Effects of humeral head stabilization intervention during aggressive manual passive stretching exercises in patients with painful stiff shoulder: a prospective, comparative study.

BACKGROUND: No reports have been published verifying the effects of manual interventions such as humeral head stabilization on improving function and reducing pain when applying aggressive manual passive stretching in patients with painful stiff shoulders. The purpose of this study was to compare clinical outcomes, such as range of motion, pain, and disability scores, in patients with painful stiff shoulders with and without humeral head stabilization intervention while applying aggressive manual passive stretching. METHODS: Fifty-six patients with painful stiff shoulders were recruited (31 with humeral head stabilization intervention and 25 without such intervention). Clinical outcomes such as active range of motion (A-ROM), pain, and disability scores were evaluated using a goniometer; measurement of activity visual analog scale (A-VAS); and Disabilities of the Arm, Shoulder and Hand (DASH) and Shoulder Pain and Disability Index (SPADI), respectively. RESULTS: All the parameters, A-ROM, A-VAS, and disability scores (DASH and SPADI) were not significantly different between the 2 groups (P > .05) before the intervention. However, after the intervention, the mean difference in A-ROM for flexion, abduction, and external and internal rotation was 18 (95% confidence interval [CI], 14.1-21.7), 31 (95% CI, 24.9-37.4), 17 (95% CI, 13.4-21.4), and 16 (95% CI, 11.6-20.9), respectively. The mean difference in A-VAS and disability scores for DASH and SPADI was -1 (95% CI, -1.5 to -0.8), -27 (95% CI, 32.3 to -22.6), and -23 (95% CI, -27.8 to -18.3), respectively. All of these measurements favored humeral head stabilization. CONCLUSION: During aggressive manual passive stretching in patients with painful stiff shoulders, humeral head stabilization intervention may be more beneficial in improving clinical outcomes such as A-ROM, A-VAS pain levels, and disability scores.

Intravenous Tranexamic Acid Improves Visual Clarity During Synovectomy in Patients Undergoing Arthroscopic Rotator Cuff Repair: A Double-Blind, Randomized Controlled Study.

PURPOSE: To assess the effects of intravenous tranexamic acid (TXA) on visual clarity at various surgical stages and the correlation between the severity of synovitis and bursitis and the grade of visual clarity in patients undergoing arthroscopic shoulder surgery under an interscalene brachial plexus block. METHODS: This double-blind, randomized controlled study included patients undergoing arthroscopic rotator cuff repair. The TXA group underwent injection of a 100-mL mixture of 1,000 mg of TXA and normal saline solution intravenously whereas the control group was administered the same volume of normal saline solution at 10 minutes preoperatively. Visual clarity was rated according to a 3-grade visual clarity scoring system from grade 1 (clear) to grade 3 (poor) at 4 surgical stages (I, intra-articular soft-tissue procedures including synovectomy; II, acromioplasty; III, bursectomy; and IV, greater tuberoplasty). The primary outcome was arthroscopic visual clarity. The secondary outcomes were medications administered for hemodynamic stability, length of hospital stay, and thromboembolic events. RESULTS: Altogether, 63 patients were included in the study; they were divided into the TXA group, comprising 32 patients, and the control group, comprising 31 patients. The TXA group showed significantly better visual clarity than the control group (median [interquartile range], 1 [1-2] vs 2 [1-2]; P = .027) during stage I but not during stages II through IV. Spearman correlation analysis revealed a significant correlation between synovitis and visual clarity grade during synovectomy (correlation coefficient, 0.393; P = .001) but not between bursitis and visual clarity grade during bursectomy. Deep vein thrombosis and pulmonary embolism did not occur in either group. CONCLUSIONS: Intravenous TXA can improve visual clarity during intra-articular soft-tissue procedures, including synovectomy. However, it does not have a significant effect during acromioplasty, bursectomy, and greater tuberoplasty. TXA can be used to improve visual clarity in patients with suspected severe synovitis. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Are Rotator Muscle Performance and Posterior Shoulder Capsule Tightness Related to Glenohumeral Internal Rotation Deficit in Male College Baseball Players?

