OBJECTIVE: Bilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy. MATERIALS AND METHODS: Six patients who underwent hysterectomy and bilateral salpingo-oophorectomy were studied. At baseline, mean patient age was 49.5 years (range: 45-54 years). Third lumbar vertebral body BMD measurement using quantitative CT, marrow fat fraction (FF) using MR spectroscopy and marrow perfusion using dynamic contrast enhanced MRI were conducted immediately prior to surgery and at 3, 9, and 21 months after surgery. RESULTS: Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 +/- 7.2% in BMD (n = 6), a sharp increase of 92.2 +/- 46.3% (n = 6) in FF, a sharp decrease of 23.6 +/- 3.9% in maximum contrast enhancement (n = 5), and of 45.4 +/- 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05). CONCLUSION: Bilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.
Body Mass Index ; Bone Density ; Bone Marrow/*metabolism ; Contrast Media/diagnostic use ; Female ; Humans ; Hysterectomy ; Lipids/analysis ; Longitudinal Studies ; Lumbar Vertebrae/*radiography ; *Magnetic Resonance Imaging ; Middle Aged ; Ovariectomy ; Prospective Studies

OBJECTIVETo investigate sex hormone deficiency related osteoporosis and efficacy of different therapies.

METHODSOrchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density (BMD) characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography.

RESULTSPara-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery.

CONCLUSIONThe approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.

Animals ; Bone Density ; drug effects ; Female ; Gonadal Steroid Hormones ; deficiency ; metabolism ; Lumbar Vertebrae ; physiology ; Male ; Orchiectomy ; Ovariectomy ; Rats ; Sex Factors

Objective: To investigate changes in the median nerve, retinaculum, and carpal tunnel on ultrasound after successful endoscopic carpal tunnel release (ECTR). Materials and Methods: This prospective study involved 37 wrists in 35 patients (5 male, 30 female; mean age ± standard deviation [SD], 56.9 ± 6.7 years) with primary carpal tunnel syndrome (CTS). An in-house developed scoring system (0–3) was used to gauge the clinical improvement after ECTR. Ultrasound was performed before ECTR, and at 1, 3, and 12 months post-ECTR. Changes in the median nerve, flexor retinaculum, and carpal tunnel morphology on ultrasound after ECTR were analyzed. Ultrasound parameters for different clinical improvement groups were compared. Results: All patients improved clinically after ECTR. The average clinical improvement score ± SD at 12 months post-ECTR was 2.2 ± 0.7. The median nerve cross-sectional area proximal and distal to the tunnel decreased at all time intervals postECTR but remained swollen compared to normal values. Serial changes in the median nerve caliber and retinacular bowing after ECTR were more pronounced at the tunnel outlet than at the tunnel inlet. The flexor retinaculum had reformed in 25 (68%) of 37 wrists after 12 months. Conclusion Postoperative changes in median nerve and retinaculum parameters were most pronounced at the tunnel outlet.Even in patients with clinical improvement after ECTR, nearly all ultrasound parameters remain abnormal at one year postECTR. These ultrasound parameters should not necessarily be relied upon to diagnose persistent CTS after ECTR.

Objective: To investigate changes in the median nerve, retinaculum, and carpal tunnel on ultrasound after successful endoscopic carpal tunnel release (ECTR). Materials and Methods: This prospective study involved 37 wrists in 35 patients (5 male, 30 female; mean age ± standard deviation [SD], 56.9 ± 6.7 years) with primary carpal tunnel syndrome (CTS). An in-house developed scoring system (0–3) was used to gauge the clinical improvement after ECTR. Ultrasound was performed before ECTR, and at 1, 3, and 12 months post-ECTR. Changes in the median nerve, flexor retinaculum, and carpal tunnel morphology on ultrasound after ECTR were analyzed. Ultrasound parameters for different clinical improvement groups were compared. Results: All patients improved clinically after ECTR. The average clinical improvement score ± SD at 12 months post-ECTR was 2.2 ± 0.7. The median nerve cross-sectional area proximal and distal to the tunnel decreased at all time intervals postECTR but remained swollen compared to normal values. Serial changes in the median nerve caliber and retinacular bowing after ECTR were more pronounced at the tunnel outlet than at the tunnel inlet. The flexor retinaculum had reformed in 25 (68%) of 37 wrists after 12 months. Conclusion Postoperative changes in median nerve and retinaculum parameters were most pronounced at the tunnel outlet.Even in patients with clinical improvement after ECTR, nearly all ultrasound parameters remain abnormal at one year postECTR. These ultrasound parameters should not necessarily be relied upon to diagnose persistent CTS after ECTR.

