Capsulolabral augmentation by blood injection increases the intrinsic stability provided by the glenoid

To test the hypothesis that the intrinsic stability of the cadaveric glenoid can be augmented by the injection of blood into the labrum.

The intrinsic stability of 10 fresh frozen cadaveric glenoids was assessed by measuring the balance stability angle. Pretreatment values of 8 directions in each glenoid were obtained. The labrum was then injected with blood freshly drawn from a volunteer. After the injected blood clotted, measurements of the balance stability angle of the 8 directions were again obtained.

The mean pre-injection balance stability angle for 7 of the 8 directions were significantly increased by the injection of blood: anterosuperior, from 25 to 35 degrees (p<0.005); anterior, from 27 to 34 degrees (p<0.01); anteroinferior, from 36 to 39 degrees (p<0.005); inferior, from 38 to 41 degrees (p<0.02); posteroinferior, from 35 to 42 degrees (p<0.01); posterior, from 27 to 35 degrees (p<0.0005); and posterosuperior, from 26 to 29 degrees (p<0.005). Cross-sections of injected labra demonstrated a firm clot within the labrum with substantial increases in thickness.

The intrinsic stability of cadaveric glenoids can be significantly augmented by the injection of blood into the labrum. It is possible that blood injection may be a useful primary or adjunct procedure in the open or arthroscopic management of glenohumeral instability.