Regenerative therapies for lumbar degenerative disc diseases: a literature review.

This review aimed to summarize the recent advances and challenges in the field of regenerative therapies for lumbar disc degeneration. The current first-line treatment options for symptomatic lumbar disc degeneration cannot modify the disease process or restore the normal structure, composition, and biomechanical function of the degenerated discs. Cell-based therapies tailored to facilitate intervertebral disc (IVD) regeneration have been developed to restore the IVD extracellular matrix or mitigate inflammatory conditions. Human clinical trials on Mesenchymal Stem Cells (MSCs) have reported promising outcomes exhibited by MSCs in reducing pain and improving function. Nucleus pulposus (NP) cells possess unique regenerative capacities. Biomaterials aimed at NP replacement in IVD regeneration, comprising synthetic and biological materials, aim to restore disc height and segmental stability without compromising the annulus fibrosus. Similarly, composite IVD replacements that combine various biomaterial strategies to mimic the native disc structure, including organized annulus fibrosus and NP components, have shown promise. Furthermore, preclinical studies on regenerative medicine therapies that utilize cells, biomaterials, growth factors, platelet-rich plasma (PRP), and biological agents have demonstrated their promise in repairing degenerated lumbar discs. However, these therapies are associated with significant limitations and challenges that hinder their clinical translation. Thus, further studies must be conducted to address these challenges.

Artificial Intelligence-Assisted MRI Diagnosis in Lumbar Degenerative Disc Disease: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVES: Lumbar degenerative disc disease (DDD) poses a significant global health care challenge, with accurate diagnosis being difficult using conventional methods. Artificial intelligence (AI), particularly machine learning and deep learning, offers promising tools for improving diagnostic accuracy and workflow in lumbar DDD. This study aims to review AI-assisted magnetic resonance imaging (MRI) diagnosis in lumbar DDD and discuss current research for clinical use. METHODS: A systematic search of electronic databases identified studies on AI applications in MRI-based lumbar DDD diagnosis, following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Search terms included combinations of "Artificial Intelligence," "Machine Learning," "Deep Learning," "Low Back Pain," "Lumbar," "Disc," "Degeneration," and "MRI," targeting studies in English from January 1, 2010, to January 1, 2024. Inclusion criteria encompassed experimental and observational studies in peer-reviewed journals. Data extraction focused on study characteristics, AI techniques, performance metrics, and diagnostic outcomes, with quality assessed using predefined criteria. RESULTS: Twenty studies met the inclusion criteria, employing various AI methodologies, including machine learning and deep learning, to diagnose lumbar DDD manifestations such as disc degeneration, herniation, and bulging. AI models consistently outperformed conventional methods in accuracy, sensitivity, and specificity, with performance metrics ranging from 71.5% to 99% across different diagnostic objectives. CONCLUSION: The algorithm model provides a structured framework for integrating AI into routine clinical practice, enhancing diagnostic precision and patient outcomes in lumbar DDD management. Further research and validation are needed to refine AI algorithms for real-world application in lumbar DDD diagnosis.

Association of TaqI (rs731236) Polymorphism of Vitamin D Receptor Gene with Lumbar Degenerative Disc Disease.

BACKGROUND: Lumbar degenerative disc disease (LDDD) significantly contributes to low back pain, with a complicated etiology involving genetic and environmental facts. The aim of study was to investigate the association between the TaqI (rs731236) polymorphism of the vitamin D receptor (VDR) gene with LDDD. METHODS: In total, 248 patients with symptomatic LDDD and 146 control subjects were examined. The evaluation of clinical features of patients with LDDD comprised radiodiagnostic magnetic resonance imaging, neurologic examinations, pain scores including the visual analog scale (VAS), and disability investigation with Oswestry Disability Index (ODI). Genotyping of the VDR gene polymorphism was conducted using polymerase chain reaction-based methods. RESULTS: Individuals of the LDDD group who were VDR TaqI AA genotype carriers were significantly greater than the other group (P = 0.014), whereas those with GG genotype were significantly lower (P = 0.028) in the patient group. In addition, VAS and ODI scores were significantly lower in the GG genotype carrier group, whereas AA genotype carriers had the greatest scores (P = 0.004). Carrying the G allele decreased the risk of LDDD 1.7 times (P = 0.014) and carrying the A allele enhanced the risk 1.8 times (P = 0.028). Moreover, G-allele carriers had significantly lower VAS (P = 0.002) and ODI scores (P < 0.0001). CONCLUSIONS: VDR TaqI (rs731236) GG genotype and G allele have protective potential, whereas the AA genotype and A allele are risk factors for LDDD. The findings reveal a statistically significant association of the TaqI (rs731236) polymorphism of VDR gene polymorphism with LDDD. This result highlights the potential role of genetic factors in developing LDDD and suggests avenues for future research in genetic screening and personalized treatment strategies.

