Paresthesias in the distribution marked in yellow in Figure A are consistent with an injury to the Lateral Femoral Cutaneous Nerve (LFCN). The LFCN is at greatest risk of injury with placement of the anterior portal (Portal A in Figure). A properly positioned anterior portal still may cause injury to the LFCN, and therefore the portal incision should be through skin followed by blunt dissection; also known as the "nick and spread" technique. The anterolateral (B) or distal lateral (C) portals may also result in LFCN injury, but the anterior portal is the greatest risk.
Byrd reviewed the indications for hip arthroscopy in athletes. It reviews portal placement and complications.
Robertson et al examined the safety of 11 different hip arthroscopy portals and noted that the greatest risk still comes from the proximity of the anterior portal to the lateral femoral cutaneous nerve. However, a slightly more lateral location seems to provide substantial benefits.
Answer 1: Transient nerve injury affecting the groin (pudendal nerve) is usually due to traction against the perineal post used to distract the hip.
Answer 2: An anterior portal that is too far medial risks injury to the femoral nerve.
Answer 4: Transient nerve injury affecting the dorsum of the foot (peroneal) are usually due to traction used to distract the hip.
Answer 5: The sciatic nerve does not have sensory branches innervating the distribution in Figure A.
Byrd JW. Hip arthroscopy in athletes. Instr Course Lect. 2003;52:701-9. Review.
PMID:12690895 (Link to Abstract)
Robertson WJ, Kelly BT. The safe zone for hip arthroscopy: a cadaveric assessment of central, peripheral, and lateral compartment portal placement. Arthroscopy. 2008 Sep;24(9):1019-26.
PMID:18760209 (Link to Abstract)