Objective To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. Methodology Systematic assessment of the literature. Evidence I. Lumbar Spine • The evidence for accuracy of diagnostic selective nerve root blocks is limited; whereas for lumbar provocation discography, it is fair. • The evidence for diagnostic lumbar facet joint nerve blocks and diagnostic sacroiliac intraarticular injections is good with 75% to 100% pain relief as criterion standard with controlled local anesthetic or placebo blocks. • The evidence is good in managing disc herniation or radiculitis for caudal, interlaminar, and transforaminal epidural injections; fair for axial or discogenic pain without disc herniation, radiculitis or facet joint pain with caudal, and interlaminar epidural injections, and limited for transforaminal epidural injections; fair for spinal stenosis with caudal, interlaminar, and transforaminal epidural injections; and fair for post surgery syndrome with caudal epidural injections and limited with transforaminal epidural injections. • The evidence for therapeutic facet joint interventions is good for conventional radiofrequency, limited for pulsed radiofrequency, fair to good for lumbar facet joint nerve blocks, and limited for intraarticular injections. • For sacroiliac joint interventions, the evidence for cooled radiofrequency neurotomy is fair; limited for intraarticular injections and periarticular injections; and limited for both pulsed radiofrequency and conventional radiofrequency neurotomy. • For lumbar percutaneous adhesiolysis, the evidence is fair in managing chronic low back and lower extremity pain secondary to post surgery syndrome and spinal stenosis. • For intradiscal procedures, the evidence for intradiscal electrothermal therapy (IDET) and biaculoplasty is limited to fair and is limited for discTRODE. • For percutaneous disc decompression, the evidence is limited for automated percutaneous lumbar discectomy (APLD), percutaneous lumbar laser disc decompression, and Dekompressor; and limited to fair for nucleoplasty for which the Centers for Medicare and Medicaid Services (CMS) has issued a noncoverage decision. II. Cervical Spine • The evidence for cervical provocation discography is limited; whereas the evidence for diagnostic cervical facet joint nerve blocks is good with a criterion standard of 75% or greater relief with controlled diagnostic blocks. • The evidence is good for cervical interlaminar epidural injections for cervical disc herniation or radiculitis; fair for axial or discogenic pain, spinal stenosis, and post cervical surgery syndrome. • The evidence for therapeutic cervical facet joint interventions is fair for conventional cervical radiofrequency neurotomy and cervical medial branch blocks, and limited for cervical intraarticular injections. III. Thoracic Spine • The evidence is limited for thoracic provocation discography and is good for diagnostic accuracy of thoracic facet joint nerve blocks with a criterion standard of at least 75% pain relief with controlled diagnostic blocks. • The evidence is fair for thoracic epidural injections in managing thoracic pain. • The evidence for therapeutic thoracic facet joint nerve blocks is fair, limited for radiofrequency neurotomy, and not available for thoracic intraarticular injections. IV. Implantables • The evidence is fair for spinal cord stimulation (SCS) in managing patients with failed back surgery syndrome (FBSS) and limited for implantable intrathecal drug administration systems. V. ANTICOAGULATION • There is good evidence for risk of thromboembolic phenomenon in patients with antithrombotic therapy if discontinued, spontaneous epidural hematomas with or without traumatic injury in patients with or without anticoagulant therapy to discontinue or normalize INR with warfarin therapy, and the lack of necessity of discontinuation of nonsteroidal anti-inflammatory drugs (NSAIDs), including low dose aspirin prior to performing interventional techniques. • There is fair evidence with excessive bleeding, including epidural hematoma formation with interventional techniques when antithrombotic therapy is continued, the risk of higher thromboembolic phenomenon than epidural hematomas with discontinuation of antiplatelet therapy prior to interventional techniques and to continue phosphodiesterase inhibitors (dipyridamole, cilostazol, and Aggrenox). • There is limited evidence to discontinue antiplatelet therapy with platelet aggregation inhibitors to avoid bleeding and epidural hematomas and/or to continue antiplatelet therapy (clopidogrel, ticlopidine, prasugrel) during interventional techniques to avoid cerebrovascular and cardiovascular thromboembolic fatalities. • There is limited evidence in reference to newer antithrombotic agents dabigatran (Pradaxa) and rivaroxan (Xarelto) to discontinue to avoid bleeding and epidural hematomas and are continued during interventional techniques to avoid cerebrovascular and cardiovascular thromboembolic events. Conclusions Evidence is fair to good for 62% of diagnostic and 52% of therapeutic interventions assessed. Disclaimer The authors are solely responsible for the content of this article. No statement on this article should be construed as an official position of ASIPP. The guidelines do not represent "standard of care."

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An update of comprehensive evidence-based guidelines for interventional techniques in chronic spinal pain. Part II: guidance and recommendations.