Background The association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined.This study was to evaluate the structural,densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones.Methods Bone mineral density (BMD) at hip and femoral midshaft,bone cross-sectional area,moment of inertia of both femurs,bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly.Results The total hip BMD and t-score were found not different between two groups.However,bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft (P ＜0.05); morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia (P ＜0.01).High resolution-peripheral quantitative computed tomography showed significantly decreased trabecular density,bone volume ratio,trabecular number but increased trabecular spacing in tibia and distal radius.Finite element analysis further confirmed significantly lower stiffness and failure load in tibia.Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity (P ＜0.001).Conclusions The unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone,thus preventing osteoporotic fractures at large in previous studies.However,the inferior structural,densitometric and biomechanical properties at cortical bones,especially femur midshaft,need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures.When patients taking bisphosphonate complain of proximal thigh pain or discomfort,plain X-ray film can be the first line screening.All patients prescribed with bisphosphonate should be informed of such a complication though we must stress its rarity.

BACKGROUNDThe association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones.

METHODSBone mineral density (BMD) at hip and femoral midshaft, bone cross-sectional area, moment of inertia of both femurs, bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly.

RESULTSThe total hip BMD and t-score were found not different between two groups. However, bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft (P < 0.05); morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia (P < 0.01). High resolution-peripheral quantitative computed tomography showed significantly decreased trabecular density, bone volume ratio, trabecular number but increased trabecular spacing in tibia and distal radius. Finite element analysis further confirmed significantly lower stiffness and failure load in tibia. Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity (P < 0.001).

CONCLUSIONSThe unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone, thus preventing osteoporotic fractures at large in previous studies. However, the inferior structural, densitometric and biomechanical properties at cortical bones, especially femur midshaft, need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures. When patients taking bisphosphonate complain of proximal thigh pain or discomfort, plain X-ray film can be the first line screening. All patients prescribed with bisphosphonate should be informed of such a complication though we must stress its rarity.

Aged ; Aged, 80 and over ; Biomechanical Phenomena ; Bone Density ; drug effects ; Bone Density Conservation Agents ; adverse effects ; Bone Remodeling ; drug effects ; Densitometry ; Diphosphonates ; adverse effects ; Female ; Finite Element Analysis ; Humans ; Male ; Middle Aged ; RANK Ligand ; blood

OBJECTIVEThis study aims to explore the clinical applicability and relevance of glycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) for intervertebral disc.

METHODS25 subjects ranging in age from 24 yrs to 74 yrs were enrolled. gagCEST was acquired using a single-slice TSE sequence on a 3T. Saturation used a continuous rectangular RF pulse with B1=0.8 µT and a fixed duration time=1100 ms. Sagittal image was obtained firstly without saturation pulse, and then saturated images were acquired at 52 offsets ranging from ±0.125 to ±7 parts per million (ppm). MR T2 relaxivity map was acquired at the identical location. Six subjects were scanned twice to assess scan-rescan reproducibility.

RESULTSGagCEST intraclass correlation coefficient (ICC) of six subjects was 0.759 for nucleus pulposus (NP) and 0.508 for annulus fibrosus (AF). Bland-Altman plots showed NP had a mean difference of 0.10% (95% limits of agreement: -3.02% to 3.22%); while that of AF was 0.34% (95% limits of agreement: -2.28% to 2.95%). For the 25 subjects, gag CEST in NP decreased as disc degeneration increased, with a similar trend to T2 relaxivity. Gag CEST of AF showed a better correlation with disc degeneration than T2 relaxivity.

CONCLUSIONGagCEST in NP and AF decreased as disc degeneration increased, while gagCEST in AF showed a better correlation than T2 relaxivity.

Adult ; Aged ; Biomarkers ; analysis ; Case-Control Studies ; Female ; Glycosaminoglycans ; chemistry ; metabolism ; Humans ; Intervertebral Disc ; chemistry ; metabolism ; Intervertebral Disc Degeneration ; diagnosis ; metabolism ; Lumbar Vertebrae ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged