Microscopic Magnetic Resonance Imaging Comparing Asymptomatic and Symptomatic Ulnar Collateral Ligament Injuries in Baseball Players.

BACKGROUND: The relationship between abnormalities of the ulnar collateral ligament (UCL) on magnetic resonance imaging (MRI) and elbow symptoms in baseball players remains unclear. PURPOSE/HYPOTHESIS: This study aimed to compare findings of the UCL on microscopic MRI between asymptomatic and symptomatic elbows in baseball players. We hypothesized that the MRI grade of UCL injuries would exhibit no correlation with medial elbow symptoms in baseball players. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: The study participants were skeletally mature baseball players who underwent high-resolution microscopic MRI of the medial elbow including for medical checkups. Elbows with previous surgical treatment or traumatic UCL injuries were excluded. The patients were divided into symptomatic and asymptomatic groups. The UCL appearance on microscopic MRI was categorized into 4 grades and compared between the groups. Abnormal findings in the medial elbow including bony fragments at the medial epicondyle, osteophytes or bony fragments in the sublime tubercle, and bone marrow edema (BME) in the sublime tubercle were also evaluated. RESULTS: A total of 426 baseball players (426 elbows) with a mean age of 20 years (range, 14-41 years) were included. The asymptomatic and symptomatic groups included 158 and 268 elbows, respectively. In the asymptomatic group, based on MRI grading of the UCL, 46 (29%) elbows were rated as grade I, 64 (41%) as grade II, 40 (25%) as grade III, and 8 (5%) as grade IV. In the symptomatic group, 75 (28%) elbows were rated as grade I, 118 (44%) as grade II, 61 (23%) as grade III, and 14 (5%) as grade IV. There was no significant difference in the MRI grades between the groups (P = .9). BME in the sublime tubercle was more frequently seen in the symptomatic group than in the asymptomatic group (P < .001). CONCLUSION: There was no difference in MRI grades of the UCL between symptomatic and asymptomatic elbows in baseball players; approximately 30% of elbows demonstrated high-grade UCL injuries in both groups. BME in the sublime tubercle was more frequently seen in symptomatic elbows than in asymptomatic elbows. BME in the sublime tubercle was a better indicator of symptoms than was MRI grading of the UCL.

Sex differences in factors of pelvis and lower-limb joint kinematics influencing dynamic knee valgus during single-leg squat.

BACKGROUND: Dynamic knee valgus (DKV) during dynamic activity is associated with patellofemoral pain, one of the most common sports disorders, especially in females. No studies have examined the factors that can lead to DKV in females as compared to males while addressing the influence of factors on each other. OBJECTIVE: To identify factors of pelvis and lower joints kinematics affecting DKV during single-leg squat (SLS) in females compared to males with multiple regression analysis. METHODS: Forty-four healthy young people (24 females, 20 males) performed SLS, and pelvis, hip, knee, and ankle 3D kinematics were recorded. The 2D knee frontal plane projection angle (FPPA) was adopted as the DKV measurement. Multiple regression analysis was performed to determine the relationship between FPPA and the kinematics of each joint and segment. RESULTS: Hip adduction and pelvic contralateral rotation were explanatory factors for FPPA in females. Hip adduction, hip internal rotation, and knee external rotation were explanatory factors in males. CONCLUSIONS: The lower limb or pelvic motion factors affecting DKV during SLS differ between the sexes, with pelvic contralateral rotation being extracted only in women, possibly due to differences in pelvic width.

Effect of lateral wedge length on knee adduction moment reduction mechanics during gait.

Lateral wedge insole (LWI) wear is a well-known conservative treatment for patients with knee osteoarthritis and is expected to decrease knee joint loading. Although the effect of LWI length on knee adduction moment (KAM) has been investigated, the biomechanical mechanism has not been fully investigated. Twelve healthy young subjects walked in the laboratory with and without 2 different lengths of LWIs. Three-dimensional motion analysis was performed to calculate the first and second peaks and impulses of the KAM during the stance phase. In addition, the knee-ground reaction force lever arm (KLA) and center of pressure (COP), ankle eversion moment, and ankle eversion angle were calculated. The first peak of KAM was lower, COP was displaced outward, and KLA was shorter with both LWIs attached. On the other hand, the second peak of KAM was lower with longer LWIs, COP was displaced outward, and KLA was shorter. The KAM impulse was significantly smaller in the condition with longer LWI than in the other conditions with smaller ankle eversion motion; longer LWI induced COP to the lateral side through the stance phase and kept KLA short, thus reducing the KAM impulse.

