Intravoxel incoherent motion imaging predicts exercise-based rehabilitation response in individuals with low back pain.

Exercises to strengthen and stabilize the trunk musculature are a common conservative treatment strategy for low back pain (LBP), despite the possible presence of impairments in muscle activation in this population. Intravoxel incoherent motion (IVIM) MRI permits evaluation of activation-induced blood flow through diffusion-weighted images that are sensitized to microvascular blood flow. In the current study we aimed to evaluate IVIM signal changes after exercise in patients with LBP compared with pain-free healthy controls and determine if these changes were related to reductions in disability with a 12-week rehabilitation program. We hypothesize that the magnitude of changes in IVIM parameters in the lumbar extensor muscles will be smaller in patients with LBP compared with those without LBP, and that these magnitudes will be correlated with responsiveness to a 12-week, resistance-based exercise program. IVIM MR data for molecular diffusion (D), blood flow pseudodiffusion (D*) and perfusion fraction (f) were collected before and immediately after an ~ 3-min session of high-intensity lumbar extension resistance exercise in 16 healthy participants and 17 participants with LBP. Improvements in LBP-related disability after the 12-week, machine-based, high-intensity exercise rehabilitation program were measured in the LBP group. We observed a significant increase in all IVIM parameters (f, D*, D) in response to exercise (p < 0.0001) and an interaction of group-by-time for D (p = 0.016). Thresholds were identified using receiver operating characteristic (ROC) curves for diffusion and pseudodiffusion coefficients, which predicted a reduction in LBP-related disability in response to the 12-week, exercise-based rehabilitation program. Exercise was associated with an increase in (f), capillary blood flow-based pseudodiffusion (D*) and diffusion coefficient (D), regardless of the presence of LBP. Additionally, subgroup analysis identified patients who were not responsive to the acute exercise session, for whom, based on ROC analysis, there was no clinically significant change in disability following the 12-week program.

In-Clinic Versus Web-Based Multidisciplinary Exercise-Based Rehabilitation for Treatment of Low Back Pain: Prospective Clinical Trial in an Integrated Practice Unit Model.

BACKGROUND: The recent onset of the COVID-19 pandemic has highlighted the need to reduce barriers to access physical therapy and associated care through the use of web-based programs and telehealth for those seeking treatment for low back pain (LBP). Despite this need, few studies have compared the effectiveness of clinic-based versus web-based or telehealth services. OBJECTIVE: This study aims to compare the clinical outcomes of clinic-based multidisciplinary therapy in an integrated practice unit (C-IPU) model with online integrated multidisciplinary therapy (O-IPU) in individuals undergoing conservative care for LBP. METHODS: A total of 1090 participants were prospectively recruited to participate in a clinical trial registry (NCT04081896) through the SpineZone rehabilitation IPU program. All participants provided informed consent. Participants were allocated to the C-IPU (N=988) or O-IPU (N=102) groups based on their personal preferences. The C-IPU program consisted of a high-intensity machine-based core muscle resistance training program, whereas the O-IPU program consisted of therapist-directed home core strengthening exercises through a web-based platform. Changes in LBP symptom severity (Numeric Pain Rating Scale), disability (Oswestry Disability Index), goal achievement (Patient-Specific Functional Scale), and frequency of opioid use were compared between the C-IPU and O-IPU groups using multivariate linear regression modeling adjusted for age, gender, treatment number, program duration, and baseline pain and disability. RESULTS: Approximately 93.03% (1014/1090) of the participants completed their recommended programs, with no group differences in dropout rates (P=.78). The C-IPU group showed greater pain relief (P<.001) and reductions in disability (P=.002) than the O-IPU group, whereas the O-IPU group reported greater improvements in goal achievement (P<.001). Both programs resulted in reduced opioid use frequency, with 19.0% (188/988) and 21.5% (22/102) of participants reporting cessation of opioid use for C-IPU and O-IPU programs, respectively, leaving only 5.59% (61/1090) of participants reporting opioid use at the end of their treatment. CONCLUSIONS: Both in-clinic and web-based multidisciplinary programs are beneficial in reducing pain, disability, and opioid use and in improving goal achievement. The differences between these self-selected groups shed light on patient characteristics, which require further investigation and could help clinicians optimize these programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04081896; https://clinicaltrials.gov/ct2/show/NCT04081896.

