[Two cases of airway dysfunction related to diacetyl exposure].

Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.

[Re-recognition of methotrexate monotherapy in rheumatoid arthritis].

With the in-depth research on treatment drugs of rheumatoid arthritis (RA), a variety of disease modifying anti-rheumatic drugs (DMARDs) have been approved for the treatment of RA. By now methotrexate (MTX) is still the anchor drug for RA treatment. The 2019 European League Against Rheumatism (EULAR) and 2021 American College of Rheumatology (ACR) recommendations for RA management both point out that for newly diagnosed RA patients, MTX monotherapy should be used as the first choice, which shows the importance of MTX monotherapy in DMARDs naïve RA. This paper mainly reviews the relevant researches on MTX in the treatment of RA in recent years, especially the relevant literature on the use of MTX monotherapy in initial treatment of RA. We summarize the development history, efficacy, treatment and adverse reactions of MTX to recognize the importance of MTX in the treatment of RA and the feasibility of MTX monotherapy.

[Clinical analysis of 10 cases with extramedullary plasmacytoma of the head and neck].

Objective: To explore the clinical characteristics, treatment methods and outcomes of extramedullary plasmacytoma of the head and neck. Methods: A retrospective analysis was conducted on 10 cases with extramedullary plasmacytoma of the head and neck who were admitted to Henan Tumor Hospital from January 2005 to January 2020. Among the 10 patients, 6 were male and 4 were female. The average age at diagnosis was 56.3 years old (34-74 years old). Among them, 3 cases were located in the nasal cavity, 2 cases in the nasopharynx, 1 case in the sinuses, 2 cases in the larynx, 1 case in the oropharynx, and 1 case in the cervical lymph nodes. Treatments were administered according to tumor size and resection extent. Complete surgical excision (negative margins) was preferred, followed by adjuvant radiotherapy or radiotherapy alone. The clinical characteristics, diagnosis, treatment and prognosis of EMP were analyzed. Results: The patients' symptoms were not specific, frequently with local obstruction symptom and localized masses. All patients were confirmed pathologically as suffering from monoclonal plasmacytoma, with negative bone marrow biopsy and negative skeletal survey. Five patients received surgery, 3 received radiotherapy, and 2 received surgery with additional radiation. The follow-up time was 16-125 months, with a median of 92 months. Two patients developed into multiple myeloma. One patient who received radiotherapy after surgery relapsed after 7 years of follow-up and again received surgical treatment, with no evidence of second recurrence. The remaining patients had no recurrence or progression. Conclusion: Extramedullary plasmacytoma of the head and neck has a good prognosis. Surgical treatment can be considered for completely resectable lesions.

[Analysis of clinical diagnosis and treatment of 12 cases of intraparotid facial nerve schwannoma].

Objective: To investigate the clinical manifestation and management strategy of intraparotid facial nerve schwannoma. Methods: The clinical data of 12 patients with parotid schwannoma treated in Henan Cancer Hospital from January 2009 to January 2019 were analyzed retrospectively, including 5 males and 7 females, aged from 23 to 72 years. All the 12 patients complained of a mass in the parotid region, of whom 4 patients had local discomfort and pain, and 6 patients had varying degrees of pain during palpation. Ultrasound examination showed solid mass in parotid region in 8 cases and mixed mass in 4 cases. The treatment methods, the relationship between tumor and facial nerve, the modes of treatments and the nerve functions before and after operation were analyzed and summarized with House-Brackmann grade. Results: All 12 patients received surgical treatment: 8 patients underwent tumor resection plus partial or total superficial parotidectomy, 1 patient underwent tumor resection and total parotidectomy, and 3 patients underwent tumor resection, with 1 patient in whom tumor could not be removed completely due to tumor extention to the skull base. In 9 cases, the tumor occurred in the trunk or main branch of the facial nerve, and there was no facial nerve injury occurred after surgery; in 1 case, the tumor occurred in the terminal branch of the facial nerve, and part of the severe small branches of adhesion were cut off during the operation; in 1 case, the total trunk of the facial nerve was not found and the broken end of the nerve could not be found during the operation, so the nerve transplantation was not performed. In 1 case, nerve grafting was performed after nerve transection because it was impossible to separate the trunk of the facial nerve from the tumor during the operation. Preoperatively, House-Brackmann grade (H-B)Ⅰfacial nerve function was shown in 10 patients, H-BⅡ in 1 patient and H-B Ⅴin 1 patient. Postoperatively, the facial nerve function recovered to H-B Ⅰfor 7 patients, H-B Ⅱfor 2 patients, H-B Ⅲ for 1 patient, grade Ⅳ for 1 patient with nerve transplantation, and H-B Ⅴfor 1 patient with a revised surgery due to tumor recurrence. Conclusions: The intraparotid facial nerve schwannoma is rare, and it is easy to be misdiagnosed before operation. Surgery is a main treatment for intraparotid facial nerve schwannoma. Attention should be paid to the protection of facial nerve during operation.

