Quantification of needle angles for lumbar medial branch denervation targeting the posterior half of the superior articular process: an osteological study.

BACKGROUND: Lumbar medial branch radiofrequency ablation (RFA) is a common intervention to manage chronic axial low back pain originating from the facet joints. A more parasagittal approach targeting the posterior half of the lateral neck of superior articular process (SAP) was previously proposed. However, specific needle angles to achieve parallel placement at this target site have not been investigated. OBJECTIVE: To quantify and compare the needle angles, on posterior and lateral views, to achieve parallel placement of electrodes along the medial branch at the posterior half of the lateral neck of SAP at each lumbar vertebral level (L1-L5) and sacrum. DESIGN: Osteological Study. METHODS: Twelve disarticulated lumbosacral spines (n = 72 individual bones) were used in this study. Needles were placed along the periosteum of the posterior half of the lateral neck of SAP, bilaterally and photographed. Mean needle angles for each vertebral level (L1-L5) and sacrum were quantified, and statistical differences were analyzed. RESULTS: The posterior view provided the degrees of lateral displacement from the parasagittal plane (abduction angle), while the lateral view provided the degrees of declination (cranial-to-caudal angle) of the needle. Mean needle angles at each level varied, ranging from 5.63 ± 5.76° to 14.50 ± 14.24° (abduction angle, posterior view) and 40.17 ± 7.32° to 64.10 ± 9.73° (cranial-to-caudal angle, lateral view). In posterior view, a < 10-degree needle angle interval was most frequently identified (57.0% of needle placements). In lateral view, the 40-50-degree (L1-L2), 50-60-degree (L3-L5), and 60-70-degree (sacrum) needle angle intervals occurred most frequently (54.2%, 50.0%, and 41.7% of needle placements, respectively). CONCLUSIONS: Targeting the posterior half of the lateral neck of SAP required <10-degree angulation from parasagittal plane in majority of cases. However, variability of needle angles suggests a standard "one-size-fits-all" approach may not be the optimal technique.

Low back pain-related healthcare utilization following intraosseous basivertebral nerve radiofrequency ablation: a pooled analysis from three prospective clinical trials.

BACKGROUND: The effectiveness and safety of intraosseous basivertebral nerve ablation (BVNA) for treating vertebrogenic pain is established, but low back pain-related healthcare utilization (LBPr-HU) following BVNA continues to be defined. METHODS: LBPr-HU data were pooled from 3 prospective studies. LBPr-HU categories of interest included non-invasive conservative care, opioid utilization, lumbosacral spinal injection (LSI), lumbosacral radiofrequency ablation (LRFA), and lumbosacral spinal surgery. Pre- and post-BVNA LBPr-HU were compared at both 1- and 5-years using McNemar's test for proportions and paired t-tests for means. RESULTS: Two hundred forty-seven patients received BVNA and had 1-year follow-up; 205 had long-term follow-up (mean of 5.3 ± 1.33 years). Twenty-seven percent fewer participants initiated conservative care in the year post-BVNA compared to the year preceding BVNA (P < .001; 95% CI 19.8-34.5). Of 77/247 participants taking opioids at baseline, 40.3% and 61.7% fewer were taking them at one-year and 5.3 ± 1.33 years post-BVNA, respectively (P < .001). Of participants receiving LSIs in the year preceding BVNA, 81.2% fewer received LSI(s) in the year post-BVNA (P < .001; 95% CI 70.7-90.7); a 76.4% reduction in LSIs was maintained through a mean of 5.3 ± 1.33 years post-BVNA. LRFA rates were 1.6% at 1-year post-BVNA and 8.3% at 5.3 ± 1.33 years post-BVNA. Lumbar fusion surgery was 0.8% at 1-year post-BVNA and 6.5% at 5.3 ± 1.33 years post-BVNA. CONCLUSIONS: In this aggregate analysis of patients with vertebrogenic pain, utilization of conservative care, opioids, LSIs, and LRFA were substantially reduced through 5 years post-BVNA compared to baseline. Lumbar fusion rates were less than half the published value at 5 years in similar populations.

Retrospective Study to Compare the Effectiveness of Minimally Invasive Microscopic Unilateral Laminotomy with Microscopic Bilateral Laminotomy for Bilateral Decompression in the Early Postoperative Period in 142 Patients with Single-Level Lumbar Spinal Stenosis.

