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.

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.

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.

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.

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.

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.

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.

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.

Postural stability in patients with anterior cruciate ligament tears with and without medial meniscus tears.

PURPOSE: To compare postural stability in patients with isolated anterior cruciate ligament (ACL) tears and ACL tears with associated meniscal tears. METHODS: Quadriceps and hamstring muscle strength and their ratio, as well as the relationships of these parameters with postural stability, were compared in 23 patients with isolated ACL tears and 27 with combined ACL and medial meniscus tears. Postural stability was determined from the anterior-posterior, medial-lateral, and overall stability indices using the Biodex Stability System. RESULTS: On both the involved and uninvolved sides, there were no differences in mean stability indices, including anterior-posterior, medial-lateral, and overall stability indices, in patients with isolated and combined ACL tears. In patients with isolated ACL tears, both overall (2.3 ± 1.2 vs. 1.8 ± 1.4, p = 0.033) and medial-lateral (1.2 ± 0.6 vs. 1.0 ± 0.5, p = 0.031) stability indices were significantly higher on the involved compared to the uninvolved side. These differences, however, were not observed in the combined ACL tear group. CONCLUSION: No significant differences in postural instability on the affected and unaffected sides were observed in patients with isolated ACL tears and those with combined ACL and medial meniscus tears. These findings indicate that there is no need to reduce the goal of restoring proprioception in patients with combined compared with isolated ACL tears. LEVEL OF EVIDENCE: III.

Deltoid muscle injury scratched by an osteophyte on the greater tuberosity of the humeral head: an unusual cause of shoulder pain.

Few reports to date have discussed acute deltoid muscle injury, including partial or complete deltoid muscle detachment from its origin. The present report describes a different pathomechanism and clinical manifestations of deltoid muscle injury. A 52-year-old man experienced acute severe pain in the right shoulder as a result of abrupt elevation of the arm. The deltoid muscle had apparently been scratched by an osteophyte on the greater tuberosity. After arthroscopic excision of the osteophyte, the symptoms resolved completely.

Ultrasound elastography of lateral epicondylosis: clinical feasibility of quantitative elastographic measurements.

OBJECTIVE: The objective of our study was to investigate the clinical feasibility of ultrasound elastography for assessing patients with lateral epicondylosis and to establish an objective and quantitative method of elastographic measurement in the affected tendon. SUBJECTS AND METHODS: A total of 97 symptomatic and 89 asymptomatic common extensor tendons from both elbows of 79 consecutive patients with lateral epicondylosis and 14 healthy participants were prospectively examined by gray-scale sonography, color Doppler sonography, and compression-based elastography. Real-time color-coded elastography was performed and quantified with two regions of interest: the adjacent subcutis (S1) for a reference area and the common extensor tendon (S2) for the target area. The mean strain ratio (S1/S2) was used for quantitative comparisons. The difference in the mean strain ratio between symptomatic and asymptomatic tendons was assessed with conditional regression analysis. RESULTS: In symptomatic elbows, 87 of 97 tendons (89.7%) showed intratendinous hypoechogenicity, 86 of 97 (88.7%) showed swelling, and 70 of 97 tendons (72.2%) showed intratendinous hyperemia. Color-coded elastography revealed a soft area on 73 of 97 tendons (75.3%). The mean strain ratio was 1.45 (SD, 0.45) for symptomatic tendons and 2.07 (SD, 0.70) for asymptomatic tendons. The mean strain ratio of the symptomatic tendons was significantly lower than that of asymptomatic tendons (p < 0.001), indicating that the symptomatic tendons were softer. CONCLUSION: Our results revealed that patients with lateral epicondylosis had significantly lower strain ratios in their common extensor tendon origins. Ultrasound elastography using quantitative strain ratio measurements could be a promising supplementary method to evaluate tendon abnormalities in lateral epicondylosis.

Synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis: sonographic diagnosis.

Synovial osteochondromatosis is an idiopathic benign metaplasia of the synovial membrane rarely found in an extra-articular bursa. We describe the case of a 55-year-old woman with synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis. Plain radiographs showed a radiopaque mass over the middle facet of the greater tuberosity, suggesting calcific tendinitis. Sonography, however, showed a loose body in the subacromial bursa, and no evidence of calcification inside the rotator cuff.

Correlation between magnetic resonance imaging and clinical impairment in patients with adhesive capsulitis.

