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Lipoma arborescens is a rare synovial lesion characterized by villous proliferation of the synovial membrane and replacement of subsynovial tissue with mature fat cells. The knee joint is the most frequently affected site, particularly in the suprapatellar pouch. However, there have been few reports regarding shoulder involvement, including the glenohumeral joint and subacromial subdeltoid bursa, associated with rotator cuff tear. This article reviews the case of a 67-year-old man who presented with lipoma arborescens of the left shoulder, associated with a rotator cuff tear. Sonography revealed a fluid collection with thickening of the synovial membrane with hyperechoic villous proliferation, located in the subdeltoid bursa. An arthroscopic synovectomy and rotator cuff repair were performed. Arthroscopic findings included yellow frond-like synovial proliferation of the synovium. Postoperatively, the patient was asymptomatic, and the lesion did not recur. Although magnetic resonance imaging is the first-line imaging modality for diagnosis of this lesion, sonography may be used initially for evaluation of chronic joint swelling. In addition, it can be useful for detection of recurrence after synovectomy. This case illustrates the typical sonographic features of lipoma arborescens.

Case A 62-year-old woman with a medical history of nail-patella syndrome (NPS) presented with chronic right shoulder pain. Physical examination revealed that her right shoulder had a restricted range of motion. Radiograph of the shoulder revealed arthritic changes with glenohumeral joint space narrowing, inferior humeral head osteophytes, and posterior glenoid wear. The patient was successfully treated with total shoulder arthroplasty (TSA). The patient had an uneventful postoperative course and was satisfied with her quality of life at the 30-month follow-up. Conclusion TSA may be successfully performed with careful reaming of the hypoplastic glenoid fossa in patients with NPS.

Stress fractures of the first rib occur infrequently in adolescent athletes; therefore, there have been few case reports. Initial radiographs do not always lead to the diagnosis of first rib stress fractures. This study proposed a classification system and a possible mechanism for stress fractures of the first rib using three-dimensional computed tomography (3D-CT). The data of 10 stress fractures of the first rib in adolescent athletes obtained using 3D-CT between 2007 and 2018 were reviewed. Fractures of the first rib were classified according to the location and type of the fracture line. Stress fractures of the first rib were classified into three types: type 1, center-transverse fracture; type 2, center to posterior-oblique fracture; and type 3, posterior-transverse fracture. There were three type 1 fractures, five type 2 fractures, and two type 3 fractures. The fracture lines of types 1 and 2 were on the deep groove of the subclavian artery between the anterior and middle scalene muscle attachments, which is the thinnest and weakest portion of the first rib. However, the fracture line of type 3 was across the posterior part of the first rib and located slightly away from the deep groove of the subclavian artery. A 3D-CT classification of stress fractures of the first rib in adolescent athletes was proposed. Our results suggested that there are three types of the fracture and different mechanisms that cause this type of injury. This classification system helped to implement adequate conservative therapeutic plans based on the proposed mechanism.

Background: Shoulder surgery is performed in the beach chair position (BCP). The systemic arterial blood pressure (BP) must be increased to prevent cerebral hypoperfusion. However, it is not clear how the cardiac function is affected when BP increase to maintain cerebral perfusion pressure in anesthetized patients. Methods: An analysis was performed using the data from 13 patients. We prepared a parallel circuit using a FloTrac Sensor transducer and an arterial BP transducer. Following the transfer of the patient to the BCP under general anesthesia, the FloTrac Sensor transducer was placed at the level of the fourth intercostal space, the arterial BP transducer was placed at the external auditory meatus level. We selected two points before surgery (120 s apart), during which the mean arterial BP (mABP) at the level of the brain was stable and at which the values in the supine position and the BCP were within 5 mmHg. Results: While the patients were in the supine position, the mean mABP at the mid-axillary level was 65.7 mmHg. In the BCP, the mean mABP was 66.5 mmHg at the external auditory meatus and 80.7 mmHg at the fourth intercostal space. The cardiac index changed from 2.2 (supine position) to 2.5 l/min/m2 (BCP). The stroke volume index was significantly increased from 35.8 to 42.3 ml/m2 (P = 0.003). The heart rate changed from 63.0 to 58.6 beats/min. The stroke volume variation was significantly decreased from 12.4% to 8.8% (P = 0.024). Conclusion: In order to ensure patient safety, close attention should be paid to the systemic cardiovascular changes that occur when the BP is increased.

