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Background Post-polio syndrome-induced muscle weakness may develop in limbs that have had normal muscle strength and have been considered unaffected by polio. Objective To investigate the utility of electromyography (EMG) for predicting future muscle weakness in clinically unaffected limb muscles of polio survivors. Design Retrospective study. Setting Academic polio clinic. Participants Polio survivors (N = 77) who underwent EMG between April 2008 and March 2010 and were followed for at least 2 years. Materials and methods Chart reviews were conducted to extract baseline EMG and manual muscle strength test (MMT) results to investigate the relationship between baseline EMG abnormalities and change in muscle strength over 2 years for various upper and lower limb muscles that control movement in the limb joints. Main outcome measurements Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of EMG findings for prediction of subsequent muscle weakness. Results EMG data were available for 44 deltoid, 59 biceps brachii, 60 triceps brachii, 59 vastus lateralis, 59 tibialis anterior, and 55 gastrocnemius (medial head) muscles. The percentage of muscles with an initial MMT of grade 5 that developed weakness over 2 years of follow-up was approximately 15% for most muscle types. Sensitivity of EMG to predict subsequent weakness was higher in the lower limbs (0.67-1.00). Specificity was higher in the biceps brachii (0.83). PPV was higher in the biceps brachii (0.50). NPV was higher in the lower limbs (0.89-1.00) but lower in the deltoid (0.75). Conclusion EMG abnormalities were detected in some clinically normal muscles of polio survivors. EMG abnormalities predicted muscle weakness 2 years later, although the strength of this relationship varied depending on the muscle.

Background Bone mass was recently reported to be related to skeletal muscle mass in humans, and a decrease in cortical bone is a risk factor for osteoporosis. Since circulating myostatin is a factor that primarily controls muscle metabolism, this study examined the role of myostatin in blood in bone mass-skeletal muscle mass interactions. Methods The subjects were 375 middle-aged community residents with no history of osteoporosis or sarcopenia who participated in a health check-up. The subjects were divided into those with low cortical bone thickness (LCT) or low cancellous bone density (LBD) and those with normal values (NCT/NBD). Bone metabolism markers (BAP, TRACP-5b, etc.), skeletal muscle mass, serum myostatin levels, and lifestyle, were then compared between the groups. Results The percentage of diabetic participants and blood HbA1c, TRACP-5b, and myostatin levels were significantly higher, and the frequency of physical activity, skeletal muscle mass, grip strength, and leg strength were significantly lower in the LCT group than in the NCT group. The odds ratio of high myostatin in the LCT group compared with the NCT group was significant (2.26) even after adjusting for related factors. Significant differences were observed in the same items between the LBD and NBD groups as between the LCT and NCT groups, with no significant differences in skeletal muscle mass and serum myostatin levels. The serum myostatin level was significantly negatively correlated with cortical bone thickness and skeletal muscle mass. Conclusions Myostatin may regulate bone-skeletal muscle interactions and serve as a surrogate marker of cortical bone metabolism. Key messages The interaction between bone and skeletal muscle is reported to be important for preserving the activity of bone and muscle metabolism. Herein, we report for the first time that myostatin may regulate bone-skeletal muscle interactions and serve as a surrogate marker of cortical bone metabolism in adults.

Purpose: To identify factors associated with falls in Japanese polio survivors and assess the extent of their impact.Materials and methods: Subjects were 128 polio survivors. Fall history and fear ...

Secular changes in the incidence rate of hip fractures were estimated to vary by fracture type, i.e., femoral neck or trochanteric fractures, age, and sex, in urban or rural areas in Kyoto Prefecture, Japan from 2008 to 2017. PURPOSE Our survey in Kyoto Prefecture from 2008 to 2017 showed that the incidence rate of femoral neck fractures is generally increasing. We investigated the differences between urban and rural areas in the changes of the incidence rate over time of femoral neck and trochanteric fractures during the same period. METHODS Patients aged 65 years and above who sustained hip fractures between 2008 and 2017 and were treated at one of the participating 11 hospitals were included. The ratio of sick beds for acute-term care at the investigated hospitals to total number of beds in the urban area was 16.5% (1863/11,158) and 30.6% (1863/5623) in the rural area. The change in incidence rate was estimated utilizing the population according to the national census conducted in 2010 and 2015. RESULTS There were 3559 and 6474 hip fractures in the urban and rural areas, respectively. Femoral neck fractures were 1936 (54.4%) and 2813 (43.5%) in each area. The increase of the population-adjusted numbers was marked by neck fractures in males, in both areas. In women, there was a significant increase in femoral neck fractures in the urban area in those aged 85 years and over. For trochanteric fractures, a significant increase was only found in women aged 65 to 74 years in the rural area. CONCLUSION A regional difference in the secular changes in incidence rate of hip fractures was found in women, not in men, mostly because neck fractures in women increased in the over 85 group in the urban area.