Controlled formation of silica structures using siloxane/block copolymer complexes prepared in various solvent mixtures.

Block copolymers exhibit regularly patterned structures induced by microphase separation. Here we present a method for preparing various particulate silica (SiO2) nanostructures by controlling the microphase separation of block copolymers. In this method, siloxane, a SiO2 precursor, is adsorbed onto poly(4-vinylpyridine) blocks of polystyrene-block-poly(4-vinylpyridine) in solvent mixtures. After siloxane/polymer complexes are coprecipitated via further siloxane polycondensation, the resulting precipitates are heated to remove the polymer. The results of scanning electron microscopy revealed that SiO2 formed various structures including cylindrical, spherical, and lamellar. Different SiO2 nanostructures formed via the microphase separation of siloxane/polymer complexes are prepared simply by varying solvent mixtures without changing the polymer chain. The structural change is interpreted in terms of polymer-solvent interactions and volume fractions in siloxane/polymer complexes.

Young females with hallux valgus show lower foot joint movement stability compared to controls: An investigation of coordination patterns and variability.

BACKGROUND: A kinematic coupling relationship exists between foot joints during gait. In individuals with hallux valgus, forefoot or hallux kinematics may be affected by adjacent or nonadjacent joint motion. Thus, this study aimed to investigate the foot joint coordination pattern and variability during gait in young females with hallux valgus. METHODS: Twenty-five young females with hallux valgus and 25 healthy young females without hallux valgus were enrolled. Reflective markers were attached according to a multisegment foot model. Kinematic data were obtained using a three-dimensional motion analysis system. Joint angles between distal and proximal segments were calculated using analysis software. Foot joint coordination pattern and variability were assessed using a vector-coding technique. FINDINGS: Individuals with hallux valgus had a larger rearfoot relative to shank eversion and forefoot relative to midfoot dorsiflexion during terminal stance and pre-swing compared with those without hallux valgus. There were no significant differences in coordination patterns, but the consistency of coordination between the rearfoot relative to shank motion in the frontal plane and forefoot relative to midfoot motion in the sagittal plane during terminal stance was greater in the hallux valgus group than in the control group. INTERPRETATION: The soft tissue composing the first ray might suffer from more severe stress due to the large motion that occurred with low variability in individuals with hallux valgus. This finding may suggest that the altered kinematics and coordination variability in foot joints are related to hallux valgus biomechanical etiology.

Incidence of teres minor muscle atrophy in young and middle-aged populations.

Background: Teres minor atrophy can be seen in shoulders both with and without a rotator cuff tear, even among the young population. The purpose of this study was to retrospectively investigate the incidence of teres minor atrophy in young and middle-aged patients with or without a rotator cuff tear. Methods: Patient records were reviewed to identify 10-39-year-old patients (Group Y) and 60-69-year-old patients (Group O) who underwent MRI because of shoulder disorders. The exclusion criteria were as follows: (1) prior surgeries, (2) neurological disorders in the cervical spines or shoulder girdle, (3) global atrophy of all four cuff muscles without a rotator cuff tear, (4) acute trauma, and (5) poor image quality due to artifacts. An experienced shoulder surgeon evaluated teres minor atrophy on T1-weighted oblique sagittal images. Statistical analysis was performed using the chi-square test for comparison of Groups Y and O. Results: Group Y consisted of 528 shoulders in 520 patients, including 406 males and 114 females with a mean age of 26 years. Group O consisted of 884 shoulders in 837 patients, including 394 males and 443 females with a mean age of 65 years. Rotator cuff tears were seen in 33 shoulders (6.3 %) in Group Y, and 411 shoulders (46.5%) in Group O. Teres minor atrophy was more present in Group O (59 shoulders [6.7%]) than Group Y (11 shoulders [2.1%], P < .001). Among shoulders with teres minor atrophy, the incidence of intact cuff tended to be higher in Group Y than O (7 shoulders [64%] and 21 shoulders [36%], P = .08). However, the ratio of the intact cuff to the number of patients in each group was not significantly different (Group Y, 7 of 528 [1.3%]; Group O, 21 of 884 [2.3%]). Teres minor muscle atrophy tended to be more common in athletes than nonathletes in Group Y, although the difference was not significant (P = .057). Conclusion: The incidence of teres minor atrophy was significantly higher in middle-aged patients than young patients. Middle-aged patients with teres minor atrophy were more associated with rotator cuff tears. The common cause of teres minor atrophy may be rotator cuff tears. Teres minor atrophy in young patients might be associated with sports-related factors such as infraspinatus hypertrophy or axillary nerve injury.