BACKGROUND We aimed to compare the effectiveness of microscopic unilateral laminotomy for bilateral decompression (ULBD) and microscopic bilateral laminotomy for bilateral decompression (BLBD) in the early postoperative period among patients with single-level lumbar spinal stenosis (LSS). MATERIAL AND METHODS A retrospective cohort study was conducted on patients with LSS who underwent ULBD or BLBD between January 2020 and December 2023, including 94 patients who underwent ULBD and 58 who underwent BLBD. Patient demographics, comorbidities, smoking status, and data related to LSS were reviewed. Preoperative and postoperative assessments on day 10 included back pain visual analog scale (VAS), walking distance, and Odom criteria. Disability was evaluated using the self-assessment Oswestry Disability Index (ODI) preoperatively and on day 30. Additionally, wound infection, postoperative modified MacNab criteria, and pain (back, leg, and hip) were recorded. RESULTS Age and sex were similar in the 2 groups. Both surgeries significantly reduced low back pain, increased walking distance, and improved Odom category on day 10, compared with baseline (P<0.001 for all). A significant decrease in 30-day ODI, compared with baseline, was observed in both groups (P<0.001 for both). The ULBD group had a significantly higher percentage of patients with wound infection (P=0.014); however, the ODI score among ULBD recipients was significantly lower (better) on day 30 (P=0.047). CONCLUSIONS ULBD may represent a less invasive, more effective, and safer surgical alternative than BLBD and classical laminectomy in patients with single-level LSS, but precautions are essential concerning wound infection.

Predictive Factors for Residual Low Back Pain Following Percutaneous Endoscopic Lumbar Discectomy in Patients with Lumbar Disc Herniation.

BACKGROUND Percutaneous endoscopic lumbar discectomy (PELD) is a mature and popular surgery for treatment of lumbar disc herniation (LDH). The main objective of our study was to identify risk factors for residual low back pain after PELD and to improve postoperative management. MATERIAL AND METHODS We retrospectively analyzed the clinical and imaging data of 251 patients who underwent PELD for LDH. We defined residual LBP as visual analog scale (VAS) score for LBP ≥3 at 2 years postoperatively, and severe LBP was defined as VAS for LBP ≥7.5. The clinical and imaging data were analyzed by comparing patients with VAS scores ≥3 and <3, and univariate analysis and multivariable logistic regression analysis were applied to predict the risk factors for residual LBP. RESULTS There were 56 (22.3%) patients with LBP VAS ≥3 at 2 years postoperatively. Multivariable logistic regression analysis demonstrated that severe baseline VAS for LBP (P<0.001), MCs type I (P=0.006), and severe fatty infiltration of the paravertebral muscles (P<0.001) were independent risk factors for residual LBP after PELD. CONCLUSIONS In patients with LDH, MCs type I, severe baseline LBP, and fatty infiltration of the paravertebral muscles were predictive factors for residual LBP after PELD. Our study suggests that spine surgeons should pay more attention to these imaging parameters, which may be a helpful indicator for the choice of surgical modality.

Mitigating Factors in L4 and L5 Medial Branch Motor Stimulation During Radiofrequency Ablation.

PURPOSE OF REVIEW: Radiofrequency ablation (RFA) is a minimally invasive procedure for facet joint pain. The targets for the procedure are the medial branches of the dorsal spinal nerves which innervate the facet joints. Before RFA, patients undergo diagnostic meal branch blocks to ensure appropriate pain relief and confirm the utility of proceeding to RFA. The success of RFA relies heavily on procedural technique and accurate placement near the medial branch. RECENT FINDINGS: Motor testing is utilized in the lumbar region to assess the response of the multifidus and ensure proper placement of the RFA probe to prevent inadvertent damage to surrounding spinal anatomy. However, relying on motor responses in this area presents challenges given the frequency of lack of muscle twitching. Factors contributing to limited muscle twitch responses include muscle atrophy, excessive lordosis, facet arthropathy, local anesthetic use before ablation, and previous surgical neurotomy. These complexities highlight the challenges in ensuring precise motor stimulation during RFA. Despite these obstacles, accurate anatomical placement remains crucial. For RFA cases that prove challenging, relying on anatomical placement can be adequate to proceed with the procedure. Bridging knowledge gaps is vital for standardized practices and safer procedures. Further research is necessary to refine techniques, understand patient-specific factors, and enhance the efficacy of RFA in managing chronic lumbar facet joint pain.

