Lumbar spine fusion for chronic low back pain due to degenerative disc disease: a systematic review

Degenerative lumbar spondylolisthesis: review of current classifications and proposal of a novel classification system

PURPOSE

To review existing classification systems for degenerative spondylolisthesis (DS), propose a novel classification designed to better address clinically relevant radiographic and clinical features of disease, and determine the inter- and intraobserver reliability of this new system for classifying DS.

METHODS

The proposed classification system includes four components: 1) segmental dynamic instability, 2) location of spinal stenosis, 3) sagittal alignment, and 4) primary clinical presentation. To establish the reliability of this system, 12 observers graded 10 premarked test cases twice each. Kappa values were calculated to assess the inter- and intraobserver reliability for each of the four components separately.

RESULTS

Interobserver reliability for dynamic instability, location of stenosis, sagittal alignment, and clinical presentation was 0.94, 0.80, 0.87, and 1.00, respectively. Intraobserver reliability for dynamic instability, location of stenosis, sagittal alignment, and clinical presentation were 0.91, 0.88, 0.87, and 0.97, respectively.

CONCLUSION

The UCSF DS classification system provides a novel framework for assessing DS based on radiographic and clinical parameters with established implications for surgical treatment. The almost perfect interobserver and intraobserver reliability observed for all components of this system demonstrates that it is simple and easy to use. In clinical practice, this classification may allow subclassification of similar patients into groups that may benefit from distinct treatment strategies, leading to the development of algorithms to help guide selection of an optimal surgical approach. Future work will focus on the clinical validation of this system, with the goal of providing for more evidence-based, standardized approaches to treatment and improved outcomes for patients with DS.

Safety and benefit of ambulation within 24 hours in elderly patients undergoing lumbar fusion: propensity score matching study of 882 patients

BACKGROUND CONTEXT

Elderly patients are less likely to recover from lumbar spine fusion (LSF) as rapidly compared with younger patients. However, there is still a lack of research on the effect of early ambulation on elderly patients undergoing LSF surgery for lumbar degenerative disorders.

PURPOSE

To evaluate the safety and benefit of ambulation within 24 hours in elderly patients who underwent LSF.

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

Consecutive patients (aged 65 and older) who underwent elective transforaminal lumbar interbody fusion surgery for degenerative disorders from January 2019 to October 2022.

OUTCOME MEASURES

Outcome measures included postoperative complications, postoperative drainage (mL), laboratory test data, length of hospital stay (LOS), readmission and reoperation within 3 months.

METHODS

Early ambulation patients (ambulation within 24 hours after surgery) were propensity-score matched 1:1 to a delayed ambulation patients (ambulation at a minimum of 48 hours postoperatively) based on age, intraoperative blood loss, and number of fused segments. The incidence of postoperative adverse events (AEs, including rates of complications, readmission, and prolonged LOS) and the average LOS were used to assess the safety and benefit of early ambulation, respectively. Multivariable regression analysis was performed to assess the association between early ambulation and postoperative AEs. The risk factors for delayed ambulation were also determined using multivariable logistic analyses.

RESULTS

A total of 998 patients with LSF surgery were reviewed in this study. After excluding 116 patients for various reasons, 882 patients (<24 hours: N=350, 24-48 hours: N=230, and >48 hours: N= 302) were included in the final analysis. After matching, sex, BMI, preoperative comorbidities, laboratory test data and surgery-related variables were comparable between the groups. The incidence of postoperative AEs was significantly lower in the EA group (44.3% vs 64.0%, p<.001). The average postoperative LOS of the EA group was 2 days shorter than the DA group (6.5 days vs 8.5 days, p<.001). Patients in the EA group had a significantly lower rate of prolonged LOS compared with the DA group (35.1% vs 55.3%, p<.001). There was no significant difference in postoperative drainage volumes between the two groups. Multivariable analysis identified older age (odds ratio [OR] 1.07, p<.001), increased intraoperative EBL (OR 1.002, p=.001), and higher international normalization ratio (OR 10.57, p=.032) as significant independent risk factors for delayed ambulation.

CONCLUSIONS

Ambulation within 24 hours after LSF surgery is independently associated fewer AEs and shorter hospital stays in elderly patients. Implementing the goal of ambulation within 24 hours after LSF surgery into enhanced recovery after surgery protocols for elderly patients seems appropriate. Older age, increased intraoperative blood loss and worse coagulation function are associated with delayed ambulation.

Exosome-mediated Repair of Intervertebral Disc Degeneration: The Potential Role of miRNAs

Intervertebral disc degeneration (IVDD) is a serious condition that manifests as low back pain, intervertebral disc protrusion, and spinal canal stenosis. At present, the main treatment methods for IVDD are surgical interventions such as discectomy, total disc replacement, and spinal fusion. However, these interventions have shown limitations, such as recurrent lumbar disc herniation after discectomy, lesions in adjacent segments, and failure of fixation. To overcome these shortcomings, researchers have been exploring stem cell transplantation therapy, such as mesenchymal stem cell (MSC) transplantation, but the treatment results are still controversial. Therefore, researchers are in search of new methods that are more efficient and have better outcomes. The exosomes from stem cells contain a variety of bioactive molecules that mediate cell interactions, and these components have been investigated for their potential therapeutic role in the repair of various tissue injuries. Recent studies have shown that MSC-derived miRNAs in exosomes and vesicles have therapeutic effects on nucleus pulposus cells, annulus fibrosus, and cartilage endplate. miRNAs play a role in many cell activities, such as cell proliferation, apoptosis, and cytokine release, by acting on mRNA translation, and they may have immense therapeutic potential, especially when combined with stem cell therapy. This article reviews the current status of research on intervertebral disc repair, especially with regard to the latest research findings on the molecular biological mechanisms of miRNAs in MSC-derived exosomes in intervertebral disc repair.

Management Considerations for Total Intervertebral Disc Replacement

The burden of disease regarding lumbar and cervical spine pain is a long-standing, pervasive problem within medicine that has yet to be resolved. Specifically, neck and back pain are associated with chronic pain, disability, and exorbitant health care use worldwide, which have only been exacerbated by the increase in overall life years and chronic disease. Traditionally, patients with significant pain and disability secondary to disease of either the cervical or lumbar spine are treated via fusion or discectomy. Although these interventions have proved curative in the short-term, numerous longitudinal studies evaluating the efficacy of traditional management have reported severe impairment of normal spinal range of motion, as well as postoperative complications, including neurologic injury, radiculopathy, osteolysis, subsidence, and infection, paired with less than desirable reoperation rates. Consequently, there is a call for innovation and improvement in the treatment of lumbar and cervical spine pain, which may be answered by a modern technique known as intervertebral disc arthroplasty, or total disc replacement (TDR). Thus, this review aims to describe the management strategy of TDR and to explore updated considerations for its use in practice, both to help guide clinical decision making.

A Decreasing National Trend in Lumbar Disc Arthroplasty

STUDY DESIGN

Retrospective National Database Study.

OBJECTIVES

The aim of this study was to investigate the national trend of lumbar disc arthroplasty (LDA) utilization from 2005 to 2017.

METHODS

Patients undergoing primary LDA between 2005 and 2017 were identified in the National Inpatient Sample (NIS) database. Year of the procedure, demographic, socioeconomic, hospital, and cost parameters were analyzed. The data was weighted using provided weights from the NIS database to generate national estimates of LDA procedure incidence. Lastly, we assessed the incidence of cervical disc arthroplasty (CDA) between 2005 and 2017 to serve as a historical comparison.

RESULTS

An estimated 20 460 patients underwent primary LDA in the United States between 2005 and 2017. There was an initial decrease in LDA procedures between 2005 and 2006 and then a plateau between 2006 and 2009. From 2010 to 2013, there was a significant year-over-year decrease in annual LDA procedures performed, followed by a second plateau from 2014 to 2017. Overall, LDA procedures decreased 82% from 2005 to 2017. Over the same time, the annual incidence of CDA utilization increased 795% from approximately 474 procedures in 2005 to 4245 procedures in 2017 (P < .01).

CONCLUSIONS

Lumbar disc arthroplasty utilization decreased 82% from 2005 to 2017, with a significant decrease in the rate of utilization noted after 2010. The utilization of LDA to treat selected degenerative lumbar conditions has not paralleled the increasing popularity of CDA, and, in fact, has demonstrated a nearly opposite utilization trend.

Umbilical cord mesenchymal stem cells for regenerative treatment of intervertebral disc degeneration

Intervertebral disc degeneration is thought to be a major contributor to low back pain, the etiology of which is complex and not yet fully understood. To compensate for the lack of drug and surgical treatment, mesenchymal stem cells have been proposed for regenerative treatment of intervertebral discs in recent years, and encouraging results have been achieved in related trials. Mesenchymal stem cells can be derived from different parts of the body, among which mesenchymal stem cells isolated from the fetal umbilical cord have excellent performance in terms of difficulty of acquisition, differentiation potential, immunogenicity and ethical risk. This makes it possible for umbilical cord derived mesenchymal stem cells to replace the most widely used bone marrow-derived and adipose tissue derived mesenchymal stem cells as the first choice for regenerating intervertebral discs. However, the survival of umbilical cord mesenchymal stem cells within the intervertebral disc is a major factor affecting their regenerative capacity. In recent years biomaterial scaffolds in tissue engineering have aided the survival of umbilical cord mesenchymal stem cells by mimicking the natural extracellular matrix. This seems to provide a new idea for the application of umbilical cord mesenchymal stem cells. This article reviews the structure of the intervertebral disc, disc degeneration, and the strengths and weaknesses of common treatment methods. We focus on the cell source, cell characteristics, mechanism of action and related experiments to summarize the umbilical cord mesenchymal stem cells and explore the feasibility of tissue engineering technology of umbilical cord mesenchymal stem cells. Hoping to provide new ideas for the treatment of disc degeneration.

