Background: The remplissage procedure may be performed as an adjunct to Bankart repair to treat recurrent glenohumeral dislocation associated with an engaging Hill-Sachs humeral head defect. The purpose of this in vitro biomechanical study was to examine the effects of the remplissage procedure on glenohumeral joint motion and stability.
Methods: Cadaveric shoulders (n = 8) were mounted on a biomechanical testing apparatus that applies simulated loads to the rotator cuff and the anterior, middle, and posterior heads of the deltoid muscle. Testing was performed with the shoulder intact, after creation of the Bankart lesion, and after repair of the Bankart lesion. In addition, testing was performed after Bankart repair with and without remplissage in shoulders with 15% and 30% Hill-Sachs defects. Shoulder motion and glenohumeral translation were recorded with an optical tracking system. Outcomes measured included stability (joint stiffness and defect engagement) and internal-external glenohumeral rotational motion in adduction and in 90° of composite shoulder abduction.
Results: In specimens with a 15% Hill-Sachs defect, Bankart repair combined with remplissage resulted in a significant reduction in internal-external range of motion in adduction (15.1° ± 11.1°, p = 0.039), but not in abduction (7.7° ± 9.9, p = 0.38), compared with the intact condition. In specimens with a 30% Hill-Sachs defect, repair that included remplissage also significantly reduced internal-external range of motion in adduction (14.5° ± 11.3°, p = 0.049) but not in abduction (6.2° ± 9.3°, p = 0.60). In specimens with a 15% Hill-Sachs defect, addition of remplissage significantly increased joint stiffness compared with isolated Bankart repair (p = 0.038), with the stiffness trending toward surpassing the level in the intact condition (p = 0.060). In specimens with a 30% Hill-Sachs defect, addition of remplissage restored joint stiffness to approximately normal (p = 0.41 compared with the intact condition). All of the specimens with a 30% Hill-Sachs defect engaged and dislocated after Bankart repair alone. The addition of remplissage was effective in preventing engagement and dislocation in all specimens. None of the specimens with a 15% Hill-Sachs defect engaged or dislocated after Bankart repair.
Conclusions: In this experimental model, addition of remplissage provided little additional benefit to a Bankart repair in specimens with a 15% Hill-Sachs defect, and it also reduced specific shoulder motions. However, Bankart repair alone was ineffective in preventing engagement and recurrent dislocation in specimens with a 30% Hill-Sachs defect. The addition of remplissage to the Bankart repair in these specimens prevented engagement and enhanced stability, although at the expense of some reduction in shoulder motion.