Are the facet joint parameters risk factors for cage subsidence after TLIF in patients with lumbar degenerative spondylolisthesis?

PURPOSE: To assess whether preoperative facet joint parameters in patients with degenerative lumbar spondylolisthesis (DS) are risk factors for cage subsidence (CS) following transforaminal lumbar interbody fusion (TLIF). METHODS: We enrolled 112 patients with L4-5 DS who underwent TLIF and were followed up for > 1 year. Preoperative demographic characteristics, functional areas of paraspinal muscles and psoas major muscles (PS), total functional area relative to vertebral body area, functional cross-sectional area (FCSA) of PS and lumbar spine extensor muscles, normalized FCSA of PS to the vertebral body area (FCSA/VBA), lumbar indentation value, facet joint orientation, facet joint tropism (FT), cross-sectional area of the superior articular process (SAPA), intervertebral height index, vertebral Hounsfield unit (HU) value, lordosis distribution index, t-scores, sagittal plane parameters, visual analog scale (VAS) for low back pain, VAS for leg pain, Oswestry disability index, global alignment and proportion score and European quality of life-5 dimensions (EQ-5D) were assessed. RESULTS: Postoperative CS showed significant correlations with preoperative FO(L3-4), FT (L3 and L5), SAPA(L3-5), L5-HU, FCSA/VBA(L3-4), Pre- T-score, post-6-month VAS for back pain and EQ-5D scores among other factors. According to ROC curve analysis, the optimal decision points for FO(L3-4), L3-SAPA, FCSA/VBA(L3-4), L5-HU, and Pre- T-score were 35.88°, 43.76°,114.93, 1.73, 1.55, 136, and - 2.49. CONCLUSIONS: This study identified preoperative FO, SAPA, preoperative CT, Pre- T-score and the FCSA/VBA as independent risk factors for CS after TLIF for DS. These risk factors should enable spinal surgeons to closely monitor and prevent the occurrence of CS.

Georg Schmorl Prize of the German Spine Society (DWG) 2023: the influence of sarcopenia and paraspinal muscle composition on patient-reported outcomes: a prospective investigation of lumbar spinal fusion patients with 12-month follow-up.

PURPOSE: This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12 M-FU). METHODS: A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12 months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs. RESULTS: 135 patients (52.6% female, 62.1 years, BMI 29.1 kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12 M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12 M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (ß = 0.442; p = 0.012) and lower FI of the psoas (ß = -0.439; p = 0.029) were associated with a worse ODI at 12 M-FU after adjusting for covariates. CONCLUSIONS: Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion.

The association between lumbar paraspinal muscle functional cross-sectional area on MRI and regional volumetric bone mineral density measured by quantitative computed tomography.

Osteosarcopenia is a common condition among elderly and postmenopausal female patients. Site-specific bone mineral density is more predictive of bone-related complications. Few studies have investigated muscle-bone associations. Our results demonstrated that in women, significant positive associations between paraspinal muscles FCSA and vBMD exist at different lumbosacral levels. These regional differences should be considered when interpreting bone-muscle associations in the lumbar spine. INTRODUCTION: There is increasing evidence between bone and muscle volume associations. Previous studies have demonstrated comorbidity between osteoporosis and sarcopenia. Recent studies showed that sarcopenic subjects had a fourfold higher risk of concomitant osteoporosis compared to non-sarcopenic individuals. Although site-specific bone mineral density (BMD) assessments were reported to be more predictive of bone-related complications after spinal fusions than BMD assessments in general, there are few studies that have investigated level-specific bone-muscle interactions. The aim of this study is to investigate the associations between muscle functional cross-sectional area (FCSA) on magnetic resonance imaging (MRI) and site-specific quantitative computed tomography (QCT) volumetric bone mineral density (vBMD) in the lumbosacral region among spine surgery patients. METHODS: We retrospectively reviewed a prospective institutional database of posterior lumbar fusion patients. Patients with available MRI undergoing posterior lumbar fusion were included. Muscle measurements and FCSA were conducted and calculated utilizing a manual segmentation and custom-written program at the superior endplate of the L3-L5 vertebrae level. vBMD measurements were performed and calculated utilizing a QCT pro software at L1-L2 levels and bilateral sacral ala. We stratified by sex for all analyses. RESULTS: A total of 105 patients (mean age 61.5 years and 52.4% females) were included. We found that female patients had statistically significant lower muscle FCSA than male patients. After adjusting for age and body mass index (BMI), there were statistically significant positive associations between L1-L2 and S1 vBMD with L3 psoas FCSA as well as sacral ala vBMD with L3 posterior paraspinal and L5 psoas FCSA. These associations were not found in males. CONCLUSIONS: Our results demonstrated that in women, significant positive associations between the psoas and posterior paraspinal muscle FCSA and vBMD exist in different lumbosacral levels, which are independent of age and BMI. These regional differences should be considered when interpreting bone and muscle associations in the lumbar spine.

