In vivo diffusion tensor imaging of chronic spinal cord compression : a rat model with special attention to the conus medullaris.

Background Few studies have focused on diffusion tensor imaging (DTI) parameters of the conus medullaris after chronic compression in the cervical spinal cord. Purpose To discuss the correlation of DTI parameters between the chronically compressed cervical spinal cord and the conus medullaris in a rat model at different time points. Material and Methods Fifty female Sprague-Dawley rats were randomized into five groups: control group (group A), sham group (group B), and test groups C, D, and E (1, 2, and 3 weeks after compression, respectively). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of the cervical spinal cord and conus medullaris were compared among different groups. Correlations of ADC and FA values of the cervical spinal cord with those of the conus medullaris were performed in all groups. Results The ADC values at the cervical spinal cord and conus medullaris in all test groups were higher than those of group A and B, while the FA values were lower. The ADC value of the cervical spinal cord was linearly correlated with that of the conus medullaris only in group D. There were no linear correlations of FA values between the cervical spinal cord and the conus medullaris in all test groups. Conclusion After compression of the cervical spinal cord, ADC values of the cervical spinal cord and conus medullaris in test group were significantly increased, while FA values were significantly decreased. The ADC value of the cervical spinal cord was linearly correlated with that of the conus medullaris at 2 weeks after compression.

Magnetic resonance diffusion tensor imaging of cervical spinal cord and lumbosacral enlargement in patients with cervical spondylotic myelopathy.

PURPOSE: To identify the correlations of diffusion tensor imaging (DTI) indices between the cervical spinal cord and lumbosacral enlargement in healthy volunteers and patients with cervical spondylotic myelopathy (CSM). MATERIALS AND METHODS: DTI was performed at the cervical spinal cord and lumbosacral enlargement in 10 CSM patients and 10 volunteers at 1.5T. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of were measured and compared between CSM patients and volunteers. DTI indices of different cervical segments in volunteers were compared. DTI indices of the cervical spinal cord were correlated with those of the lumbosacral enlargement. RESULTS: In healthy subjects, DTI indices of different cervical cord sections showed no significant difference (ADC: F = 0.62; P = 0.65; FA: F = 1.228; P = 0.312); there was no correlation between the DTI indices of the cervical spinal cord and those of the lumbosacral enlargement (ADC: r = 0.442, P = 0.201; FA: r = -0.054, P = 0.881). In the CSM patients, the ADC value significantly increased, while the FA value significantly decreased in the cervical spinal cord (ADC: P = 0.002; FA: P < 0.001) and lumbosacral enlargement (ADC: P = 0.003; FA: P < 0.001) compared with the healthy group. Both DTI indices showed no correlation between the cervical spinal cord and those of the lumbosacral enlargement in the CSM group (ADC: r = -0.052, P = 0.887; FA: r = 0.129, P = 0.722). CONCLUSION: The ADC value of the cervical spinal cord and lumbosacral enlargement in CSM patients showed significant increase compared with healthy volunteers, while the FA value significantly decreased. Both DTI indices of the cervical spinal cord had no linear correlation with those of the lumbosacral enlargement. J. Magn. Reson. Imaging 2016;43:1484-1491.

[Radiological characteristics and clinical manifestation of isolated lumbar foraminal stenosis].

OBJECTIVE: To discuss radiological characteristics and clinical manifestation of isolated lumbar foraminal stenosis. METHODS: From March 2011 to March 2014, 21 patients with isolated degenerative lumbar foraminal stenosis accepted lumbar decompression and fusion in Beijing Luhe Hospital. Intervertebral disc space was evaluated by measuring the position of joint-body line on preoperative X-ray. Bilateral foraminal area of the corresponding segment in CT (sagittal view of 2D reconstruction) and MRI (T2W1 sagittal view) were measured by Surgimap software. For patients with unilateral symptoms, foraminal area of the affected side was compared with that of the contralateral side. Foraminal area of the same segment on CT was also compared with that on MRI. Preoperatively and at the final follow-up, visual analogue score (VAS) and Oswestry Disability Index (ODI) were used to evaluate clinical outcomes. RESULTS: All patients had a follow-up over 6 months and the average follow-up was 16.8 months (7-42 months). Of the 21 patients (26 segments), 12 segments showed gross narrowing and 14 segments showed slight narrowing. After preoperative measurement on MRI, 6 patients had foraminal stenosis of grade 2, and 15 patients had foraminal stenosis of grade 3, showing no significant difference in clinical outcomes. Compared with the foraminal area of the unaffected side, the affected side showed a decrease of 16% on CT and 28% on MRI, and the difference was statistically significant (t = 3.453, P < 0.05). The foraminal area measured on CT was larger than that measured on MRI (P < 0.05). Compared with that preoperatively, VAS (back pain), VAS (leg pain) and ODI showed significant improvement at the final follow-up (P < 0.05). CONCLUSIONS: Radiological examinations as X-ray, CT, MRI and intervertebral foramen block technique play an important role in the diagnosis of foraminal stenosis. Soft oppression caused by hyperplasia and hypertrophy of transforaminal ligment or joint capsule may be important promoters of degenerative lumbar foraminal stenosis. Lumbar foraminal decompression and interbody fusion can satisfactorily improve preoperative symptoms.

