Arthroscopically insertable force probes in the rotator cuff in vivo.

In vivo loading data for the rotator cuff would be of value to scientists and clinicians interested in the shoulder. The Arthroscopically Insertable Force Probe (AIFP; Microstrain, Burlington, VT) offers a potential method for collecting this information. A technique for insertion and retrieval of the AIFP from the subscapularis is described. The method was initially established in a cadaveric model. The AIFP was inserted into the subscapularis tendon in 3 volunteers during diagnostic shoulder arthroscopy. After the motor effects of interscalene block had worn off, dynamic data relating to subscapularis tendon loading was collected. The AIFPs were removed through a port site by traction on a 0 (3.5 metric) nylon suture without complications.