Richard J Herzog’s research while affiliated with Weill Cornell Medicine and other places

Background: Although lumbar zygapophyseal joint synovial cysts are fairly well recognized, they are an uncommon cause of lumbosacral radicular pain. Non-operative treatments include percutaneous aspiration of the cysts under computed tomography or fluoroscopic guidance with a subsequent corticosteroid injection. However, there are mixed results in terms of long-term outcomes and cyst reoccurrence. This study prospectively evaluates percutaneous ruptures of zygapophyseal joint (Z-joint) synovial cysts for the treatment of lumbosacral radicular pain. Objectives: Primary: To determine if percutaneous rupture of symptomatic Z-joint synovial cysts leads to sustained improvements in radicular pain and function. Secondary: To assess the rates of cyst recurrence and progression to surgical intervention following percutaneous rupture of symptomatic Z-joint synovial cysts. Design: Prospective cohort study. Setting: Outpatient academic spine practice. Participants: Adults with primary radicular pain due to a facet synovial cyst. Methods: Participants underwent fluoroscopically guided percutaneous Z-joint synovial cyst ruptures under standard-of-care practice. Data on pain, physical function, satisfaction, and progression to surgery were collected at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year post-rupture. An intention-to-treat analysis was utilized for assessment of patient-reported outcome measures. Main outcome measures: The Numerical Rating Scale, Oswestry Disability Index (ODI), and modified North American Spine Society questionnaires were used to measure pain, function, and satisfaction with the procedure, respectively. Results: Thirty-five participants were included in the study, and data were analyzed by an independent researcher. Statistically significant changes in ODI were reported at 2 weeks, 3 months, and 1 year post-intervention (p=.034, .040, and .039, respectively). A statistically and clinically significant relief of current pain was reported at 2 weeks (p=.025) and 6 weeks (p=.014) with respect to baseline. Patients showed significant improvements for best pain at 6 weeks with respect to baseline (p=.031). Patients' worst pain showed the greatest amount of improvement with clinically meaningful changes at all time points compared to baseline. Patient-reported satisfaction was found nearly 70% of the time at all time points. Forty percent (14/35) of participants required repeat cyst rupture, and 31% (11/35) required surgical interventions. Conclusions: There were statistically and clinically significant improvements in pain and function following percutaneous rupture of Z-joint synovial cysts. Additionally, the outcomes support previous retrospective studies indicating that approximately 40% of patients will need surgery. This study provides further research to determine the utility of this procedure and to precisely define a subset of ideal candidates.

Background context: In today's health-care climate, magnetic resonance imaging (MRI) is often perceived as a commodity-a service where there are no meaningful differences in quality and thus an area in which patients can be advised to select a provider based on price and convenience alone. If this prevailing view is correct, then a patient should expect to receive the same radiological diagnosis regardless of which imaging center he or she visits, or which radiologist reviews the examination. Based on their extensive clinical experience, the authors believe that this assumption is not correct and that it can negatively impact patient care, outcomes, and costs. Purpose: This study is designed to test the authors' hypothesis that radiologists' reports from multiple imaging centers performing a lumbar MRI examination on the same patient over a short period of time will have (1) marked variability in interpretive findings and (2) a broad range of interpretive errors. Study design: This is a prospective observational study comparing the interpretive findings reported for one patient scanned at 10 different MRI centers over a period of 3 weeks to each other and to reference MRI examinations performed immediately preceding and following the 10 MRI examinations. Patient sample: The sample is a 63-year-old woman with a history of low back pain and right L5 radicular symptoms. Outcome measures: Variability was quantified using percent agreement rates and Fleiss kappa statistic. Interpretive errors were quantified using true-positive counts, false-positive counts, false-negative counts, true-positive rate (sensitivity), and false-negative rate (miss rate). Methods: Interpretive findings from 10 study MRI examinations were tabulated and compared for variability and errors. Two of the authors, both subspecialist spine radiologists from different institutions, independently reviewed the reference examinations and then came to a final diagnosis by consensus. Errors of interpretation in the study examinations were considered present if a finding present or not present in the study examination's report was not present in the reference examinations. Results: Across all 10 study examinations, there were 49 distinct findings reported related to the presence of a distinct pathology at a specific motion segment. Zero interpretive findings were reported in all 10 study examinations and only one finding was reported in nine out of 10 study examinations. Of the interpretive findings, 32.7% appeared only once across all 10 of the study examinations' reports. A global Fleiss kappa statistic, computed across all reported findings, was 0.20±0.06, indicating poor overall agreement on interpretive findings. The average interpretive error count in the study examinations was 12.5±3.2 (both false-positives and false-negatives). The average false-negative count per examination was 10.9±2.9 out of 25 and the average false-positive count was 1.6±0.9, which correspond to an average true-positive rate (sensitivity) of 56.4%±11.7 and miss rate of 43.6%±11.7. Conclusions: This study found marked variability in the reported interpretive findings and a high prevalence of interpretive errors in radiologists' reports of an MRI examination of the lumbar spine performed on the same patient at 10 different MRI centers over a short time period. As a result, the authors conclude that where a patient obtains his or her MRI examination and which radiologist interprets the examination may have a direct impact on radiological diagnosis, subsequent choice of treatment, and clinical outcome.

