F. Todd Wetzel

Early Radiographic and Clinical Results of Balloon Kyphoplasty for the Treatment of Osteoporotic Vertebral Compression Fractures

Study Design. A prospective consecutive cohort study of clinical and radiographic outcomes after kyphoplasty for treatment of osteoporotic vertebral compression fractures. Objectives. To measure changes in spinal deformity, activity level, and pain after kyphoplasty treatment. Summary of Background Data. Pain and kyphosis caused by osteoporotic vertebral compression fractures adversely affect quality of life and survival. Kyphoplasty involves the inflation of a balloon bone tamp, percutaneously placed in a fractured vertebral body, followed by deposition of bone cement into the resulting cavity. Previous reports indicate that kyphoplasty improves patient function and restores height of collapsed vertebral bodies, but limited data about the effects of kyphoplasty on spinal sagittal alignment are available. Methods. Twenty-nine patients with osteoporotic vertebral compression fractures who did not respond to medical therapy were treated by kyphoplasty. These patients underwent 37 operations to treat 61 vertebral compression fractures between T6 and L5. Sagittal alignment was analyzed from standing radiographs (pre- and postkyphoplasty). Patient surveys were used to assess pain relief, improvement in activity, and satisfaction with the surgical procedure. Results. In this cohort, a mean of 8.8° (range 0–29°) of correction of local spinal kyphosis was achieved with kyphoplasty. Thirty of 52 fractures (17 patients) were considered reducible and had >5° of correction, with a mean improvement in sagittal alignment of this population of 14.2°. Patient surveys revealed significant pain reduction within the first week after surgery and improved activity levels for a majority of patients. Conclusions. Kyphoplasty improves physical function, reduces pain, and may correct kyphotic deformity associated with vertebral compression fractures.

General principles of diagnostic testing as related to painful lumbar spine disorders

Study Design. The literature on diagnostic tests available to the spine clinician for the evaluation of chronic low back pain was reviewed. Objectives. To review critically the available information and data on invasive diagnostic tests used for evaluation of chronic low back pain. Summary of Background Information. Numerous published studies have described the technique and clinical results of diagnostic blocks for chronic low back pain. There are various methodologies, but most lack of an adequate “gold standard” with which to compare the results of the diagnostic test. Methods. The available published studies of diagnostic tests commonly used in the evaluation of chronic low back pain were reviewed, with a focus on invasive techniques. The techniques were evaluated on the basis of the data available to support the conclusions that could be drawn for each of these techniques. The principles of diagnostic testing, including specificity and sensitivity, were reviewed and applied in the context of the data available for each of these invasive tests. Results. The essential features the clinician seeks in a diagnostic test are accuracy, safety, and reproducibility. It is essential to have a gold standard with which to compare the accuracy of a given diagnostic test. There is no completely reliable gold standard with which to compare a diagnostic test (or injection) when the absence of pain is the end point. The clinical setting in which the test is used directly affects the test results. The prevalence of the disease therefore affects the meaningfulness of the test results. Imaging studies have their greatest value in the exclusion of other conditions. These studies alone were not adequate for predicting the patients who would respond to controlled diagnostic blocks of the facet joint. Facet joint diagnostic blockade probably is most accurately performed by median nerve branch block. The greatest specificity for a positive response to a facet denervation procedure is achieved when the diagnosis is established via highly controlled anesthetic blocks. Over the past few decades, the sacroiliac joint has received varying degrees of interest as an important pain generator of low back pain. Despite testimonials to the contrary, no diagnostic physical examination has correlated with sufficient specificity to diagnose this condition reliably from a clinical standpoint. Lumbar discography has been one of the single most controversial subjects in the management of degenerative, painful lumbar spine conditions. The specificity and sensitivity are high for the diagnosis of disc degeneration. The question that revolves around discography concerns the accuracy of this test for the diagnosis of discogenic pain. An integral part of the problem is the lack of an adequate gold standard. In a comparison of nerve root blockade, sciatic nerve block, posterior ramus block, and subcutaneous injection in a cohort of patients with sciatica, the sensitivity of nerve root block was very high, with only a moderate level of specificity. In the case of diagnostic selective nerve blocks used for evaluation of complex or protean nerve compression, surgical confirmation and clinical results should be a reliable gold standard. Conflicting results have been presented depending on the target lesion and method of study. Conclusions. There are inherent limitations in the accuracy of all diagnostic tests. The tests used to diagnose the source of a patient’s chronic low back pain require accurate determination of the abolition or reproduction of the patient’s painful symptoms.