Summary In Kyoto Prefecture, Japan, the number of hip fractures increased during 2013–2017 compared to 2008–2012. However, the estimated overall incidence rate increased only in femoral neck fractures in men aged ≥75 and women aged ≥85. Purpose The incidence rate of hip fractures in Japan has plateaued or decreased. We investigated the annual hip fracture occurrences in Kyoto Prefecture, Japan, from 2008 to 2017. Methods Patients aged 65 years and above who sustained hip fractures between 2008 and 2017 and were treated at one of the participating 11 hospitals were included. The total number of beds in these institutions was 3701, accounting for 21.5% of the 17,242 acute-care beds in Kyoto Prefecture. The change in incidence rate was estimated utilizing the population according to the national census conducted in 2010 and 2015. Results The total number of hip fractures was 10,060, with 47.5% femoral neck fractures and 52.5% trochanteric fractures. A decrease in number was seen only in trochanteric fractures in the group of 75- to 84-year-old women. The population-adjusted numbers of femoral neck fractures showed a significant increase in all age groups in men, whereas in women, there was an increase in femoral neck fractures in the ≥85 group and trochanteric fractures in the age group 65–74, and a decrease in trochanteric fractures in the age group 75–84. The estimated change in incidence rate showed an increase in femoral neck fractures in men aged ≥75 and women aged ≥85. Conclusion In Kyoto Prefecture, the number of hip fractures increased in the second half of the study period (2013–2017) compared to the first half (2008–2012). However, the incidence rate had not increased, except in femoral neck fractures in men aged ≥75 and women aged ≥85.

Bone mass was recently reported to be related to skeletal muscle mass in humans, and a decrease in cortical bone is a risk factor for osteoporosis. Because circulating myostatin is a factor that primarily controls muscle metabolism, this study examined the role of myostatin in bone mass–skeletal muscle mass interactions. The subjects were 375 middle-aged community residents with no history of osteoporosis or sarcopenia who participated in a health check-up. Cortical bone thickness and cancellous bone density were measured by ultrasonic bone densitometry in a health check-up survey. The subjects were divided into those with low cortical bone thickness (LCT) or low cancellous bone density (LBD) and those with normal values (NCT/NBD). Bone metabolism markers (TRACP-5b, etc.), skeletal muscle mass, serum myostatin levels, and lifestyle were then compared between the groups. The percentage of diabetic participants, TRACP-5b, and myostatin levels were significantly higher, and the frequency of physical activity, skeletal muscle mass, grip strength, and leg strength were significantly lower in the LCT group than in the NCT group. The odds ratio (OR) of high myostatin levels in the LCT group compared with the NCT group was significant (OR 2.17) even after adjusting for related factors. Between the low cancellous bone density (LBD) and normal cancellous bone density (NBD) groups, significant differences were observed in the same items as between the LCT and NCT groups, but no significant differences were observed in skeletal muscle mass and blood myostatin levels. The myostatin level was significantly negatively correlated with cortical bone thickness and skeletal muscle mass. A decrease in cortical bone thickness was associated with a decrease in skeletal muscle mass accompanied by an increase in the blood myostatin level. Blood myostatin may regulate the bone–skeletal muscle relationship and serve as a surrogate marker of bone metabolism, potentially linking muscle mass to bone structure.

