Influence of defect size and localization on the engagement of reverse Hill-Sachs lesions.

Background: Reverse Hill-Sachs (RHS) lesions can cause recurrent posterior shoulder instability because of engagement with the posterior glenoid rim; however, the effect of defect size and localization have yet to be determined.

Hypothesis: Both size and localization are critical for the engagement of an RHS defect with the posterior glenoid rim.

Study Design: Controlled laboratory study.

Impact of constrained dual-screw anchorage on holding strength and the resistance to cyclic loading in anterior spinal deformity surgery: a comparative biomechanical study.

Study Design: Biomechanical in vitro laboratory study.

Objective: To compare the biomechanical performance of 3 fixation concepts used for anterior instrumented scoliosis correction and fusion (AISF).

Summary Of Background Data: AISF is an ideal estimate for selective fusion in adolescent idiopathic scoliosis.

Implications of the center of rotation concept for the reconstruction of anterior column lordosis and axial preloads in spinal deformity surgery.

Object: In thoracolumbar deformity surgery, anterior-only approaches are used for reconstruction of anterior column failures. It is generally advised that vertebral body replacements (VBRs) should be preloaded by compression. However, little is known regarding the impact of different techniques for generation of preloads and which surgical principle is best for restoration of lordosis.

The Humerusblock NG: a new concept for stabilization of proximal humeral fractures and its biomechanical evaluation.

Background: The Humerusblock NG represents a new semi-rigid angular stable fixation device for minimally invasive stabilization of proximal humeral fractures. This study evaluates the function and stability of the Humerusblock NG and its biomechanical properties on the basis of two different fracture models under cyclic loading.

Methods: Six fresh frozen human humeri were tested in a dynamic shoulder joint abduction motion test bench, simulating abduction between 15° and 45°.