Osteophytes: The product of convergent evolution.

The very reasonable suggestion, that diarthrodial joint and juxta-discal (vertebral centra-marginal) bony overgrowths (referred to as osteophytes) have different etiologies, has eluded previous confirmation. The prevailing perspective is that diarthrodial osteophytes represent the product of compressive forces and that those on the margins of vertebral centra result from traction and therefore are enthesial in derivation. If diarthrodial joint osteophytes result from intrinsic pressures, any surface responses would require transcortical nutritional support, easily recognized by en face microscopic examination. This contrasts with enthesially derived growth, the surface of which is characterized by Sharpey's fiber insertions. These are recognized as inverted cones with a central protrusion on examination of related bone surfaces. We hypothesize that diarthrodial and disc-adjacent osteophytes have a different pathophysiology, distinguishable on the basis of microscopic surface appearance. We pursued microscopic examination of the surfaces of osteophytes present on diarthrodial joints (hip, knee, elbow, costovertebral) and vertebrae (cervical, thoracic, and lumbar) from the CAL Milano Cemetery Skeletal Collection for presence of transcortical channels and the inverted cones of Sharpey's fiber insertions. Examination of 22 diarthrodial joint osteophytes reveals the presence solely of transcortical channels, while examination of 35 vertebral centra marginal osteophytes reveals the presence only of inverted cones. Findings are independent of age, gender, joint affected, position in the spinal column and osteophyte "severity." It is now evidenced that all osteophytes are not created equal. Diarthrodial joint osteophytes are endochondrally derived; vertebral centra osteophytes, enthesial in derivation. Different pathophysiology at least partially explain the clinical character of these processes.

Forestier's syndrome : a rare cause of dysphagia. A case report and review of the literature.

We report a 72-year-old male with Forestier's syndrome suffering of dysphagia due to an anterior cervical calcification, unusually great in both volume and extent. Its resection by anterior approach allowed the immediate restoration of a normal swallowing. A bony resection is sufficient in case of Forestier's syndrome, but it must be associated with fixation in case of degenerative osteophyte with disc instability. Long-term follow-up is necessary because the recurrence of the calcification is slow but frequent.

Relationship between spinal osteoarthritis and vertebral fractures in men older than 50 years: data from the Camargo Cohort Study.

Spinal osteoarthritis has been suggested as a risk factor for vertebral fractures. However, results are conflicting: most of the data are focused on the lumbar region, and referred to postmenopausal women, whereas data for men are scarce. The aim of this study is to assess the relationship between spinal osteoarthritis and vertebral fractures in men over 50 years of age. We conducted a cross-sectional study, nested in a prospective population-based cohort, including 507 community-dwelling men, 93 of them with at least one vertebral fracture. Vertebral fractures, osteophytosis, and disc space narrowing (DSN) were assessed by lateral thoracic and lumbar radiographs. Anthropometric, clinical, and densitometric variables were also analyzed. A multiple logistic regression model was performed. Eighty-five percent of vertebral fractures were located at the thoracic spine. Osteophytosis and DSN showed a bimodal distribution, with major frequency peaks at mid- and distal lumbar spine. The three distributions overlapped around the T9 vertebra. We did not find any relationship between lumbar osteoarthritis and vertebral fractures. Nevertheless, thoracic osteophytosis (OR, 1.84; 95 % CI, 1.05-3.17; p = 0.03) and DSN (OR, 2.52; 95 % CI, 1.43-4.46; p = 0.001) were found to be independently associated with prevalent vertebral fractures, after adjusting for confounders. Our results suggest a positive relationship between radiologic osteoarthritic changes at the thoracic spine and prevalent vertebral fractures in men more than 50 years of age. Osteoarthritis may act as a local risk factor, in addition to other mechanical factors, resulting in a greater propensity to fracture, especially at the mid-thoracic region.

Age-related changes in osteometry, bone mineral density and osteophytosis of the lumbar vertebrae in Japanese macaques.