Background: Posterior inferior capsule (PIC) tightness in the shoulder joint, a known risk factor for shoulder injury, can be assessed using shear-wave ultrasound elastography (SWE). However, to date, the correlation between PIC elasticity and shoulder rotator muscle performance in college baseball players with glenohumeral internal rotation deficit (GIRD) has not been reported. This study aimed to analyze the differences in PIC elasticity measured using SWE and shoulder rotator muscle performance between male college baseball players with and without GIRD. Methods: Twenty-four male college baseball players participated in this study: 10 with GIRD (G group) vs. 14 without GIRD (NG group). PIC elasticity was measured using SWE in the lateral decubitus position. Shoulder rotator muscle performance tests were performed for the internal rotators (IRs) and external rotators (ERs) at an angular velocity of 180°/sec with 90° shoulder abduction using an isokinetic test device. Results: Mean PIC elasticity was significantly greater in the throwing shoulders of the G group than in those of the NG group (4.8 ± 1.2 kPa vs. 3.7 ± 1.2 kPa, p = 0.036). In the throwing shoulders of the G group, compared with those of the NG-group, the ER/IR ratio was significantly lower (35.7% ± 5.0% vs. 55.5% ± 6.2%, p < 0.001) and IR muscle strength was significantly greater (75.0 ± 7.6 Nm kg-1 × 100 vs. 55.7 ± 6.4 Nm kg-1 × 100, p = 0.002). The mean elasticity of the PIC showed a significant negative correlation with the ER/IR ratio in the throwing shoulders of the G group (r = -0.640, p = 0.046). Conclusions: Among the male college baseball players with GIRD, SWE could quantitatively assess PIC tightness, and an imbalance in shoulder rotator muscle strength was found in these baseball players. Therefore, clinicians and therapists need to focus on the restoration of shoulder rotator muscle imbalance in addition to improving internal rotation in these players.

Importance of Initial Peak Torque of the Supraspinatus Muscle during Shoulder Flexion.

Background: Most previous studies have evaluated flexion strength to assess recovery after arthroscopic rotator cuff (RC) repair. However, limited data are available regarding peak torque at the initial angle (iPT) because most studies have measured flexion strength for peak torque (PT), particularly in small- and medium-sized supraspinatus tears. The purpose of this study was to compare conventional PT and iPT to evaluate supraspinatus muscle strength after arthroscopic RC repair in patients with small- and medium-sized supraspinatus tears. Methods: Isokinetic muscle performance testing was performed in 42 patients with small tears and in 47 patients with medium-sized tears. PT and iPT were evaluated before and 1 year after surgery and were recorded at an angular velocity of 60°/sec and 180°/sec with an isokinetic test. Results: PT and iPT were significantly lower in the involved-side shoulders than in the uninvolved-side shoulders (PT: small tear, p < 0.001; medium tear, p < 0.001; iPT: small tear, p < 0.001; medium tear, p < 0.001) in both groups, preoperatively. However, postoperatively, in the involved-side shoulders, PTs were not different in both small- and medium-sized tears (all p > 0.05), but iPTs were significantly lower in the involved-side shoulders (small tear, p < 0.001; medium tear, p < 0.001). iPT was significantly lower in the involved side shoulders in the medium-sized tear group than in the small-sized tear group before and after surgery (p < 0.05). In the small- and medium-sized tear groups, tear size was significantly correlated with preoperative iPT in the involved-side shoulders (small tear: r = -0.304, p = 0.046; medium tear: r = -0.323, p = 0.027). However, pain visual analog scale was significantly correlated with preoperative (small tear: r = -0.455, p = 0.002; medium tear: r = -0.286, p = 0.044) and postoperative (small tear: r = -0.430, p = 0.005; medium tear: r = -0.354, p = 0.021) iPT in the involved-side shoulders. Furthermore, fatty infiltration grade of the supraspinatus muscle and global fatty degeneration index were not associated with preoperative and postoperative PT and iPT in each group (all p > 0.05). Conclusions: iPT is as important as conventional PT in isokinetic testing to assess supraspinatus muscle strength before and after RC repair.

Submolecular Ligand Size and Spacing for Cell Adhesion.

Cell adhesion occurs when integrin recognizes and binds to Arg-Gly-Asp (RGD) ligands present in fibronectin. In this work, submolecular ligand size and spacing are tuned via template-mediated in situ growth of nanoparticles for dynamic macrophage modulation. To tune liganded gold nanoparticle (GNP) size and spacing from 3 to 20 nm, in situ localized assemblies of GNP arrays on nanomagnetite templates are engineered. 3 nm-spaced ligands stimulate the binding of integrin, which mediates macrophage-adhesion-assisted pro-regenerative polarization as compared to 20 nm-spaced ligands, which can be dynamically anchored to the substrate for stabilizing integrin binding and facilitating dynamic macrophage adhesion. Increasing the ligand size from 7 to 20 nm only slightly promotes macrophage adhesion, not observed with 13 nm-sized ligands. Increasing the ligand spacing from 3 to 17 nm significantly hinders macrophage adhesion that induces inflammatory polarization. Submolecular tuning of ligand spacing can dominantly modulate host macrophages.

