ROTATOR CUFF IMPINGEMENT

[Systematics of injuries of the rotator cuff and biceps tendon]

PERFORMANCE

Injuries of the rotator cuff and the biceps tendon demonstrate different patterns, which can be recognized clinically and radiologically.

ACHIEVEMENTS

These patterns are impingement syndrome with additional trauma, isolated trauma of the rotator cuff and shoulder dislocation causing rotator cuff tears. Furthermore, it is clinically crucial to evaluate the extent of a rotator cuff injury.

PRACTICAL RECOMMENDATION

Magnetic resonance imaging (MRI) is the modality of choice to differentiate these patterns.

The scapular assistance test results in changes in scapular position and subacromial space but not rotator cuff strength in subacromial impingement

STUDY DESIGN

Controlled laboratory study.

OBJECTIVES

To determine the effect of the modified scapular assistance test (SAT) on 3-dimensional shoulder kinematics, strength, and linear measures of subacromial space in patients with subacromial impingement syndrome (SAIS).

BACKGROUND

Abnormal scapular kinematics have been identified in patients with SAIS. Increased scapular upward rotation and posterior tilt, as induced with manual assistance using the SAT, have been theorized to increase subacromial space and may alter shoulder strength.

METHODS

Forty-two subjects (21 with SAIS and 21 controls) participated in this study. The anterior outlet of the subacromial space, measured via the acromiohumeral distance on ultrasound images, and 3-dimensional scapular kinematics, measured using motion analysis, were determined with the arm at rest, and at 45° and 90° of active elevation with and without the SAT. A dynamometer was used to measure isometric shoulder strength. Full factorial mixed-model analyses of variance evaluated the effects of the SAT on variables between groups.

RESULTS

There was an increase in scapular posterior tilt at all angles, upward rotation at rest and 45° of elevation, and acromiohumeral distance at 45° and at 90° with the SAT. The SAT did not alter normalized isometric strength. There were no differences in response to the SAT between the SAIS and control groups.

CONCLUSIONS

Manual scapular assistance using the SAT influences factors associated with SAIS, such as subacromial space and potentially scapular orientation during static arm elevation, but not more so in individuals with SAIS than in healthy individuals. The SAT performed statically may be a way to identify potential subgroups of individuals with SAIS for whom subacromial space narrowing may be a contributing factor.

Shoulder impingement: relationship of clinical symptoms and imaging criteria

OBJECTIVE

To establish, in patients with subacromial impingement syndrome, (1) the relationship between pain and shoulder function, as determined by the Constant score, and morphological findings, as determined by radiographs and magnetic resonance imaging (MRI) and (2) the relationship between acromial shape and minimum acromiohumeral distance (AHD).

DESIGN

Cross-sectional study.

SETTING

Tertiary care center.

PATIENTS

Forty-seven patients (33 males and 14 females; mean age, 51.7 years) with unilateral subacromial impingement syndrome who had failed to respond to conservative therapy for at least 6 months.

INTERVENTIONS

The Constant score was determined preoperatively; acromial shape (type I, flat; type II, curved; and type III, hooked) was evaluated on preoperative outlet view radiographs and oblique sagittal T1-weighted MRIs; AHD was evaluated on preoperative anteroposterior radiographs and oblique coronal T1-weighted MRIs.

MAIN OUTCOME MEASURES

Correlation coefficients and the simple kappa statistic were calculated. Student t test and mean differences with 95% confidence limits were reported for group comparisons.

RESULTS

The Constant score was fairly correlated with AHD (r = 0.39, P < 0.01) but not with acromial shape. Patients with an AHD < or =7 mm on MRI scored significantly lower than those with an AHD >7 (mean difference, 18.5; P < 0.01). Acromial shape and AHD were not correlated, neither on radiographs nor on MRI.

CONCLUSIONS

AHD seems to better reflect the clinical status of patients with subacromial impingement, but without rotator cuff tears, than acromial shape. Acromial shape is not a good descriptor of subacromial space narrowing.

Rim-Rent Tear of the Rotator Cuff: A Common and Easily Overlooked Partial Tear

OBJECTIVE

The purpose of this study was to determine the incidence of rim-rent rotator cuff tears in a population of patients referred for shoulder MRI and to determine the sensitivity of MRI for the detection of these tears.

CONCLUSION

Rim-rent tears are a common type of partial-thickness rotator cuff tear, much more commonly present than has been previously reported. In particular, infraspinatus rim-rent tears are more common than previously believed. Rim-rent tears of the infraspinatus tendon and those involving the anterior-most fibers of the supraspinatus tendon are commonly overlooked on MRI, possibly because of failure to appreciate the high incidence of these types of tears and failure to inspect the anterior-most fibers of the rotator cuff.

Résonance magnétique en pathologie ostéo-articulaire

A major role in imaging of the locomotor apparatus. Today, magnetic resonance imaging (MRI) has replaced invasive explorations such as arthrography or saccoradiculography. However, x-rays and scans must often be performed beforehand. Indisputable indications. MRI is crucial in affections of the spongy bone (tumours, osteonecrosis, algodystrophy, fatigue fractures.) and the soft parts (tumours, myositis, fasciitis.). Depending on the situation. The indications for MRI must be weighed versus a scan or arthro-scan in many situations. In the case of strong suspicion of an internal articular disorder, the arthro-scan currently more precise must be preferred. In cases in which there is little clinical orientation, the MRI is justified because of its capacity for global articular and abarticular exploration.

Acromiohumeral distance in a seated position in persons with impingement syndrome

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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).

CONCLUSION

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.

Interactive and interventional sports medicine imaging

The concepts and clinical potential of interactive magnetic resonance imaging (MRI) in which an examiner manipulates the joint of interest during MRI, and of interventional sports medicine imaging in which radiological guidance is used for targeted therapy of injuries and masses are described. As illustrated by a series of clinical cases, we believe that with further development, interactive MRI will play an important role in the comprehensive evaluation of patients with shoulder pain or dysfunction as well as other joint derangements. Interventional sports medicine takes advantage of the increasingly sophisticated diagnostic value of MRI and the radiologist's ability to use imaging to guide percutaneous therapy. We review our recent experience treating a wide variety of disorders such as cysts, hematomas, and inflammatory disorders, focusing on techniques utilizing ultrasound and MR guidance.