Systematic Review and Meta-Analysis of the Effectiveness of Radiofrequency Ablation of the Sacroiliac Joint.

PURPOSE OF REVIEW: To evaluate the effectiveness of radiofrequency neurotomy in managing sacroiliac joint pain utilizing a systematic review with meta-analysis of randomized controlled trials (RCTs) and observational studies. RECENT FINDINGS: The prevalence of sacroiliac joint pain is estimated at around 25% of low back pain cases, and its diagnosis lacks a gold standard. Treatments include exercise therapy, injections, ablation, and fusion, with variable effectiveness. COVID-19 altered utilization patterns of interventions, including sacroiliac joint procedures, and the evidence for these interventions remains inconclusive. Recently, Medicare has issued its local coverage determinations (LCDs) in the United States, which provides noncoverage of sacroiliac joint radiofrequency neurotomy. Additionally, a recent systematic review of sacroiliac joint injections showed Level III or fair evidence. The sacroiliac joint, a critical axial joint linking the spine and pelvis, contributes to low back pain. Its complex innervation pattern varies among individuals. Sacroiliac joint dysfunction, causing pain and stiffness, arises from diverse factors.The present systematic review and meta-analysis aimed to evaluate radiofrequency neurotomy's effectiveness for sacroiliac joint pain management by applying rigorous methodology, considering both RCTs and observational studies. Despite methodological disparities, the evidence from this review, supported by changes in pain scores and functional improvement, suggests Level III evidence with fair recommendation for radiofrequency neurotomy as a treatment option. The review's strengths include its comprehensive approach and quality assessment. However, limitations persist, including variations in criteria and technical factors, underscoring the need for further high-quality studies in real-world scenarios.

Percutaneous radiofrequency ablation and endoscopic neurotomy for lumbar facet joint syndrome: are they good enough?

OBJECTIVE: Lumbar facet joint (LFJ) syndrome is one of the common causes of low back pain (LBP). There are different views on percutaneous and endoscopic radiofrequency. The purpose of this systematic review and meta-analysis is to explore the therapeutic effect of radiofrequency ablation on LBP originating from LFJ and compare the therapeutic effect of percutaneous radiofrequency ablation and endoscopic neurotomy. METHODS: We included randomized controlled trials which compared the efficiency of percutaneous radiofrequency ablation and conservative treatment (sham procedures, facet joint injection, physiotherapy, exercise, or oral medication) or compared the efficiency of percutaneous radiofrequency ablation and endoscopic neurotomy for LFJ syndrome. We searched in PubMed and Web of Science from inception to March 27, 2023. Meta-analysis was performed using RevMan 5.4 software. RESULTS: A total of 11 randomized controlled trials were included. Among them, nine studies were used for evaluating efficiency of percutaneous radiofrequency ablation, and two studies were used for evaluating efficiency of endoscopic neurotomy. Pooled data from two studies reporting outcomes at 1 year did not show a benefit from facet joint denervation by comparing the percutaneous radiofrequency ablation and conservative treatment (standardized mean difference (SMD) = -0.87, 95% confidence interval (CI) [-2.10, 0.37], P = 0.17). There was no significant difference between percutaneous radiofrequency ablation and endoscopic neurotomy at 1-month follow-up (mean difference (MD) = -0.13, 95%CI [-0.18, -0.44], P = 0.41). At 12-month follow-up the pain relief in the endoscopic neurotomy was significantly better than that in the percutaneous radiofrequency ablation group (MD = 1.98, 95%CI [1.60, 2.36], P < 0 .0001). CONCLUSION: The LBP was significantly relieved shortly after percutaneous radiofrequency ablation. Compared with percutaneous radiofrequency ablation, endoscopic neurotomy seems to have a longer effect. A longer follow-up period is needed to confirm its effectiveness.

Effect of revision sacroiliac joint fusion on unresolved pain and disability: a retrospective cohort study.

