Low-adhesion and low-swelling hydrogel based on alginate and carbonated water to prevent temporary dilation of wound sites.

Hydrogel-based wound dressings have been developed for rapid wound healing; however, their adhesive properties have not been adequately investigated. Excessive adhesion to the skin causes wound expansion and pain when hydrogels absorb exudates and swell at wound sites. Herein, we developed a low-adhesion and low-swelling hydrogel dressing using alginate, which is non-adhesive to cells and skin tissue, CaCO3, and carbonated water. The alginate/CaCO3 solution rapidly formed a hydrogel upon the addition of carbonated water, and the CO2 in the hydrogel diffused into the atmosphere, preventing acidification and obtaining a pH value suitable for wound healing. Remarkably, the skin adhesion and swelling of the hydrogel were 11.9- to 16.5-fold and 1.9-fold lower, respectively, than those of clinical low-adhesion hydrogel dressings. In vivo wound-healing tests in mice demonstrated its therapeutic efficacy, and the prepared hydrogel prevented temporary wound dilation during early healing. These results illustrate the importance of controlling skin adhesion and swelling in wound dressings and demonstrate the potential clinical applications of this wound-friendly hydrogel dressing.

Ultrasonographic evaluation of medial radial displacement of the medial meniscus in knee osteoarthritis.

OBJECTIVE: To evaluate medial radial displacement (MRD) of the medial meniscus in osteoarthritic (OA) and normal knees, with and without weight bearing, using ultrasonography (US), and to prospectively evaluate the time course of changes in MRD in OA knees. METHODS: The study subjects were 78 patients with OA of the knee (69% female; mean age 66.4 years) and 20 healthy, asymptomatic subjects (70% female; mean age 64.5 years) who served as a control group. The OA stage was determined according to the Kellgren/Lawrence (K/L) radiographic grading system. US measurement of MRD was performed with subjects in the supine and standing positions. With the exception of subjects who dropped out, 58 OA knees (followup rate 74%) were evaluated at baseline and ∼1 year later. RESULTS: The medial meniscus was significantly displaced radially by weight bearing in control knees (P<0.001) and in knees with K/L grades 1-3 OA (P<0.01 for each comparison). MRD in either the supine or the standing position was not significantly different between the control knees and the K/L grade 1 knees, but significant differences were noted between the control knees and K/L grade 2 or more severe OA knees (P<0.01 for each comparison). MRD of the medial meniscus had increased significantly on followup in all knees (P<0.05 for each comparison) excluding K/L grade 4 knees in the standing position. CONCLUSION: MRD of the medial meniscus increased with weight bearing and during followup. These findings suggest a close association between extraarticular displacement of the medial meniscus and progression of OA.

Intramuscular myxoma of the buttock mimicking low-grade fibromyxoid sarcoma: diagnostic usefulness of MUC4 expression.

Intramuscular myxoma (IM) is a benign intramuscular neoplasm composed of fibroblasts and abundant myxoid stroma. Some malignant soft tissue tumors can undergo myxomatous degeneration, which makes it difficult to distinguish them from IM. We describe a case of IM of the buttock region mimicking low-grade fibromyxoid sarcoma. The tumor appeared as a well-defined ovoid mass with a cystic lesion on MRI images, and mild uptake on PET images was seen. This was originally misdiagnosed as low-grade fibromyxoid sarcoma (LGFMS) after core-needle biopsy. The mass was excised en bloc and sent for histology. The surgical specimen showed the features of LGFMS with the same characteristics as those mentioned in the previous biopsy report. After surgery, MUC4 expression, a highly sensitive and specific immunohistochemical marker for LGFMS, and FUS gene rearrangement by FISH was not detected upon re-examination; therefore, a conclusive diagnosis of IM was made. The patient had no local recurrence at the 3-year follow-up. Our case suggests that IM with mild FDG uptake is frequently confused with other low-grade malignant myxoid tumors. In addition, absence of MUC4 expression is the definitive key to distinguish IM from LGFMS.

