Safe angle? Anchor placement? What arthroscopist would not associate these words with the “deadman's angle”
The deadman theory of suture anchors: observations along a South Texas fence line.
and the recent heated debate between some daredevil “deadman doubters”
- Clevenger T.A.
- Beebe M.J.
- Strauss E.J.
- Kubiak E.N.
The effect of insertion angle on the pullout strength of threaded suture anchors: a validation of the deadman theory.
- Green R.N.
- Green R.N.
- Donaldson O.
- Meilyr D.
- Evans S.L.
- Kulkarni R.
Biomechanical study: determining the optimum insertion angle for screw-in suture anchors: is deadman's angle correct?.
and Dr. Burkhart himself.
Can the deadman be killed?.
Well, sheathe your swords; let us just see if there is a deadman in the hip. After all, rotator cuff repair in the shoulder and hip labral repair are quite different in their biomechanical and anatomical considerations.
Safe angle of anchor placement in the context of hip arthroscopy has been much less discussed. Hip arthroscopy and, within that, labral repair has been an increasingly common procedure. One possible technical error with deleterious consequences is inadvertent intra-articular damage when placing an anchor. Various portals have been proposed to avoid this. In the present issue, Stanton and Banffy
Safe angle of anchor insertion for labral repair during hip arthroscopy.
examine the safety of the distal anterolateral accessory (DALA) portal in comparison with the anterolateral (AL) and midanterior (MA) portals.
In a well-designed cadaveric study, the authors performed hip arthroscopy on 6 specimens and place metal pins at 4 points (12 o'clock to 3 o'clock) on the clock face from either the MA/AL or DALA portals. The distance from the pin to the article surface was measured using computed tomography scanning. The authors found significant differences in the distance in the anterior position (2 and 3 o'clock) at depths of 6 and 9 mm and in the superior position (12 and 1 o'clock) in all depths apart from the starting point.
This study confirms that the DALA portal allows a better trajectory of drill placement than both the AL or the MA portals, with a trajectory angling away from the joint surface with less risk of joint penetration compared with a more parallel course achieved from the AL or MA portals. These days hip arthroscopy has developed to a degree that experienced, high-volume hip arthroscopists can create portals to suit their needs as long as it is within a safe area.
- Robertson W.J.
- Kelly B.T.
The safe zone for hip arthroscopy: a cadaveric assessment of central, peripheral, and lateral compartment portal placement.
It is worth noting that out of the peritrochanteric portals, the DALA portal is closest to the lateral circumflex femoral artery but the MA portal can also be very close to branches of this vessel. Most reassuringly, however, for the budding hip arthroscopist, this current study showed there was no incidence of joint penetration from any pin placement, regardless of the portal.
This is a useful study to further guide the hip arthroscopists among our readers in a rapidly progressing and increasingly more complex field. The risks and benefits of using less common portals have to be further considered, but at least there is no rotator cuff to take into account and no need to worry about the deadman.
© 2016 by the Arthroscopy Association of North America