Manipulating Nanoparticle Aggregates Regulates Receptor-Ligand Binding in Macrophages.

The receptor-ligand interactions in cells are dynamically regulated by modulation of the ligand accessibility. In this study, we utilize size-tunable magnetic nanoparticle aggregates ordered at both nanometer and atomic scales. We flexibly anchor magnetic nanoparticle aggregates of tunable sizes over the cell-adhesive RGD ligand (Arg-Gly-Asp)-active material surface while maintaining the density of dispersed ligands accessible to macrophages at constant. Lowering the accessible ligand dispersity by increasing the aggregate size at constant accessible ligand density facilitates the binding of integrin receptors to the accessible ligands, which promotes the adhesion of macrophages. In high ligand dispersity, distant magnetic manipulation to lift the aggregates (which increases ligand accessibility) stimulates the binding of integrin receptors to the accessible ligands available under the aggregates to augment macrophage adhesion-mediated pro-healing polarization both in vitro and in vivo. In low ligand dispersity, distant control to drop the aggregates (which decreases ligand accessibility) repels integrin receptors away from the aggregates, thereby suppressing integrin receptor-ligand binding and macrophage adhesion, which promotes inflammatory polarization. Here, we present "accessible ligand dispersity" as a novel fundamental parameter that regulates receptor-ligand binding, which can be reversibly manipulated by increasing and decreasing the ligand accessibility. Limitless tuning of nanoparticle aggregate dimensions and morphology can offer further insight into the regulation of receptor-ligand binding in host cells.

Dynamic Ligand Screening by Magnetic Nanoassembly Modulates Stem Cell Differentiation.

In native microenvironment, diverse physical barriers exist to dynamically modulate stem cell recruitment and differentiation for tissue repair. In this study, nanoassembly-based magnetic screens of various sizes are utilized, and they are elastically tethered over an RGD ligand (cell-adhesive motif)-presenting material surface to generate various nanogaps between the screens and the RGDs without modulating the RGD density. Large screens exhibiting low RGD distribution stimulate integrin clustering to facilitate focal adhesion, mechanotransduction, and differentiation of stem cells, which are not observed with small screens. Magnetic downward pulling of the large screens decreases the nanogaps, which dynamically suppress the focal adhesion, mechanotransduction, and differentiation of stem cells. Conversely, magnetic upward pulling of the small screens increases the nanogaps, which dynamically activates focal adhesion, mechanotransduction, and differentiation of stem cells. This regulation mechanism is also shown to be effective in the microenvironment in vivo. Further diversifying the geometries of the physical screens can further enable diverse modalities of multifaceted and safe unscreening of the distributed RGDs to unravel and modulate stem cell differentiation for tissue repair.

Correlation of glenohumeral internal rotation deficit with shear wave ultrasound elastography findings for the posterior inferior shoulder capsule in college baseball players.

BACKGROUND: The glenohumeral internal rotation deficit (GIRD), primarily caused by the tightness of the posterior capsule, is a major risk factor for shoulder injuries in overhead throwing athletes. Quantitative evaluation of posterior capsular thickness and tightness can help determine the relationship between the posterior inferior capsule and GIRD. One previous study has assessed posterior capsule tightness using shear wave elastography (SWE), in college baseball players; however, it did not address the cutoff value of capsular elasticity that could be considered as abnormal capsular tightness. We aimed to re-evaluate effectiveness of SWE in quantifying posterior shoulder capsule tightness in college baseball players and determine the cutoff value of abnormal capsular elasticity that can predict impending throwing-related shoulder injuries associated with GIRD. METHODS: Twenty-four college baseball players were enrolled in this study. External and internal rotation of the shoulder joint was assessed. The participants were classified into the GIRD group if their throwing shoulder showed >20° of internal rotation loss compared with their nonthrowing shoulder. In a longitudinal ultrasonographic scan of the posterior inferior capsule, shear wave (SW) velocity and thickness were measured at the point nearest to the labrum on both shoulders. RESULTS: Of the 24 subjects, 6 had a GIRD. The mean value of the SW velocity in the throwing shoulder was greater in the GIRD group than in the non-GIRD group (P = .006). The SW velocity difference between the throwing and nonthrowing shoulder was also greater in the GIRD group than in the non-GIRD group (P < .001). There was no significant difference in the thickness of the posterior inferior capsule between both groups. In correlation analysis, the difference in the SW velocity was more strongly correlated with the GIRD than with the SW velocity in the throwing shoulder. When we assume that a 20° GIRD is indicative of a shoulder at risk, the cutoff SW velocity in the throwing shoulder is 4.81 m/s and the SW velocity difference is 0.77 m/s. CONCLUSION: The SW velocity is closely associated with posterior shoulder capsular tightness and may be of quantitative value in baseball players.

