Ken Hsu

Response to steroid and duration of radicular pain as predictors of surgical outcome.

Prolonged structural compromise of spinal nerve roots can lead to chronic changes that surgical decompression might not be able to reverse. In this study, it was hypothesized that if there were a reversible structural pain component, a steroid injected into the patients symptomatic nerve root should provide temporary pain relief and that these patients should have a favorable surgical outcome. It also was hypothesized that duration of radicular symptoms would correlate inversely with surgical outcome. For postoperative relief of radicular pain, the results showed that patients with pain lasting less than 1 year had a positive surgical result (89%), regardless of response to steroid. Patients with pain lasting more than 1 year and who have had a positive response to steroid injected into the symptomatic nerve root (roots) had a positive surgical outcome of 85%. Patients who did not respond to the steroid and had pain for more than 1 year (95%) generally had a poor surgical outcome. Although the poor outcome in the last group might be explained in some cases by an inadequate structural correction, inadequate stabilization, or functional reasons, the majority of these failures represented irreversible changes in the neural structures.

Clinical efficacy of spinal instrumentation in lumbar degenerative disc disease.

In review of 871 lumbar fusion procedures performed during the last 8 years, the theoretical advantages of lumbar spinal instrumentation are not borne out in simple discogenic disease. Four groups of 30–35 patients without previous surgery who underwent fusion by different techniques were matched for age, sex, length of follow-up, surgeons, number of levels fused, duration of prcoperative symptems, diagnosis, and type of third party payer. At least for the diagnoses of herniated disc with segmental instability and the instrumentation systems used in this study, results were superior with no internal fixation. This is in keeping with the higher complication rates and frequent need for implant removal reported by many authers.

Early results of spinal fusion using variable spine plating system

Seventy-seven consecutive patients underwent application of variable spine plating (VSP) spinal plates between August 1984 and October 1985. Sixty-four percent had previous procedures at the same level or levels operated. Operative Indications were spinal stenosis, segmental instability, unstable spondylolisthesis, herniated disc with instability, pseudarthrosis, unstable fracture, and failed surgery syndrome with evidence of one of the preceding. Overall results showed 30% excellent, 30% good, 34% fair, 6% poor. There were four deep wound infections and 19 patients with one or more broken screws. Screw alignment and the angular relationship of each screw to the spinal plate are considered important technical factors in minimizing screw failure. Vigorous distraction of the vertebrae using interpedicular screws is rarely indicated. Twenty-four patients required reoperation. We feel the procedure is relatively indicated in cases of moderate to severe instability, such as some cases of spondylolisthesis, failed surgery with marked segmental instability, the obese, deconditioned patient, or cases of spinal stenosis rendered very unstable by surgical decompression, and most strongly indicated in unstable lumbar and thoracolumbar fractures.

Normal magnetic resonance imaging with abnormal discography

In degenerative lumbar spine disease, recent studies have supported the clinical usefulness of discography, especially when used with computed tomography (CT) scanning. The role and capabilities of magnetic resonance imaging (MRI) scanning are currently evolving and being defined. This study reviews a series of patients with prolonged disabling symptoms who had normal MRI scans and abnormal discography. Discograms and discogram-CT scans may at times allow detection of clinically correlative and significant pathology (usually annular disruptions) not suggested by MRI scanning. This fact should be considered in patients with normal MRI scanning and continuing unexplained symptomatology.

High lumbar disc degeneration. Incidence and etiology.

Three hundred seventy-nine consecutive magnetic resonance images (MRIs) with dual-echo images of the entire lumbar spine were reviewed by the authors. All 379 patients presented with back pain and/or leg pain; they were interviewed and examined. Pain drawings were completed by all. There were 42 patients (11.1 %) with disc pathologies involving T12–L1, L1–2, and/or L2–3 levels. Six patients (1.6%) had isolated disc degeneration and/or herniations limited only to these high lumbar segments. The remaining 36 patients had degenerative changes of the higher discs with variable involvement of the lower lumbar discs. Out of 12 spondylolistheses of L5 on S1,7 had high disc pathologies at one or more levels presenting as skipped lesions; more severe high disc lesions were noted in Grade II slips. Isolated high disc degeneration is often associated with pre-existing abnormalities such as end-plate defects, Scheuermanns disease, limbus vertebra, and so forth, and stressful cumulative work activities such as in construction workers, airplane mechanics, and so forth. High disc degeneration was noted above or below previous fractures. High disc involvement with diffuse changes in lower lumbar spine was more commonly found in ascending fashion in older age groups, and in patients who have had previous lower lumbar spine surgeries, prior fusions in particular. Our findings suggest that altered mechanics are associated with the high lumbar disc pathologies.

