ePoster #304 - ISHA Annual Scientific Meeting 2016

An Evaluation Of The Interportal Capsulotomy Made With The Modified Anterior Portal: Comparable Utility With Decreased Capsule Morbidity

Alexander Weber, MD, Chicago, IL UNITED STATES
Eric Makhni, MD, Chicago, IL UNITED STATES
Benjamin Kuhns, MD, Chicago, IL UNITED STATES
Gregory Cvetanovich
Joshua David Harris, MD, Houston, TX UNITED STATES
Michael Jonathan Salata, MD, Cleveland, OH UNITED STATES
Richard C. Mather, MD, MBA, Durham, NC UNITED STATES
Shane J. Nho, MD, MS, Chicago, IL UNITED STATES
Gift C. Ukwuani, MD, Chicago, IL UNITED STATES

Rush University Medical Center, Chicago, Illinois, UNITED STATES

FDA Status Not Applicable

Summary: We present a novel capsulotomy technique designed to minimize capsulotmy size and damage to the Iliofemoral Ligament.

Abstract:
Background:

Growing biomechanical and clinical evidence suggests that the treating hip arthroscopist must balance creating a capsulotomy large enough to adequately address underlying pathology while not compromising the integrity of the hip capsule, which can potentially lead to iatrogenic instability. After the anterolateral portal is established, the standard anterior portal (SAP) is placed at the center of the anterior triangle; however, the SAP may create an interportal capsulotomy that is much larger than appreciated. The authors have migrated to a modified anterior portal (MAP) to minimize the length of the interportal capsulotomy to a smaller and more reproducible distance from the anterolateral portal. The purpose of the current study was to compare the CSA of hip interportal capsulotomies made with the SAP as compared to the MAP.

Methods:

Ten cadaveric hemipelvis specimens were mounted in the wet lab to simulate hip arthroscopic position. Axial traction was applied to achieve 1 centimeter (cm) of distraction to the cadaveric specimen to simulate the intraoperative traction. A standard anterolateral portal was created at 1cm anterior and 1 cm proximal to the tip of the greater trochanter, and the arthroscope inserted into the hip joint central compartment. Hips were then randomized to SAP (n=5) or MAP (n=5). For the SAP, the spinal was placed at the center of the anterior triangle. For the MAP, the spinal needle was place directly adjacent to the anterolateral portal. Under direct arthroscopic visualization a spinal needle was used to localize the SAP or MAP position. The arthroscopic knife was implemented to create the interportal capsulotomies. Once the capsulotomy was completed the arthroscopic equipment was removed from the hip joint and a Smith-Petersen open approach to the hip joint was performed to the level of the iliofemoral ligament. The length and width of each capsulotomy was measured using digital calipers. The dimensions of the iliofemoral ligament were also recorded. The CSA of each capsulotomy was calculated, as was the length of the capsulotomy as a percentage of total iliofemoral ligament (IFL) side-to-side width.

Results:

The average cadaveric age and weight were no different between the SAP and MAP groups (73.4?2.6 years vs. 73.8?4.6 years (p=0.87) and 148?35 pounds vs. 137?14 pounds (p=0.53)). There was no difference between groups with respect to IFL width at the level of the capsulotomy (SAP 3.71?0.61cm vs. MAP 3.74?0.19cm, p=0.92) or maximum IFL width (SAP 5.22?0.71cm vs. MAP 4.97?0.30cm, p=0.50). The SAP group had significantly larger capsulotomy CSA (SAP 3.23?0.92cm2 vs. MAP 0.78?0.11cm2, p=0.004). In addition, the SAP group had significantly longer capsulotomy length as a percentage of total IFL width (SAP 74.2?14.1% vs. MAP 32.4?3.7%, p=0.0002).

Conclusion:

The interportal capsulotomy created between an anterolateral portal and the MAP is significantly smaller in CSA than the corresponding interportal capsulotomy created with the SAP. In addition, the percentage of total IFL violated is significantly smaller when the MAP is used compared to the SAP. Surgeons should be aware of the amount of the IFL that is incised while performing an interportal capsulotomy.