The anatomy of the lateral branches of the sacral dorsal rami: implications for radiofrequency ablation.

BACKGROUND: The sacroiliac joint (SIJ) is a major source of pain in patients with chronic low back pain. Radiofrequency ablation (RFA) of the lateral branches of the dorsal sacral rami that supply the joint is a treatment option gaining considerable attention. However, the position of the lateral branches (commonly targeted with RFA) is variable and the segmental innervation to the SIJ is not well understood. OBJECTIVES: Our objective was to clarify the lateral branches' innervation of the SIJ and their specific locations in relation to the dorsal sacral foramina, which are the standard RFA landmark. METHODS: Dissections and photography of the L5 to S4 sacral dorsal rami were performed on 12 hemipelves from 9 donated cadaveric specimens. RESULTS: There was a broad range of exit points from the dorsal sacral foramina: ranging from 12:00 - 6:00 position on the right side and 6:00 - 12:00 on the left positions. Nine of 12 of the hemipelves showed anastomosing branches from L5 dorsal rami to the S1 lateral plexus. LIMITATIONS: The limitations of this study include the use of a posterior approach to the pelvic dissection only, thus discounting any possible nerve contribution to the anterior aspect of the SIJ, as well as the possible destruction of some L5 or sacral dorsal rami branches with the removal of the ligaments and muscles of the low back. CONCLUSION: Widespread variability of lateral branch exit points from the dorsal sacral foramen and possible contributions from L5 dorsal rami and superior gluteal nerve were disclosed by the current study. Hence, SIJ RFA treatment approaches need to incorporate techniques which address the diverse SIJ innervation.

Environmental conditions and performance outcomes: a preliminary report of implications for patient outcomes.

BACKGROUND: Whereas a host of studies have established various forms of experimental bias, few clinical investigations have examined the relationship of the behavior of the observer or examiner to a subject's physical performance. OBJECTIVE: To measure the grip strength of volunteers in 2 distinct clinical "environments." METHODOLOGY: Twenty subjects were randomized in a crossover design to undergo grip strength testing in positive and negative environments as created by the distinctly different behavioral/communication approaches of the research staff. Each subject underwent 4 consecutive trials in both settings. RESULTS: A paired t- test was conducted to determine if the contrasting environments impacted the volunteer's performance. Eight of the 10 subjects demonstrated a significantly stronger grip in the positive environment. One subject's grip remained essentially unchanged and one subject provided a slightly higher performance in the negative setting. CONCLUSIONS: The study suggests that clinical environmental conditions influence the physical performance of a grip strength maneuver. Thus, it seems probable that clinical or experimental settings may affect diagnostic test results and/or functional outcome.

Does opioid use for pain management warrant routine bone mass density screening in men?

BACKGROUND: Although opioids are known to inhibit testosterone production and bone formation, no prior study has investigated the relationship between opioid use in male subjects and bone mass density measurements. METHOD: Eighty-one male patients who had been using opioids for a period of time from a few weeks to 20 years were included in this study. Blood samples were obtained to examine the total testosterone level of these subjects and each patient also had a bone mass density scan. This study was done retrospectively using lab values collected during the normal care of the patient. No extra measures were done relative to this study and all patient identifiers were removed from the data prior to analysis. Accordingly, there was no need here for an IRB or patient consent. RESULTS: Fifty percent of hypogonadal men had bone mass densities in the osteoporotic or osteopenic range. Forty-two percent of the men who had total testosterone levels within the normal range also had bone mass densities within these ranges. Other factors may also influence the bone mass density results. For example, in this study 52% of the patients disclosed that they smoke. CONCLUSION: Of this population almost half of the men had bone mass densities in the osteopenic/osteoporotic ranges, regardless of their total testosterone blood level. Therefore, monitoring the total testosterone blood level is not a reliable method to determine the risk for developing opioid-associated osteoporosis. Further investigations should be done to help evaluate whether routine bone mass density screenings for men prescribed opioids for chronic pain management may be warranted.

The sacroiliac joint: anatomy, physiology and clinical significance.