Outcomes of patients undergoing single-level arthroplasty versus anterior lumbar interbody fusion

BACKGROUND

Compared to vertebral body fusion, artificial discs are thought to lessen the risks of adjacent segment disease and the need for additional surgery by maintaining spinal mobility as they mimic the intervertebral disc structure. No studies have compared the rates of postoperative complications and the requirement for secondary surgery at adjacent segments among patients who have undergone anterior lumbar interbody fusions (ALIF) versus those undergoing lumbar arthroplasty.

METHODS

An all-payer claims database identified 11,367 individuals who underwent single-level ALIF and lumbar arthroplasty for degenerative disc disease (DDD) between January 2010 and October 2020. Rates of complications following surgery, the need for additional lumbar surgeries, length of stay (LOS), and postoperative opioid utilization were assessed in matched cohorts based on logistic regression models. Kaplan-Meyer plots were created to model the probability of additional surgery.

RESULTS

Following 1:1 exact matching, 846 records of patients who had undergone ALIF or lumbar arthroplasty were analyzed. All-cause readmission within 30-30 days following surgery was significantly higher in patients undergoing ALIF versus arthroplasty (2.6% vs. 0.71%, p = 0.02). LOS was significantly lower among the patients who had undergone ALIF (1.043 ± 0.21 vs. 2.17 ± 1.7, p < .001).

CONCLUSIONS

ALIF and lumbar arthroplasty procedures are equally safe and effective in treating DDD. Our findings do not support that single-level fusions may biomechanically necessitate revisional surgeries.

Preoperative community based functional high intensity interval training (f-HIIT) with high-risk patients opting for lumbar spinal fusion: a pilot study

PURPOSE

To determine the feasibility, safety and preliminary effectiveness of preoperative functional high-intensity interval training (f-HIIT) for high-risk patients undergoing LSF.

MATERIALS AND METHODS

High-risk patients eligible for elective 1-3 level LSF were included. Feasibility and safety of the preoperative f-HIIT program was determined by measuring participation and attrition rates, training adherence, adverse events, reached training intensity and preoperative progression in physical fitness. Preliminary effect of the preoperative f-HIIT program was estimated on time to postoperative functional recovery and length of hospital stay (LoS) between high-risk patients who did and did not participate in the prehabilitation program.

RESULTS

Eleven out of 23 high-risk patients opted to participate in the f-HIIT program, which was safe and feasible, as no adverse events occurred and only one out of 74 sessions was missed (1.4%). Trained high-risk patients improved their physical fitness with 21.2% on average and obtained faster time to functional recovery compared to matched untrained patients (median 4.5 vs 7.5 days; p = 0.013). No effect was seen on LoS (median 7 vs 8 days (p = 0.58)).

CONCLUSIONS

The preoperative f-HIIT program is feasible, safe and shortened time to postoperative functional recovery in patients who underwent LSF.Implications for rehabilitationPreoperative high-intensity interval training is safe and feasible for high-risk patients opting for lumbar spinal fusion.In a relatively small sample the study shows preoperative high-intensity interval training could reduce time to functional recovery in high-risk patients opting for lumbar spinal fusion.

Evaluating Screw Stability After Pedicle Screw Fixation With PEEK Rods

STUDY DESIGN

Animal experiment.

OBJECTIVE

To evaluate whether the use of polyetheretherketone (PEEK) rods for posterior spinal fixation can improve screw stability.

METHODS

Sheep models of anterior-posterior cervical fusion were used in this study. Six sheep were randomly assigned to the PEEK rod group and titanium alloy group. A total of 8 screws and 2 fixing rods were implanted in each sheep. At 24 weeks postoperatively, a computed tomography (CT) evaluation, pull-out test, micro-CT evaluation and histological evaluation were conducted to evaluate screw stability in the harvested surgical segments.

RESULT

According to the CT evaluation, there were no signs of screw loosening in either group. The pull-out force and energy of the PEEK rod group were significantly higher than those of the titanium alloy rod group. Denser and thicker trabecular bone around the screw was observed in the PEEK rod group according to the micro-CT reconstructed images, and quantitative analysis of the micro-CT data confirmed this finding. In the histological evaluation, more abundant and denser bone trabeculae were also observed in the PEEK rod group. However, there was no significant difference in the bone-screw interface between the 2 groups.

CONCLUSION

Posterior spinal fixation with PEEK rods can increase screw stability by promoting bone growth around the screw but cannot promote bone integration at the bone-screw interface in an animal model study. This finding presents a new idea for clinical practices to reduce screw loosening rate.

The Divergence Between Hospital Charges and Reimbursements For Primary 1-2-level Lumbar Fusion Has Increased Over Time: A Medicare Administrative Claims Analysis

STUDY DESIGN

A retrospective cohort study was performed for patients undergoing 1-2-level lumbar fusion (1-2LF) from 2005 to 2014 using an administrative claims database.

OBJECTIVE

The objective of this study was to determine changes in: (1) annual charges; (2) annual reimbursement rates; and (3) annual difference (charges minus reimbursements) in patients undergoing 1-2LF.

SUMMARY OF BACKGROUND DATA

With implementation of value-based care in orthopaedics, coupled with the rise in number of patients undergoing 1-2LF, understanding the discordance in hospital charges and reimbursements is needed. The difference in hospital charges to reimbursements specifically for 1-2LF for degenerative disc disease has not been studied.

MATERIALS AND METHODS

A Medicare administrative claims database was queried for patients undergoing primary lumbar fusion using ICD-9 procedural code 81.04-81.08. Patients specifically undergoing 1-2LF were filtered from this cohort using ICD-9 procedural code 81.62. The query yielded 547,067 patients who underwent primary 1-2LF. Primary outcomes analyzed included trends in charges, reimbursement rates, and net difference in cost over time and per annual basis. Linear regression evaluated the change in costs over time with a P -value less than 0.05 considered significant.

RESULTS

From 2005 to 2014, total charges increased from $6,085,838,407 to $19,621,979,956 and total reimbursements increased from $1,677,764,831 to $4,656,702,685 (all P <0.001). Per patient charges increased 92.10% from 2005 to 2014 for patients undergoing primary 1-2LF from $129,992 to $249,697 ( P <0.001). Similarly, an increase in reimbursement per patient of 65.35% from $35,836 to $59,258 ( P <0.001) was noted. The annual difference in charges to reimbursements increased 102.26% during the study interval from $94,155 to $190,439 ( P <0.001).

CONCLUSIONS

Per patient charges and reimbursements both increased over the study period; however, charges increased 30% more than reimbursements. Further breakdown of hospital, surgeon, and anesthesiologist reimbursements for 1-2LF is needed.

LEVEL OF EVIDENCE

Level III.

Additional operation rates after surgery for degenerative spine diseases: minimum 10 years follow-up of 4705 patients in the national Swedish spine register

OBJECTIVES

To identify rates of additional operation after the index operation for degenerative lumbar spine diseases.

DESIGN

Retrospective register study.

SETTING

National outcome data from Swespine, the National Swedish spine register.

PARTICIPANTS

A total of 4705 patients who underwent one-level surgery for degenerative disk disease (DDD) or lumbar spinal stenosis (LSS) with or without degenerative spondylolisthesis (DS) between 1 January 2007 and 31 December 2010 were followed from 1 January 2007 to 31 December 2020 to record all cases of additional lumbar spine operations.

INTERVENTIONS

One-level spinal decompression and/or posterolateral fusion for degenerative spine diseases.

PRIMARY OUTCOME MEASURES

Number of additional operations.

RESULTS

Additional operations were more common at adjacent levels for patients with LSS with DS treated with decompression and fusion whereas additional operations were more evenly distributed between the index level and the adjacent levels for DDD treated with fusion and LSS with and without DS treated with decompression only. For patients younger than 60 years, treated with decompression and fusion for LSS with DS, the additional operations were evenly distributed between the index level and the adjacent levels.

CONCLUSIONS

There are different patterns of additional operations following the index procedure after surgery for degenerative spine diseases. Rigidity across previously mobile segments is not the only important factor in the development of adjacent segment disease (ASD) after spinal fusion, also the underlying disease and age may play parts in ASD development. The findings of this study can be used in the shared decision-making process when surgery is a treatment option for patients with degenerative lumbar spine diseases as the first operation may be the start of a series of additional spinal operations for other degenerative spinal conditions, either at the index level or at other spinal levels.

Emerging polymeric material strategies for cartilage repair

Cartilage is found throughout the body, serving an array of essential functions. Owing to the limited healing capacity of cartilage, damage or degeneration is often permanent and so requires clinical intervention. Established surgical techniques generally rely on biological grafting. However, recent advances in polymeric materials provide an encouraging alternative to overcome limits of auto- and allografts. For regenerative engineering of cartilage, a polymeric scaffold ideally supports and instructs tissue regeneration while also providing mechanical integrity. Scaffolds direct regeneration via chemical and mechanical cues, as well as delivery and support of exogenous cells and bioactive factors. Advanced polymeric scaffolds aim to direct regeneration locally, replicating the heterogeneities of native tissues. Alternatively, new cartilage-mimetic hydrogels have potential to serve as synthetic cartilage replacements. Prepared as multi-network or composite hydrogels, the most promising candidates have simultaneously realized the hydration, mechanical, and tribological properties of native cartilage. Collectively, the recent rise in polymers for cartilage regeneration and replacement proposes a changing paradigm, with a new generation of materials paving the way for improved clinical outcomes.

The Effect of the Severity of Preoperative Leg Pain on Patient-Reported Outcomes, Minimum Clinically Important Difference Achievement, and Patient Satisfaction After Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcome measures (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients stratified by preoperative leg pain.

METHODS

Patients undergoing MIS-TLIF were collected through retrospective review of a prospectively maintained single-surgeon database. PROMs administered preoperatively/postoperatively included Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), visual analog scale (VAS) back/leg pain, Oswestry Disability Index (ODI), and 12-Item Short Form (SF-12) Physical/Mental Component Score (PCS/MCS). Patients were grouped based on preoperative VAS leg scores: VAS leg ≤7 or VAS leg >7. Inferential statistics were used to compare PROMs, MCID achievement rates, and postoperative satisfaction between groups.