Quantitative analysis of paraspinal muscle atrophy after oblique lateral interbody fusion alone vs. combined with percutaneous pedicle screw fixation in patients with spondylolisthesis.

BACKGROUND: There is no available literature for comparison on muscle atrophy between the "stand-alone" oblique lateral interbody fusion (OLIF) and regular OLIF (i.e., combined with percutaneous pedicle screws fixation (PPSF) in patients with spondylolisthesis). This study aimed to identify changes in back muscle atrophy between the two surgeries. METHODS: This was a retrospective cohort study of patients who underwent OLIF or OLIF+PPSF at Beijing Jishuitan Hospital and Shanghai ChangZheng Hospital between 07/2014 and 10/2017. Computed tomography (CT) was used to measure functional cross-sectional area (FCSA) and fat infiltration percentage (FIP) of the multifidus and erector spinae before and 24 months after surgery. RESULT: There were no differences in FCSA and FIP between OLIF (n = 32) and OLIF+PPSF (n = 41) groups before surgery. In the OLIF group, the multifidus and erector spinae FCSA and FIP did not change at 24 months (FCSA: multifidus: from 8.59 ± 1.76 to 9.39 ± 1.74 cm2, P = 0.072; erector spinae: from 13.32 ± 1.59 to 13.55 ± 1.31 cm2, P = 0.533) (FIP: multifidus: from 15.91 ± 5.30% to 14.38 ± 3.21%, P = 0.721; erector spinae: from 11.63 ± 3.05% to 11.22 ± 3.12%, P = 0.578). In the OLIF+PPSF group, the multifidus and erector spinae FCSA decreased (multifidus: from 7.72 ± 2.69 to 5.67 ± 1.71 cm2, P < 0.001; erector spinae: from 12.60 ± 2.04 to 10.15 ± 1.82 cm2, P < 0.001), while the FIP increased (multifidus: from 16.13 ± 7.01% to 49.38 ± 20.54%, P < 0.001; erector spinae: from 11.93 ± 3.22% to 22.60 ± 4.99%, P < 0.001). The differences of FCSA and FIP between the two groups at 24 months were significant (all P < 0.001). The patients in the standalone OLIF group had better VAS back pain, and JOA scores than the patients in the OLIF combined group (all P < 0.05) at 1 week and 3 months after surgery. There were two cases (4.9%) of adjacent segment degeneration in the OLIF combined group, while there was no case in the OLIF alone group. CONCLUSIONS: Standalone OLIF had better clinical outcomes at 1 week and 3 months than OLIF+PPSF in patients with spondylolisthesis. OLIF may not result in paraspinal muscle atrophy at 24 months after surgery.

Association patterns between lumbar paraspinal muscles and sagittal malalignment in preoperative patients undergoing lumbar three-column osteotomy.