Risk Factors for Surgical Treatment of Lumbar Degenerative Disc Disease in Middle-aged and Older Women: A Prospective Case-Control Study of 2370 Subjects.

OBJECTIVE: Given the distinct physiological and societal traits between women and men, we propose that there are distinct risk factors for lumbar degenerative disc disease surgeries, including lumbar disc herniation (LDH) and lumbar spinal stenosis (LSS), in middle-aged and older populations. However, few studies have focused on middle-aged and older women. This study aims to identify these risk factors specifically in this population. METHODS: In this case-control study, the study group comprised 1202 women aged ≥ 45 years who underwent operative treatment of lumbar degenerative disc disease (LDH, n = 825; LSS, n = 377), and the control group comprised 1168 women without lumbar disease who visited a health examination clinic during the same period. The study factors included demographics (age, body mass index [BMI], smoking, labor intensity, and genetic history), female-specific factors (menopausal status, number of deliveries, cesarean section, and simple hysterectomy), surgical history (number of abdominal surgeries, hip joint surgery, knee joint surgery, and thyroidectomy), and systemic diseases (hypercholesterolemia, hypertriglyceridemia, hyper-low-density lipoprotein cholesterolemia, hypertension, diabetes, cardiovascular disease, and cerebrovascular disease). Multivariate binary logistic regression analysis was used to calculate the odds ratio (OR) and 95% confidence interval (95% CI) of associated factors. RESULTS: The risk factors for surgical treatment of LDH in middle-aged and older women included BMI (OR = 1.603), labor intensity (OR = 1.189), genetic history (OR = 2.212), number of deliveries (OR = 1.736), simple hysterectomy (OR = 2.511), hypertriglyceridemia (OR = 1.932), and hyper-low-density lipoprotein cholesterolemia (OR = 2.662). For surgical treatment of LSS, the risk factors were age (OR = 1.889), BMI (OR = 1.671), genetic history (OR = 2.134), number of deliveries (OR = 2.962), simple hysterectomy (OR = 1.968), knee joint surgery (OR = 2.527), hypertriglyceridemia (OR = 1.476), hyper-low-density lipoprotein cholesterolemia (OR = 2.413), and diabetes (OR = 1.643). Cerebrovascular disease was a protective factor against surgery for LDH (OR = 0.267). CONCLUSIONS: BMI, genetic history, number of deliveries, simple hysterectomy, hypertriglyceridemia, and hyper-low-density lipoprotein cholesterolemia were independent risk factors for surgical treatment of both LDH and LSS in middle-aged and older women. Two disparities were found: labor intensity was a risk factor for LDH patients, and knee joint surgery and diabetes were risk factors for LSS patients.

Corrigendum: Study of quality of life and its correlated factors in patients after lumbar fusion for lumbar degenerative disc disease.

[This corrects the article DOI: 10.3389/fsurg.2022.939591.].

Getting what you pay for: impact of copayments on physical therapy and opioid initiation, timing, and continuation for newly diagnosed low back pain.

