Asymptomatic Contralateral Shoulder Research Articles

Shoulder muscle activity after latissimus dorsi transfer in an active elevation.

After latissimus dorsi transfer (LDT), an increase in scapulothoracic (ST) contribution in thoracohumeral (TH) elevation is observed when compared to the asymptomatic shoulder. It is not known which shoulder muscles contribute to this change in shoulder kinematics, and whether the timing of muscle recruitment has altered after LDT. The aim of the study was to identify which shoulder muscles and what timing of muscle recruitment are responsible for the increased ST contribution and shoulder elevation after LDT for a massive irreparable posterosuperior rotator cuff tear (MIRT). Thirteen patients with a preoperative pseudoparalysis and MIRT were recruited after LDT with a minimum follow-up of 1 year. Three-dimensional electromagnetic tracking was used to assess maximum active elevation of the shoulder (MAES) in both the LDT and the asymptomatic contralateral shoulder (ACS). Surface electromyography (EMG) tracked activation (% EMG max) and activation timing of the latissimus dorsi (LD), deltoid, teres major, trapezius (upper, middle and lower) and serratus anterior muscles were collected. MAES was studied in forward flexion, scapular abduction and abduction in the coronal plane. In MAES, no difference in thoracohumeral motion was observed between the LDT and ACS, P=.300. However, the glenohumeral motion for MAES was significantly lower in LDT shoulders F(1,12)=11.230, P=.006. The LD % EMG max did not differ between the LDT and ACS in MAES. A higher % EMG max was found for the deltoid F(1,12)=17.241, P=.001, and upper trapezius F(1,10)=13.612, P=.004 in the LDT shoulder during MAES. The middle trapezius only showed a higher significant difference in % EMG max for scapular abduction, P=.020 (LDT, 52.3±19.4; ACS, 38.1±19.7).The % EMG max of the lower trapezius, serratus anterior and teres major did not show any difference in all movement types between the LDT and ACS and no difference in timing of recruitment of all the shoulder muscles was observed. After LDT in patients with a MIRT and preoperative pseudoparalysis, the LD muscle did not alter its % EMG max during MAES when compared to the ACS. The cranial transfer of the LD tendon with its native %EMG max, together with the increased %EMG max of the deltoid, middle and upper trapezius muscles could be responsible for the increased ST contribution. The increased glenohumeral joint reaction force could in turn increase active elevation after LDT in a previous pseudoparalytic shoulder.

Shoulder kinematics and muscle activity following latissimus dorsi transfer for massive irreparable posterosuperior rotator cuff tears in shoulders with pseudoparalysis.

The aim of this study was to evaluate the thoracohumeral (TH) and glenohumeral (GH) motion with muscle activity after latissimus dorsi transfer (LDT) in a shoulder with a massive irreparable posterosuperior rotator cuff tear (MIRT) and pseudoparalysis compared with the asymptomatic contralateral shoulder (ACS). We recruited and evaluated 13 patients after LDT in a shoulder with preoperative clinical pseudoparalysis and an MIRT on magnetic resonance imaging, with a minimum follow-up period of 1 year, and with a Hamada stage of 3 or less. Three-dimensional electromagnetic tracking was used to assess shoulder active range of motion in both the LDT shoulder and the ACS. The maximal active elevation of the shoulder (MAES) was assessed and consisted of forward flexion, scapular abduction, and abduction in the coronal plane. Maximal active internal rotation and external rotation were assessed separately. Surface electromyography (EMG) was performed to track activation of the latissimus dorsi (LD) and deltoid muscles during shoulder motion. EMG was scaled to its maximal isometric voluntary contraction recorded in specified strength tests. In MAES, TH motion of the LDT shoulder was not significantly different from that of the ACS (F1,12=1.174, P=.300) but the GH contribution was significantly lower in the LDT shoulder for all motions (F1,12=11.230, P=.006). External rotation was significantly greater in the ACS (26°±10° in LDT shoulder vs. 42°±11° in ACS, P<.001). The LD percentage EMG maximum showed no significant difference between the LDT shoulder and ACS during MAES (F1,11=0.005, P=.946). During maximal active external rotation of the shoulder, the LDT shoulder showed a higher percentage EMG maximum than the ACS (3.0%±2.9% for LDT shoulder vs. 1.2%±2.0% for ACS, P=.006). TH motion improved after LDT in an MIRT with pseudoparalysis and was not different from the ACS except for external rotation. However, GH motion was significantly lower after LDT than in the ACS in active-elevation range of motion. The LD was active after LDT but not more than in the ACS except for active external rotation, which we did not consider relevant as the activity did not rise above 3% EMG maximum. The favorable clinical results of LDT do not seem to be related to a change in LD activation and might be explained by its effect in preventing proximal migration of the humeral head in active elevation.