The sacroiliac joint (SIJ) is a putative source of low back pain. The objective of this article is to provide clinicians with a concise review of SIJ structure and function, diagnostic indicators of SIJ-mediated pain, and therapeutic considerations. The SIJ is a true diarthrodial joint with unique characteristics not typically found in other diarthrodial joints. The joint differs with others in that it has fibrocartilage in addition to hyaline cartilage, there is discontinuity of the posterior capsule, and articular surfaces have many ridges and depressions. The sacroiliac joint is well innervated. Histological analysis of the sacroiliac joint has verified the presence of nerve fibers within the joint capsule and adjoining ligaments. It has been variously described that the sacroiliac joint receives its innervation from the ventral rami of L4 and L5, the superior gluteal nerve, and the dorsal rami of L5, S1, and S2, or that it is almost exclusively derived from the sacral dorsal rami. Even though the sacroiliac joint is a known putative source of low back and lower extremity pain, there are few findings that are pathognomonic of sacroiliac joint pain. The controlled diagnostic blocks utilizing the International Association for the Study of Pain (IASP) criteria demonstrated the prevalence of pain of sacroiliac joint origin in 19% to 30% of the patients suspected to have sacroiliac joint pain. Conservative management includes manual medicine techniques, pelvic stabilization exercises to allow dynamic postural control, and muscle balancing of the trunk and lower extremities. Interventional treatments include sacroiliac joint, intra-articular joint injections, radiofrequency neurotomy, prolotherapy, cryotherapy, and surgical treatment. The evidence for intra-articular injections and radiofrequency neurotomy has been shown to be limited in managing sacroiliac joint pain.

Imaging in lumbar spinal stenosis.

Lumbar spinal stenosis is a common condition seen in patients presenting to physicians who specialize in pain management or perform spine surgery. The designation of "spinal stenosis" without other qualifiers is vague and as such holds little practical value. Classifications have been created in order to more specifically describe the various etiologies as well as the site(s) of narrowing. For this purpose, diagnostic imaging studies are vital. These include myelography, computed tomography (CT), and magnetic resonance imaging (MRI). Each imaging modality has its own inherent advantages and limitations in demonstrating anatomical structures and how they may contribute to the stenotic process. Since proper treatment follows accurate identification of the pathology, it is important for physicians to have a sound understanding of normal and abnormal spinal elements as they are depicted on various imaging studies.

The fundamentals of musculoskeletal imaging.

Pain management physicians need to understand the basic diagnostic tools for their profession, including the major musculoskeletal imaging modalities for joint and muscle disorders. This article serves to review the indications and limitations for musculoskeletal imaging modalities with particular attention to how altered anatomy may reflect injury mechanisms.

Minimally invasive options to disc surgery.

Consumer consciousness, the evolution of non-operative specialties involved in pain management, a continuing trend toward outpatient versus inpatient procedures and cost concerns have all generated interest in minimally invasive options to spine surgery. Accompanying this movement are the aspirations of reduced convalescence, loss of functional limitations, lowered complications and diminished costs. Although new therapies offer future promise, there is currently a paucity of randomized controlled trials on these options. The following is a general review of several minimally invasive options to disc surgery.

Thoracic facet blocks: bent needle technique.

Thoracic posterior joints are putative pain generators; yet there is a paucity of information to assist the clinician in the diagnosis and treatment of dorsal spine pain. A safe and effective bent needle injection/arthrography technique is described which can assist in the diagnosis of some patients with thoracic zygapophyseal joint dysfunction.

Can the sacroiliac joint cause sciatica?

In this brief study we provide evidence that earlier and more recent findings pertaining to the anatomy and physiology of the sacroiliac joint suggest that dysfunction in this joint could, similar to a herniated lumbar disc, produce pain along the sciatic nerve. These observations might explain some of the cases of sciatica in which no disc pathology can be found.

Sacroiliac arthrograms and post-arthrography computerized tomography.

