The role of calcium deposition in the ligamentum flavum causing a cauda equina syndrome and lumbar radiculopathy

Histological difference in ligament flavum between degenerative lumbar canal stenosis and non-stenotic group: A prospective, comparative study

BACKGROUND

Ligament flavum (LF) hypertropy is the main etiopathogenesis of lumbar canal stenosis (LCS). The purely elastic LF undergoes a morphological adaptation including a reduction in the elastic fibers and a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. However, the morphometric analysis can delineate the LF in patients with LCS from those without LCS, which would help in better understanding LCS pathogenesis.

AIM

To compare the histopathological changes in LF between the degenerative LCS and non-stenotic (non-LCS) group.

METHODS

The present prospective study was conducted in 82 patients who were divided into two groups, namely LCS and non-LCS. Demographic details of the patients such as duration of symptoms, level of involvement, and number of segments were recorded. The LF obtained from both groups was histopathologically examined for the fibrosis score, elastic fiber degeneration, calcification, and chondroid metaplasia. Morphometrical details included a change in elastin and collagen percentages, elastin/collagen ratio, elastic fiber fragmentation, and ligamentocyte numbers. All parameters were compared between the two groups by using the independent t test, Chi-square test, and Pearson’s correlation test.

RESULTS

Out of 82 cases, 74 were analysed, 34 in LCS and 40 in non-LCS group. The mean ± SD age of presentation in LCS and non- LCS group was 49.2 ± 8.9 and 43.1 ± 14.3 respectively. The LCS group (n = 34) exhibited significant differences in fibrosis (P = 0.002), elastic fiber degeneration (P = 0.01), % elastic fragmentation (66.5 ± 16.3 vs 29.5 ± 16.9), % elastic, content (26.9 ± 6.7 vs 34.7 ± 8.4), % collagen content (63.6 ± 10.4 vs 54.9 ± 6.4), reduction of elastic/collagen (0.4 ± 0.1 vs 0.6 ± 0.1), and ligamentocyte number (39.1 ± 19.1 vs 53.5 ± 26.9) as compared to non-LCS group (n = 40). The calcification (P = 0.08) and Pearson’s correlation between duration and loss of elastin was not significant. The difference in LF morphology is consistent in patient’s ≥ 40 years of age among the groups as found in subgroup analysis. Similarly in the patents < 40 and > 40 in the non-LCS group.

CONCLUSION

LF is vital in the pathogenesis of LCS. The purely elastic LF undergoes a morphological adaptation that includes a reduction in the elastic fibers with a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. The present study provides a detailed morphometric analysis to semiquantitatively delineate the LF changes in patients with LCS from those in patients without LCS.

Morphological Changes in the Ligamentum Flavum in Degenerative Lumbar Canal Stenosis: A Prospective, Comparative Study

Study Design

Prospective, comparative.

Purpose

To compare the histopathological and electron microscopic changes in the ligamentum flavum (LF) between degenerative lumbar canal stenosis (LCS) and lumbar disk herniation (LDH).

Overview of Literature

The LF has been implicated as a key structure in the pathogenesis of LCS. With aging, the LF undergoes morphological changes–a decrease in the elastic component and an increase in the collagen component, in addition to other focal changes. By comparing the histopathological and electron microscopic picture of the LF in elderly patients with LCS with that in young patients with LDH, the role of this ligament in the pathogenesis of LCS may be clarified.

Methods

Forty patients were prospectively recruited and divided into two groups: group 1 included 20 patients with degenerative LCS aged >55 years and group 2 included patients with LDH aged <35 years. The ligament flava were collected during the patients’ surgery. The features noted on histopathological examination included the fibrosis score, the loss of elastic fibers, calcification, chondroid metaplasia, mucinous degeneration, vascularization, long septa, clefts, granulation tissue, and ganglion-like cysts. The features noted on electron microscopic examination included the elastic fiber thickness, the quality of elastic fibers, the elastic:collagen ratio, calcification, melanin fibers, remnants of necrotic cells, and electron-dense material in the LF. All parameters were compared between group 1 and group 2.

Results

On histopathological examination, the two groups exhibited significant differences regarding three parameters: chondroid metaplasia, long septa, and ganglion-like cysts. On electron microscopy examination, significant differences were observed between the two groups regarding two parameters: the quality of elastic fibers and the elastic:collagen ratio.

Conclusions

Characteristic morphological changes may be noted on histopathological and electron microscopic examination that mark the degenerative changes in the LF that contribute to the occurrence and pathogenesis of degenerative LCS.

Acute lumbar spinal pseudogout attack after instrumented surgery

STUDY DESIGN

A case report.

OBJECTIVE

An elderly patient presented with an acute lumbar spinal pseudogout attack after lumbar instrumented surgery.

SUMMARY OF BACKGROUND DATA

Although gout and pseudogout are common diseases causing inflammatory arthropathy in peripheral joints, involvement of the spine is uncommon. Here, we report a patient experiencing an acute lumbar spinal pseudogout attack after lumbar instrumented surgery.

METHODS

The patient was treated for lumbar spondylolisthesis at L4 and L5 level and afterward complained of lower back and bilateral leg pain. Conservative treatment was not effective for the patient; therefore, we preformed posterior transforaminal lumbar interbody fusion surgery.

RESULTS

The postoperative course was uneventful; however, he experienced lower back pain 4 weeks after surgery. Magnetic resonance image showed changes in signal intensities of vertebra and fluid accumulation in posterior back muscles. A biopsy was performed, but the culture was negative for infection. Calcium pyrophosphate dehydrate was detected in the fluid. Thus, conservative therapy without antibiotics was performed, and the patient's symptoms disappeared within 2 weeks.