RESULTS

A total of 562 patients were eligible (168 VAS leg score ≤7; 394 VAS leg score >7). Significant differences between cohorts in postoperative mean PROMs were noted for PROMIS-PF at 6 weeks/2 years, SF-12 PCS at 6 weeks/2 years, SF-12 MCS at 6 weeks/12 weeks/6 months/1 year, VAS back score at 6 weeks/12 weeks/6 months, VAS leg score at 6 weeks/12 weeks/6 months/2 years and ODI at all postoperative time points (P < 0.045, all). In the VAS leg score >7 cohort, a greater proportion achieving MCID for VAS leg score at all postoperative time points and ODI at 12 weeks (P < 0.010, all). Postoperative satisfaction was greater in VAS back score ≤7 cohort for VAS leg score at 6 weeks/12 weeks/6 months/2 years, VAS back score at 12 weeks/2 years, and ODI at 6 weeks/12 weeks/6 months/2 years (P < 0.046, all).

CONCLUSIONS

Patients with severe preoperative leg pain showed worse postoperative PROM scores and patient satisfaction for disability and back/leg pain. MCID achievement rates across cohorts were similar. Patients with severe leg pain may have expectations for surgical benefits incongruent with their postoperative outcomes, and physicians may seek to manage the preoperative expectations of their patients to reflect likely outcomes after MIS-TLIF.

Biomechanical evaluation of a novel repair strategy for intervertebral disc herniation in an ovine lumbar spine model

Following herniation of the intervertebral disc, there is a need for advanced surgical strategies to protect the diseased tissue from further herniation and to minimize further degeneration. Accordingly, a novel tissue engineered implant for annulus fibrosus (AF) repair was fabricated via three-dimensional fiber deposition and evaluated in a large animal model. Specifically, lumbar spine kinetics were assessed for eight (n = 8) cadaveric ovine lumbar spines in three pure moment loading settings (flexion-extension, lateral bending, and axial rotation) and three clinical conditions (intact, with a defect in the AF, and with the defect treated using the AF repair implant). In ex vivo testing, seven of the fifteen evaluated biomechanical measures were significantly altered by the defect. In each of these cases, the treated spine more closely approximated the intact biomechanics and four of these cases were also significantly different to the defect. The same spinal kinetics were also assessed in a preliminary in vivo study of three (n = 3) ovine lumbar spines 12 weeks post-implantation. Similar to the ex vivo results, functional efficacy of the treatment was demonstrated as compared to the defect model at 12 weeks post-implantation. These promising results motivate a future large animal study cohort which will establish statistical power of these results further elucidate the observed outcomes, and provide a platform for clinical translation of this novel AF repair patch strategy. Ultimately, the developed approach to AF repair holds the potential to maintain the long-term biomechanical function of the spine and prevent symptomatic re-herniation.

Motion of Lumbar Endplate in Degenerative Lumbar Scoliosis Patients with Different Cobb Angle In Vivo: Reflecting the Biomechanics of the Lumbar Disc

Study Design. Controlled laboratory study. Objective. To evaluate the influence of degenerative lumbar scoliosis (DLS) with different Cobb angles and degenerative discs on the range of motion (ROM) of the lumbar endplates during functional weight-bearing activities in vivo. Summary of Background. DLS data might influence spinal stability and range of motion of the spine. Altered lumbar segment motion is thought to be related to disc degeneration. However, to date, no data have been reported on the motion patterns of the lumbar endplates in patients with DLS in vivo. Methods. We recorded 42 DLS patients with the apical disc at L2-L3 and L3-L4. Patients were divided into A group with a coronal Cobb angle >20° (number: 13; $62.00\pm 8.57$ years old) and group B with a coronal Cobb angle <20° (number: 28; $65.79\pm 6.66$ years old). Patients’ discs were divided into a degenerated disc group (III-V) and a nondegenerated disc group (I-II) according to the Pfirrmann classification. Computed tomography (CT) was performed on every subject to build 3-dimensional (3D) models of the lumbar vertebrae (L1–S1), and then the vertebras were matched according to the dual fluoroscopic imaging system. The kinematics of the endplate was compared between the different Cobb angle groups and the healthy group reported in a previous study and between the degenerative disc group and nondegenerative disc group by multiway analysis of variance. Results. Coupled translation at L5-S1 was higher than other levels during the three movements. During the flexion-extension of the trunk, around the anteroposterior axis, rotation in group A was higher than that in the control group at L2-L3 and L3-L4 ( $6.62\pm 3.61$  mm vs $4.36\pm 2.55$  mm, $5.01\pm 3.19$  mm; $P<0.05$ , $P<0.05$ ). During the left-right bending of the trunk, around the mediolateral axis, rotations in groups A and B were higher than those in the control group at L5-S1 ( $17.52\pm 11.43$ °, $17.25\pm 9.22$ ° vs $10.08\pm 5.42$ °; $P<0.05$ , $P<0.05$ ). During the left-right torsion, around the anteroposterior axis, rotation in group A was higher than that in group B and the control group at L2-3 ( $9.69\pm 5.94$ ° vs $5.77\pm 4.02$ °, $4.47\pm 2.00$ °; $P<0.05$ , $P<0.05$ ). In patients with Cobb angle <20°, coupled translation was higher in the degenerated disc group than in the nondegenerated disc group, especially along the anteroposterior axis. Conclusion. An increase in the coupled rotation of the endplate at the scoliotic apical level in patients with DLS was related to a larger Cobb angle. Moreover, segments with degenerative discs had higher coupled translations in the anteroposterior direction than segments with nondegenerative discs in DLS patients with Cobb angle <20°. These data might provide clues regarding the etiology of DLS and the basis for operative planning.

An ex-vivo model for the biomechanical assessment of cement discoplasty

Percutaneous Cement Discoplasty (PCD) is a surgical technique developed to relieve pain in patients with advanced degenerative disc disease characterized by a vacuum phenomenon. It has been hypothesized that injecting bone cement into the disc improves the overall stability of the spinal segment. However, there is limited knowledge on the biomechanics of the spine postoperatively and a lack of models to assess the effect of PCD ex-vivo. This study aimed to develop a biomechanical model to study PCD in a repeatable and clinically relevant manner. Eleven ovine functional spinal units were dissected and tested under compression in three conditions: healthy, injured and treated. Injury was induced by a papain buffer and the treatment was conducted using PMMA cement. Each sample was scanned with micro-computed tomography (CT) and segmented for the three conditions. Similar cement volumes (in %) were injected in the ovine samples compared to volumes measured on clinical PCD CT images. Anterior and posterior disc heights decreased on average by 22.5% and 23.9% after injury. After treatment, the anterior and posterior disc height was restored on average to 98.5% and 83.6%, respectively, of their original healthy height. Compression testing showed a similar stiffness behavior between samples in the same group. A decrease of 51.5% in segment stiffness was found after injury, as expected. The following PCD treatment was found to result in a restoration of stiffness—showing only a difference of 5% in comparison to the uninjured state. The developed ex-vivo model gave an adequate representation of the clinical vacuum phenomena in terms of volume, and a repeatable mechanical response between samples. Discoplasty treatment was found to give a restoration in stiffness after injury. The data presented confirm the effectiveness of the PCD procedure in terms of restoration of axial stiffness in the spinal segment. The model can be used in the future to test more complex loading scenarios, novel materials, and different surgical techniques.

Impact of Patient-specific Factors and Spinopelvic Alignment on the Development of Adjacent Segment Degeneration After Short-segment Lumbar Fusion

STUDY DESIGN

Prospective cross-sectional cohort study.

OBJECTIVES

The main purpose of this study was to evaluate the association between demographical, surgery-related and morphologic parameters, and the development or progress of adjacent segment degeneration (ASD) after short-segment lumbar fusions.

SUMMARY OF BACKGROUND DATA

ASD is a major long-term complication after lumbar fusions. Possible risk factors are related to the patients' demographics, spinopelvic anatomy, or preoperative lumbar intervertebral disk conditions, but the role of these parameters is still not clear.

METHODS

A prospective cross-sectional study of 100 patients who underwent 1- or 2-level open lumbar transforaminal interbody fusions due to a lumbar degenerative pathology was conducted. Demographical, radiologic findings, and magnetic resonance imaging features were analyzed to identify factors associated with ASD in 5-year follow-up.

RESULTS

ASD patients showed higher level of pain ( P =0.004) and disability ( P =0.020) at follow-up. In univariate analysis, older age ( P =0.007), upper-level lumbar fusion ( P =0.007), lower L4-S1 lordosis ( P =0.039), pelvic incidence-lumbar lordosis mismatch ( P =0.021), Pfirrmann grade III or higher disk degeneration ( P =0.002), and the presence of disk bulge/protrusion ( P =0.007) were associated with ASD. In multivariate analysis, the presence of major degenerative sign (disk degeneration and/or disk bulge) was the significant predictor for developing ASD (odds ratio: 3.85, P =0.006).

CONCLUSION

By examining the role of different patient- and procedure-specific factors, we found that preoperative major degenerative signs at the adjacent segment increase the risk of ASD causing significantly worse outcome after short-segment lumbar fusion. On the basis of our results, adjacent disk conditions should be considered carefully during surgical planning.

Exploring clinically relevant risk profiles in patients undergoing lumbar spinal fusion: a cohort study

Purpose

To explore risk profiles of patients scheduled for lumbar spinal fusion (LSF) and their association with short-term recovery of patient after surgery.

Methods

Forty-nine patients scheduled for elective 1–3 level LSF between March 2019 and June 2020 were included. Patients underwent a preoperative risk screening, consisting of an anamnesis, questionnaires and physical performance tests. A latent profile analysis (LPA) was used to identify possible risk profiles within this population.