BACKGROUND Diabetes decreases bone strength, possibly because of cortical bone changes. Sweep imaging with Fourier transform (SWIFT) has been reported to be useful for cortical bone evaluation. PURPOSE To evaluate cortical bone changes in diabetic rats using SWIFT, assess the usefulness of this technique through comparisons with microcomputed tomography (μCT) and conventional MRI, and clarify the mechanism underlying cortical bone changes using histomorphometry STUDY TYPE: Animal cohort. ANIMAL MODEL 8-week-old male Wistar/ST rats (N = 36) were divided into diabetes (induced by streptozotocin injection) and control groups. FIELD STRENGTH/SEQUENCE 7.04T MRI, SWIFT. ASSESSMENT Six animals from each group were sacrificed at 2, 4, and 8 weeks after injection. Tibial bones were extracted and evaluated using μCT and MRI. The cortical bone mineral density (BMD) was measured using μCT. Proton density-weighted imaging (PDWI) and SWIFT were also performed. The signal-to-noise ratio (SNR) was calculated for each acquisition. The bone formation rate was evaluated using histomorphometry. STATISTICAL TESTS Findings at each timepoint were compared using Mann-Whitney U-tests. RESULTS Cortical BMD was significantly lower in the diabetes group than in the control group only at 8 weeks (P

BACKGROUND Ample evidence on etiological and pathological differences between femoral neck and trochanteric fracture cases suggests the possibility of individualized treatment. There are many issues related to areal bone mineral density and other quantitative computed tomography parameters of the proximal femur. Although osteoporosis is a systemic problem, little has been reported regarding differences in bone structural parameters, including bone mineral density, between them in regions other than the proximal femur. METHODS Participants were consecutive female patients >50 years of age admitted to the Saiseikai Suita Hospital (Osaka prefecture, Japan) for their first hip fracture between January 2012 and September 2014. Cortical thickness (CoTh, mm), volumetric trabecular bone mineral density (TBD, mg/cm3), and elastic modulus of trabecular bone (EMTb, GPa) were obtained as the new QUS parameters using the LD-100 system (Oyo Electric, Kyoto, Japan). The mean values of these parameters were compared between femoral neck and trochanteric fracture cases. In addition, correlations between age and each QUS parameter were investigated for each fracture type. A receiver operating characteristic (ROC) curve analysis was performed to examine the degree of effect each parameter on the fracture types. The area under the curve (AUC) for each parameter was compared to the AUC for age. RESULTS There were 63 cases of femoral neck fracture (mean age, 78.2 years) and 37 cases of trochanteric fracture (mean age, 85.9 years). Mean TBD and EMTb were significantly higher for femoral neck fractures. There were significant negative correlations between QUS parameters and age for femoral neck fractures (P < 0.005). The regression lines for femoral neck fractures were above those for trochanteric fractures for TBD and EMTb. AUCs were 0.72 for age, and 0.61, 0.65, and 0.65 for CoTh, TBD, and EMTb, respectively. CONCLUSIONS The new QUS parameters indicated that TR fracture cases were more osteoporotic than were FN fracture cases, even at the distal radius. There might be systemic differences between them, in addition to localized factors at the proximal femur.

Purpose To evaluate the cortical bone signal-to-noise ratio (SNR) in ovariectomized (OVX) rats during the early postoperative period as a method to measure bone quality using the sweep imaging with Fourier transform (SWIFT) technique. Materials and Methods Twelve-week-old female Sprague–Dawley rats (n = 64) were divided into sham and OVX groups. Preoperative tetracycline was immediately administered subcutaneously to distinguish new cortical bone area, and tibial samples were collected at 2, 4, 8, and 12 weeks postoperatively. Magnetic resonance imaging (MRI) was performed using proton density-weighted imaging (PDWI) and SWIFT to obtain cross-sectional images of the tibial diaphysis. The cortical bone SNR was calculated. Bone histomorphometry was performed. Results Histomorphometry findings showed that the new bone area was significantly greater at 8 and 12 weeks postoperatively in the OVX group (P < 0.05) while the porosity area decreased gradually in both groups (P < 0.001). The difference of SNR receiving PDWI did not reach statistical significance (P = 0.057). The SWIFT technique showed that the SNR was significantly higher at 8 and 12 weeks postoperatively in the OVX group (P < 0.05) and was correlated with the new bone area (R2 = 0.430). Conclusion The SWIFT findings suggest that the SWIFT technique may depict early changes in cortical bone quality. J. Magn. Reson. Imaging 2015;42:128–135. © 2014 Wiley Periodicals, Inc.