Functional haplotypes of PADI4, encoding citrullinating enzyme peptidylarginine deiminase 4, are associated with rheumatoid arthritis.

Individuals with rheumatoid arthritis frequently have autoantibodies to citrullinated peptides, suggesting the involvement of the peptidylarginine deiminases citrullinating enzymes (encoded by PADI genes) in rheumatoid arthritis. Previous linkage studies have shown that a susceptibility locus for rheumatoid arthritis includes four PADI genes but did not establish which PADI gene confers susceptibility to rheumatoid arthritis. We used a case-control linkage disequilibrium study to show that PADI type 4 is a susceptibility locus for rheumatoid arthritis (P = 0.000008). PADI4 was expressed in hematological and rheumatoid arthritis synovial tissues. We also identified a haplotype of PADI4 associated with susceptibility to rheumatoid arthritis that affected stability of transcripts and was associated with levels of antibody to citrullinated peptide in sera from individuals with rheumatoid arthritis. Our results imply that the PADI4 haplotype associated with susceptibility to rheumatoid arthritis increases production of citrullinated peptides acting as autoantigens, resulting in heightened risk of developing the disease.

Clinical features and surgical outcomes of lumbar spinal stenosis in patients aged 80 years or older: a multi-center retrospective study.

INTRODUCTION: With increased aging of the population, spine surgeons have more opportunity to treat elderly patients for lumbar spinal stenosis (LSS). The purpose of this study was to clarify the clinical features and surgical outcomes for LSS in the elderly aged 80 years or older. MATERIALS AND METHODS: We retrospectively reviewed 702 consecutive patients with LSS who underwent decompression surgery without fusion between 2006 and 2010. Patients with other conditions that could affect functional status were excluded from this study. Of the remaining 304 patients, 241 with LSS whose condition could be evaluated 6 months at least after surgery were analyzed. The mean follow-up period was 14.4 months (range 6-60 months). There were 144 males and 97 females aged 45-93 years old (average: 72.2 years old). Patients were divided into two age groups: 80 years or older (Group A, 46 patients) and under 80 years of age (Group B, 195 patients). We evaluated differences in the clinical features and surgical outcomes between the two groups. RESULTS: There were no significant differences in surgical levels, the number of operation levels, operation times, or the amount of intraoperative bleeding between Groups A and B. The percentages of patients with comorbidities were 73.9 % in Group A and 60.0 % in Group B, which were not significantly different. There were no significant differences in Japanese Orthopaedic Association scores preoperatively, 6 months postoperatively, and at the final follow-up between the two groups. Furthermore, recovery ratios 6 months postoperatively and at final follow-up were similar between the two groups. The percentages of patients with postoperative complications were 19.6 % in Group A and 13.3 % in Group B, which were not significantly different. CONCLUSIONS: This multi-center retrospective study demonstrated that the benefits and risks of decompression surgery for LSS were similar between patients aged over 80 years and those under 80 years. Therefore, decompression surgery is a reasonable treatment even for elderly patients aged over 80 years.

Multifocal localized pigmented villonodular synovitis arising separately from intra- and extra-articular knee joint: case report and literature review.

We present a case of intra- and extra-articular localized pigmented villonodular synovitis (PVNS) of the right knee joint separately. A 14-year-old girl presented with a painful mass over the medial aspect of the right knee. MRI demonstrated nodular masses located in the anteromedial area of the knee joint and on the surface of the deep medial collateral ligament outside the joint. Arthroscopic and open synovectomy were performed for both lesions. Histopathology confirmed diagnosis of localized PVNS and pigmented villonodular bursitis, respectively. Our case highlights that localized PVNS are likely to occur in intra- and extra-articular regions separately.

Early surgical intervention for spinal infection in patients with malignancy requiring chemotherapy: report of two cases and review of the literature.