Which muscle performance can be improved after arthroscopic Bankart repair?

BACKGROUND: There are no published reports available regarding neuromuscular control recovery in nonathletic patients after arthroscopic (A/S) Bankart repair. This study aimed to compare neuromuscular control and performance of the rotator cuff muscles between patients who underwent A/S Bankart repair and normal controls. METHODS: In total, 32 nonathletic patients who underwent A/S Bankart repair were compared with 32 asymptomatic nonathletic volunteers. Neuromuscular control index (time to peak torque and acceleration time), muscle strength ratio, muscle strength, and muscle endurance of the internal rotators (IRs) and external rotators (ERs) were measured using an isokinetic device at an angular velocity of 180°/s, with 90° shoulder abduction. RESULTS: The neuromuscular control indices of both IRs and ERs were significantly lower in patients who underwent A/S Bankart repair than in normal controls (time to peak torque, IRs: 1059 ± 143 ms vs. 679 ± 226 ms, P = .011; ERs: 595 ± 286 ms vs. 379 ± 123 ms, P = .044; acceleration time, IRs: 75 ± 16 ms vs. 62 ± 15 ms, P = .039, ERs: 70 ± 19 ms vs. 54 ± 18 ms, P = .047). Muscle endurance was significantly lower in patients who underwent A/S Bankart repair than in normal controls (IRs: 670 ± 1 J vs. 718 ± 2 J, P = .002, ERs: 422 ± 6 J vs. 501 ± 2 J, P = .044). The neuromuscular control index showed a significant negative correlation with muscle endurance for both IRs and ERs after the operation (IRs: r = -0.737, P = .003, ERs: r = -0.617, P = .019). CONCLUSION: Compared with normal controls, patients who underwent A/S Bankart repair did not show complete recovery of neuromuscular control of IRs and ERs, although their muscle strength ratio and muscle strength had fully recovered.

Effectiveness of Ultrasound in Evaluation of Fatty Infiltration in Rotator Cuff Muscles.

BACKGROUND: This study aimed to verify the diagnostic performance of Ultrasonography (US) in the evaluation of fatty infiltration (FI) in rotator cuff muscles and to analyze the diagnostic values of each measurement component. METHODS: The degree of FI in 108 shoulders was assessed by magnetic resonance imaging (MRI) and US. MRI findings were graded by the Goutallier classification. US findings were graded by the Strobel method. Agreement between MRI and US findings was evaluated. The sensitivity and specificity for detecting FI and intraobserver reliabilities were also assessed. RESULTS: US grading of the infraspinatus based on short-axis architecture showed good agreement (κ = 0.62). US grading-based on architecture showed good agreement for both supraspinatus and infraspinatus in long- and short-axis scans (supraspinatus, κ = 0.63; infraspinatus, κ = 0.68), while that based on echogenicity showed moderate agreement (supraspinatus, κ = 0.51; infraspinatus, κ = 0.50). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detecting advanced FI were significant in both axes. CONCLUSIONS: US is effective for detecting advanced FI in the rotator cuff muscles. US can assess the infraspinatus more accurately than the supraspinatus, and architecture is a more decisive component of FI status than echogenicity.

Time to peak torque and acceleration time are altered in male patients following traumatic shoulder instability.

