Surgery versus Conservative Care for Persistent Sciatica Lasting 4 to 12 Months.

BACKGROUND: The treatment of chronic sciatica caused by herniation of a lumbar disk has not been well studied in comparison with acute disk herniation. Data are needed on whether diskectomy or a conservative approach is better for sciatica that has persisted for several months. METHODS: In a single-center trial, we randomly assigned patients with sciatica that had lasted for 4 to 12 months and lumbar disk herniation at the L4-L5 or L5-S1 level in a 1:1 ratio to undergo microdiskectomy or to receive 6 months of standardized nonoperative care followed by surgery if needed. Surgery was performed by spine surgeons who used conventional microdiskectomy techniques. The primary outcome was the intensity of leg pain on a visual analogue scale (ranging from 0 to 10, with higher scores indicating more severe pain) at 6 months after enrollment. Secondary outcomes were the score on the Oswestry Disability Index, back and leg pain, and quality-of-life scores at 6 weeks, 3 months, 6 months, and 1 year. RESULTS: From 2010 through 2016, a total of 790 patients were screened; of those patients, 128 were enrolled, with 64 in each group. Among the patients assigned to undergo surgery, the median time from randomization to surgery was 3.1 weeks; of the 64 patients in the nonsurgical group, 22 (34%) crossed over to undergo surgery at a median of 11 months after enrollment. At baseline, the mean score for leg-pain intensity was 7.7 in the surgical group and 8.0 in the nonsurgical group. The primary outcome of the leg-pain intensity score at 6 months was 2.8 in the surgical group and 5.2 in the nonsurgical group (adjusted mean difference, 2.4; 95% confidence interval, 1.4 to 3.4; P<0.001). Secondary outcomes including the score on the Owestry Disability Index and pain at 12 months were in the same direction as the primary outcome. Nine patients had adverse events associated with surgery, and one patient underwent repeat surgery for recurrent disk herniation. CONCLUSIONS: In this single-center trial involving patients with sciatica lasting more than 4 months and caused by lumbar disk herniation, microdiskectomy was superior to nonsurgical care with respect to pain intensity at 6 months of follow-up. (Funded by Physicians' Services Incorporated Foundation; ClinicalTrials.gov number, NCT01335646.).

The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation.

BACKGROUND: Intermittent claudication can be neurogenic or vascular. Physicians use a profile based on symptom attributes to differentiate the 2 types of claudication, and this guides their investigations for diagnosis of the underlying pathology. We evaluated the validity of these symptom attributes in differentiating neurogenic from vascular claudication. METHODS: Patients with a diagnosis of lumbar spinal stenosis (LSS) or peripheral vascular disease (PVD) who reported claudication answered 14 questions characterizing their symptoms. We determined the sensitivity, specificity and positive and negative likelihood ratios (PLR and NLR) for neurogenic and vascular claudication for each symptom attribute. RESULTS: We studied 53 patients. The most sensitive symptom attribute to rule out LSS was the absence of "triggering of pain with standing alone" (sensitivity 0.97, NLR 0.050). Pain alleviators and symptom location data showed a weak clinical significance for LSS and PVD. Constellation of symptoms yielded the strongest associations: patients with a positive shopping cart sign whose symptoms were located above the knees, triggered with standing alone and relieved with sitting had a strong likelihood of neurogenic claudication (PLR 13). Patients with symptoms in the calf that were relieved with standing alone had a strong likelihood of vascular claudication (PLR 20.0). CONCLUSION: The classic symptom attributes used to differentiate neurogenic from vascular claudication are at best weakly valid independently. However, certain constellation of symptoms are much more indicative of etiology. These results can guide general practitioners in their evaluation of and investigation for claudication.