Sacroiliac joint (SIJ) injection and arthrography have been described, yet no study has specifically categorized the morphological characteristics of SIJ arthrograms versus post arthrogram computerized tomography (CT). Forty-three patients with a mean age of 33 years (range 20-48 years) and an equal male to female distribution were studied radiographically for SIJ pathology. A total of 74 SIJ injections were performed using Image-intensifier-control and a posterior-inferior approach. Symptom reproduction indicating a provocation positive outcome, was reported in 63.5% with a mean injected volume of contrast media of 1.08 cc (S.D. 0.29). SIJ findings were then classified and scored in each aspect of the SIJ capsule by plain film arthrography followed by post arthrogram CT (anterior, posterior, superior and inferior aspects of the capsule). There was a significant direct correlation between the plain film and CT arthrography findings in each category (Kendall correlation coefficients 0.63 - 0.99, p<0.01). In addition, there was a significant direct correlation between provocation positive outcomes and volume of contrast injected (Kendall correlation 0.25, p<0.01; ANOVA, p<0.03). Post arthrogram CT revealed significantly more positive anterior capsule findings compared to plain film arthrography (McNemar's test, p<0.04). Conversely, plain film arthrography noted more diverticula compared to post arthrogram CT (McNemer's test, p<0.01). These findings demonstrate that a detailed radiographic analysis of the SIJ capsule is reasonable by either plain film arthrography or post arthrogram CT, with excellent agreement between the two techniques. Further, each test has specific regional benefits that may be appreciated in certain cases.

Competitive figure skating injuries.

The nature, type and frequency of injuries occurring at a national figure skating competition were examined. Data was compiled from the medical history form of all 208 participants and the on-site evaluations of the 55 skaters who presented for treatment. Twenty-six percent of all the skaters were injured during the competition. Senior skaters accounted for more injuries than their junior counterparts. Pairs skaters appeared to be more susceptible to injury, incurring significantly more injuries than singles or dance skaters. As in other reports, injuries to the lower extremities predominated. Low back injury comprised 14.6% of all injuries. Thirty-five (64%) of the 55 injuries were exacerbations of a pre-existing injury and twenty (36%) were new ones. Most competitive figure skating injuries are of the overuse type, suggesting a need to evaluate predisposing factors and methods of rehabilitation.

Thoracolumbar syndrome in athletes.

The thoracolumbar syndrome is a potential cause of back pain in athletes whose sport involves prolonged posturing with the hips flexed and the head extended upward. This syndrome may be overlooked and athletes are sometimes inappropriately treated for an incidental finding in the lower lumbar spine disclosed on conventional imaging studies. The clinical presentation involves point tenderness over the affected motion segment (T12 through L3) with pain radiating along a segmental nerve distribution (anterior or posterior rami divisions) of thoracolumbar origin. Provocative injection of the posterior joints and/or discs under image-intensifier-control can provide a definitive diagnosis. Muscle balancing and stabilization exercises to counteract the postural inequities inherent to the sport usually allow for successful return to play.

Histologic analysis of neural elements in the human sacroiliac joint.

STUDY DESIGN: The posterior ligament of the human sacroiliac joint was examined for nerves and nerve endings using histologic and immunohistochemical techniques. OBJECTIVE: To identify nerve fibers and mechanoreceptors in the posterior ligament. SUMMARY OF BACKGROUND DATA: According to the findings of previous studies, the human sacroiliac joint receives myelinated and unmyelinated axons that presumably conduct pain and proprioceptive impulses derived from mechanoreceptors and free nerve endings in the human sacroiliac joint. METHODS: Tissue obtained from six patients was stained with gold chloride and that obtained from six additional patients was stained using antibodies specific for substance P and protein gene product 9.5. RESULTS: The staining of joint tissue using the gold chloride technique showed myelinated and unmyelinated nerve fibers, two morphotypes of paciniform encapsulated mechanoreceptors, and a single nonpaciniform mechanoreceptor. Analysis using immunohistochemical staining for protein gene product 9.5 did not unequivocally show axons, nerve fascicles, or mechanoreceptors. Similarly, analysis based on immunohistochemical staining for substance P, one of several neurotransmitters known to signal pain from the periphery, showed reactive elements that may have been nerves, but because of background staining, could not be positively identified as such. CONCLUSIONS: The presence of nerve fibers and mechanoreceptors in the sacroiliac ligament demonstrates that the central nervous system receives information, certainly proprioceptive, and possibly pain from the sacroiliac joint. Although it is not known how the central nervous system uses such information, it seems reasonable to speculate that the proprioceptive information is used to optimize upper body balance at this joint. In addition, because the staining techniques used generally to show nerves and nerve elements in periarticular connective tissue are nonspecific, the distinction between neural and nonneural should be made on the basis of both morphologic and staining characteristics.