BACKGROUND CONTEXT: Physical therapy (PT) is an important component of low back pain (LBP) management. Despite established guidelines, heterogeneity in medical management remains common. PURPOSE: We sought to understand how copayments impact timing and utilization of PT in newly diagnosed LBP. STUDY DESIGN/SETTING: The IBM Watson Health MarketScan claims database was used in a longitudinal setting. PATIENT SAMPLE: Adult patients with LBP. OUTCOME MEASURES: The primary outcomes-of-interest were timing and overall utilization of PT services. Additional outcomes-of-interest included timing of opioid prescribing. METHODS: Actual and inferred copayments based on nonnonprimary care provider visit claims were used to evaluate the relationship between PT copayment and incidence of PT initiation. Multivariable regression models were used to evaluate factors influencing PT usage. RESULTS: Overall, 2,467,389 patients were included. PT initiation, among those with at ≥1 PT service during the year after LBP diagnosis (30.6%), occurred at a median of 8 days postdiagnosis (IQR 1-55). Among those with at least one PT encounter, incidence of subsequent PT visits was significantly lower for those with high initial PT copayments. High initial PT copayments, while inversely correlated with PT utilization, were directly correlated with subsequent opioid use (0.77 prescriptions/patient [$0 PT copayment] versus 1.07 prescriptions/patient [$50-74 PT copayment]; 1.15 prescriptions/patient [$75+ PT copayment]). Among patients with known opioid and PT copayments, higher PT copayments were correlated with faster opioid use while higher opioid copayments were correlated with faster PT use (Spearman p<.05). For multivariable whole-cohort analyses, incidence of PT initiation among patients with inferred copayments in the 50-75th and 75-100th percentiles was significantly lower than those below the 50th percentile (HR=0.893 [95%CI 0.887-0.899] and HR=0.905 [95%CI 0.899-0.912], respectively). CONCLUSIONS: Higher PT copayments correlated with reduced PT utilization; higher PT copayments and lower opioid copayments were independent contributors to delayed PT initiation and higher opioid use. In patients covered by plans charging high PT copayments, opioid use was significantly higher. Copays may impact long-term adherence to PT.

Single-Level Endoscopic TLIF Has Decreased Surgery Duration, Blood Loss, and Length of Hospital Stay While Achieving Similar 1-Year Clinical and Radiological Outcomes Compared With Conventional Minimally Invasive TLIF.

BACKGROUND: This study presents a single surgeon's experience comparing 1-year outcomes of endoscopic transforaminal lumbar interbody fusion (E-TLIF) vs minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in an Asian population. METHODS: Retrospective review of consecutive patients who underwent single-level E-TLIF or MIS-TLIF by a single surgeon in a tertiary spine institution from 2018 to 2021 with 1-year follow-up. Inclusion criteria for both procedures were degenerative disc disease with grade I or II spondylolisthesis and mild to moderate central canal stenosis. Clinical outcomes assessed included surgery duration, blood loss, and length of stay. Patient-reported outcomes assessed included the visual analog score for back pain and lower limb pain, Oswestry Disability Index, and North American Spine Society Neurogenic Symptom Score. Radiographic parameters assessed included segmental lordosis, posterior disc height, listhesis, and the presence of cage migration or subsidence. RESULTS: Twelve E-TLIF and 34 MIS-TLIF patients were identified. E-TLIF had shorter surgery duration (165 ± 15 vs 259 ± 43 min for E-TLIF and MIS-TLIF groups, respectively; P < 0.001), reduced blood loss (83 ± 75 vs 181 ± 225 mL; P = 0.033), and decreased length of stay (1.8 ± 0.9 vs 4.7 ± 2.9 days; P < 0.001) compared with MIS-TLIF. E-TLIF and MIS-TLIF patients had significant improvements (P < 0.05) at 1 year in all patient-reported outcomes scores and radiographic parameters assessed. Both E-TLIF and MIS-TLIF patient groups also had similar postoperative patient-reported outcomes scores and radiographic parameters. No complications were recorded for E-TLIF, while MIS-TLIF had a case of dura tear and another case of meralgia paresthetica. There were no instances of cage subsidence, cage migration, or implant loosening in either group at 1 year. CONCLUSIONS: Although the study size was limited because E-TLIF is a relatively new technique in our institution, 1-year results demonstrate that E-TLIF can be a safe and efficacious option that achieves clinical and radiological results similar to MIS-TLIF with the additional benefits of decreased surgical duration, blood loss, and length of hospital stay. CLINICAL RELEVANCE: The results of this study support the effectiveness and potential advantages of endoscopic TLIF compared with MIS-TLIF.