Relationship between the morphology of the greater tuberosity and radiological and clinical outcomes after arthroscopic rotator cuff repair.

BACKGROUND: Degenerative greater tuberosity (GT) changes are often associated with rotator cuff tears. However, little is known about the impact of GT morphology on surgical outcomes. The aim of this study was to examine the relationship between clinical and radiological outcomes, after rotator cuff repair, and GT morphology. METHODS: We retrospectively investigated shoulders that underwent arthroscopic repair of nontraumatic full-thickness supra-/infraspinatus tears. The exclusion criteria were a lack of either radiographs or magnetic resonance images, revision surgery, partial repair, complications such as infection or dislocation, and follow-up < 2 years. GT morphology on radiographs was classified into 5 groups: normal, sclerosis, bone spur, roughness, and femoralization. The acromiohumeral interval (AHI) was measured on anteroposterior radiographs. Fatty degeneration of the cuff muscles was evaluated using the global fatty degeneration index (GFDI). Postoperative cuff integrity was classified using Sugaya's classification at 2 years after surgery. Clinical outcomes were assessed preoperatively and at postoperative 2 years with the Japanese Orthopaedic Association score and the University of California, Los Angeles shoulder rating scale. RESULTS: The study included 220 shoulders in 212 patients (104 men and 108 women), with a mean age of 66 years (range 43-85). The mean follow-up period was 28 months (range, 24-60 months). Seven shoulders (3.2%) were classified as normal, 65 (29.5%) as sclerosis, 55 (25.0%) as bone spur, 78 (34.5%) as roughness, and 15 (6.8%) as femoralization. The preoperative AHI, in the roughness and femoralization groups, was significantly smaller than that in the sclerosis (P < .01) and bone spur groups (P < .001). The roughness and femoralization groups had a greater number of large tears (P = .006). In the roughness and femoralization groups, mean GFDI was significantly higher than that in the sclerosis group (P < .001 for both). Repaired cuff integrity was not different between all groups, respectively. Both Japanese Orthopaedic Association and University of California, Los Angeles scores improved postoperatively from 73.3 to 95.6 points and 18.2 to 34.0 points (P < .001 for both), respectively, and there were no significant differences between all groups, respectively. CONCLUSION: Roughness or femoralization of the GT was related to larger tears, with smaller AHI and higher GFDI. Repaired cuff integrity and clinical outcomes in shoulders with roughness or femoralization of the GT were not inferior to shoulders with the other types of GT morphologies in this study. Arthroscopic repair can be indicated for shoulders with advanced changes of the GT, if fatty degeneration of the cuff muscles is not severe.

Validation study of novel grading system for ulnar collateral ligament injury of the elbow with high-resolution magnetic resonance imaging.

BACKGROUND: Recently, magnetic resonance imaging (MRI) classification of medial ulnar collateral ligament (UCL) tears has been introduced, but little is known about the relationship between MRI grading and medial joint laxity. It has been reported that microscopy coils could make it possible to achieve high-resolution images of upper extremities with a superior diagnostic ability to conventional MRI. However, there is no report that has compared the diagnostic reliability between microscopic and conventional MRI. The purpose of this study was to assess the relationship between MRI findings and medial joint laxity evaluated with stress ultrasound (US). Secondary objective was to compare the reliabilities of UCL evaluation between microscopic and conventional MRI. METHODS: One-hundred thirty baseball players who underwent MRI of the elbow for the diagnosis of UCL injury using both conventional and microscopy MRI were included in this study. They also underwent stress US for assessment of medial joint laxity against valgus stress. Our MRI grading system for UCL injuries was compared to medial joint laxity evaluated with stress US. The intrarater and interrater reliabilities of our grading system were assessed with both microscopic and conventional MRI. RESULTS: Our grading system was related to valgus stability, especially with microscopic MRI. The reliabilities were fair when combined with microscopic MRI, which exhibited better intrarater and interrater reliabilities than conventional MRI. CONCLUSION: High-resolution microscopic MRI may contribute to the accurate diagnosis of UCL injuries.