Factors impacting adherence to an exercise-based physical therapy program for individuals with low back pain.

BACKGROUND/OBJECTIVE: Exercise-based rehabilitation is a conservative management approach for individuals with low back pain. However, adherence rates for conservative management are often low and the reasons for this are not well described. The objective of this study was to evaluate predictors of adherence and patient-reported reasons for non-adherence after ceasing a supervised exercise-based rehabilitation program in individuals with low back pain. DESIGN: Retrospective observational study. METHODS: Data was retrospectively analyzed from 5 rehabilitation clinics utilizing a standardized exercise-based rehabilitation program. Baseline demographics, diagnosis and symptom specific features, visit number, and discontinuation profiles were quantified for 2,243 patients who underwent the program. RESULTS: Forty-three percent (43%) of participants were adherent to the program, with the majority (31.7%) discontinuing treatment prior to completion due to logistic and accessibility issues. Another 13.2% discontinued prior to the prescribed duration due to clinically significant improvements in pain and/or disability without formal discharge evaluation, whereas 8.3% did not continue due to lack of improvement. Finally, 6.0% were discharged for related and unrelated medical reasons including surgery. Individuals diagnosed with disc pathology were most likely to be adherent to the program. LIMITATIONS: This study was a retrospective chart review with missing data for some variables. Future studies with a prospective design would increase quality of evidence. CONCLUSIONS: The majority of individuals prescribed an in-clinic exercise-based rehabilitation program are non-adherent. Patient diagnosis was the most important predictor of adherence. For those who were not adherent, important barriers include personal issues, insufficient insurance authorization and lack of geographic accessibility.

The effect of anterior longitudinal ligament resection on lordosis correction during minimally invasive lateral lumbar interbody fusion: Biomechanical and radiographic feasibility of an integrated spacer/plate interbody reconstruction device.

BACKGROUND: Lateral lumbar interbody fusion is powerful for correcting degenerative conditions, yet sagittal correction remains limited by anterior longitudinal ligament tethering. Although lordosis has been restored via ligament release, biomechanical consequences remain unknown. Investigators examined radiographic and biomechanical of ligament release for restoration of lumbar lordosis. METHODS: Six fresh-frozen human cadaveric spines (L3-S1) were tested: (Miller et al., 1988) intact; (Battie et al., 1995) 8mm spacer with intact anterior longitudinal ligament; (Cho et al., 2013) 8mm spacer without intact ligament following ligament resection; (Galbusera et al., 2013) 13mm lateral lumbar interbody fusion; (Goldstein et al., 2001) integrated 13mm spacer. Focal lordosis and range of motion were assessed by applying pure moments in flexion-extension, lateral bending, and axial rotation. FINDINGS: Cadaveric radiographs showed significant improvement in lordosis correction following ligament resection (P<0.05). The 8mm spacer with ligament construct provided greatest stability relative to intact (P>0.05) but did little to restore lordosis. Ligament release significantly destabilized the spine relative to intact in all modes and 8mm with ligament in lateral bending and axial rotation (P<0.05). Integrated lateral lumbar interbody fusion following ligament resection did not significantly differ from intact or from 8mm with ligament in all testing modes (P>0.05). INTERPRETATION: Lordosis corrected by lateral lumbar interbody fusion can be improved by anterior longitudinal ligament resection, but significant construct instability and potential implant migration/dislodgment may result. This study shows that an added integrated lateral fixation system can significantly improve construct stability. Long-term multicenter studies are needed.

Outcome Measures of an Intracanal, Endoscopic Transforaminal Decompression Technique: Initial Findings from the MIS Prospective Registry.