CircRNA GRB10 is a Novel Biomarker for the Accurate Diagnosis of Lumbar Degenerative Disc Disease.

Lumbar degenerative disc disease (LDDD) is frequently misdiagnosed as other spine conditions, and the accurate diagnosis is challenging. This study was conducted to explore the role of circRNA GRB10 in the accurate diagnosis of LDDD. This study included 60 cases of LDDD, 60 cases of patients with sacroiliac joint pain (SJP), 60 cases of lumbar disc herniation (LDH), 60 cases of piriformis syndrome (PS), 60 cases of entrapment neuropathy (EN) and 60 cases of healthy controls (HCs). Plasma was obtained from each patient before and after treatment. Expression of GRB10 was studied with RT-qPCR. The role of plasma GRB10 in the accurate diagnosis of LDDD was analyzed by ROC curve analysis. Compared to HCs, decreased accumulation of GRB10 RNA was only observed in LDDD group, but not in SJP, LDH, PS and EN groups. With plasma expression level of GRB10 measured before treatment as a biomarker, LDDD patients were separated from SJP, LDH, PS, EN and HC groups. After treatment, increased expression levels of GRB10 were only observed in LDDD group, but not in other groups. Therefore, GRB10 was downregulated in LDDD and may serve as a biomarker for the accurate diagnosis of LDDD.

Ceramic bone graft substitute (Mg-HA) in spinal fusion: A prospective pilot study.

Background: Iliac crest bone graft (ICBG) is considered the gold standard for spine surgical procedures to achieve a successful fusion due to its known osteoinductive and osteoconductive properties. However, complications related to harvesting procedure and donor site morbidity have been largely reported in the literature, favoring the development of a wide range of alternative products to be used as bone graft extenders or substitutes for spine fusion. Among all, ceramic-based biomaterials have been widely studied and employed in the last years as bone graft substitutes. Methods: We report here the results of a prospective pilot study aimed to evaluating the grade of ossification obtained by the use of an Mg-doped hydroxyapatite (HA) product to achieve postero-lateral fusion in degenerative spine diseases. Results: Results show a successful degree of fusion of about 62% at the 12-month follow-up and an improvement of quality of life and health status following surgery, as evaluated by clinical scores (ODI, VAS, and EQ-5L). No adverse events related to the material were reported. Conclusion: The present pilot study shows the effectiveness and the safety profile of an Mg-doped HA bone graft substitute used to achieve postero-lateral fusion in the treatment of degenerative spine diseases, laying down the basis for further larger clinical investigations.

National trends in the utilization of lumbar disc replacement for lumbar degenerative disc disease over a 10-year period, 2010 to 2019.

Background: Lumbar fusion (LF) is commonly performed to manage lumbar degenerative disc disease (LDDD) that has failed conservative measures. However, lumbar disc replacement (LDR) procedures are increasingly prevalent and designed to preserve motion in carefully selected patients. Methods: A retrospective cohort study was performed using the National Inpatient Sample (NIS), queried from 2010 to 2019 to identify patients undergoing single and double-level LF or LDR with a diagnosis of LDDD using International Classification of Diseases (ICD) 9th (ICD-9) and 10th (ICD-10) revision diagnostic and procedure codes. Propensity score matching (PSM) with a ratio of 2:1 was performed. All cost estimates reflect reported hospital costs adjusted to December 2019 United States Dollars. Results: A total of 1,129,121 LF cases (99.3%) and 8,049 LDR cases (0.7%) were identified, with 364,637 (32.3%) and 712 (8.8%) comprising two-level surgeries, respectively. 1,712 LDRs were performed in 2010 (1.27% of all), decreasing to 565 in 2013 (0.52%), and increased slightly to 870 in 2019 (0.74%). LDR patients were significantly more likely to be younger (mean age 41.2 vs. 57.1, P<0.001) and healthier (mean ECI 0.88 vs. 1.80, P<0.001). On matched analysis, LDR hospital costs were $4,529 less (P<0.001) and length of stay was 0.65 days shorter (P<0.001) than LF patients. LDR patients had lower rates of any complication (7.0% vs. 13.2%, P<0.001), neurologic complication (3.0% vs. 4.2%, P=0.006), and blood transfusion (3.1% vs. 8.1%, P<0.001) compared to LF patients. Conclusions: The prevalence of LDR procedures decreased from 2010-2017 but began to increase again in 2018 and 2019. Single-level LDR was associated with reduced costs and length of stay (LOS), and lower rates of blood transfusion compared to LF in patients with LDDD.