PURPOSE: The sacroiliac (SI) joint is recognized as a source of low back pain in 15-30% of patients. Though randomized controlled trials have shown clinical improvement following SI joint fusion in 83.1% of patients, revision rates of 2.9% within 2 years have been reported. There is a paucity of literature reviewing this small yet significant population of patients requiring revision surgery. METHODS: Following IRB approval, retrospective review of patients, who underwent a revision SI joint fusion from 2009 to 2021 was completed. Patient-reported outcomes were measured before and at each clinic visit after surgery with visual analoge scale (VAS) for back pain and Oswestry Disability Index (ODI). Patient characteristics (chronic opiate use and prior lumbar fusion) and surgical factors (operative approach, type/number of implants and use of bone graft) were recorded. Patient-reported outcomes were evaluated with Paired t and Wilcoxon signed rank tests. Univariate and multivariate logistic regression determined if patients met the minimally clinical important differences (MCID) for VAS-back pain and ODI scores at 1 year. RESULTS: Fifty-two patients (77% female) with an average age of 49.1 (SD ± 11.1) years met inclusion criteria. Forty-four had single sided revisions and eight bilateral revisions. At 1 year follow-up there was no significant improvement in VAS-Back (p = 0.06) or ODI (p = 0.06). Patients with chronic opioid use were 8.5 times less likely to achieve the MDC for ODI scores (OR 0.118, p = 0.029). There was no difference in outcomes when comparing the different surgical approaches (p = 0.41). CONCLUSION: Our study demonstrates patients undergoing revision surgery have moderate improvement in low back pain, however, few have complete resolution of their symptoms. Specific patient factors, such as chronic opiate use and female sex may decrease the expected improvement in patient-reported outcomes following surgery. Failure to obtain relief may be due to incorrect indications, lack of biologic fusion and/or presence of co-pathologies. Further clinical examination and consistent long-term follow-up, clarify the role revision surgery plays in long-term patient outcomes.

A clinicopathological study of low back pain due to middle cluneal nerve entrapment: case series.

PURPOSE: The middle cluneal nerve (MCN) is a pure sensory nerve around the middle buttock. Its entrapment between the iliac crest and the long posterior sacroiliac ligament elicits low back pain (LBP) that can be treated by MCN neurolysis or neurectomy. Because few studies examined the pathology of MCN entrapment (MCN-E) we subjected 7 neurectomized specimens from 6 LBP patients to pathologic study. METHODS: We present 6 consecutive patients (7 sides) with intractable LBP who underwent successful MCN neurectomy. Their symptom duration ranged from 6 to 96 months (average 47.3 months); the follow-up period ranged from 6 to 17 months (average 11.7 months). The surgical outcomes were evaluated using the numerical rating scale (NRS) for LBP and the Roland-Morris Disability Questionnaire (RDQ) score. The resected MCNs underwent neuropathological analysis. RESULTS: Postoperatively, all 6 patients reported immediate LBP amelioration; their NRS and RDQ scores were improved significantly. Pathological study of the 7 resected nerves showed that the myelinated fiber density was decreased in 6 nerves; we observed marked enlargement (n = 5), perineurial thickening and disruption (n = 6), intrafascicular fibrous changes (n = 5), myelinated fibers separated by fibrous cells under the perineurium (n = 4), and Renaut bodies (n = 3). The 7th nerve appeared normal with respect to the density and size of the myelinated fibers, however, the perineurium was slightly thickened. CONCLUSION: We present pathological evidence at the MCN compression site of 7 nerves from 6 patients whose LBP was alleviated by MCN neurectomy, indicating that MCN entrapment can elicit LBP.

Short-segment spinal fusion for chronic low back pain with bone marrow edema adjacent to the vertebral endplate in adult spinal deformity.

PURPOSE: Corrective long spinal fusion is a widely accepted surgical method for patients with adult spinal deformities. However, instrumented long fusion is associated with a significant risk of complications. Therefore, we aimed to assess the success of short-segment spinal fusion, particularly for bone marrow edema (BME) adjacent to the vertebral endplate, in patients with low back pain (LBP) and spinal deformity. METHODS: A prospective study was performed at multiple hospitals wherein we monitored patients with spinal deformities and accompanying LBP. Patients aged ≥ 50 years with a minimum LBP severity score of 40 mm on the visual analog scale (VAS) were included in the study. We also included patients with lumbar BME on magnetic resonance imaging. Short spinal fusion was performed on segments with BME. Clinical evaluations of LBP on VAS and Oswestry Disability Index (ODI), and radiological parameters for sagittal vertical axis (SVA), pelvic incidence (PI), lumbar lordosis (LL) and pelvic tilt (PT) were carried out. RESULTS: Overall, 35 patients (22 men and 13 women), with a mean age of 66.7 years and a mean follow-up period of 32 months, were included in the study. The mean VAS and ODI scores were 72.4 mm and 49.0% before surgery and 25.5 mm and 29.9% at the final follow-up, respectively; these parameters significantly improved after surgery. The SVA, PI-LL, and PT scores were 70.1 mm, 20.9°, and 22.8° before surgery and 85.4 mm, 13.8°, and 22.7° at the final follow-up, respectively. The spinal alignment parameters did not change significantly after surgery. CONCLUSIONS: Short-segment spinal fusion is effective for treating LBP and spinal deformity with BME adjacent to the vertebral endplate without spinal correction.