Ultra high molecular weight polyethylene (UHMWPE) is a semicrystalline polymer that has been used for over four decades as a bearing surface in total joint replacements. The mechanical properties and wear properties of UHMWPE are of interest with respect to the in vivo performance of UHMWPE joint replacement components. The mechanical properties of the polymer are dependent on both its crystalline and amorphous phases. Altering either phase (i.e., changing overall crystallinity, crystalline morphology, or crosslinking the amorphous phase) can affect the mechanical behavior of the material. There is also evidence that the morphology of UHMWPE, and, hence, its mechanical properties evolve with loading. UHMWPE has also been shown to be susceptible to oxidative degradation following gamma radiation sterilization with subsequent loss of mechanical properties. Contemporary UHMWPE sterilization methods have been developed to reduce or eliminate oxidative degradation. Also, crosslinking of UHMWPE has been pursued to improve the wear resistance of UHMWPE joint components. The 1st generation of highly crosslinked UHMWPEs have resulted in clinically reduced wear; however, the mechanical properties of these materials, such as ductility and fracture toughness, are reduced when compared with the virgin material. Therefore, a 2nd generation of highly crosslinked UHMWPEs are being introduced to preserve the wear resistance of the 1st generation while also seeking to provide oxidative stability and improved mechanical properties.

Ultra high molecular weight polyethylene: mechanics, morphology, and clinical behavior.

Study Design. Systematic review of diagnostic studies. Objective. To update our previous systematic review on the diagnostic accuracy of tests used to diagnose lumbar spinal stenosis. Summary of Background Data. A wide range of clinical, radiological, and electrodiagnostic tests are used to diagnose lumbar spinal stenosis. An accurate diagnosis is vital, because lumbar spinal stenosis may require specific medical advice and treatment. Therefore, it is important to know the accuracy of these diagnostic tests currently available. Methods. A comprehensive literature search was conducted for original diagnostic studies on lumbar spinal stenosis, in which one or more diagnostic tests were evaluated with a reference standard, and diagnostic accuracy was reported or could be calculated. Our previous systematic review included studies up to March 2004; this review is current up to March 2011. Included studies were assessed for their methodological quality using the QUADAS tool. Study characteristics and reported diagnostic accuracy were extracted. Results. Twenty-two additional articles in addition to the 24 included in the previous review met the inclusion criteria. Combined, this resulted in 20 articles concerning imaging tests, 11 articles evaluating electrodiagnostic tests, and 15 articles evaluating clinical tests. Estimates of the diagnostic accuracy of the tests differed considerably. Conclusion. There is a need for a consensus on criteria to define and classify lumbar spinal stenosis. At present, the most promising imaging test for lumbar spinal stenosis is magnetic resonance imaging, avoiding myelography because of its invasiveness and lack of superior accuracy. Electrodiagnostic studies showed no superior accuracy for conventional electrodiagnostic testing compared with magnetic resonance imaging. These tests should be considered in the context of those presenting symptoms with the highest diagnostic value, including radiating leg pain that is exacerbated while standing up, the absence of pain when seated, the improvement of symptoms when bending forward, and a wide-based gait.

Diagnosis of lumbar spinal stenosis: an updated systematic review of the accuracy of diagnostic tests

To estimate the prevalence of degenerative lumbar spinal stenosis (LSS) in adults, identified by clinical symptoms and/or radiological criteria. Systematic review of the literature. Pooled prevalence estimates by care setting and clinical or radiological diagnostic criteria were calculated and plotted [PROSPERO ID: CRD42018109640]. In total, 41 papers reporting on 55 study samples were included. The overall risk of bias was considered high in two-thirds of the papers. The mean prevalence, based on a clinical diagnosis of LSS in the general population, was 11% (95% CI 4–18%), 25% (95% CI 19–32%) in patients from primary care, 29% (95% CI 22–36%) in patients from secondary care and 39% (95% CI 39–39%) in patients from mixed primary and secondary care. Evaluating the presence of LSS based on radiological diagnosis, the pooled prevalence was 11% (95% CI 5–18%) in the asymptomatic population, 38% (95% CI − 10 to 85%) in the general population, 15% (95% CI 13–18%) in patients from primary care, 32% (95% CI 22–41%) in patients from secondary care and 21% (95% CI 16–26%) in a mixed population from primary and secondary care. The mean prevalence estimates based on clinical diagnoses vary between 11 and 39%, and the estimates based on radiological diagnoses similarly vary between 11 and 38%. The results are based on studies with high risk of bias, and the pooled prevalence estimates should therefore be interpreted with caution. With an growing elderly population, there is a need for future low risk-of-bias research clarifying clinical and radiological diagnostic criteria of lumbar spinal stenosis. These slides can be retrieved under Electronic Supplementary Material.

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Prevalence of lumbar spinal stenosis in general and clinical populations: a systematic review and meta-analysis

We reported a case of fracture of a polyethylene tibial post in a 44-year-old woman after 3 years of NexGen posterior-stabilized total knee arthroplasty (Zimmer, Warsaw, IN). Burnishing and delamination of the polyethylene was found around the breakage site of the post, especially over the anterior aspect of the post base. It indicated that the possible failure mechanism was the repeated anterior impingement between the metal femoral cam and polyethylene tibial post. After replacement of the broken insert, the patient obtained complete relief of previous symptoms. To our knowledge, this is the first report of post breakage of a NexGen posterior-stabilized knee prosthesis.