BACKGROUND: Numerous authors have evaluated the strength of the rotator cuff muscles in patients with shoulder instability. However, only limited data are available with regard to neuromuscular control in patients with traumatic anterior shoulder instability, in particular at 90° of abduction. This study was designed to assess muscle strength and neuromuscular control ability using time to peak torque and acceleration time in nonathletic patients with traumatic anterior shoulder instability. METHODS: Isokinetic muscle performance testing was performed in 20 male nonathletic anterior shoulder instability patients compared with 20 side-matched asymptomatic volunteers. Isokinetic muscle performance testing was performed at an angular velocity of 180°/s with 90° of shoulder abduction. Muscle strength and neuromuscular control (time to peak torque and acceleration time) of the internal rotators (IRs) and external rotators (ERs) were measured. RESULTS: There were no significant differences in muscle strength of the IRs and ERs between the 2 groups. The injured shoulder showed delayed neuromuscular control in both the IRs and ERs in the instability patients compared with the normal control subjects (time to peak torque, P = .023 for IRs and P = .020 for ERs; acceleration time, P = .035 for IRs and P = .021 for ERs). CONCLUSION: The neuromuscular control of both the IRs and ERs was decreased in male nonathletic patients with traumatic anterior shoulder instability even though muscle strength was not altered. Therefore, clinicians and therapists should implement exercises that aim to restore neuromuscular control in the rehabilitation of nonathletic patients with anterior shoulder instability.

Can Shoulder Muscle Activity Be Evaluated With Ultrasound Shear Wave Elastography?

BACKGROUND: Quantitative assessment of rotator cuff muscle activity is important in the treatment of shoulder disorders. However, the known methods for assessing rotator cuff muscle activity thus far have been inaccurate, invasive, and inconvenient. QUESTIONS/PURPOSES: (1) Does the activity of the deltoid, supraspinatus, and infraspinatus muscles measured using ultrasound shear wave elastography have a linear correlation with muscle activity assessed using generally used methods, including isokinetic dynamometry and electromyography? (2) Does the activity of the deltoid, supraspinatus, and infraspinatus muscles measured using shear wave elastography show good intraobserver and interobserver reliability? METHODS: Twelve volunteers participated in intrasession reliability experiments. They were asked to perform isometric abduction, external rotation, and scaption contractions (defined as elevation of the arm within the plane of the scapula with neutral arm rotation) gradually increased from 0% to 75% of maximal voluntary contraction. The joint torque, electromyographic activity, and shear elastic modulus were synchronously measured in the middeltoid, supraspinatus, and infraspinatus muscles. The validity of the elastic modulus value was assessed using regression analysis between normalized torque and electromyographic root mean square values. For intraobserver and interobserver reliability measurements, repeated experiments were performed with the same protocol. RESULTS: The shear elastic modulus and normalized joint torque with isokinetic dynamometry showed a linear relationship in all muscles (deltoid, supraspinatus, and infraspinatus) and each of the ultrasonography planes (longitudinal and transverse) (mean R > 0.8 and p < 0.001 for all measurements). For the supraspinatus muscle, the mean slope of the relationship between shear elastic modulus in the longitudinal plane and the normalized joint torque during scaption contraction was 1.28 ± 0.39 kPa/%MVC (mean R = 0.93 ± 0.21, p < 0.001). Furthermore, similar results were obtained in relation to electromyography root mean square values (mean R > 0.8 and p < 0.001 in all measurements). For the supraspinatus muscle, the mean slope of the relationship between shear elastic modulus in the longitudinal plane and electromyographic (EMG) root mean square was 0.96 ± 0.27 kPa/%EMG (mean R = 0.91 ± 0.08, p < 0.001). The intraobserver and interobserver reliabilities were excellent in all positions (abduction, external rotation, and scaption) and in both the longitudinal and transverse ultrasonography planes (all intraclass correlation coefficients are > 0.85). CONCLUSIONS: Shoulder muscle activity can be noninvasively evaluated with ultrasound shear wave elastography. Clinician and scientists should consider the application of this technique in cases in which evaluation of shoulder muscle activity is required. The next step after this study will be to check the shear elastic modulus of rotator cuff muscle in patients with rotator cuff tear. We plan to evaluate the correlation between shear elastic modulus and joint torque according to tear size and fatty infiltration status of rotator cuff muscle. CLINICAL RELEVANCE: Shear wave electrography can be used to measure various tissue elasticities in both static and dynamic modes. It may be a useful tool to evaluate pre- and postoperative rotator cuff muscle activity in a relatively simple manner. Shoulder function after reverse total shoulder arthroplasty associated with deltoid muscle activity also may be evaluated. Changes in tissue tightness in shoulder disorders caused by increase soft tissue stiffness (ie, adhesive capsulitis and glenohumeral internal rotation deficit) can be evaluated.

Lower shoulder abduction during throwing motion may cause forceful internal impingement and decreased anterior stability.