Metastatic and primary bone tumors are malignant tumors affecting the skeleton. Although the prognosis of patients with these tumors has improved with the development of effective chemotherapy, the challenges of local recurrence, subsequent osteolysis, degradation of bone strength and unresectable tumors persist. Local control of these tumors is therefore a key strategy to address these limitations. The third-generation bisphosphonate (BP), zoledronic acid (ZOL), has been demonstrated to reduce osteoclasts and exhibited potent antitumor effects in a number of malignancies. Hydroxyapatite (HA) and polymethyl methacrylate (PMMA) bone cement are used in orthopedic surgery as bone graft substitutes, for implant arthroplasty and bone strengthening, and as a sustained-release system for drugs such as antibiotics. At present, the antitumor effects of ZOL-loaded HA in vitro or in vivo or of ZOL-loaded bone cement in vivo have not been described. Therefore, the present study assessed the effects of ZOL-loaded HA and bone cement in malignant tumor cells. The two materials exerted strong antitumor effects against osteosarcoma, fibrosarcoma, synovial sarcoma, renal cancer, prostate cancer and lung cancer cells upon releasing ZOL. The antitumor effects of ZOL-loaded HA were less potent compared with those of ZOL-loaded bone cement, possibly as BPs exhibit higher affinity to HA. ZOL-loaded bone cement also exerted antitumor effects against pulmonary metastases and primary lesions, without exhibiting systemic toxicity in vivo. These results demonstrate that these materials may be beneficial for the treatment of malignant bone tumors, including metastatic bone tumors. In addition, as these materials are already in clinical use, such applications may be easily implemented.

BACKGROUND The incidence of femoral neck and trochanteric fractures reportedly differ by age and regionality. We investigated differences in monthly variations of the occurrence of femoral neck and trochanteric fractures as well as place and cause of injury in the Kyoto prefecture over a 6-year period. METHODS Fracture type (neck or trochanteric fracture), age, sex, place of injury, and cause of injury were surveyed among patients aged ≥ 65 years with hip fractures that occurred between 2008 and 2013 who were treated in 1 of 13 participating hospitals (5 in an urban area and 8 in a rural area). The proportion of sick beds in the participating hospitals was 24.7% (4,151/16,781). Monthly variations in the number of patients were investigated in urban and rural areas in addition to the entire Kyoto prefecture. Place of injury was classified as indoors or outdoors, and cause of injury was categorized as simple fall, accident, or uncertain. RESULTS There were 2,826 patients with neck fractures (mean age, 82.1 years) and 3,305 patients with trochanteric fractures (mean age, 85.0 years). There were similarities in the monthly variation of the number of fractures in addition to the place and cause of injury between neck and trochanteric fractures. Indoors (approximately 74%) and simple falls (approximately 78%) were the primary place and cause of injury, respectively. The place of injury was not significantly different by fracture type with each age group. Significantly more patients with neck fracture had "uncertain" as the cause of injury than trochanteric fracture in all age groups. CONCLUSIONS Based on the results of the present study, the injury pattern might not have a great effect on the susceptibility difference between neck and trochanteric fractures.

Introduction/Background The aim of this study was to reveal the relation between the neurogenetic change in the nonparalytic muscles in upper and lower limbs of Polio survivors and the later muscle strength decline. Material and method Retrospective study. We looked back the data of electromyography (EMG) of Polio survivors in our Polio clinic (average age: 58.9). Muscles whose strength at EMG had been normal were extracted. We looked up the muscle strength at EMG time and two years later from medical record. Results The subjects were 23 deltoid (middle strand), 40 biceps branchii, 36 triceps branchii, 24 vastus lateralis, 19 tibialis anterior, and gastrocnemius (medial head). The ratio of neurogenic change subject (giant spike or interference pattern reduction) was, 30.4%, 25.0%, 36.1%, 62.5%, 47.4%, and 73.7%, respectively. In neurogenic change group of Biceps, 50.0% showed decline in their muscle strength. In non-neurogenic change group of Deltoid, 25.0% showed decline in their muscle strength. Conclusion Present study suggested that some muscle strength decline may be caused by Post-polio syndrome (PPS), and that EMG might be the most useful tool for the risk detection of PPS, especially for Biceps branchii. On the other hand, the fact that 25% of Deltoid non-neurogenic change group showed muscle strength decline was not understood in this study. Pain or disuse from disorder in shoulder joint might possibly be as a cause.