Advances in chemotherapy for various malignancies have contributed to the increased life expectancy of patients. If such a patient has a concurrent infection, his/her oncologist would hesitate to perform prompt chemotherapy owing to the risk of inducing sepsis. Therefore, the treatment of infection would have priority over initiating chemotherapy for the malignancy. We present a 69-year-old female with malignant lymphoma requiring prompt chemotherapy who also demonstrated spinal infection with Mycobacterium tuberculosis and a 66-year-old male with esophageal cancer who also demonstrated spinal infection with Staphylococcus aureus. Anterior debridement and interbody fusion were performed for both patients. One patient died of malignant lymphoma 4 years after surgery, and the other is still alive and has remained disease-free 4 years after surgery. Saving the life of a patient with malignancy would be difficult without prompt chemotherapy. Conservative treatment for spinal infection requires prolonged antibiotic treatment, and there is no guarantee that the spinal infection would be controlled only with antibiotics. Therefore, early surgical intervention would be an alternative option under such a condition.

Physicochemical Properties of Egg-Box-Mediated Hydrogels with Transiently Decreased pH Employing Carbonated Water.

Anionic polysaccharides, including low-methoxy (LM) pectin, are extensively used in biomaterial applications owing to their safety, biocompatibility, and feasibility in constructing supramolecular assemblies by forming egg-box structures with divalent cations. Mixing an LM pectin solution with CaCO3 spontaneously forms a hydrogel. The gelation behavior can be controlled by adding an acidic compound to change the solubility of CaCO3. CO2 is used as the acidic agent and can be easily removed after gelation, thereby reducing the acidity of the final hydrogel. However, CO2 addition has been controlled under varied thermodynamical conditions; therefore, specific CO2 effects on gelation are not necessarily visualized. To evaluate the CO2 impact on the final hydrogel, which would be extended to control hydrogel properties further, we utilized carbonated water to supply CO2 into the gelation mixture without changing its thermodynamic conditions. The addition of the carbonated water accelerated gelation and significantly increased the mechanical strength, promoting cross-linking. However, the CO2 volatilized into the atmosphere, and the final hydrogel became more alkaline than that without the carbonated water, probably because a considerable amount of the carboxy group was consumed for cross-linking. Moreover, when aerogels were prepared from the hydrogels with carbonated water, they exhibited highly ordered networks of elongated porosity in scanning electron microscopy, proposing an intrinsic structural change by CO2 in the carbonated water. We also controlled the pH and strength of the final hydrogels by changing the CO2 amounts in the carbonated water added, thereby validating the significant effect of CO2 on hydrogel properties and the feasibility of using carbonated water.

Clinical features of spinal infection in individuals older than eighty years.

PURPOSE: Japan has one of the most rapidly increasing numbers of elderly individuals; therefore, future trends in spinal infections in the elderly in other countries may be predicted by studying such characteristics in Japan. The purposes of this study were to identify whether the incidence of spinal infection in individuals more than 80 years old is increasing and to define its clinical characteristics. METHODS: We retrospectively reviewed the medical records of 98 patients treated in our hospital for spinal infection between 1999 and 2008. Patients were divided into two groups: those admitted to our hospital during the initial five year period, and those admitted during the latter five year period. We evaluated changes in the percentage of individuals over the age of 80 years. To define the clinical characteristics of spinal infection, patients were also divided into another set of two groups: those over 80 years and those around the age of 80 years. RESULTS: The percentage of patients over 80 years with spinal infection was significantly increasing. There was no significant difference in the gender distribution, prevalence of immunocompromised hosts, common involved levels, or mortality rate between the two age groups. The pathogenic organism was isolated in 78.6%, and of these, the rate of methicillin-resistant Staphylococcus aureus or epidermidis was 2.46 times higher in the elderly group than in the younger group. CONCLUSIONS: The number of patients over 80 years with spinal infection is expected to rapidly increase in aging societies. This advanced age group is more susceptible to infection with drug-resistant organisms, which makes infection management more difficult.