Objectives The aim of this study was to evaluate the relationships among aging, muscle strength, and image feature analysis of the quadriceps femoris muscle and to evaluate the relationship between aging, muscle strength, and sonographic findings. Methods One hundred forty-five healthy volunteers participated in the study. The participants were classified into 6 groups on the basis of sex and age. To assess muscle quality, texture analysis was defined with the following parameters: mean, skewness, kurtosis, inverse difference moment, sum of entropy, and angular second moment. The knee extension force in the sitting position and thickness of the quadriceps femoris muscle were also measured. Results The quadriceps femoris thickness, skewness, kurtosis, inverse difference moment, angular second moment, and muscle strength were significantly decreased in elderly participants versus those in the younger and middle-aged groups (P < .05). In contrast, the mean and sum of entropy were significantly decreased in the younger group compared with the middle-aged and elderly groups. Conclusions Sonography has the capacity to quantitatively assess muscular morphologic changes due to aging and could be a valuable tool for early detection of musculoskeletal disorders.

The aim of this study was to quantitatively assess the echo intensity of the supraspinatus muscle and compare magnetic resonance imaging and ultrasound findings for 27 patients (12 women, 15 men, 65.8 ± 11.5 y). Tear size and fatty infiltration were determined by magnetic resonance imaging; five stages were assigned based on Goutallier's classification. Gray-scale histogram analysis was used for ultrasound assessment, which was performed in both subcutaneous fat and supraspinatus muscle in three different regions; the echo intensity ratio was the ratio of echo intensity in subcutaneous fat to that in the supraspinatus muscle. Sonograms of 27 shoulders revealed 3 shoulders with a partial tear, and 4 with a small tear, 6 with a medium tear, 6 with a large tear and 4 with a massive tear; 4 shoulders had no tear. Supraspinatus muscle echo intensity and echo intensity ratio were significantly lower in the stage 0 and 1 than in stages 2-4. Our study suggests that ultrasound can quantitatively and objectively assess fatty infiltration in the rotator cuff muscle.

Stress fractures of the first rib are uncommon, and few reports have described the occurrence of this injury in overhead-throwing athletes. Furthermore, although there have been a few reports of first rib stress fractures on the throwing side in baseball players, fractures on the nonthrowing side are very rare. Here, we report 2 cases of first rib stress fractures on the nonthrowing side related to swinging of a baseball bat. The cause of the fractures in the present cases may have been repetitive traction and shear force on the first rib resulting from muscle exertion while swinging a bat. Conservative treatment that considered the mechanism of stress fractures resulted in a symptom-free and complication-free return to baseball. The patient's background should be considered for an accurate understanding of the injury mechanism, adequate conservative therapeutic plan, and a successful return to baseball.

Cementless fixation of the femoral stem has been shown to be durable and predictable in total hip arthroplasty (THA), primarily as a result ofrecent improvements in prosthesis geometry and porous surface. Although patients with osteoporotic bone have been considered poor candidates for the use of a cementless femoral component, some recent studies have indicated satisfactory results. However, the indications and selection criteria of cementless stems based on the morphology of the femoral canal have not been established.We aimed to assess and compare the mid-term results of cementless THA with an SL-PLUS® femoral component in patients classified as Dorr types A, B, and C.We evaluated the clinical and radiographic results of primary THA with the cementless SL-PLUS® stem for 34 hips (25 patients). The preoperative femoral bones were classified as Dorr types A, B, and C in 12, 15, and 7 hips, respectively. Implant survival rates were calculated, hip function was evaluated using the Japanese Orthopaedic Association hip score, and radiographic signs were determined from anteroposterior radiographs.The mean follow-up period was 9.4 years (range: 7 to 13 years), and the mean Japanese Orthopaedic Association hip score improved from 43.8 points preoperatively to 85.3 points at the latest follow-up. The overall implant survival rate was 100% at 10 years; radiographic loosening or revision for any reason was used as the endpoint. Third and fourth degrees of stress shielding were observed in 29.4% of cases and were found to be significantly associated with a low cortical index, a Dorr type C femur, and a larger stem size.The use of the SL-PLUS® stem provided satisfactory mid-term clinical and radiographic results in patients with any type of femoral canal morphology.