The age-related changes in lumbar vertebrae were studied in 77 young/full adult Japanese macaques (Macaca fuscata) (40 females, 37 males), in terms of their morphometry, density and osteophytosis, and the interrelationship between these three aspects. The most common age-related pattern of morphometric changes was an initial increase during young adulthood until reaching the peak and then a subsequent decrease with age. Most of the peaks were in the age group 15-20 and 10-15 years in females and males, respectively. In both sexes, the age-related decrease in the vertebral body depth (ventro-dorsal) was greater than in the height and width. The ventral height of the vertebral body relative to the dorsal height continuously decreased with age. The trabecular bone mineral density (BMD) continuously decreased after young adulthood. However, the magnitude of the decreased trabecular BMD with age was greater in females than in males, especially in the older age groups. Osteophytosis clearly increased with age in both sexes, but males showed an earlier appearance of osteophytes and females tended to have more severe osteophytes from 15 years old upwards. A correlation between the osteometry, density, and osteophytosis severity appeared in all vertebrae, but not all of these reached statistical significance after controlling for the influence of age. Although Japanese macaques showed the higher prevalence and rapid increase of osteophytosis, a similar age change profile was observed in the lumbar vertebrae of Japanese macaques and humans.

The predictors of development of new syndesmophytes in female patients with ankylosing spondylitis.

OBJECTIVES: The formation of spinal syndesmophytes is an important outcome measure in ankylosing spondylitis (AS) but the predictors of new syndesmophyte development in female AS patients are unknown. This longitudinal study aimed to assess the rate and predictors of development of new syndesmophytes over a 2-year period in female AS patients. METHOD: Clinical and radiographic data were collected at baseline and after 2 years in 67 female AS patients. Spinal radiographs were scored using the Stoke AS Spinal Score (SASSS). Univariate logistic regression analyses were performed to identify predictors associated with new syndesmophyte development. RESULTS: Eleven (16%) patients had syndesmophytes at baseline. Nine (13.4%) patients had developed new syndesmophytes in their lumbar spines after 2 years. In the univariate logistic regression analyses, older age, longer disease duration, severe sacroiliitis, elevated C-reactive protein (CRP) levels at baseline, and one or more pre-existing syndesmophytes were associated with the occurrence of new syndesmophytes. After adjustment for baseline SASSS, increases in SASSS were statistically significantly higher in patients with elevated baseline CRP levels (p = 0.002) than in patients with normal CRP at baseline. CONCLUSIONS: Older age, longer disease duration, severe sacroiliitis, the baseline presence of syndesmophytes, and elevated levels of CRP are predictors of the development of new syndesmophytes in female AS patients.

Longitudinal study of radiographic spinal osteoarthritis in a macaque model.

Cross-sectional analyses of naturally occurring spinal osteoarthritis (OA) in primates have shown that age and body mass are significant predictors, but whether or not these relationships hold true in longitudinal evaluations remains unclear. Because spinal OA manifests similarly in humans and monkeys and macaque monkeys age >3 times the rate of humans, macaque models offer opportunities for longitudinal study that are difficult in humans. Our objective was to characterize the longitudinal development over 11 years of spinal OA in 68 Macaca mulatta (41 males, 27 females, aged 11-32 years). Average disc space narrowing (DSN) and osteophytosis (OST) scores were computed for the thoracolumbar spine (T8-L7). Our longitudinal analyses confirmed the cross-sectional results: age and body mass (p < 0.001) significantly predicted 50% and 39% of the variability in OST and DSN, respectively. Rates of change in DSN, but not OST, were associated with age at first radiograph. This study represents the first long-term longitudinal assessment of OA in primates and establishes that the relationship among the covariates in the cross-sectional and longitudinal approaches is similar.

Vertebral spinal osteophytes.

