Basivertebral nerve ablation with concurrent lumbar laminotomy.

Lumbar radiculopathy due to impingement of nerve roots from facet hypertrophy and/or disc herniation can often coincide with vertebrogenic low back pain. This is demonstrated on MRI with foraminal stenosis and Modic changes. We examine the potential of using a combination of basivertebral nerve ablation (BVNA) and lumbar laminotomy as an alternative to traditional spinal fusion in specific patient populations. This unique combination of surgical techniques has not been previously reported in the medical literature. We report a man in his late 30s with chronic low back pain and lumbar radiculopathy, treated with BVNA and concurrent laminotomy. The patient reported progressive improvements in his mobility and pain over the next 2 years. We discuss the advantages of using this technique for lumbar radiculopathy and Modic changes compared with conventional surgical modalities.

Efficacy of Lateral View Needle Placement for Sacroiliac Joint Injections.

Introduction: Sacroiliac joint (SIJ) pathology is typically diagnosed and treated with fluoroscopy-guided intraarticular injections. Most practitioners use only an anteroposterior (AP) or oblique view. Although injection into the periarticular space may yield adequate pain relief, intraarticular needle placement is imperative to identify SIJ pathology and plan future management. This study highlights the importance of obtaining an additional lateral view during fluoroscopy to better evaluate SIJ disease. Methods: A retrospective review of 38 patients who underwent fluoroscopy guided SIJ injection was conducted, for which IRB approval was granted by the MetroWest Medical Center Institutional Review Board. Patient demographics (age, sex, BMI) and pre- and post-operative numerical rating scale (NRS) scores were collected, and initial needle location was reviewed. Patients were placed into groups according to initial needle location. Statistical analysis was conducted using a Mann-Whitney U-test with significance defined as p < 0.05. Results: The 21 females and 17 males had a mean age and BMI of 70.5 years and 27.8 kg/m2, respectively. Thirty-one patients had initial intraarticular needle placement confirmed with lateral arthrogram, and 7 patients had initial periarticular needle placement, requiring needle readjustment in lateral confirmatory view. Both groups had similar demographic characteristics. No statistically significant differences were found between the two groups' mean NRS score improvement (p=0.108). Conclusion: Using only the AP or oblique view during needle placement results in miss rates of nearly 20% while adding a lateral view can lower miss rates to near 0%. While pain relief may be adequate in either case, proper diagnosis and future management relies upon accurate needle placement.

Accessibility and Ease of Use in Neuromodulation Devices.

BACKGROUND: The utilization of neuromodulation therapy continues to grow as therapeutic indications expand. These conditions often present with comorbid physical, visual, and auditory impairments. Patients with disabilities in these categories may have difficulty operating their devices. Thus, reviewing the accessibility and inclusive design of neuromodulation devices is imperative to ensure equal access for patients of all ability levels. To date, the literature provides little insight into this topic. MATERIALS AND METHODS: Manufacturers of Food and Drug Administration-approved neuromodulation devices in the United States completed our electronic survey to assess neuromodulation device features, universal/inclusive design guidelines, and methods used to make the device accessible to patients with disabilities. RESULTS: We assessed 11 devices from seven manufacturers. Of those, there were six spinal cord, two peripheral nerve, and three deep brain stimulators. Of all respondents, 91% used universal inclusive design guidelines. Of the studied devices, 91% have an interface that uses visual feedback, and 82% have an interface that uses auditory feedback. All surveyed devices were reported to have an interface that requires physical handling. DISCUSSION: Our study found that most devices incorporate auditory signals, buttons with raised indentations, speech commands, or other useful features to assist those with visual disabilities. Visual interfaces may be sufficient for a patient with hearing impairment to use all the surveyed devices. However, dual sensory impairment presents a significant limitation in all devices surveyed. Furthermore, the biggest barrier to using neuromodulation devices was physical impairment because all surveyed devices require physical handling. CONCLUSIONS: Manufacturers have awareness of universal inclusive design principles. However, our study was unable to find a device that is accessible to all users regardless of ability. As such, it is critical to involve universal design principles to ensure that inclusive devices are available to improve patient adherence, treatment efficacy, and outcomes.

Multifidus dysfunction and restorative neurostimulation: a scoping review.