Surgical outcomes and prognostic factors of cervical spondylotic myelopathy in diabetic patients.

BACKGROUND: There have been a few reports on the surgical outcomes of cervical myelopathy in diabetic patients; however, those studies included ossification of the posterior longitudinal ligament. This study investigated whether surgical outcome of expansive laminoplasty (ELAP) for diabetic patients with cervical spondylotic myelopathy (CSM) differs from that for non-diabetic patients and determined prognostic factors in diabetic patients. METHODS: We retrospectively reviewed 78 patients with CSM after excluding the cases with other medical conditions, which could affect surgical outcome from 222 consecutive patients who had undergone ELAP between 2000 and 2008 in our hospital. The patients were divided into two groups: diabetic patients (Group 1) and non-diabetic patients (Group 2). We evaluated differences in age, gender, pre- and postoperative Japanese Orthopaedic Association (JOA) score, recovery rate (RR), symptom duration, and postoperative complications between the two groups. In Group 1, the correlation between RR and factors indicating the severity of diabetes mellitus was assessed. RESULTS: There were 13 patients in Group 1 and 65 in Group 2. There was no significant difference in age, gender, JOA score before or after surgery, or symptom duration between the two groups. Group 1 showed poorer recovery of sensory and motor function in the lower extremities. A negative correlation was observed between RR and the preoperative hemoglobin A(1c) (HbA(1c)) level in Group 1. CONCLUSIONS: Diabetic patients experienced benefits from ELAP similar to non-diabetic patients. A negative correlation between RR and preoperative HbA(1c) level suggests that strict blood sugar control is recommended before surgery.

Effect of raloxifene on arthritis and bone mineral density in rats with collagen-induced arthritis.

We studied the effect of raloxifene (RAL) on arthritis and bone mineral density (BMD) in rats with collagen-induced arthritis (CIA). Seven-month-old female Sprague-Dawley rats were divided into five groups: rats without CIA (CNT), CIA rats that underwent ovariectomy (OVX) and were treated with RAL (CIA + OVX + RAL), CIA rats that underwent OVX and were treated with vehicle (CIA + OVX + Veh), CIA rats that had sham surgery and were treated with RAL (CIA + sham + RAL), and CIA rats that had sham surgery and were treated with vehicle (CIA + sham + Veh). RAL was orally administered at 10 mg/kg every day for 3 weeks, beginning 1 week after initial sensitization until death at 4 weeks. Every week until death, we evaluated hind paw thickness and arthritis score. BMD was measured by peripheral quantitative computed tomography at the distal metaphysis and the diaphysis of the femur; we also performed histomorphometry of the proximal tibia and histological evaluation of arthritis. RAL administration suppressed hind paw thickness and arthritis score and prevented decreases in BMD and cortical thickness. In the histomorphometric analysis, bone-resorption parameters were significantly lower in the RAL groups than in the Veh groups. RAL significantly inhibited synovial proliferation in CIA rats. RAL effects on arthritis and bone were apparent regardless of whether an animal had undergone OVX. RAL could suppress arthritis and bone loss in estrogen-replete or -depleted rats. These findings, using an animal model, indicate the potential usefulness of RAL as an effective treatment for premenopausal RA patients as well as postmenopausal ones.

Recent trends in adult-onset septic arthritis of the knee and hip: retrospective analysis of patients treated during the past 50 years.