Results

Two risk profiles could be established: a fit and deconditioned risk profile. A significant between-profile difference was found in smoking status (p = 0.007), RAND36-PCS (p < 0.001), Timed Up and Go (TUG) (p < 0.001), de Morton Morbidity Index (DEMMI) (p < 0.001), finger floor distance (p = 0.050), motor control (p = 0.020) and steep ramp test (p = 0.005). Moreover, the fit risk profile had a significant shorter time to functional recovery (3.65 days versus 4.89 days, p = 0.013) and length of hospital stay (5.06 days versus 6.00 days, p = 0.008) compared to the deconditioned risk profile. No differences in complication rates between both risk profiles could be established. Allocation to a risk profile was associated with the functional recovery rate (p = 0.042), but not with LOS or complications.

Conclusion

This study found a fit and deconditioned risk profile. The patients with a fit risk profile perceived a better quality of life, performed better in mobility, motor control, cardiopulmonary tests and showed also a significant shorter stay in the hospital and a shorter time to functional recovery. Preoperatively establishing a patient’s risk profile could aid in perioperative care planning and preoperative decision-making.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00586-022-07325-5.

Lumbar instability as an etiology of low back pain and its treatment by prolotherapy: A review

BACKGROUND

Low back pain is a significant spinal disorder that affects much of the population at some point during their lives.

OBJECTIVE

While proper diagnosis is key, diagnosing the underlying cause of low back pain may often be unclear.

METHOD

In this review article, we discuss lumbar instability as an etiology of low back pain and its treatment by prolotherapy.

RESULTS

Spinal ligaments may be an underlying culprit in the development of lumbar instability with resultant low back pain and associated disorders.

CONCLUSION

In these cases, adequate treatment consisting of non-biologic prolotherapy or cellular prolotherapy, including platelet rich plasma (PRP), can be beneficial in restoring spinal stability and resolving chronic low back pain.

Influence of the geometric and material properties of lumbar endplate on lumbar interbody fusion failure: a systematic review

Background

Lumbar interbody fusion (LIF) is an established surgical intervention for patients with leg and back pain secondary to disc herniation or degeneration. Interbody fusion involves removal of the herniated or degenerated disc and insertion of interbody devices with bone grafts into the remaining cavity. Extensive research has been conducted on operative complications such as a failure of fusion or non-union of the vertebral bodies. Multiple factors including surgical, implant, and patient factors influencing the rate of complications have been identified. Patient factors include age, sex, osteoporosis, and patient anatomy. Complications can also be influenced by the interbody cage design. The geometry of the bony endplates as well as their corresponding material properties guides the design of interbody cages, which vary considerably across patients with spinal disorders. However, studies on the effects of such variations on the rate of complications are limited. Therefore, this study aimed to perform a systematic review of lumbar endplate geometry and material property factors in LIF failure.

Methods

Search keywords included ‘factor/cause for spinal fusion failure/cage subsidence/cage migration/non-union’, ‘lumbar’, and ‘interbody’ in electronic databases PubMed and Scopus with no limits on year of publication.

Results

In total, 1341 articles were reviewed, and 29 articles were deemed suitable for inclusion. Adverse events after LIF, such as cage subsidence, cage migration, and non-union, resulted in fusion failure; hence, risk factors for adverse events after LIF, notably those associated with lumbar endplate geometry and material properties, were also associated with fusion failure. Those risk factors were associated with shape, concavity, bone mineral density and stiffness of endplate, segmental disc angle, and intervertebral disc height.

Conclusions

This review demonstrated that decreased contact areas between the cage and endplate, thin and weak bony endplate as well as spinal diseases such as spondylolisthesis and osteoporosis are important causes of adverse events after LIF. These findings will facilitate the selection and design of LIF cages, including customised implants based on patient endplate properties.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03091-8.

Clinical outcome analysis in surgical patients enrolled in a Second Opinion Program in spine surgery

Objective

To analyze pain, functional capacity, quality of life, anxiety and depression outcomes in patients undergoing lumbar spine surgery following use of the Second Opinion Program, and to present disagreements regarding diagnoses and therapeutic indications between the first and second opinions.

Methods

A prospective, observational cohort study with 100 patients enrolled in the Second Opinion Program who underwent lumbar spine surgery. Questionnaires addressing pain intensity, level of disability, quality of life, anxiety and depression were applied prior to and within 1, 3, 6 and 12 months of surgery. Descriptive and comparative statistical analyses were performed. The following clinical outcomes were analyzed: pain intensity, level of disability, quality of life, anxiety, and depression.

Results

In this sample, 88% and 12% out of 100 patients were submitted to lumbar decompression and arthrodesis, respectively. Patients reported improvements in function, pain intensity, and quality of life factors following surgery and were able to attain the minimal clinically important difference relative to the preoperative period. Agreement between the first and second opinions was observed in 44% of diagnoses, and in 27% of therapeutic indications.

Conclusion

Patients had favorable postoperative outcomes regarding pain, disability, and quality of life. These findings and the high rates of diagnostic and therapeutic indication disagreements corroborate the need of a second opinion in cases of spine disease with surgical indications.

Surgical Treatments for Lumbar Spine Diseases (TLIF vs. Other Surgical Techniques): A Systematic Review and Meta-Analysis

Objective

The purpose of this study is to compare fusion rate, clinical outcomes, complications among transforaminal lumbar interbody fusion (TLIF), and other techniques for lumbar spine diseases.

Design

This is a systematic review and meta-analysis.

Data Sources

PubMed, EMBASE, Scopus, Web of Science, and CENTRAL databases were searched from January 2013 through December 2019.

Eligibility Criteria for Selecting Studies

Randomized controlled trials (RCTs) that compare lumbar interbody fusion with posterolateral fusion (PLF) and/or other lumbar interbody fusion were included for the review.

Data Extraction and Synthesis

Two independent reviewers extracted relevant data and assessed the risk of bias. Meta-analysis was performed using a random-effects model. Pooled risk ratio (RR) or mean difference (MD) with a 95% confidence interval of fusion rate, clinical outcomes, and complications in TLIF and other techniques for lumbar spinal diseases.

Results

Of 3,682 potential studies, 15 RCTs (915 patients) were included in the meta-analysis. Compared to other surgical techniques, TLIF had slightly lower fusion rate [RR = 0.84 (95% CI = 0.72–0.97), p = 0.02, I² = 0.0%] at 1-year follow-up whereas there was no difference on fusion rate at 2-year follow-up [RR = 1.06 (95% CI = 0.96–1.18), p = 0.27, I² = 69.0%]. The estimated RR of total adverse events [RR = 0.90 (95% CI = 0.59–1.38), p = 0.63, I² = 0.0%] was similar to no fusion, PLF, PLIF, and XLIF groups, and revision rate [RR = 0.78 (95% CI = 0.34–1.79), p = 0.56, I² = 39.0%] was similar to PLF and XLIF groups. TLIF had approximately half an hour more operative time than other techniques (no fusion, ALIF, PLF, PLIF, XLIF) [MD = 31.88 (95% CI = 5.33–58.44), p = 0.02, I² = 92.0%]. There was no significant difference between TLIF and other techniques in terms of blood loss (no fusion, PLIF, PLF) and clinical outcomes (PLF).

Conclusions

Besides fusion rate at 1-year follow-up and operative time, TLIF has a similar fusion rate, clinical outcomes, parameters concerning operation and complications to no fusion, PLF, and other interbody fusion (PLIF, ALIF, XLIF).

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42020186858.

Micromonas micros: A rare anaerobic cause of late implant failure following spinal surgery

Context: Delayed, postoperative, spine infections are rare, most commonly occurring secondary to fastidious, less virulent pathogens. The etiology may involve a distant infectious focus, not related to the index operation. Patients may present months, or even years postoperatively with pain related to mechanical implant failure, often without additional signs of systemic infection.Findings: We present the case of a 59-year-old male who developed rapid disk degeneration and implant failure seven months following instrumented lumbar fusion surgery. The causal organism was found to be Micromonas micros, an anaerobic bacterium typically located in the oral cavity and associated with periodontal disease. The patient was found to have extensive oral caries, which were presumed to have occurred secondary to poor oral hygiene and his use of fentanyl lozenges for chronic back pain. The patient was treated with revision staged spinal surgery and long-term intravenous antibiotics.Conclusion/clinical relevance: This case highlights an unusual etiology of delayed postoperative spinal implant failure and provides evidence for periodontal disease as a source of hematogenous seeding in postoperative spinal infections. The orthopaedist should also be aware of the potential relationship between poor oral hygiene and the use of high sugar content fentanyl lozenges in treating chronic back pain in these patients.

Formulation of Japanese Orthopaedic Association (JOA) clinical practice guideline for the management of low back pain- the revised 2019 edition

BACKGROUND

The latest clinical guidelines are mandatory for physicians to follow when practicing evidence-based medicine in the treatment of low back pain. Those guidelines should target not only Japanese board-certified orthopaedic surgeons, but also primary physicians, and they should be prepared based entirely on evidence-based medicine. The Japanese Orthopaedic Association Low Back Pain guideline committee decided to update the guideline and launched the formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline with the latest data of evidence-based medicine.

METHODS

The Japanese Orthopaedic Association Low Back Pain guideline formulation committee revised the previous guideline based on a method for preparing clinical guidelines in Japan proposed by Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Two key phrases, "body of evidence" and "benefit and harm balance" were focused on in the revised version. Background and clinical questions were determined, followed by literature search related to each question. Appropriate articles were selected from all the searched literature. Structured abstracts were prepared, and then meta-analyses were performed. The strength of both the body of evidence and the recommendation was decided by the committee members.

RESULTS

Nine background and nine clinical qvuestions were determined. For each clinical question, outcomes from the literature were collected and meta-analysis was performed. Answers and explanations were described for each clinical question, and the strength of the recommendation was decided. For background questions, the recommendations were described based on previous literature.