PURPOSE: We aim to investigate the associations between lumbar paraspinal muscles and sagittal malalignment in patients undergoing lumbar three-column osteotomy. METHODS: Patients undergoing three-column osteotomy between 2016 and 2021 with preoperative lumbar magnetic resonance imaging (MRI) and whole spine radiographs in the standing position were included. Muscle measurements were obtained using a validated custom software for segmentation and muscle evaluation to calculate the functional cross-sectional area (fCSA) and percent fat infiltration (FI) of the m. psoas major (PM) as well as the m. erector spinae (ES) and m. multifidus (MM). Spinopelvic measurements included pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L1-S1 lordosis (LL), T4-12 thoracic kyphosis (TK), spino-sacral angle (SSA), C7-S1 sagittal vertical axis (SVA), T1 pelvic angle (TPA) and PI-LL mismatch (PI - LL). Statistics were performed using multivariable linear regressions adjusted for age, sex, and body mass index (BMI). RESULTS: A total of 77 patients (n = 40 female, median age 64 years, median BMI 27.9 kg/m2) were analyzed. After adjusting for age, sex and BMI, regression analyses demonstrated that a greater fCSA of the ES was significantly associated with greater SS and SSA. Moreover, our results showed a significant correlation between a greater FI of the ES and a greater kyphosis of TK. CONCLUSION: This study included a large patient cohort with sagittal alignment undergoing three-column osteotomy and is the first to demonstrate significant associations between the lumbar paraspinal muscle parameters and global sagittal alignment. Our findings emphasize the importance of the lumbar paraspinal muscles in sagittal malalignment.

The Morphological Evaluation of the Cervical Muscle in Patients With Basilar Invagination: A Magnetic Resonance Imaging-Based Study.

OBJECTIVE: To investigate the characteristics of functional muscle and muscle size in patients with basilar invagination (BI) and explore the effects of atlantoaxial dislocation. METHODS: Eighty BI patients (BI group) and 80 age- and sex-matched asymptomatic people (control group) were included. Axial T2 magnetic resonance imaging image was used to measure the cross-sectional area (CSA) and functional CSA (FCSA). The sternocleidomastoid (SCM), longus capitis and longus colli (LCap & LC), trapezius (Trap), splenius capitis (SpCap), splenius cervicis (SpC), semispinalis capitis (SSCap), semispinalis cervicis (SSC), multifidus (MS), levator scapulae (LS) and posterior deep layer muscles (PDLM) were evaluated. Correlations between age, atlantodental interval (ADI), Chamberlain distance and muscles were observed. RESULTS: BI group (39.4 ± 18.4 years; 33 males/47 females) exhibited significantly lower FCSA/CSA ratios than the control group in all extensor and flexor muscles, and presented smaller CSAs on the right and left Trap, SSC, LS, SCM, and left LCap & LC. FCSA/CSA ratios were significantly lower in BI patients with dislocation on the right Trap, SpCap, SpC, SSCap, MS, LS, LCap & LC, and PDLM, and the left SSCap, MS, and LCap & LC than in patients without deformity. Additionally, functional muscles of all parameters decreased with age in BI patients. Excluding children, the Trap, SpC, MS, and LS muscle sizes of BI patients tended to increase with age. ADI and Chamberlain distance tended to correlate negatively with FCSA/CSA ratio. CONCLUSION: The BI patients, especially those with atlantoaxial dislocation, had less functional muscles compared with the control group. Moreover, their functional muscles decreased with age more obviously.

Changes in paraspinal muscles and facet joints after percutaneous endoscopic transforaminal lumbar interbody fusion for the treatment of lumbar spinal stenosis: A 3-year follow-up.

Objectives: This study investigates the changes in the paraspinal muscles of lumbar spinal stenosis patients after percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF). Methods: Thirty-three patients from Beijing Chaoyang Hospital who had L4/5 segment lumbar spinal stenosis between January, 2017 and January, 2019were included in this study. Patient-reported outcomes including the visual analog scale scores for back pain and leg pain (VAS-BP and VAS-LP, respectively) and the Oswestry disability index (ODI) scores at pre-operation and 1-week, 3-month, 12-month, and (at least) 3-year follow-up (the final follow-up) were evaluated. Computed tomography (CT) was performed at the 12-month follow-up, 24-month follow-up, and the final follow-up after surgery. Multifidus (MF) muscle functional cross-sectional area (FCSA) and fat infiltration (FI) were evaluated, and the degree of adjacent facet joint degeneration was evaluated using Pathria scores. Results: All patients underwent at least a 3-year follow-up period. The VAS-BP, VAS-LP, and ODI were significantly lower at 1-week, 3-month, 12-month, and 3-year follow-up than at pre-operation (P < 0.05). At the 3-year follow-up, no differences were found in FCSA and FI for any patient's MF muscle at the lower third of the vertebral body (L3) above the operation level (P > 0.05), and there was no statistical difference in the central plane of the L3/4 and L5/S1 vertebral facet joints at pre-operation, 12-month, 24-month, and 3-month follow-up (P > 0.05). Conclusions: PE-TLIF can provide satisfactory clinical outcomes for patients with lumbar spinal stenosis. Furthermore, the technique may also reduce the injury on the paravertebral muscles, especially the MF muscle, as well as on adjacent facet joints.