Predictors of long-term clinical outcomes in adult patients after lumbar total disc replacement: development and validation of a prediction model.

OBJECTIVE: Long-term outcomes of single-level lumbar arthroplasty are understood to be very good, with the most recent Investigational Device Exemption (IDE) trial showing a < 5% reoperation rate at the close of the 7-year study. This post hoc analysis was conducted to determine whether specific patients from the activL IDE data set had better outcomes than the mean good outcome of the IDE trial, as well as to identify contributing factors that could be optimized in real-world use. METHODS: Univariable and multivariable logistic regression models were developed using the randomized patient set (n = 283) from the activL trial and used to identify predictive factors and to derive risk equations. The models were internally validated using the randomized patient set and externally validated using the nonrandomized patient set (n = 52) from the activL trial. Predictive power was assessed using area under the receiver operating characteristic curve analysis. RESULTS: Two factors were significantly associated with achievement of better than the mean outcomes at 7 years. Randomization to receive the activL device was positively associated with better than the mean visual analog scale (VAS)-back pain and Oswestry Disability Index (ODI) scores, whereas preoperative narcotics use was negatively associated with better than the mean ODI score. Preoperative narcotics use was also negatively associated with return to unrestricted full-time work. Other preoperative factors associated with positive outcomes included unrestricted full-time work, working manual labor after index back injury, and decreasing disc height. Older age, greater VAS-leg pain score, greater ODI score, female sex, and working manual labor before back injury were identified as preoperative factors associated with negative outcomes. Preoperative BMI, VAS-back pain score, back pain duration ≥ 1 year, SF-36 physical component summary score, and recreational activity had no effect on outcomes. CONCLUSIONS: Lumbar total disc replacement for symptomatic single-level lumbar degenerative disc disease is a well-established option for improving long-term patient outcomes. Discontinuing narcotics use may further improve patient outcomes, as this analysis identified associations between no preoperative narcotics use and better ODI score relative to the mean score of the activL trial at 7 years and increased likelihood of return to work within 7 years. Other preoperative factors that may further improve outcomes included unrestricted full-time work, working manual labor despite back injury, sedentary work status before back injury, and randomization to receive the activL device. Tailoring patient care before total disc replacement may further improve patient outcomes.

Study of quality of life and its correlated factors in patients after lumbar fusion for lumbar degenerative disc disease.

Background: In the present work, we aimed to explore the correlated factors of quality of life in patients receiving lumbar fusion for lumbar degenerative disc disease (DDD) in China. Methods: A total of 180 patients treated with lumbar fusion were included in the present study. Their general demographic characteristics, Visual Analog Scale (VAS) scores, Japanese Orthopedic Association (JOA) scores, Simplified Coping Style Questionnaire (SCSQ), Social Support Questionnaire (SSQ), and Medical Outcomes Study Short Form 36 (MOS SF-36) were collected and evaluated preoperatively and at 1 year postoperatively. Results: There were significant improvements in scores of VAS, JOA, and quality of life of patients from preoperation to 1-year postoperation after lumbar fusion. Marital status, with or without children, education level, economic pressure, and social support had significant predictive effects on the physical health of patients undergoing lumbar fusion. Marital status, education level, and economic pressure had significant predictive effects on the mental health of patients undergoing lumbar fusion. Conclusions: Factors correlated with the physical health of patients after lumbar fusion included positive coping style, negative coping style, social support, age, education level (high school college), disease duration (5-10), suffering from other diseases (combined with two or more other disease) and the number of surgical segments (double and three or more). Factors correlated with the mental health included negative coping style, social support, age, education level (middle school and high school college) and the number of surgical segments (double and three or more). The results verify that these factors were correlated to the patient's quality of life after lumbar fusion. Emphasizing and selectively intervening these correlated factors can further improve the quality of life in patients receiving lumbar fusion for lumbar degenerative disc disease.