[Clinical characteristics of psoriatic arthritis with positive rheumatoid factor or anti-cyclic citrullinated peptide antibody].

OBJECTIVE: To analyze the clinical and laboratory features of psoriatic arthritis (PsA) patients with positive rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibody. METHODS: In the study, 77 PsA patients who were hospitalized in the Department of Rheumatology and Immunology of Peking University Third Hospital from January 2007 to June 2019 were enrolled. All the patients met Classification Criteria for Psoriatic Arthritis or Moll or Wright Criteria. Rheumatoid factor (RF) and anti-cyclic-citrullinated peptide (CCP) antibody were tested in these patients. According to whether anti-CCP antibody or RF was detected in serum, all the patients were divided into anti-CCP antibody or RF positive group (15 cases), anti-CCP antibody or RF negative group (62 cases). According to the detection of anti-CCP antibody in serum, all the patients were divided into anti-CCP antibody positive group (7 cases) and anti-CCP antibody negative group (70 cases). Clinical and laboratory data were collected. The differences of clinical and laboratory indicators between the RF or anti-CCP antibody positive and negative PsA patients were compared. Clinical and laboratory indicators between the anti-CCP antibody positive and negative patients were also compared. RESULTS: Among the 77 patients, 15 were RF or anti-CCP antibody positive, of whom 8 were only RF positive and 2 were only anti-CCP antibody positive, and both of RF and anti-CCP antibody were positive in 5 cases. The RF or anti-CCP antibody positive PsA patients were older than those in the negative group [(58.2±14.8) years vs. (46.69±12.27) years, P=0.002]. And metacarpophalangeal joints, elbow joints and shoulder joints were more likely to be involved in RF or anti-CCP antibody positive PsA patients. PsA patients in the anti-CCP antibody positive group were older than those in the negative group [(62.43±14.34) years vs. (47.59±12.75) years old, P=0.005]. The positive rate of RF and serum level of fibrinogen in the anti-CCP antibody positive group were higher than those in the negative group. The PsA patients in the anti-CCP antibody positive group were all polyarthritis, while 68.6% patients in the negative group were polyarthritis, but there was no statistical difference between the two groups. There was no statistical difference in sausage fingers/toes, changes in nails and enthesitis, and bone erosion on radiographs between the RF or anti-CCP antibody positive and negative PsA patients. There was also no statistical difference in sausage fingers/toes, bone erosion on radiographs, and changes in nails and enthesitis between the anti-CCP antibody positive and negative patients. CONCLUSION: RF and anti-CCP antibodies can be detected in the serum of some PsA patients. RF or anti-CCP antibody positive PsA patients were older than those in negative PsA patients. Metacarpophalangeal joints, elbow joints and shoulder joints were more likely to be involved in RF or anti-CCP antibody positive PsA patients. Anti-CCP antibody positive PsA patients were older and had higher levels of RF positive rate and fibrinogen level.

Microstructure Evolution and Nanotribological Properties of Different Heat-Treated AISI 420 Stainless Steels after Proton Irradiation.

In this paper, low-energy proton irradiation experiments with different cumulative fluences were performed on samples of AISI 420 stainless steel that were either annealed or tempered at 600 or 700 °C. The effects of the cumulative proton irradiation fluence on the evolution of the microstructure of AISI 420 were studied by transmission electron microscopy (TEM). Scratch tests were performed using a Tribo Indenter nanomechanical tester, in order to investigate the effects of the cumulative fluence on the tribological properties of the AISI 420 stainless steel. The results indicate that the dislocation density of the microstructure near the surface of the AISI 420 stainless steel increases with higher cumulative proton irradiation fluences. Under the same load, the nanoscale friction coefficient and wear rate both decreased with increasing cumulative proton irradiation fluence. This indicates that the surface hardening effect induced by proton irradiation can diminish the nanoscale friction coefficient and wear rate.