A Prospective, Randomized, Double-Blind Study Evaluating the Efficacy of Postoperative Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site After Spinal Arthrodesis

Study Design. Parallel design, prospective, double-blind, randomized, controlled trial composed of two independent groups treated with a continuous infusion catheter (saline vs. Marcaine) placed into the iliac crest bone graft (ICBG) site. Objective. To determine the effects of postoperative continuous local anesthetic agent infusion at the ICBG harvest site in reducing pain, narcotic demand and usage, and improving early postoperative function after spinal fusion. Summary of Background Data. Harvesting iliac crest bone has been shown to be a source of pain and morbidity. Long-term patient complaints may be more closely associated with the procurement of the iliac crest graft rather than the primary surgical site. Methods. Thirty-seven patients were enrolled in a prospective, randomized, double-blind parallel-designed study after informed consent and IRB approval was obtained. Twenty-eight patients had ICBG harvested for lumbar arthrodesis and nine for cervical arthrodesis. During spinal arthrodesis surgery, patients were randomly assigned to receive 96 mL (2 mL/hr × 48 hours) of either normal saline (control group, n = 22) or 0.5% Marcaine (treatment group, n = 15) delivered via a continuous infusion catheter placed at the ICBG harvest site. All patients received Dilaudid PCA after surgery. Pain scores, narcotic use/frequency, activity level, and length of stay (LOS) were recorded. Physicians, patients, nursing staff, and statisticians were blinded to the treatment. Results. Mean patient age was 60 years and similar between groups. Narcotic dosage, demand frequency, and mean VAS pain score were significantly less in the treatment (Marcaine) group at 24 and 48 hours (P < 0.05). The average LOS was 4.1 days with no difference between Marcaine or control groups. No complications were attributed to the infusion-catheter system. Conclusions. Continuous infusion of 0.5% Marcaine at the ICBG harvest site reduced postoperative parenteral narcotic usage by 50% and decreased overall pain scores. No complications were attributed to the infusion-catheter system. The use of continuous local anesthetic infusion at the iliac crest may help in alleviating acute graft-related pain, hastening patient recovery and improving short-term satisfaction.

Chronic pain of spinal origin

The cost of chronic benign spinal pain is large and growing. The costs of interventional treatment for spinal pain were at a minimum of

Neuraxial medication delivery

13 billion (U.S. dollars) in 1990, and the costs are growing at least 7% per year. Medical treatment of chronic pain costs

Treatment of Chronic Pain in Failed Back Surgery Patients with Spinal Cord Stimulation: a Review of Current Literature and Proposal for Future Investigation

9000 to

Chronic benign cervical pain syndromes. Surgical considerations.

19,000 per person per year. The costs of interventional therapy is calculated. Methods of evaluating differential treatments in terms of costs are described. Cost-minimization versus cost-effectiveness approaches are described. Spinal cord stimulation and intraspinal drug infusion systems are alternatives that can be justified on a cost basis. Cost minimization analysis suggests that epidural injections under fluoroscopy may not be justified by the current literature.

Management of metastatic disease of the spine.

Study Design. A literature review and synthesis were performed. Objective. To summarize the history, use, and innovation related to neuraxial drug delivery for the treatment of intractable back pain. Summary of Background Data. The discovery of opioid receptors in the early 1970s provided a rational basis for the delivery of opioid drugs intraspinally. Epidural or intrathecal infusions deliver drugs directly to opioid receptors, limit systemic exposure, and by decreasing the opioid dosage required for pain relief, generally reduce side effects. The benefits of short-term spinal analgesia led to investigation of longer-term continuous subarachnoid opioid infusions for the management of both cancer pain and noncancer pain, such as that of spinal origin. Methods. 650 650 650 Results. Unique features of this article include an updated pain continuum, updated indications for intrathecal therapy, a detailed comparison of trial techniques, a detailed comparison of the advantages of different types of pumps, a synopsis of troubleshooting for inadequate efficacy, and an updated statement regarding intrathecal pumps and radiologic procedures, including MRI scanning. Some challenges remain. Large-scale well-controlled studies could answer some perplexing questions regarding efficacy in patients with noncancer or neuropathic pain. Patient selection criteria undoubtedly will be refined and validated as more patients are treated. In addition, further investigation of specifically targeted medications or drug combinations for intraspinal use could increase efficacy, reduce side effects, and expand indications. Conclusions. Intraspinal medication delivery has become an effective technique for control of intractable pain in appropriately selected patients seen by spine surgeons.

Managing chronic pain of spinal origin after lumbar surgery

Objective. The authors attempted to design and conduct a randomized, prospective study to investigate the efficacy of spinal cord stimulation (SCS) for patients with chronic back and leg pain following at least one previous surgery. While the scientific advantages of the randomized, prospective trial are considerable, the authors encountered numerous practical and ethical difficulties with conducting these trials.

Treatment of Chronic Discogenic Low Back Pain With Intradiskal Electrothermal Therapy

The results of surgical intervention for chronic benign pain syndromes are generally poor. In this review, pertinent ablative and modulatory techniques are reviewed, with specific reference to their utility for benign pain syndromes. With the possible exception of facet rhizotomy, the ablative modalities have little role in the management of benign pain syndromes. The more extensive techniques of cordotomy, dorsal root entry zone lesioning, ganglionectomy, and rhizotomy, have erratic results and high rates of complication. No long-term studies exist to support the use of facet rhizotomy. It is minimally invasive, however, and has little morbidity. In patients with benign refractory posterior column pain, facet rhizotomy may be worth consideration. Modulatory devices may have a role in benign pain syndromes. While the use of indwelling epidural catheters remains investigational, dorsal column stimulation has been widely studied. In representative reports, significant pain relief has been observed in up to 60% of patients (mean follow-up of two years).47In the carefully selected patient, this may represent a valuable therapeutic adjunct.