Osteochondral autograft and hemiarthroplasty for bilateral locked posterior dislocation of the shoulder.

Posterior shoulder dislocations are rare and account for less than 4% of all shoulder dislocations, with only 6.6% of these proving to be bilateral. More importantly, the majority of posterior shoulder dislocations continue to represent a diagnostic trap for the unwary physician who first sees patients with this condition. This report describes the treatment of a locked bilateral posterior dislocation of the shoulder with an associated impression fracture of both articular surfaces of the humeral heads due to an epileptic seizure. The osteochondral autograft obtained from the left humeral head was sutured to the dominant (right) side and the hemiarthroplasty was performed on the contralateral non-dominant shoulder. Posterior bilateral dislocation of the shoulder is still a diagnostic challenge. In the chronic setting, bilateral hemiarthroplasty should be postponed as long as possible since posterior bilateral dislocation is usually experienced by middle-aged active males.

The pectoralis major tendon as a reference for restoring humeral length and retroversion with hemiarthroplasty for fracture.

The success of anatomic reattachment of the tuberosities in proximal humeral fractures, treated with hemiarthroplasty, correlates with functional results. The purpose of this study was to determine the value of the upper edge of the pectoralis major insertion (PMI) as a landmark to establish the proper height and version of hemiarthroplasty implanted for proximal humeral fractures. Twenty cadaveric humeri were studied by CT scan to analyze the relationship between the PMI and humeral height and retroversion. The mean distance from the PMI to the tangent to the humeral head was 5.64 cm. The mean distance of the PMI to the posterior fin of the prosthesis was 1.06 cm. The mean angle between the PMI and the posterior fin of the prosthesis was 24.65 degrees. The upper edge of the pectoralis major insertion constitutes a reproducible reference point to restore proper humeral height and retroversion in hemiarthroplasty for proximal humeral fracture.

Factors affecting meniscal extrusion: correlation with MRI, clinical, and arthroscopic findings.

The existence of meniscal extrusion is well known in the natural history of the osteoarthritic knee. However, extruded menisci are also seen in non-pathologic knees. To ascertain the prevalence of meniscal extrusion in non-arthritic patients, the MRIs of 100 knees were prospectively studied. The data were correlated both with clinical and operative arthroscopic findings. The results showed 68.5% of the medial menisci to have some degree of extrusion, averaging at 28% of the meniscal size. While the lateral meniscus were extruded in 18.8% of cases at an average of 15% of the meniscal size. Furthermore, a relationship between the anterior insertion variant of the anterior medial meniscus and meniscal extrusion was found (P=0.001) in this series. The results suggest meniscal extrusion to be much more common in non-arthritic knees than previously estimated. The results also suggest that when the anterior horn of the medial meniscus inserts anteriorly in the tibial plateau, the meniscus tends to be extruded. It must be kept in mind that one of the limitations of this work is that the MRIs are taken in a non-weightbearing position.