ePoster #123 - ISHA Annual Scientific Meeting 2016

An Anatomic Analysis of Mid-Anterior and Anterolateral Approaches for Hip Arthrocentesis

Jacob D. Mikula, BS, Vail, CO UNITED STATES
Jason M. Schon, BS, Vail, CO UNITED STATES
Chase S. Dean, MD, Vail, CO UNITED STATES
Jorge Chahla, MD, Vail, CO UNITED STATES
Renato Locks, MD, Vail, CO UNITED STATES
Alex W. Brady, MSc, Vail, CO UNITED STATES
Robert F. LaPrade, MD, PhD, Vail, CO UNITED STATES
Marc J. Philippon, MD, Vail, CO UNITED STATES

Steadman Philippon Research Institute, Vail, CO, UNITED STATES

FDA Status Not Applicable

Summary: This study analyzes the safety and efficacy of a non-image guided mid-anterior and anterolateral approaches to the hip joint and presents specific angles utilized to enter the capsule.

Abstract:
Background: The ability to safely and reliably enter the hip capsule is highly relevant because of the increased popularity of hip arthroscopy and orthobiologic injections. To our knowledge there has been no reports analyzing the trajectory and angles needed to enter the hip joint capsule for the mid-anterior and anterolateral approaches to the hip.

Purpose/Hypothesis: The purpose of this study was to determine the accuracy and safety of a non-image guided modified mid-anterior approach to the hip joint as described by the senior author for injections and arthrocentesis of the hip joint and to compare it with a standard anterolateral approach. The null hypothesis was that no difference will be observed between the two non-image guided techniques.

Methods: Six pairs (n = 12) of fresh-frozen human cadaveric hemi-pelvises underwent hip injections through either the mid-anterior or the anterolateral approach with 0.1% methylene blue. The distance from the mid-anterior approach to the lateral femoral cutaneous nerve (LFCN) was measured with a digital caliper. To determine the positioning of the needle, a coordinate frame system was defined for the femur with the hemi-pelvis to define the proximal-distal, anterior-posterior and medial-lateral axes as well as the trajectory of the needle. Needle orientation was defined by a combination of two rotations. Distal Angle was defined as the angle between the lateral axis and an intermediate needle position, in the coronal plane, towards the distal axis. Anterior Angle was defined as the angle between the intermediate needle position of Distal Angle and the final position, towards the anterior axis.

Results: Methylene blue was successfully injected into the joint capsule in all 6 specimens utilizing the mid-anterior approach and all 6 specimens utilizing the anterolateral approach. The mean distances from the needle to the LFCN for both the mid-anterior and anterolateral approaches was 19.3 ± 7.9 mm and 80.3 ± 28.3 mm, respectively. For the mid-anterior approach, Distal Angle was a mean of 53.9 ± 14.9° and Anterior Angle was a mean of 33.4 ± 15.6°. For the anterolateral approach, Distal Angle was a mean of 14.5 ± 14.2° and Anterior Angle was a mean of 4.5 ± 13.6°.

Conclusion: This study demonstrated that the mid-anterior and anterolateral approaches for non-image guided hip injections or arthrocentesis can be safely and effectively performed, despite the exhibited variability in the quantitative descriptions of these techniques. The landmarks and measurements presented can be used as general guidelines in the clinical setting for hip arthrocentesis and injections.

Clinical Relevance: The high variability of the needle placement and trajectory of the mid-anterior and anterolateral approaches performed in this study demonstrated that these techniques were not easily quantitatively defined. However, both of these approaches appeared to be safe and effective.