Is unilateral-approach full-endoscopic lumbar fusion effective for single-level lumbar spondylolisthesis with bilateral symptoms? A preliminary report of 43 CT analysis.

PURPOSE: To investigate the clinical results and radiological parameters changes after unilateral-approach endoscopic lumbar interbody fusion (Endo-LIF) for lumbar spondylolisthesis with bilateral symptoms. METHODS: 43 single-level lumbar spondylolisthesis patients with bilateral lower limb symptoms were included from June 2020 to May 2022. All patients underwent unilateral-approach Endo-LIF and postoperative computed tomography. Radiological parameters including disk height (DH), degree of upper vertebral slip (DUVS), and foramen intervertebral parameters including bilateral foraminal height (FH), contralateral foraminal areas (FA) were evaluated. The clinical outcomes including low back pain and bilateral leg pain were evaluated using Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI) before and after surgery. RESULTS: All cases were successfully completed surgery and followed for average 15.16 ± 5.2 months. DH (44% ± 11%) and DUVS were significantly improvement postoperatively compared with preoperatively (p < 0.05). Statistically significant increases in bilateral FH (25% ± 11% on the surgical side, 17% ± 8% on the contralateral side) and contralateral FA (26% ± 6%) were observed (p < 0.05). The VAS and the ODI scores were significantly decreased in comparison with the preoperative scores (p < 0.05). CONCLUSION: Unilateral-approach with contralateral indirect decompression in Endo-LIF can acquire satisfactory clinical outcomes. Therefore, unilateral-approach Endo-LIF may be a promising option for lumbar spondylolisthesis with bilateral symptoms.

Prolonged opioid use after single-level lumbar spinal fusion surgery in a Belgian population: a multicentric observational study.

PURPOSE: Lumbar spinal fusion surgeries are increasingly being performed in spinal degenerative disease, often accompanied by perioperative opioid prescriptions. The aim of this study is to analyze prolonged postoperative opioid use following a standardized opioid prescription after single-level lumbar spinal fusion surgery in a Belgian population. METHODS: This prospective, multicentric observational study included patients undergoing single-level lumbar fusion surgery for degenerative disease. A standardized postoperative opioid protocol (Targinact 2 × 10 mg/5 mg, Paracetamol 4 × 1 g and Ibuprofen 3 × 600 mg) was applied uniformly. Prolonged opioid use was defined as continued opioid use six months after surgery. Patient data were collected using the Back-App®. RESULTS: Among 198 participants, 32.8% continued opioid use six months post-surgery, with 8% utilizing strong opioids. Prolonged opioid use correlated with lower pre-operative back pain. Patients with prolonged opioid use and strong opioid use at six months show less improvement in disability compared to patients without prolonged opioid use. Moreover, patients with prolonged strong opioid use tend to have lesser improvement of the low back pain. The odds for prolonged opioid use decrease with the increase of the improvement in ODI. CONCLUSION: 1 in 3 patients undergoing single-level lumbar spinal fusion surgery is at risk for prolonged opioid use. The study underscores the importance of tailored pain management strategies, particularly given the rising prevalence of spinal fusion surgeries. The association between pre-operative low back pain, post-operative improvement in functionality (ODI), and prolonged opioid use emphasizes the need for judicious opioid prescribing practices and highlights the role of functional outcomes in treatment goals.

Development and validation of a nomogram to predict the risk of residual low back pain after tubular microdiskectomy of lumbar disk herniation.

