Neurosurg. 2024;190:311–7. [DOI] [PubMed] [Google Scholar]
- 3.Ball JR, Gallo MC, Kebaish K, et al. National trends in lumbar degenerative spondylolisthesis with stenosis treated with fusion versus decompression. Neurospine. 2024;21(4):1068–77. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Heck VJ, Klug K, Prasse T, et al. Projections from surgical use models in Germany suggest a rising number of spinal fusions in patients 75 years and older will challenge healthcare systems worldwide. Clin Orthop Relat Res. 2023;481(8):1610–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Wang YXJ, Káplár Z, Deng M, et al. Lumbar degenerative spondylolisthesis epidemiology: a systematic review with a focus on gender-specific and age-specific prevalence. J Orthop Translat. 2016;11:39–52. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Alonso-García M, Sarría-Santamera A. The economic and social burden of low back pain in Spain: a national assessment of the economic and social impact of low back pain in Spain. Spine (Phila Pa 1976). 2020;45(16):1026–32. [DOI] [PubMed] [Google Scholar]
- 7.Park HW, Han MS, Jung JH, et al. Posterior lumbar element enforcement by decompression alone with interspinous fixation without interbody fusion for the surgical management of lumbar spondylolisthesis. J Korean Neurosurg Soc. 2025;68(2):150–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Burkett D, Brooks N. Advances and challenges of endoscopic spine surgery. J Clin Med. 2024;13(5):1439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Pao JL. Biportal endoscopic transforaminal lumbar interbody fusion using double cages: surgical techniques and treatment outcomes. Neurospine. 2023;20(1):80–91. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Park DK, Weng C, Zakko P, et al. Unilateral biportal endoscopy for lumbar spinal stenosis and lumbar disc herniation. JBJS Essent Surg Tech. 2023;13(2):e22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Lee DH, Lee DG, Park CK, et al. Saving stabilizing structure treatment with bilateral-contralateral decompression for spinal stenosis in degenerative spondylolisthesis using unilateral biportal endoscopy. Neurospine. 2023;20(3):931–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Yang H, Cheng F, Hai Y, et al. Unilateral biportal endoscopic lumbar interbody fusion enhanced the recovery of patients with the lumbar degenerative disease compared with the conventional posterior procedures: a systematic review and meta-analysis. Front Neurol. 2023;13:1089981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Hu Q, Xiao K, Nan JN, et al. Comparative evaluation of efficacy and complications between biportal endoscopic lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative diseases: a systematic review and meta-analysis. J Pain Res. 2025;18:2215–31. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Chou SH, Lin SY, Shen PC, et al. Pain control affects the radiographic diagnosis of segmental instability in patients with degenerative lumbar spondylolisthesis. J Clin Med. 2021;10(17):3984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Elmekaty M, Kotani Y, Mehy EE, et al. Clinical and radiological comparison between three different minimally invasive surgical fusion techniques for single-level lumbar isthmic and degenerative spondylolisthesis: minimally invasive surgical posterolateral fusion versus minimally invasive surgical transforaminal lumbar interbody fusion versus midline lumbar fusion. Asian Spine J. 2018;12(5):870–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Li HJ, Ge DW, Zhang S, et al. Comparative study between mini-open TLIF via Wiltse’s approach and conventional open TLIF in lumbar degenerative diseases. Eur Rev Med Pharmacol Sci. 2018;22(1S):53–62. [DOI] [PubMed] [Google Scholar]
- 17.Li S, Zhou Z, Meng F, et al. Comparison of mMO-TLIF via midline incision versus MIS-TLIF via Wiltse approach in lumbar degenerative disease. Indian J Orthop. 2024;58(9):1278–87. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Bahir AW, Daxing W, Jiayu X, et al. Comparative efficacy and fusion outcomes of unilateral bi-portal endoscopic transforaminal lumbar interbody fusion versus minimally invasive transforaminal lumbar interbody fusion in treating single-segment degenerative lumbar spondylolisthesis with lumbar spinal stenosis: a two-year retrospective study. J Orthop Surg Res. 2024;19(1):835. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Huang X, Wang W, Chen G, et al. Comparison of surgical invasiveness, hidden blood loss, and clinical outcome between unilateral biportal endoscopic and minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative disease: a retrospective cohort study. BMC Musculoskelet Disord. 2023;24(1):274. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Chen G, Li LB, Shangguan Z, et al. Clinical effect of minimally invasive microendoscopic-assisted transforaminal lumbar interbody fusion for single-level lumbar disc herniation. Orthop Surg. 2022;14(12):3300–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Spahn G, Ramadani M, Günther S, et al. Measurement of intervertebral disc heights in the lumbar spine. Comparison of X-ray and magnetic resonance imaging, method of measurement and determination of inter-observer reliability. Z Orthop Unfall. 2024;162(3):254–62. [DOI] [PubMed] [Google Scholar]