CONCLUSIONS

The 2019 clinical practice guideline for the management of low back pain was completed according to the latest evidence-based medicine. We strongly hope that this guideline serves as a benchmark for all physicians, as well as patients, in the management of low back pain.

Cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge versus iliac crest bone graft for lumbar degenerative disc disease in the United Kingdom

AIMS

To develop a model to evaluate the cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge (ACS) versus iliac crest bone graft (ICBG) in patients with lumbar degenerative disc disease in the United Kingdom.

MATERIALS & METHODS

A Markov decision-analytic model was constructed to calculate costs and quality-adjusted life-years over a 4-year time horizon in each treatment group, from a United Kingdom National Health Service perspective. An individual patient data meta-analysis was undertaken to synthesize data from four randomized controlled trials and two single-arm studies concerning health-related quality of life and procedural resource use. Current cost data from the United Kingdom were then applied to determine the overall mean cost per patient in each group. One-way and probabilistic sensitivity analyses were undertaken to explore the impact of parameter uncertainty.

RESULTS

The model predicted 4-year discounted cost savings of £192 per patient treated with dibotermin alfa/ACS, compared with ICBG, and a gain of 0.0114 QALYs per patient over the same time period. Sensitivity analyses indicated that the results were most sensitive to variability in the differences in health-related quality of life and secondary surgery rate, with dibotermin alfa/ACS having a 60% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained.

LIMITATIONS

There is uncertainty in the difference in cost and QALYs between the two groups. However, comprehensive sensitivity analyses were undertaken to explore this and present the results in a transparent manner.

CONCLUSIONS

Our results provide an economic case for the use of 4 mg dibotermin alfa/ACS versus iliac crest bone graft, with additional health benefits predicted at reduced overall cost.

Full-Endoscopic Posterior Lumbar Interbody Fusion with Epidural Anesthesia: Technical Note and Initial Clinical Experience with One-Year Follow-Up

Objective

The purpose of this study was to introduce and evaluate the early clinical outcomes of the full-endoscopic posterior lumbar interbody fusion (Endo-PLIF) technique with epidural anesthesia (EA) for single-segment lumbar degenerative diseases.

Methods

In this retrospective case series study, we explored the feasibility and effectiveness of the Endo-PLIF with EA for single-segment lumbar degenerative diseases. Between March 2018 and January 2019, a series of 24 patients with single-segment lumbar degenerative diseases underwent Endo-PLIF surgery and were followed up for a minimum of 12 months (15.21±2.27 months). Clinical outcomes including visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI) scores, and the Short Form-36 health survey questionnaire (SF-36) were evaluated preoperatively, and postoperatively at 3 days and at 3, 6, and 12-months.

Results

All patients underwent successful single-segment Endo-PLIF surgery. The mean operation time was 209.17±39.49 min, and average amount of bleeding was 43.33±14.87 mL. The VAS for lower extremity pain and back pain significantly improved at 3 days, and at 3, 6, 12 months compared with preoperative, respectively. The ODI scores decreased from 42.04±3.96 to 12.75±2.71 (P<0.001) at preoperative and 12 months postoperatively, respectively. The SF-36 Physical Component Scores (PCS) improved from 34.96±4.63 preoperatively to 52.08±6.05 (P<0.001) at 12 months postoperatively. Additionally, the SF-36 Mental Component Scores (MCS) improved from 39.38±5.70 at preoperative to 53.13±5.97 (P<0.001) at 12 months postoperatively. Two patients experienced dysesthesia, and one patient had a wound infection.

Conclusion

Endo-PLIF with EA is a feasible and valuable technique for the treatment of single-segment lumbar degenerative diseases in selected patients.

The Effect of the Severity of Preoperative Disability on Patient-Reported Outcomes and Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcomes (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement following minimally invasive transforaminal lumbar interbody fusion stratified by preoperative disability.

METHODS

Minimally invasive transforaminal lumbar interbody fusions were grouped by preoperative Oswestry Disability Index (ODI) score: ODI <41 or ODI ≥41. PROMs administered pre/postoperatively included Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), visual analog scale (VAS) back/leg, ODI, and 12-Item Short-Form Physical Composite Score (SF-12 PCS)/12-Item Short-Form Mental Composite Score (SF-12 MCS). Satisfaction scores were collected for VAS back/leg and ODI. Coarsened exact match controlled for differences between cohorts. T tests compared mean PROMs and postoperative improvement/satisfaction between cohorts. Simple logistic regression compared MCID achievement.

RESULTS

After coarsened exact matching, there were 118 patients in the ODI ≤41 and 377 patients in the ODI >41 cohort. The ODI >41 cohort saw greater postoperative inpatient VAS pain score and narcotic consumption on days 0/1 (P < 0.018, all). PROMs differed between cohorts: PROMIS-PF, SF-12 PCS, ODI, VAS back/leg at all postoperative time points and SF-12 MCS at 6 weeks/12 weeks/6 months/1 year (P < 0.045, all). Patients in the ODI >41 cohort demonstrated greater proportion achieving MCID for ODI at all postoperative time points and for SF-12 MCS 6-week/12-week/6-month/1-year (P < 0.040, all). The ODI ≤41 cohort demonstrated greater MCID achievement for overall PROMIS-PF and SF-12 PCS 6 months (P < 0.047, all). Postoperative satisfaction was greater in the ODI ≤41 cohort for VAS leg 6 weeks/12 weeks, VAS back 6 weeks/12 weeks, and ODI all postoperative time points (P < 0.048, all).

CONCLUSIONS

Preoperative disability associated with worse postoperative PROMs and patient satisfaction for disability, back/leg pain at multiple time points. MCID achievement rates across cohorts were similar for most PROMs at most postoperative time points. Patients with severe disability may have unrealistic expectations for surgical benefits, influencing corresponding postoperative satisfaction.

Lumbar Decompression Versus Spinal Fusion in a Private Outpatient Setting: A Retrospective Study with Three Years of Follow-up

Objective  To compare pain, function, quality of life and adverse events of lumbar decompression and spinal fusion in patients with degenerative spinal pathologies who participated in a second opinion program for spinal surgeries with a 36-month follow-up.

Methods  The data for this retrospective cohort were withdrawn from a private healthcare system between June 2011 and January 2014. The study sample consisted of 71 patients with a lumbar spine surgical referral. The outcomes for the comparisons between lumbar decompression and spinal fusion were quality of life (evaluated through the EuroQoL 5D), pain (measured by the Numerical Rating Scale) and function (assessed through the Roland Morris Disability Questionnaire) measured at baseline, and at 12 and 36 months after the surgical procedures. The definitions of recovery were established by the minimal clinically important difference (MCID). The baseline differences between the groups were analyzed by non-paired t -test, and the differences in instrument scores between time points, by generalized mixed models. The results were presented as mean values adjusted by the models and 95% confidence intervals.

Results  Concerning the surgical techniques, 22 patients were submitted to spinal fusion and 49 patients, to lumbar decompression. As for the comparisons of the findings before and after the surgical interventions, the MCID was achieved in all outcomes regarding quality of life, pain and function at both time points when compared to baseline scores Moreover, concerning the complication rates, only lumbar decompression presented a surgical rate of 4% ( n  = 3) for recurrence of lumbar disc hernia.

Conclusion  Patients with degenerative spinal pathologies present improvements in long-term outcomes of pain, function and quality of life which are clinically significant, no matter the surgical intervention.

Three-Dimensional-Printed Flexible Scaffolds Have Tunable Biomimetic Mechanical Properties for Intervertebral Disc Tissue Engineering

The intervertebral disc (IVD) exhibits complex structure and biomechanical function, which supports the weight of the body and permits motion. Surgical treatments for IVD degeneration (e.g., lumbar fusion, disc replacement) often disrupt the mechanical environment of the spine which lead to adjacent segment disease. Alternatively, disc tissue engineering strategies, where cell-seeded hydrogels or fibrous biomaterials are cultured in vitro to promote matrix deposition, do not recapitulate the complex IVD mechanical properties. In this study, we use 3D printing of flexible polylactic acid (FPLA) to fabricate a viscoelastic scaffold with tunable biomimetic mechanics for whole spine motion segment applications. We optimized the mechanical properties of the scaffolds for equilibrium and dynamic moduli in compression and tension by varying fiber spacing or porosity, generating scaffolds with de novo mechanical properties within the physiological range of spine motion segments. The biodegradation analysis of the 3D printed scaffolds showed that FPLA exhibits lower degradation rate and thus has longer mechanical stability than standard PLA. FPLA scaffolds were biocompatible, supporting viability of nucleus pulposus (NP) cells in 2D and in FPLA+hydrogel composites. Composite scaffolds cultured with NP cells maintained baseline physiological mechanical properties and promoted matrix deposition up to 8 weeks in culture. Mesenchymal stromal cells (MSCs) cultured on FPLA adhered to the scaffold and exhibited fibrocartilaginous differentiation. These results demonstrate for the first time that 3D printed FPLA scaffolds have de novo viscoelastic mechanical properties that match the native IVD motion segment in both tension and compression and have the potential to be used as a mechanically stable and biocompatible biomaterial for engineered disc replacement.

Health-Related Perceptions of Older Adults/Patients with Degenerative Lumbar Diseases (ODLs) are associated with their Quality of Life: a Mixed-Methods Study

PURPOSE

This study aimed to elucidate the quality of life of older adults/patients with degenerative lumbar diseases (ODLs) and analyse its association with some of their health-related perceptions.

MATERIALS AND METHODS

This mixed-methods study consisted of a questionnaire survey and an in-depth interview, which was designed within this study. ODLs were recruited from January 12, 2017 to June 27, 2018. The independent sample t-test and grounded theory coding method were employed for data analysis.

RESULTS

Of the 125 participants who returned valid questionnaires, 18 were included in the in-depth interviews. ODLs' quality of life was associated with the following health-related perceptions: "life barriers", "subjective health status", and "treatment outcomes" across the domains of physiology, psychology, social relations, and environment.