The latissimus dorsi tendon functions as an external rotator after arthroscopic-assisted transfer for massive irreparable posterosuperior rotator cuff tears.

Latissimus dorsi tendon transfer is a surgical option for the treatment of massive irreparable posterosuperior rotator cuff tear. Whether a favourable clinical outcome is due to the latissimus dorsi muscle contraction rather than the passive tenodesis effect remains to be confirmed. The purpose of the current case-control study was to evaluate the shoulder kinematics and latissimus dorsi activation after latissimus dorsi tendon transfer. Eighteen patients suffering from irreparable rotator cuff tear that underwent latissimus dorsi tendon transfer and 18 healthy individuals were examined using a 3D kinematic tracking system and electromyography. Active maximal flexion-extension and abduction-adduction of the humerus were measured for the operated and the contralateral shoulder of the patients and the shoulder of healthy individuals to evaluate the range of motion (ROM) and scapulohumeral rhythm. Electromyographic comparison of isometric contraction between the latissimus dorsi of the operated and contralateral shoulder was carried out. After arthroscopic-assisted latissimus dorsi tendon transfer, patients showed comparable flexion and abduction ROM to their asymptomatic contralateral shoulders and to the shoulders of healthy individuals. Significantly higher scapular ROM values were found between the latissimus dorsi tendon transfer side and the shoulders of healthy individuals. While performing external rotation with 0° shoulder abduction, a greater percentage of the electromyographic peak value (p = 0.047) and a higher latissimus dorsi internal/external rotation ratio (p = 0.004) were noted for the transferred muscle in comparison to the contralateral shoulder. Although the arthroscopic-assisted latissimus dorsi tendon transfer failed to normalize scapulothoracic joint movements of patients, a functional latissimus flap and a shoulder ROM similar to the contralateral side or the shoulder of healthy individuals can be expected after this procedure in patients with massive irreparable posterosuperior rotator cuff tear. III.

Differences in scapular upward rotation, pectoralis minor and levator scapulae muscle length between the symptomatic, the contralateral asymptomatic shoulder and control subjects: a cross-sectional study in a Spanish primary care setting

ObjectiveTo determine the potential differences in both scapular positioning and scapular movement between the symptomatic and asymptomatic contralateral shoulder, in patients with unilateral subacromial pain syndrome (SAPS), and when compared...

Shear Wave Ultrasound Elastographic Evaluation of the Rotator Cuff Tendon.

(1) Assess the association between the B-mode morphologic appearance and elasticity in the rotator cuff tendon using shear wave elastography (SWE). (2) Assess the association between SWE and symptoms. Institutional Review Board approval and informed consent were obtained. A retrospective review identified 21 studies in 19 eligible patients for whom SWE was performed during routine sonographic evaluations for shoulder pain. Evaluations were compared with 55 studies from 16 asymptomatic volunteers and 6 patients with asymptomatic contralateral shoulders. Repeated studies were accounted for by resampling. Proximal and distal tendon morphologic characteristics were graded from 1 to 4 (normal to full-thickness tear), and average shear wave velocity (SWV) measurements were obtained at both locations. In 68 examinations, deltoid muscle SWV measurements were available for post hoc analysis. The morphologic grade and SWV showed weak-to-moderate negative correlations in the proximal (P < .001) and distal (P = .002) rotator cuff tendon. A weakly significant SWV decrease was found in the proximal tendon in symptomatic patients (P = .049); no significant difference was seen in the distal tendon. The deltoid muscle SWV showed weak-to-moderate negative correlations with the morphologic grade in the proximal (P = .004) and distal (P = .007) tendon; the deltoid SWV was also significantly lower in symptomatic shoulders (P = .001). Shear wave elastography shows tendon softening in rotator cuff disease. It captures information not obtained by a morphologic evaluation alone; however, a poor correlation with symptoms suggests that SWE will be less useful in workups for shoulder pain than for preoperative assessments of tendon quality. Deltoid muscle softening seen in morphologically abnormal and symptomatic patients requires further exploration.