Objectives The association of disc degeneration (DD) and vertebral endplate degeneration (EPD) is still not well understood. This study aimed to find segmental predictive risk factors for DD and EPD and to illuminate associations of the disc, endplate and bone marrow changes in the process of degeneration. Methods After institutional review board approval, 450 lumbar levels, followed up with MRI for at least 4 years, were retrospectively graded for DD according to Pfirrmann (PFG), for EPD according to the endplate score (EPS) and according to the presence, extension and type of Modic changes (MC). Clustered logistic regression and multivariate analysis was applied in nested, matched case-control subgroups to evaluate potential local risk factors for progression. ResultsAn EPS score of ≥4 was identified as an independent risk factor for progression of DD (OR = 2.32, 95%CI:1.07–5.01,p = 0.03) and MC (OR = 5.49,95%CI:2.30–13.10,p < 0.001). Progression of DD was significantly accompanied by progression or evolution of MC (OR = 12.25,95%CI:1.49–100.6,p = 0.02) and with progression of EPS (OR = 1.71, 95%CI:1.00–1.05, p = 0.01). Once advanced DD has occurred, it becomes a risk factor for progression in EPS (OR = 2.24,95%CI:1.23–4.12,p < 0.01). Conclusions The degenerative processes in the disc, endplate and bone marrow are highly associated. An EPS ≥ 4 is an independent risk factor for DD and MC progression in a population with low back pain. Key Points• The degenerative processes in the disc, endplate and bone marrow are associated.• An endplate score ≥4 is a risk factor for DD and MC progression.• Modic changes are last to occur in the development of segmental intervertebral degeneration.• A new segmental grading system is suggested.

Background: Developmental cervical stenosis of the spinal canal predisposes patients to neural compression and loss of function. The Torg-Pavlov ratio has been shown to provide high sensitivity but low specificity for identifying developmental cervical stenosis. A more sensitive and specific radiographic index has not been reported to our knowledge. The objective of this study was to develop and provide an objective, sensitive, and specific radiographic index to assess for developmental cervical stenosis. Methods: The C3 through C6 levels of the cervical spine were analyzed on lateral radiographs of 150 adult patients to determine the spinolaminar line-to-lateral mass distance (SL), lateral mass-to-posterior vertebral body distance (LM), spinolaminar line-to-vertebral body (canal) diameter (CD), and vertebral body diameter (VB). Ratios of these measurements were calculated to eliminate magnification effects. The corresponding true spinal canal diameter was measured using computed tomography (CT) midsagittal sections. Receiver operating characteristic (ROC) curve analysis was performed to identify a radiographic measurement ratio with optimal sensitivity and specificity, using a true canal diameter of <12 mm to define developmental cervical stenosis. Results: Several of the measured ratios demonstrated a strong correlation with the true canal diameter at all cervical levels. However, ROC curve analysis showed that only an LM/CD ratio of ≥0.735 indicated a canal diameter of <12 mm (developmental cervical stenosis). The sensitivity of this ratio at C5 was 83% and its specificity at C5 was 74%. An LM/CD ratio of ≥0.735 measured only at the C5 level also indicated developmental cervical stenosis at any cervical level from C3 through C6 with 76% sensitivity and 80% sensitivity. Other ratios, including the Torg-Pavlov ratio, did not demonstrate an adequate statistical profile to indicate developmental cervical stenosis. The accuracy of the LM/CD ratio was not adversely affected by the patient's sex. Conclusions: This analysis provided a novel index for identifying developmental cervical stenosis: the C5 lateral mass/canal diameter (LM/CD) ratio. We believe that this ratio is the best radiographic measurement available to screen for developmental cervical stenosis in the adult spine patient population. It provides an objective radiographic screening tool for physicians to detect developmental cervical stenosis and decide whether additional imaging or surgical referral is appropriate. Level of evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Background context Provocative discography, an invasive diagnostic procedure involving disc puncture with pressurization, is a test for presumptive discogenic pain in the lumbar spine. The clinical validity of this test is unproven. Data from multiple animal studies confirm that disc puncture causes early disc degeneration. A recent study identified radiographic disc degeneration on magnetic resonance imaging (MRI) performed 10 years later in human subjects exposed to provocative discography. The clinical effect of this disc degeneration after provocative discography is unknown. Purpose The aim of this study was to investigate the clinical effects of lumbar provocative discography on patients subjected to this evaluation method. Study design/setting A prospective, 10-year matched cohort study. Patient sample Subjects (n=75) without current low back pain (LBP) problems were recruited to participate in a study of provocative discography at the L3-S1 discs. A closely matched control cohort was simultaneously recruited to undergo a similar evaluation except for discography injections. Outcome measures The primary outcome variables were diagnostic imaging events and lumbar disc surgery events. The secondary outcome variables were serious LBP events, disability events, and medical visits. Methods The discography subjects and control subjects were followed by serial protocol evaluations at 1, 2, 5, and 10 years after enrollment. The lumbar disc surgery events and diagnostic imaging (computed tomography (CT) or MRI) events were recorded. In addition, the interval and cumulative lumbar spine events were recorded. Results Of the 150 subjects enrolled, 71 discography subjects and 72 control subjects completed the baseline evaluation. At 10-year follow-up, 57 discography and 53 control subjects completed all interval surveillance evaluations. There were 16 lumbar surgeries in the discography group, compared with four in the control group. Medical visits, CT/MRI examinations, work loss, and prolonged back pain episodes were all more frequent in the discography group compared with control subjects. Conclusion The disc puncture and pressurized injection performed during provocative discography can increase the risk of clinical disc problems in exposed patients.