This study was a retrospective analysis of 53 adult patients with septic arthritis (SA) of the knee or hip treated during the years from 1955 to 2005 in Tottori University Hospital in Japan. Patients with postoperative infection, infection caused by trauma, and periprosthetic infection were excluded. The 50-year period between 1955 and 2005 was divided into five periods: there were 5 patients in the first decade, 9 in the second decade, 11 in the third decade, 10 in the fourth decade, and 18 in the fifth decade. All SA occurred in the knee until the fourth decade. Five cases of septic arthritis in the hip occurred in the fifth decade. In contrast to the decrease in direct infections (post intraarticular injection), hematogenous infections were observed to increase after 1986. The rate of SA caused by Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA) had been highest during the 50 years. Infections caused by MRSA, comprising 22% of all staphylococcal infection, occurred in the fifth decade. The numbers of patients with comorbid conditions such as diabetes increased during the 50-year period. This study indicated that patients with SA have been increasing in number. Furthermore, hematogenous SA has been increasing. The increase in occurrence of SA could result from increase in opportunistic infection, occurrence of SA of the hip, and increase in MRSA infection.

Clinical features and surgical outcomes of cervical spondylotic myelopathy in patients aged 80 years or older: a multi-center retrospective study.

With the aging of the population in developed countries, spine surgeons have recently been more likely to encounter elderly patients in need of treatment. This study investigated whether decompression surgery for cervical spondylotic myelopathy (CSM) in elderly patients aged 80 years or older would likely be a reasonable treatment. We retrospectively reviewed 605 consecutive patients with cervical myelopathy who underwent decompression surgery between 2004 and 2008. Patients with other conditions that could affect functional status or compression factors other than spondylosis were excluded from this study. Of the remaining 189 patients, 161 with CSM whose condition could be evaluated 6 months after surgery were analyzed. The patients were divided into two age groups: 80 years or older (Group A, 37 patients) and younger than 80 years of age (Group B, 124 patients). We evaluated the differences in symptom duration, clinical data, involved levels, surgical outcome, comorbidities, and postoperative complications between the two groups. The symptom duration was significantly shorter in Group A. The average JOA scores preoperatively and 6 months postoperatively were significantly lower in Group A; however, there was no significant difference in the recovery ratio. There were no significant differences in the percentages of patients with comorbidities or those with postoperative complications. Elderly patients aged 80 years or older regained approximately 40% of their function postoperatively, and the incidence of postoperative complication was similar to that in younger patients. Since this age group shows a rapid deterioration after onset, prompt decompression surgery is required.

High-resolution nuclear magnetic resonance spectroscopic study of metabolites in the cerebrospinal fluid of patients with cervical myelopathy and lumbar radiculopathy.

There have been few reports describing substances related to oxidative and intermediary metabolism in the cerebrospinal fluid (CSF) in patients with spinal degenerative disorders. This study investigated whether the concentrations of metabolites in the CSF differed between patients with spinal degenerative disorders and controls, and whether the concentrations of these metabolites correlated with the severity of symptoms. CSF samples were obtained from 30 patients with cervical myelopathy (Group M), 30 patients with lumbar radiculopathy (Group R), and 10 volunteers (control). Metabolites in these CSF samples were measured by nuclear magnetic resonance spectroscopy. There were no differences in the concentrations of lactate, alanine, acetate, glutamate, pyruvate, or citrate between Groups M and R, between Group M and the control, or between Group R and the control. In Group M, neither symptom duration nor the Japanese Orthopaedic Association score correlated with the concentration of any metabolite. In Group R, the symptom duration positively correlated with the concentration of lactate, glutamate, and citrate in CSF. The duration of nerve root block showed a negative correlation with the concentrations of acetate in CSF of the patients in Group R. In patients with lumbar radiculopathy, there is a possibility of increased aerobic metabolic activity or decreased gluconeogenic activity in patients with shorter symptom duration, and increased aerobic metabolic activity in patients with severe inflammation around a nerve root.

Spinal subdural haematoma concurrent with cranial subdural haematoma: Report of two cases and review of literature.