DIPTHEROIDS AND ASSOCIATED INFECTIONS AS A CAUSE OF FAILED INSTRUMENT STABILIZATION PROCEDURES IN THE LUMBAR SPINE

Between February 1985 and October 1987, the authors identified seven patients with occult lumbar spine infections associated with the presence of spinal fixation hardware. Six of these infections were with organisms of low virulence; four of the seven patients had polymicrobial infections. All of the polymicrobial infections contained a Diptheroid as one of the isolates. Two of the seven patients studied had normal sedimentation rates. All had white blood cell counts less than 12,000 cells. Imaging studies were not helpful with the exception of one case with a positive gallium scan. The diagnoses were supported by clinical presentation, pathologic tissue changes, positive cultures, and response to therapy. Successful therapy was obtained by removal of hardware and treatment with antibiotics.

Occult infections causing persistent low-back pain

Occult infections caused by indolent organisms may produce persistent back pain that may be difficult to diagnose. The usual findings considered indicative of spinal infection are not reliable in these cases. The authors describe nine patients who presented with occult infections of the lumbar spine. Two of the nine had no antecedent lumbar surgeries nor open wounds. The predominant organisms were diptheroids and coagulasenegatlve staphylococci. The diagnosis was established by the clinical course, pathologic tissue changes at surgery, cultures, and response to antibiotic therapy. Normal Westergren sedimentation rates were noted in seven of nine patients, and normal white blood cell counts in six of nine patients. With the exception of two positive computed tomography (CT) scans, one positive gallium scan, and one positive magnetic resonance imaging (MRI) scan, all remaining imaging studies were negative for infection. In many cases, the infection neither was limited to nor involved the disc space.

Metabolic bone disease in lumbar pseudarthrosis

Pseudarthrosis occurs in many patients who undergo lumbar spine fusion and it has been suggested that abnormalities of bone metabolism contribute to it. The authors evaluated 47 patients with pseudarthrosis for metabolic bone disease. Symptomatic patients with pseudarthrosis underwent metabolic bone evaluation. Abnormal results of laboratory tests were found in 7 patients (14.9%): 3 low or borderline 1,25 dihydroxy vitamin D3,2 elevated 24-hour urine calcium, and 2 low serum testosterone. None of these abnormalities correlated with other clinical findings. Bone density was low in 14 of 24 patients in whom it was measured. Low values did not correlate with smoking or abnormal laboratory values. Metabolic bone abnormalities do not appear to play a frequent or significant role in pseudarthrosis after attempted lumbar spine fusion.

Treatment of facet cysts associated with neurogenic intermittent claudication with x-stop.

Background: Facet degeneration often leads to the formation of synovial facet cysts. As facet cysts invade the spinal canal, they become a contributing factor to spinal stenosis. Previous studies have demonstrated successful treatment of neurogenic intermittent claudication (NIC), a major symptom of spinal stenosis, with an interspinous process device. Purpose: To compare clinical outcomes of patients with and without synovial facet cysts treated with an interspinous process device. Study Design: Retrospective review of prospective data of consecutive patients undergoing the X-Stop procedure at an institution. Outcome Measures: Visual Analog Scale; Oswestry Disability Index; sitting, standing, and walking tolerances; and satisfaction survey. Methods: Review of all patients from 2006 to 2010 undergoing X-Stop procedure at an institution. Imaging studies were used to identify the presence and measure the size of the facet cysts in 285 patients with a minimum of 6-month follow-up. Comparative clinical outcomes determined if X-Stop is a successful treatment option for patients with NIC in conjunction with synovial facet cysts (<3 mm, ≥3 mm). Results: Fifty-eight of 285 patients (20.4%) were determined to have a synovial cyst as a contributing component of spinal stenosis. Twelve of 58 patients were noted to have a cyst ≥3 mm. The mean follow-up time for patients with and without a facet cyst was 21 months (6–55±12 mo) and 22 months (6–61±12 mo), respectively. The age of the patient at the time of the operation with and without facet cysts was 73 (±10 y). Patients without synovial cysts, with synovial cysts, and cysts ≥3 mm had an average change in Oswestry Disability Index of 15.6, 15.8, and 16.2, respectively. Visual Analog Scale scores were 2.3, 1.8, and 2.3, respectively. In addition, on satisfaction surveys 72.4%, 82.0%, and 77.8% were either very or somewhat satisfied, respectively. Overall complications included 4 spinous process fracture, 4 hematomas, 1 wound infection, and 1 implant migration. Conclusions: No statistical difference was noted in any of the outcome measures among patients with small facet cysts, large facet cysts, or without facet cysts when treated with an interspinous process device. We can thus conclude that X-Stop is an appropriate treatment consideration for NIC with or without the presence of synovial facet cysts.

Lumbosacral Fusions with Harrington Rods and Intersegmental Wiring

Harrington rods are a valuable adjunct for fusion of the lumbosacral spine. Major limits of distractions are achieved with these rods. Greater amounts of decompression are possible. Decompression, alignment, and stability are maintained. Intersegmental wiring increases security and eliminates the problem of hook and rod displacement and loss of lumbar lordosis. A variety of methods are available for sacral fixation to avoid neurologic complications from the distal hooks. Three- and four-level Harrington rod distraction lumbosacral fusions have proven to be successful in returning severely-disabled spinal stenotic, obese, and osteoporotic patients to normal activities.