BACKGROUND: Minimally invasive transforaminal endoscopic procedures can achieve spinal decompression through either direct or indirect techniques. Subtle variations in trajectory of the surgical corridor can dictate access to the pathologic tissue. Two general strategies exist: the intradiscal "inside-out" technique and the extradiscal, intracanal (IC) technique. The IC technique utilizes a more lateral transforaminal approach than the intradiscal technique, which allows for a more direct decompression of the spinal canal. OBJECTIVE: This study is an assessment of IC patient outcome data obtained through analysis of a previously validated MIS Prospective Registry. METHODS: Post-hoc analysis was performed on the MIS Prospective Registry database containing 1032 patients. A subgroup of patients treated with the endoscopic IC technique was identified. Patient outcome measures after treatment of symptomatic disk herniation and neuroforaminal stenosis were evaluated. RESULTS: A total of 86 IC patients were analyzed. Overall, there was significant improvement in employment and walking tolerance as soon as 6 weeks post-op as well as significant one year VAS and ODI score improvement. Subanalysis of IC patients with two distinct primary diagnoses was performed. Group IC-1 (disc herniation) showed improvement in ODI and VAS back and leg outcomes at 1 year post-op. Group IC-2 (foraminal stenosis) showed VAS back and leg score improvement at one year post-op but did not demonstrate significant improvement in overall ODI outcome at any time point. The one year re-operation rate was 2% (1/40) for group IC-1 and 28% (5/18) for group IC-2. CONCLUSIONS: The initial results of the MIS Registry IC subgroup show a significant clinical improvement when the technique is employed to treat patients with lumbar disc herniation. The treatment of foraminal stenosis can lead to improved short-term clinical outcome but is associated with a high re-operation rate at 1 year post-op.

Validation and analysis of a multi-site MIS Prospective Registry through sub-analysis of an MIS TLIF Subgroup.

STUDY DESIGN: Retrospective analysis of multi-site, prospectively collected database. OBJECTIVE: To assess the validity and utility of a prospective spine registry by sub-analysis of patients treated with MIS TLIF. BACKGROUND: The MIS registry is a large-scale, multi-center series of prospectively collected clinical information on outcomes, complications, and adverse events for minimally invasive spine procedures for the treatment of degenerative lumbar conditions. METHODS: Analysis was performed on the MIS Prospective Registry database. A subgroup of patients treated by MIS TLIF technique was identified. Statistical analyses were performed on pre and post-operative data collected using validated health related quality of life outcome tools. Missing 1-year patient follow-up data was obtained through progressive correspondence modalities. RESULTS: Data analysis was performed on 98 MIS TLIF patients (56 female, 42 male) with a median age of 64.5 years (range 25-91 years) which were extracted from a total registry population of 478 patients. The one year follow-up rate was 87%. A total of 64 single-level, 23 two-level, 3 three-level, and 3 combined TLIFs staged with an MIS lateral procedure were included. The primary surgical indications were spondylolisthesis (27%), central stenosis (25%), foraminal stenosis (14%), post-laminectomy syndrome (14%) and degenerative scoliosis (6%). The peri-operative blood transfusion rate was 3%. Complications included intraoperative dural tear (n = 3), deep wound infection (n = 2), superficial dehiscence/cellulitis (n = 2). There was a 4% re-operation rate at the 1 year post-operative time point. Half of patients were discharged within 2 days (range 1-11 days, mean 2.97 days, median 2 days). All patients that were discharged on the first post-operative day (n = 14) underwent a single-level MIS TLIF procedure and had significantly lower pre-op disability index score than those discharged on POD 3-5 (43.7 ± 15.5 vs. 56.0 ± 18.3, p = 0.04). Average ODI scores in the subgroup of patients that had reached the one year postoperative time point were 46.5 pre-op (n = 46), and 26.2 at 1 year post-op (n = 40, p = 0.0001). There was significant improvement in VAS scores: pre-operative (back = 6.7, leg = 5.4, n = 46), and 1 year post-operative (back = 3.2, leg = 1.7, n = 40, p = 0.0001). Patients with pre-operative ODI scores greater than 50 demonstrated significant improvement starting at the 6 week post-operative time point (24 point improvement, n = 46, p < 0.001). A pre-operative ODI between 35-50 showed significant improvement starting at 3 months (15.5 point improvement, n = 29, p = 0.05). Patients with a pre-operative ODI score less than 35 had an initial period of increased disability with a trend towards significant improvement by 3 months post-op (n = 20). CONCLUSIONS: Initial findings of the MIS Prospective Registry show patients can be enrolled in a relatively short time period and patient based questionnaires can successfully be obtained through a combination of clinic follow-up appointments and remote correspondence. Outcomes of the MIS Registry MIS TLIF subgroup were consistent with previously published MIS TLIF studies. Sub-analysis of data collected through level-specific patient diagnosis and treatment modalities permits outcome analysis of a wide breadth of spinal conditions and interventions.

