[MRI of the shoulder. Degenerative changes and rotator cuff tears]

Primary and Secondary Consequences of Rotator Cuff Injury on Joint Stabilizing Tissues in the Shoulder

Rotator cuff tears (RCTs) are one of the primary causes of shoulder pain and dysfunction in the upper extremity accounting over 4.5 million physician visits per year with 250,000 rotator cuff repairs being performed annually in the U.S. While the tear is often considered an injury to a specific tendon/tendons and consequently treated as such, there are secondary effects of RCTs that may have significant consequences for shoulder function. Specifically, RCTs have been shown to affect the joint cartilage, bone, the ligaments, as well as the remaining intact tendons of the shoulder joint. Injuries associated with the upper extremities account for the largest percent of workplace injuries. Unfortunately, the variable success rate related to RCTs motivates the need for a better understanding of the biomechanical consequences associated with the shoulder injuries. Understanding the timing of the injury and the secondary anatomic consequences that are likely to have occurred are also of great importance in treatment planning because the approach to the treatment algorithm is influenced by the functional and anatomic state of the rotator cuff and the shoulder complex in general. In this review, we summarized the contribution of RCTs to joint stability in terms of both primary (injured tendon) and secondary (remaining tissues) consequences including anatomic changes in the tissues surrounding the affected tendon/tendons. The mechanical basis of normal shoulder joint function depends on the balance between active muscle forces and passive stabilization from the joint surfaces, capsular ligaments, and labrum. Evaluating the role of all tissues working together as a system for maintaining joint stability during function is important to understand the effects of RCT, specifically in the working population, and may provide insight into root causes of shoulder injury.

Clavicular hook plate may induce subacromial shoulder impingement and rotator cuff lesion--dynamic sonographic evaluation

Background

Clavicular hook plates are effective fixation devices for distal clavicle fractures and severe acromioclavicular joint dislocations. However, increasing number of studies has revealed that subacromial portion of the hook may induce acromial bony erosion, shoulder impingement, or even rotator cuff damage. By sonographic evaluation, we thus intended to determine whether the presence of hook plate may induce subacromial shoulder impingement and its relationship relative to surrounding subacromial structures.

Methods

We prospectively followed 40 patients with either distal clavicle fracture or acromioclavicular joint dislocation that had surgery using the Arbeitsgemeinschaft für Osteosynthesefragen (AO) clavicular hook plate. All patients were evaluated by monthly clinical and radiographic examinations. Static and dynamic musculoskeletal sonography examinations were performed at final follow-up before implant removal. Clinical results for pain, shoulder function, and range of motion were evaluated using Constant-Murley and Disability of Arm, Shoulder, and Hand (DASH) scores.

Results

Clinically, 15 out of 40 patients (37.5%) presented with subacromial impingement syndrome and their functional scores were poorer than the non-impinged patients. Among them, six patients were noted to have rotator cuff lesion. Acromial erosion caused by hook pressure developed in 20 patients (50%).

Conclusions

We demonstrated by musculoskeletal sonography that clavicular hook plate caused subacromial shoulder impingement and rotator cuff lesion. The data also suggest an association between hardware-induced impingement and poorer functional scores. To our knowledge, the only solution is removal of the implant after bony consolidation/ligamentous healing has taken place. Thus, we advocate the removal of the implant as soon as bony union and/or ligamentous healing is achieved.

[Arthrosis - update 2012]

Osteoarthritis is the most common joint disease in adults. With higher life expectancy and a growing proportion of elderly people in society, the relevance of osteoarthritis is becoming higher, especially in terms of socioeconomic effects and burdens for the healthcare system. In this review the pathogenesis and risk factors of the disease are presented with the focus on the knee, hip and shoulder, clinical symptoms, diagnosis and especially radiological imaging and therapy options.

Prevalence and characteristics of asymptomatic tears of the rotator cuff

We undertook clinical and ultrasonographic examination of the shoulders of 420 asymptomatic volunteers aged between 50 and 79 years. MRI was performed in selected cases. Full-thickness tears of the rotator cuff were detected in 32 subjects (7.6%). The prevalence increased with age as follows: 50 to 59 years, 2.1%; 60 to 69 years, 5.7%; and 70 to 79 years, 15%. The mean size of the tear was less than 3 cm and tear localisation was limited to the supraspinatus tendon in most cases (78%). The strength of flexion was reduced significantly in the group with tears (p = 0.01).

Asymptomatic tears of the rotator cuff should be regarded as part of the normal ageing process in the elderly but may be less common than hitherto believed.

[Open reconstruction of the rotator cuff]

Success rates relating to relief from pain and improved function following open reconstruction of the rotator cuff have been documented in many studies. At least for small to medium-size tears the question currently arises of whether an arthroscopic repair would not also give good treatment results. At present, however, the results of arthroscopic repair are not yet comparable to those yielded by the open techniques, at least in terms of recurrent defects especially in the case of massive tears (affecting more than two tendons). Open surgical repair is currently still recommended for all patients who require maximal postoperative function and strength and for elderly patients. Open repairs have a lower rate of re-rupture than arthroscopic repairs, but arthroscopic repair offers the benefits of lower morbidity. The decision on which technique is indicated should be made by an experienced surgeon with special training in this area and with due consideration for newer aspects in diagnostic imaging techniques, so as to avoid unsatisfactory results. In certain cases of irreparable cuff tears affecting two tendons and with fatty infiltration of the muscle and substantial loss of function muscle transfer can be considered in active patients; this can offer some functional improvement in the medium to long term, but do not lead to full restoration of function.

Correlation between rotator cuff tear and glenohumeral degeneration

We studied the occurrence and correlation between a rotator cuff tear and glenohumeral degeneration. 44 cadaveric shoulders (22 right) were obtained from 32 subjects (18 females), mean age 73 (62-86) years and without a history of systemic diseases. Rotator cuffs were exposed and tear size (14 shoulders) was measured after removal of soft tissue and deltoid. Articular cartilage damage of the glenoid and humeral head was recorded by photography. A grading system of 1 (intact), 2 (mild) and 3 (severe) was used to determine the severity of cartilage damage. The area of articular cartilage damage was calculated using the Sonic Digitizer Analyzing System. The area of articular cartilage damage to the glenoid and the humeral head in the rotator cuff tear group was 32% and 36%, respectively. It was greater than that in the groups without a tear, which was 6% in the glenoid and 7% in the humeral head. However, it was not correlated with the size of the tear. Most of the articular cartilage damage in massive and large rotator cuff tears was located in the anterior-inferior portion of the glenoid and in the posterior portion of the humeral head. The articular cartilage damage area of the glenoid was correlated with that of the humeral head. In conclusion, the area of glenohumeral degeneration was greater in the rotator cuff tear group and was located in a specific site.