Safety of Hip Anchor Insertion From the Midanterior and Distal Anterolateral Portals With a Straight Drill Guide: A Cadaveric Study
Authors: Degen Ryan M. , Poultsides Lazaros , Mayer Stephanie W. , Li Angela E. , Coleman Struan H. , Ranawat Anil S. , Nawabi Danyal H. , Kelly Bryan T. 
Published: December 2016

Background: During arthroscopic labral refixation, suture anchors are typically inserted from either the midanterior (MA) portal or the distal anterolateral (DALA) portal; however, no studies have previously compared these techniques. Purpose/Hypothesis: The purpose of this study was to compare acetabular rim accessibility and associated complication rates of anchor insertion from these portals. We hypothesized that rim access would be better from the DALA portal. Additionally, we hypothesized that articular surface perforation would occur more commonly from the MA portal while psoas tunnel perforation would occur more commonly from the DALA portal. Study Design: Controlled laboratory study. Methods: Sixteen pelvic cadaveric specimens (32 hips) were obtained and arthroscopic surgery performed in the supine position. Suture anchors were placed at 7 predetermined locations (9-, 11-, 12-, 1-, 2-, 3-, and 4-o’clock positions). Hips were treated as matched pairs, such that one hip from each specimen had all anchors placed from the MA portal and the other from the DALA portal. Allocation ensured an equal distribution of laterality between groups. After anchor insertion, specimens underwent computed tomography and dissection for further evaluation. Results: Rim accessibility was similar between the groups; anchor insertion was most difficult at the 9-o’clock position, particularly with the MA portal technique, where only 50% (8/16) of attempts were successful, in comparison to the DALA portal technique, where 75% (12/16) of attempts were successful. Additionally, the 4-o’clock position proved challenging to access with the DALA portal technique, where only 75% (12/16) of attempts were successful, compared with 100% with the MA portal technique. The difference in accessibility of these techniques, however, did not reach statistical significance at the 9-o’clock position ( P = .2734) or 4-o’clock position ( P = .1012). Articular surface perforation occurred in 4.48% of all anchor insertion attempts, most commonly at the 3-o’clock position ( P = .0242). From the MA portal, 4.00% (4/100) perforated the joint, compared with 4.95% (5/101) from the DALA portal ( P > .999). Further, there were no significant differences in perforation rates at each location between the techniques ( P > .999). Psoas tunnel perforation occurred in 7.69% of all anchor insertion attempts between 2 and 4 o’clock, with equal rates at each location ( P ≥ .6606). From the MA portal, 4.17% (2/48) perforated the psoas tunnel, compared with 11.63% (5/43) from the DALA portal ( P ≥ .2486). Further, there were no significant differences at each location between the techniques ( P ≥ .4839). There was no association between acetabular version, femoral version, or lateral center-edge angle (LCEA) and articular surface or psoas tunnel perforation, regardless of portal use. Conclusion: Anchor insertion from either the MA or DALA portal appears to confer similar rim access and rates of articular surface or psoas tunnel perforation, with a cumulative rate of 4.48% and 7.69%, respectively. Rates of perforation did not differ between the portals and were not associated with acetabular or femoral version or LCEA. Clinical Relevance: Caution should be employed when inserting anchors for labral refixation, particularly in anterior and medial locations (2-4 o’clock), as articular surface and psoas tunnel perforation may occur at a rate higher than previously anticipated. Portal selection does not appear to influence these outcomes.