Multicenter Retrospective Review of Safety and Efficacy of a Novel Minimally Invasive Lumbar Interspinous Fusion Device.

INTRODUCTION: Several treatment options exist for those with spinal stenosis, as well as degenerative changes. This series evaluates the use of an interspinous fixation (ISF) device as performed by interventional pain physicians. METHODS: This is a retrospective analysis identifying 32 patients with the diagnosis of lumbar degenerative disc disease with secondary diagnosis of lumbar spinal stenosis being treated with ISF with Aurora Spine Zip Interspinous Spacer. Serious adverse events, specifically nerve injury, hematoma, infection, and death, were analyzed quantitatively for reported complications within 90 days from the procedure. In addition, VAS was analyzed for patient reported outcomes. RESULTS: Adverse event rate was 0% with no incidences of reoperation, or device removal. Estimated blood loss was recorded as less than 50 cc for all patients. The preoperative pain assessment demonstrated an average pain score of 8.1 and a postoperative pain score of 2.65 equating to a percentage pain reduction of 67%. CONCLUSION: This case series demonstrates the success and safety of ISF being performed by interventional pain physicians in an outpatient setting. It is a valuable tool in the treatment of moderate to severe lumbar spinal stenosis and degenerative disc disease that has decreased morbidity and significant efficacy.

Advanced meta-analyses comparing the three surgical techniques total disc replacement, anterior stand-alone fusion and circumferential fusion regarding pain, function and complications up to 3 years to treat lumbar degenerative disc disease.

PURPOSE: The purpose of our meta-analyses is to find the most appropriate surgical technique treating lumbar degenerative disc disease (DDD). Spinal fusion is the conventional treatment for lumbar DDD. Total disc replacement (TDR) has been developed to avoid negative effects of fusions by preserving functionality. To our knowledge, there is no evaluation comparing meta-analytically the clinical results of three different surgical techniques with same inclusion and exclusion criteria for treating DDD. METHODS: The surgical techniques TDR, anterior lumbar interbody fusion (ALIF) and circumferential fusion (CFF) are pairwise meta-analytically compared. Primary outcomes are pain measured by the Visual Analogue Scale (VAS) and function measured by the Oswestry Disability Index (ODI). Secondary outcomes are the mean number of complications per case (MNOC) at surgery and follow-up and the overall MNOC. RESULTS: In our systematic search, we found finally six prospective studies with the minimum follow-up of two years: four randomized controlled trials and two cohort studies. In VAS and ODI, TDR is proved to be superior to ALIF and CCF (p < 0.05), whereat ALIF is more effective than CFF without statistical significance. CFF presents the best result in complications with the lowest overall MNOC (0.1), followed by TDR (1.2) and ALIF (1.5). CONCLUSION: According to our meta-analyses, we regard TDR to be the most appropriate surgical technique treating DDD, followed by ALIF. Further studies with a longer follow-up are needed using the same methodical approach to strengthen the VAS and ODI results and to explain the discrepant result to complications.

Accurate prediction of lumbar microdecompression level with an automated MRI grading system.

OBJECTIVE: Lumbar spine MRI interpretations have high variability reducing utility for surgical planning. This study evaluated a convolutional neural network (CNN) framework that generates automated MRI grading for its ability to predict the level that was surgically decompressed. MATERIALS AND METHODS: Patients who had single-level decompression were retrospectively evaluated. Sagittal T2 images were processed by a CNN (SpineNet), which provided grading for the following: central canal stenosis, disc narrowing, disc degeneration, spondylolisthesis, upper/lower endplate morphologic changes, and upper/lower marrow changes. The grades were used to calculate an aggregate score. The variables and the aggregate score were analyzed for their ability to predict the surgical level. For each surgical level subgroup, the surgical level aggregate scores were compared with the non-surgical levels. RESULTS: A total of 141 patients met the inclusion criteria (82 women, 59 men; mean age 64 years; age range 28-89 years). SpineNet did not identify central canal stenosis in 32 patients. Of the remaining 109, 96 (88%) patients had a decompression at the level of greatest stenosis. The higher stenotic grade was present only at the surgical level in 82/96 (85%) patients. The level with the highest aggregate score matched the surgical level in 103/141 (73%) patients and was unique to the surgical level in 91/103 (88%) patients. Overall, the highest aggregate score identified the surgical level in 91/141 (65%) patients. The aggregate MRI score mean was significantly higher for the L3-S1 surgical levels. CONCLUSION: A previously developed CNN framework accurately predicts the level of microdecompression for degenerative spinal stenosis in most patients.

