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Background Diabetes mellitus weakens bone strength due to deterioration of bone quality; however, the histological mechanisms are still unknown. We hypothesized that histological assessment of cortical bone would enable us to determine the cause of the bone strength reduction associated with diabetes mellitus. Our aim was to evaluate the histomorphometric changes of cortical bone associated with deterioration of intrinsic bone properties and bone quality in diabetes mellitus. Methods We compared the outcomes of mechanical tests, bone mineral density measured using micro-computed tomography, and histological assessments, by applying Villanueva’s bone stain, to the tibial bones of 40-week-old diabetic and control male rats. Results With respect to mechanical testing, the maximum load and energy absorption were significantly lower in the diabetic than in the control group, although fracture displacement and stiffness were not significantly different between the two groups. Bone mineral density was significantly higher in the diabetic group than in the control group. Bone histomorphometry revealed that the diabetic rats had fewer osteocytes, greater cortical porosity, and increased mineralization in cortical bone compared with the control group. Conclusions Increased mineralization of the cortical bone with greater cortical porosity leads to a weakening of bone strength in diabetes mellitus.

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.

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.

Although epidemiological studies on epiphyseal injury have been reported, such studies have not been made systematically in Japan. In this study, we examined the incidence of epiphyseal injury in paediatric patients treated at five general hospitals and three private clinics. We treated the patients with limb injuries between January 1992 and December 1997, and reviewed them at least 18 months after the original injuries. The original radiograms and the completed case records were classified according to age and sex of the injured children, site of the fracture, type of treatment, and its complications. Epiphyseal injuries accounted for 17.9% of all paediatric fractures. The most frequently injured epiphysis was the phalanges of hands, 21.9% of all physeal injuries. Salter-Harris type I accounted for 28.6% of physeal injuries; type II (60.9%) revealed the largest number of cases in this study, compared with type III (6.7%) and type IV (3.7%). Type V was not recognized. Most physeal injuries were treated conservatively. Either weight-bearing joints or elbow joints were treated surgically. Complications of physeal injuries were seen in seven cases. Five cases involved the upper limb, and the other two cases involve the lower limb. Although deformity or malfunction caused by physeal injuries was remained, only one case needed a corrective osteotomy. Other six cases revealed a fair prognosis.

Limb lengthening by the callotasis method has been clinically applied to patients who suffered from limb length inequality, micromelia, angular deformation and partial bone defect on long bones. However, this technique was time consuming and led to various complications, such as infection at the pin insertion sites, limitation of the range of motion in adjacent joints, muscular weakness and peripheral neuroparalysis. This study was undertaken to investigate whether alternating current electric (AC) stimulation could shorten the maturation period during callotasis. The tibiae of 20 immature male Japanese white rabbits were osteotomized and fixed with external lengthener (Orthofix M100; Orthofix Srl, Bussolengo, Italy). The experimental schedule lasted 5 weeks consisting of 1 week for the latency period, 2 weeks for distraction and 2 weeks for maturation. Twenty rabbits were equally divided into two groups: the control group and the electrical stimulation (ES) group. The control group was not stimulated with an AC stimulator. The ES group was stimulated for 5 weeks just after osteotomy. The obtained results revealed radiologically, electrophysiologically and histologically that AC stimulation accelerated the maturation of lengthened callus and that it could shorten the time course of callus lengthening.

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.

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.

Background Magnetic resonance imaging has low diagnostic accuracy for subscapularis tendon tears. This study investigated the utility of radial-slice magnetic resonance images for diagnosing subscapularis tendon tears. Materials and methods We investigated 55 shoulders in 54 patients with rotator cuff tears evident during arthroscopic shoulder surgery. The intraoperative finding of a subscapularis tendon tear was compared with the identification of a subscapularis tendon tear on preoperative radial, transverse, and oblique sagittal images using a 3.0-T system. The sensitivity and specificity of diagnostic images generated using different imaging methods for subscapularis tendon tears were investigated. Results A subscapularis tendon tear was present in 38 shoulders (69.1%). When the diagnostic accuracy of the magnetic resonance images was compared with the arthroscopic findings, the radial images had 94.7% sensitivity and 82.4% specificity, the transverse images had 57.9% sensitivity and 100% specificity, and the oblique sagittal images had 60.5% sensitivity and 100% specificity. Conclusion Radial-slice magnetic resonance images have high sensitivity for subscapularis tendon tears and are useful for diagnosing these lesions. In particular, the sensitivity for tears in the superior part of the subscapularis tendon is higher than that of conventional methods.

Objectives: We investigated the effects of electrical stimulation therapy on cutaneous and muscle blood flow in critical limb ischemia patients following regenerative therapy. Methods: Three groups were studied: 10 healthy young subjects, 10 elderly subjects, and 7 critical limb ischemia patients after regenerative therapy. After 5 min rest, electrical stimulation was applied at 5 Hz on the tibialis anterior muscle for 10 min. We estimated the relative changes in oxyhemoglobin and total hemoglobin compared to the basal values at rest (Δ[HbO2], Δ[Hbtot]), which reflected the blood flow in the skin and muscle layer, and we simultaneously measured the tissue O2 saturation (StO2) throughout the electrical stimulation and recovery phase by near-infrared spectroscopy. Results: The Δ[HbO2] and Δ[Hbtot] values of the muscle layer in critical limb ischemia patients increased gradually and remained significantly higher at the 5-min and 10-min recovery periods after the electrical stimulation without reducing the StO2, but there is no significant change in the other two groups. Skin blood flow was not influenced by electrical stimulation in three groups. Conclusion: This improvement of the peripheral circulation by electrical stimulation would be beneficial as the adjunctive therapy after regenerative cell therapy.