Assessment of Paraspinal Muscle Atrophy Percentage after Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Instrumentation Using a Novel Contralateral Intact Muscle-Controlled Model.

STUDY DESIGN: Retrospective comparative clinical study. PURPOSE: This study aimed to assess paraspinal muscle atrophy in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and unilateral pedicle screw fixation using a novel contralateral intact muscle-controlled model. OVERVIEW OF LITERATURE: The increased incidence of paravertebral lumbar muscle injuries after open techniques has raised the importance of implementing minimally invasive spine surgical techniques using tubular retractors and minimally invasive screw placement. The functional cross-sectional area (FCSA) represents the lean muscle mass; furthermore, FCSA is a useful marker of the contractile ability of a muscle following a spine surgery. However, the benefits of unilateral fixation and MI-TLIF on paraspinal muscles have not been defined. METHODS: We performed a retrospective imagenological review on eleven patients who underwent unilateral MI-TLIF and unilateral transpedicular screw lumbar placement. FCSAs of the multifidus and erector spinae were measured 1 year after surgery at adjacent levels and were compared to the contralateral intact muscles. Measurement differences between the surgical and nonsurgical sites were compared. The interobserver reliability was calculated using an intraclass correlation coefficient. RESULTS: The mean FCSA at the surgical site was 20.97±5.07 cm2 at the superior level and 8.89±2.87 cm2 at the inferior level. The mean FCSA at the contralateral nonsurgical site was 20.15±5.95 cm2 at the superior level and 9.20±2.66 cm2 at the inferior level was. The superior and inferior FCSA measurements showed no significant difference between the surgical and nonsurgical sites (p=0.5, p=0.922, respectively). CONCLUSIONS: Using a mini-open tubular approach through the sulcus between the longissimus and iliocostalis, MI-TLIF and unilateral pedicle screw instrumentation produced minimal paraspinal muscle damage at the superior and inferior adjacent levels.

Relationship between cervical muscle morphology evaluated by MRI, cervical muscle strength and functional outcomes in patients with degenerative cervical myelopathy.

BACKGROUND: Cervical muscle alterations have been reported in patients with chronic neck pain, but the assessment of muscle morphology and strength has been overlooked in patients with degenerative cervical myelopathy (DCM). OBJECTIVES: This study aimed to investigate the relationship between cervical muscle degenerative changes observed on MRI, muscle strength and symptoms severity in patients diagnosed with DCM. DESIGN: Observational study. METHODS: Cervical muscle measurements of total cross-sectional area (CSA), functional CSA (fat free area, FCSA) and ratio of FCSA/CSA (e.g. fatty infiltration) were obtained from T2-weighted axial MR images from C2-C3 to C6-C7 in 20 patients. Muscle strength was assessed manually using a microFET2 dynamometer. The association between cervical muscle morphology parameters, muscle strength, symptoms severity and functional status was investigated. RESULTS: Greater mean CSA and FCSA was associated with greater overall muscle strength. The mean FCSA explained 37%, 76%, 39%, 20% and 65% of the total variance in flexion, extension, right-side bending, left-side bending and overall muscle strength, respectively. The mean ratio of FCSA/CSA was not significantly associated with cervical muscle strength in any direction. However, greater FCSA/CSA ratio (e.g. less fatty infiltration) was associated with lower disability score (p = 0.02, R2 = 0.20). CONCLUSIONS: Cervical muscle lean muscle mass was positively associated with cervical muscle strength in patients with DCM. Moreover, greater fatty infiltration in the cervical extensor muscles was associated with lower functional score. Such findings suggest that clinicians should pay greater attention to cervical muscle morphology and function in patients with DCM.