We describe a case of suprascapular nerve entrapment caused by protrusion of an intraosseous ganglion of the glenoid into the spinoglenoid notch. A 47-year-old man with left shoulder pain developed an intraosseous cyst in the left glenoid, which came into contact with the suprascapular nerve. The area at which the patient experienced spontaneous shoulder pain was innervated by the suprascapular nerve, and 1% xylocaine injection into the spinoglenoid notch under ultrasonographic guidance relieved the pain. Therefore, we concluded that the protrusion of an intraosseous cyst of the glenoid into the spinoglenoid notch was a cause of the pain, and performed curettage. Consequently, the shoulder pain was resolved promptly without suprascapular nerve complications, and the cyst was histologically diagnosed as an intraosseous ganglion. This case demonstrated that the intraosseous ganglion of the glenoid was a benign lesion but could be a cause of suprascapular nerve entrapment syndrome. Curettage is a useful treatment option for a ganglion inside bone and very close to the suprascapular nerve.

Night pain is a particularly vexing symptom in patients with rotator cuff tear. It disturbs sleep and decreases quality of life, and there is no consensus regarding its etiology. Based on arthroscopic surgical observations of synovitis around the rotator interval or capsule surface in rotator cuff tear, we hypothesized that blood flow from the artery feeding the capsule increases blood supply to the synovium. This study aimed to investigate the relationship between blood flow and night pain using pulse Doppler ultrasonography. A series of 47 consecutive patients with rotator cuff tear was evaluated. The peak systolic velocity and resistance index of blood flow in the ascending branch of the anterior humeral circumflex artery were evaluated using pulse Doppler ultrasonography. We also investigated 20 normal shoulders in healthy volunteers. The peak systolic velocity and resistance index were compared between affected and unaffected sides in patients and between dominant and nondominant sides in controls. Anterior humeral circumflex artery peak systolic velocity and resistance index did not differ between sides in control subjects or in patients with rotator cuff tear without night pain. However, anterior humeral circumflex artery peak systolic velocity and resistance index did differ significantly between sides in patients with rotator cuff tear with night pain. This study revealed anterior humeral circumflex artery hemodynamics in patients with rotator cuff tear and normal subjects using Doppler ultrasonography. Night pain, particularly involving aching, appears to be related to the hemodynamics. These findings suggest that investigating the hemodynamics of patients with rotator cuff tear with night pain may lead to greater understanding of the etiology of this symptom.

The patterns and magnitudes of axial femorotibial rotation are variable due to the prosthesis design, ligamentous balancing, and surgical procedures. We aimed to investigate the effects of the weight bearing (WB) condition on the kinematics of mobile-bearing total knee arthroplasty (TKA). We examined 12 patients (19 knees) implanted with a low contact stress (LCS) mobile-bearing TKA system using a two-dimensional to three-dimensional registration technique. The in vivo kinematics of dynamic deep knee flexion under WB and non-WB (NWB) conditions were compared. We evaluated the knee range of motion, femoral axial rotation relative to the tibial component, anteroposterior translation, and kinematic pathway of the femorotibial contact point for both the medial and lateral sides. Under the WB condition, the mean range of motion was 117.8° ± 16.7°. Under the NWB condition, the mean range of motion was 111.0° ± 4.4°. The mean range of axial rotation from full extension to maximum flexion was 3.0° ± 1.5° under the WB condition and 2.2° ± 1.0° under the NWB condition. With regard to the anteroposterior translation, the LCS mobile-bearing TKA system showed the same kinematic patterns under both conditions, except for axial rotation at 0°, 10°, and 110°. From hyperextension to maximum flexion, the kinematic pattern reflected a central pivot under both conditions. In conclusion, this study demonstrated that, in an LCS mobile-bearing TKA system, knee kinematics showed the same patterns under NWB and WB conditions, except for axial rotation at the early phase. Further understanding of knee kinematics could provide us with useful information for future design concepts of TKA implants.