Differential responsiveness to 17ß-estradiol of mesenchymal stem cells from postmenopausal women between osteoporosis and osteoarthritis.

UNLABELLED: Differential osteogenic potential and responsiveness to 17ß-estradiol (E2) of mesenchymal stem cells (MSCs) were found between postmenopausal women with osteoporosis (OP) and osteoarthritis (OA). These results suggest differential biological mechanisms of estrogen deficiency in regulation of bone remodeling between OP and OA. INTRODUCTION: OP and OA are two common disorders in postmenopausal women. The inverse relationship has been suggested between OP and OA, but their mechanisms that relate to estrogen deficiency are not fully understood. The aim of this study was to compare the differential responsiveness to E2 of MSCs from osteoporotic versus osteoarthritic donors. METHODS: Twenty postmenopausal patients, ten with osteoporotic hip fractures and ten with hip osteoarthritis, were included into this study. MSCs were derived from cancellous bones of femoral heads from OA and OP donors and cultured in osteogenic and adipogenic medium with or without E2 added. The alkaline phosphatase (ALP) activity, calcium content, calcified nodules, lipid droplets, messenger RNA (mRNA) expression of ALP, osteocalcin (OC), collagen 1α (COL1α), peroxisome proliferators-activated receptor γ2 (PPARγ2) and lipoprotein lipase (LPL) were measured and compared between two groups with OP and OA. RESULTS: In osteogenic medium, ALP activity, calcium content and mRNA expression of OC and COL1α in MSCs from OA were significantly higher than those from OP group. In adipogenic condition, there was no significant difference in lipid droplets formation and mRNA expression of PPARγ2 and LPL between OP and OA groups. With E2 added in osteogenic medium, ALP activity, calcium content and OC mRNA were significantly higher in OP group than in OA group, whereas E2 had no significant effect on lipid droplet formation and mRNA expression of PPARγ2 and LPL. CONCLUSION: Differential osteogenic potential and responsiveness to E2 of MSCs were found between postmenopausal women with OP and OA. These results may provide information for clinical application of MSCs in the differential setting of estrogen deficiency.

Bone loss and impaired fracture healing in spinal cord injured mice.

UNLABELLED: Spinal cord injury (SCI) results in impaired fracture healing in mice while leading to significant bone loss. Poor fracture healing following SCI is consistent with significant bone loss. INTRODUCTION: SCI leads to significant bone loss in sublesional limbs, but there is few data concerning the relationship between fracture healing and bone loss following SCI. This study was undertaken to investigate the effect of SCI on fracture healing using a mouse femur fracture model. METHODS: One hundred twenty male C57BL/6J mice were randomly divided into SCI and control groups (n=60, respectively). A femoral shaft fracture was generated and fixed with intramedullary pins 3 weeks after SCI. Fracture healing was evaluated by micro-computed tomography (micro-CT) for callus formation and mineralization and neovascularization, and bone mineral density (BMD) was measured by DXA at 1, 2, and 4 weeks after fracture. Serum vascular endothelial growth factor (VEGF), osteocalcin, and alkaline phosphatase (ALP) were assessed using ELISA at each time point. Biomechanical testing was performed at 2 and 4 weeks. RESULTS: BMD in SCI mice was significantly lower compared to control mice at each time point, with callus volume and all vessel parameters reduced as measured by micro-CT. Ultimate stress of the femora was significantly lower in SCI mice than in control mice at 2 and 4 weeks after fracture, whereas Young's modulus between the SCI and control mice turned to be significantly different at 4 weeks. Serum VEGF was lower in SCI mice than in the control group at 2 and 4 weeks, whereas serum osteocalcin and ALP were lower in SCI mice than in control ones at each time point. CONCLUSION: Significant bone loss and fracture healing impairment was noted in SCI mice. Decreased angiogenesis is consistent with the changes of microarchitecture and biomechanical properties during fracture healing.

Aspergillus spondylodiscitis in solid organ transplant recipients.