Three-dimensional shoulder kinematics normalize after rotator cuff repair

Patients with a rotator cuff (RC) tear often exhibit scapular dyskinesia with increased scapular lateral rotation and decreased glenohumeral elevation with arm abduction. We hypothesized that in patients with an RC tear, scapular lateral rotation, and thus glenohumeral elevation, will be restored to normal after RC repair. Shoulder kinematics were quantitatively analyzed in 26 patients with an electromagnetic tracking device (Flock of Birds) before and 1 year after RC repair in this observational case series. We focused on humeral range of motion and scapular kinematics during abduction. The asymptomatic contralateral shoulder was used as the control. Changes in scapular kinematics were associated with the gain in range of motion. Shoulder kinematics were analyzed using a linear mixed model. Mean arm abduction and forward flexion improved after surgery by 20° (95% confidence interval [CI], 2.7°-36.5°; P = .025) and 13° (95% CI, 1.2°-36.5°; P = .044), respectively. Kinematic analyses showed decreases in mean scapular protraction (ie, internal rotation) and lateral rotation (ie, upward rotation) during abduction by 3° (95% CI, 0.0°-5.2°; P = .046) and 4° (95% CI, 1.6°-8.4°; P = .042), respectively. Glenohumeral elevation increased by 5° (95% CI, 0.6°-9.7°; P = .028) at 80°. Humeral range of motion increased when scapular lateral rotation decreased and posterior tilt increased. Scapular kinematics normalize after RC repair toward a symmetrical scapular motion pattern as observed in the asymptomatic contralateral shoulder. The observed changes in scapular kinematics are associated with an increased overall range of motion and suggest restored function of shoulder muscles.

Three-Dimensional Scapular Kinematics in Patients with Reverse Total Shoulder Arthroplasty during Arm Motion.

BackgroundThere have been few reports on altered kinematics of the shoulder after reverse total shoulder arthroplasty (RTSA). We investigated differences in 3-dimensional (3D) scapular motions assessed using an optical tracking system between RTSA treated shoulders and asymptomatic contralateral shoulders during arm motion.MethodsThirteen patients who underwent RTSA were assessed for active arm elevation in 2 distinct elevation planes (sagittal plane flexion and scapular plane abduction). Their mean age was 72 years (range, 69 to 79 years) and the mean follow-up was 24.4 months (range, 13 to 48 months). The dominant side was the right side in all the 13 patients, and it was also the side treated with RTSA. Scapular kinematics was recorded with an optical tracking system. The scapular kinematics and the scapulohumeral rhythm (SHR) of the RTSA shoulders and asymptomatic contralateral shoulders were recorded and analyzed during arm elevation.ResultsThere were no significant differences in internal/external rotation and anterior/posterior tilting of the scapula between shoulders during arm motion (p > 0.05). However, upward rotation of the scapula differed significantly during arm motion (p = 0.035 for sagittal plane flexion; p = 0.046 for scapular plane abduction). There were significant differences in the SHR between the two shoulders (p = 0.016 for sagittal plane flexion; p = 0.021 for scapular plane abduction).ConclusionsThe shoulder kinematics after RTSA showed significant differences from the contralateral asymptomatic shoulders. Increased upward rotation and decreased SHR after RTSA indicate that RTSA shoulders use more scapulothoracic motion and less glenohumeral motion to elevate the arm.

Ultrasound Dimensions of the Rotator Cuff and Other Associated Structures in Korean Healthy Adults.