Hip dysplasia is an important cause of osteoarthrosis of the hip, especially in Japanese. Recently, the role of the acetabular labrum in hip diseases has attracted the attention of researchers, but the condition of the labrum in the dysplastic hips has not been described. We used radial MRI to measure the degree of coverage of the femoral head by the acetabulum and the labrum, corresponding to 7 positions on the acetabular rim at every 15 degrees from anterosuperior 45 degrees via midsuperior to posterosuperior 45 degrees. 38 Japanese patients (51 hips) with dysplasia, and 11 healthy controls 122 hips) were studied. In the dysplastic hips, the labrum was larger than in the controls. We found no correlation between the coverage of the acetabulum in the anterosuperior positions and the size of the labrum among the dysplastic hips.

Hip dysplasia is an important cause of osteoarthrosis of the hip, especially in Japanese. Recently, the role of the acetabular labrum in hip diseases has attracted the attention of researchers, but the condition of the labrum in the dysplastic hips has not been described. We used radial MRI to measure the degree of coverage of the femoral head by the acetabulum and the labrum, corresponding to 7 positions on the acetabular rim at every 15 degrees from anterosuperior 45 degrees via midsuperior to posterosuperior 45 degrees. 38 Japanese patients (51 hips) with dysplasia, and 11 healthy controls 122 hips) were studied. In the dysplastic hips, the labrum was larger than in the controls. We found no correlation between the coverage of the acetabulum in the anterosuperior positions and the size of the labrum among the dysplastic hips.

Radial MRI findings and pathological changes were comparatively examined in the acetabular labrum of 11 hips of 11 patients, who underwent total hip arthroplasty for osteoarthritis due to acetabular dysplasia. Diffuse high signal pattern on the radial MR images corresponded to histological degeneration of the labrum. High signal pattern which was equivalent to the synovial fluid, showed an intralabral tear. In the obscure areas of MR images, severe impairment of the labrum such as rupture, detachment, and displacement were found.

Severe osteoarthritis due to acetabular dysplasia (n = 17) was treated with valgus-extension osteotomy, and the patients' clinical outcomes 10-14 years after operation were evaluated according to clinical factors (Japanese Orthopaedic Association hip score; JOA score) and by roentgenography. The mean JOA score 10 years or later had improved by 22 points compared with the preoperative score. On roentgenography, joints which had preoperative roof osteophyte had better postoperative formation of roof osteophyte. The JOA score was higher in the 12 joints which had osteophyte 5 mm or longer than in those joints with osteophyte that was 5 mm or shorter. Postoperative joint space widening occurred in 15 joints (88.2%) 3-6 months postoperatively, and it reached the maximum at 3-5 years. In patients who had a large bone cyst in the femoral head preoperatively, the cyst collapsed, and deformation of femoral head occurred after operation, but remodeling of the joint surface occurred naturally and the congruity improved. In the 6 joints in which the preoperative acetabular head index was less than 60% and the acetabular angle was larger than 30 degrees, the JOA score at 10 years or later was lower than that of the other joints. Based on these findings, valgus-extension osteotomy was evaluated as a useful surgical method for advanced or terminal osteoarthritis in young or middle-aged patients. Predictive factors for long-term prognosis would be the preoperative length of roof osteophyte, joint space widening, and the degree of femoral head covering.