Effect of postural changes on in vivo pelvic tilt and functional component anteversion in total hip arthroplasty patients with lumbar disc degenerations.

AIMS: The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. METHODS: A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system. RESULTS: PT, FCA, ΔPT, and ΔFCA were significantly correlated with the severity of lumbar DDD. Patients with severe lumbar DDD showed marked differences in PT with changes in posture; there was an anterior tilt (-16.6° vs -12.3°, p = 0.047) in the supine position, but a posterior tilt in an upright posture (1.0° vs -3.6°, p = 0.005). A significant decrease in ΔFCA during stand-to-swing (8.6° vs 12.8°, p = 0.038) and stand-to-stance (7.3° vs 10.6°,p = 0.042) was observed in the severe lumbar DDD group. CONCLUSION: There were marked differences in the relationship between PT and posture in patients with severe lumbar DDD compared with healthy controls. Clinical decision-making should consider the relationship between PT and FCA in order to reduce the risk of impingement at large ranges of motion in THA patients with lumbar DDD. Cite this article: Bone Joint J 2020;102-B(11):1505-1510.

Effect of postural changes on in vivo pelvic tilt and functional component anteversion in total hip arthroplasty patients with lumbar disc degenerations.

AIMS: The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. METHODS: A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system. RESULTS: PT, FCA, ΔPT, and ΔFCA were significantly correlated with the severity of lumbar DDD. Patients with severe lumbar DDD showed marked differences in PT with changes in posture; there was an anterior tilt (-16.6° vs -12.3°, p = 0.047) in the supine position, but a posterior tilt in an upright posture (1.0° vs -3.6°, p = 0.005). A significant decrease in ΔFCA during stand-to-swing (8.6° vs 12.8°, p = 0.038) and stand-to-stance (7.3° vs 10.6°,p = 0.042) was observed in the severe lumbar DDD group. CONCLUSION: There were marked differences in the relationship between PT and posture in patients with severe lumbar DDD compared with healthy controls. Clinical decision-making should consider the relationship between PT and FCA in order to reduce the risk of impingement at large ranges of motion in THA patients with lumbar DDD.

Longitudinal smartphone-based self-assessment of objective functional impairment in patients undergoing surgery for lumbar degenerative disc disease: initial experience.

BACKGROUND: The worldwide spread of smartphone usage enables new possibilities for longitudinal monitoring of objective functional impairment (OFI) in patients undergoing surgery for lumbar degenerative disc disease (DDD). METHODS: Three patients, undergoing elective surgery for lumbar DDD, self-assessed OFI using a recently validated 6-min walking test (6WT) smartphone application. Results are presented as raw 6-min walking distance (6WD) as well as in reference to age- and sex-specific healthy population reference values using standardized z-scores (number of standard deviations). In parallel, patient-reported outcome measures (PROMs), including numeric rating scale (NRS) leg-pain and Core Outcome Measures Index (COMI) were obtained before (pre) and 6 weeks (6 W) as well as 3 months (3 M) after surgery. Descriptive analyses were used to compare PROMs with repeated 6WT measurements over time. The feasibility and benefits of the longitudinal OFI measurements using the 6WT app are discussed. RESULTS: One patient presented a favorable outcome, reflected by a clinically meaningful improvement in PROMs. Correspondingly, the 6WT distance gradually improved above the normal population values ((pre 399 m (z-score - 1.96) vs. 6 W 494 m (- 0.85) vs. 3 M 557 m (- 0.1)). One patient experienced initial improvement at 6 W, followed by a decline in 6WD at 3 M which promoted further interventions with subsequent recovery ((358 m (z-score - 3.29) vs 440 m (- 2.2) vs 431 m (- 2.32) vs 471 m (- 1.78)). The last patient showed a lack of improvement in PROMs as well as in OFI (360 m (z-score 0.0) vs 401 m (0.30) vs 345 m (- 0.11)) resulting in secondary surgery. CONCLUSION: The longitudinal assessment of OFI using the 6WT app was feasible and provided the physician with a detailed history of patients' postoperative walking capacity complementing commonly used PROMs.