In evaluating patients complaining of shoulder pain, ultrasonography is an emerging imaging tool due to convenience, low cost, high sensitivity and specificity. However, normative values of ultrasound dimensions of the shoulder to be compared with pathologic findings in Korean adults are not provided yet. We evaluated the ultrasound dimensions of the rotator cuff, long head of biceps tendon, deltoid muscle and acromioclavicular joint in Korean healthy adults. Shoulder ultrasonography was performed on 200 shoulders from 100 healthy adults. The dimensions of the thickness of rotator cuff (supraspinatus, infraspinatus, subscapularis tendon), deltoid muscle, long head of biceps tendon, subacromial subdeltoid bursa, and acromioclavicular joint interval were measured in a standardized manner. Differences in measurements among sex, age, and dominant arms were compared.The thickness of rotator cuff tendons (supraspinatus, infraspinatus, subscapularis) and deltoid muscle were significantly different between men and women. The thickness of subacromial subdeltoid bursa was significantly different between men and women for non-dominant side. In rotator cuff tendon measurements, the differences between dominant and non-dominant shoulders were not significant, which means the asymptomatic contralateral shoulder can be used to estimate the normal reference values. When stratified by age divided by 10 years, the measurements of supraspinatus, subscapularis and deltoid thickness showed tendency of increase with the age. The acromioclavicular joint interval, on the other hand, revealed decreasing tendency. This report suggests normative values of ultrasound dimensions of healthy Korean population with varying age, and can be useful as reference values in evaluating shoulder pathology, especially in rotator cuff tendon pathology.

Ultrasound dimensions of the rotator cuff in young healthy adults

No studies have looked at the rotator cuff dimensions in the young healthy population using ultrasonography. Our aim is to define the ultrasound dimensions of the rotator cuff in the healthy young adult population and explore correlations with other patient characteristics. Thirty male and 30 female healthy volunteers (aged 18-40years), with no shoulder problems, underwent ultrasound assessment of both shoulders by a musculoskeletal radiologist. The dimensions of the rotator cuff, deltoid, and biceps were measured in a standardized manner. A total of 120 shoulders were scanned. The mean maximum width of the supraspinatus footprint was 14.9mm in men and 13.5mm in women (P<.001). The mean thickness of the supraspinatus tendon was 4.9mm in women and 5.6mm in men. The mean thickness of the subscapularis was 4.4 in men and 3.8mm in women and for the infraspinatus was 4.9mm in men and 4.4mm in women. There was no correlation between height, weight, biceps, or deltoid thickness with any tendon measurements. Apart from supraspinatus tendon thickness, the difference between dominant and nondominant shoulders in the same sex was not significant for any other tendon dimensions. This study has defined the dimensions of the rotator cuff in the young healthy adult, which has not been previously published. This is important for the documentation of normal ultrasound anatomy of the rotator cuff and also demonstrates that the asymptomatic contralateral shoulder can and should be used to estimate the expected dimensions.

Measurement of volumetric bone mineral density in proximal humerus using quantitative computed tomography in patients with unilateral rotator cuff tear

The first purpose of this study was to reveal the clinically important region-specific volumetric bone mineral density (vBMD) of the proximal humerus in patients with unilateral rotator cuff tear (RCT), and the second was to evaluate the relationship between vBMD of the proximal humerus and BMD of the hip and lumbar spine measured using conventional dual-energy X-ray absorptiometry. Finally, we assessed whether any clinical factor could predict local osteoporosis of the proximal humerus. The study enrolled 65 patients who underwent arthroscopic repair of a unilateral RCT between April 2010 and July 2011 and had computed tomography scans of bilateral proximal humeri. Considering the suture bridge technique for RCT repair to be the leading treatment, region-specific BMD was measured in 7 volumetric blocks in the proximal humerus. Image and quantification processing was used to calculate the vBMD of each block. The vBMD values in all 7 blocks of the symptomatic shoulder were significantly lower than those of the asymptomatic contralateral shoulder (P < .05). Regardless of RCT, the greater tuberosity showed significant location-dependence in vBMD value; that is, the vBMD value was the highest in the posterolateral portion and the lowest in the medial portions. No significant correlation was found between vBMD of the greater tuberosity and clinical factors except female gender. The present study demonstrated the regional and bilateral differences in vBMD within the greater tuberosity in patients with unilateral RCT. Aside from female gender, no other clinical factors presented as risk factors for a higher possibility of osteoporosis.