The aim of this study was to evaluate the relationships among aging, muscle strength, and image feature analysis of the quadriceps femoris muscle and to evaluate the relationship between aging, muscle strength, and sonographic findings.One hundred forty-five healthy volunteers participated in the study. The participants were classified into 6 groups on the basis of sex and age. To assess muscle quality, texture analysis was defined with the following parameters: mean, skewness, kurtosis, inverse difference moment, sum of entropy, and angular second moment. The knee extension force in the sitting position and thickness of the quadriceps femoris muscle were also measured.The quadriceps femoris thickness, skewness, kurtosis, inverse difference moment, angular second moment, and muscle strength were significantly decreased in elderly participants versus those in the younger and middle-aged groups (P.05). In contrast, the mean and sum of entropy were significantly decreased in the younger group compared with the middle-aged and elderly groups.Sonography has the capacity to quantitatively assess muscular morphologic changes due to aging and could be a valuable tool for early detection of musculoskeletal disorders.

Although lubricin plays a role in controlling inflammation and pain as well as being a mechanical lubricant, clinical relevance of lubricin concentration in synovial fluid (SF) is unknown. The purpose was to determine whether lubricin concentration in SF is associated with the clinical status of the knee.SF was obtained from 61 knee joints from patients who underwent any knee surgery with several stages of knee osteoarthritis. Lubricin/PRG4 concentration in SF was measured by enzyme-linked immunosorbent assay (ELISA). Clinical evaluations of the knee by the Kellgren and Lawrence (K-L) system, Knee Society Score (KSS), and the range of knee motion, and assessment of joint laxity were performed. Association of lubricin concentration in SF and these clinical factors was statistically analyzed.There was no significant correlation between lubricin concentration in SF and age, sex, K-L grade, or KSS. However, lubricin concentration was significantly correlated with anteroposterior laxity (R = 0.50, p 0.001), full flexion angle (R = 0.39, p 0.01), and range of knee motion (R = 0.38, p 0.01), but not full extension angle, varus laxity, or valgus laxity.Lubricin concentration was correlated with joint flexibility, but not with clinical symptoms, including pain at that time.

The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient’s height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

A collarless, proximally porous-coated type of Spongiosa Metal II hip prosthesis was used for cementless total hip arthroplasty in 52 hips, and 48 hips were followed and assessed during a mean follow-up period of 6.3 years (minimum 5 years). There were 8 hips (16.7%) that had stress shielding, and 2 hips (4.2%) that had thigh pain. In terms of stability, the stem was bony stable in 39 hips, fibrous stable in 6, and unstable in 3. The stability of the stem was significantly correlated with the stem canal filling ratio. It was suggested that the much more proximal transfer of loading stress by a collarless, proximally porous-coated stem is not suitable for the Spongiosa Metal II series because it may unacceptably reduce the stability of the stem.

Ultrasonography (US) is a non-invasive method which can assess not only solid tissue organs but also soft tissues such as tendons and nerves. However, it has not been fully understood that US is a useful tool for the depiction of periarticular structure. We compared the diagnostic accuracies between US and magnetic resonance imaging (MRI) in the patients with rotator cuff tear (RCT). Seventy patients, who underwent arthroscopic surgery, preoperative US and MRI examinations at Gifu University Hospital from January 2010 to April 2013 (49 male, 21 female, mean age 59.7 +/- 15.9) were included in this study. The diagnostic accuracy, sensitivity and specificity of US and MRI were 94.3% and 94.3%, 95.8% and 97.9%, 90.9% and 84.6%, respectively, when the intraoperative finding was regarded as a gold standard. These results suggest that US is useful for the diagnosis of RCT as equal as MRI.

We evaluated the clinical and radiographic results of primary total hip arthroplasty for 81 dysplastic hips (71 patients) using cementless Spongiosa Metal II cups (ESKA Implants, Lubeck, Germany). The mean follow-up period was 6.4 years (minimum 5 years), and the preoperative mean Japanese Orthopaedic Association hip score had improved from 45.2 to 87.4 points at the latest follow-up. The radiographic outcome was no aseptic loosening in all 81 hips. The hip center was located significantly more superior than in the contralateral normal hip in 45 patients, but the difference was less than 10 mm; however, there was no significant difference in the lateral position of the hip center. The use of a Spongiosa Metal II cup for dysplastic hips provided satisfactory 5- to 10-year clinical and radiographic results.