BACKGROUND: Transplantation practices have had a significant effect on the epidemiology of invasive Aspergillosis. Aspergillus spondylodiscitis is rare in transplant recipients. The optimal treatment has yet to be defined because of the rarity of such cases. This article reviews the available literature on Aspergillus spondylodiscitis in solid organ transplant recipients and provides recommendations on its management. METHODS: We identified 15 cases of Aspergillus spondylodiscitis in transplant recipients. Most patients were heart transplant recipients. Back pain was the mode of presentation in all patients. Most cases were afebrile. The dominant location was the lumbar spine. RESULTS: Aspergillus fumigatus was responsible for 84.62% of cases and A flavus for 15.38%. The overall recovery rate was 66.67%. Delay in diagnosis remained a major impediment to the successful treatment of spinal aspergillosis. Treatment included antifungal therapy alone or combined with surgery. Initial therapy with voriconazole could lead to better curative effects. CONCLUSION: Combined medical and operative interventions are recommended for treatment.

Micro-CT and mechanical evaluation of subchondral trabecular bone structure between postmenopausal women with osteoarthritis and osteoporosis.

SUMMARY: An inverse relationship between osteoarthritis and osteoporosis has been debated over years. The microstructure of the femoral heads from postmenopausal osteoarthritic and osteoporotic women was evaluated with micro-CT. Significant differences were observed in microstructural parameters between them. Different microstructure might relate to the opposite bone defects in osteoarthritis and osteoporosis. INTRODUCTION: This study was undertaken to verify the inverse relationship between osteoarthritis (OA) and osteoporosis (OP) by comparing the structural and mechanical indices. METHODS: Femoral head specimens were obtained from 17 postmenopausal women (OA, n = 8; OP, n = 9) during hip surgery. The microstructural parameters were measured with micro-CT. Mechanical test was performed after bone cube scanning. RESULTS: Significant difference in bone volume fraction (BV/TV) and trabecular thickness was noted between OA and OP groups. Structure model index decreased in OA, and increased in OP. The higher apparent density (AD) and lower material density (MD) were also shown in OA. Different from OP, positive correlation were noted between connectivity density and mechanical indices in OA. In OA group, BV/TV was associated with Young's modulus and AD, while trabecular number was the only parameter that correlated with MD. However, in OP group, only BV/TV correlated with yield strength, AD, and MD. CONCLUSIONS: We observed the difference in microstructure between postmenopausal women with OA and OP, which might relate to the opposite bone defects in OA and OP. BV/TV might play an important role in mechanical properties of the subchondral bone in either OA or OP.

Changes of substance P-immunoreactive nerve fiber innervation density in the sublesional bones in young growing rats at an early stage after spinal cord injury.

UNLABELLED: Spinal cord injury (SCI) causes osteoporosis (OP), and the neuropeptide substance P (SP) may play important roles in the pathogenesis of OP after SCI. Our study confirmed SCI-induced sublesional bone loss in young rats at an early stage is associated with a significant increase of SP-immunoreactive nerve fiber innervation density. INTRODUCTION: Spinal cord injury (SCI) causes osteoporosis (OP), and neuropeptides may play important roles in the pathogenesis of OP after SCI. However, few data exist concerning the relationship between neural factors and OP following SCI. METHODS: One hundred and eight SCI and hindlimb cast immobilization (HCI) rats were studied for skeletal innervation of substance P (SP) and neurofilament 200 (NF200) with immunocytochemistry. Bone and serum SP levels were also assessed using enzyme immunoassay. RESULTS: Developing bone loss was successfully induced by SCI at 3 wks and by HCI at 6 wks. We observed a significant increase of SP-immunoreactive (IR) nerve fibers and decrease of NF200-IR nerve fibers in the tibiae of SCI rats compared with HCI and control (CON) rats at all time points. SP in the proximal tibiae in SCI rats was significantly higher than that in HCI and CON rats at all time points, but no difference was found in the serum. CONCLUSION: SCI-induced sublesional bone loss in young rats at an early stage is associated with a significant increase of nerve fiber innervation density of SP-IR and decrease of NF200-IR. We speculated that neural factors may play an important role in pathogenesis of OP after SCI.

The interobserver and intraobserver reliability of the cooney classification of distal radius fractures between experienced orthopaedic surgeons.

Various classification systems have been proposed for fractures of the distal radius, but the reliability of these classifications are seldom addressed. The objective of this study was to determine the interobserver and intraobserver reliability of the Cooney classification. Five orthopaedic surgeons with more than 10 years' experience in orthopaedic trauma assessed 43 sets of radiographic files according to the Cooney classification separately. Kappa statistics were used to analyse the interobserver and intraobserver reliability. There was moderate and substantial interobserver and intraobserver reliability of the Cooney classification without subtype, but only slight reliability when the subgroups were considered. These results question the value of this classification system for treatment decision making.