OBJECTIVE: Chronic low back pain (CLBP) is multifactorial in nature, with recent research highlighting the role of multifidus dysfunction in a subset of nonspecific CLBP. This review aimed to provide a foundational reference that elucidates the pathophysiological cascade of multifidus dysfunction, how it contrasts with other CLBP etiologies and the role of restorative neurostimulation. METHODS: A scoping review of the literature. RESULTS: In total, 194 articles were included, and findings were presented to highlight emerging principles related to multifidus dysfunction and restorative neurostimulation. Multifidus dysfunction is diagnosed by a history of mechanical, axial, nociceptive CLBP and exam demonstrating functional lumbar instability, which differs from other structural etiologies. Diagnostic images may be used to grade multifidus atrophy and assess other structural pathologies. While various treatments exist for CLBP, restorative neurostimulation distinguishes itself from traditional neurostimulation in a way that treats a different etiology, targets a different anatomical site, and has a distinctive mechanism of action. CONCLUSIONS: Multifidus dysfunction has been proposed to result from loss of neuromuscular control, which may manifest clinically as muscle inhibition resulting in altered movement patterns. Over time, this cycle may result in potential atrophy, degeneration and CLBP. Restorative neurostimulation, a novel implantable neurostimulator system, stimulates the efferent lumbar medial branch nerve to elicit repetitive multifidus contractions. This intervention aims to interrupt the cycle of dysfunction and normalize multifidus activity incrementally, potentially restoring neuromuscular control. Restorative neurostimulation has been shown to reduce pain and disability in CLBP, improve quality of life and reduce health care expenditures.

Best Practice Guidelines on the Diagnosis and Treatment of Vertebrogenic Pain with Basivertebral Nerve Ablation from the American Society of Pain and Neuroscience.

Chronic low back pain is a worldwide leading cause of pain and disability. Degenerative disc disease has been the presumptive etiology in the majority of cases of chronic low back pain (CLBP). More recent study and treatments have discovered that the vertebral endplates play a large role in CLBP in a term defined as vertebrogenic back pain. As the vertebral endplates are highly innervated via the basivertebral nerve (BVN), this has resulted in a reliable target in treating patients suffering from vertebrogenic low back pain (VLBP). The application of BVN ablation for patients suffering from VLBP is still in its early stages of adoption and integration into spine care pathways. BVN ablation is grounded in a solid foundation of both pre-clinical and clinical evidence. With the emergence of this therapeutic option, the American Society of Pain and Neuroscience (ASPN) identified the need for formal evidence-based guidelines for the proper identification and selection of patients for BVN ablation in patients with VLBP. ASPN formed a multidisciplinary work group tasked to examine the available literature and form best practice guidelines on this subject. Based on the United States Preventative Task Force (USPSTF) criteria for grading evidence, gives BVN ablation Level A grade evidence with high certainty that the net benefit is substantial in appropriately selected individuals.

Non-Spinal Neuromodulation of the Lumbar Medial Branch Nerve for Chronic Axial Low Back Pain: A Narrative Review.

Chronic low back pain remains highly prevalent, costly, and the leading cause of disability worldwide. Symptoms are complex and treatment involves an interdisciplinary approach. Due to diverse anatomical etiologies, treatment outcomes with interventional options are highly variable. A novel approach to treating chronic axial low back pain entails the use of peripheral nerve stimulation to the lumbar medial branch nerve, and this review examines the clinical data of the two different, commercially available, non-spinal neuromodulation systems. This review provides the clinician a succinct narrative that presents up-to-date data objectively. Our review found ten clinical studies, including one report of two cases, six prospective studies, and three randomized clinical trials published to date. Currently, there are different proposed mechanisms of action to address chronic axial low back pain with different implantation techniques. Evidence suggests that peripheral nerve stimulation of the lumbar medial branch nerve may be effective in improving pain and function in patients with chronic axial low back pain symptoms at short and long term follow up, with good safety profiles. Further long-term data is needed to consider this intervention earlier in the pain treatment algorithm, but initial data are promising.

Evaluation of a simulated pivot shift test: a biomechanical study.