BACKGROUND: Internal impingement and decreased anterior stability, which result from shoulder capsular loosening, are common shoulder pathologies in throwing athletes. The purpose of this study was to assess the effect of shoulder abduction angle on shoulder internal impingement and anterior shoulder stability during the simulated throwing motion. METHODS: Eight cadaveric shoulders were tested by simulating the late-cocking and acceleration phases of the throwing motion for intact and thrower's shoulder conditions. The maximal glenohumeral external rotation, anterior translation, location of the rotator cuff insertion with respect to the glenoid, length and site of internal impingement, and glenohumeral contact pressure were measured. All data were compared between shoulder abduction angles of 80°, 90°, and 100°. RESULTS: Decreasing shoulder abduction in the simulated late-cocking phase shifted the humeral head posteriorly (P < .03) and superiorly (P < .001), decreasing the total internal impingement area between the greater tuberosity and glenoid (P = .04) and increasing the glenohumeral contact pressure during internal impingement (P = .02). In the simulated acceleration phase, anterior glenohumeral translation significantly increased as the shoulder abduction angle decreased (P < .001). CONCLUSION: Decreasing shoulder abduction significantly increased the contact pressure during internal impingement in the simulated late-cocking phase of the throwing motion. During the simulated acceleration phase of the throwing motion, anterior glenohumeral translation significantly increased as shoulder abduction decreased.

The Characteristics of Shoulder Muscles in Archery Athletes.

BACKGROUND: This study evaluated the shoulder girdle muscle characteristics of elite archery athletes and provides suggestions for archery training programs. METHODS: This study enrolled 15 cases of high level archery athletes (7 males, 8 females) and 30 cases of (15 males, 15 females) sex, age-matched, healthy, non-athletic individuals. We measured peak torques of flexion (FL), extension (EX), abduction (ABD), adduction (ADD), external rotation (ER) and internal rotation (IR) of both shoulders at an angular velocity of 30°/sec, 60°/sec, and 180°/sec. The peak torques and peak torque ratios of FL/EX, ABD/ADD, and ER/IR of the two groups were compared. RESULTS: The archer group had a greater peak torque of IR and ADD, but only in the left shoulder (p<0.05). In the same group, both shoulders had greater peak torque of EX and lower peak torque of FL. The peak torque ratios of FL/EX of both shoulders were significantly lower in the archer group at all three angular velocities (p<0.05). The peak torque ratios of ABD/ADD were significantly greater in only the left shoulder of the archer group (p<0.05). CONCLUSIONS: The prominent characteristics of the shoulder girdle muscles of an elite archer are stronger adductor muscles of the bow shoulder and stronger extensors of both shoulders, as compared to healthy, non-athletic individuals. These muscle groups of the shoulder probably contribute a major role in maintaining the accuracy and stability during archery shooting. Hence, a training program that selectively enhances the adductor and extensor muscles could prove helpful in enhancing the archery skills of the athlete.

Ultrasound-guided injection for De Quervain's disease: Accuracy and its influenceable anatomical variances in first extensor compartment of fresh cadaver wrists.

BACKGROUND: This study was designed to evaluate the accuracy of ultrasound-guided injection targeting EPB tendon sheath and influenceable anatomical variances to the accuracy in the first extensor compartment of fresh cadaver wrists. METHODS: Thirty wrists of 15 cadavers were used. The wrists were divided into right-sided wrists (control group) and left-sided wrists (group A) to compare the accuracy of the manual injection technique (control group) and ultrasound-guided injection technique (group A) targeting EPB tendon sheath. To estimate the influence of anatomical variances within first extensor compartment to the accuracy of each injection techniques, control group (manual injection group) was divided into Control group I (right-sided wrists without septum) and II (right-sided wrists with septum) and group A (ultrasound-guided injection group) was also divided into group AI (left-sided wrists without septum) and group AII (left-sided wrists with septum), respectively. After the methylene blue dye injection, the location of methylene blue dye and anatomical variances in the first extensor compartment was identified by dissection. RESULTS: The accuracy was higher in the group A (93.3%) than in control group (40.0%, p < 0.05). The accuracy in control group I (55.6%) was higher than in control group II (16.7%, p < 0.05). The accuracy between group AI (100%) and group AII (85.7%) was not significantly different (p > 0.05). Wrists with more EPB or APL tendon slips showed a tendency not to have septum and all intratendinous injections was occurred in the wrist with 1 EPB tendon slip or 1 or 2 APL tendon slip. CONCLUSIONS: Ultrasound-guided injection targeting EPB tendon ensures correct needle placement through the visualization of compartmental anatomy and improves accuracy of injection though the septum in first extensor compartment encourage inaccurate injections.