Arthroscopic Soft Tissue Stabilization With Selective Augmentations for Traumatic Anterior Shoulder Instability in Competitive Collision Athletes.

BACKGROUND: Many surgeons prefer bony stabilization including Bristow or Latarjet procedures for shoulder instability in collision athletes, even though several potential complications have been reported. There has been a limited number of studies on the midterm outcomes of arthroscopic soft tissue stabilization for anterior shoulder instability in competitive collision athletes. PURPOSE: To assess the outcomes of arthroscopic soft tissue stabilization in combination with selective augmentation procedures for collision athletes with traumatic anterior shoulder instability. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We retrospectively assessed rugby or American football players (<40 years old) who underwent arthroscopic Bankart or bony Bankart repair with selective augmentations (rotator interval closure and/or Hill-Sachs remplissage) for traumatic anterior shoulder instability between January 2012 and March 2017. Shoulders that required other bony procedures were excluded. Recurrence, complications, return to sport, and functional scores (Rowe score and Subjective Shoulder Value sports score) were investigated. RESULTS: This study included 113 shoulders in 100 patients with a mean age of 20 years (range, 15-36 years) at surgery. Rotator interval closure was performed on 36 shoulders in addition to Bankart repair, and rotator interval closure and Hill-Sachs remplissage were performed on 77 shoulders. The mean follow-up period was 44 months (range, 24-72 months). Of the 113 shoulders, 4 (3.5%) experienced postoperative dislocation, but there were no complications. A total of 93 athletes (93%) attained complete or near complete preinjury sports activity levels. The mean Rowe score significantly improved from 36 (range, 10-75) at presurgery to 96 (range, 35-100; P = .003) at postsurgery. The mean Subjective Shoulder Value sports score significantly improved after surgery, from a mean preoperative score of 22 (range, 0-50) to a postoperative score of 92 (range, 64-100; P = .002). CONCLUSION: Our treatment strategy, where arthroscopic soft tissue stabilization was combined with selected augmentations, provided good clinical outcomes for competitive collision athletes in terms of low rates of recurrence and complication, a high rate of return to sports, and good shoulder function.

Muscle co-contraction of ankle joint in young adults in functional reach test at different distances.

PURPOSE: It has been reported that young people may be able to modulate simultaneous contraction depending on the task. The functional reach test (FRT) is widely used as a method to assess dynamic balance. Although there are several reports on the center of pressure (COP), there are few reports on muscle activity and no studies focus on muscle co-contraction during FRT at different distances. We aimed to clarify how the differences in reach distance affect the activity of the lower limb muscles by measuring COP and muscle activity during FRT at different distances. METHODS: Eighteen healthy young adults performed FRT at different distances (maximum, 75%, and 50%) and measured COP and muscle activity of tibialis anterior (TA) and soleus (SOL). Postural control variables were calculated from the COP, and mean muscle activity and muscle co-contraction index (CI) were calculated from muscle activity. Each variable was compared between the reach distance conditions and the correlation between the variable was examined. RESULTS: Most COP variables were significantly higher as the reach distance increased. A significant increase in muscle activity and CI was similarly observed with increasing distance. There was no consistent correlation between COP variables and CI, but there was a positive correlation between TA muscle activity and CI. CONCLUSIONS: The results of the present study showed that the young people used task-specific strategies by modulating lower limb muscle contraction and varying the degree of simultaneous muscle contraction during reaching movements at different distances.

Comparison Between Osteochondral Autograft Transplantation and Arthroscopic Fragment Resection for Large Capitellar Osteochondritis Dissecans in Adolescent Athletes: A Minimum 5 Years' Follow-up.

