Para qué se utiliza la técnica del boneblock en la cirugía del hombro

The purpose of the bone block technique in shoulder surgery is to restore stability to the shoulder joint by reconstructing bone loss on the glenoid, thereby preventing recurrent dislocations.

This technique is primarily employed in cases of anterior or posterior shoulder instability where there is significant bone loss of the glenoid surface, typically greater than 15%-20%, a threshold beyond which soft tissue repair alone (e.g., Bankart repair) has a high failure rate.

Bone block procedures involve transplanting a bone graft (autograft or allograft) to augment or reconstruct the deficient glenoid bone, filling the defect, and providing a mechanical 'bone blocking effect' that limits abnormal translation of the humeral head, thus stabilizing the shoulder joint.

For anterior shoulder instability with large glenoid bone defects, commonly used bone block techniques include the Latarjet procedure (transfer of the coracoid process with the conjoint tendon), arthroscopic free bone block procedures using iliac crest or distal clavicle autografts, and novel grafts such as acromion bone block transfers which preserve ligament structures (Reverse Latarjet).

The bone block restores the glenoid articular surface, preventing further humeral head dislocation, and in the case of the Latarjet, additional dynamic stabilization occurs via the sling effect of the transferred conjoint tendon and ligamentous reconstruction effects.

Posteriorly, bone block techniques using iliac crest grafts with patient-specific instrumentation also aim to fill posterior glenoid defects and block posterior translation of the humeral head.

Physiologically, the bone block acts as a physical barrier to humeral head displacement by increasing the osseous containment of the glenohumeral joint, which is essential when bone loss compromises the congruity and stability of the shoulder.

Arthroscopic bone block techniques, with either rigid (screw) or nonrigid (suture anchor) fixation, further allow minimally invasive, anatomically precise reconstruction, reducing soft tissue trauma and preserving muscle function, while the graft's fixation method impacts complications and graft incorporation.

Therefore, the bone block technique addresses both the anatomical defect causing instability and provides biomechanical stability through restoring or augmenting the shoulder's bony architecture, reducing recurrence rates and improving joint function.