Good afternoon. My name is Rory Viswani. I'm a resident at the University of Pittsburgh. I'll be presenting our project, A Novel Three-Dimensional Method of Measuring Labral Encapsular Volume to Predict Recurrent Instability After Arthroscopic Banker Repair. I'd like to thank my co-authors for their contributions to this project. Here are our disclosures. Arthroscopic banker repair has a relatively high failure rate. Various demographic and radiographic risk factors have been identified and are listed here. The variations in capsule and labral morphology and their contributions to recurrent instability postoperatively are poorly understood. Labral size also has not been defined on MRI. The objective of this study were to identify demographic risk factors for postoperative dislocation and to develop a method of measuring labral encapsular volume on MRI. The hypothesis was that an increased number of preoperative dislocations, smaller labral volume and larger capsular volume would all be risk factors for recurrent dislocation. This is a retrospective case control study where cases of patients who had dislocation postoperatively were compared to age and sex match controls who did not. The charts of 289 patients were reviewed. The inclusion criteria is listed here and 95 patients met the inclusion criteria. Preoperative x-ray and MRI were reviewed by two radiologists. The vitreous software was used to measure the 3D volume of the labrum and capsule. The sculpt tool allows the user to trace out a certain structure on the axial and reconstructed coronal and sagittal images to create a 3D model of which the volume is measured. It was found that the vitreous software had a difficult time distinguishing very small or diminutive labrums from the surrounding soft tissues. Therefore, a qualitative measurement of labral volume was also undertaken. It was compared to the width of the glenoid tide mark cartilage and was said to be diffusely small if it was less than the tide mark width. This figure demonstrates how the capsule was measured using the vitreous software. As you can see, the capsule was traced out on the axial coronal and sagittal images, a 3D model was obtained, and the volume of that was measured. This figure demonstrates the same process for the labrum. The labrum was traced out again on the axial coronal and sagittal images, a 3D model obtained, and the volume of that was measured. This figure demonstrates qualitative measurement of the labrum. As you can see, the labrum was compared to the width of the glenoid tide mark cartilage, and if it was smaller than the width, as was the case in this picture, it was said to be a small labrum. This table demonstrates the results of our study. As you can see, there was no significant difference between the case and control groups in terms of the various demographic and radiographic variables. It was found that the case group had a significantly higher number of preoperative dislocations compared to the control group, 3.3 versus 1.9. It was also found that the case group had a significantly higher percentage of patients with diffusely small labrum morphology compared to the control group, 40.5 versus 15.2. It was found that the case group had a four times higher likelihood of having a small labrum morphology compared to control group. Furthermore, it was found that the odds ratio for failure increased with each subsequent preoperative dislocation, such that after six dislocations, a patient was eight times more likely to have a postoperative dislocation. It was also found that patients with small labrums had a higher number of preoperative dislocations, 3.1 versus 2. This study demonstrates that small labrum morphology is associated with a higher risk for postoperative dislocation and an increased number of preoperative dislocations. Furthermore, increased preoperative dislocations was independently associated with a higher risk of postoperative dislocation. A larger capsular volume was not associated with the postoperative dislocation risk, and we introduced a novel method of measuring 3D labral encapsular volume. In conclusion, patients with small labrum morphology and greater number of preoperative dislocations are at a higher risk for recurrent dislocation following arthroscopic banker repair. Early stabilization may be warranted in order to prevent recurrent preoperative dislocations, and patients with small labrum morphology may benefit from additional augmentation. Thank you, and here are some of my references.

Rory Viswani

University of Pittsburgh

Labral Encapsular Volume

Recurrent Instability

Arthroscopic Banker Repair