OBJECTIVE: To determine the relationship between clinical impairment and MRI findings in patients with adhesive capsulitis. MATERIALS AND METHODS: Contrast-enhanced MRI of 97 patients with a clinical diagnosis of adhesive capsulitis (AC) were retrospectively reviewed. Specific MRI criteria, including thickness and gadolinium enhancement of the joint capsule in the axillary recess and subcoracoid fat obliteration in the rotator interval, were correlated with limited range of motion (ROM) and pain. Other variables considered in this study were rotator cuff pathology, arm dominance, diabetes mellitus, age, and gender. Statistical analysis was performed using logistic and linear regression analysis. RESULTS: Thickening of the joint capsule in the axillary recess correlated with limited external rotation (p < 0.01), gender (p < 0.01) and arm dominance (p < 0.05). Gadolinium enhancement of the joint capsule in the axillary recess correlated with pain intensity (p < 0.05). Subcoracoid fat obliteration in the rotator interval was not correlated with limited ROM or pain. CONCLUSIONS: MRI can be a useful technique to assess several clinical impairment measures in patients with adhesive capsulitis. Thickening and gadolinium enhancement of the joint capsule in the axillary recess on MRI are associated with limited ROM and pain.

Anterior cruciate ligament rupture in gouty arthritis.

A 34-year-old male presented with right knee instability without any trauma. He had been diagnosed with right knee gouty arthritis 2 years prior. An arthroscopic examination revealed abundant calcific material deposited around the knee joint, including in the ACL tissue, and that the ACL was torn at the femoral attachment site. Treatment involved a synovectomy to remove calcific material, followed by an ACL reconstruction. Histology evaluation revealed gouty arthritis with the presence of tophi in the synovium, soft tissue, and ACL tissue. The case presented here indicates the possibility of pathologic rupture of the ACL associated with gouty tophus infiltration of that ligament. Level of evidence IV.

Factors affecting assessment of ulnar bowing in radiography.

BACKGROUND: The "ulnar bow sign" is a novel marker of plastic ulnar deformity with radial head dislocation. This sign is best assessed on true lateral radiographs. However, such radiographs are rarely obtained in routine clinical situations. Misdiagnosis can result from using suboptimum radiographs. The present study examined the clinical radiographs of normal forearms in children to identify factors that affect the assessment of ulnar bowing. METHODS: We retrospectively analyzed the lateral forearm radiographs of 175 normal children ranging in age from 2 to 12 years. Radiographs were classified according to humeral position. The size and direction of the maximum ulnar bow were evaluated. The effect of humeral position, age, sex, and arm side on ulnar bow assessment were analyzed. RESULTS: Of the 175 radiographs, 27 showed a concave dorsal ulnar border (15.4%), 90 showed a straight dorsal ulnar border (51.4%), and 58 showed a convex dorsal ulnar border (33.2%). Only 22 (12.6%) radiographs were found to be true lateral radiographs; the remainder showed evidence of humeral rotation and/or tilting. Humeral tilting was found to affect the assessment of ulnar bowing (P<0.05), whereas the other measured factors did not. CONCLUSIONS: The present study found that humeral tilting at the time of forearm radiography affected the assessment of ulnar bowing. Therefore, physicians should be cautious when assessing ulnar bow in the clinical setting. LEVEL OF EVIDENCE: Level IV.

Virtual Bernese osteotomy using three-dimensional computed tomography in hip dysplasia.

BACKGROUND: Accurate assessment of acetabular morphology and its relationship to the femoral head is essential for planning a periacetabular osteotomy. We observed the acetabular coverage after virtual Bernese osteotomy using computer-aided technique. METHODS: Three-dimensional computed tomography of 18 normal hips and 3 symptomatic dysplastic hips were analyzed. Through the center of the femoral head, vertical images were obtained at 10° intervals from 0° to 180° of rotation, using multiplanar reformation technique. Subsequently we measured 19 center-edge angles (CEAs) from each acetabulum. Four types of virtual osteotomy were performed on the three dysplastic hips. The adequacy of acetabular coverage after osteotomy was determined by comparing CEAs after correction with normal CEAs. RESULTS: Pearson correlation coefficients between the CEAs measured from normal cases and postoperative cases after lateral rotation of osteotomized fragments were 0.906 in case 1, 0.975 in case 2, 0.976 in case 3. Additional anterior rotation increased anterior acetabular coverage and simultaneously decreased posterior coverage in all three cases. CONCLUSION: Computer-aided virtual surgery technique based on three-dimensional computed tomography information enabled acetabular coverage to be quantified preoperatively in Bernese osteotomy. Lateral rotation of osteotomized acetabular fragments improved anterior and posterior coverage as well as lateral coverage.

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.

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.