Sleep and Quality of Life Before and After Surgery in Patients With Low-Grade Lumbar Spondylolisthesis

Introduction

Spondylolisthesis (SL) is defined as the anterior displacement of one vertebra over another [1]. The term “spondylolisthesis” was first introduced by Kilian in 1854 [2]. The Wiltse-Newman-McNab classification, which remains widely used today, was developed in 1976 and categorizes spondylolisthesis into 6 types: isthmic, degenerative, dysplastic, traumatic, iatrogenic, and pathological [3]. According to the Meyerding classification, which assesses the degree of vertebral slippage, spondylolisthesis is divided into 5 grades: Grade 1 (<25%), Grade 2 (25–50%), Grade 3 (50–75%), Grade 4 (75–100%), and Grade 5 (spondyloptosis, >100%) [4]. Low-grade spondylolisthesis is defined as vertebral slippage not exceeding 50%, encompassing Grade I (0–25%) and Grade II (25–50%) according to the Meyerding classification [5].

The prevalence of spondylolisthesis in the general population is estimated to be between 4% and 6% [6]. Etiologically, the most common form is isthmic spondylolisthesis (IS), which occurs approximately twice as often in men compared to women [7]. Degenerative spondylolisthesis (DS), in contrast, is characterized not solely by vertebral slippage, but by thickening of the joint capsules and ligaments, hypertrophy of the facet joints, narrowing of the lateral recesses, and compression of nerve roots within the neural foramina [8]. DS is particularly prevalent among women over the age of 50 years [9].

Spondylolisthesis (SL) can manifest across a wide clinical spectrum, ranging from simple mechanical low back pain to progressive neurological deficits and significant radiological findings [10]. Regardless of its etiology, pain is the most common symptom. This pain typically radiates to the lower back and legs and is a major factor contributing to poor sleep quality. Pain reduces sleep quality, and disrupted sleep, in turn, amplifies the perception of pain, creating a vicious cycle [11]. Impaired sleep quality adversely affects not only physical health, but also psychological well-being, work productivity, and overall quality of life [12].

Few studies have systematically assessed preoperative and postoperative sleep quality in patients diagnosed with low-grade lumbar spondylolisthesis and treated surgically. This study aims to contribute to this gap in the literature by evaluating not only pain and quality of life, but also sleep quality and daily living activities within a homogeneous patient population.

Material and Methods

STUDY DESIGN:

This prospective, multicenter, observational study was conducted between August 16, 2024, and December 2024 at Çorum Hitit University, Ordu University, and Siirt Training and Research Hospital. A total of 55 patients diagnosed with low-grade lumbar spondylolisthesis who underwent the same surgical proceedure were included. Posterior decompression combined with instrumented fusion was performed as the surgical technique at all participating centers. Our indications for lumbar spondylolisthesis surgery include patients with radicular pain, muscle weakness, leg pain unresponsive to conservative treatment, neurogenic claudication, and radiographically confirmed listhesis on dynamic imaging.

INCLUSION AND EXCLISION CRITERIAS:

The inclusion criteria for this study were as follows: patients with grade 1–2 spondylolisthesis according to the Meyerding classification; isthmic (IS) or degenerative (DS) spondylolisthesis based on the Wiltse, Newman, and MacNab classification; single-level vertebral slippage; no prior history of spinal surgery; presence of radicular pain and muscle weakness; absence of trauma-related spondylolisthesis; age over 18 years; no evidence of spinal infection or spinal tumor on imaging; body mass index less than 30 kg/m²; T-score above −2.5 on bone mineral densitometry; lack of clinical response to conservative treatment; and availability of dynamic radiographs, lumbar computed tomography (CT), and lumbar magnetic resonance imaging (MRI) prior to the preoperative assessment. The exclusion criteria for this study were as follows: patients with grade 3–4 spondylolisthesis according to the Meyerding classification; types of spondylolisthesis other than IS and DS as per the Wiltse, Newman, and MacNab classification; those with multi-level slippage; postoperative spondylolisthesis following spinal surgery; trauma-induced spondylolisthesis; individuals under 18 years of age; presence of spinal infection or radiological evidence of spinal tumors; body mass index greater than 30 kg/m²; T-score below −2.5 on bone mineral densitometry; patients who responded positively to conservative treatment; those with sleep apnea, advanced heart failure, pulmonary disease or pathology, psychiatric disorders or use of psychiatric medication; night-shift workers; and those lacking preoperative dynamic radiographs, lumbar CT, or lumbar MRI.

After providing written informed consent, participants completed the survey forms at 2 time points: the first before surgery and the second during their follow-up visit to the neurosurgery clinic on postoperative day 90. The questionnaires were administered face-to-face by the researchers. Written consents obtained for data confidentiality and the protection of personal data were archived in an appropriate environment. The sample size was calculated using the G*Power v3.1 program (Heinrich-Heine-Universität Düsseldorf), based on the formula for comparing 2 dependent means, with an alpha error of 0.05, a power of 90%, and an effect size of 0.5, resulting in a minimum required sample of 38 participants. Individuals who voluntarily agreed to participate and completed both assessments in full were included in the study.

DATA COLLECTION TOOLS:

In this study, a total of 55 patients were evaluated using the following instruments both preoperatively and on the 90^th postoperative day: the Visual Analog Scale (VAS), Pittsburgh Sleep Quality Index (PSQI), EuroQol-5 Dimension Questionnaire (EQ-5D-3L), and Oswestry Disability Index (ODI).

In the first section, participants’ demographic and clinical characteristics were recorded, including age, sex, level of listhesis, etiology of spondylolisthesis, and the degree of slippage according to the Meyerding classification.

