Combined fractures of the humeral head and the glenoid

A Unique Presentation of the Glenoid, Coracoid, and Proximal Humerus Fractures

Fractures of the proximal humerus are common injuries with a bimodal age distribution. They usually present in younger patients after high-energy trauma and in elderly patients after lower-energy trauma. Fractures of the proximal humerus are rarely associated with concomitant fractures of the glenoid, and this is a complex injury pattern that indicates the presence of significant instability. Such injuries are usually treated surgically. Even more rarely, patients may present with proximal humerus fractures and fractures of the coracoid process. A male patient presented to our emergency department (ED) after a fall off the loading platform of his heavy goods vehicle (HGV), resulting in a right shoulder injury. During his initial assessment in ED, a computerised tomography (CT) scan demonstrated the presence of a comminuted proximal humerus fracture, a comminuted anterior glenoid wall fracture, and a coracoid process displaced fracture. Surgical fixation of all three fractures was undertaken in the same sitting. This is the first case described in the literature with a combination of the above injuries and serves as a reminder that as trauma complexity and incidence continue to increase, we should maintain a high index of diagnostic suspicion when dealing with such patients. Furthermore, we present our treatment approach for this case and the rationale behind it.

The Biomechanical Effect of Bone Grafting and Bone Graft Remodeling in Patients With Anterior Shoulder Instability

BACKGROUND

Individual constitutional differences in glenoid shape and bone remodeling require a patient-specific and longitudinal approach to evaluate the biomechanical effects of glenoid bone grafting in patients with anterior shoulder instability.

PURPOSE

To quantify the longitudinal, in vivo, biomechanical effects of bone grafting, bone graft remodeling, and glenoid shape in patients with anterior shoulder instability by means of patient-specific finite element models.

STUDY DESIGN

Descriptive laboratory study.

METHODS

In total, 25 shoulders of 24 patients with anterior shoulder instability and anterior glenoid bone loss underwent an arthroscopic iliac crest bone graft transfer (ICBGT) procedure with either autologous or allogenic bone. Patient-specific finite element simulations based on preoperative, postoperative, and follow-up computed tomography scans were used to quantify the bone-mediated stability ratio (SR) and the distance to dislocation. Additionally, the relationship between glenoid morphological parameters and the SR was assessed.

RESULTS

The ICBGT procedure significantly increased the SR and distance to dislocation in the 2-, 3-, and 4-o'clock directions immediately after the surgical intervention (P < .01) in both the autograft and the allograft groups. Although the SR and distance to dislocation decreased subsequently, autografts showed long-term effects on SR and dislocation distance in the 3-o'clock direction (P < .01) and on SR in the 4-o'clock direction (P < .01). Allografts showed no significant effect on SR and dislocation distance in long-term follow-up (P > .05). Overall, glenoid retroversion as well as cavity depth predicted stability in all 4 dislocation directions, with glenoid cavity depth showing the highest correlation coefficients (R = 0.71, 0.8, 0.73, and 0.7 for 2-, 3-, 4-, and 5-o'clock, respectively).

CONCLUSION

The autologous ICBGT procedure biomechanically improved anterior shoulder stability in long-term follow-up, whereas the use of allografts did not show any bone-mediated biomechanical effect at follow-up due to resorption. Furthermore, in addition to measurements of defect extent, the glenoid depth and version seem to be useful parameters to determine the biomechanical effect and need for glenoid bone grafting in patients with shoulder instability.

CLINICAL RELEVANCE

This study proposes the use of autologous bone grafts for a successful long-term stabilization effect. Additionally, this study proposes additional glenoid morphological measures to predict shoulder stability.