Fracture of the polyethylene tibial post in a NexGen posterior-stabilized knee prosthesis

Although the effect of physical workload on the occurrence of low back pain (LBP) has been extensively investigated, few quantitative studies have examined the morphological changes visualized via magnetic resonance imaging (MRI) in relation to occupational variables. The relationship between the severity of some abnormalities such as lumbar spinal stenosis or spondylolisthesis and physical or psychosocial occupational risk factors has not been investigated previously. In this cross-sectional study patients fulfilled the following inclusion criteria: (1) long-standing (minimum 1-year) LBP radiating down the leg (or not); (2) age more than 40 years; (3) willingness to undergo an MRI of the lumbar spine; and (4) ability to speak Italian. Primary objective of the study was to investigate the association between occupational exposure and morphological MRI findings, while controlling for the individual risk factors for LBP. Secondarily, we looked at the influence of this exposure and the degenerative changes in the lumbar spine on clinical symptoms and the related disability. Lumbar MRI scans from 120 symptomatic patients were supplemented by the results of structured interviews, which provided personal, medical, and occupational histories. All occupational factors were arranged on scales of increasing exposure, whereas pain and disability were assessed using ad hoc validated questionnaires. Evidence of intervertebral disc narrowing or herniation and the occurrence and severity of spinal stenosis and spondylolisthesis was obtained from the MRI scans and a summative degenerative score was then calculated. We detected a direct association between increasing age and the global amount of degenerative change, the severity of intervertebral disc height loss, the number of narrowed discs, stenosis, the number of stenotic levels, and spondylolisthesis. Physical occupational exposure was not associated with the presence of lumbar disc degeneration and narrowing per se, but a higher degree of such an exposure was directly associated with a higher degree of degeneration (P=0.017). Spondylolistesis and stenosis were positively related to heavy workload (P=0.014) and the manual handling of materials (P=0.023), respectively. Psychosocial occupational discomfort was directly associated to stenosis (P=0.041) and number of stenotic levels (P=0.019). A heavier job workload was the only occupational factor positively related to the degree of disability at the multivariate analysis (P=0.002). Total amount of degeneration in the lumbar spine directly influenced pain duration (P=0.011) and degree of disability (P=0.050). These results suggest that caution should be exercised when symptomatic subjects with evidence of degenerative changes on MRI scans engage in strenuous physical labor.

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Relationship between alterations of the lumbar spine, visualized with magnetic resonance imaging, and occupational variables.

We report a case of acute failure of a Genesis total knee arthroplasty (Smith and Nephew Orthopaedics, Memphis, TN) resulting from fracture of the eminence of the polyethylene posterior-stabilized tibial insert implanted in a revision procedure. A hyperflexion movement was responsible for shear stress on the insert with subsequent breakage. The correct diagnosis was obtained by arthroscopy, and the open substitution of the broken insert led to complete recovery of the prosthesis. This is the first report of mechanical breakage of a Genesis prosthesis.

Fracture of posterior-stabilized tibial insert in a genesis knee prosthesis

A cross-sectional study was conducted to evaluate the possible use of a low-cost radiation-free technique in the prediction of degenerative changes in the lumbar spine. Although an inverse correlation between osteoporosis and degenerative changes in the lumbar spine has been reported, no previous studies have asked whether there is a correlation between calcaneal quantitative ultrasound results and degenerative findings in the lumbar spine. In 117 patients with low back pain or pain in the lower limb, ultrasonographic parameters (speed of sound, broadband ultrasound attenuation, stiffness) of the calcaneus were correlated with evidence of degenerative changes and stenosis on magnetic resonance scans of the lumbar spine. Linear and logistic regression, as well as receiver operator characteristic curve analyses, were used to evaluate the correlation. Lumbar spine stenosis was associated with elevated calcaneal ultrasonographic parameters, particularly speed of sound. For the identification of a narrowing of the lumbar spinal canal below 100 mm2 of dural sac cross-sectional area, speed of sound showed 89% sensitivity and 75% specificity in males older than 60 years. In male patients, we also found a significant positive correlation between ultrasonographic parameters and scores on a degenerative scale that primarily reflects intervertebral disc degeneration (P=0.019 for speed of sound; P=0.039 for stiffness). In conclusion, calcaneal quantitative ultrasound is frequently used in elderly patients with low back pain as a diagnostic test for osteoporosis. The incidental finding of high values on ultrasonographic parameters in these subjects, particularly in males, is highly correlated with lumbar spine degeneration and stenosis, and can help to identify those symptomatic patients needing more extensive diagnostic testing.

Giovanni Lotti

Papers

Relationship between alterations of the lumbar spine, visualized with magnetic resonance imaging, and occupational variables.

Fracture of posterior-stabilized tibial insert in a genesis knee prosthesis

Quantitative ultrasound measurements of the calcaneus in the prediction of lumbar spine degeneration.

Dislocation of total hip prosthesis by false aneurysm of the medial circumflex femoral artery.