In the second section, pain intensity was assessed using the VAS. Participants rated the severity of their low back pain on a scale from 0 (no pain) to 10 (worst possible pain) [13].

In the third section, the PSQI was used to assess sleep quality. The PSQI consists of 24 items and 7 components. Of the 24 items, 19 are self-rated by the participant and are included in the scoring, while the remaining 5 are answered by a roommate or bed partner but are not used in the scoring process. The 19 scored items are grouped into 7 components, each rated on a scale from 0 to 3. The total PSQI score is the sum of these component scores, ranging from 0 to 21, with higher scores indicating poorer sleep quality. Although the PSQI does not diagnose specific sleep disorders, a global score of 5 or higher is indicative of poor sleep quality. The PSQI was developed by Buysse et al in 1989, and its Turkish validity and reliability were established by Ağargün et al in 1996 [14,15].

In the fourth section, the EQ-5D-3L Generic Quality of Life Scale was used to assess quality of life. This scale consists of 5 dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is scored as 1 (no problems), 2 (some problems), or 3 (extreme problems). The total score ranges from −0.59 to 1, where a score of 1 indicates perfect health and 0 represents death. Negative values reflect health states worse than death, such as unconsciousness or complete dependency. The EQ-5D-3L was developed by the EuroQol Group in 1987 [16] and has since been translated into more than 60 languages, including Turkish. In this study, the scoring system was based on the value set provided by Golicki et al [17].

In the fifth section, the ODI was used to evaluate how much low back pain affects daily activities. The scale assesses disability across 10 aspects of daily life: pain intensity, personal care, lifting, walking, sitting, standing, sleeping, sexual activity (if applicable), social life, and traveling. Each item includes 6 statements scored from 0 to 5, where 0 indicates no disability and 5 indicates maximum disability. The total score is expressed as a percentage, with 0% representing no disability and 100% representing the highest level of disability. The ODI was developed by Jeremy Fairbank and Graham Pynsent in 1980 in Oswestry, England [18], and is considered one of the most reliable tools for assessing low back pain-related disability [19]. The Turkish version was validated and adapted by Yakut et al in 2004 [20].

STATISTICAL ANALYSIS:

All statistical analyses were performed using IBM SPSS version 25 (IBM Corp, Armonk, NY, USA). Descriptive statistics, including frequency, percentage, mean, and standard deviation, were used to summarize participant characteristics. Since the data were not normally distributed, the Wilcoxon signed-rank test was applied to compare preoperative and postoperative scores for sleep quality, pain intensity, daily living activities, and quality of life. The Mann-Whitney U test was used to compare changes in sleep quality, pain, quality of life, and daily activity scores across groups based on age, sex, and diagnosis. Spearman correlation analysis was conducted to assess relationships among continuous variables. Subgroup analyses were performed to evaluate score improvements in EQ-5D-3L, PSQI, VAS, and ODI based on etiology and sex. A P value of <0.05 was considered statistically significant.

:

Ethics approval was received from the Hitit University Ethics Committee in accordance with the Helsinki Declaration, with the decision number 2024/53 dated 15 August 2024.

Results

Of the 55 patients, 47 (85.5%) were female, with a mean age of 59.9±8.2 years. Spondylolisthesis was located at L3–L4 in 5.5%, L4–L5 in 60.0%, and L5–S1 in 34.5% of cases. Degenerative spondylolisthesis accounted for 45.5% of cases, and 50.9% were classified as grade 1 according to the Meyerding system. Detailed demographic and clinical characteristics, including age, spondylolisthesis level, etiology, and grade, are summarized in Table 1.

Postoperatively, PSQI, VAS, and ODI scores significantly decreased, while EQ-5D-3L scores markedly improved (all P<0.001). The comparison of preoperative and postoperative day 90 scores for PSQI, VAS, ODI, and EQ-5D-3L in all participants is presented in Table 2.

Improvements in VAS, ODI, and EQ-5D-3L did not differ significantly between DS and IS, or across spondylolisthesis grades (all P>0.05). Male patients showed greater improvement in EQ-5D-3L than females (P=0.037). Table 3 compares improvements in EQ-5D-3L, PSQI, VAS, and ODI scores between the preoperative period and postoperative day 90, based on spondylolisthesis etiology, sex, and grade.

In subgroup analysis, male patients with IS showed greater improvements in EQ-5D-3L and PSQI than those with DS (P=0.015), whereas in females, VAS improvement was greater in DS than IS (P=0.024). A detailed comparison of EQ-5D-3L, PSQI, VAS, and ODI score improvements by spondylolisthesis etiology within male and female subgroups is presented in Table 4.

Discussion

LIMITATIONS:

This study has several limitations. First, as only patients who met the surgical indication criteria were included, follow-up with conservative treatment was not possible and a control group could not be established. Second, although the overall sample size met the minimum requirement determined by power analysis, the limited distribution of cases within certain subgroups based on etiology and sex may have reduced the statistical power of subgroup comparisons. Finally, the study focused on short-term outcomes, and future research with larger cohorts and longer follow-up is warranted to validate and expand upon these findings.

Conclusions

This study demonstrated that surgical intervention in patients with low-grade lumbar spondylolisthesis leads to significant improvements in pain, quality of life, daily functional capacity, and particularly sleep quality.

In patients who do not respond to conservative treatment, develop muscle weakness, experience reduced walking distance, and present with high preoperative scores on evaluation scales, appropriately indicated surgical treatment not only promotes functional recovery but also enhances overall quality of life.

The relief of pain and improvement in sleep quality provide important contributions to maintaining general health and sustaining quality of life. These findings suggest that surgery may offer not only physical benefits but also improve patients’ psychosocial well-being.