Changes in bone mass, bone structure, bone biomechanical properties, and bone metabolism after spinal cord injury: a 6-month longitudinal study in growing rats.

Spinal cord injury (SCI) results in a great decline in bone mineral density (BMD) and deterioration of bone microarchitecture. The objective of this study was to investigate the time course of the changes in BMD, microarchitecture, biomechanical properties, and bone turnover in male growing rats following SCI. Sixty male growing Sprague-Dawley rats, 6 weeks of age, were randomly divided into SCI (lower thoracic cord transection) and sham-operated groups, and bone tissues and blood samples were examined at 3 weeks, 6 weeks, and 6 months after surgery. SCI rats had low bone weight (wet, dry, and ash weight) and BMD of the femora, tibiae, and third lumbar vertebrae at all time points compared to sham rats, while in forelimbs, there was a decrease of dry and ash weight compared to sham rats only at 3 weeks but not BMD. Bone microarchitecture and trabecular connectivity were deteriorated in SCI rats and remained so after. Bone formation rate and serum osteocalcin level in SCI rats were significantly increased 3 weeks after SCI surgery. However, eroded surface/bone surface and serum N-terminal telopeptide of type I collagen level remained elevated from 3 weeks to 6 months. In addition, SCI rats showed poor biomechanical properties in the proximal tibiae and femora but not in the humeri. In conclusion, SCI causes profound BMD loss, disturbances in bone microarchitecture, decreased mechanical strength in the lower extremity and lumbar spine, and high bone turnover. These findings will allow better understanding of osteoporosis following SCI.

Differences of bone mass and bone structure in osteopenic rat models caused by spinal cord injury and ovariectomy.

UNLABELLED: Both spinal cord injury and ovariectomy can result in ostepenia in rats. SCI induces more deterioration of cortical geometric structure and trabecular microstructure in the proximal tibial metaphysis than OVX. The proximal tibial metaphysis microstructure significantly correlates with its biomechanical properties. INTRODUCTION: The purpose of the present study was to compare the effects of spinal cord injury (SCI) and ovariectomy (OVX) on bone gain in young female rats. METHODS: Thirty young female Sprague-Dawley rats were randomized into three groups: age-matched intact control (CON), OVX and SCI. The tibiae were assessed for DXA and micro-CT analysis, biomechanical testing, the upper tibial epiphyseal plate height, and blood samples for biochemical analysis. RESULTS: SCI rats showed lower aBMD in the proximal tibiae as compared with OVX rats. Cortical geometric structural parameters of the tibial midshaft in SCI rats were significantly lower than OVX rats. SCI or OVX induced significant changes in all trabecular microstructural parameters in the proximal tibial metaphysis. The trabecular separation (Tb.Sp) and structure mode index (SMI) in SCI rats were significantly higher than in OVX rats. BV/TV explained 84% of the variation of ultimate load of the proximal tibial metaphysis. There was no difference of the upper tibial epiphyseal plate height between SCI and OVX rats. Serum NTX level in SCI rats was significantly higher than in OVX rats. CONCLUSIONS: SCI induces more deterioration of cortical bone geometric structure and trabecular microstructure in the proximal tibial metaphysis than OVX.

Effects of spinal cord injury on osteoblastogenesis, osteoclastogenesis and gene expression profiling in osteoblasts in young rats.

INTRODUCTION: Spinal cord injury (SCI) causes a significant amount of bone loss in the sublesional area in animals and humans, and this type of bone loss is different from other forms of osteoporosis such as disuse osteoporosis and postmenopausal osteoporosis. However, no data is available on the cellular and molecular changes of osteoblastogenesis and osteoclastogenesis during SCI-induced bone loss. METHODS: SCI and SHAM rats were used in this study to investigate osteoblastogenesis and osteoclastogenesis in bone-marrow culture. We also measured bone mass and bone histomorphometry, as well as the expression of alkaline phosphatase (ALP), core binding factor alpha1 (Cbfa-1), osterix, receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) in osteoblast-like cells in bone-marrow culture obtained from SCI and SHAM rats. RESULTS: Bone mineral density (BMD) measurement showed serious bone loss in the tibial ephiphyses and metaphyses of SCI rats compared with SHAM rats. In addition, bone histomorphometry analysis of the tibial metaphyses of SCI rats demonstrated that bone microarchitecture in SCI rats deteriorated further than in SHAM rats, and increased eroded surfaces and bone formation rates were observed in SCI rats. The number of osteoclasts that developed from bone marrow of SCI rats at equal density was significantly increased compared with SHAM rats, and the area of the resorption pits formed in the bone marrow culture from SCI rats was significantly greater than SHAM rats, whereas the number of CFU-F and CFU-OB was similar in both groups. RANKL mRNA and protein levels in osteoblast-like cells in culture obtained from SCI rats were significantly higher than those from the SHAM rats, whereas OPG levels decreased slightly. The ratios of RANKL to OPG expression in SCI rats were significantly higher than those in SHAM rats. However, osteogenic gene profiling of Cbfa-1, ALP and osterix in SCI rats remained similar with SHAM rats. CONCLUSION: These changes favor increased osteoclast activity over osteoblast activity, and may explain, in part, the imbalance in bone formation and resorption following SCI.