Subdural haematomas co-existing in the cranium and spine are considered extremely rare. We report 2 cases demonstrating the condition described here with a review of literature. One of these 2 patients was the first case in which the spinal lesion was found before the cranial lesion. A 66-year-old man without trauma presented with paraparesis accompanied by severe leg pain. The patient was diagnosed as having spinal subdural haematoma extending from L1 to S1 vertebral levels with magnetic resonance images (MRI). Two days after admission, the patient developed disorientation and abnormal behavior; therefore, computed tomography (CT) of brain was performed, and chronic cranial subdural haematoma was observed. A 60-year-old man who developed headache showing gradually progressive was diagnosed as having cranial subdural haematoma on CT. Three days after admission, he became insomnolent due to severe low back pain radiating to ankle. On MRI, subdural haematoma was found extending from L3/4 to S2 vertebral levels. Only brain surgery was performed for all cases by the neurosurgeons. Paraparesis and severe leg pain, which were derived from spinal lesions, showed recovery approximately 2 weeks after onset and spinal subdural haematoma was completely resolved on MRI obtained 2 or 5 months after onset, respectively. There is a possibility that the incidence of spinal subdural haematoma concurrent with cranial subdural haematoma could be underestimated because the doctor had not obtained CT or MRI of the brain. Doctors should aware of such a condition and check patients with spinal subdural haematoma for neurological signs derived from brain lesions. Spontaneous resolution of spinal subdural haematoma was observed; therefore, surgery for this condition should be indicated only for patients with moderate or severe paraparesis or paraparesis deteriorated.

Recent trends in spinal infections: retrospective analysis of patients treated during the past 50 years.

We retrospectively reviewed the medical charts of 210 consecutive patients treated for spinal infection in Tottori University Hospital in Japan between 1956 and 2005. Until 1995, spinal infection was under control in this series; however, during the last decade, it has been on the rise. Male predominance had been gradually progressing, and 69% of the patients were male during the last decade. Patients with spinal infection were aging, and the ratio of immunocompromised hosts dramatically increased to 53%. Until 1995, the percentage of patients with tuberculous spondylitis had been declining; however, the incidence has been on the rise during the last ten years. The organism was detected in 64% of patients treated between 1996 and 2005, of which Staphylococcus aureus was detected in 49%. Moreover, methicillin-resistant S. aureus was detected in 61% of patients with S. aureus. There were no immigrants or cases with human immunodeficiency virus in this series.

Insufficiency fracture at the distal diaphysis of the radius after synovectomy combined with the Sauvé-Kapandji procedure in a patient with rheumatoid arthritis.

We report here a rare case of insufficiency fracture at the distal diaphysis of the radius in a patient with rheumatoid arthritis (RA) after synovectomy combined with the Sauvé-Kapandji procedure. A 71-year-old woman who had been diagnosed with RA had been consecutively treated with several disease-modifying antirheumatic drugs. She had undergone synovectomy of the right wrist combined with the Sauvé-Kapandji procedure, due to a tendon rupture, 2 years before the current presentation (first visit). Although she had not experienced any recent trauma, the wrist pain had increased after she had lifted up the bedding at the funeral of her friend about 1 month prior to her first visit. Radiographs of her right wrist taken at the second visit showed a fracture at the distal diaphysis of the radius at the level of the excision osteotomy of the distal ulna; however, no displacement of the distal fragment was observed. We immobilized her forearm in a long-arm cast. However, after 3 weeks of cast immobilization, a displacement of the distal fragment was observed. A manual reduction of the displacement was performed and the arm was again immobilized in a long-arm cast. However, 1 week later, a displaced distal fragment was again observed. Subsequently, she received an open reduction and internal fixation using a volar locking plate and screws with an autologous iliac crest bone graft. Bone union was completed by 8 months following the operation.

A physician-staffed ground emergency medical service does not significantly shorten door-to-balloon time in patients with STEMI: an observational study in a single emergency center in Japan.