Osteoarthritis is a common complication in the elderly and is often associated with osteophyte growth on vertebral bodies. The clinical presentation of vertebral osteophytes is related to anatomical structures adjacent to the spinal column. For instance, cervical osteophytes potentially involve the pharynx and esophagus, leading to dysphagic symptoms that may be accompanied by food aspiration, vocal fold paralysis and obstructive sleep apnea. In addition to anterior cervical osteophytes, posterior and uncinate process osteophytes may form, compressing the spinal cord and vertebral artery blood supply, respectively. Cervical osteophytes have also been shown to form an accessory median atlanto-occipital joint when the relationship between the atlas, dens and basiocciput is involved. In the thorax, the esophagus is often affected by osteophytes and may result in dysphagia. Traumatic and non-traumatic thoracic aorta pseudoaneurysm formation has been attributed to sharp osteophytes lacerating the aorta, a direct complication of the relationship between the aorta anterior vertebral column. Additionally, aspiration pneumonia was reported in patients with compression of a main stem bronchus, due to mechanical compression by thoracic osteophytes. In the lumbar spinal region, the two major structures in close proximity to the spine are the inferior vena cava and abdominal aorta, both of which have been reported to be affected by osteophytes. Treatment of osteophytes is initially conservative with anti-inflammatory medications, followed by surgical removal. Increasing obesity and geriatric populations will continue to result in an array of osteoarthritic degenerative changes such as osteophyte formation.

Zygapophyseal joint adhesions after induced hypomobility.

OBJECTIVE: Adhesions (ADH) have been previously identified in many hypomobile joints, but not in the zygapophyseal (Z) joints of the spine. The objective of this study was to determine if connective tissue ADH developed in lumbar Z joints after induced intervertebral hypomobility (segmental fixation). METHODS: Using an established rat model, 3 contiguous segments (L4, L5, L6) were fixed with specially engineered, surgically implanted, vertebral fixation devices. Z joints of experimental rats (17 rats, 64 Z joints) with 4, 8, 12, or 16 weeks of induced hypomobility were compared with Z joints of age-matched control rats (23 rats, 86 Z joints). Tissue was prepared for brightfield microscopy, examined, and photomicrographed. A standardized grading system identified small, medium, and large ADH and the average numbers of each per joint were calculated. RESULTS: Connective tissue ADH were characterized and their location within Z joints described. Small and medium ADH were found in rats from all study groups. However, large ADH were found only in rats with 8, 12, or 16 weeks of experimentally induced intervertebral hypomobility. Significant differences among study groups were found for small (P < .003), medium (P < .000), and large (P < .000) ADH. The average number of medium and large ADH per joint increased with the length of experimentally induced hypomobility in rats with 8 and 16 weeks of induced hypomobility. CONCLUSIONS: We conclude that hypomobility results in time-dependent ADH development within the Z joints. Such ADH development may have relevance to spinal manipulation, which could theoretically break up Z joint intra-articular ADHs.

The role of oligodendrocytes in the molecular pathobiology and potential molecular treatment of cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is a very common and debilitating disease; however, its underlying pathocellular process remains uncertain. Attempts have been made to reproduce CSM in experimental animal models in order to deepen the knowledge on the molecular pathobiology of this disease. The up-to-date observations have established the apoptosis of oligodendrocytes (OLGs) as the principal pathocellular process of CSM. Since favorable neurological recovery cannot be obtained in afflicted patients, even after the decompression surgery, elucidation of the apoptotic cascade in OLGs may unveil possible molecular treatments which could inhibit demyelination and ameliorate the neurological deficits. Moreover, additional therapeutic benefits may include improvement of myelin self-repair capability by stimulating OLG progenitor cells to become mature and finally, myelinating OLGs. This review focuses on the factors and mechanisms of crucial importance for developing antiapoptotic treatments. Critical evaluations of the role of OLGs in molecular pathobiology of CSM as well as strategies for potential remyelination of CSM are also provided. The analyses and evaluations of the experimental findings can possibly lead to treatment of CSM as well as to development of novel biopharmacenticals.

Smaller facet effusion in association with restabilization at the time of operation in Japanese patients with lumbar degenerative spondylolisthesis.