The high incidence of failed back patients in the United States calls for a closer look at the source of the problem. In this paper I examine how variability in quality at the diagnostic stage can contribute to the problem. Although MRIs are widely perceived to be a commodity, I identify three key factors that create variability in the quality of an MRI: imaging equipment, imaging protocols, and subspecialization of the reading radiologist. To evaluate the impact of these quality variables, I am collaborating with Spreemo to run a clinical trial at Hospital for Special Surgery to determine the relationship between MRI quality measures and treatment recommendations, and ultimately patient outcomes.

Spinal subdural hematoma (SSDH) following spine surgery is an extremely rare condition, with only three cases being reported in the literature. Unintended durotomy has been associated with SSDH due to alterations of pressures in the dural compartments. The objective of the present report was to report two rare cases of acute SSDH developed after lumbar decompressive surgery. In one of the patients, the diagnosis of SSDH was followed by urgent hematoma evacuation via durotomy due to the patient's worsening neurological symptoms. In the second patient, the SSDH was treated conservatively due to the absence of severe or progressive motor or sensory deficits. In conclusion, emergency evacuation via durotomy is the treatment of choice for patients with SSDH and neurologic impairment. Conservative management may be indicated in selected cases with absent motor and sensory deficits.

PURPOSE: Anatomical landmarks and their relation to the lumbar vertebrae are well described in subjects with normal spine anatomy, but not for subjects with lumbosacral transitional vertebra (LSTV), in whom correct numbering of the vertebrae is challenging and can lead to wrong-level treatment. The aim of this study was to quantify the value of different anatomical landmarks for correct identification of the lumbar vertebra level in subjects with LSTV. METHODS: After IRB approval, 71 subjects (57 ± 17 years) with and 62 without LSTV (57 ± 17 years), all with imaging studies that allowed correct numbering of the lumbar vertebrae by counting down from C2 (n = 118) or T1 (n = 15) were included. Commonly used anatomical landmarks (ribs, aortic bifurcation (AB), right renal artery (RRA) and iliac crest height) were documented to determine the ability to correctly number the lumbar vertebrae. Further, a tangent to the top of the iliac crests was drawn on coronal MRI images by two blinded, independent readers and named the 'iliac crest tangent sign'. The sensitivity, specificity and the interreader agreement were calculated. RESULTS: While the level of the AB and the RRA were found to be unreliable in correct numbering of the lumbar vertebrae in LSTV subjects, the iliac crest tangent sign had a sensitivity and specificity of 81 % and 64-88 %, respectively, with an interreader agreement of k = 0.75. CONCLUSION: While anatomical landmarks are not always reliable, the 'iliac crest tangent sign' can be used without advanced knowledge in MRI to most accurately number the vertebrae in subjects with LSTV, if only a lumbar spine MRI is available.

OBJECTIVE: Sufficiently sized studies to determine the value of the iliolumbar ligament (ILL) as an identifier of the L5 vertebra in cases of a lumbosacral transitional vertebra (LSTV) are lacking. METHODS: Seventy-one of 770 patients with LSTV (case group) and 62 of 611 subjects without LSTV with confirmed L5 level were included. Two independent radiologists using coronal MR images documented the level(s) of origin of the ILL. The interobserver agreement was analysed using weighted kappa/kappa (wκ/κ) and a Fischer's exact test to assess the value of the ILL as an identifier of the L5 vertebra. RESULTS: The ILL identified the L5 vertebra by originating solely from L5 in 95 % of the controls; additional origins were observed in 5 %. In the case group, the ILL was able to identify the L5 vertebra by originating solely from L5 in 25-38 %. Partial origin from L5, including origins from other vertebra was observed in 39-59 % and no origin from L5 at all in 15-23 % (wκ = 0.69). Both readers agreed that an ILL was always present and its origin always involved the last lumbar vertebra. CONCLUSION: The level of the origin of the ILL is unreliable for identification of the L5 vertebra in the setting of an LSTV or segmentation anomalies. KEY POINTS: • The origin of the ILL is evaluated in subjects with an LSTV. • The origin of the ILL is anatomically highly variable in LSTV. • The ILL is not a reliable landmark of the L5 vertebra in LSTV.