PURPOSE: Double-bundle anterior cruciate reconstructions have led to an increased interest in quantifying anterolateral rotatory stability. The application of combined internal rotation and valgus torques to the knee can more nearly recreate the anterolateral subluxation that occurs in the pivot shift test in vitro compared to coupled internal rotation torque and anterior tibial loads. METHODS: Twelve non-paired cadaveric knees were biomechanically tested with the ACL intact and sectioned. For each test state, six-degree-of-freedom positional data were collected for two simulated pivot shift loads consisting of a 5-Nm internal rotation torque coupled with either a 10-Nm valgus torque or an 88 N anterior tibial load at 0°, 20°, 30°, 60°, and 90° of knee flexion. RESULTS: The coupled internal rotation and valgus torques produced a significant increase in anterolateral subluxation between the ACL intact and sectioned states at all tested angles except 90º (5.9 ± 0.4 mm at 0°, 4.3 ± 0.6 mm at 20°, 3.5 ± 0.6 mm at 30°, 2.1 ± 0.6 mm at 60°). The coupled internal rotation and an anterior tibial load produced significant increases between the ACL intact and sectioned states at all tested angles except 30º (5.4 ± 0.5 mm at 0°, 3.7 ± 0.5 mm at 20°, 2.1 ± 0.8 mm at 60°, 1.4 ± 0.3 mm at 90°). CONCLUSIONS: We found that the coupled internal rotation and valgus torques best recreated the anterolateral subluxation that occurs in the pivot shift in vitro. This study describes an anterolateral subluxation test for ACL integrity in the laboratory setting.

Radiographic landmarks for tunnel positioning in double-bundle ACL reconstructions.

PURPOSE: The purpose of this study was to establish quantitative and qualitative radiographic landmarks for identifying the femoral and tibial attachment sites of the AM and PL bundles of the native ACL and to assess the reproducibility of identification of these landmarks using intraclass correlation coefficients. It was hypothesized that the radiographic positions of the AM and PL bundles could be defined in relation to anatomic landmarks and radiographic reference lines. METHODS: The femoral and tibial attachment sites of the AM and PL bundles on twelve cadaveric knees were labeled with radio-opaque markers. The positions of the AM and PL bundle attachment sites were quantified on radiographs by three independent examiners. RESULTS: On the lateral femoral view, the AM bundle was located at 21.6 ± 5.6% of the sagittal diameter of the femur drawn along Blumensaat's line and 14.2 ± 7.7% distal to the notch roof along the maximum notch height. The PL bundle was located at 28.9 ± 4.6% of the sagittal diameter and 42.3 ± 6.0% of the notch height. The knee flexion angle at which the AM and PL bundle attachment sites were horizontally oriented was 115 ± 7.1°. On the tibial AP view, the AM and PL bundles were located at 44.2 ± 3.4 and 50.1 ± 2.1%, respectively, from the medial aspect of the tibia along its coronal diameter. On the lateral view, the distances from the AM and PL bundles to the anterior tibial margin measured along the tibial sagittal diameter were 36.3 ± 3.8 and 51.0 ± 4.0%, respectively. The center of the PL bundle attachment was located almost precisely at the center of the tibial plateau in both the coronal and sagittal planes. CONCLUSIONS: This study defines the radiographic locations of the femoral and tibial bundle attachment sites of the native ACL and a reliable and transferrable protocol for identifying these sites on radiographs in relation to surrounding landmarks and digitally projected reference lines. In addition, it was found that the femoral attachments of the AM and PL bundles were horizontally aligned at 115° of knee flexion and the PL bundle tibial attachment was located essentially at the center of the tibia.

Arthroscopically pertinent landmarks for tunnel positioning in single-bundle and double-bundle anterior cruciate ligament reconstructions.

BACKGROUND: Quantification of the overall anterior cruciate ligament (ACL) and anteromedial (AM) and posterolateral (PL) bundle centers in respect to arthroscopically pertinent bony and soft tissue landmarks has not been thoroughly assessed. HYPOTHESIS: A standardized anatomical measurement method can quantitate the locations of the ACL and AM and PL bundle centers in reference to each other and anatomical landmarks. STUDY DESIGN: Descriptive laboratory study. METHODS: Quantification of the ACL and its bundle attachments was performed on 11 cadaveric knees using a radio frequency-tracking device. RESULTS: The tibial ACL attachment center was 7.5 mm medial to the anterior horn of the lateral meniscus, 13.0 mm anterior to the retro-eminence ridge, and 10.5 mm posterior to the ACL ridge. The femoral ACL attachment center was 1.7 mm proximal to the bifurcate ridge and 6.1 mm posterior to the lateral intercondylar ridge. The tibial AM attachment center was 8.3 mm medial to the anteromedial aspect of the lateral meniscus anterior horn, 17.8 mm anterior to the retro-eminence ridge, and 5.6 mm posterior to the ACL ridge. The femoral AM attachment center was 4.8 mm proximal to the bifurcate ridge and 7.1 mm posterior to the lateral intercondylar ridge. The tibial PL bundle attachment center was 6.6 mm medial to the posteromedial aspect of the lateral meniscus anterior horn, 10.8 mm anteromedial to the root attachment of the lateral meniscus posterior horn, and 8.4 mm anterior to the retro-eminence ridge. The femoral PL bundle attachment center was 5.2 mm distal to the bifurcate ridge and 3.6 mm posterior to the lateral intercondylar ridge. CONCLUSION: The authors developed a comprehensive compilation of measurements of arthroscopically pertinent bony and soft tissue landmarks that quantitate the ACL and its individual bundle attachment centers on the tibia and femur. CLINICAL RELEVANCE: These clinically relevant arthroscopic landmarks may enhance single- and double-bundle ACL reconstructions through improved tunnel placement.