BACKGROUND: The choice of surgical option for unstable large capitellar osteochondritis dissecans (OCD) lesions in skeletally immature athletes remains controversial. PURPOSE/HYPOTHESIS: The purpose was to investigate functional and radiographic outcomes after arthroscopic fragment resection and osteochondral autograft transplantation (OAT) for unstable large capitellar OCD lesions in skeletally immature athletes with a minimum 5 years' follow-up. We hypothesized that the outcomes after OAT for large capitellar OCD lesions would be superior to those after arthroscopic fragment resection. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 19 elbows in 19 patients (17 male and 2 females) who underwent arthroscopic resection were assigned to group 1 (mean age, 14 years [range, 13-15 years]), whereas 29 elbows in 29 patients (29 male) who underwent OAT were assigned to group 2 (mean age, 14 years [range, 13-15 years]), with the mean follow-up of 8 (range, 5-11 years) and 7 (range, 5-13 years) years, respectively. All OCD lesions were larger than one-half of the radial head diameter. Functional scores, patient satisfaction, and range of motion were compared between the groups. Radiographic changes, including superior migration, radial head enlargement, and osteoarthritis (OA) grade, were examined. RESULTS: All patients returned to sports activity. Functional scores, patient satisfaction, and flexion at the final follow-up were significantly improved in both groups compared with preoperative values, and differences were not significant between groups at the final follow-up. Extension showed a significant improvement in both groups (group 1: -17° to 0°; group 2: -18° to -6°; P < .001). Extension in group 1 was significantly better than that in group 2 at the final follow-up (P = .045). No elbows developed postoperative severe OA in group 1, whereas 3 elbows in group 2 had grade 3 OA; these 3 elbows had preoperative superior migration and radial head enlargement. CONCLUSION: No differences were observed in clinical and radiographic outcomes between patients undergoing arthroscopic fragment resection and OAT, except for elbow extension, at a minimum 5 years' follow-up. We believe that for adolescents with large capitellar OCD lesion, OAT is a good option for skeletally immature elbows and that arthroscopic fragment resection is a reliable and less invasive surgical option for relatively mature elbows.

Nanometer-sized domains in Langmuir-Blodgett films for patterning SiO2.

In this study, we prepared Langmuir-Blodgett films with domains ranging from 20 to 100 nm in size by using perfluorinated fatty acids. The domain size of the obtained LB films is markedly smaller than the ordinary domain size of hydrocarbons and fluorocarbons on the micrometer scale. The domains were prepared by controlling their growth through the addition of 2-propanol to the subphase of Langmuir monolayers. Furthermore, the prepared domains in the LB films were used as templates for patterning SiO(2) films. The obtained SiO(2) films have completely negative structures compared with those of the domains in the LB films.

Superior Labral Injuries in Elite Gymnasts: Symptoms, Pathology, and Outcomes After Surgical Repair.

BACKGROUND: Superior labral anterior-posterior (SLAP) lesions are common among elite gymnasts and throwing athletes. Although SLAP lesions in throwers are well-described in the literature, no study has described the characteristics of SLAP lesions in gymnasts. We aimed to reveal the characteristics of SLAP lesions in gymnasts by comparing the location and extension of these lesions between gymnasts and throwers. HYPOTHESIS: The location and arc of SLAP lesions in gymnasts will be different from those in throwing athletes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study included 27 shoulders in 20 males and 3 females with a mean ± SD age of 20 ± 2.5 years (range, 16-25 years). We performed debridement alone for shoulders with a stable lesion. Anterior and/or posterior labral repair was added for unstable SLAP lesions depending on the extension and stability of the lesions. We investigated symptoms, onset, return to sport (based on patient records), and subjective shoulder values. SLAP lesions were evaluated through use of the Snyder classification. The location and arc of SLAP lesions were determined from surgical records and videos and described by use of the right shoulder clockface method. During the same period, 65 baseball players (65 shoulders; all males; mean age, 23 ± 7.0 years; range, 16-44 years) underwent arthroscopic SLAP surgery. We compared the location and arc of SLAP lesions between gymnasts and baseball players. RESULTS: Symptoms during gymnastics included pain (100%), apprehension (48%), or catching (11%). We found that 20 shoulders had symptom onset during gymnastics, most commonly during rings events. Type II SLAP lesions were found in 17 shoulders, type III in 2 shoulders, and type IV in 8 shoulders. The mean center of SLAP lesions was at the 11:40 clockface position in 27 gymnasts and 10:40 clockface position in 65 baseball players, and the difference was statistically significant (P < .001). The mean arc of SLAP lesions was 125° in gymnasts and 140° in baseball players, and the difference was not significant. We performed debridement in 2 shoulders (7%) and labral repair in 25 shoulders (93%). After surgery, all patients returned to gymnastics. The mean subjective shoulder value was 35 (range, 10-90) preoperatively and 76 (range, 40-100) postoperatively. CONCLUSION: SLAP lesions in gymnasts were significantly located anteriorly compared with those in baseball players. All patients returned to gymnastics after arthroscopic surgery. Secure repair of SLAP lesions may be important for good surgical outcomes, because 50% of patients experienced preoperative shoulder apprehension.