OBJECT: The objective of this study was to assess, in patients with degenerative lumbar spondylolisthesis, which factors determine whether the involved disc levels were restabilized or remained unstable at the time of operation using multifactorial analysis. METHODS: A total of 195 consecutive patients who had received laminectomy with or without fusion at our hospital between 2003 and 2007 for progressed degenerative spondylolisthesis (slip percentage > 10% at lateral flexion position) with spinal canal stenosis participated in this study. Sagittal plane unstable motion was defined according to the criteria that translatory displacement was > 4 mm (translatory hypermobility) or rotatory displacement was > 10 degrees (rotatory hypermobility). There were 52 unstable cases (including 23 translatory and 43 rotatory hypermobility cases) and 143 stable cases. Nine parameters were investigated retrospectively as candidate factors: age, sex, body mass index, disc level, grade of disc degeneration, grade of disc spur formation, facet effusion size, length of facet spur formation, and angle between facets. The differences in the candidate factors between the unstable and stable group, together with the association between translatory or rotatory displacements and factors other than sex and disc level, were investigated. Multivariate logistic regression analysis was also used to determine independent factors for the presence of unstable motion at the time of operation. RESULTS: The unstable group had significantly greater facet effusion size (p < 0.001) than the stable group. There were no significant differences between the 2 groups in age, sex, body mass index, disc level, grade of disc degeneration, grade of disc spur formation, length of facet spur formation, or angle between facets. Multiple regression analysis for all candidate factors (except for sex and disc level) indicated that translatory displacement significantly correlated with facet effusion size positively (p < 0.001), and that rotatory displacement significantly correlated with facet effusion size positively (p < 0.001) and with age (p = -0.042) and grade of disc degeneration (p = -0.033) negatively. Logistic regression analysis for all candidate factors demonstrated that increased facet effusion size (OR 1.656, 95% CI 1.182-2.321) was the only independent factor for the presence of unstable motion at the time of operation. Facet effusion size had high negative but low positive predictive value in determining unstable motion at the time of operation. One of the reasons for the low positive predictive value was the association between facet spur formation and restabilization of the segments in the patients with greater facet effusion. CONCLUSIONS: Facet effusion size was associated with the determination of whether the affected disc was stabilized or remained unstable at the time of operation. In particular, a smaller facet effusion size strongly suggested that the affected disc had been restabilized in the patients with lumbar degenerative spondylolisthesis.

Radiologically documented adjacent-segment degeneration after cervical arthroplasty: characteristics and review of cases.

BACKGROUND: The authors retrospectively studied the incidence and characteristics of radiologically documented adjacent-segment degeneration after single-level diskectomy and subsequent cervical arthroplasty using the Bryan (Medtronic Sofamor Danek; Memphis, TN) disk prosthesis. METHODS: Seventy-two patients with single-level arthroplasty using the Bryan cervical disk prosthesis were evaluated. Radiological evidence of adjacent-disk disease included new formation or enlargement of anterior osteophyte, new or increasing ALL calcification, or narrowing of disk space documented on serial plain radiographs. We reported the characteristics of adjacent-segment degeneration and reviewed all of the cases. RESULTS: Among the 72 patients, 9 patients (12.5%) showed radiological evidence of adjacent-segment degeneration. The mean age was 43.3 years old, with a male-female ratio 1:3. The mean follow-up period was 24.2 (12.1-35.9) months. The mean period of onset was 16.3 months. Upper-segment degeneration was documented in 4 cases (3 new osteophyte, 1 enlargement of osteophyte), whereas lower-segment degeneration was noted in 5 cases (1 new osteophyte, 3 enlargement of osteophyte, 1 decreased disk height). Among the degenerated cases, 4 cases (44.4%) also showed various degrees of HO. CONCLUSIONS: The rate of adjacent-segment degeneration was higher than that observed in previous studies. Adjacent-segment degeneration documented a tendency toward HO. A longer follow-up period is necessary to investigate and document the different types of degeneration seen at levels adjacent to artificial Bryan cervical disk prostheses.

[Ocular ochronosis. A case report]. / Manifestations oculaires de l'ochronose. A propos d'un cas.

Ochronosis or alkaptonuria is a rare inherited disease. It is characterized by the deposition of dark pigments in collagen-rich tissues, which leads to clinical manifestations such as arthropathy. The ochronotic pigment can be found in the sclera, the conjunctiva, and the limbic cornea. Vision is usually not affected. We report the case of 47-year-old patient who complained of lower back pain. Ophthalmologic examination showed dark pigments in the conjunctiva. The increased levels of homogentisic acid in urine confirmed the diagnosis of ochronosis.