What Is the Critical Value of Glenoid Bone Loss at Which Soft Tissue Bankart Repair Does Not Restore Glenohumeral Translation, Restricts Range of Motion, and Leads to Abnormal Humeral Head Position?

BACKGROUND: A general consensus has been formed that glenoid bone loss greater than 20% to 25% is the critical amount at which bony augmentation procedures are needed; however, recent clinical results suggest that the critical levels must be reconsidered to lower values. PURPOSE: This study aimed to find the critical value of anterior glenoid bone loss when a soft tissue repair is not adequate to restore anterior-inferior glenohumeral translation, rotational range of motion, or humeral head position using a biomechanical anterior shoulder instability model. STUDY DESIGN: Controlled laboratory study. METHODS: Eight cadaveric shoulders were tested with a customized shoulder testing system. Range of motion, translation, and humeral head position were measured at 60° of glenohumeral abduction in the scapular plane under a total of 40-N rotator cuff muscle loading in the following 11 conditions: intact; soft tissue Bankart lesion and repair; Bankart lesion with 10%, 15%, 20%, and 25% glenoid bone defects based on the largest anteroposterior width of the glenoid; and soft tissue Bankart repair for each respective glenoid defect. Serial osteotomies for each percentage of bone loss were made parallel to the long axis of the glenoid. RESULTS: There was significantly decreased external rotation (121.2° ± 2.8° to 113.5° ± 3.3°; P = .004), increased anteroinferior translation with an externally applied load (3.0 ± 1.2 mm to 7.5 ± 1.1 mm at 20 N; P = .008), and increased posterior (0.2 ± 0.6 mm to 2.7 ± 0.8 mm; P = .049) and inferior shift (2.9 ± 0.7 mm to 6.6 ± 1.1 mm; P = .018) of the humeral head apex in the position of maximum external rotation after soft tissue Bankart repair of a 15% glenoid defect compared with the repair of a Bankart lesion without a glenoid defect, respectively. CONCLUSION: Glenoid defects of 15% or more of the largest anteroposterior glenoid width should be considered the critical bone loss amount at which soft tissue repair cannot restore glenohumeral translation, restricts rotational range of motion, and leads to abnormal humeral head position. CLINICAL RELEVANCE: The critical level of anterior glenoid bone loss at which bony restorations should be considered is closer to 15% of the largest anteroposterior width of glenoid for defects perpendicular to the superoinferior glenoid axis, which is lower than the commonly accepted threshold of 20% to 25%.

Disparity between Clinical and Ultrasound Examinations in Neonatal Hip Screening.

BACKGROUND: For early detection of developmental dysplasia of the hip (DDH), neonatal hip screening using clinical examination and/or ultrasound has been recommended. Although there have been many studies on the reliability of both screening techniques, there is still controversy in the screening strategies; clinical vs. selective or universal ultrasound screening. To determine the screening strategy, we assessed the agreement among the methods; clinical examination by an experienced pediatric orthopedic surgeon, sonographic morphology, and sonographic stability. METHODS: From January 2004 to June 2009, a single experienced pediatric orthopedic surgeon performed clinical hip screenings for 2,686 infants in the neonatal unit and 43 infants who were referred due to impressions of hip dysplasia before 3 months of age. Among them, 156 clinically unstable or high-risk babies selectively received bilateral hip ultrasound examinations performed by the same surgeon using the modified Graf method. The results were analyzed statistically to detect any correlations between the clinical and sonographic findings. RESULTS: Although a single experienced orthopedic surgeon conducted all examinations, we detected only a limited relationship between the results of clinical and ultrasound examinations. Ninety-three percent of the clinically subluxatable hips were normal or immature based on static ultrasound examination, and 74% of dislocating hips and 67% of limited abduction hips presented with the morphology below Graf IIa. A total of 80% of clinically subluxatable, 42% of dislocating and 67% of limited abduction hips appeared stable or exhibited minor instability on dynamic ultrasound examination. About 7% of clinically normal hips were abnormal upon ultrasound examination; 5% showed major instability and 3% showed dysplasia above Graf IIc. Clinical stability had small coefficients between ultrasound examinations; 0.39 for sonographic stability and 0.37 for sonographic morphology. Between sonographic stability and morphology, although 71% of hips with major instability showed normal or immature morphology according to static ultrasound examination, the coefficient was as high as 0.64. CONCLUSIONS: Discrepancies between clinical and ultrasound examinations were present even if almost all of the exams were performed by a single experienced pediatric orthopedic surgeon. In relation to screening for DDH, it is recommended that both sonographic morphology and stability be checked in addition to clinical examination.