CONCLUSION

Our findings indicate that ODLs' quality of life is associated with their health-related perceptions. Thus, to improve older adults' quality of life, more attention should be paid to enhancing non-medical factors such as their health-related perceptions.

Exercise Therapy Using the Lumbar-Type Hybrid Assistive Limb Ameliorates Locomotive Function after Lumbar Fusion Surgery in an Elderly Patient

The number of elderly people who undergo lumbar fusion surgery (LFS) has been increasing. Postoperative rehabilitation for them can be problematic due to lumbar stiffness. This is the first case report describing exercise therapy using the lumbar-type hybrid assistive limb (HAL) after multiple LFS in an elderly patient. An 83-year-old man underwent LFS at L4-S1. Additional fusion surgery at L2-3 for adjacent segment disease was performed 2 years after the primary surgery. Although the patient's leg pain declined, he had severe locomotive dysfunction at 3 months after his final surgery. He started exercise therapy using the lumbar-type HAL including sit-to-stand training and squat training 4 months after his final surgery. He performed 3 sets of 20 sit-to-stand and 20 squat repetitions with adequate rests in between sets. The HAL training was safely conducted every day for 12 weeks without adverse event. Timed up and go test (TUG), 1-minute sit to stand test (1MSTS), one-leg stand test (OLST), and Berg balance scale (BBS) were assessed as locomotive function measurement. Before HAL therapy, TUG, 1MSTS, OLST, and BBS were 18.1 sec, 20 times, less than 1 sec, and 47, respectively. He could not walk without assistance. After the exercise therapy with the lumbar-type HAL, his locomotive function dramatically improved. TUG, 1MSTS, OLST, and BBS were 12.2 sec, 25 times, 3.9 sec, and 52, respectively. Moreover, the patient could walk 60 meters continuously without assistance. The unique characteristics of the lumbar-type HAL to prevent the lumbar overload and assist the voluntary hip joint motion during exercise therapy may be effective for this patient with lumbar stiffness after LFS. Sit-to-stand training and squat training using the lumbar-type HAL are promising options to improve locomotive function in elderly patients after LFS.

Results of a Pilot Study on the Safety and Early Efficacy of Novel Polymethyl Methacrylate Microspheres and a Hyaluronic Acid Device for the Treatment of Low Back Pain Caused by Degenerative and Diseased Intervertebral Discs of the Lumbar Spine

Background Low back pain (LBP) costs the healthcare system billions of dollars each year. Intervertebral disc (IVD) degeneration is a significant cause of LBP, due to structural defects, biomechanical instability, and inflammation. First-line therapy for patients with LBP includes physical therapy, medication, and steroid injections. DiscSealTM was developed to provide patients who are refractory to first-line therapy with a minimally invasive treatment alternative to invasive surgical procedures. The product is a combination of poly-methyl methacrylate (PMMA) microspheres in hyaluronic acid (HA) that is injected under modified discography into the IVD. Methods Two pain specialist centers in Australia recruited eligible participants who were followed up for 180 days post-procedure. The procedure was conducted using a modified discography technique. Low back and leg pain was reported using the Visual Analogue Scale (VAS) while other endpoints included were Oswestry Disability Index (ODI), Clinician and Patient Global Impact of Change, and Patient Rating of Overall Health Status. The general analytical approach for all endpoints was descriptive in nature and 95% confidence intervals of means were estimated. Results The pilot study achieved its primary objective which was an absence of peri-treatment or post-treatment device-related Serious Adverse Events (SAE) during the first 90 days. There were no device-related serious adverse events recorded throughout the study. The mean LBP percentage change from baseline at 90 and 180 days was -27.0% and -42.3% respectively. The mean ODI percentage change from baseline at 90 and 180 days was -22.3 and -14.2% respectively. End of study improvements shows a 67.8% (20.83) increase in Overall Health Status, as well as positive results for Participant and Clinician Global Impact of Change. These results were achieved based on treating one diseased IVD, although 83.3% of patients were diagnosed with multiple diseased IVDs. Conclusions The results from this pilot study showed that DiscSealTM is safe and well-tolerated. Early efficacy shows that DiscSealTM may be a promising treatment option for people suffering from discogenic LBP that have not responded to first-line treatment options. A larger, statistically powered study where all diseased discs are treated should be completed to validate the promising results from this early feasibility study.

Safety of Lumbar Interbody Fusion Procedures for Degenerative Disc Disease: A Systematic Review With Network Meta-Analysis of Prospective Studies

STUDY DESIGN

A network meta-analysis.

OBJECTIVES

Lumbar degenerative disc disease (LDDD) is an important issue in aging population, for which lumbar interbody fusion (LIF) is a feasible management in cases refractory to conservative therapy. There are various techniques available to perform LIF, including posterior (PLIF), transforaminal (TLIF), and anterior (ALIF) approaches. However, the comparative safety profile of these procedures remains controversial. Our study aimed to evaluate comparative adverse events of the LIF procedures in patients with LDDD.

METHODS

We searched 5 databases for relevant prospective cohort studies and randomized clinical trials. After quality assessments, we extracted neural, spinal, vascular, and wound events for conducting contrast-based network meta-analysis. Results were reported in risk ratio (RR), 95% confidence interval (CI), and surface under the cumulative ranking (SUCRA).

RESULTS

We identified 14 studies involving 921 participants with LDDD. Pooled result showed that open PLIF (OPLIF) leads to significantly higher overall adverse event rate than does open TLIF (OTLIF; RR = 3.43, 95% CI = 1.21-9.73). OTLIF confers the highest SUCRA in neural (78.7) and spinal (80.8) event rates. Minimally invasive TLIF has the highest SUCRA in vascular event (84.2), and minimally invasive PLIF has the highest SUCRA in wound event (88.1). No inconsistency or publication bias was detected in the results.

CONCLUSIONS

Based on our results, perhaps OPLIF should be avoided in the management of LDDD due to the inferiority of overall complications. Specifically, TLIF seems to have the safest profile in terms of neural, spinal, and vascular events. Nevertheless, shared decision making is still mandatory when choosing the proper LIF procedure for patients with LDDD in clinical practice.

A 15-Year Follow-up Retrospective Study on 959 Spine Surgeries: What Can We Learn From Real-world Data?

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

The aim of this study was to investigate the patient flow and need for additional surgery after first-time lower back surgery. Next, we analyzed the patients who developed chronic low back pain (LBP) and were treated with spinal cord stimulation.

SUMMARY OF BACKGROUND DATA

LBP has a lifetime prevalence of 84% and imposes a high economic burden. Treatment is focused on preventing chronic pain. Research has shown the efficacy of treatment options. However, less is known about who benefits the most from which therapy and when they should be positioned in the treatment algorithm.

METHODS

In this retrospective study, data of all patients who underwent first-time surgery from 2000 to 2004 were included. After 10-15 years, patients were contacted about their quality of life (QoL) (EuroQoL-5 Dimension) and life and heath perception (EuroQoL Visual Analogue Scale).

RESULTS

In all, 959 patients underwent surgery at the lower back area. Follow-up time ranged from 13 to 17 years; 225 patients (23.5%) underwent a second surgery. In total, 20 patients (2.1%) developed chronic neuropathic back pain and received spinal cord stimulation therapy. Ten years postsurgery, 438 (45.7%) patients completed the QoL and LBP questionnaires. The health-related QoL and health situation were significantly lower in patients with multiple surgeries ( P <0.001).

CONCLUSIONS

The study results indicate that large data sets, with multiple outcome measurements and long-term follow-up are necessary to improve our knowledge and to optimize the therapeutic pathway. In that way, we might learn how to select a patient for the right treatment or treatments at the right moment and shorten the circulation in our health care system.

Pain Self-Management Strategies of Chronic Back Pain Sufferers in Thailand: A Qualitative Study (A Doctoral Project)

Background:

Chronic low back pain is among the most common chronic musculoskeletal disorders worldwide. It is prevalent in Thailand, affecting up to 30% of the general population, with much higher rates among manual labourers. Pain self-management, including education, exercise, medication and other components, is an effective strategy for reducing pain intensity and disability rates for chronic low back pain sufferers.

Objective:

To investigate pain self-management strategies among chronic lower back pain sufferers in Thailand.

Methods:

The study design was a qualitative interview-based technique. The study setting was an orthopaedic outpatient department at a university hospital in Northern Thailand. Participants (n = 19) were selected based on recruitment criteria, and data was collected using demographic forms and in-depth interviews. Thematic analysis was used for qualitative analysis, with Wilcoxon signed-rank test used to assess changes in pain levels.

Results:

Participants used a combination of pain self-management modalities, including exercise, modified food consumption, increased rest, herbal treatments, hot and cold compression, Thai massage, and acupressure, along with psychological and spiritual coping tools like meditation and making merit. Ability to use these interventions was dependent on medical support from practitioners as well as social and other support. A small, but significant, mean difference in pain was also observed.

Conclusion:

Findings point to the possibility that there are significant cultural differences in pain self-management modalities and their effectiveness.

S100A9 induces nucleus pulposus cell degeneration through activation of the NF-κB signaling pathway

Oxidative stress in the lumbar disc leads to the degeneration of nucleus pulposus (NP). However, the molecular mechanisms underlying this process remain unclear. In this study, we delineated a key calcium-binding protein, S100A9, which was induced by oxidative stress and was highly expressed in the degenerative NP. Immunofluorescence staining and Western blotting revealed that S100A9 induced NP cell apoptosis in vitro by up-regulating the expression of pro-apoptotic markers, including cleaved caspase-3, cytochrome c and Bax. Moreover, RT-PCR analyses revealed that the expression of S100A9 caused NP matrix degradation by up-regulating the expression of matrix degradation enzymes and increased the inflammatory response by up-regulating cytokine expression. Therefore, S100A9 induced NP cell degeneration by exerting pro-apoptotic, pro-degradation and pro-inflammatory effects. The detailed mechanism underlying S100A9-induced NP degeneration was explored by administering SC75741, a specific NF-κB inhibitor in vitro. We concluded that S100A9 induced NP cell apoptosis, caused matrix degradation and amplified the inflammatory response through the activation of the NF-κB signalling pathway. Inhibition of these pro-apoptotic, pro-degradation and pro-inflammatory effects induced by S100A9 in NP may be a favourable therapeutic strategy to slow lumbar disc degeneration.