Clinical evaluation of ankylosing spondylitis in Switzerland.

The purpose of this study was to identify the socioeconomic conditions and clinical history of ankylosing spondylitis patients in Switzerland. Data collected from 1177 ankylosing spondylitis patients, through a mail-in questionnaire, was analyzed for epidemiological factors, clinical presentation, musculoskeletal related surgical history and socioeconomic impact. The results showed that the sex ratio, average age at onset of symptoms, latent period until diagnosis, signs and symptoms, peripheral joint involvement and the prevalence of extraarticular organ affection of our patient group all conform with the majority of the published literature. Conversely, most reports suggest a higher frequency of musculoskeletal surgery, yet a lower employment capacity than the Swiss cohort. As described in other publications, aggressive physiotherapy appeared to be linked to a reduction in long-term disability, musculoskeletal deformities and surgical intervention. It was concluded that the present cohort of ankylosing spondylitis patients underwent fewer surgeries for musculoskeletal deformities and represented a lower socioeconomic burden (relative to disability and inability to work) than most patient populations previously studied.

An algorithm for understanding spine imaging.

The presentation of a patient with primary spine pathology may be confounded by a myriad of symptoms that span many organ systems. Likewise, imaging findings are often diverse and may be as subtle as slight posterior joint asymmetry combined with paravertebral myofascial strain or as goss as fracture-dislocation with neurological sequelae. A systematic approach to selecting and applying the appropriate imaging study combined with a careful clinical history and examination will insure a more accurate diagnosis and proper treatment. The biomechanics of injury and the pathophysiology of the disease process in question should always be considered. This review discussed an algorithmic approach for understanding spine imaging with discussions of radiography, radionuclide scan, myelography, computed tomography scanning and magnetic resonance imaging.

No clear winner in differing imaging modalities for cervical radiculopathy.

We review the literature pertaining to the strengths and limitation of myelography, computerized tomography (CT) and magnetic resonance imaging (MRI) relative to developing a diagnostic algorithm in the evaluation of cervical radiculopathy. To obtain the relevant literature, a Medline search was conducted using selected keywords and phrases. In addition, the bibliography of all retrieved articles was searched and pertinent articles were obtained and evaluated. The analysis revealed that developing a research based algorithm of imaging studies for the evaluation of cervical radiculopathy is not currently realistic. Furthermore, we found that most studies on the predictive value of imaging studies for cervical radiculopathy are outdated by more recent technology.

Current applications of electrotherapeutics in collagen healing.

Electrical current flow appears to be integral to the healing of collagen containing tissue, i.e., bone, cartilage, ligaments, tendons and skin. Accordingly, it is reasonable to hypothesize that externally applied electrical fields should be able to enhance healing, especially in conditions that have resisted more standard treatments. Nevertheless, applications of electrotherapeutics is challenging because the precise mechanism of action is unknown and, accordingly, there is an almost unlimited combination of stimulation parameters (e.g., type of waveform, voltage, current, phase, frequency, etc.) that can be applied to a treatment site. Presently, of the three major types of electrical stimulation, i.e., direct, and capacitive and inductive coupling, there is a growing trend toward utilization of the latter because of its efficacy and greater margin of safety. Although the mechanisms of action for enhanced healing of all three types remain elusive there is increasing evidence that electrical stimulation exerts its influence via effects at the cellular and/or molecular levels within the tissue. Utilization of electrotherapeutics has been most prevalent in bony injuries resistant to healing, but applications to severe lesions of skin and ligaments, and even to degenerative joint disease seems promising as cartilage has been shown to be more responsive than bone to applied electrical energy. We conclude that there is a clear trend toward greater orthopedic utilization of inductive stimulation and that, despite the lack of definitive guidelines relating specific parameters with specific conditions, electrotherapeutics appears to be a safe and often effective treatment for collagen containing tissues in many cases in which more standard therapies have failed.