Acute Primary Hematogenous Osteomyelitis in the Epiphysis of the Distal Tibia: A Case Report With Review of the Literature.

Osteomyelitis originating in the epiphysis of the long bones is quite rare and is usually found at either the distal femur or the proximal tibia. We report the case of a 12-year-old male with epiphyseal osteomyelitis that had developed in the distal tibia. To the best of our knowledge, this is the first published case report. The patient's history of a trauma that resembled an ankle sprain had delayed the diagnosis and subsequently led him to develop septic arthritis. The ankle is a common site of simple trauma; however, epiphyseal osteomyelitis is rare at this site. Therefore, if the symptoms continue or worsen after trauma, the clinician should check the affected site and take a more aggressive approach to make an early diagnosis.

Diagnosis of adhesive capsulitis: comparison of contrast-enhanced MRI with noncontrast-enhanced MRI.

OBJECTIVE: To compare the diagnostic performance of contrast-enhanced (CE) magnetic resonance imaging (MRI) and non-CE MRI for adhesive capsulitis (AC). METHODS: CE MRI of 50 AC and 53 non-AC patients were reviewed by two radiologists independently. RESULTS: Axillary capsular thickening and T2 hyperintensity (sensitivity=92-94%; specificity=53-64%) and enhancement of the axillary capsule and rotator interval (sensitivity=92-98%; specificity=38-64%) were helpful in diagnosing AC. Interobserver reliability was highest with axillary joint capsule enhancement (κ=0.92). CONCLUSION: Non-CE and CE MRI are helpful in confirming the clinical diagnosis of AC. CE-MRI may improve assessment of the rotator interval and diagnostic confidence in patients with AC.

Status of the contralateral rotator cuff in patients undergoing rotator cuff repair.

BACKGROUND: Although the prevalence of rotator cuff tear (RCT) in the general population has been analyzed, little information is available on the status of the opposite-side rotator cuff in patients who have undergone arthroscopic rotator cuff repair. PURPOSE/HYPOTHESIS: To identify the characteristics of the contralateral shoulder and to identify factors associated with RCT of the contralateral shoulder in patients who underwent surgery for symptomatic RCT. The hypothesis was that the prevalence of RCT in the contralateral shoulder would be higher in patients with increasingly larger cuff tears requiring surgical intervention. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The study cohort consisted of 140 patients with RCT who underwent arthroscopic rotator cuff repair. Opposite-shoulder rotator cuff tendons of all patients were evaluated by ultrasonography. Demographic information and factors related to contralateral RCT were investigated, and risk factors associated with contralateral RCT were assessed. RESULTS: Of the 140 patients who underwent arthroscopic rotator cuff repair, 54 (38.6%) had an RCT of the contralateral shoulder. Of 51 patients with partial-thickness and small-sized full-thickness tears of the operated shoulder, 35 (68.6%) had no tears; 14 (27.5%) had partial-thickness tears; and 2 (3.9%) had small-sized full-thickness tears of the contralateral shoulder. Of 75 patients with medium-sized full-thickness tears, 43 (57.3%) had no tears; 12 (16%) had partial-thickness tears; and 20 (26.7%) had full-thickness tears of the contralateral shoulder. Of 14 patients with large to massive full-thickness tears, 8 (57.1%) had no tears; 1 (7.1%) had a partial-thickness tear; and 5 (35.7%) had full-thickness tears of the contralateral shoulder. The prevalence of RCT of the contralateral shoulder differed significantly among groups classified by tear size (P=.007). The mean American Shoulder and Elbow Surgeons score was significantly lower in the RCT than in the nontear group (55.8±16.9 vs 61.6±13.3; P=.03). Of 29 subjects with symptomatic tears involving the nondominant arm, 17 (58.6%) had contralateral asymptomatic RCT, compared with 37 of 111 (33.3%) subjects with symptomatic tears involving the dominant arm (P=.007). CONCLUSION: The prevalence of RCT of the contralateral asymptomatic shoulder tends to be higher in patients with more symptomatic RCT on one side, in patients with medium-sized or larger RCT in the operated shoulder, and in patients with symptomatic RCT in the nondominant arm.