Low-Dose MDCT of Patients With Spinal Instrumentation Using Sparse Sampling: Impact on Metal Artifacts

OBJECTIVE. The purpose of our study was to evaluate simulated sparse-sampled MDCT combined with statistical iterative reconstruction (SIR) for low-dose imaging of patients with spinal instrumentation. MATERIALS AND METHODS. Thirty-eight patients with implanted hardware after spinal instrumentation (24 patients with short- or long-term instrumentation-related complications [i.e., adjacent segment disease, screw loosening or implant failure, or postoperative hematoma or seroma] and 14 control subjects with no complications) underwent MDCT. Scans were simulated as if they were performed with 50% (P50), 25% (P25), 10% (P10), and 5% (P5) of the projections of the original acquisition using an in-house-developed SIR algorithm for advanced image reconstructions. Two readers performed qualitative image evaluations of overall image quality and artifacts, image contrast, inspection of the spinal canal, and diagnostic confidence (1 = high, 2 = medium, and 3 = low confidence). RESULTS. Although overall image quality decreased and artifacts increased with reductions in the number of projections, all complications were detected by both readers when 100% of the projections of the original acquisition (P100), P50, and P25 imaging data were used. For P25 data, diagnostic confidence was still high (mean score ± SD: reader 1, 1.2 ± 0.4; reader 2, 1.3 ± 0.5), and interreader agreement was substantial to almost perfect (weighted Cohen κ = 0.787-0.855). The mean volumetric CT dose index was 3.2 mGy for P25 data in comparison with 12.6 mGy for the original acquisition (P100 data). CONCLUSION. The use of sparse sampling and SIR for low-dose MDCT in patients with spinal instrumentation facilitated considerable reductions in radiation exposure. The use of P25 data with SIR resulted in no missed complications related to spinal instrumentation and allowed high diagnostic confidence, so using only 25% of the projections is probably enough for accurate and confident diagnostic detection of major instrumentation-related complications.

Effects of a multimodal exercise intervention on physical and cognitive functions in patients with chronic low back pain (MultiMove): study protocol for a randomized controlled trial

BACKGROUND

Chronic low back pain (CLBP) is a common medical condition in adults over the age of 50. It is associated with severe disability, ranging from physical impairments to psychosocial distress. Since current treatments provide only small to moderate short-term effects, alternative interventions are required, whereby guidelines recommended multimodal approaches. Dancing can be considered as an inherently multimodal approach, as it requires a combination of physical and cognitive functions. Furthermore, it has already been applied effectively in neurorehabilitation. Therefore, it seems promising to merge a dance-therapeutic component together with motor-cognitive, strength and flexibility exercises in a novel multimodal treatment (MultiMove) to target the impaired everyday mobility and cognition of CLBP patients. The aim of this study is to analyse specific physical, cognitive and psychosocial effects of MultiMove in CLBP patients.

METHODS

A prospective, two-arm, single-blinded, randomized controlled trial will be conducted with an estimated sample size of 100 CLBP patients, assigned to either the MultiMove group or a control group. The intervention group will receive MultiMove twice a week for 60 min each over a period of 12 weeks. The primary outcome will be the mobility and function of the lower extremities assessed by the Timed Up-and-Go Test. Secondary outcomes comprise further physical and physiological functions (e.g. gait variability and haemodynamic response in the prefrontal cortex during motor-cognitive dual tasks), subjective health state (e.g. disability in daily life), executive functions (e.g. cognitive flexibility) and psychosocial aspects (e.g. kinesiophobia). Measures will be taken at baseline, after the intervention and at a 12-week follow-up. It is assumed that MultiMove improves the mentioned outcome parameters.

DISCUSSION

The combined assessment of changes in physical and cognitive functions as well as neuropsychological aspects in response to MultiMove will allow a better understanding of the motor-cognitive adaptations induced by multimodal exercises in CLBP patients. The specific conclusions will lead to recommendations for the conservative treatment approach in this clinically relevant patient group.

TRIAL REGISTRATION

German Clinical Trial Register (ID: DRKS00021696 / 10.07.2020), https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021696.

Current Prehabilitation Programs Do Not Improve the Postoperative Outcomes of Patients Scheduled for Lumbar Spine Surgery: A Systematic Review With Meta-analysis

OBJECTIVE

To assess the effectiveness of prehabilitation in patients with degenerative disorders of the lumbar spine who are scheduled for spine surgery.

DESIGN

Intervention systematic review with meta-analysis.

LITERATURE SEARCH

Seven electronic databases were systematically searched for randomized controlled trials or propensity-matched cohorts.

STUDY SELECTION CRITERIA

Studies that measured the effect of prehabilitation interventions (ie, exercise therapy and cognitive behavioral therapy [CBT]) on physical functioning, pain, complications, adverse events related to prehabilitation, health-related quality of life, psychological outcomes, length of hospital stay, use of analgesics, and return to work were included.

DATA SYNTHESIS

Data were extracted at baseline (preoperatively) and at short-term (6 weeks or less), medium-term (greater than 6 weeks and up to 6 months), and long-term (greater than 6 months) follow-ups. Pooled effects were analyzed as mean differences and 95% confidence intervals (CIs). Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

Cognitive behavioral therapy interventions were no more effective than usual care for all outcomes. Pooled effect sizes were -2.0 (95% CI: -4.4, 0.4) for physical functioning, -1.9 (95% CI: -5.2, 1.4) for back pain, and -0.4 (95% CI: -4.1, 0.4) for leg pain. Certainty of evidence for CBT ranged from very low to low. Only 1 study focused on exercise therapy and found a positive effect on short-term outcomes.

CONCLUSION

There was very low-certainty to low-certainty evidence of no additional effect of CBT interventions on outcomes in patients scheduled for lumbar surgery. Existing evidence was too limited to draw conclusions about the effects of exercise therapy. J Orthop Sports Phys Ther 2021;51(3):103-114. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9748.

Advances in Tissue Engineering for Disc Repair

Intervertebral disc (IVD) degeneration is a leading cause of chronic low back pain (LBP) that results in serious disability and significant economic burden. IVD degeneration alters the disc structure and spine biomechanics, resulting in subsequent structural changes throughout the spine. Currently, treatments of chronic LBP due to IVD degeneration include conservative treatments, such as pain medication and physiotherapy, and surgical treatments, such as removal of herniated disc without or with spinal fusion. However, none of these treatments can completely restore a degenerated disc and its function. Thus, although the exact pathogenesis of disc degeneration remains unclear, there are studies examining the effectiveness of biological approaches, such as growth factor injection, gene therapy, and cell transplantation, in promoting IVD regeneration. Furthermore, tissue engineering using a combination of cell transplantation and biomaterials has emerged as a promising new approach for repair or restoration of degenerated discs. The main purpose of this review was to provide an overview of the current status of tissue engineering applications for IVD regenerative therapy by performing literature searches using PubMed. Significant advances in tissue engineering have opened the door to a new generation of regenerative therapies for the treatment of chronic discogenic LBP.

Comparison of Clinical Outcomes Between Posterior Instrumented Fusion With and Without Interbody Fusion for Isthmic Spondylolisthesis

STUDY DESIGN

A multicenter ambispective study using the Canadian Spine Outcomes and Research Network to compare clinical outcomes in adult patients with isthmic spondylolisthesis who received surgery.

OBJECTIVE

The purpose of this study is to compare 1-year postoperative clinical outcomes between posterior instrumented fusion with and without interbody fusion in patients with isthmic spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Despite the increased use of interbody fusion in patients with isthmic spondylolisthesis, clinical superiority has not been demonstrated. It remains unclear what the optimal surgical approach is for this population.

MATERIALS AND METHODS

The primary outcome was changed in leg pain at 1 year. Secondary outcomes were changed in Oswestry Disability Index, Short Form-12 Physical Component Score, and back pain at 1-year postoperative follow-up, estimated intraoperative blood loss, length of surgery, length of stay, number of transfusions, and adverse events. Descriptive statistics, Student t test, χ2 test, and stepwise multivariable regression were used for analysis.

RESULTS

In total, 300 patients were included in this study. Of the 300 patients, 252 received posterolateral instrumented fusion with interbody fusion and 48 received posterolateral instrumented fusion alone. There were no significant differences in primary and secondary clinical outcomes at 1-year postoperative follow-up between the 2 groups. There were no significant differences in estimated blood loss (441 vs. 356 mL), length of surgery (210 vs. 224 min), length of stay (4 vs. 4 d), rate of transfusions (5.6% vs. 8.3%), and number of adverse events (33% vs. 23%) between patients who received interbody fusion and patients who did not. The addition of interbody fusion was not a significant variable for primary and secondary clinical outcomes in the stepwise multivariable regression analysis.

CONCLUSIONS

There were no significant differences in clinical outcomes at 1 year or in the number of early complications between patients who received posterolateral fusion or posterior/transformational lumbar interbody fusion.

LEVEL OF EVIDENCE

Level III.

Trends in Pain Medication Prescriptions and Satisfaction Scores in Spine Surgery Patients at a Single Institution

BACKGROUND

As the opioid crisis has gained national attention, there have been increasing efforts to decrease opioid usage. Simultaneously, patient satisfaction has been a crucial metric in the American health care system and has been closely linked to effective pain management in surgical patients. The purpose of this study was to examine rates of pain medication prescription and concurrent patient satisfaction in spine surgery patients.