[Clinical observation to adjacent-segment disease after anterior cervical discectomy and fusion].

OBJECTIVE: To probe the etiopathogenisis of adjacent-segment disease by analyzing the imageology data and clinical neurological function in patients with anterior cervical discectomy and fusion (ACDF) harvested by long-term follow-up. METHODS: A retrospective study was performed on 52 patients who had undergone ACDF with perfect documents from January 1990 to April 2003. Of the patients, 45 were males and 7 were females with a mean age of 48.5 years (range from 25 to 72 years). There was the fusion of 10 one-levels, 38 two-levels and 4 three-levels. The cervical anterior-posterior and lateral X-ray, CT and MRI examination were performed before the operation. Clinical neurological function was recorded by the Nurick score, and this score at 6 weeks after the operation was compared with the later follow-up. In the radiological examination, the motion of adjacent vertebrae and osteophyte formation were reviewed on X-ray and CT, and were converted to the semi-quantitative degeneration score according to the Goffin method. The correlation between Nurick score or degeneration score and the age at operation or fusion levels was compared by Spearman correlation coefficients. The cervical canal sizes of adjacent level and remote level on MRI were reviewed and compared with each other by t test. RESULTS: The follow-up period was 3 to 10 years, 6.9 years on average. There was difference in the Nurick score between the 6th week after operation (1.07 +/- 0.84) and the later follow up (1.92 +/- 1.28) by rank test (P < 0.05). There was no correlation between the Nurick score change and the age at operation (r = 0.21, P > 0.05) or fused levels(r = 0.30, P > 0.05) by Spearman correlation coefficients. There was obvious difference in degeneration score between the 6th week after operation (0.73 +/- 0.67) and the later follow up (1.58 +/- 1.06), (P < 0.01). There was no correlation between the degeneration score change and the age at operation (r = 0.35, P > 0.05) or fusion levels (r = 0.38, P > 0.05) by Spearman correlation coefficients. The cervical canal size reductions were (1.7 +/- 1.1) mm at superior adjacent level, (1.2 +/- 0.6) mm at inferior adjacent level and (0.30 +/- 0.68) mm at remote level. There was obvious difference between superior or inferior and remote level by t test (P < 0.01). The adjacent level developed prominent degeneration together with nerve function change after the fusion operation and displayed correlation between degeneration and nerve function change(r = 0.41, P < 0.05). CONCLUSION: The adjacent-segment disease after interbody fusion is produced by multiple factors. The natural progression in adjacent disc, biomechanical natural change resulting from interbody fusion, destruction to ligament structure in front of cervical vertebrae by operation, and bone graft model are important factors not to be ignored.

Degenerative cervical spondylosis: clinical syndromes, pathogenesis, and management.

Degenerative changes in the cervical spinal column are ubiquitous in the adult population, but infrequently symptomatic. The evaluation of patients with symptoms is facilitated by classifying the resulting clinical syndromes into axial neck pain, cervical radiculopathy, cervical myelopathy, or a combination of these conditions. Although most patients with axial neck pain, cervical radiculopathy, or mild cervical myelopathy respond well to initial nonsurgical treatment, those who continue to have symptoms or patients with clinically evident myelopathy are candidates for surgical intervention.

Facet joint orientation in spondylolysis and isthmic spondylolisthesis.

