Final answer:
For significant degrees of glenoid retroversion, typically around 15 degrees or more, allograft reconstruction of the posterior glenoid is often considered a better option than eccentric anterior reaming to maintain proper joint function.
Step-by-step explanation:
At what degree of glenoid retroversion is allograft reconstruction of the posterior glenoid a better option than eccentric anterior reaming? When considering the mobility and stability of the shoulder joint, provided by the articulation of the humeral head and the glenoid cavity, decisions on surgical interventions like allograft reconstruction versus eccentric reaming must take into account the degree of glenoid retroversion. Generally, a higher degree of retroversion may indicate a preference for allograft reconstruction due to the need for restoring the glenoid anatomy for proper joint function. Retroversion beyond a certain threshold (commonly around 15 degrees, though this threshold can vary based on individual patient anatomy and the surgeon's preference) often suggests that allograft reconstruction could be more beneficial to ensure the stability and motion range of the shoulder joint.