Kinematic impact of anteromedial and posterolateral bundle graft fixation angles on double-bundle anterior cruciate ligament reconstructions.

BACKGROUND: Currently in double-bundle anterior cruciate ligament (ACL) reconstructions, the range of knee flexion angles that surgeons use for anteromedial (AM) and posterolateral (PL) bundle graft fixation spans from 0 degrees to 90 degrees for both bundle grafts. Despite the recent popularity of this procedure, no consensus exists on an optimal set of AM and PL graft fixation angles. HYPOTHESIS: Graft fixation angles that simulate the native tensioning relationship of the AM and PL bundles will produce kinematic results similar to the intact knee, while graft fixation angles that do not simulate this relationship will under- or overconstrain the knee. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve cadaveric knees were biomechanically tested in the intact state, ACL-sectioned state, and a randomized order of 7 double-bundle ACL reconstructed states at multiple graft fixation angle combinations. For each test state, data were collected for 88 N anterior tibial loads, 10 N.m valgus torques, 5 N.m internal rotation torques, and 2 simulated pivot shift loads consisting of a 5 N.m internal rotation torque coupled with either a 10 N.m valgus torque or an 88 N anterior tibial load at 0 degrees, 20 degrees, 30 degrees, 60 degrees, and 90 degrees of knee flexion. RESULTS: The AM and PL graft fixation angle combinations of 0 degrees /0 degrees (AM graft fixation angle/PL graft fixation angle), 60 degrees /0 degrees, 45 degrees /15 degrees, and 75 degrees /15 degrees restored normal laxity to the reconstructed knee in all of the biomechanical tests. The 30 degrees /30 degrees, 60 degrees /60 degrees, and 90 degrees /90 degrees graft fixation angle combinations significantly restricted knee laxity compared with the intact state in various biomechanical tests. CONCLUSION: We found that as long as the PL bundle graft was fixed between 0 degrees and 15 degrees , the AM graft could be fixed up to 75 degrees without restricting knee laxity. However, fixation of the PL graft at 30 degrees of knee flexion and above significantly overconstrained the knee. CLINICAL RELEVANCE: This study provides a range of angles that can be used in double-bundle ACL reconstructions to restore normal knee stability without causing overconstraint.

Sartorial branch of the saphenous nerve in relation to a medial knee ligament repair or reconstruction.

Surgical approaches to repair or reconstruct the medial knee structures note caution to avoid the sartorial branch of saphenous nerve. However, the approximate area of potential iatrogenic nerve injury has not been previously described in relation to landmarks for a medial knee reconstruction. The purpose of this study was to define the course of the sartorial branch of the saphenous nerve in relation to the superficial medial collateral ligament. A total of ten non-paired, fresh-frozen cadaveric knees, with no evidence of prior injury or disease were utilized. Dissection to identify the medial knee structures was performed. The sartorial branch of the saphenous nerve was identified in all specimens. The perpendicular distance from the anterior border of the superficial medial collateral ligament 2 cm distal from the joint line to the sartorial branch of the saphenous nerve was 4.8 +/- 0.9 cm. The distance from the anterior border of the superficial medial collateral ligament to the sartorial branch of the saphenous nerve decreased as the distance was increased distally with a mean distance of 4 cm (4.1 +/- 0.8 cm) distal from the joint line and 6 cm (3.8 +/- 0.8 cm) distal from the joint line. We have characterized the surgically relevant landmark anatomy of the sartorial branch of the saphenous nerve in regards to performing a repair or reconstruction of the medial knee structures. Familiarity with these anatomic landmarks and associated distances from the sartorial branch of the saphenous nerve, we can assess the potential area of vulnerability to this nerve branch intraoperatively.