OBJECTIVE: Tubular microdiskectomy (tMD) is one of the most commonly used for treating lumbar disk herniation. However, there still patients still complain of persistent postoperative residual low back pain (rLBP) postoperatively. This study attempts to develop a nomogram to predict the risk of rLBP after tMD. METHODS: The patients were divided into non-rLBP (LBP VAS score < 2) and rLBP (LBP VAS score ≥ 2) group. The correlation between rLBP and these factors were analyzed by multivariate logistic analysis. Then, a nomogram prediction model of rLBP was developed based on the risk factors screened by multivariate analysis. The samples in the model are randomly divided into training and validation sets in a 7:3 ratio. The Receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the diskrimination, calibration and clinical value of the model, respectively. RESULTS: A total of 14.3% (47/329) of patients have persistent rLBP. The multivariate analysis suggests that higher preoperative LBP visual analog scale (VAS) score, lower facet orientation (FO), grade 2-3 facet joint degeneration (FJD) and moderate-severe multifidus fat atrophy (MFA) are risk factors for postoperative rLBP. In the training and validation sets, the ROC curves, calibration curves, and DCAs suggested the good diskrimination, predictive accuracy between the predicted probability and actual probability, and clinical value of the model, respectively. CONCLUSION: This nomogram including preoperative LBP VAS score, FO, FJD and MFA can serve a promising prediction model, which will provide a reference for clinicians to predict the rLBP after tMD.

Association between cup orientation and low back pain after total hip arthroplasty in patients with osteonecrosis of the femoral head.

BACKGROUND: Postoperative low back pain (LBP) following total hip arthroplasty (THA) is classified as secondary hip-spine syndrome. The purpose of this study was to explore the correlations between cup orientation of THA and postoperative LBP in patients with osteonecrosis of the femoral head (ONFH). METHODS: A retrospective cohort study included 364 ONFH patients who underwent bilateral THA between January 2011 and December 2020. Among them, 53 patients (14.6%) experienced postoperative LBP at the end of follow-up and were designated as pain group (PG). A control group (CG) consisting of 106 patients with similar age, sex, and body mass index (BMI) to those in the PG was selected. Postoperative LBP in the PG was assessed using the visual analogue scale (VAS). Demographic data, clinical information, and radiographic criteria were evaluated as potential predictors of LBP. RESULTS: Patients in PG (mean age, 47.3 years [range, 27 to 75 years]; 42 [79%] male) had a mean VAS score of 4.6 (range, 1 to 9) compared with 0 for the patients in CG (mean age, 47.6 years [range, 19 to 77 years]; 84 [79%] male). There were no significant differences in clinical data between the two groups (p > 0.05). Preoperative radiographic variables also showed no significant differences between the PG and CG (p > 0.05). However, the postoperative inclination, anteversion, and standing ante-inclination (AI) were significantly lower in the PG compared to the CG, whereas the sitting and standing sacral slope (SS) were significantly higher (p < 0.05). Moreover, the variations in standing AI, standing and sitting pelvic tilt (PT) were significantly lower in the PG compared to the CG, while the variations in standing and sitting SS and lumbar lordosis (LL) were significantly higher (p < 0.05). The variation in standing AI in the PG showed a significantly correlation with the variation of standing SS, standing PT, and LL (p < 0.05). CONCLUSION: Postoperative LBP in ONFH patients after bilateral THA is significantly associated with the intraoperative cup orientation. The variation in standing AI is correlated with the variations in standing SS, standing PT, and LL, potentially contributing to the development of postoperative LBP.

Spinal fusion surgery use among adults with low back pain enrolled in a digital musculoskeletal program: an observational study.

OBJECTIVES: To compare 12-month spinal fusion surgery rates in the setting of low back pain among digital musculoskeletal (MSK) program participants versus a comparison cohort who only received usual care. STUDY DESIGN: Retrospective cohort study with propensity score matched comparison cohort using commercial medical claims data representing over 100 million commercially insured lives. METHODS: All study subjects experienced low back pain between January 2020 and December 2021. Digital MSK participants enrolled in the digital MSK low back program between January 2020 and December 2021. Non-participants had low back pain related physical therapy (PT) between January 2020 and December 2021. Digital MSK participants were matched to non-participants with similar demographics, comorbidities and baseline MSK-related medical care use. Spinal fusion surgery rates at 12 months post participation were compared. RESULTS: Compared to non-participants, digital MSK participants had lower rates of spinal fusion surgery in the post-period (0.7% versus 1.6%; p < 0.001). Additionally, in the augmented inverse probability weighting (AIPW) model, digital MSK participants were found to have decreased odds of undergoing spinal fusion surgery (adjusted odds ratio: 0.64, 95% CI: 0.51-0.81). CONCLUSIONS: This study provides evidence that participation in a digital MSK program is associated with a lower rate of spinal fusion surgery.

Middle cluneal nerve entrapment sites in the surgical field.