STUDY DESIGN: The orientation of facet joints (FJs) in a normal population and isthmic spondylolisthesis (IS) population was assessed using magnetic resonance imaging in the lumbar spine. OBJECTIVE: To document the difference in FJ orientation (FJO) between a normal population and a population with spondylolysis of L5 and IS. SUMMARY OF BACKGROUND [corrected] DATA: Spondylolysis and IS have both a familial and mechanical etiology, yet the phenotypic expression of the familial etiology is unknown except for the observation of spinal bifida occulta. Other posterior element abnormalities are unrecognized, and any FJO abnormality below the pars defect has been ignored because of presumed previous mechanical defunctioning by the development of that pars defect at an earlier age. The recognition of multilevel sagittal FJO in L4/5 degenerative spondylolisthesis (DS), raises the possibility that more proximal segment examination may reveal FJ variations in IS. METHODS: Magnetic resonance imaging scans were used to measure the orientation of the FJ at L3/4, L4/5, and L5/S1 in 30 individuals with normal scans, and 30 patients with IS. The angular measurement recorded was in relation to the coronal plane. Repeated measurements confirmed the validity of the method. RESULTS: Mean measurement of axial FJO at L3/4 and L4/5 was 51.1 and 42.5 degrees in the controls, and 45.2 and 35.0 degrees in IS. The more coronal angulation at the levels above a pars defect in IS was highly statistically significant (P = <0.001 at L3/4 and P = <0.0001 at L4/5). At L5/S1, orientations were the same (39 degrees) in each group. CONCLUSIONS: Relative coronal FJO in the lumbar spine may be the phenotypic expression of the familial etiology of IS. This may result in increased stress concentration in the pars between or below coronally oriented FJs. These more coronal FJOs in IS may also explain the common observation of retrolisthesis at L4/5 above IS when the L4/5 disc degenerates, lateral overhang of the L4/5 FJ to the L5 pedicle entry point above an IS, and the rare combination of DS at L4/5 and IS at L5/S1 when both disorders are separately common. This latter observation can be explained by the observation that DS occurs in those individual with sagittal lumbar facets, and that IS occurs in those with more coronal FJs.

Lumbar nerve root occupancy in the foramen in achondroplasia: a morphometric analysis.

UNLABELLED: Lumbar stenosis is common in patients with achondroplasia because of narrowing of the neural canal. However, it is unclear what causes stenosis, narrowing of the central canal or foramina. We performed a morphometric analysis of the lumbar nerve roots and intervertebral foramen in 17 patients (170 nerve roots and foramina) with achondroplasia (eight symptomatic, nine asymptomatic) and compared the data with that from 20 (200 nerve roots and foramina) asymptomatic patients without achondroplasia presenting with low back pain without neurologic symptoms. The measurements were made on left and right parasagittal MRI scans of the lumbar spine. The foramen area and root area were reduced at all levels from L1 to L5 between the patients with achondroplasia (Groups I and II) and the nonachondroplasia group (Group III). The percentage of nerve root occupancy in the foramen between Group I and Group II as compared with the patients without achondroplasia was similar or lower. This implied the lumbar nerve root size in patients with achondroplasia was smaller than that of the normal population and thus there is no effective nerve root compression. Symptoms of lumbar stenosis in achondroplasia may be arising from the central canal secondary to degenerative disc disease rather than a true foraminal stenosis. LEVEL OF EVIDENCE: Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Paleoepidemiology of vertebral degenerative disease in a Pre-Columbian Muisca series from Colombia.

Major manifestations of vertebral degenerative joint disease were observed on a Pre-Columbian Muisca series from the Soacha Cemetery (11th to 13th centuries) Colombia, South America. In total, 1,646 vertebrae of 83 individuals were examined. Osteophytes, vertebral body joint surface contour change ("lipping"), and vertebral body pitting were evaluated for each vertebral body. For apophyseal joints, joint surface contour change, pitting, and eburnation were recorded. Two methods of frequency calculation and five for vertebral degenerative disease diagnosis were applied and compared, allowing discussion of methodological considerations. Our study showed that 83% of individuals and 32% of vertebrae were classified as positive when diagnosed by the presence of at least one of the following manifestations: osteophytes, vertebral body joint surface contour change ("lipping"), apophyseal joint surface contour change, or eburnation (method called "Pitting excluded"). No significant differences were found between the sexes. In the youngest cohort (15-30 years), 65% of individuals and 10% of vertebrae exhibit at least one of the previously mentioned manifestations. High prevalences suggest a high level of physical activity beginning in childhood which may have accelerated the aging process in this Pre-Columbian population. Historical data are compatible with this hypothesis.