- 22.Lee YS, Lee SB, Kim J, et al. Semi-circumferential decompression: total en-bloc ligamentum flavectomy to treat lumbar spinal stenosis with two-level degenerative spondylolisthesis. Spine Surg Relat Res. 2020;5(2):91–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Choi SS, Ahn G, Jang IT, et al. Clinical and radiological outcomes of full-endoscopic decompression for lumbar spinal stenosis with grade I degenerative spondylolisthesis: a retrospective study with a minimum 1-year follow-up. Neurosurgery Practice. 2024;5(1):e00078. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Xu Q, Lu Z, Chen P, et al. Acceptable fusion rate of single-level OLIF using pure allograft combined with posterior instrumentation through the Wiltse approach: a 2-year follow-up study. Orthop Surg. 2023;15(3):801–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Kina H, Apaydin AS. Endoscopic or microscopic discectomy: which one do neurosurgeons prefer for their own lumbar disc surgery? Turk Neurosurg. 2025;35(5):721–6. [DOI] [PubMed] [Google Scholar]
- 26.Ambrosio L, Muthu S, Cho SK, et al. Open versus minimally invasive spine surgery in the treatment of single-level degenerative lumbar spondylolisthesis: an AO spine global cross-sectional study. Neurospine. 2025;22(1):40–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Apaydin AS, Bozyiğit B, Koç-Apaydin Z, et al. Effects of different surgical treatments on pain, disability, anxiety and quality of life in lumbar disc herniation. Cir Cir. 2024;92(1):39–45. [DOI] [PubMed] [Google Scholar]
- 28.Wang Q, Chang S, Dong JF, et al. Comparing the efficacy and complications of unilateral biportal endoscopic fusion versus minimally invasive fusion for lumbar degenerative diseases: a systematic review and mate-analysis. Eur Spine J. 2023;32(4):1345–57. [DOI] [PubMed] [Google Scholar]
- 29.Peng J, Lin RZ, Fang DP, et al. Learning curve insights in unilateral biportal endoscopic (UBE) spinal procedures: proficiency cutoffs and the impact on efficiency and complications. Eur Spine J. 2025;34:954–73. [DOI] [PubMed] [Google Scholar]
- 30.Kim DG, Park EJ, et al. Comparison of hidden blood loss in biportal endoscopic spine surgery and open surgery in the lumbar spine: a retrospective multicenter study. J Clin Med. 2025;14(11):3878. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Zhan Y, Yang F, Ye Z, et al. Comparative analysis of the efficacy and functional recovery of unilateral biportal endoscopy-assisted lumbar interbody fusion for the treatment of lumbar disc herniation. Sci Rep. 2025;15(1):41924. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Fan SW, Hu ZJ, Fang XQ, et al. Comparison of paraspinal muscle injury in one-level lumbar posterior inter-body fusion: modified minimally invasive and traditional open approaches. Orthop Surg. 2010;2(3):194–200. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Kaen A, Park MK, Son SK. Clinical outcomes of uniportal compared with biportal endoscopic decompression for the treatment of lumbar spinal stenosis: a systematic review and meta-analysis. Eur Spine J. 2023;32(8):2717–25. [DOI] [PubMed] [Google Scholar]
- 34.Dou C, Yu Q, Zhang W, et al. Comparison of biportal endoscopic technique and conventional unilateral laminectomy for bilateral decompression (ULBD) for multi-level degenerative lumbar spinal stenosis in elderly people. Orthop Surg. 2025;17(8):2302–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Gatam AR, Gatam L, Mahadhipta H, et al. Unilateral biportal endoscopic lumbar interbody fusion: a technical note and an outcome comparison with the conventional minimally invasive fusion. Orthop Res Rev. 2021;13:229–39. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Liang J, Lian L, Liang S, et al. Efficacy and complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: a meta-analysis and systematic review. World Neurosurg. 2022;159:91–102. [DOI] [PubMed] [Google Scholar]
- 37.Othman YA, Alhammoud A, Aldahamsheh O, et al. Minimally invasive spine lumbar surgery in obese patients: a systematic review and meta-analysis. HSS J. 2020;16(2):168–76. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Huang J, Rabin EE, Stricsek GP, et al. Outcomes and complications of minimally invasive transforaminal lumbar interbody fusion in the elderly: a systematic review and meta-analysis. J Neurosurg Spine. 2021;36(5):741–52. [DOI] [PubMed] [Google Scholar]
- 39.Palepu V, Helgeson MD, Molyneaux-Francis M, et al. The effects of bone microstructure on subsidence risk for ALIF, LLIF, PLIF, and TLIF spine cages. J Biomech Eng. 2019;141(3):031002. [DOI] [PubMed] [Google Scholar]
- 40.Wu H, Shan Z, Zhao F, et al. Poor bone quality, multilevel surgery, and narrow and tall cages are associated with intraoperative endplate injuries and late-onset cage subsidence in lateral lumbar interbody fusion: a systematic review. Clin Orthop Relat Res. 2022;480(1):163–88. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Eskandar T, Ahmed Z, Pan J, et al. The decline of lumbar artificial disc replacement. J Spine Res Surg. 2024;6(3):86–92. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Güneş M, Apaydın AS, Keski NNK. Investigation of lumbar multifidus muscle, pain, and fear of falling in patients with lumbar spinal stenosis with poor balance. Clin Neurol Neurosurg. 2024;246:108578. [DOI] [PubMed] [Google Scholar]
- 43.Zhang X, Yuan Q, Zhang Y, et al. Comparison of mid-term outcomes between unilateral biportal endoscopic and minimally invasive transforaminal lumbar interbody fusion in the treatment of single-level lumbar degenerative disease. PLoS ONE. 2025;20(4):e0321569. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Feeley A, McDonnell J, Feeley I, et al. Obesity: an independent risk factor for complications in anterior lumbar interbody fusion? A systematic review. Glob Spine J. 2022;12(8):1894–903. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Shi H, Zhou ZM, Xu ZY, et al. Risk factors for increased surgical drain output after transforaminal lumbar interbody fusion. World Neurosurg. 2021;151:1044–50. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data in this study are available on request from the corresponding author.