Repair Integrity and Retear Pattern After Arthroscopic Medial Knot-Tying After Suture-Bridge Lateral Row Rotator Cuff Repair.

BACKGROUND: Type 2 failure is a big issue after suture-bridge rotator cuff repair, which may be because of stress concentration at the medial row stitches. We have been performing medial knot-tying after suture-bridge lateral row repair to avoid the stress concentration. This study aimed to evaluate clinical and radiological outcomes after arthroscopic rotator cuff repair using this technique. HYPOTHESIS: This technique would yield better radiological outcomes with a reduced type 2 failure rate compared with reported outcomes after conventional suture-bridge repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The inclusion criteria of this study were (1) full-thickness tears, (2) primary surgery, and (3) minimum 2-year follow-up with pre- and postoperative magnetic resonance imaging (MRI). We investigated active ranges of motion (forward elevation and external rotation), as well as the Japanese Orthopaedic Association (JOA) and University of California, Los Angeles (UCLA), scores preoperatively and at the final follow-up. RESULTS: This study included 384 shoulders in 373 patients (205 men and 168 women) with a mean age of 65 years (range, 24-89 years) at the time of surgery. The mean follow-up was 29 months (range, 24-60 months). There were 91 small, 137 medium, 121 large, and 35 massive tears. Postoperative MRI scans demonstrated successful repair in 324 shoulders (84.4%, group S) and retear in 60 shoulders (15.6%). Among 60 retears, 40 shoulders (67%) had type 1 failure (group F1) and 20 shoulders (33%) had type 2 failure (group F2). Forward elevation and external rotation significantly improved after surgery (P < .001 for both). Postoperative JOA and UCLA scores in group F2 were significantly lower than those in the other groups. CONCLUSION: The medial knot-tying after suture-bridge lateral row repair demonstrated excellent functional and radiological outcomes after surgery, with a retear rate of 15.6%. The type 2 failure showed significantly inferior functional outcomes; however, the rate of type 2 failure was less relative to previous studies using conventional suture-bridge techniques. Our technique could be a good alternative to conventional suture-bridging rotator cuff repair because it may reduce the rate of postoperative type 2 failure.

Measurement of placental oxygenation by transabdominal near-infrared spectroscopy.

The uteroplacental circulation in the placenta can have a major impact on the fetus. Near infrared spectroscopy (NIRS) is the noninvasive method of measuring changes in blood volumes and oxygen concentrations in living tissue. The purpose of this study is to monitor changes in placental tissue oxygen index (TOI) levels, in patients with intrauterine fetal growth restriction during pregnancy, using NIRS. We measured placental TOI values of 15 normal pregnant woman and 15 patients with intrauterine growth restriction admitted to our hospital. The placenta was assessed by ultrasound examination and NIRS was performed on all patients. The TOI values of the IUGR group when hospitalized was 78.6 +/- 1.6 (SD). This value was significantly higher than that of the controls (78.6 +/- 1.6 [SD] versus 70.2 +/- 0.4 [SD]). And the TOI values of the IUGR group, when measured before delivery, were 77.8 +/- 1.6 (SD). The TOI values of the IUGR group before delivery were significantly higher than those of the control group (77.8 +/- 1.6 [SD] versus 70.3 +/- 0.4 [SD]). We propose that NIRS is a candidate, noninvasive method for assessing placental oxygen dynamics on a real-time basis. In the near future it may contribute to perinatal medical practice.