Gleno Humeral Joint

The purpose of this study is to do a comparative analysis of glenoid loosening with Inlay vs Onlay glenoid fixation using both press-fit and cement-bonded fixation technique. Our purpose was to see which type of implant and fixation combination would be best for prescription to the patients. A Finite Element Analysis was carried out to analyze the micromotion and stresses generated at the interface of the block and the implant when subjected to axial loading, and the results were validated by experimental physiologic testing with a metal humeral head for the glenoida loosening.

The purpose of this study was:

1.) to measure the change in the Rotator Cuff (RC) moment arm as the shoulder goes through abduction,

2.) to estimate how the individual rotator cuff muscle fibers function during shoulder abduction when the intact rotator cuff goes through partial (50%) and complete supraspinatus tear, and

3.) to demonstrate that the RC joint doesn’t always work as a single muscle unit, but rather performs resultant movement through a combination of different muscle fibers.

Our results demonstrate that as the shoulder went from intact RC to supraspinatus partial and complete tear, the moment arm values showed variability in length at 0 degrees and as shoulder abducted from 0 to 90 degrees. Also, RC muscles while performing a core action can perform a combination of elongation, shortening or remaining constant to bring about a resultant movement. We also show that within any single muscle of the RC, individual muscle fibers may act with opposing moment arms in different directions during shoulder abduction depending upon how which fibers of the muscle is taken into consideration.

The objective of this study was to measure and compare the change in the Rotator Cuff (RC) moment arm as the shoulder goes through abduction for RC conditions:

1.) Intact RC and

2.) Shoulder with Supraspinatus tear corrected with Superior Capsular Reconstruction (SCR) and

3.) Shoulder with Supraspinatus tear corrected with Reverse Shoulder Arthroplasty (RSA).

Our results show that over the course of abduction, SCR and RSA models provided an improved return to normal joint function close to Intact RC shoulder joint illustrating why these joint repair methods are highly utilized surgical options. We also see that RSA maintains slightly closer moment arm length values to Intact RC as compared to SCR.

New arthroscopic transosseous techniques of rotator cuff repair became available in the recent years, with good post-operative outcomes documented in the literature. In response to renewed interest in transosseous repair, we aimed to identify the tunneling angle that can strengthen the bone-suture interface of the transosseous repair. We hypothesized that a significant association exists between tunneling angle and the ultimate pullout load of the bone-suture construct. Additionally, we aimed to determine whether tunnel length and bone quality affect this association and interface.