Objective The aim of this study was to investigate the relationship between abnormal acetabular labrum depicted by radial magnetic resonance and progressive joint space narrowing (JSN) of hip dysplasia. Methods Subjects were 23 joints [21 patients; mean age: 35.1 years (16–53 years)] that had acetabular dysplasia with lateral center-edge angle of Wiberg (CE angle) greater than 5° and smaller than 25° (mean, 16.4°), which did not show any arthrotic changes on plain radiograms and were followed up for 3 years or longer. Radial images of acetabular labrum were classified into three stages. Results Progression of JSN was not significantly related to CE angle but to progression of MRI stage ( P =.006). In multivariate analysis, one rank progression of MRI stage was significantly associated with progression of JSN (adjusted OR=11.41, 95% CI: 1.51–86.24, P =.018). Conclusion Our findings showed that in patients whose acetabular dysplasia has 5–25° CE angle, MRI staging based on radial MRI is a better factor for prediction of progression of JSN than CE angle.

To investigate the usefulness of epiphyseal quotient (EQ) measurement for outcome prediction in patients with Legg-Calve-Perthes disease (LCPD), magnetic resonance (MR) imaging was performed in 26 patients with unilateral LCPD within 6 months of the disease onset and subsequently once every 3 months. All the patients were treated conservatively in our institute between 1990 and 1999. The mean follow-up period was 80 months. Clinical outcome was evaluated based on the plain radiograms of the femoral head at the final examination according to Stulberg's classification: the patients whose outcome was class I were regarded as 'excellent' (excellent group), class II as 'good' (good group), and classes III, IV and V as 'poor' (poor group). The excellent group consisted of 10 patients, the good group of 12, and the poor group of four. The EQ measured on MR images (MR-EQ) decreased remarkably in the poor group chronologically, whereas there was no decrease in the excellent group and a slow decrease in the good group. The mean MR-EQ at or before the sixth month (range, 2-6 months; mean, 4.9 months) was 86.2 (range, 76.8-94.8) in the excellent group, 78.3 (57.0-93.4) in the good group, and 67.4 (57.8-74.5) in the poor group (P

We report a case of septic arthritis in the shoulder of an infant treated with a combination of arthroscopic irrigation, debridement, and synovectomy. The results were encouraging. The patient was a boy who was 2 years 6 months of age. His first symptoms were a body temperature of 40 degrees C and right upper arm pain. Five days after the onset, he was brought to our institution. His shoulder was swollen and erythematous. Yellowish fluid (7 ml) was aspirated from his shoulder joint; the causative organism was group A Streptococcus. On admission, arthroscopic surgery was performed. His temperature gradually decreased, and inflammatory markers including the white blood cell count and C-reactive protein level improved. At his 1-year follow-up there was no sign of infection, and a full range of motion in the shoulder was maintained. The interval between the onset and the start of treatment is an important factor affecting the prognosis. The patient was brought to our institution 5 days after onset and underwent arthroscopic surgery on the same day. This early treatment was one of the factors that contributed to a successful result. Arthroscopic surgery, including irrigation and debridement, may be one of the options for treating septic arthritis of an infant's shoulder.

Although crepitus is common in patients with rotator cuff tears, locking is a rare symptom. We encountered a case of repetitive shoulder locking in the elevated position with a longitudinal tear in the supraspinatus tendon and a marked subacromial spur. CASE REPORT A 64-year-old woman had repetitive shoulder locking in the elevated position for several months, preceded by pain and crepitus for 10 years. Locking usually occurred when she elevated her right shoulder and grasped the overhead handrails on buses and trains. On these occasions, she held and shook her right arm with her left hand, which enabled her to adduct the shoulder with snapping. She had no history of trauma around the shoulder but had routinely elevated her shoulder about 90° in her work as a school lunch cook for about 40 years until her retirement 5 years ago. No swelling was observed around the shoulder. Her skin was neither warm nor erythematous. She was obese and had mild diabetes mellitus without any previous medical intervention. Fibrocartilage chondrocalcinosis was apparent in the meniscus of the right knee, the triangular fibrocartilage complex of the right wrist, and the articular disk of the left acromioclavicular joint. Acute crystal-induced arthritis occurred in the right knee 1.5 years after the shoulder surgery mentioned below, and calcium pyrophosphate dihydrate (CPPD) crystals were found in the joint effusion. Her general laboratory data, including serum calcium, phosphate, and uric acid levels, were within normal limits, except that mild hyperglycemia was detected. Radiographs of the right shoulder revealed a marked subacromial spur and a small osteophyte on the undersurface of the acromioclavicular joint. A calcified nodule was present under the acromion. In addition, diffuse calcification was seen in the supraspinatus tendon (Figure 1). Neither spur nor calcification existed in the left shoulder. Arthrograms showed leakage of dye into the subacromial bursa (Figure 2). High signal intensity in the subacromial