Spinal cord injury causes more damage to bone mass, bone structure, biomechanical properties and bone metabolism than sciatic neurectomy in young rats.

INTRODUCTION: Although both spinal cord injury (SCI) and sciatic neurectomy (NX) can cause osteopaenia in young rats, the effects of these two injuries on cortical and cancellous bone may differ. The objective of this study was to compare the effects of SCI and NX on bone weight, bone material property, bone mass, bone geometry, trabecular microarchitecture, mechanical strength and bone turnover in young rats. MATERIALS AND METHODS: Thirty six-week-old male Sprague-Dawley rats were randomised into three groups (10 per group): SCI, bilateral sciatic NX and untreated control (CON). All rats were killed on day 21. Bone mineral density (BMD) was studied using dual-energy X-ray absorptiometry (DXA). At death, the right proximal tibial metaphysis and the fourth lumbar vertebra were examined for bone structural geometric analysis by micro-computed tomography (CT) and then processed for histomorphometry to assess bone cell activity. Serum N-terminal telopeptide of type I collagen (NTX) and osteocalcin (OC) levels were analysed by enzyme-linked immunosorbent assay (ELISA). Biomechanical strength properties of the femur and humerus were measured by three-point bending, and the third lumbar vertebra and the proximal end of tibia were tested by compression. RESULTS: BMD in the sublesional areas of SCI rats was significantly lower than that of NX rats (proximal tibia, 0.176+/-0.018 g/cm(2) vs. 0.224+/-0.015 g/cm(2), P<0.001). Bone volume (BV/TV), trabecular number (Tb.N) and thickness (Tb.Th) in the tibial second spongiosa of SCI rats were significantly less than those in NX rats (BV/TV: 7.15+/-1.18% vs. 12.32+/-1.83%, P<0.001; Tb.N: 1.23+/-0.22 vs. 2.38+/-0.45, P<0.001; Tb.Th: 33.73+/-5.15 microm vs. 42.80+/-7.44 microm, P<0.01) and trabecular separation (Tb.Sp: 1,053.37+/-164.24 microm vs. 748.32+/-129.36 microm, P<0.01) was significantly greater than in NX rats. Furthermore, poorer trabecular connectivity was found in SCI rats than in NX rats (number of nodes, N.Nd/TV: 1.04+/-0.09 vs. 3.29+/-0.53; number of terminus, N.Tm/TV: 28.53+/-3.17 vs. 21.64+/-2.31, P<0.01). The bone formation rate of the tibial second spongiosa in SCI rats was significantly higher than in NX rats (2.06+/-0.13 vs. 1.53+/-0.09, P<0.001) and, also, the eroded surface in SCI rats was significantly higher than in NX rats (13.42+/-1.24 vs. 10.36+/-1.07, P<0.001). In addition, biomechanical tests showed that SCI rats had poorer biomechanical properties of the femur, proximal tibia and fourth lumbar vertebra than in NX rats. There were significantly higher levels of OC in SCI rats compared with NX rats (30.19+/-1.17 vs. 21.15+/-1.76, P<0.001). Also, serum NTX levels were significantly higher than in NX rats (51.60+/-2.61 vs. 33.85+/-1.93, P<0.001). CONCLUSION: SCI caused more damage to bone mass, bone structure, biomechanical properties and bone metabolism than NX in young rats. This suggests that different mechanisms may underlie osteopaenia following SCI and NX.

Orientation and tropism of lumbar facet joints in degenerative spondylolisthesis.