Pit above the lesser tuberosity in axial view radiography

This study examined the relationship between the presence of a pit above the lesser tuberosity on axial view radiographs and rotator cuff tears and compared the demographic data between groups according to the presence of a pit above the lesser tuberosity. The hypothesis of this study was that the radiographic finding of a pit above the lesser tuberosity is related to rotator cuff tears. For 112 patients with a symptomatic rotator cuff tear, plain radiographs of the symptomatic shoulder (tear side radiographs) and plain radiographs of the asymptomatic contralateral shoulder (no-tear side radiographs) were assessed. Seventeen radiological findings, including a pit above the lesser tuberosity, osteophytes, subchondral cysts, and sclerosis, were recorded by one blinded observer. Demographic data such as age, duration of symptoms, sex, arm dominance, smoking history, trauma history, American Shoulder and Elbow Surgeons score, Constant score, and involved tendon were collected. A pit above the lesser tuberosity was noted on tear side radiographs of 40 patients (35.7 %) and on the no-tear side radiographs of 27 patients (24.1 %), representing a significant difference (P = 0.040). A pit associated with a rotator cuff tear was observed more often in the dominant arm (P = 0.040) and more often in patients with less previous trauma (P = 0.024). A pit above the lesser tuberosity on axial view radiography was associated with a rotator cuff tear and occurred more often in the dominant arm of patients who had no trauma history. Prognostic study, Level III.

Thickening of the inferior glenohumeral capsule: an ultrasound sign for shoulder capsular contracture

The aim of this retrospective study was to measure the inferior glenohumeral capsule thickness of shoulders clinically affected by capsular contracture by comparison to the contralateral asymptomatic side. Bilateral shoulder ultrasound (US) examinations of 20 patients with clinically or MRI proven unilateral capsular contracture were retrospectively assessed. Inferior capsule evaluation was performed with a transducer placed within the axilla in maximally abducted shoulders. Measurements were symmetrically performed orthogonally to the inferior glenohumeral ligament (IGHL) in the axial plane; the coronal plane was used to ensure the tension of the IGHL. The significance of any difference in thickening was assessed with the Mann-Whitney test. The average thickness was 4.0 mm in shoulders with capsular contracture vs. 1.3 mm in asymptomatic contralateral shoulders (P < 0.0001). Twenty per cent of patients with capsular contracture and inferior capsule thickness increase showed US features of other painful diseases of the rotator cuff. The thickness of the inferior capsule is measurable through ultrasound examination and appears to be increased in shoulders with capsular contracture. Exploration of the inferior aspect of the shoulder joint could be added to shoulder US examination protocols for capsular contracture assessment even if other rotator cuff abnormalities are diagnosed by US. • Ultrasound is increasingly used to diagnose shoulder problems. • The thickness of the inferior glenohumeral ligament is measurable in the axilla. • The inferior glenohumeral ligament appears thickened in shoulders with capsular contracture. • Capsular contracture ultrasound features can be associated with other rotator cuff problems.

Acromiohumeral distance in a seated position in persons with impingement syndrome.

To compare the acromiohumeral distance (AHD) of both shoulders in subjects with a unilateral shoulder impingement syndrome (SIS) and healthy subjects in a seated position during free shoulder movements of large amplitude. Using a 0.5-Tesla SIGNA-SP/i trade mark open-configuration magnetic resonance imaging (MRI) system, the AHD was measured at several arm positions, in a standardized seated position. In flexion (rest to 130 degrees ), the mean AHD of SIS varied from 8.3 to 2.8 mm, as compared to from 8.7 to 4.1 mm for asymptomatic contralateral shoulders. In abduction (rest to 110 degrees ), the AHD varied from 8.1 to 3.4 mm and from 8.8 to 4.6 mm for SIS and asymptomatic shoulders, respectively. The smallest AHD (P <.01) was observed at 110 degrees. From 80 degrees of arm elevation, the AHD was significantly smaller in impingement than in asymptomatic shoulders (P <.05). The AHD of asymptomatic shoulders did not differ from that of healthy subjects. In SIS, the AHD at rest was correlated with its reduction at all shoulder positions (r(p) = 0.62-0.88), but was a poor predictor of the smallest AHD observed at 110 degrees (flexion, R(2) = 0.09; abduction, R(2) = 0.08). In the critical arm elevation positions for impingement, AHD is discriminative for SIS, compared to asymptomatic shoulders and healthy ones. AHD at rest is a good indicator of the magnitude of its reduction in elevation, but not of the smallest AHD in arm elevation.