AIM: Current guidelines recommend a door-to-balloon time (DTBT) of <90 min for reperfusion treatment of patients with ST-segment elevation myocardial infarction (STEMI). A physician-staffed ground emergency medical service (GEMS) using a rapid response car (RRC) system was implemented at our hospital in April 2015. The medical team, including a physician and nurse, is dispatched to assess the patient and expedite the start of treatment by emergency physicians and cardiologists after arrival at the hospital. The study aimed to determine whether the RRC system shortened the DTBT. METHODS: This retrospective observational study was carried out in a tertiary emergency center in Japan. Those STEMI patients with primary percutaneous intervention between January 2016 and December 2018 were evaluated. The DTBTs of patients transported by the RRC system, the emergency medical service (EMS), and transferred from other hospitals after STEMI diagnosis (TRANS group) were compared. RESULTS: A total of 121 patients were included, 33 in the RCC, 20 in the EMS, and 68 in the TRANS groups. The median DTBT was 51 min (interquartile range [IQR], 43-67) in the RRC, 61 min (IQR, 52-85) in the EMS, and 59 min (IQR, 48-72) in the TRANS groups (P = 0.13). The DTBT was not significantly shorter in the RRC than in the other groups. CONCLUSION: An RRC physician-staffed GEMS did not significantly shorten the DTBT of patients with STEMI compared with other transport systems.

Tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 in the cerebrospinal fluid of patients with cervical myelopathy and lumbar radiculopathy.

There have been few reports describing cytokines in the cerebrospinal fluid (CSF) of patients with spinal degenerative disorders. This study investigated whether interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) could be detected in CSF of patients with cervical myelopathy or lumbar radiculopathy and whether the concentrations of those cytokines correlated with the severity of disease conditions. CSF samples were obtained from 21 patients with cervical myelopathy (Group M) and 19 patients with lumbar radiculopathy (Group R), and six volunteers (control). The concentration of IL-6 was significantly higher in Groups M and R than in the control, possibly demonstrating spinal cord and nerve root damage, respectively. However, TNF-alpha was lower than the detection limit. IL-1beta was detected in only five samples from three patients in Group M and two volunteers in the control. The concentrations of IL-6 did not show any correlation with symptom duration, the scoring system by the Japanese Orthopaedic Association, or the duration of nerve root block. There is a possibility that the concentration of inflammatory cytokines in CSF can indicate certain pathological aspects of cervical myelopathy or lumbar radiculopathy.

Histological Evaluation of Lumbar Spine Changes in Rats with Collagen-induced Arthritis.

BACKGROUND: To histologically evaluate lumbar involvement in rheumatoid arthritis (RA) by investigating rats with collagen-induced arthritis (CIA) and to assess the potential effects of RA on the discovertebral joints and facet joints. METHODS: Seven-month-old female Sprague-Dawley rats were divided into groups with CIA and without CIA (control). All rats were sacrificed at 8 weeks after initial sensitization and the lumbar spine (L5/6) was harvested. Then the lumbar spine block specimens were stained with Villaneuva bone stain and sectioned in the midsagittal plane. The left facet joints were also sectioned in the midaxial plane. Specimens were studied under a microscope and infiltration of inflammatory cells was investigated. RESULTS: In the CIA group, lumbar lesions were observed in 13/18 rats (76%). Lymphocytes infiltrated into the anterior rim of the vertebral bodies only in 2 rats, while lymphocytes infiltrated the facet joints only in 4 rats. Both sites were involved in 7 rats. In addition, osteoclasts invaded the anterior rim of the vertebral bodies and formed cavities that also contained lymphocytes. Formation of pannus was seen in the facet joints in 11/18 rats. CONCLUSION: In CIA rats, infiltration of inflammatory cells into the anterior rim of the vertebral bodies alone or into the facet joints alone was demonstrated in 2 rats and 4 rats, respectively, while both sites were involved in 7 rats. Therefore, lesions at the anterior rim of the vertebral body did not arise secondary to facet joint involvement, but were caused by CIA along with synovial lesions of the facet joints.