The orientation and tropism of the lumbar facet joints at L4-5 level was assessed by magnetic resonance imaging (MRI) in 53 patients with degenerative L4-5 spondylolisthesis and 53 age- and sex-matched normal control subjects. The degree of disc degeneration at the L4-5 level and of vertebral slip on lateral radiographs was also evaluated. Patients with degenerative spondylolisthesis had more sagittally orientated facet joints (P < 0.01) and more significant facet joint tropism (P < 0.05) than normal control subjects. For patients with degenerative spondylolisthesis, the facet joint tropism was significantly correlated with the degree of disc degeneration (P < 0.05). The results suggest that morphological abnormalities of the lumbar facet joints are a predisposing factor in the development of degenerative spondylolisthesis.

Direct repair of defect in lumbar spondylolysis and mild isthmic spondylolisthesis by bone grafting, with or without facet joint fusion.

Forty-six patients with lumbar spondylolysis and mild isthmic spondylolisthesis were managed with direct repair of the defect with or without facet joint fusion in the affected segment. There were 24 males and 22 females, ranging in age from 15 to 56 years (average, 38.2 years). These patients had experienced clinical symptoms due to spondylolysis for between 4 months and 20 years (average, 5.3 years). Of 46 patients, 28 had no spondylolisthesis, 11 had Meyerding grade I vertebral slippage and 7 had grade II. Direct repair of 98 defects was performed on these patients. Twenty-six patients, in whom the disc adjacent to the defect was determined as degenerative by magnetic resonance imaging (MRI), simultaneously underwent facet joint fusion; 17 in one segment and 9 in two segments. The average period of follow-up was 50 months (24-92 months). Ninety-four defects achieved bony healing. As a result, 28 patients were graded as having an excellent outcome, 15 good, and 3 fair. Bone grafting in the defects achieves union between the loose lamina and the anterior element of lumbar vertebrae, and reconstructs the anatomic structure and physiologic functions of the lumbar vertebrae. There was no significant difference in outcome between the spondylolytic/spondylolisthetic patients with non-degenerative disc, who were treated with direct repair of defect only, and those with degenerative disc, who additionally underwent a fusion procedure (P > 0.05). The present series demonstrates a satisfactory result and a high rate of bony healing of the pars defect by this operative procedure in patients with lumbar spondylolysis and mild isthmic spondylolisthesis. Preoperative assessment of the disc degeneration with MRI is of great assistance in making the protocol choice of whether to opt for fusion.

Acute central cervical cord injury: the effect of age upon prognosis.

In this clinical study, a total of 89 consecutive patients with acute cervical cord injury was analysed retrospectively. There were 29 patients aged 60 years and over, accounting for 32.6% of all the cases. All the patients were followed up from 1 to 15 years, with an average of 6 years and 4 months. Among the patients of 60 years and over, 27 (93.1%) had both upper and lower extremities involved, compared with 40 (66.7%) of those under 60 years (P<0.05). Also among the older group, 24 had radiographic findings of severe cervical spinal degeneration, a higher incidence than in the patients under 60 years (P<0.05). There were two deaths in patients of 60 years and older. The average American Spinal Injury Association (ASIA) scores in both the younger and older groups at final follow-up were significantly larger (P<0.01) than on admission, but the age of the patients was negatively correlated with the ASIA scores both on admission (P<0.05) and at final follow-up (P<0.01). The ASIA score was significantly lower (P<0.01) in patients aged 60 years and over than in those younger than 60 years both on admission and at final follow-up. Patients aged 60 years and over with acute central cervical cord injury have a poorer prognosis although they may experience significant neurological improvement.

Remodeling of the spinal canal after thoracolumbar burst fractures.

Thirty-one patients with thoracolumbar burst fractures, seven untreated, 16 treated nonoperatively, and eight treated operatively, were analyzed retrospectively and followed up for 3 to 7 years. The initial and final degrees of neurologic deficit and the stenotic ratio of the spinal canal were recorded. Stenotic ratio significantly decreased from the first examination (range, 12.3%-74.5%; average, 26.2%) to the final followup (range, 5.4%-46.5%; average, 19.2%), but there were no differences of the percentage of remodeling between patients who were untreated and those treated nonoperatively and operatively. The recovery rate was highly significantly related to the stenotic ratio at first examination. Nonoperative management may be considered for treatment of patients who are neurologically intact or only slightly impaired with thoracolumbar burst fractures.