Closed suction irrigation for the treatment of postoperative wound infections following posterior spinal fusion and instrumentation.

STUDY DESIGN: Retrospective review of clinical cases. OBJECTIVE: This study describes the success rate of closed suction irrigation system (CSIS) in the treatment of post operative spinal infections. SUMMARY OF BACKGROUND DATA: Given the widening use of spinal instrumentation, the management of related postoperative deep wound infections has become increasingly important. In the literature, there have been reports of several treatment methods yet no firmly established protocol for management of postoperative deep wound infections exists. The goal of this study was to determine the effectiveness of our protocol employing (CSIS) in the treatment of postoperative deep wound infections. METHODS: A retrospective record review of 500 posterior instrumented fusions between 1990 and 2002. Twenty-eight consecutive infections (5%) were diagnosed and treated by a standardized treatment protocol of Incision and Drainage, and CSIS. Cultures were obtained, wounds closed primarily, and appropriate intravenous antibiotic treatments initiated. For statistical evaluation, patients were assigned a risk factor (RF) described by Levi et al (J Neurosurg. 1997;86:975-980). Point values were assigned to medical comorbidities that may contribute to postoperative infection risk; higher RF values indicate an increased risk. RESULTS: Twenty-one acute and 7 late (>6 months) infections were followed for 22.3 months (1-86 months), post-CSIS treatment. Twenty-one (75%) resolved without recurrence with one CSIS treatment. Seven acute infections (25%) required a second course of treatment. Hospitalization for the index procedure averaged 15.4 days; 28.9 days for reinfections. No patient with an acute infection required implant removal. The reinfection group had higher blood loss, more levels fused, and longer hospitalization. The reinfection group was comprised entirely of pediatric patients. CONCLUSION: No correlation was found between RF values and greater risk of recurrent infection. Removal of implants is unnecessary in acute infections, provided the infection does not return. CSIS is an effective method for treatment of postoperative wound infections following instrumented spinal fusion avoiding the need for secondary closure.

Anterior exposure of the spine for removal of lumbar interbody devices and implants.

STUDY DESIGN: A retrospective review of a consecutive series of 14 patients operated on between March 1998 and April 2005. OBJECTIVES: To report on patients having undergone revision lumbar surgery anteriorly to remove interbody devices placed anteriorly or posteriorly and to determine the incidence of associated complications. SUMMARY OF BACKGROUND DATA: The popularity of interbody lumbar surgery has grown in recent years. Consequently, the number of anterior revision procedures has increased. The risks associated with anterior approach for revision procedures and interbody device removal, in particular, have not been reported. METHODS: The results of 13 consecutive patients who had removal of interbody devices through an anterior approach and 1 patient with removal of anterior fixation (7 males, 7 females; mean age 43 years) were reviewed. The procedure during which the original implant was placed was a posterior lumbar interbody fusion in 4, transforaminal lumbar interbody fusion in 5, and anterior lumbar interbody fusion in 5 patients. Four attending spine surgeons performed the procedures with the assistance of 4 experienced access surgeons. RESULTS: Ten of 14 (71%) patients had complications associated with anterior exposure of revision surgery. Vascular injury is the most common complication (57%). Vascular complications occurred in 100% (4/4) of the revisions of previous posterior lumbar interbody fusions and 80% (4/5) of previous anterior lumbar interbody fusions. The complication rate at L4-5 and L5-S1 was 89% and 40%, respectively. There was 1 postoperative mortality. CONCLUSIONS: Anterior removal of lumbar interbody devices placed anteriorly or posteriorly has a high incidence of complication. Average blood loss and hospital stay are increased with revision anterior surgery. The vascular complication rate is 2-fold higher at L4-L5 level compared to L5-S1.