Young athletes who employ overhead arm movements frequently develop shoulder pain caused by muscle tightness or scapula dysfunction1-3. Generally, they are instructed to perform a stretching and muscle-conditioning regimen1,3, but refractory pain without muscle tightness sometimes persists. In such cases, magnetic resonance imaging (MRI) should be used to look for other lesions, and occasionally a cystic lesion may be identified. Cysts located near the labrum, referred to as paralabral cysts or labral cysts, may cause shoulder pain or suprascapular nerve palsy4,5. To our knowledge, there have been no previous reports of ganglion cysts that were located below the coracoacromial ligament as being the cause of shoulder impingement syndrome in athletes. We report the presence of such a cyst in a patient who had the typical symptoms of shoulder impingement syndrome. For diagnostic imaging, we carried out radiographs, MRI, ultrasonography, and cystographic three-dimensional computed tomography (CT) examinations. Ultrasonography was particularly helpful for understanding the movement of the ganglion, while shoulder-dynamic and cystographic three-dimensional CT was very useful for identifying the location of the stalk and estimating the size of the cyst. Our patient was informed that data concerning the case would be submitted for publication, and he consented. A twenty-one-year-old male, right-hand-dominant volleyball player developed pain in the anterior aspect of the right shoulder when spiking the ball. The pain had persisted for more than a year as of the time that the patient presented to our institution, but there was no history of trauma. Physical examination revealed tenderness on compression of the area over the coracoacromial ligament. The examination findings did not suggest shoulder instability, and the patient had no limitation of motion in the shoulder. There was no evidence of local heat, a mass, muscle weakness, or …

Fractures of the first rib occur infrequently in athletes. This report describes a basketball player with thoracic outlet syndrome (TOS) resulting from nonunion of a first rib fracture with a hypertropic callus. Conservative therapy had been ineffective for 1 year after the patient sustained the injury, and he had complained of numbness in the left upper extremity when his shoulder was in abduction and external rotation. We performed resection of the first rib through a transaxillary approach to achieve neurovascular decompression. This resulted in immediate resolution of the symptoms. There was no recurrence of the numbness in the left upper extremity at 2 years after surgery. Previous reports of sports-associated first rib fracture have indicated that it has a relatively good prognosis. However, nonunion of a first rib fracture may lead to TOS that is unresponsive to conservative treatment. Therefore, this type of fracture should be followed-up carefully.

Infection of a hip prosthesis is one of the most severe complications encountered in orthopedic practice. Two-stage reconstruction using an antibiotic-impregnated cement spacer has become a popular procedure for the treatment of this condition. However, there are some disadvantages with the use of antibiotic-loaded cement, including low biocompatibility, a very low release ratio, and the possibility of thermal damage to the antibiotic. We have developed an effective drug delivery system for osteomyelitis in which porous hydroxyapatite (HA) blocks are loaded with an antibiotic by the vacuum method. We report here a modification of this delivery system applied for the first stage of two-stage reconstruction surgery against infected hip prosthesis. Eight consecutive patients who developed hip prosthesis infection underwent two-stage revision total hip arthroplasty (THA) using antibiotic-loaded porous HA blocks prepared by the vacuum method. Thorough debridement and insertion of antibiotic-loaded HA blocks was performed in the first stage, followed by conversion to THA after eradication of infection in the second stage. The mean interval between the stages was 16.8 weeks. There were no complications related to the use of the antibiotic-loaded HA blocks. The patients were followed up for an average of 49 months with no evidence of recurrent infection. The mean Japanese Orthopedic Association hip score improved from 45.1 before surgery to 79.6 at the latest follow-up. This simple approach utilizing antibiotic-impregnated HA blocks prepared by the vacuum method is considered to be effective for treatment of hip prosthesis infection.

Morcellized bone grafting was performed to significant acetabular deficiency in 35 hips of 29 patients in cementless total hip arthroplasty (THA). Bridging trabeculation across the graft–host interface, remodeling of the graft, and trabecular reorientation were observed at 4 weeks, 3.7 months, and 10.7 months postoperatively, respectively. These remodeling processes were observed in all cases. Morcellized bone grafting for acetabular deficiency in cementless THA stock, which is necessary to make the cup stable, revealed encouraging early trabecular reorientation and recovery of acetabular bone even in cases in which structural bone grafting is needed.