CONCLUSION

Here, we reported the first case of acute lumbar spinal pseudogout attack after lumbar instrumented surgery. We recommend considering pseudogout before and after surgery.

Recurrent acute low back pain secondary to lumbar epidural calcification

INTRODUCTION

Epidural calcification is a rare cause of back pain, and spontaneous epidural calcification has not been reported previously.

CASE REPORT

We describe a patient with acute low back pain and signs of lumbar nerve root compression due to epidural calcification, as demonstrated by CT-scan and MRI. Radiological signs of spondylodiscitis led to a search for an infectious cause, which was negative, and her symptoms responded rapidly to NSAID treatment alone. Her symptoms recurred 18 months later, and further imaging studies again revealed epidural calcification, but with a changed distribution. Her symptoms were relieved once more by NSAID treatment alone.

DISCUSSION

We propose that epidural calcification secondary to aseptic spondylodiscitis is the main cause of acute back pain in this patient. A possible mechanism may be the pro-inflammatory effects of calcium pyrophosphate or hydroxyapatite crystal deposition within the epidural space.

Crystal arthropathy of the lumbar spine: a report of 4 cases

Gout or pseudogout, caused by deposition of crystals, rarely affects the spine. We report 4 cases with gout or pseudogout in the lumbar spine. Two had cauda equina syndrome and another 2 had spinal stenosis. To avoid unnecessary surgery, this should be considered in the differential diagnosis when treating patients with histories of gout or pseudogout for spinal problems.

Recurrent back pain and fevers

An elderly woman presented with her third episode of back pain, fever and neurological deficits. She subsequently developed pseudogout of the knee, and a diagnosis was made of systemic calcium pyrophosphate deposition disease (CPPD) involving the spine and causing intermittent cauda equina syndrome. This case illustrates the difficulty of differentiating infection from CPPD.

Calcium pyrophosphate deposition disease mimicking polymyalgia rheumatica: A prospective followup study of predictive factors for this condition in patients presenting with polymyalgia symptoms

OBJECTIVE

To assess the characteristics of calcium pyrophosphate deposition disease (CPDD) with proximal involvement mimicking polymyalgia rheumatica (PMR), and to identify the best predictive factors for the presence of a clinical pattern of CPDD in patients presenting with polymyalgia symptoms.

METHODS

Patients diagnosed with either PMR or CPDD at the Rheumatology Division of Hospital Meixoeiro (Vigo, Spain) over a 7-year period (1997-2003) were prospectively followed for at least 12 months.

RESULTS

The study group comprised 118 patients with PMR features and 112 patients with CPDD. Eighty-two of the 118 patients with PMR manifestations were diagnosed as having pure PMR, and 36 met the diagnostic criteria for both PMR and CPDD. Patients with CPDD mimicking PMR were older (P = 0.02) and had peripheral arthritis more frequently (P = 0.004) than those with pure PMR. Radiologic osteoarthritic changes in the hands and knees, including more advanced radiologic grade of knee osteoarthritis, and tendinous calcifications were more frequent in patients with PMR/CPDD (P < 0.001). The best predictive factors for the occurrence of this atypical pattern of CPDD in a patient presenting with PMR features were the age at diagnosis and the presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis.

CONCLUSION

Involvement of proximal joints may be the clinical presentation of CPDD. CPDD should be included in the spectrum of diseases mimicking PMR. The presence of tibiofemoral osteoarthritis, tendinous calcifications, and ankle arthritis are clues that may alert the clinician to the presence of CPDD in an elderly patient presenting with PMR manifestations.

The pathology of ligamentum flavum in degenerative lumbar disease

STUDY DESIGN

A pathologic study of the ligamentum flavum in degenerative lumbar disease.

OBJECTIVES

To elucidate the clinical significance of each pathologic finding of the ligamentum flavum.

SUMMARY OF BACKGROUND DATA

In many reports, researchers observed the ligamentum flavum removed partially during surgery and did not evaluate the whole image of the ligamentum flavum. In addition, there are only a few reports that examined the possible association between various histologic findings and clinical findings. And, thus, there are many unclear points in the clinical significance indicated by each pathologic finding.

METHODS

The study participants were 50 patients with degenerative lumbar diseases who underwent surgical decompression with removal of the ligamentum flavum of the affected spinal level. Tissue specimens of the removed ligamentum flavum in cross section were prepared, and changes in the elastic fibers and collagen fibers were evaluated in three grades to evaluate the whole image. In addition, we observed the presence or absence of any focal lesions and statistically analyzed the possible association between these histologic findings and clinical symptoms or image findings.

RESULTS

In regard to the association between histologic findings and clinical symptoms or image findings, calcification was observed in significantly older patients, who tended to have low scores in preoperative JOA score, and was frequently observed in patients with cauda equina symptoms. Patients with ossification had a significantly greater % slip, and chondroid cells were frequently observed in patients with spondylolisthesis.

CONCLUSION

Various pathologic findings provided important foundations for discussing the pathogenesis of lesions in ligamentum flavum. Calcification was frequently observed in elderly patients and those with cauda equina symptoms, and these patients tended to have severer preoperative symptoms. Chondroid cells were frequently observed in patients with spondylolisthesis, and patients with ossification had a greater % slip, suggesting involvement of mechanical load in ossification of ligaments. The pathologic findings were significantly related to the clinical features, and these findings will be profitable for understanding the pathogenesis of degenerative lumbar disease.