METHODS

A total of 1729 patients undergoing spine surgery between June 25, 2017, and June 30, 2018, at a single institution by surgeons performing ≥20 surgeries per quarter, with medication data during hospitalization available, were assessed. Patients were evaluated for nonopioid pain medication prescription rates and morphine milligram equivalents (MME) of opioids used during hospitalization. Of the total cohort, 198 patients were evaluated for Press Ganey Satisfaction Survey responses. A χ² test of independence was used to compare percentages, and 1-way analysis of variance was used to compare means across quarters.

RESULTS

The mean total MME per patient hospitalization was 574.46, with no difference between quarters. However, mean MME per day decreased over time (P = .048), with highest mean 91.84 in Quarter 2 and lowest 77.50 in Quarter 4. Among all procedures, acetaminophen, nonsteroidal anti-inflammatory drugs, and steroid prescription rates increased, whereas benzodiazepine and γ-aminobutyric acid-analog prescriptions decreased. There were no significant differences between quarters for mean hospital ratings (P = .521) nor for responses to questions from the Press Ganey Satisfaction Survey regarding how often staff talk about pain (P = .164), how often staff talk about pain treatment (P = .595), or whether patients recommended the hospital (P = .096). There were also no differences between quarters for responses in all other patient satisfaction questions (P value range, .359-.988).

CONCLUSIONS

Over the studied time period, opioid use decreased and nonopioid prescriptions increased during hospitalization, whereas satisfaction scores remained unchanged. These findings indicate an increasing effort in reducing opioid use among providers and suggest the ability to do so without affecting overall satisfaction rates.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

The opioid epidemic has highlighted the need to reduce opioid usage in orthopedic spine surgery. This study reviews the trends for inpatient management of post-op pain in orthopedic spine surgery patients in relation to patient satisfaction. There was a significant increase in non-opioid analgesic pain medications, and a reduction in opioids during the study period. During this time, patient satisfaction as measured by Press-Ganey surveys did not show a decrease. This demonstrates that treatment of post-operative pain in orthopedic spine surgery patients can be managed with less opioids, more multimodal analgesia, and patient satisfaction will not be affected.

Multicentre randomised controlled clinical trial of electroacupuncture with usual care for patients with non-acute pain after back surgery

BACKGROUND

The purpose of this study was to investigate the effectiveness and safety between electroacupuncture (EA) combined with usual care (UC) and UC alone for pain reduction and functional improvement in patients with non-acute low back pain (LBP) after back surgery.

METHODS

In this multicentre, randomised, assessor-blinded active-controlled trial, 108 participants were equally randomised to either the EA with UC or the UC alone. Participants in the EA with UC group received EA treatment and UC treatment twice a week for 4 weeks; those allocated to the UC group received only UC. The primary outcome was the VAS pain intensity score. The secondary outcomes were functional improvement (Oswestry Disability Index [ODI]) and the quality of life (EuroQol-5-dimension questionnaire [EQ-5D]). The outcomes were measured at Week 5.

RESULTS

Significant reductions were observed in the VAS (mean difference [MD] -8.15; P=0.0311) and ODI scores (MD -3.98; P=0.0460) between two groups after 4 weeks of treatment. No meaningful differences were found in the EQ-5D scores and incidence of adverse events (AEs) between the groups. The reported AEs did not have a causal relationship with EA treatment.

CONCLUSIONS

The results showed that EA with UC treatment was more effective than UC alone and relatively safe in patients with non-acute LBP after back surgery. EA with UC treatment may be considered as an effective, integrated, conservative treatment for patients with non-acute LBP after back surgery.

CLINICAL TRIAL REGISTRATION

KCT0001939.

DOES DECUBITUS AFFECT NEURAL ELEMENTS POSITIONING? A MRI STUDY COMPARING DORSAL AND LATERAL POSITION

ABSTRACT Objective To evaluate the displacement of nerve structures according to the decubitus position of the patient in a magnetic resonance imaging (MRI) study. Methods MRI was performed at a radiology clinic in 20 patients in dorsal and right lateral decubitus. The measurement considered was the shortest distance between the dura mater and the medial wall of the pedicle. Results The largest measurement was 11.6 mm in left lateral decubitus, 12.2 mm in right lateral decubitus, 10.5 mm in right dorsal decubitus, and 9.2 mm in left dorsal decubitus. In some patients the space between the medial wall of the pedicle and the dura mater was larger when in lateral decubitus, while in others when in dorsal decubitus. The mean displacement of the measurements on the left was 1.14 mm and on the right 1.355 mm. Conclusions The structures moved on average little more than 1 mm in the positions studied. The positioning of the patient for surgery does not change the space to be approached, being the surgeon’s choice according to his learning curve. Level of evidence II; Prospective study of lower quality.

Is Lumbar Fusion Necessary for Chronic Low Back Pain Associated with Degenerative Disk Disease? A Meta-Analysis

OBJECTIVE

We sought to evaluate the efficacy and safety of lumbar fusion versus nonoperative care for the treatment of chronic low back pain associated with degenerative disk disease.

METHODS

A comprehensive duplicate electronic database search including PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure was conducted to identify relevant prospective studies published up to June 30, 2020. The main outcomes including clinical results, complications, and all-cause additional surgeries were presented in the form of short- (<2 years) and long-term (≥2 years) follow-up results. Analyses were performed in Review Manager software 5.3.

RESULTS

Six prospective studies involving 159 patients for short-term follow-up and 675 for long-term follow-up were included. The 2 interventions exhibited little difference in regard to short- and long-term Oswestry Disability Index and visual analog scale scores for back and leg pain, except that lumbar fusion might bring about lower additional surgery rate (risk ratio, 0.40; 95% confidence interval, 0.17 to 0.98; P = 0.04), and higher complication rate (risk ratio, 21.46; 95% confidence interval, 4.34 to 106.04; P = 0.0002) in the long term.

CONCLUSIONS

The present meta-analysis determined that fusion surgery was no better than nonoperative treatment in terms of the pain and disability outcomes at either short- or long-term follow-up. It is necessary for clinicians to weigh the risk of complications associated with fusion surgery against additional surgeries after nonoperative treatment. Considering lax patient inclusion criteria in the existing randomized clinical trials, the result needs to be further confirmed by high-quality research with stricter selection criteria in the future.

Early postoperative physical activity and function: a descriptive case series study of 53 patients after lumbar spine surgery

BACKGROUND

The purpose of this prospective case series study was to compare changes in early postoperative physical activity and physical function between 6 weeks and 3 and 6 months after lumbar spine surgery.

METHODS

Fifty-three patients (mean [95% confidence interval; CI] age = 59.2 [56.2, 62.3] years, 64% female) who underwent spine surgery for a degenerative lumbar condition were assessed at 6 weeks and 3- and 6-months after surgery. The outcomes were objectively-measured physical activity (accelerometry) and patient-reported and objective physical function. Physical activity was assessed using mean steps/day and time spent in moderate to vigorous physical activity (MVPA) over a week. Physical function measures included Oswestry Disability Index (ODI), 12-item Short Form Health Survey (SF-12), Timed Up and Go (TUG), and 10-Meter Walk (10 MW). We compared changes over time in physical activity and function using generalized estimating equations with robust estimator and first-order autoregressive covariance structure. Proportion of patients who engaged in meaningful physical activity (e.g., walked at least 4400 and 6000 steps/day or engaged in at least 150 min/week in MVPA) and achieved clinically meaningful changes in physical function were compared at 3 and 6 months.

RESULTS

After surgery, 72% of patients initiated physical therapy (mean [95%CI] sessions =8.5 [6.6, 10.4]) between 6 weeks and 3 months. Compared to 6 weeks post-surgery, no change in steps/day or time in MVPA/week was observed at 3 or 6 months. From 21 to 23% and 9 to 11% of participants walked at least 4400 and 6000 steps/day at 3 and 6 months, respectively, while none of the participants spent at least 150 min/week in MVPA at these same time points. Significant improvements were observed on ODI, SF-12, TUG and 10 MW (p <  0.05), with over 43 to 68% and 62 to 87% achieving clinically meaningful improvements on these measures at 3 and 6 months, respectively.

CONCLUSION

Limited improvement was observed in objectively-measured physical activity from 6 weeks to 6 months after spine surgery, despite moderate to large function gains. Early postoperative physical therapy interventions targeting physical activity may be needed.

Balancing biological and biomechanical performance in intervertebral disc repair: a systematic review of injectable cell delivery biomaterials

Discogenic back pain is a common condition without approved intervertebral disc (IVD) repair therapies. Cell delivery using injectable biomaterial carriers offers promise to restore disc height and biomechanical function, while providing a functional niche for delivered cells to repair degenerated tissues. This systematic review advances the injectable IVD cell delivery biomaterials field by characterising its current state and identifying themes of promising strategies. Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines were used to screen the literature and 183 manuscripts met the inclusion criteria. Cellular and biomaterial inputs, and biological and biomechanical outcomes were extracted from each study. Most identified studies targeted nucleus pulposus (NP) repair. No consensus exists on cell type or biomaterial carrier, yet most common strategies used mesenchymal stem cell (MSC) delivery with interpenetrating network/co-polymeric (IPN/CoP) biomaterials composed of natural biomaterials. All studies reported biological outcomes with about half the studies reporting biomechanical outcomes. Since the IVD is a load-bearing tissue, studies reporting compressive and shear moduli were analysed and two major themes were found. First, a competitive balance, or 'seesaw' effect, between biomechanical and biological performance was observed. Formulations with higher moduli had inferior cellular performance, and vice versa. Second, several low-modulus biomaterials had favourable biological performance and matured throughout culture duration with enhanced extracellular matrix synthesis and biomechanical moduli. Findings identify an opportunity to develop next-generation biomaterials that provide high initial biomechanical competence to stabilise and repair damaged IVDs with a capacity to promote cell function for long-term healing.