The role of the serum RANKL/OPG ratio in the healing of intertrochanteric fractures in elderly patients.

Intertrochanteric fractures occur most commonly in elderly patients. Osteoblasts and osteoclasts have been reported to be regulated by the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG), during bone modeling and remodeling, respectively. Based on these observations, we hypothesized that the serum levels of RANKL, OPG and the RANKL/OPG ratio are important in the healing of intertrochanteric fractures in elderly patients. Enzyme-linked immunosorbent assays were used to measure the serum concentrations of RANKL and OPG in 36 elderly patients with intertrochanteric fractures and 30 age-matched healthy control subjects, at baseline and 4, 8 and 12 weeks following injury. The RANKL/OPG ratio in the two groups was also evaluated. Similar trends in RANKL and OPG levels were detected during the fracture healing process. The serum levels of RANKL and OPG were higher in the fracture group than in the controls, and were significantly higher at baseline and 4 weeks following injury (P<0.05). Notably, although the RANKL/OPG ratio gradually increased during healing, it was lower in the fracture group than in the control group. The RANKL/OPG ratio was significantly lower immediately after and 4 weeks after injury in the fracture group (P<0.05). Our data suggest a close correlation between higher serum levels of RANKL and OPG and the fracture healing process, indicating that RANKL and OPG are involved in fracture healing. The serum RANKL/OPG ratio also appears to be significant in the healing of intertrochanteric fractures in elderly patients.

[Mid-term therapeutic effect analysis of cementless total knee arthroplasty without patella replacement].

OBJECTIVE: To explore the flexibility and reliability of cementless total knee arthroplasty (TKA) without patella replacement through a retrospective study of the mid-term therapeutic effect of the treatment of the patients. METHODS: From June 1997 to March 2000, a consecutive series of 152 (152 knees) cementless TKA performed in Hessing-Stiftung was studied. Among them, there were 63 males and 89 females, with 70 left knees and 82 right knees. Their ages ranged from 51 years to 72 years, with an average of 59 years. There were 146 cases of osteoarthritis and 6 cases of traumatic arthritis. The course of the disease lasted for 1.0 years to 3.5 years. The EFK prostheses of German Plus company were used in all the cases. The HSS score before the operation was 41.5 +/- 12.3, and the average range of motion was 55 degrees (ranging from 30 degrees to 90 degrees). RESULTS: Five patients underwent anterior knee pain, and the pain was released after the appropriate treatment. No deep infection happened in all cases. A total of 145 patients (145 knees) were followed up for 5 years to 8 years. The HSS score was 87.5 +/- 8.2 at the end of the follow-up, showing significant difference (P < 0.05). The average range of motion was 95 degrees (ranging from 90 degrees to 110 degrees). Partial radiolucencies occurred at the tibia side in 18 knees 3 to 6 months after the operation. Among them, the width was less than 2 mm in 15 knees without symptom, and more than 2 mm in 3 knees. There were 2 of the 3 knees which were revised at the tibia side because of the aseptic loosing, while 1 patient had only mild pain in the knee during the follow-up, with no sign of loosing. CONCLUSION: The mid-term effect of cementless TKA is satisfactory. The ingrowth of femur and tibial bones is reliable. The early stage migration of the component is the main reason of loosing. Satisfying outcomes can also be achieved without patella replacement during TKA.