INTRODUCTION: Middle cluneal nerve (MCN) entrapment around the sacroiliac joint elicits low back pain (LBP). For surgical decompression to be successful, the course of the MCN must be known. We retrospectively studied the MCN course in 15 patients who had undergone MCN neurolysis. METHODS: Enrolled in this retrospective study were 15 patients (18 sides). We inspected their surgical records and videos to determine the course of the entrapped MCN. The area between the posterior superior- and the posterior inferior iliac spine was divided into areas A-D from the rostral side. The MCN transit points were identified at the midline and the lateral edge connecting the posterior superior- and posterior inferior iliac spine. Before and 6 months after surgery, the patients recorded the degree of LBP on the numerical rating scale and the Roland-Morris Disability Questionnaire. RESULTS: We decompressed 24 MCNs. The mean number was 1.3 nerves per patient (range 1-2). The MCN course was oblique in the cranio-caudal direction; the nerve tended to be observed in areas C and D. In six patients (40%), we detected two MCN branches, they were in the same area and adjacent. Postoperatively, LBP was improved significantly in all patients. CONCLUSION: Between the posterior superior- and the posterior inferior iliac spine, the MCN ran obliquely in the cranio-caudal direction; it was prominent in areas on the caudal side. In six (40%) patients, we decompressed two adjacent MCNs. Our findings are useful for MCN decompression surgery.

Identification and decompression of superior cluneal nerve implicated in low back pain.

INTRODUCTION: Low back pain (LBP) can be attributable to entrapment of the superior cluneal nerve (SCN) around the iliac crest. Surgical decompression is a useful treatment; however, finding all entrapped SCNs involved in patients with LBP can be difficult. We performed a retrospective study to help identify entrapped SCNs in the narrow surgical field. METHODS: We enrolled 20 LBP patient (22 sides) with SCN entrapment. They were 9 males and 11 females; their mean age was 72.5 years. We developed a 3-step procedure for successful SCN decompression surgery. In step 1, the thoracolumbar fascia is exposed and the SCN penetrating the fascia is released. In step 2, the fascia is opened and the SCN is released. In step 3, the fascia above the iliac crest is opened and the SCN is released. RESULTS: We successfully released 66 nerves; the average was 3.0 ± 0.8 (1-4) per patient. Step 1 detected 18 nerves (27.3%), step 2 identified 35 (53.0%), and in step 3, 13 (19.7%) were recognized. By tracing the thin nerves branching off the SCN, we found 7 nerves (10.6%). We performed 22 operations; step 1 identified 16 SCNs (72.7%), step 2 identified 21 (95.5%), and step 3 found 12 nerves (54.5%). CONCLUSIONS: The SCN is most readily identified upon opening of the thoracolumbar fascia. To identify as many SCN branches as possible, our 3-step method may be useful.

The Gluteus-Score-7 Predicts the Likelihood of Both Clinical Success and Failure Following Surgical Repair of the Hip Gluteus Medius and/or Minimus.

PURPOSE: To identify patient preoperative history, examination, and imaging characteristics that increase the risk of postoperative failure of gluteus medius/minimus repair, and to develop a decision-making aid predictive of clinical outcomes for patients undergoing gluteus medius/minimus repair. METHODS: Patients from 2012 to 2020 at a single institution undergoing gluteus medius/minimus repair with minimum 2-year follow-up were identified. MRIs were graded according to the "three-grade" classification system: grade 1: partial-thickness tear, grade 2: full-thickness tears with <2 cm of retraction, grade 3: full-thickness tears with ≥2 cm retraction. Failure was defined as undergoing revision within 2 years postoperatively or not achieving both a cohort-calculated minimal clinically important difference (MCID) and responding "no" to patient acceptable symptom state (PASS). Inversely, success was defined as reaching both an MCID and responding "yes" to PASS. Predictors of failure were verified on logistic regression and a predictive scoring model, the Gluteus-Score-7, was generated to guide treatment-decision making. RESULTS: In total, 30 of 142 patients (21.1%) were clinical failures at mean ± SD follow-up of 27.0 ± 5.2 months. Preoperative smoking (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.0-8.4; P = .041), lower back pain (OR, 2.8; 95% CI, 1.1-7.3; P = .038), presence of a limp or Trendelenburg gait (OR, 3.8; 95% CI, 1.5-10.2; P = .006), history of psychiatric diagnosis (OR, 3.7; 95% CI, 1.3-10.8; P = .014), and increased MRI classification grades (P ≤ .042) were independent predictors of failure. The Gluteus-Score-7 was generated with each history/examination predictor assigned 1 point and MRI classes assigned corresponding 1-3 points (min 1, max 7 score). A score of ≥4/7 points was associated with risk of failure and a score ≤2/7 points was associated with clinical success. CONCLUSIONS: Independent risk factors for revision or not achieving either MCID or PASS after gluteus medius and/or minimus tendon repair include smoking, preoperative lower back pain, psychiatric history, Trendelenburg gait, and full-thickness tears, especially tears with ≥2 cm retraction. The Gluteus-Score-7 tool incorporating these factors can identify patients at risk of both surgical treatment failure and success, which may be useful for clinical decision-making. LEVEL OF EVIDENCE: Level IV, prognostic case series.