Background Magnetic resonance imaging is useful for evaluating the rotator cuff, but some tendinous insertions cannot be assessed using oblique sagittal, oblique coronal, and axial magnetic resonance (MR) images because of the presence of the partial volume effect. Hypothesis The purpose of this study was to determine whether radial-slice MR images could reveal normal rotator cuff insertions and rotator cuff tears more clearly than conventional MR images. Patients and methods The study included 18 subjects with normal rotator cuffs and 30 with rotator cuff tears. MR images of rotator cuff insertions sliced into radial, oblique coronal, and axial sections were obtained. The extent to which normal rotator cuff insertions and rotator cuff tears were visualized in each of the three MR images was evaluated. Results The top to posterior portions of the rotator cuff insertions from 0 ° to 120 ° could be visualized in the radial MR images. In comparison, the posterior portions of the rotator cuff insertions could not be visualized around 45 ° in both the oblique coronal and axial MR images. Discussion These findings demonstrate that radial MR images are superior to the oblique coronal and axial MR images regarding their ability to accurately visualize rotator cuff insertions. Radial MR images also revealed greater detail around 45 ° in the posterior area of the rotator cuff tears than the oblique coronal and axial MR images. Radial MR images are particularly useful for visualizing clinically important posterosuperior rotator cuff tears. Level of evidence Level III – diagnostic study.

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

The anterior band of the inferior glenohumeral ligament is the most important restraint for preventing traumatic anterior glenohumeral instability. The condition of this ligament markedly affects the results of arthroscopic Bankart repair. We compared non-arthrographic magnetic resonance imaging (MRI) in abduction and external rotation and arthroscopic findings of the ligament in 51 shoulders with traumatic anterior glenohumeral instability. The condition of the ligament was evaluated based on the presence of a thick low-signal band between the anterior labrum and the head of the humerus in all magnetic resonance images obtained from the 3- to 5-o'clock position of the glenoid rim (right shoulder). The sensitivity and specificity of the MRI evaluation were 94% and 82%, respectively. MRI in abduction and external rotation is fairly useful for predicting the condition of the ligament in advance of invasive measures (ie, arthroscopy).

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 investigated risk factors for osteonecrosis of the femoral head (ONF) in renal transplant recipients, who are susceptible to the disease. Among 287 renal transplant recipients, 18 ONF patients with enough data were included, and 18 age- and sex-matched recipients without ONF were nominated as reference cases. Risk factors were analyzed using a conditional logistic regression method. There were no differences between the ONF patients and the reference cases regarding the types of immunosuppressant or the donor (living or cadaveric, father or mother, matching blood type and human leukocyte antigens). The daily oral steroid dosage (prednisolone 25.0 mg/day or more) and blood urea nitrogen level 2 months after transplantation were the only factors with relevance to the occurrence of ONF. We propose that oral steroid dosages should be low or reduced after renal transplantation, and acute rejection should be controlled with pulsed therapy.

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.

We investigated the usefulness of a radial-sequence magnetic resonance imaging (MRI) technique in the visualization of the acetabular labrum, which surrounds the acetabulum. In 22 hip joints of 12 volunteers, T2-weighted images were obtained on 24 radial planes of the acetabular rim, set at 15 degrees -intervals, using the small tip angle gradient echo method. We examined 7 planes in the weight-bearing portion. The acetabular labrum in the weight-bearing portion was depicted in good contrast to the surrounding tissues. The shape of the labrum differed among individuals and also in the anterior and posterior portions of the labrum. The signal intensity of the labrum was low or partially moderate. There was a high signal intensity band on the base of the acetabular labrum in several portions, which should be carefully interpreted to avoid confusion with abnormality. We concluded that radial-sequence MRI could be a useful technique for evaluation of the condition of the acetabular labrum in the weight-bearing portion.

Arthroscopic Bankart repair, using staples, requires a thick and wide anterior band of the inferior glenohumeral ligament. We compared MRI and arthroscopic findings of the ligament in 81 shoulders with traumatic anterior glenohumeral instability. When fluid was present in the shoulder, sensitivity and specificity of the MRI evaluation for the presence of a thick and wide ligament were 82% and 100%, respectively. In shoulders without joint fluid, the condition of the ligament was evaluated according to the presence of a low- or moderate-signal triangle structure on the anterior margin of the glenoid cavity in the 3 MR images obtained from the inferior 2 cm of the glenoid. Sensitivity and specificity of the MRI evaluation in cases without fluid were 84% and 93%, respectively. The MR technique needs to be further improved to achieve better sensitivity for preoperative selection of shoulders suitable for Bankart repair with staples.