An in vitro analysis of an anatomical medial knee reconstruction.

BACKGROUND: An anatomical medial knee reconstruction has not been described in the literature. HYPOTHESIS: Knee stability and ligamentous load distribution would be restored to the native state with an anatomical medial knee reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Ten nonpaired cadaveric knees were tested in the intact, superficial medial collateral ligament and posterior oblique ligament-sectioned, and anatomically reconstructed states. Each knee was tested at 0 degrees , 20 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion with a 10-N.m valgus load, 5-N.m external and internal rotation torques, and 88-N anterior and posterior drawer loads. A 6 degrees of freedom electromagnetic motion tracking system measured angulation and displacement changes of the tibia with respect to the femur. Buckle transducers measured the loads on the intact and reconstructed proximal and distal divisions of the superficial medial collateral ligament and the posterior oblique ligament. RESULTS: A significant increase was found in valgus angulation and external rotation after sectioning the medial knee structures at all tested knee flexion angles. This was restored after an anatomical medial knee reconstruction. The authors also found a significant increase in internal rotation at 0 degrees , 20 degrees , 30 degrees , and 60 degrees of knee flexion after sectioning the medial knee structures, which was restored after the reconstruction. A significant increase in anterior translation was observed after sectioning the medial knee structures at 20 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion. This increase in anterior translation was restored following the reconstruction at 20 degrees and 30 degrees of knee flexion, but was not restored at 60 degrees and 90 degrees . A small, but significant, increase in posterior translation was found after sectioning the medial knee structures at 0 degrees and 30 degrees of knee flexion, but this was not restored after the reconstruction. Overall, there were no clinically important differences in observed load on the ligaments when comparing the intact with the reconstructed states for valgus, external and internal rotation, and anterior and posterior drawer loads. Conclusion An anatomical medial knee reconstruction restores near-normal stability to a knee with a complete superficial medial collateral ligament and posterior oblique ligament injury, while avoiding overconstraint of the reconstructed ligament grafts. CLINICAL SIGNIFICANCE: This anatomical medial knee reconstruction technique provides native stability and ligament load distribution in patients with chronic or severe acute medial knee injuries.

The 1:1 versus the 2:2 tunnel-drilling technique: optimization of fixation strength and stiffness in an all-inside double-bundle anterior cruciate ligament reconstruction--a biomechanical study.

BACKGROUND: Double-bundle anterior cruciate ligament (ACL) reconstructions involve drilling 2 tibial tunnels separated by a narrow 2-mm bone bridge. The sequence of reaming and drilling the tibial tunnels for double-bundle ACL reconstructions has not been defined. HYPOTHESIS: Fixing a graft in the posterolateral ACL tibial tunnel before reaming the anteromedial tibial tunnel will reduce the number of complications, as compared with drilling both the anteromedial and posterolateral tunnels before graft fixation, when performing double-bundle ACL reconstructions. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve porcine tibias were divided into 2 groups of 6 specimens. Fresh bovine extensor tendons grafts were fixed in 7-mm tunnels reamed using an inside-out method. Grafts were fixed in a retrograde fashion with 7-mm bioabsorbable retrograde screws. The tibias in group 1 were reconstructed by reaming and reconstructing the posterolateral tunnel before reaming and securing the graft for the anteromedial tunnel (ie, 1:1 method), whereas those in the second group were reconstructed by reaming both tunnels before graft fixation in either (ie, the 2:2 method). The specimens were biomechanically tested with cyclic and load-to-failure parameters. RESULTS: Cyclic testing revealed no significant difference between the 2 methods in displacement or stiffness. In load-to-failure testing, the 1:1 group withstood significantly higher initial failure loads and ultimate loads. Pullout displacement was significantly higher for the 1:1 group. Whereas no tibias in the 1:1 group sustained fractures, 4 from the 2:2 group demonstrated a bone bridge fracture. CONCLUSION: Soft tissue ACL grafts fixed in the tibia with the 1:1 method withstood significantly higher initial and ultimate failure loads and were stiffer than the grafts fixed with the 2:2 method. Tibias fixed with the 1:1 method were also less susceptible to bone bridge fracture. CLINICAL RELEVANCE: The potential for a lower complication rate and greater pullout strength seen with the 1:1 method may prove useful to surgeons performing anatomic double-bundle ACL reconstructions, in addition to other procedures involving reconstructing 2 closely positioned tunnels, including anatomic posterolateral corner and medial collateral reconstructions.