CONTEXTE: La claudication intermittente peut avoir une étiologie neurogène ou vasculaire. Les médecins utilisent un profil fondé sur les particularités des symptômes pour distinguer l'une de l'autre et ceci oriente leur choix des méthodes de diagnostic de la pathologie sous-jacente. Nous avons évalué la validité de ces particularités des symptômes utilisées pour distinguer la claudication d'origine neurogène de la claudication d'origine vasculaire. MÉTHODES: Des patients atteints d'une sténose spinale lombaire (SSL) ou d'une maladie vasculaire périphérique (MVP) avérées qui se plaignaient de claudication ont réponduà 14 questions afin de caractériser leurs symptômes. Nous avons déterminé la sensibilité, la spécificité et les rapports de probabilité positifs et négatifs (RPP et RPN) à l'égard de la claudication neurogène ou vasculaire pour chacune des particularités des symptômes. RÉSULTATS: Notre étude a regroupé 53 patients. La particularité des symptômes dotée de la sensibilité la plus élevée pour ce qui est d'écarter le diagnostic de SSL a été l'absence de « déclenchement de la douleur à la simple station debout ¼ (sensibilité 0,97; RPN 0,050). Les données sur ce qui soulageait la douleur et sur la localisation des symptômes ont eu une faible portée clinique en ce qui a trait à la SSL et à la MVP. La présence d'une constellation de symptômes a donné lieu aux associations les plus solides : les patients qui manifestaient un signe du « panier d'épicerie ¼ positif et dont les symptômes étaient localisés au-dessus du genou, déclenchés par la station debout seule et soulagés en position assise présentaient une forte probabilité de claudication d'origine neurogène (RPP 13). Chez les patients dont les symptômes étaient localisés au mollet et qui étaient soulagés par la station debout, on notait une forte probabilité de claudication d'origine vasculaire (RPP 20,0). CONCLUSION: Considérés individuellement, les attributs classiques des symptômes utilisés pour distinguer la claudication d'origine neurogène de la claudication d'origine vasculaire sont au mieux faiblement valides. Toutefois, certaines constellations de symptômes éclairent bien davantage l'étiologie. Ces résultats peuvent guider l'omnipraticien dans son examen et dans son diagnostic de la claudication.

Industry and evidence-based medicine: Believable or conflicted? A systematic review of the surgical literature.

BACKGROUND: Over the last few decades medical research and development has come to depend more heavily on the financial support of industry. However, there is concern that financial relations between the medical community and medical industry could unduly influence medical research and therefore patient care. Our objective was to determine whether conflict of interest owing to authors'/investigators' financial affiliation with industry associated with their academic research has been identified in the surgical literature. In particular, we sought to answer the following questions: What is the extent of such conflict of interest? Does conflict of interest bias the results of academic surgical research in favour of industry? What are the potential causes of this proindustry bias? METHODS: We conducted a systematic review of the literature in May 2008 using the OVID SP search engine of MEDLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, DARE and Health Technology Assessment. Quantitative studies that included a methods section and reported on conflict of interest as a result of industry funding in surgery-related research specifically were included in our analysis. RESULTS: The search identified 190 studies that met our criteria. Author/investigator conflict of interest owing to financial affiliation with industry associated with their academic research is well documented in the surgical literature. Six studies demonstrated that authors with such conflicts of interest were significantly more likely to report a positive outcome than authors without industry funding, which demonstrates a proindustry bias. Two studies found that the proindustry bias could not be explained by variations in study quality or sample size. CONCLUSION: The conflict of interest that exists when surgical research is sponsored by industry is a genuine concern.

Spinal cord injuries related to cervical spine fractures in elderly patients: factors affecting mortality.

BACKGROUND CONTEXT: Spinal cord injuries (SCIs) related to cervical spine (C-spine) fractures can cause significant morbidity and mortality. Aggressive treatment often required to manage instability associated with C-spine fractures is complicated and hazardous in the elderly population. PURPOSE: To determine the mortality rate of elderly patients with SCIs related to C-spine fractures and identify factors that contribute toward a higher risk for negative outcomes. STUDY DESIGN/SETTING: Retrospective cohort study at two Level 1 trauma centers. PATIENT SAMPLE: Thirty-seven consecutive patients aged 60 years and older who had SCIs related to C-spine fractures. OUTCOME MEASURES: Level of injury, injury severity, preinjury medical comorbidities, treatment (operative vs. nonoperative), and cause of death. METHODS: Hospital medical records were reviewed independently. Baseline radiographs and computed tomography or magnetic resonance imaging scans were examined to permit categorization according to the mechanistic classification by Allen and Ferguson of subaxial C-spine injuries. Univariate logistic regression analyses were performed to identify factors related to in-hospital mortality and ambulation at discharge. There were no funding sources or potential conflicts of interest to disclose. RESULTS: The in-hospital mortality rate was 38%. Respiratory failure was the leading cause of death. Preinjury medical comorbidities, age, and operative versus nonoperative treatment did not affect mortality. Injury level at or above C4 was associated with a 7.1 times higher risk of mortality compared with injuries below C4 (p=.01). Complete SCI was associated with a 5.1 times higher risk of mortality compared with incomplete SCI (p=.03). Neurological recovery was uncommon. Apart from severity of initial SCI, no other factor was related to ambulatory disposition at discharge. CONCLUSIONS: In this elderly population, neurological recovery was poor and the in-hospital mortality rate was high. The strongest risk factors for mortality were injury level and severity of SCI. Although each case of SCI related to C-spine fractures is different, physicians may be able to use these findings to help better determine the prognosis and guide subsequent treatment.