We radiographically investigated 36 hips in 34 patients with osteoarthritis of the hip who had undergone total hip arthroplasty. Their mean age was 59.2 years (range 36–79 years), and the mean follow-up period was 11.2 years (range 10–14 years). The long-term outcome and the chronological changes in the bulk autograft were examined. The acetabular component of the prosthesis was a Lord-type threaded cup with a smooth surface. At follow-up, bone absorption was minor in 17 joints, moderate in 11, and major in 8. The hips with graft coverage of ≧20% (group A) had a significantly higher loosening rate than hips with coverage of ≪20% (group B) (P ≪ 0.05). The cup position changed markedly in group A. Our findings indicate that graft coverage should be less than 20% when a bulk graft is used together with a smooth-surfaced cementless cup.

We carried out radial MRI in 30 hips with moderate osteoarthritis and in ten normal hips. On a scout view containing the entire acetabular rim, 12 vertical radial slices were set at 15 degrees intervals. Different appearances were observed in different parts of the joint. In the weight-bearing portion, from 45 degrees anterosuperior to 45 degrees posterosuperior, 'attenuation' (n = 16) and 'disappearance' (n = 25) were observed as abnormalities of the labrum with 'capsular stripping' (n = 29) and 'extraosseous high signal lesion' (n = 27) as capsular abnormalities, seen more often in the anterosuperior portion. In all 12 planes there were osteophytes on the acetabular edge (n = 24), femoral head (n = 22) and/or at the central acetabulum (n = 6), a bone cyst on the acetabulum (n = 18) and/or the femoral head (n = 9), irregularity of the articular cartilage (n = 30), and an effusion (n = 28). Our findings indicate that radial MRI may be a useful non-invasive diagnostic method for demonstrating pathology in moderate osteoarthritis of the hip.

Sequential magnetic resonance imaging (MRI) was performed on a 38-year-old woman with systemic lupus erythematosus who had received corticosteroid and had developed non-traumatic osteonecrosis of the femoral head. The initial MR finding was a band lesion on the T1-weighted image, which had been present before the onset of symptoms. At the onset of symptoms, a diffuse bone marrow edema pattern, with a low signal intensity on T1 and high signal intensity on T2-weighted images, was noted around the band lesion, extending to the femoral neck. Histopathologically, this region was found to consist of serous exudate, focal interstitial hemorrhage, and mild fibrosis, without any evidence of extension of osteonecrosis. It should be noted that extension of a low signal intensity area on MRI after the onset of hip pain may not be the result of the extension of osteonecrosis, but may represent concomitant edema due to collapse.

Background To investigate the differences in the characteristics of femoral neck and trochanteric fractures between urban and rural areas of Kyoto Prefecture in Japan. Methods Fracture type (neck vs. trochanteric), age, sex, place where fracture occurred (indoors vs. outdoors), and cause of injury were surveyed among patients aged ≥65 years who sustained hip fractures between 2008 and 2010 and who were treated at 1 of 13 participating hospitals (5 urban, 8 rural). The ratio of sick beds to total number of beds at the participating hospitals was 19.6% (2,188/11,158) in the urban area and 34.9% (1,963/5,623) in the rural area. We also investigated the incidence of hip fracture in Tango medical district as a representative rural area. Results There were 1,346 neck (mean age, 82.4 years) and 1,606 trochanteric fractures (mean age, 85.0 years). The ratio of neck to trochanteric fractures was higher in the urban area than in the rural area in all age groups (65–74, 75–84, and ≥ 85 years). There were no apparent differences in place or cause of injury. The incidence of hip fracture in the women of Tango medical district was lower than the national average. Conclusions There was a difference in the ratio of neck to trochanteric fractures between urban and rural areas. This difference is estimated to be caused by the high and low incidence of neck fracture in urban and rural areas, respectively.