The PIVOT App: A User Guide.

BACKGROUND

While the pivot shift examination is often regarded as the gold standard test for diagnosis of anterior cruciate ligament (ACL) injury, one of the pitfalls of the pivot shift test is that it lacks standardization among physicians. The PIVOT App is a validated application to quantify the amount of tibial translation during the pivot shift maneuver and improve standardization of clinical measurement.

INDICATIONS

The PIVOT App can be used in both clinic and operating room settings for patients who sustained injury to the ACL. The PIVOT App may assist in identifying the amount of rotatory knee laxity in patients with ACL deficiency or following ACL reconstruction.

TECHNIQUE DESCRIPTION

The PIVOT App works by quantifying the amount of translation in the lateral tibia relative to a marker on the lateral femoral epicondyle. To use the PIVOT App, 3 yellow circle stickers are placed on the bony prominences of the lateral knee: the lateral epicondyle, Gerdy's tubercle, and the "pivot point" 3 cm posterior to Gerdy's tubercle parallel to the joint line. Once placed, the pivot shift flexion maneuver can be recorded in the PIVOT App and analyzed to identify both the distance of spontaneous tibial reduction during the pivot shift maneuver and the time of reduction in seconds. The most common problems encountered while using the application include (1) improper marker placement, (2) interference of marker tracking with yellow color in the background, (3) interference of marker tracking with overhead lighting, and (4) extraneous data collection before and after pivot shift flexion.

RESULTS

Previous studies have validated the PIVOT App to accurately distinguish normal, low-grade, and high-grade pivot shifts with resultant increasing tibial translation in the lateral compartment of the knee. The PIVOT App has been used at institutions worldwide to quantify and standardize measurement of the pivot shift.

CONCLUSION

The PIVOT App is a validated application to quantify the amount of lateral tibial translation and reduction during the pivot shift maneuver. Proper use and avoidance of complications while using the application can aid clinicians in accurate diagnosis of rotatory knee laxity in patients following ACL injury.

PATIENT CONSENT DISCLOSURE STATEMENT

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.