Comparative assessment of sacral screw loosening augmented with PMMA versus a calcium triglyceride bone cement.

STUDY DESIGN: A calcium triglyceride bone cement (CTBC) was compared with the gold-standard polymethylmethacrylate (PMMA) to assess the stability of augmented sacral screw fixation under cyclic loading. OBJECTIVE: To determine whether CTBC augmentation of a pedicle screw would provide a similar level of fixation in the S1 pedicles compared with PMMA augmentation. SUMMARY OF BACKGROUND DATA: Numerous studies have shown the advantages of using PMMA to augment screw fixation; however, its biomechanical properties are not ideal. CTBC offers potential benefits such as being low exothermic, a modulus of elasticity closer to bone, and the potential for osteoconductivity, but its comparative performance in this situation has not been previously evaluated. METHODS: Six cadaveric sacra were used in this study; 3.0 mL volumes of PMMA (Simplex P) and CTBC (Kryptonite™ Bone Cement) were injected into contralateral screw tracts, with the screw immediately inserted after cement injection. After a 12-hour setting period, the sacrum was potted in a custom fixture and mounted to the frame of a materials testing machine. Alternating flexion and extension bending moments were applied at 1 Hz. Flexion moments were applied starting at 0.5 Nm and increased by 1 Nm after every 1000 cycles until the screw had reached 6° of rotation relative to its starting position. Extension moments were maintained at 0.5 Nm. Screw rotation relative to bone was determined in real time by a custom optical tracking system and was analyzed using two-way repeated-measures analyses of variance (ANOVAs) and post hoc Student-Newman-Keuls tests (α = 0.05). RESULTS: To reach 6° of screw rotation, the PMMA-augmented screw required more loading cycles (15,464 ± 2526 vs. 10,277 ± 1762 cycles; P = 0.006) and a larger applied moment (15.3 ± 2.2 vs. 10.5 ± 1.7 Nm; P = 0.010) than CTBC-augmented screw. CONCLUSION: The PMMA augmentation provided increased resistance to cyclic loading compared with the CTBC augmentation for sacral pedicle screw fixation, but both augmentations well exceeded previously published findings for nonaugmented screws.

Comparing the fixation of a novel hollow screw versus a conventional solid screw in human sacra under cyclic loading.

STUDY DESIGN: The loosening rates of two monocortical pedicle screw designs (hollow and solid) were compared in a cadaveric sacrum model subjected to cyclic loading. OBJECTIVE: To determine if a hollow screw would be more resistant to loosening than a solid pedicle screw when placed into the pedicles of S1 and tested under stair-cased cyclic loading. SUMMARY OF BACKGROUND DATA: Screw loosening is a clinical problem for lumbosacral fusions. No previous literature has evaluated the use of a monocortical hollow screw within the sacrum; however, in other vertebral bodies, results of using this screw have been varied. METHODS: Seven fresh-frozen cadaveric sacra were thawed and stripped of soft tissues. Solid and hollow screws were inserted contralaterally into the pedicles of S1. A materials testing machine applied alternating flexion and extension bending moments at 1 Hz, to each screw independently, via a standard connecting rod. Flexion moments were applied starting at 0.5 Nm and increased by 0.5 Nm after every 1000 cycles until the screw had visibly failed. Extension moments were maintained at 0.5 Nm. Screw rotation (flexion) relative to the sacrum was recorded using a custom optical tracking system, and analyzed using 2-way repeated measures analyses of variances and post hoc Student-Newman-Keuls tests (alpha = 0.05). RESULTS: Screw rotation tended to gradually increase to six degrees, after which the screw was grossly loose. Overall, the hollow screw required fewer loading cycles (P = 0.004) and less applied moment (P = 0.003) to achieve the same magnitude of screw rotation as the solid screw. To achieve 6 degrees of screw rotation, the number of loading cycles were 6301 +/- 2161 and 11151 +/- 4221 for hollow and solid screws, respectively. The corresponding applied moments were 3.5 +/- 1.0 Nm and 5.8 +/- 2.0 Nm. CONCLUSION.: The novel hollow screw was less resistant to loosening when compared with a conventional solid pedicle screw in this sacral model under cyclic loading.