Scapular behavior in shoulder impingement syndrome

Hébert LJ, Moffet H, McFadyen BJ, Dionne CE. Scapular behavior in shoulder impingement syndrome. Arch Phys Med Rehabil 2002;83;60-9. Objective: To quantify the contribution of each scapular rotation to the scapular total range of motion (ROM) in both shoulders of persons with a unilateral shoulder impingement syndrome (SIS), to compare 3-dimensional (3D) scapular attitudes of their symptomatic and asymptomatic shoulders in flexion and in abduction, and to characterize the scapular behavior of these subjects by classifying them into subgroups based on scapular tilting differences between their symptomatic and asymptomatic shoulders. Design: Comparisons of 3D scapular attitudes, scapular total ROM, and percentage of contributions of each scapular rotation to the scapular total ROM. Setting: A motricity laboratory. Participants: Fifty-one subjects, including 41 with a SIS (29 had an asymptomatic contralateral shoulder) and 10 healthy subjects. Interventions: The 3D scapular attitudes were calculated with the subjects in a standardized seated position; with the arm at rest; or at 70°, 90°, and 110° of shoulder flexion and abduction. Axial rotation angles were calculated using a fixed set of Cardanic angles. Main Outcome Measures: At 90° of arm elevation, data from 10 shoulders of healthy subjects were used to set up normative values (99% confidence interval of mean 3D scapular attitudes) to compare with 3D scapular attitudes of symptomatic and asymptomatic shoulders of SIS subjects. We analyzed the scapula behavior of subjects with SIS and classified them into subgroups based on scapular anterior tilting asymmetry. Results: In flexion, almost half of the scapular total ROM was provided by anterior tilting (48.2%-51.3%), whereas in abduction, external rotation (40.3%-42.4%) was the main contributor. Scapular total ROM was higher in abduction than in flexion in all arm positions for both shoulder groups (P <.01). Also, 3D scapular attitude patterns of both shoulders of SIS subjects were different from those of healthy subjects. At 90°, scapular asymmetry in anterior tilting allowed us to classify SIS subjects with respect to more (lead) or less (lag) scapular tilting in the affected side (P <.0001) or no difference (P =.11) between the sides (symmetrical). No significant differences (P >.05), except for a small 2° difference in transverse rotation during arm flexion at 110° (P =.002), were observed in 3D scapular attitudes and scapular total ROM between both shoulders of SIS subjects. Patterns of 3D scapular attitudes and scapular total ROM were significantly different between flexion and abduction arm positions (P <.05). Conclusions: The contribution of rotations and scapular total ROM differed according to the plane of arm elevation in SIS subjects. Group analyses revealed no differences in 3D scapular attitudes between symptomatic and asymptomatic shoulders of subjects with unilateral SIS. This could be caused by the use, in SIS subjects, of inappropriate neuromuscular strategies affecting both shoulders. However, individual analyses revealed scapular asymmetry in the sagittal plane, which suggests that SIS subjects with less anterior tilting in the symptomatic shoulder, as compared with the asymptomatic contralateral one, may be at high risk of developing chronic SIS. This last finding provides scientific evidence to focus rehabilitation protocols toward a restoration of anterior tilting. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

MRI Findings of Asymptomatic Contralateral Shoulders in Patients with Rotator Cuff Tears

MRI Findings of Asymptomatic Contralateral Shoulders in Patients with Rotator Cuff Tears