No abstract

Reverse shoulder arthroplasty indication is steadily increasing in acute displaced proximal humeral fracture. Pain and articular movement results appear better than those with hemiarthroplasty. Our data are similar to the international literature.

Os acromiale consist in a lack of fusion between the different ossification spots of the acromial side of scapula from the age of 23-25 years. A relation between os acromiale and some shoulder pathology like impingement syndrome, cuff tear and subacromial bursitis has been described. The etiology is not already known. The aim of this study was to evaluate the frequency of os acromiale in our population, the link between os acromiale and sex, side and shoulder pathology. 1042 shoulder MRI were evaluated to find out os acromiale and the linked cuff pathology. In our population, the frequency of os acromiale was 3.44% without differences between sexes, with prevalence on the right shoulder. No differences in cuff and bursa pathology were present between affected and unaffected subjects. Os acromiale is an anomaly still underdiagnosed. It is important to be recognized because it allows to make an accurate pre-surgical plan. To make a correct diagnosis, axial MRI cut or TC is necessary.

The etiology and formation pattern of heterotopic ossifications (HO) are still unknown. They occur in soft tissues in which bone does not normally form, near one or more proximal joints. In this article, the authors report a peculiar case of a 31-year-old patient affected by scapulo-humeral ankylosis that occurred about 6 months after a coma, in which two unusual concomitant conditions were observed: HO formation in the scapulo-humeral region and the development of keloids during wound repair. The scapulo-humeral ankylosis was resolved surgically with the removal of the HO, which was then studied morphologically to understand its formation pattern. By light microscopy and transmission electron microscopy, it was observed that heterotopic bone displays the normal microscopic structure of primary bone, in which two types of bone tissue were recognized, i.e., woven-fibered bone, deeply located and produced first, and lamellar bone. This suggests that the pattern of HO formation retraces the ontogenetic steps that normally occur during intramembranous ossification. The authors also discuss the peculiar concomitance of HO formation and keloid development, speculating that, although they are different conditions localized in dissimilar regions, they might be hypothetically triggered by a common event, such as the release of factors likely issued during the coma status.

Tendon lesions induce muscular atrophy, the nature of which has not yet been clearly related to lesion etiology and entity. In the present study, tendon and muscle alterations were assessed after experimental tendon lesion of the Infraspinatus muscle in young rats. The consequences of lesions differed on the basis of both extension and injured tissue vascularization, that is apoptosis and/or degeneration, differing mainly by energy demands: apoptosis requires high energy levels (proportional to vascular supply), but degeneration does not. It is well known that tendons are poorly supplied with blood compared with muscular masses, which are abundantly vascularized. Five weeks after tendon surgical section, tendon/muscle samples were taken for TUNEL and transmission electron microscopy. The structural results reported here identified different tendon/muscle alterations: degeneration of tendon without signs of apoptosis, and atrophy of muscle fibers due only to apoptosis. This led to the formulation of the following hypothetical sequence of events: a tendon lesion, not recovering quickly due to the poor tendon blood supply, results in degeneration of the injured tendon, which, in turn, induces a partial disuse of the muscle mass, which consequently atrophies (proportionally to the severity of tendon lesion) by striated muscular fiber apoptosis. The authors suggest that the different behavior of the two tissues depends on the marked difference in their vascularization.