How Do Spinal Parameters Change in Patients Who Have Improvement of Low Back Pain After Total Hip Arthroplasty? A Propensity Score-Matched Cohort Study.

BACKGROUND: Many studies have demonstrated that low back pain (LBP) improves after total hip arthroplasty (THA). However, the mechanism underlying this improvement remains unclear. We aimed to investigate changes in the spinal parameters of patients who had LBP improvement after THA to elucidate the mechanism of LBP improvement. METHODS: We included 261 patients who underwent primary THA between December 2015 and June 2021 and had a preoperative visual analog scale score of ≥ 2 for LBP. The patients were classified into the LBP-improved or LBP-continued groups based on the visual analog scale for LBP at 1 year after THA. Preoperative and postoperative changes in the coronal and sagittal spinal parameters were compared between the 2 groups after propensity score matching for age, sex, body mass index, and preoperative spinal parameters. RESULTS: A total of 161 patients (61.7%) were classified into the LBP-improved group. After 85 patients in both groups were matched, the LBP-improved group showed significant differences in spinal parameter changes, which were a higher lumbar lordosis (LL) (P = .04) and lower sagittal vertical axis (SVA) (P = .02) and pelvic incidence (PI) minus LL (PI-LL) (P = .01) postoperatively, whereas the LBP-continued group showed worsened changes in LL and SVA and PI-LL mismatch. CONCLUSION: Patients who had LBP improvement after THA had significant differences in spinal parameter changes in LL, SVA, and PI-LL. These spinal parameters may be the key factors in the mechanism of LBP improvement after THA.

Does vacuum phenomenon at non-fused discs affect the postoperative course after transforaminal lumbar interbody fusion in patients showing a positive value of difference in lumbar lordosis?

INTRODUCTION: Preoperative difference in lumbar lordosis (DiLL) was associated with surgical outcomes after single-level transforaminal lumbar interbody fusion (TLIF). Patients with DiLL>0 (DiLL (+)) tended to show worse clinical outcomes and postoperative greater restoration of lumbar lordosis (LL). However, some patients with DiLL (+) showed relatively good outcomes and no postoperative LL restration. This study aimed to elucidate whether the lumbar intervertebral disc vacuum phenomenon (VP) influences clinical course after single-level TLIF in patients with DiLL (+) and DiLL (-). METHODS: Patients with lumbar spinal stenosis and degenerative spondylolisthesis treated with single-level TLIF were included. Pre- and postoperative LL were measured, and postoperative LL improvement was calculated. Preoperative DiLL was calculated as preoperative supine LL minus standing LL. Severity of VP at the non-fused discs (SVP (non-FS)) was evaluated using preoperative reconstructed computed tomography imaging. Clinical outcomes were assessed using the Oswestry disability index, visual analogue scale (VAS; low back pain (LBP), lower-extremity pain, numbness, and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Patients were stratified by the median preoperative SVP (non-FS) score into severe and mild VP groups in patients with DiLL (+) or DiLL (-), and their surgical outcomes were compared. RESULTS: Overall, 89 patients were included. In patients with DiLL (+) (n = 37), patients with severe VP showed worse clinical outcomes, particulary for LBP and DiLL (+) patients with mild VP showed greater LL improvement (6.5° ± 10.0°). In patients with DiLL(-) (n = 52), patients with severe VP showed worse clinical outcomes, particularly for LBP and no differences in preoperative, postoperative, and improvement of LL were observed between two groups. CONCLUSION: Patients with DiLL (+) and DiLL (-) showed different clinical courses depending on VP severity at the non-fused discs after single-level TLIF.