Evaluation of myostatin as a possible regulator and marker of skeletal muscle-cortical bone interaction in adults.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Usefulness of Sweep Imaging With Fourier Transform for Evaluation of Cortical Bone in Diabetic Rats.

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 < 0.05). At all timepoints, PDWI-SNR showed no significant differences between groups (P = 0.59, 0.70, and 0.82 at 2, 4, and 8 weeks, respectively). SWIFT-SNR was significantly lower in the diabetes group than in the control group (P < 0.05 at 2 and 4 weeks and P < 0.01 at 8 weeks), and the bone formation rate was significantly lower in the diabetes group than in the control group (P < 0.01 for all). DATA CONCLUSION: SWIFT can detect cortical bone changes even before a decline in the cortical BMD in a diabetic model. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:389-397.

New quantitative ultrasound techniques for bone analysis at the distal radius in hip fracture cases: differences between femoral neck and trochanteric fractures.

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.

Differences in monthly variation, cause, and place of injury between femoral neck and trochanteric fractures: 6-year survey (2008-2013) in Kyoto prefecture, Japan.

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.

Cortical bone water changes in ovariectomized rats during the early postoperative period: Objective evaluation using sweep imaging with Fourier transform.

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 (R(2) = 0.430). CONCLUSION: The SWIFT findings suggest that the SWIFT technique may depict early changes in cortical bone quality.

Diagnostic accuracy of magnetic resonance imaging for subscapularis tendon tears using radial-slice magnetic resonance images.

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.

Urban versus rural differences in the occurrence of hip fractures in Japan's Kyoto prefecture during 2008-2010: a comparison of femoral neck and trochanteric fractures.

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.

Histological assessment of cortical bone changes in diabetic rats.

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.

Urban versus rural differences of hip fractures among the elderly in Kyoto, Japan: a 10-year study.

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.

Hip fractures among the elderly in Kyoto, Japan: a 10-year study.

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.

Factors associated with falls in Japanese polio survivors.

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 of falling, lower limb muscle strength, gait ability (determined by walking speed and number of steps per day), post-polio syndrome incidence, and orthosis or walking aid use were assessed, and factors associated with falls were identified using logistic regression analysis.Results: The fall rate was 64%. Fallers (subjects with one or more falls in the preceding 12 months) had low lower limb muscle strength, slow walking speed, high total scores on the Fall Efficacy Scale-International, which assesses fear of falling, and a high orthosis use rate. Knee extension muscle strength on the weaker side was identified as a main factor influencing risk of falls (odds ratio: 0.72, 95% confidence interval: 0.56-0.96). Receiver operating characteristic curve analysis gave a cutoff value for knee extension muscle strength on the weaker side of 0.42 N/kg or lower.Conclusion: Low knee extension muscle strength on the weaker side was associated with falls, but predictive ability using a single internal factor might be poor. It appears that a comprehensive examination, including other factors, is required.Implications for rehabilitationAs polio survivors age, their risk of falling increases.To identify polio survivors who are at risk of falls, it is important to determine the factors associated with falls and their influence on fall risk.The results of this study showed that reduced knee extension muscle strength on the weaker side was a risk factor for falls in polio survivors.To precisely predict the risk of falls in polio survivors, a comprehensive evaluation of both internal and external factors is required.

Usefulness of Electromyography to Predict Future Muscle Weakness in Clinically Unaffected Muscles of Polio Survivors.

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.

Cytotoxic effects of zoledronic acid-loaded hydroxyapatite and bone cement in malignant tumors.

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.

Investigation of the Longitudinal Relaxation Time of Rat Tibial Cortical Bone Using SWIFT.

Sweep imaging with Fourier transform (SWIFT) method has been developed to image tissues with very short T2 values, such as cortical bone. The purpose of this study was to measure the T1 value of the rat cortical bone. It was approximately 120 ms on 7.04T. This result could thus be useful for studying bony tissue according to the SWIFT method in the future.

Association between loss of bone mass due to short sleep and leptin-sympathetic nervous system activity.

BACKGROUND: Sleep has been reported to be an important factor in bone metabolism, and sympathetic nervous system activity has been reported to regulate bone metabolism. In this study, we evaluated the association between sleep, sympathetic nervous system activity, and bone mass. METHODS: The study subjects were 221 individuals (108 males; 113 females; mean age: 55.1±7.0years) divided into two groups: those who slept for less than 6h a day (short sleep [SS] group), and those who slept 6h or longer (normal sleep [NS] group). The groups were compared with regard to lifestyle, cortical bone thickness, cancellous bone density, bone metabolism markers, blood leptin levels, and sympathetic nervous system activity as evaluated by heart rate variability analysis. RESULTS: Significant differences were observed between the two groups in cortical bone thickness, blood TRACP-5b, and leptin levels. The L/H ratio (an index of sympathetic nervous system activity) was higher in the SS group than in the NS group. Significant negative correlations were observed between cortical bone thickness and both the L/H ratio and leptin levels, and a significant positive correlation was observed between the L/H ratio and leptin levels. CONCLUSIONS: Short sleep was associated with a decline in cortical bone thickness due to the promotion of bone resorption and sympathetic nervous system hyperactivity in the middle-aged group. Leptin levels and cortical bone thickness were found to be closely related, suggesting that cortical bone mass may be regulated via interaction with the leptin-sympathetic nervous system.

Relationship between acetabular labrum evaluation by using radial magnetic resonance imaging and progressive joint space narrowing in mild hip dysplasia.

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 degrees and smaller than 25 degrees (mean, 16.4 degrees ), 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 degrees CE angle, MRI staging based on radial MRI is a better factor for prediction of progression of JSN than CE angle.

Incidence of physeal injuries in Japanese children.

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.

Effects of electrical stimulation therapy on the blood flow in chronic critical limb ischemia patients following regenerative therapy.

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.

Effects of alternating current electrical stimulation on lengthening callus.

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.

Usefulness of epiphyseal quotient measurement on magnetic resonance images for outcome prediction in patients with early-stage Legg-Calve-Perthes disease.

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<0.05 among the three groups). According to our results, because all patients having an MR-EQ at or before the sixth month of 75 or higher were classified in the excellent or good groups, it is thought that the ongoing method of treatment can be continued. On the other hand, since half of the patients having an MR-EQ at or before the sixth month of lower than 75 were classified in the poor group and had a high potential for a poor outcome, it is thought that these patients require strict containment therapy, and altering the surgical procedure could be considered depending on the particular patient. It was thought that the MR-EQ is a useful predictive factor of LCPD prognosis.