Mineralized collagen-modified PMMA cement enhances bone integration and reduces fibrous encapsulation in the treatment of lumbar degenerative disc disease.

As a minimally invasive surgery, percutaneous cement discoplasty (PCD) is now contemplated to treat lumbar disc degeneration disease in elder population. Here, we investigated whether the osteogenic mineralized collagen (MC) modified polymethylmethacrylate (PMMA) cement could be a suitable material in PCD surgery. Injectability, hydrophilicity and mechanical properties of the MC-modified PMMA (PMMA-MC) was characterized. The introduction of MC did not change the application and setting time of PMMA and was easy to be handled in minimally invasive operation. Hydrophilicity of PMMA-MC was greatly improved and its elastic modulus was tailored to complement mechanical performance of bone under dynamic stress. Then, PCD surgery in a goat model with induced disc degeneration was performed with implantation of PMMA-MC or PMMA. Three months after implantation, micro-computed tomography analysis revealed a 36.4% higher circumferential contact index between PMMA-MC and bone, as compared to PMMA alone. Histological staining confirmed that the surface of PMMA-MC was in direct contact with new bone, while the PMMA was covered by fibrous tissue. The observed gathering of macrophages around the implant was suspected to be the cause of fibrous encapsulation. Therefore, the interactions of PMMA and PMMA-MC with macrophages were investigated in vitro. We discovered that the addition of MC could hinder the proliferation and fusion of the macrophages. Moreover, expressions of fibroblast-stimulating growth factors, insulin-like growth factor, basic fibroblast growth factor and tumor necrosis factor-ß were significantly down-regulated in the macrophages cocultured with PMMA-MC. Together, the promoted osteointegration and reduced fibrous tissue formation observed with PMMA-MC material makes it a promising candidate for PCD surgery.

Lower Extremity Motor Deficits Are Underappreciated in Patient-Reported Outcome Measures: Added Value of Objective Outcome Measures.

OBJECTIVE: The patient-reported outcome measure (PROM)-based evaluation in lumbar degenerative disc disease (DDD) is today's gold standard but has limitations. We studied the impact of lower extremity motor deficits (LEMDs) on PROMs and a new objective outcome measure. METHODS: We evaluated patients with lumbar DDD from a prospective 2-center database. LEMDs were graded according to the British Medical Research Council (BMRC; 5 [normal] -0 [no movement]). The PROM-based evaluation included pain (visual analogue scale), disability (Oswestry Disability Index [ODI] & Roland-Morris Disability Index [RMDI]), and health-related quality of life (HRQoL; Short-Form 12 physical component summary/mental component summary & EuroQol-5D index). Objective functional impairment (OFI) was determined as age- and sex-adjusted Timed-Up and Go (TUG) test value. RESULTS: One hundred five of 375 patients (28.0%) had a LEMD. Patients with LEMD had slightly higher disability (ODI: 52.8 vs. 48.2, p = 0.025; RMDI: 12.6 vs. 11.3, p = 0.034) but similar pain and HRQoL scores. OFI T-scores were significantly higher in patients with LEMD (144.2 vs. 124.3, p = 0.006). When comparing patients with high- (BMRC 0-2) vs. low-grade LEMD (BMRC 3-4), no difference was evident for the PROM-based evaluation (all p > 0.05) but patients with high-grade LEMD had markedly higher OFI T-scores (280.9 vs. 136.0, p = 0.001). Patients with LEMD had longer TUG test times and OFI T-scores than matched controls without LEMDs. CONCLUSION: Our data suggest that PROMs fail to sufficiently account for LEMD-associated disability, which is common and oftentimes bothersome to patients. The objective functional evaluation with the TUG test appears to be more sensitive to LEMD-associated disability. An objective functional evaluation of patients with LEMD appears reasonable.